bluuebunny/crossref_metadata_2025 huggingface dataset:
Dielectric relaxation and elasticity during polymerization
Authors: Venkateshan K. , Johari G. P.
Published: July 2006

A molecular kinetics-elasticity relation has been investigated by using real time dielectric spectroscopy of a diepoxide-triamine liquid mixture polymerizing at 298K. As the liquid polymerized, the dielectric relaxation time τ increased linearly with the exponential of the known value of the instantaneous shear modulus G∞, in agreement with the elastic model for viscous flow but without the effect of temperature. Thus the structure-dependent effect on the Brownian motions are separated from the temperature-dependent effect. In this time-dependent process, increase in G∞ may be compensated by an increase in T, thereby keeping G∞ and τ constant. In the potential energy landscape paradigm, a polymerizing liquid’s state point, like a normal liquid’s on cooling, continuously shifts to deeper and lower energy minima of higher curvature, but the shift occurs irreversibly to other parts of the total energy landscape, thus adding a reaction coordinate to the landscape. A minimum in the energy landscape corresponding to a structure formed by polymerization may be identical to a minimum in another landscape corresponding to another structure.
Eigen versus Zundel complexes in HCl-water mixtures
Authors: Botti A. , Bruni F. , Ricci M. A. , Soper A. K.
Published: July 2006

There is an ongoing debate on the nature of hydration of the hydrogen ion, H+ in solution, and the extent to which Eigen or Zundel complexes occur. Here, our previous neutron diffraction data on a solution of 1:9 HCl in water are reanalyzed using a new starting hypothesis for the Monte Carlo simulation of the data. Either bare H+ ions, all H3O+ ions, or all H5O2+ ions are allowed in the simulation box together with the water and chlorine ions. All three simulations give a satisfactory fit to the experimental data. From the simulation with simple H+ ions, it is found that all H+ ions form one strong and very short hydrogen bond with water molecules and that on average 75% of them also engage in a second, slightly longer hydrogen bond. This result can be interpreted alternatively either in terms of the formation of a high percentage of asymmetric Zundel complexes or in terms of the formation of distorted H3O+ ions, which in turn form two or three hydrogen bonds, respectively, with neighboring molecules opposite their unbonded hydrogen sites (thus forming Eigen complexes). Therefore the new analysis is not inconsistent with our previous conclusion that the solution consists primarily of Eigen complexes, but does highlight the difficulty of making a clear distinction between Eigen and Zundel complexes due to the continuous random network of hydrogen bonds formed between water and hydrated protons. The role of hydrogen ion to chloride counterion contacts is also discussed in these solutions.
Quantitative mapping of switching behavior in piezoresponse force microscopy
Authors: Jesse Stephen , Lee Ho Nyung , Kalinin Sergei V.
Published: July 2006

The application of ferroelectric materials for nonvolatile memory and ferroelectric data storage necessitates quantitative studies of local switching characteristics and their relationship to material microstructure and defects. Switching spectroscopy piezoresponse force microscopy (SS-PFM) is developed as a quantitative tool for real-space imaging of imprint, coercive bias, remanent and saturation responses, and domain nucleation voltage on the nanoscale. Examples of SS-PFM implementation, data analysis, and data visualization are presented for epitaxial lead zirconate titanate (PZT) thin films and polycrystalline PZT ceramics. Several common artifacts related to the measurement method, environmental factors, and instrument settings are analyzed.
Free energy, entropy and volume of activation for electron transfer reactions in a polar solvent
Authors: Manjari Swati R. , Kim Hyung J.
Published: July 2006

A continuum theory with account of cavity size fluctuations is employed to study free energy, volume and entropy of activation for nonadiabatic electron transfer (ET) reactions in polar solvents. By using a two-sphere cavity description, model calculations are performed for charge separation and recombination processes in acetonitrile under ambient conditions. It is found that the cavity size at the transition state varies with the free energy of reaction as well as with the thermodynamic conditions. In contrast to the Marcus theory predictions, the volume and entropy of activation show a monotonic behavior with the free energy of reaction and a strong correlation with each other. For example, for a given ET process, the volume and entropy of activation have the same sign. Their values for the charge separation and recombination processes are opposite in sign. These findings are in good qualitative agreement with measurements.
Capacitance-voltage characterization of polyfluorene-based metal-insulator-semiconductor diodes
Authors: Yun M. , Ravindran R. , Hossain M. , Gangopadhyay S. , Scherf U. , Bünnagel T. , Galbrecht F. , Arif M. , Guha S.
Published: July 2006

Metal-insulator-semiconductor structures with conjugated polymer ethyl-hexyl substituted polyfluorene (PF2̱6) as the active semiconductor layer, Al2O3 as the insulating oxide layer, and p+-Si as the metal layer have been characterized by means of capacitance-voltage (C-V) and conductance-voltage methods. The negative shift of the flat-band voltage with increasing frequency arises from positive interface charges in the PF2̱6∕Al2O3 layer. From C-V measurements the unintentional doping density is evaluated as ∼5.7×1017cm−3 at frequencies above 20kHz. The interface trap density is estimated as ∼7.7×1011eV−1cm−2 at the flat-band voltage.
Ribosome Binding to and Dissociation from Translocation Sites of the Endoplasmic Reticulum Membrane
Authors: Schaletzky Julia , Rapoport Tom A.
Published: July 2006

We have addressed how ribosome-nascent chain complexes (RNCs), associated with the signal recognition particle (SRP), can be targeted to Sec61 translocation channels of the endoplasmic reticulum (ER) membrane when all binding sites are occupied by nontranslating ribosomes. These competing ribosomes are known to be bound with high affinity to tetramers of the Sec61 complex. We found that the membrane binding of RNC–SRP complexes does not require or cause the dissociation of prebound nontranslating ribosomes, a process that is extremely slow. SRP and its receptor target RNCs to a free population of Sec61 complex, which associates with nontranslating ribosomes only weakly and is conformationally different from the population of ribosome-bound Sec61 complex. Taking into account recent structural data, we propose a model in which SRP and its receptor target RNCs to a Sec61 subpopulation of monomeric or dimeric state. This could explain how RNC–SRP complexes can overcome the competition by nontranslating ribosomes.
An Evaluation of the Risk of Cerebrospinal Fluid Leakage as a Function of the Surgical Approach to the Cochlear Nerve
Authors: Miller Brian Thomas , Hillman Todd
Published: July 2006

Objective: Direct implantation into the cochlear nerve can bypass the potential limitations of conventional cochlear implants. Implantable electrical arrays increase the number of stimulation sites, broaden frequency selectivity, require less activating current, and are not dependent on cochlear anatomy. Cochlear nerve implantation demands a unique surgical exposure to the modiolus. This study comprises an assessment of the risk of generating an intraoperative cerebrospinal fluid (CSF) leak using this approach.

Methods: Five fresh cadavers were obtained for dissection. Using dyed normal saline as an indicator, the central nervous system was pressurized to physiological parameters. Surgical approaches to the cochlear nerve were initiated. Leakage of indicator fluid for each approach was quantitatively and qualitatively assessed. Indicator dye in the surgical field was considered a CSF breech. Indicator fluid was collected and quantified.

Results: Eighty percent of the surgical approaches caused quantifiable leaks with rates ranging from 0.1 mL/minute to 6 mL/minute. For directly implanted microarrays, the utilization of a modified facial recess approach with cochleostomy and modiolar drillout carries significant risk for generating a CSF leak during the procedure.
Nasopharyngeal Pleomorphic Adenoma in the Adult
Authors: Lee Scott L. , Lee C Y. , Silver Steven M. , Kuhar Siobhan
Published: July 2006

Introduction: Salivary gland tumors account for less than 5% of all neoplasms in the head and neck, with pleomorphic adenoma being the most common type. These typically arise in the palate, but we report a rare case of nasopharyngeal pleomorphic adenoma in an adult.

Materials and Methods: The authors conducted a case report and literature review.

Results: The patient presented with unilateral otalgia, tinnitus, and aural fullness. Nasal endoscopy revealed a pedunculated mass adjacent to the left torus tubarius and he was treated with an excisional biopsy. Histologic evaluation demonstrated pleomorphic adenoma.

Discussion: Pleomorphic adenomas seldom present as nasopharyngeal masses and have a nonspecific appearance on endoscopy. Microscopic examination has characteristic features to aid in an accurate diagnosis. Treatment is surgical and recurrence is unlikely.
Lactobacillus cypricasei Lawson et al. 2001 is a later heterotypic synonym of Lactobacillus acidipiscis Tanasupawat et al. 2000
Authors: Naser Sabri M. , Vancanneyt Marc , Hoste Bart , Snauwaert Cindy , Swings Jean
Published: July 2006

The applicability of a multilocus sequence analysis (MLSA)-based identification system for lactobacilli was evaluated. Two housekeeping genes that code for the phenylalanyl-tRNA synthase α-subunit (pheS) and RNA polymerase α-subunit (rpoA) were sequenced and analysed for members of the Lactobacillus salivarius species group. The type strains of Lactobacillus acidipiscis and Lactobacillus cypricasei were investigated further using a third gene that encodes the α-subunit of ATP synthase (atpA). The MLSA data revealed close relatedness between L. acidipiscis and L. cypricasei, with 99.8–100 % pheS, rpoA and atpA gene sequence similarities. Comparison of the 16S rRNA gene sequences of the type strains of the two species confirmed the close relatedness (99.8 % gene sequence similarity) between the two taxa. Similar phenotypes and high DNA–DNA binding values in the range of 84 to 97.5 % confirmed that L. acidipiscis and L. cypricasei are synonymous species. On the basis of the present study, it is proposed that Lactobacillus cypricasei is a later heterotypic synonym of Lactobacillus acidipiscis.
Transfection of Hippocampal Neurons with Plasmid DNA Using Calcium Phosphate Coprecipitation
Authors: Goetze Bernhard , Michael Kiebler
Published: July 2006

INTRODUCTION

This protocol describes transfection of plasmid DNA into primary hippocampal neurons using DNA/calcium-phosphate (CaPO4) coprecipitation. The precise pH of the transfection medium and the incubation time of cells with the coprecipitate are critical for reproducible and efficient transfection. Once these parameters are optimized for a given plasmid, the method is easily adapted for transfection of other established cell lines and primary cell cultures.
Bioresponsive Targeted Charge Neutral Lipid Vesicles for Systemic Gene Delivery
Authors: Li Weijun , Szoka Francis C.
Published: July 2006

INTRODUCTION

This protocol describes a stepwise procedure to prepare nucleic acids encapsulated in a polyethylene glycol (PEG)-shielded nanolipoparticle (NLP) that contain a bioresponsive lipid and ligand. This process provides several advantages for systemic gene delivery. The in vivo circulation time is extended. Also, low pH-sensitive lipids enhance DNA unpacking and endosomal escape. Finally, ligands inserted into the NLP surface can target gene delivery to specific tissues or cells in vivo.
Nonenzymatic biotinylation of a biotin carboxyl carrier protein: Unusual reactivity of the physiological target lysine
Authors: Streaker Emily D. , Beckett Dorothy
Published: July 2006

Enzyme‐catalyzed addition of biotin to proteins is highly specific. In any single organism one or a small number of proteins are biotinylated and only a single lysine on each of these proteins is modified. A detailed understanding of the structural basis for the selective biotinylation process has not yet been elucidated. Recently certain mutants of the Escherichia coli biotin protein ligase have been shown to mediate “promiscuous” biotinylation of proteins. It was suggested that the reaction involved diffusion of a reactive activated biotin intermediate, biotinoyl‐5′‐AMP, with nonspecific proteins. In this work the reactivity of this chemically synthesized intermediate toward the natural target of enzymatic biotinylation, the biotin carboxyl carrier protein, was investigated. The results indicate that the intermediate does, indeed, react with target protein, albeit at a significantly slower rate than the enzyme‐catalyzed process. Surprisingly, analysis of the products of nonenzymatic biotinylation indicates that of five lysine residues in the protein only the physiological target side chain is modified. These results indicate that either the environment of this lysine residue or its intrinsic properties render it highly reactive to nonenzymatic biotinylation mediated by biotinoyl‐5′‐AMP. This reactivity may be important for its selective biotinylation in vivo.
Binding and signaling of surface‐immobilized reagentless fluorescent biosensors derived from periplasmic binding proteins
Authors: de Lorimier Robert M. , Tian Yaji , Hellinga Homme W.
Published: July 2006

Development of biosensor devices typically requires incorporation of the molecular recognition element into a solid surface for interfacing with a signal detector. One approach is to immobilize the signal transducing protein directly on a solid surface. Here we compare the effects of two direct immobilization methods on ligand binding, kinetics, and signal transduction of reagentless fluorescent biosensors based on engineered periplasmic binding proteins. We used thermostable ribose and glucose binding proteins cloned from Thermoanaerobacter tengcongensis and Thermotoga maritima, respectively. To test the behavior of these proteins in semispecifically oriented layers, we covalently modified lysine residues with biotin or sulfhydryl functions, and attached the conjugates to plastic surfaces derivatized with streptavidin or maleimide, respectively. The immobilized proteins retained ligand binding and signal transduction but with adversely affected affinities and signal amplitudes for the thiolated, but not the biotinylated, proteins. We also immobilized these proteins in a more specifically oriented layer to maleimide‐derivatized plates using a His2Cys2 zinc finger domain fused at either their N or C termini. Proteins immobilized this way either retained, or displayed enhanced, ligand affinity and signal amplitude. In all cases tested ligand binding by immobilized proteins is reversible, as demonstrated by several iterations of ligand loading and elution. The kinetics of ligand exchange with the immobilized proteins are on the order of seconds.
High throughput comparative genomic hybridization array analysis of multifocal urothelial cancers
Authors: Kawanishi Hiroaki , Takahashi Takeshi , Ito Masaaki , Watanabe Jun , Higashi Shin , Kamoto Toshiyuki , Habuchi Tomonori , Kadowaki Tadashi , Tsujimoto Gozoh , Nishiyama Hiroyuki , Ogawa Osamu
Published: July 2006

The purpose of this study was to examine genetic alterations occur during synchronous or metachronous multifocal development of urothelial cancers on the whole genome using a comparative genomic hybridization (CGH) array. We used 10 tumor pairs (2 tumors for each patient), in which we had previously defined a clonal relationship by microsatellite analysis. For CGH array analysis, Vysis GenoSensor Array 300 kit was used. An unsupervised hierarchical cluster analysis revealed that the tumors from one patient were clustered together independent of the tumors of all other patients. On the other hand, many genetic divergences among multifocal urothelial cancers were newly found by a CGH array analysis. The concordant genetic alteration patterns of the chromosomal arm in tumor pairs were most frequently observed in 9p, 9q, 8p, 7p, 7q and 11q, while discordant patterns were most frequently found in 15q, 20q, 2q, 10p and 11q. Investigation using a CGH array showed that genetically stable multifocal tumors were less frequent, and that a large percentage of urothelial cancers accumulate genetic alterations during multifocal development by clonal evolution. We might have to consider these genetic accumulations during multifocal development when designing strategies for prevention and detection of recurrent multifocal urothelial cancers. CGH array can be a powerful tool for genetic analysis of multifocal urothelial cancer. (Cancer Sci 2006; 97: 746–752)
Different versions of Pseudomonas syringae pv. tomato DC3000 exist due to the activity of an effector transposon
Authors: LANDGRAF ANGELIKA , WEINGART HELGE , TSIAMIS GEORGE , BOCH JENS
Published: July 2006

The plant pathogenic bacterium Pseudomonas syringae pv. tomato strain DC3000 is a key model organism to study plant–pathogen interactions. We realized that two versions of this strain, which carry plasmids of different sizes, exist in our strain collections. The difference was located to a 9.4‐kb deletion within the larger of the two endogenous plasmids encompassing the partitioning genes parA and parB and a putative mobile element encoding the type III effector hopAM1‐2 (formerly avrPpiB2). Both plasmid variants are lost in similar frequency, indicating that the partitioning genes are not essential for stability of the plasmid. In addition, the deletion derivative strain DC3001 exhibited the same virulence towards Arabidopsis as strain DC3000. The deletion site in DC3001 is located immediately adjacent to a putative transposon that carries the effector hopX1 (formerly avrPphE), suggesting that the deletion originated from an aberrant transposition event of this element. By tagging the hopX1 transposon with an antibiotic resistance cassette on a suicide plasmid it was shown that the element is functional and produces a target site duplication of 5 bp. The plasmid also integrated into the chromosome in several cases, possibly mediated by one‐ended transposition of the hopX1 transposon. This is the first report that describes an active effector‐transposon. Comparison of DC3000 strains from several sources revealed that strains exist with differences in the endogenous plasmid composition.
The small mammal community of Mukogodo Forest, Kenya
Authors: Webala Paul W. , Muriuki George , Lala Fredrick , Bett Alice
Published: July 2006

Species richness and diversity of rodents and insectivores were investigated at relict forest patches of Mukogodo, Laikipia, Kenya using Sherman's live traps and pitfall traps. Two hundred and nineteen individuals were captured in 3021 trap‐nights. There were eleven species in two taxonomic groups, Rodentia and Insectivora. Two other rodent species were sighted but not captured. Thirteen bats belonging to four species (Epomophorous wahlbergi, Pipistrellus kuhlii, Scotophilus dingani and Nycteris thebaica) were opportunistically trapped using mist nets. Two of the four species accumulation curves for forest patches did not reach an asymptote. Species richness and diversity were highest at Kurikuri compared with other patches because of habitat variability. The results support the prediction that forest disturbance and degradation lead to an increase in generalist species as compared with specialists and highlight the importance of relict afromontane forests in the conservation of small mammals in Kenya.
Changes in a Sudano‐Sahelian rodent community after slash‐and‐burn farming (Gonsé Forest, Burkina Faso)
Authors: Papillon Y. , Godron M. , Delattre P.
Published: July 2006

This study describes the recolonization by a Sudano‐Sahelian rodent community of an area slashed and burned in the middle of the dry season (Gonsé Forest in Burkina Faso). A series of abundance cycles occurred. The first began with the wet season and the arrival of a succession of four species: Taterillus gracilis, Tatera guineae, Nannomys sp. and Mastomys erythroleucus. Taterillus gracilis appeared to be the least demanding species. It was sexually active whatever the season and took advantage of reduced competition among species on the burned tracts. Tatera guineae also extended its spatial distribution but failed to reproduce. Nannomys sp. rapidly increased after the first rains. Although generally held to be the most prolific and opportunistic of the species involved, M. erythroleucus only found conditions amenable to its colonization late on. The timing of the disruption and whether or not it coincides with the reproductive period and the mobility phase of each species are decisive factors. This information is useful for a clearer understanding of the dynamics of each species and for evaluating the risk and probable locations of outbreaks of certain species.
Effect of voriconazole on the pharmacokinetics and pharmacodynamics of zolpidem in healthy subjects
Authors: Saari Teijo I. , Laine Kari , Leino Kari , Valtonen Mika , Neuvonen Pertti J. , Olkkola Klaus T.
Published: July 2006

Aims

To assess the effect of voriconazole on the pharmacokinetics and pharmacodynamics of zolpidem.

Methods

In a randomized cross‐over study with two phases, 10 healthy subjects ingested 10 mg of zolpidem with or without oral voriconazole pretreatment. The concentrations of zolpidem were measured in plasma up to 24 h and pharmacodynamic variables were monitored for 12 h.

Results

Voriconazole increased the peak plasma concentration of zolpidem by 1.23‐fold [P < 0.05; 90% confidence interval (CI) 1.05, 1.45] and the area under the plasma zolpidem concentration–time curve by 1.48‐fold (P < 0.001; 90% CI 1.29, 1.74). The time to peak plasma zolpidem concentration was unchanged by voriconazole but the half‐life was prolonged from 3.2 to 4.1 h (P < 0.01; 95% CI on the difference 0.27, 1.45). The pharmacodynamics of zolpidem were unaffected by voriconazole.

Conclusion

Voriconazole caused a moderate increase in exposure to zolpidem in healthy young subjects but no clear pharmacodynamic changes were observed between the groups.
Using the output from global circulation models to predict changes in the distribution and abundance of cereal aphids in Canada: a mechanistic modeling approach
Authors: NEWMAN JONATHAN A.
Published: July 2006

Climate change will alter the abundance and distribution of species. Predicting these shifts is a challenge for ecologists and essential information for the formation of public policy. Here, I use a mechanistic mathematical model of the interaction between grass growth physiology and aphid population dynamics, coupled with the climate change projections from the UK's Hadley Centre HadCM3 global circulation model (GCM) and Canada's Center for Climate Modeling and Analysis CGCM2 GCM to predict the changes in the abundance and distribution of summer cereal aphid populations in wheat‐growing regions of Canada. When used with the HadCM3 projections, the model predicts a latitudinal shift northward in abundances but there is longitudinal variation as well. However, when used with the CGCM2 projections the model predicts that continental regions will see a decline while coastal regions will see an increase in summer cereal aphid populations. These effects are stronger under the higher emissions scenarios.
Ultrasonographic guidance in pediatric regional anesthesia part 1: theoretical background
Authors: MARHOFER PETER , FRICKEY NATHALIE
Published: July 2006

Recent findings support the use of ultrasonographic guidance in pediatric regional anesthesia. This review article illustrates basic knowledge in physics of ultrasound and ultrasonographic appearance of neuronal structures, which are prerequisites for the safe application of this technique in daily clinical practice. A critical view on education and ethics in science should emphasize future developments in ultrasonography for pediatric regional anesthesia.
Migration Regions and Population Redistribution
Authors: MORRILL RICHARD L.
Published: July 2006

Cross and net migration flows among the states for 1975‐80 were used to define migration regions, or groups of states with similar patterns of net interchange. This typology may be characterized as a transition from a northeastern “core” which lost to all other regions to a northwestern “periphery” which gained from all other regions. Florida and California were found to have an important role in redistributing population. The typology was also valid for all age groups and across racial and ethnic categories. The typology remained meaningful when the 1975‐80 data were compared to 1965‐70 and 1980‐85 data, despite great volatility in net migration and significant change in the placement of many states.
Dynamic Shift‐Share Analysis
Authors: BARFF RICHARD A. , III PRENTICE L. KNIGHT
Published: July 2006

Most applications of shift‐share analysis to regional employment change have used a study period of several years and have examined conditions only at the beginning and end years. This comparative static approach does not take into account the continuous changes in both industrial mix and size of total employment of the region over the study period. Calculating the national growth effect, the industrial mix effect, and the competitive effect on an annual basis and then summing the results over the study period provides a more accurate allocation of job changes among the three shift‐share effects. This approach, which we term dynamic shift‐share analysis, also allows unusual years and years of economic transition to he identified. We illustrate the use of dynamic shift‐share by presenting results of an analysis of New England employment growth from 1939 to 1984, using U.S. Bureau of Labor Statistics data. The use of the dynamic form of shift‐share is important when the study period is characterized by either large changes in regional industrial mix or major differences between regional and national growth rates.
The Changing Regional Structure of the U.S. Economy
Authors: CONNAUGHTON JOHN E. , MADSEN RONALD A.
Published: July 2006

This paper utilizes newly available industry‐specific historical measures of Gross Regional Product to highlight the changing regional structure of the U.S. economy between 1963 and 1986. During this period, the percentage of U.S. output produced in the eight different regions changed significantly. The largest changes occurred in the Great Lakes (−3.65 percent), Mideast (−3.32 percent), and Southeast (+3.64 percent).

Four major industry sectors (Agriculture, Mining, Construction, and Government) declined in relative importance in all eight regions. Five major industry sectors (TCPU, Retail Trade, Wholesale Trade, FIRE, and Services) expanded in relative importance. Somewhat surprisingly, Manufacturing output expanded for the U.S. as a whole and for six of the eight regions. The perception of decline in the relative importance of manufacturing in the U.S. is clearly based on the dramatic declines in the once dominant manufacturing base of the Mideast and Great Lakes regions.
Government Policy and the Export Performance of the Mexican Automobile Industry
Authors: TRUETT DALE B. , TRUETT LILA J.
Published: July 2006

ABSTRACT This paper presents a historical perspective of growth of the Mexican automobile industry, focusing on the changing position of Third‐World producers within the global motor vehicle industry. Both the impact of Mexican government policies directed toward increasing international competitiveness and that of adjustments made by transnational corporations to changes in technology and production methods are reviewed. Finally, a demand function that relates the proportion of the industry output that is exported to relative producer prices, Mexican and U.S. income, and government policy variables is estimated. The results of that analysis are consistent with the hypotheses that Mexican automotive sector exports are significantly related to (1) relative Mexico/U.S. producer prices, (2) income in the United States, and (3) changes in Mexican government export promotion policies initiated in 1983. These specific results, coupled with the global changes taking place in the industry, lead to the conclusion that Mexico can be expected to continue on its course toward fuller integration into the world motor vehicle industry as a producer of both finished vehicles and parts. While this would be a probable scenario even in the absence of the North American Free Trade Agreement, the Agreement is likely to accelerate the growth of internationally competitive automotive sector production in Mexico.
Production System Changes in the Korean Consumer Electronics Sector
Authors: CHOO SUNGJAE
Published: July 2006

This paper establishes the concept of production system as an analytical framework to embrace recent industrial changes. Five dimensions of production system changes are posited. A case study of the Korean consumer electronics sector shows that the companies have experienced diverse patterns of changes, but these changes are generally related to plant location, ownership, export orientation, and company size.
Conserving Biological Diversity and the Conservation Reserve Program
Authors: SZENTANDRASI SUSANNE , POLASKY STEPHEN , BERRENS ROBERT , LEONARD JEROME
Published: July 2006

ABSTRACT The lack of success with the endangered species approach to conserving biodiversity has led to calls for programs that are designed to maintain viable populations of species before they become endangered. While wildlife preserves are an important component of biodiversity conservation, effective protection of species will often take place on land that is used primarily for purposes other than wildlife habitat. The suitability of these lands as wildlife habitat can be influenced by government programs. An important example of a program affecting agricultural land use is the Conservation Reserve Program (CRP), which is the largest land retirement program in US. history. The expected down‐sizing of the program in the mid 90s sharpens the need for improved targeting if the program is to continue to provide wildlife benefits. This paper studies how well the current CRP fares as a biodiversity conservation program and suggests possible ways to target the CRP to conserve wildlife habitat. A methodology for tackling this task in Oregon is outlined.
Cross‐border Small‐scale Trading in South‐Eastern Europe: Do Embeddedness and Social Capital Explain Enough?
Authors: EGBERT HENRIK
Published: July 2006

The article analyses cross‐border small‐scale trading (CBST) from the perspective of New Institutional Economics. It offers an alternative analytical starting point to this topic, which is mainly tackled by sociologists and anthropologists. It is argued that concepts like social capital or social embeddedness can be of certain analytical use but that they hardly suffice to explain human behaviour in a detailed manner. The case of reference is the institution of bribery as it evolved in the first half of the 1990s at the Bulgarian‐Turkish border.
Single-Neuron Activity and Imaging during Epileptogenesis: What can be Seen and how Best to see It?
Authors: Dudek F. Edward
Published: July 2006

Evolving into Epilepsy: Multiscale Electrophysiological Analysis and Imaging in an Animal Model

Sanchez JC, Mareci TH, Norman WM, Principe JC, Ditto WL, Carney PR

Exp Neurol 2006;198(1):31–47

Epilepsy research for the design of seizure detection/prediction neuroprosthetics has been faced with the search for electrophysiologic control parameters that can be used to infer the epileptic state of the animal and be leveraged at a later time to deliver neurotherapeutic feedback. The analysis presented here uses multi-microelectrode array technology to provide an electrophysiologic quantification of a hippocampal neural ensemble during the latent period of epileptogenesis. Through the use of signal processing system identification methodologies, we were able to assess the spatial and temporal interrelations of ensembles of hippocampal neurons and relate them to the evolution of the epileptic condition. High-field magnetic resonance (MR) imaging was used to determine the location of electrode placement and to evaluate hippocampal pyramidal cell structural damage. Long-term single unit activity analysis suggests that hippocampal neurons in both CA1–2 and dentate regions increase the number of occurrences and duration of their bursting activity after injury to the contra-lateral hippocampus. The trends inferred from both single neuron and ensemble analysis suggests that the evolution into epilepsy is not abrupt but modulates gradually from the time of injury.
Hyaluronidase activity in gingival crevicular material and in peritoneal exudate leukocytes in dogs
Authors: Tynelius‐Bratthall Gunilla
Published: July 2006

Hyaluronidase activity has been studied in gingival crevicular material from clinically healthy and chronically inflamed gingivae, and in neutrophil polymorphonuclear leukocytes (neutrophils) from peritoneal exudates. Activity was demonstrated by determining the release of N‐acetyl‐glucosamine from purified hyaluronic acid. Hyaluronidase activity was found in gingival crevicular material within the pH range. 3‐7. with pH optima at 3.7 and 6.0. Material from inflamed gingivae showed greater enzyme activity than that from healthy gingivae. Hyaluronidase activity was present in homogenates of neutrophils from peritoneal exudates with a pH optimum of 3.7. Little enzyme activity was found above pH 5.0. This suggests that the hyaluronidase activity at pH 3.7 in gingival crevicular material might originate from neutrophils in the gingival crevice.
Microspectrophotometric analysis of succinic dehydrogenase and glucose‐6‐phosphate dehydrogenase in human oral epithelium
Authors: Itoiz M. E. , Carranza F. A. , Giménez I. B. , Cabrini R. L.
Published: July 2006

The distribution of succinic dehydrogenase and glucose‐6‐phosphate dehydrogenase in human gingival epithelium was studied using a unidirectional scanning method of microspectrophotometric evaluation. The quantitative analysis was directed to obtain information on the mean enzymatic content of gingival epithelium in different areas and localization of layers of different enzymatic concentration within each epithelial area explored.

Glucose‐6‐phosphate dehydrogenase had its maximum content in epithelium of marginal gingiva and lower contents in oral mucosa epithelium, crevicular epithelium and epithelial attachment.

uccinic dehydrogenase content was greater in attached gingiva than in all other zones. Glucose‐6‐phosphate dehydrogenase increased its concentration from the basal to the superficial layers in attached and marginal gingiva, remained stable in all strata of oral mucosal epithelium and crevicular epithelium and reduced its activity towards the surface in epithelial attachment. Succinic dehydrogenase decreased its concentration from the basal to the superficial layers in all zones.
The Value of State Ground‐Water Agencies to the Small Water Well Contractor
Authors: Walker A. C.
Published: July 2006

It is the State's responsibility to see that its ground‐water resources are developed with as little “red tape” as possible.

The well driller's responsibility is to his customers.

Both State ground‐water agencies and water well drillers can carry out their responsibilities best by working together. Such cooperation can eliminate unnecessary drilling regulations and result in better wells through exchange of information.

In many instances, overdevelopment or contamination of an aquifer could have been avoided if drillers and States had worked together, rather than in opposite directions.
Artificial Recharge and pollution of Ground Water
Authors: Harmeson Robert H. , Vogel Orville W.
Published: July 2006

In an attempt at partially counteracting the serious depletion of ground‐water resources at Peoria, Illinois, a method for artificial replenishment has been developed by the Illinois State Water Survey and used in two well fields. Water taken from the Illinois River is chlorinated and infiltrated into the ground‐water aquifers by means of recharge pits.

Potential pollutants of physical, chemical, bacterial, and radioactive nature are present in the river at all times in varying degrees. Possible pollution of the ground water is patently inherent to the artificial recharge process.

Eight years of operating experience have proven the pit method of recharge to be effective in the Peoria area. Substantial quantities of water are recharged annually and existing standards for quality have been met. The results serve to point out problems which are encountered; to emphasize the need for control measures; and to establish trends and effects which may become important in the future.
Bacteriological and Chemical Factors in Induced Infiltration
Authors: Klaer Fred H.
Published: July 2006

The lowering of ground‐water levels by pumping from Horizontal or vertical wells near a surface stream may cause water to move from the stream into the water‐bearing materials by the process known as induced infiltration. In such cases, the natural deposits of sand and gravel serve as large natural filter beds effectively removing or reducing turbidity, organic matter and pathogenic bacteria. This paper discusses the general processes by which such removal is accomplished as well as the significance of certain changes in chemical characteristics of the water as it passes from a surface source to an underground point of collection. By a better understanding of the processes involved, the bacteriological and chemical quantities of infiltrated water supplies can be improved.
Large Diameter Hole Drillinga
Authors: Lauman R. H.
Published: July 2006

The construction features of large diameter wells drilled mostly on Long Island, measuring 24 to 42 inches in diameter, and ranging from 100 to 1,000 feet deep with capacities up to 3,000 gpm are described.
Microtime Measurements of Ground‐Water Level Fluctuations
Authors: Walton W. C.
Published: July 2006

Water‐level measurements made during the early seconds and minutes of aquifer tests may often be used to determine the hydraulic properties of an aquifer and to locate hydrogeologic boundaries. This paper describes a method, using a modified stylus carriage and pen and a stop watch, of recording microtime water‐level measurements in a well equipped with a recording gage. Ordinary and micro‐time records of water‐level fluctuations are simultaneously obtained. Microtime water‐level measurements often aid in appraising the effects of slow gravity drainage under water‐table conditions and anisotropic and heterogeneous conditions.
Statutes and Regulations Governing Private Water Well Construction and Pump Installationsa
Authors: Calabresa T. A.
Published: July 2006

The intent of this paper is to discuss the need for laws and regulations governing construction of wells for private water supplies. This will include: (1) why laws and regulations are necessary, (2) need for registration and licensing of drillers and pump installers, (3) how laws and regulations affect uniformity of construction and the desirability of such uniformity, (4) how they encourage the manufacture of new materials and group organization, (5) what a law and code should contain, (6) need of judgment in administering laws and the regulations adopted pursuant thereto, and (7) the difficulties in enforcing laws and regulations including budgetary reasons. The material presented is drawn from Wisconsin's 26 years of private water supply administration and in part from personal experience. Hence, all statements and conclusions made do not necessarily represent the thinking, views or practice of the author's employer.
The Power Auger in Ground‐Water Exploration in Ohio
Authors: Bailey Norman G.
Published: July 2006

The power auger is a useful tool in the fields of ground‐water geology and hydrology. The Ohio Division of Water has had excellent success in utilizing this type of equipment during the past seven years. Augering is an economical and effective method of drilling test holes in unconsolidated deposits provided the tool is used within its limitations and where it works best. The augering method is particularly useful to the ground‐water investigator exploring sand and gravel aquifers or buried bedrock valleys, installing drive points, and making seismic refraction surveys.
Television — A New Tool for the Ground‐Water Geologista
Authors: Callahan J. T. , Wait R. L. , McCollum M. J.
Published: July 2006

The television camera has become a tool of the ground‐water geologist, enabling him to examine visually the inside of a well deep below the land surface. Using the camera, the rocks can be viewed in place. Of great importance to the ground‐water studies in coastal Georgia, the camera enables the geologist to see the important water‐bearing zones in a limestone aquifer, and to recognize cracks and solution cavities, the changes in geologic formations, and the irregularities in the well bore that indicate the relative hardness of the rocks. The engineer, well driller, and water developer can examine a well when “trouble shooting” to see whether the casing is broken, whether screens are eroded, or whether the well contains obstructions.
Recharge Rates of Principal Aquifers in Lake County, Indianaa
Authors: Rosenshein J. S.
Published: July 2006

The upper 350 to 400 feet of rocks underlying Lake County, Indiana, form a single but complex hydrologic system. The rock units composing this system consist (in ascending order) of dolomite, clay till (unit 4), glaciofluvial sand (unit 3), clay till (unit 2), and lacustrine sand, silt, and clay (unit 1). The dolomite and unit 3 form the principal aquifers and the clay tills, units 4 and 2, the confining layers.

The geohydrology of the confining layers controls to a large extent the rate at which the aquifers are recharged from local precipitation and, thereby, their potential yield. Unit 4, the dolomite's confining layer, has an estimated average vertical permeability of about 0.003 gpd (gallon per day) per square foot. Under present conditions of head difference, the rate of recharge to the dolomite through unit 4 is estimated to average 20,000 gpd per square mile. Unit 2, the confining layer for unit 3, has an average estimated vertical permeability of about 0.007 gpd per square foot. Under present conditions of head difference the recharge through unit 3's confining layer is estimated to average about 100,000 gpd per square mile. However, these rates of recharge can be expected to increase as the head difference across each confining layer increases with extensive development of the aquifer.
Is Your “Water Bank Account” Top Heavy with Capital?
Authors: Vaseen V. A.
Published: July 2006

Lakes and ponds are “stored” waters or a water bank “principal,” the interest being the diffused surface waters, underground waters, and natural streams or water courses depositing in the “storage.” The natural use of “surface water” or waters able to be seen, has been for the most part the major concern of water bankers, but the time has come to put the “vault storage” into circulation and make it a part of the “money flow.”

Ground water can be removed for use in amounts depending in part on the quantity of water in the underground storage reservoir. A ground‐water reservoir must be “drawn down” to cause its greatest efficiency. The rate of depletion of the various natural resources makes it mandatory that we use our “water bank account capital” where such use can provide benefits to mankind not otherwise available, where such “capital” depletion is over a sufficiently long period to allow adjustment prior to complete depletion, and where the cost of capital for such use can be amortized over an acceptable period of time.
Hydrologic Factors Pertinent to Ground‐Water Contaminationa
Authors: Brown R. H.
Published: July 2006

Predictions of where and how a fluid waste may travel from disposal site to the water table require detailed information on the physical characteristics, location, and extent of all pervious and impervious materials in the unsaturated zone. Principles concerning the flow system in the unsaturated zone indicate the importance of choice of disposal technique in predicting the time required for the fluid waste to traverse the distance to the water table. With appropriate data on the location, extent, and physical properties of water‐bearing materials and on the boundaries of the saturated zone flow system, it is possible to analyze the relative merits of a variety of waste disposal techniques and to describe the probable consequences of each. Environments of consolidated rocks, such as granites, sandstones, and limestones, pose problems in addition to those related to unconsolidated or granular porous media in defining the fluid‐flow regimes that involve joint patterns, fracture patterns, solutional openings, and the rock structure.

The consequences of ground‐water contamination can be just as damaging to water users as the pollution of surface streams. In fact it can be argued that the consequences are far more damaging because they persist over much longer periods of time after the contaminating source has been eliminated. It would appear prudent, therefore, to guard against contamination of the ground‐water resource in the first instance, rather than to engage in long expensive rehabilitation measures after the damage has been done.

In 1960 Graham Walton presented data concerning contamination, by sewage or other man‐made wastes, of surface and underground waters. The circumstances attending the reported incidents of contamination, especially those involving ground‐water supplies, have aided materially in the choice of a few principles and ideas that will identify the role of some significant hydrologic factors in the underground movement of fluid wastes.

Walton's discussion of ground‐water contamination refers often to physical settings into which fluid wastes are discharged at or near the land surface into cesspools, tile‐drain fields, and holding ponds. Furthermore, most reported instances of ground‐water contamination have taken place in relatively humid