bluuebunny/crossref_metadata_2025 huggingface dataset:
Academic Family Tree of Professor John Newman
Authors: Sethuraman Vijay A. , Albertus Paul
Published: October 2008

The field of electrochemical engineering, especially the design and analysis of electrochemical systems, has progressed greatly due to the work of Professor John Newman at the University of California, Berkeley. We present the academic family tree of Professor John Newman comprising his students and their students, and a list of theses and dissertations he directed at UC Berkeley. Professor Newman has graduated thirty Masters and forty three PhD students and seventeen have gone on to become faculty members.
Forty Years of Porous Electrode Theory with Battery Applications
Authors: Tiedemann William
Published: October 2008

Contributions to the field of porous electrode theory with battery applications by Professor John Newman are reviewed with particular emphasis on the lead-acid system. Modeling of the lead-acid system starts with first principles and continues with scale-up a complete battery system. Other battery chemistries are also discussed.
Models of Localized Corrosion under Thin Electrolyte Films, Crevice Corrosion, and at Precursor Sites: Analogies and Differences
Authors: Smyrl William H.
Published: October 2008

Localized corrosion continues to be the subject of research because the intense attack of vulnerable metals may cause the loss of properties in engineering structures. It has a heterogeneous character that makes it unpredictable and difficult to characterize in the initial stages of attack. Previous work on galvanic corrosion on heterogeneous surfaces under thin electrolyte films provides a convenient basis on which to continue studies of the phenomena. Models of crevice corrosion have some similarities to atmospheric corrosion with galvanic coupling, and the analogies will be discussed in this paper.
Electrodeposition onto Oxide-Coated Substrates
Authors: Von Gutfeld Robert , West Alan C.
Published: October 2008

Two in situ methods are discussed for plating on metals such as Ti and Al that are generally hard to electroplate due to a naturally occurring oxide film. One method uses an initial, high-voltage pulse to remove the oxide and the second uses an ~10 ns laser pulse with a Nd-YAG frequency doubled laser at 532 nm. In both methods, plating commences immediately after oxide removal, and the films are adherent. Experimental results for Cu, Ni, and Sn plating on Al by the laser plating process are shown, and a mechanism by which the results are achieved is proposed. Finally, the feasibility of implementing the technology in a manufacturing environment is briefly discussed.
The Influence of Nonuniform Current and Potential Distributions on the Impedance Response of a Disk Electrode
Authors: Orazem Mark , Tribollet Bernard
Published: October 2008

John Newman's pioneering analysis of the current and potential distributions on a disk electrode served as a foundation for recent analysis of local impedance measurements. The emergence of new and powerful simulation software has allowed a more detailed comparison between experimental results and theory for both global and local impedance measurements. This work has also led to refinement of concepts such as the local and global Ohmic impedance and new interpretations of constant-phase-element behavior.
Stefan-Maxwell Mass Transport
Authors: Newman John
Published: October 2008

Direct numerical solution of both the multicomponent Stefan-Maxwell equations and the material balances is simpler than inverting the Stefan-Maxwell equations and inserting them into material balances. This approach is applied, as an example, to evaporation through air of acetone and methanol from a liquid mixture, using the three classical models---film model, penetration model, and boundary-layer model. For this system, treated as an ideal-gas mixture in the Stefan-Maxwell formulation, the diffusion coefficients are composition independent.
Transport Properties of Concentrated Electrolytes and their Impact on the Design of Electrochemical Systems
Authors: Fuller Thomas F. , Gallagher Kevin G.
Published: October 2008

Concentrated solution theory as it relates to the design of electrochemical systems is reviewed. Specific examples for lithium ion batteries and PEM fuel cells are presented.
Stress Distribution within Spherical Particles Undergoing Electrochemical Insertion and Extraction
Authors: Verbrugge Mark , Cheng Yang-Tse
Published: October 2008

We examine the effects of surface tension and surface modulus on diffusion-induced stress (DIS) within spherical nano-particles undergoing electrochemical insertion and extraction. By assuming small mechanical deformation characterized by isotropic linear elasticity and a dilute solution within the solid state for the diffusion problem, we are able to generate analytic solutions for the combined problem of mechanical deformation and diffusion of the insertion species. Both the magnitude and distribution of stress are affected by the surface mechanics if the particle diameter is sufficiently small; for example, during insertion, the tensile state at the center of spherical particles may be significantly reduced in magnitude or even converted from hydrostatic tension to compression with decreasing particle radius. This reduction in tensile stress motivates the examination of reducing particle size so as to improve the mechanical stability of electrode materials.
Numerical Method for Transient Stability in Electrochemical Systems -- Reactor and Fuel Cell Case Studies
Authors: Drake Javit
Published: October 2008

This tutorial paper illustrates the application of an entirely numerical linear stability method to previous dynamic models of an electrofluorination reactor and a direct methanol fuel cell. From physics-based non-linear transient equations, linear perturbation equations are constructed and solved in an automated routine. Simulations show the electrofluorination reactor under particular conditions to be dynamically stable only below approximately 60 mA/cm2. The fuel cell stack temperature shows stability from 50 to 400 mA/cm2 particularly when cooled by an aqueous methanol anode stream of ambient temperature and high flow rate. In each case, a discontinuity in transport tends the system towards instability.
Control of Cellular Adhesion within Microfluidic Device using Electrochemical Biolithography and Dielectrophoresis for Cell-Based Assay
Authors: Hashimoto Masahiko , Kaji Hirokazu , Nishizawa Matsuhiko
Published: October 2008

We describe a method to selectively immobilize a type of leucocytes (neutrophils or eosinophils) from a suspension of mixed leucocytes on the site-specific region inside a microchannel. One of the microelectrodes fabricated at the upper wall of the channel was used for locally electrogenerating hypobromous acid that renders the opposite face of the channel protein-adsorptive. Since the patterned layer of poly(ethylene glycol)dimethacrylate, is previously introduced at the channel bottom, the region of protein adsorption can be precisely defined even in the presence of fluid-flow. After antibody was immobilized on the treated region, an ac voltage (1 MHz, 20 Vpp) was applied to the microelectrodes array in the presence of cell suspension flowing through the channel in order to concentrate cells onto the antibody-immobilized region by negative dielectrophoresis force. The results show that the immobilized antibody would selectively recognize the corresponding leucocyte type from the trapped cells to allow their adhesion.
The Role of Organic Additives in the Localized Copper Plating: Flat, Dish, and Domed Shape Copper Bumps
Authors: Castoldi Laura , Lodi Andrea , Visalli Giuseppe
Published: October 2008

The central role of the copper in power technologies depends on its electrical conductivity even if also the metal shape and profile are important parameters: in fact many recent applications in MEMS field require copper deposits showing very flat profile. Through the mask copper electrochemical deposition (ECD) has become a suitable technology in order to get copper bumps showing the required geometrical features. Our aim was to find the plating conditions that permit to get extremely flat copper profile, using a commercial bath (CuBath, ATMI), without neglecting the uniformity and the roughness, by means of the Semitool-Equinox. The organic additive range in the plating bath resulted to be the main responsible of the shape of the copper. This research was very useful in plating very flat copper studs having far good within die (WiDU%) and within wafer (WiWU%) uniformity. The results were implemented in different products.
Cleaning of Gold Interconnection Surface by Low-temperature Hydrogen Annealing for MEMS Device Fabrication
Authors: Sakata Tomomi , Kuwabara Kei , Ono Kazuyoshi , Sato Norio , Machida Katsuyuki , Ishii Hiromu
Published: October 2008

A technique for cleaning a gold surface using a dry process is described for the fabrication of microelectromechanical system (MEMS) devices. X-ray photoelectron spectroscopy (XPS) shows that gold is oxidized after exposure to oxygen plasma used for ashing of organic contaminants or etching of a sacrificial-layer film. On such oxidized gold surface, there are different incubations at the different places, which give rise to non-uniform thickness in film growth by electrochemical techniques, such as electrodeposition and electroplating. A surface analysis by thermal desorption spectroscopy (TDS) revealed that annealing causes oxygen to desorb from the gold oxide. The surfaces were annealed in a vacuum or nitrogen or hydrogen ambient to examine the effectiveness of dry-process surface cleaning. For the annealing in a vacuum and nitrogen ambient, a temperature of over 260° is necessary for the oxide removal. Annealing in hydrogen ambient drastically lowers the cleaning temperature from 260 to 110°.
HF Vapor Release Assessment to Address NEMS Applications
Authors: Lachal Laurent , Auclair Sylvain , Lavios Pascal , Finet Jean-Marc , Assidi Roselyne , Klein Mouna , Vaudaine Marie-Hélène , Delaguillaumie Fanny , Marcoux Carine , Andreucci Philippe , Grange Hubert , Berthelot Audrey , Garcia-Santana Roland , Lasbordes Franck , Lajoinie Emile , Louveau Olivier , Chiaroni Julien
Published: October 2008

Due to the devices downscaling, the HF vapor release process, one of the most effective techniques for MEMS release, becomes more challenging regarding stiction. An initial compatibility study shows that many metals are compatible excepted Ni and Cu. Then a design of experiment (DOE) was performed on thermal oxide wafers to obtain the parameters for a free stiction process. Nevertheless, current MEMS release processes can not be used on NEMS structures due to more aggressive shape factor. The solution to adapt current HF vapor MEMS release process to NEMS consists in the reduction of the etchrate, reducing the water layer on the surface during the etch step and thereby stiction occurrence. For very challenging structures, reducing the etch rate is not sufficient to avoid stiction, heated processes have then to be used.
Silicon Dry Etching Process for High Topography Sub-micro and Nano-devices
Authors: De Luca Anothony , Ritton Frederic , Gelly Marc , Buckley Julien , Heitzman Michel
Published: October 2008

Microelectronic technology developments have been widely used today in MEMS or BIO (1) technologies. Plasma etching was developed more than 30 years ago and commonly used in microelectronic device processing (2). Although MEMS and BIO realizations were also based on this microelectronics standard processing method. But some process developments or sustaining were needed to achieve the high topography of such devices. We have especially developed for sub-micro and nano high topography devices application a silicon etching process based on dry plasma technology. A performed recipe allowed us to fabricate structure similar as these commonly used in MEMS and BIO devices without trenching effect and residual spacer. Etching edge of 800 nm thick silicon layer shown vertical profile compatible with such applications.
Nanowires Synthesis and Characterization for Their Chemical Sensor Application
Authors: Deepak Jyoti , Lu Yijiang , Li J.
Published: October 2008

Recently, we have synthesized different nanowires for chemical sensor application. They are SnO2, SiO2 and Ga2O3 nanowires using the VLS method for synthesis. Their structural, chemical composition and electrical properties have been characterized by using SEM, EDS, X-ray diffraction, and the I-V curves. We have tested sensors with these materials and sensing matrix for ammonia and methane. Sensors are read out by resistance (I/V) measure¬ments. These sensors are operated at room temperature for applications that requires low power consumption, low cost and high sensitivity.
Fabrication of X-ray Grating Using X-ray Lithography Technique
Authors: Noda Daiji , Tsujii Hiroshi , Takahashi Naoki , Hattori Tadashi
Published: October 2008

X-ray radiographic imaging technique is very important in medical, biological, inspection, material science, and so on. However, it is not enough to obtain clear X-ray images of samples with low absorbance materials, such as biological soft tissues. Then, we have used an X-ray phase imaging method of an X-ray Talbot interferometer. In this method, X-ray gratings were required to have narrow pitch and high aspect ratio structure. Therefore, we have developed and fabricated high aspect ratio X-ray gratings with a pitch of 5.3 um, a height of 30 um, and a large effective area of 100 mm × 100 mm using X-ray lithography and narrow electroforming technique. In this paper, we discuss the fabrication process of X-ray gratings and results of X-ray phase tomography using an X-ray Talbot interferometer with these X-ray gratings.
Enhancement of Thermal Properties of Polymer-Coated Noble Metal Nanoparticles Using Plasmid DNA
Authors: Endo Tatsuro , Yanagida Yasuko , Hatsuzawa Takeshi
Published: October 2008

In this study, the enhancement of the thermal properties of polyvinylpyrrolidone (PVP)-coated silver nanoparticles were carried out. For enhancement of thermal properties, the PVP-coated silver nanoparticles-plasmid DNA complex was formed by the adsorption of the plasmid-DNA onto the PVP-coated silver nanoparticle surface. Using this complex, evaluation of the thermal properties was carried out. As a result, after formation of the PVP-coated silver nanoparticles-plasmid DNA complex, enhancement of the thermal properties could be observed.
Cell Cultivation on the Porous Silicon Surface for Cell Chip Application
Authors: Yanagida Yasuko , Naito Shinsuke , Tanaka Yasuhiro , Endo Tatsuro , Hatsuzawa Takeshi
Published: October 2008

In this study, cell cultivation on the porous silicon substrate surface for cell chip application was carried out. For evaluation of cell cultivation characteristics, the cells were cultivated on the different surface structures of the porous silicon substrates. And then, the living cells on the several porous silicon substrates were observed. As a result, differences of the cell cultivation characteristics that depend on the surface structures could be observed.
Comparison of a Microfluidic Gas-Intake Devices with Pillar-Type and Microfluidic Membrane-Type Structures
Authors: Amano Megumi , Arakawa Takahiro , Sato Hironobu , Sekiguchi Tetsushi , Shoji S. , Kudo Hiroyuki , Saito Hirokazu , Mitsubayashi Kohji
Published: October 2008

A microfluidic gas-intake device for measurement of gaseous substances was fabricated and tested. The gas-intake device has a window that provides direct absorption of gas into liquid in microchannels the membrane-type microfluidic device which uses a gas permeability of the PDMS membrane for gas-intake is fabricated and compared gas intake efficiency to the gas-intake device using the dissolution velocity of oxygen into DI water channel. The degree of oxygen saturation was significantly improved (17.5 %) in case of the pillar-type device. This indicates that the pillar-type microstructure is effective for the gas-intake purpose.
Development of Li/(CFx)n Battery at Sandia National Laboratories For Long-Lived Power Sources Applications
Authors: Nagasubramanian Ganesan
Published: October 2008

Recent advances in electrode fabrication and tailoring electrolyte properties for numerous applications have generated wide-spread interest in (CFx)n chemistry since it has the highest theoretical capacity and hence longer life of the four well known Li-primary chemistries. We are applying "Li-ion technology" electrode fabrication methodologies and preparing thin film (CFx)n electrodes in-house for evaluation. In this program we have evaluated 4 different (CFx)n materials for performance in coin cells in the temperature regime -55 to 72oC. We continue to evaluate the top performer in 18650 cell configuration and obtained ~3.6 Ahrs capacity at a C/400 rate. We also evaluated cathodes of different lengths for uniformity of loading. For example, a 36" long x 4.2 mil thick electrode gave 3.6 Ahrs while a 29" long x 4.2 mil thick electrode gave 2.9 Ahrs of capacity. We also measured impedance at different voltages and thermal abuse response of the 18650 cells.
Developing γ-MnO2 Models for XRD Analysis
Authors: Caltagirone Scott , Massingill James
Published: October 2008

The structure of battery-grade gamma-manganese dioxide (γ-MnO2) as described by de Wolff and generally accepted in the battery community is an intergrowth between ramsdellite and pyrolusite domains. Upon heating γ-MnO2, the phase composition changes as the ramsdellite phase converts to pyrolusite. These phase-changed materials have large unit cells that produce X-ray diffraction patterns with broad lines that can be difficult to interpret. We present here a tested method of building γ-MnO2 crystal models with various phase compositions that can be used to better characterize phase-changed manganese dioxide.
Alloying Effects of Co-Sputtered Gold-Platinum Thin Films on the Oxygen Reduction Reaction in Acidic Electrolyte
Authors: Brown Billyde , Wolter Scott D. , Stoner Brian R. , Glass Jeff
Published: October 2008

Co-sputtering was utilized to form metastable solid solution Au/Pt alloy films across the entire range of possible compositions. Homogeneous mixing was achieved without nanoparticle geometries, thereby isolating the effects of alloying from nanoscale size effects on the oxygen reduction reaction (ORR). Furthermore, as-deposited near-surface compositions determined by XPS were within 10% of the bulk compositions determined by EDS indicating that extensive Au surface segregation was avoided by room temperature deposition. The alloys were electrochemically characterized via cyclic voltammetry in Ar-saturated 0.5 M H2SO4 and ORR activity and stability was investigated after O2 saturation under oxidizing potentials. Compositions within the miscibility gap were found to be more electrocatalytic for O2 reduction than the pure Pt film. However, intermediate compositions lacked stability with continuous potential cycling when compared to compositions near the edges of the gap which retained enhanced activity.
Compositions and Properties of Pyrochlore-Type Oxides for Air Electrode in Secondary Cells
Authors: Koga Kohei , Momai Toshihide , Matsunaga Morio
Published: October 2008

The electrochemical properties of pyrochlore-type oxides have been examined to develop the new catalyst for the air electrode of secondary cells. The electrode with Bi2Ir2O7-z catalyst could reduce the overpotential for the oxygen reduction. By substituting with manganese for the B site of Bi2Ir2O7-z catalyst, Bi2Ir2-yMnyO7-z (y=0.3, 0.5, 1), the overpotential for the oxygen reduction reduced at the high current densities. Bi2Mn2O7-z catalyst may possess the ability for the oxygen reduction, even though this catalyst contains no iridium. The lifetime of the air electrodes with Bi2Ir2-yMnyO7-z catalysts became shorter than that with Bi2Ir2O7-z catalyst.
Microbial Fuel Cells for Wastewater Treatment
Authors: Ramasamy Ramaraja P. , Ren Zhiyong , Mench Matthew M. , Regan John
Published: October 2008

In the recent years the power densities of Microbial Fuel Cells (MFCs) have increased by orders of magnitude upon decreasing the internal ohmic resistance of the system. With the ohmic resistance of the MFC systems no longer a dominant issue, identification of other intrinsic resistances is the need of the hour. Electrochemical impedance spectroscopy (EIS) was used to study the impedance behavior of a microbial fuel cell (MFC) during initial biofilm growth in an acetate-fed, two-chamber MFC system with ferricyanide in the cathode using mixed culture of bacteria obtained from activated sludge as the bio-catalyst. Results showed that the kinetics of anode bio-electrochemical reactions were sluggish, thereby contributing to the majority of the polarization loss. Also the anode charge transfer resistance was found to vary during the initial biofilm growth indicating a direct correlation between the microbial processes and the system performance.
AC Impedance Spectroscopy Measured on Different Precious Metals-Electrolyte Interfaces Used for Methanol Fuel Cells by Mean of Two Theoretical Models
Authors: Rosas Omar
Published: October 2008

Methanol electro-oxidation on platinum, ruthenium oxide, and titanium electrodes in contact with different molar ratios of a sulfuric acid solution is characterized electrochemically using electrochemical impedance spectroscopy. A multi-step mechanism of reaction for methanol electro-oxidation is proposed taking into account two different absorbed species simultaneously. The impedance signatures obtained are interpreted by mean of two algorithms, one based on transfer functions and the other based on transmission lines. The "transfer function model" incorporates the surface coverage of the metal by two species as a function of the mechanism of reaction. The "transmission line model" simulates the impedance of a combination of active and covered sites at the metal surface. Theoretical derivations are in good agreement with the experimental results. The low frequency experimental impedance data are explained by the existence of a diffusion layer. The models predict the behavior at the interface at open circuit potential and under polarization conditions.
The Safe and Economic Revival of Alkaline Hydrogen/Air Fuel Cells with Circulating Electrolytes, Recommended for Vehicles Using Battery Hybrid Systems and H2 from Ammonia Crackers
Authors: Kordesch Karl , Hacker Viktor , Reichmann Klaus , Cifrain Martin , Hejze Thomas , Aronsson Robert R.
Published: October 2008

Alkaline Fuel Cells: The Bacon Fuel Cell, the Apollo NASA Space Shuttle and the Russian System. The Allis Chalmers Tractor,the Union Carbide GM-Electrovan, the Kordesch Hybrid Car, the Eloflux and the Elenco System and the European Space Power Plant for Hermes. Also: the Dornier-Siemens and the Swedish Navy System and Olle Lindstroems work. The fuel cells by Hoechst and von ZeTek. A bipolar system was built in Graz and at Apollo Energy Systems, Inc. 2 kW AFCs were tested with NH3. Liquified Ammonia can be converted to 75 % H2 and 25 % N2. The capacity by wt.and vol. of ammonia surpasses methanol. Ammonia is produced worldwide in several 100 million tons per year. Ammonia is available on farms. Refrigerators worked safely with ammonia. Internal Combustion Engines operate on cracked Ammoniamix with increased power and higher efficiency.
Inhibition of Azoxymethane-Induced Colonic Aberrant Crypt Foci Formation by Silibinin in Male Fisher 344 Rats
Authors: Velmurugan Balaiya , Singh Rana P. , Tyagi Alpna , Agarwal Rajesh
Published: October 2008

Chemoprevention is a practical approach to control colorectal cancer, which is one of the major causes of cancer mortality in the United States. Based on our recent silibinin efficacy studies in human colorectal cancer cells, we investigated the effects of its dietary feeding on azoxymethane (AOM)-induced aberrant crypt foci (ACF) formation and associated biomarkers in male Fisher 344 rats. Five-week-old male Fisher 344 rats were fed control or silibinin-supplemented (0.033%, 0.1%, 0.33%, or 1%, w/w) diet. After 2 weeks, AOM was injected once a week for 2 weeks while silibinin treatments were continued. In another protocol, identical silibinin treatments were done but started 2 weeks post-AOM initiation. All rats were sacrificed at 16 weeks of age, and colon samples were evaluated for ACF, followed by proliferation, apoptosis, and inducible nitric oxide synthase and cyclooxygenase-2, by immunohistochemistry and/or immunoblotting. Silibinin significantly (P < 0.001) reduced dose-dependently the number and multiplicity of AOM-induced ACF formation. Silibinin feeding in pre- and post-AOM initiation decreased mean number of ACF by 39% to 65% and in post-AOM initiation by 29% to 55%. Silibinin dose-dependently decreased AOM-induced colonic cell proliferation, evidenced by proliferative cell nuclear antigen and cyclin D1 immunohistochemical staining, and induced apoptosis in these colon tissues, evidenced by terminal deoxyribonucleotidyl transferase–mediated dUTP nick end labeling staining and cleaved poly(ADP-ribose) polymerase. Furthermore, silibinin significantly decreased AOM-induced inducible nitric oxide synthase– and cyclooxygenase-2–positive cells in colon tissues. The present findings show possible beneficial activity of silibinin at least in early stage of colon tumorigenesis, suggesting that silibinin might be an effective natural agent for colorectal cancer chemoprevention.
Stabilization of Quercetin Paradoxically Reduces Its Proapoptotic Effect on UVB-Irradiated Human Keratinocytes
Authors: Olson Erik R. , Melton Tania , Dong Zigang , Bowden G. Tim
Published: October 2008

UVB light promotes survival of initiated keratinocytes, in part, by the direct activation of the phosphatidylinositol 3-kinase (PI3K) signaling pathway. Novel chemopreventative agents targeting UVB-induced signaling pathways are needed to reduce the incidence of nonmelanoma skin cancer. Quercetin (Qu) is a dietary flavonoid and a known inhibitor of PI3K. We determined that Qu degrades rapidly when diluted in DMEM and incubated under normal cell culture conditions. Degradation was delayed by supplementing the medium with 1 mmol/L ascorbic acid (AA), and as expected, stabilization actually increased the effectiveness of Qu as a PI3K inhibitor because basal and UVB-induced Akt phosphorylation were reduced compared with Qu treatment in the absence of AA. Although AA stabilization increased Qu-induced apoptosis in mock-irradiated HaCaT cells, consistent with it acting as a PI3K inhibitor (13.4% Annexin V–positive cells for AA-stabilized Qu versus 6.3% for Qu), AA stabilization of Qu actually reduced the ability of the compound to induce apoptosis of UVB-irradiated HaCaTs (29.7% of Qu-treated cells versus 15.5% of AA + Qu–treated cells). Similar trends were seen in the analysis of caspase-3 and poly(ADP-ribose) polymerase cleavage. Qu is known to oxidize to form reactive products, and we found that dihydroethidium is oxidized by Qu regardless of whether or not it was stabilized. Although redox cycling occurs even in the presence of AA, stabilization reduces the accumulation of reactive Qu products that contribute to the proapoptotic effect of the compound, and thus reduces the ability of the compound to induce apoptosis of UVB-irradiated HaCaT cells.
Evolutionary Convergence of Higher Brain Centers Spanning the Protostome-Deuterostome Boundary
Authors: Farris Sarah M.
Published: October 2008

Currently available evidence supports a single origin for the centralized nervous system of bilaterally symmetrical animals. Beneath the staggering diversity of protostome and deuterostome nervous systems lies a fundamental groundplan consisting of a tripartite brain and a nerve cord divided into distinct antero-posterior and medio-lateral zones. As divergent lineages have taken independent paths towards increased encephalization, complex brain centers have arisen that serve multiple levels of sensory processing and advanced behavioral coordination and execution. Many questions arise as one surveys the distribution of these brain centers across the bilaterian phylogenetic trees. What environments did these lineages encounter that promoted the acquisition of energetically expensive brain centers composed of thousands, millions or even trillions of neurons? What novel behavioral capabilities did these brain centers in turn give rise to? Comparative studies within vertebrate clades have revealed instances of parallelism and convergence that have been instructive in associating evolutionary changes in brain structure and function with specific behavioral ecologies. The present account reviews these findings and extends them to invertebrate animals that have independently evolved higher brain centers. By expanding the scope of comparative studies across phyla, it will be possible to uncover structural and functional constraints imposed by deep homology, and to better understand the environmental pressures that have given rise to brain and behavioral complexity.
Habitat Complexity, Brain, and Behavior
Authors: Shumway Caroly A.
Published: October 2008

More complex brains and behaviors have arisen repeatedly throughout both vertebrate and invertebrate evolution. The challenge is to tease apart the forces underlying such change. In this review, I show how habitat complexity influences both brain and behavior in African cichlid fishes, drawing on examples from primates and birds where appropriate. These species groups share a number of similarities. They exhibit a considerable range of brain to body weight within their group. Often highly visual, the species show a diversity of habitat types, social systems, and cognitive abilities. Phylogenies are well established. In closely-related cichlid fishes from the monophyletic Ectodine clade of Lake Tanganyika, habitat complexity is directly correlated with social variables, including species richness, diversity, and abundance. Total brain size, telencephalic and cerebellar size are positively correlated with habitat complexity. Visual acuity and spatial memory are also enhanced in cichlids living in more complex environments. I speculate that species-specific neural effects of environmental complexity could be the consequence of the corresponding social changes. However, environmental and social forces affect brains differently. Environmental forces exert a broader effect on brain structures than social ones, suggesting either allometric expansion of the brain structures in concert with brain size and/or co-evolution of these structures. To advance our understanding of the mechanism by which habitat complexity affects brain and behavior will require the use of closely-related species, quantification of complexity, hypothesis testing restricting analysis to a single variable and path analyses to explore the order of importance of such variables. We will also need new experimental paradigms exploring the cognitive and survival value of brain and brain structure changes both in the laboratory and in the wild.
Beyond Neuroanatomy: Novel Approaches to Studying Brain Evolution
Authors: Pollen Alexander A. , Hofmann Hans A.
Published: October 2008

The study of the evolution of brain structure and function, although fascinating, has been contentious, largely due to the correlative nature of neuroanatomical comparisons and the often ill-defined categorizations of habitat and behavior. We outline four conceptual approaches that will help the field of brain evolution emerge from a historical focus on descriptive comparative neuroanatomy. First, reliable, efficient and unbiased behavioral assays must be developed to characterize relevant cross-species differences in addition to focused studies of neuroanatomy. Second, developmental and physiological processes underlying neuroanatomical and behavioral differences can be analyzed using the comparative approach. Third, genome-wide comparisons including genome-wide linkage mapping, transcriptional profiling, and direct sequence comparisons, can be applied to identify the genetic basis for phenotypic differences. Finally, signatures of selection in DNA sequence can provide clues about adaptive genetic changes that affect the nervous system. These four approaches, which all depend on well-resolved phylogenies, will build on detailed neuroanatomical studies to provide a richer understanding of mechanistic and selective factors underlying brain evolution.
Functional Tradeoffs in Axonal Scaling: Implications for Brain Function
Authors: Wang Samuel S.-H.
Published: October 2008

Like electrical wires, axons carry signals from place to place. However, unlike wires, because of the electrochemical mechanisms for generating and propagating action potentials, the performance of an axon is strongly linked to the costs of its construction and operation. As a consequence, the architecture of brain wiring is biophysically constrained to trade off speed and energetic efficiency against volume. Because the biophysics of axonal conduction is well studied, this tradeoff is amenable to quantitative analysis. In this framework, an examination of axon tract composition can yield insights into neural circuit function in regard to energetics, processing speed, spike timing precision, and average rates of neural activity.
Electrophoretic Studies on Influenza A2 Virus and its Components
Authors: Ivaničovà S.
Published: October 2008

Purified influenza A2 virus components, prepared by ether treatment and adsorption onto and elution from red blood cells in combination with high-speed centrifugation, were evaluated by moving boundary electrophoresis, hemagglutination, immunodiffusion, UV-spectroscopy and electron microscopy. The nucleoprotein (NP) component, dissociated with sodium dodecyl sulfate (SDS) and 2-mercaρtoethanol (2-ME) and fractionated on SDS-polyacrylamide gels was found to contain a single polypeptide chain.
Untersuchungen zur proteolytischen Enzymaktivität bei Bacillus anthracis und Bacillus cereus
Authors: Müller H.E. , Marklein G.
Published: October 2008

Assuming that B. anthracis might possibly be related to B. cereus an investigation was undertaken to compare the activities of proteolytic enzymes in both germs. As substrates, 18 different human plasma proteins were used. Their behaviour was studied with the appropriate monovalent antisera by immunoelectrophoresis. The pattern of protein alterations was nearly the same in B. anthracis as compared to that of B. cereus. Both organisms caused alterations in α1-lipoprotein, β-Mipoprotein, α2HS-glycoprotein, hemopexin, and fibrinogen. Furthermore, the action of B. cereus led to IgA alteration and one strain even altered haptoglobin and transferrin. β2-Glycoρrotein-I was regularly disintegrated by B. cereus while with B. anthracis this effect could only be demonstrated after an animal passage. Therefore, the enzymatic activity of B. anthracis seems to be augmented by the intensifying effect animal passages have on virulence. The proteolytic activity of B. anthracis is discussed as a component of its pathogenicity.
Chronic Thyroiditis in Buffalo-Strain Rats Ingesting 3′-MethyI-4-Dimethylaminoazobenzene or N-2-Fluorenyldiacetamide
Authors: Reuber M.D. , Glover E.L.
Published: October 2008

Chronic thyroiditis developed in inbred Buffalo-strains rats given 3’-methyl-4-dimethylaminoazobenzene or N-2-fluorenyldiacetamide in the diet. The thyroiditis was observed more often in male than in female animals. Rats with thyroiditis did not have carcinomas of the liver
Interaction between Coxiellae burnetii and the Cells in Experimental Q-Rickettsiosis
Authors: Ariel B.M. , Khavkin T.N. , Amosenkova N.I.
Published: October 2008

Lungs and spleens of white mice were examined after intranasal and intraperitoneal challenge with Coxiellae burnetii, respectively. As a rule, these organisms inhabit lung alveolar macrophages and spleen reticular cells’ vacuoles and are surrounded with a three-layered wall. The vacuoles seem to be formed from phagolysosomes. They are stable structures. When lodged within vacuoles for a long time, Coxiellae preserve viability. Due to the capacity of Coxiellae to parasitize in cellular phagolysosomes, one might consider Q-rickettsiosis as an ‘exoplasmic parasitosis’.
Conidial Release in Pyricularia penniseti
Authors: Singh D.S. , Pavgi M.S.
Published: October 2008

Conidiophores and conidia of Pyricularia penniseti Prasada and Goyal undergo violent hygroscopic movements when transferred from humid to dry atmosphere. The conidia are detached and dispersed forcibly from the conidiophores as a result of these movements. Although the conidia are not projected to long distances, the forcible detachment facilitates further removal by air currents to hasten secondary infection of the younger host leaves in succession.
Suppression by Vitamins D2 and D3 of Hamster Cheek Pouch Carcinoma Induced with 9,10-Dimethyl-1,2-benzanthracene
Authors: Rubin D. , Levij I.S.
Published: October 2008

Local application of vitamins D2 and D3 caused inhibition of tumor formation in the hamster cheek pouch, induced by topical treatment with DMBA. These results and data from the literature are used in an attempt to explain the mechanism of carcinogenesis by DMBA, and the inhibition of this process by vitamin D. In tumor cells the amount of alkaline phosphatase and the amount of calcium bound to the cell membrane are both decreased. It is probable that the protein molecule alkaline phosphatase can also act as calcium binding protein. The decreased amount of calcium bound to the membrane of tumor cells leads to increased permeability, with an increased and less controlled flow of metabolites to and from the cytoplasm, resulting in a decreased control of the mitotic process. Vitamins D cause induction of the synthesis of alkaline phosphatase/calcium binding protein, and this may explain the marked inhibition of DMBA carcinogenesis in animals treated simultaneously with DMBA and vitamin D. This effect of vitamin D is probably not specific, and there are indications that other substances which cause induction of alkaline phosphatase also inhibit tumor formation.
Epiphyseal Growth and Osteoarthrosis in Blotchy Mice
Authors: Silberberg Ruth
Published: October 2008

Blotchy mice which carry a gene causing inadequate cross-linking of collagen were investigated for the progress of epiphyseal growth and for the appearance of changes in the knee joints following cessation of growth. In male mice of the strain, which are hemizygous for the gene, early growth proceeded in a histologically normal fashion, although the metaphyseal bone was less abundant than usual. From the age of 3 ½ months on, the animals developed osteoarthrosis of the knee joints and at the time of death at 5–6t½ months of age, 88% of the animals had osteoarthrosis. The findings are discussed with special reference to a possible role of the collagen of the articular cartilage in the pathogenesis of some forms of osteoarthrosis.
The Migration of Lymphocytes Across Specialized Vascular Endothelium
Authors: Smith Marilyn E. , Sparshott Sheila M. , Ford William L.
Published: October 2008

Radioactively labelled rat lymphocytes were treated in vitro with concanavalin A (con A) and injected intravenously into syngeneic recipients. By examining the blood and tissues at intervals from 30 min to 48 h after injection, it was confirmed that con A altered the distribution of lymphocytes. Comparison was made with the localization of alternatively labelled untreated lymphocytes injected into the same recipients and with untreated lymphocytes injected into other recipients. Within 1 h of injection there was a surplus of treated cells in the lungs and liver and deficits (of equal magnitude) in the blood, spleen and lymphnodes. By 24 h after injection there was a twofold surplus of treated cells in the spleen but a persisting deficit in lymphnodes. These perturbations can be ascribed to the prolonged retention of lymphocytes in normal sites of localization; there is no evidence that con A either hinders the migration of lymphocytes from the blood or diverts them to abnormal sites. It is not clear whether the delay in the recipients’ tissues requires an active response to con A but, if so, then it does not proceed to blastic transformation.
Marked Instability of Character of Cloned Epithelial Cells
Authors: Schnebli H.P. , Burger Marianne , Strasser F.F. , Suter E.
Published: October 2008

Cell lines derived from 7,12-dimethylbenzanthracene-induced rat mammary carcinomas show a marked drift in properties when cultured in vitro. The following characteristics alter progressively with the number of passages: cloning efficiency, requirement for hydrocortisone, requirement for fetal sera, growth response to conditioning factor(s) and ease of detachment from the culture vessel by trypsinization.
Studies on the Product of Antigenic Recognition I.
Authors: Ramseier H. , Lindenmann J.
Published: October 2008

A product of antigenic recognition (PAR) was produced whenever receptors for alloantigens from T lymphocytes or a principle present in T-cell dependent alloantisera interacted with alloantigen. With two forms of the PAR assay (direct and indirect) the mechanisms underlying these interactions have been analyzed. For the interaction of T-lymphocyte receptors with alloantigen measured with direct PAR assays, the following conclusion emerged: upon confrontation with alloantigen, receptors (if not already present in secreted form) had first to be released from T-cell membranes. Shed T-cell receptors interacted with alloantigens by solubilizing them. Both processes could be prevented by fixing cells with formaldehyde. Release of T-cell receptors was temperature-dependent, solubilization of alloantigens was not. Because in mixed cell cultures receptors had first to be shed, this process was considerably slower and, in concordance with temperature dependence of receptor release, took place only at 37 °C. Titration of T lymphocytes with ‘bound’ receptors by the direct PAR test revealed that in the presence of excess alloantigen 102 T cells sufficed to give measurable responses. Supernates of parental strain lymphocytes containing numerous T-cell receptor specificities could be depleted of one of them. Alloantisera raised in presence of T helper cells (‘T alloantisera’) contained a principle capable of recognizing alloantigens, alloantisera incited in the absence of T helpers (‘B alloantisera’) did not. The recognizing principle appeared to be IgG. Like T-cell receptors, it was capable of solubilizing alloantigens form target cell membranes. B alloantisera lacked this capacity and their alloantigen-recognizing moiety was found to be monomeric IgM. The mode of interaction of this IgM with alloantigen most likely consisted in fixation to and shielding of antigen.
Studies on the Product of Antigenic Recognition III.
Authors: Ramseier H. , Lindenmann J.
Published: October 2008

The product of antigenic recognition (PAR) is an antigen-antibody complex with granulotactic activity. The following results support his conclusion. PAR generated by cell-bound or shed T-cell RS or the recognizing structure of T alloantisera and alloantigen can be destroyed by heating at 56 °C for 30 min, because of inactivation of a heat-labile component supplied by alloantigen. Recognizing partners of these complexes are heat-stable. They form PAR anew when alloantigen is added or upon confrontation with anti-RS serum. They are also capable of inducing anti-RS sera. PAR preparations composed of these recognizing structures and antibodies to them are heat-inactivated at much higher temperatures, because both partners of the complex are relatively heat-stable. Heat-labile PAR complexes (recognizing structures and alloantigen) pass anti-mouse immunoglobulin immunosorbent, but are retained specifically by alloantiserum (via alloantigen of the complex) or by anti-RS serum (via RS of the complex) bound to the column.
‘Sezary-Like’ Cells in Malignant and Non-Malignant Diseases
Authors: Rüttner J.R. , Pedio G.
Published: October 2008

Lymphocyte-like distinctive cells with cerebriform and serpentiform nuclei, as described in ‘Sézary syndrome’, were detected in the peripheral blood of two patients, one with plasma-cell leukemia and one with bacterial sepsis. These observations suggest that ‘Sézary cells’ are not strictly specific, neither for a neo-plastic nor for a nonneoplastic disease, but rather representing a reactive form of lymphocytes to different stimuli.
Histopathology of Carcinomas of the Liver in Mice Ingesting Heptachlor or Heptachlor Epoxide
Authors: Reuber Melvin D.
Published: October 2008

C3H male and female mice, ingesting 10 ppm of the pesticides heptachlor or heptachlor epoxide in the diet, developed highly significant incidences of carcinomas of the liver. The carcinomas varied from well-differentiated to poorly differentiated and undifferentiated and were capable of invasion and metastasis.
Influence of Steroid Structure in Relation to Liver Metabolism during Endotoxin Lethality in Mice
Authors: Lazar G. , Sekiya S. , Agarwal M.K.
Published: October 2008

The influence of a number of steroid molecules on hepatic metabolism was determined in relationship to their ability to alter endotoxin lethality in intact mice. Progesterone, testosterone, estradiol, pregnenolone-16-α-carbonitrile and spironolactone did not alter endotoxin lethality, liver glycogen or tryptophan pyr-rolase (TP) levels; all these materials increased liver tyrosine transaminase (TT) levels most probably due to mediation by endogeneously liberated glucocorticoid hormones. Aldosterone and deoxycorticosterone induced liver TP, TT and glycogen but did not protect against lethality. Cortisone, hydrocortisone, triamcinolone, dexamethasone and 9-α-fluorohydrocortisone protected against lethality, increased liver glycogen and TT, but only triamcinolone induced liver TP. Collectively, there was no clear relationship between the protective effect and the increase or decrease of a given liver process. These further emphasize the need to reconsider molecular mechanisms of endotoxic reactions.
Cell-Mediated Cytotoxicity: Comparison of Primary and Secondary Immune Reactions after Parainfluenza Type 1 Virus Inoculation
Authors: Kibler Ruthann , Solvay Maxine J. , ter Meulen Volker
Published: October 2008

H-2 antigen compatibility of effector spleen cells and target cells was necessary for cell-mediated cytotoxicity (CMC) after both 1 and 2 intraperitoneal inoculations of 6/94 virus into mice. T cells were responsible for both primary and secondary CMC reactions. Neither reaction was influenced by the presence of virus-specific antibody added to the test system. Secondary CMC peaked earlier than the primary response and declined more rapidly. In vitro stimulation of primed spleen cells could also be used to detect the secondary CMC response.
The Differentiation of T Lymphocytes
Authors: Hopper Kelvin , Ryden Aina , Shortman Ken
Published: October 2008

Dissociated mouse thymocytes were cultured under optimized conditions in Marbrook vessels in order to follow some aspects of T-cell differentiation. Under particular conditions it was possible to obtain a 50% net increase in the total number of the peripheral T-cell like, minor low Θ thymocyte subpopulation over the first day of culture, although this increase was lost with further incubation. The increase arose from proliferation of preexistent low Θ cells, and not from transformation of the major, high Θ population. Under all conditions the high Θ cells died rapidly in culture. These results are in accordance with the view that the high Θ and low Θ thymocytes represent separate streams of T-cell development. There was a striking increase in responsiveness to phytohemagglutinin and con-canavalin A after culture of thymocytes under these conditions. However, this was ascribed, not to the development of new immunocompetent T cells, but to selective cell death in the cultures eliminating some inhibitory elements. No increase in progenitors of cytotoxic lymphocytes was obtained. The results demonstrate some potential artifacts in assessing the immunocompetence of cultured thymocytes.