cssi/SciSciGPT-SciSciNet huggingface dataset:
Effects of central cholinergic blockade on striatal dopamine release measured with positron emission tomography in normal human subjects

Abstract Previously we demonstrated that positron emission tomography (PET) can be used to measure changes in the concentrations of synaptic dopamine and acetylcholine. Whether induced directly or indirectly through interactions with other neurotransmitters, these studies support the use of PET for investigating the functional responsiveness of a specific neurotransmitter to a pharmacologic challenge. In an extension of these findings to the human brain, PET studies designed to measure the responsiveness of striatal dopamine release to central cholinergic blockade were conducted in normal male volunteers using high-resolution PET and [11C]raclopride, a D2-dopamine receptor antagonist. [11C]Raclopride scans were performed prior to and 30 min after systemic administration of the potent muscarinic cholinergic antagonist, scopolamine (0.007 mg/kg). After scopolamine administration, [11C]raclopride binding decreased in the striatum (specific binding) but not in the cerebellum (nonspecific binding) resulting in a significant decrease, exceeding the test/retest variability of this ligand (5%), in the ratio of the distribution volumes of the striatum to the cerebellum (17%). Furthermore, scopolamine administration did not alter the systemic rate of [11C]raclopride metabolism or the metabolite-corrected plasma input function. These results are consistent not only with the known inhibitory influence that acetylcholine exerts on striatal dopamine release but also with our initial 18F-labeled N-methylspiroperidol and benztropine studies. Thus these data support the use of PET for measuring the functional responsiveness of an endogenous neurotransmitter to an indirect pharmacologic challenge in the living human brain.
The relationship between student ratings of course effectiveness and student achievement

Summary For many years student ratings have been used to assess the strengths and weaknesses of various courses and the teaching abilities of the instructors involved. Investigators have either supported or attacked the validity of this assessment procedure on the basis of the direction and degree of the relationship found between student rating of a course and student achievement in that course. This validation study supplemented correlation analysis with analysis of variance to compare groups at various achievement levels and to control for the possible confounding effects of overall group analysis. Medical students responded to a Likert attitude scale about aspects of an anatomy course. The mean attitude scores for a high and a low course achievement group were significantly different at the 0.005 level; the high achievement group had a more positive course attitude.
Recovering Hicksian Consumer Surplus within a Collective Model: Hausman's Method for the Household

The purpose of this paper is to describe the implications of the collective model of household behavior for the methods used to estimate the economic value of non-marketed environmental resources. After demonstrating how the separability restrictions inherent in the collective model allow individual preference and household income allocation choices to be distinguished, the paper demonstrates how the framework can be used to recover Hicksian consumer surplus. An algebraic example is used to illustrate how the framework can be used in valuing environmental resources.
Charge transfer between semiconducting carbon nanotubes and their doped GaAs(110) and InAs(110) substrates detected by scanning tunnelling spectroscopy

Ultrahigh vacuum (UHV) scanning tunnelling microscopy (STM) and spectroscopy (STS) have been used to examine the role of substrate doping and composition in determining the electronic behaviour of semiconducting single-walled carbon nanotubes (SWNT) deposited onto III–V(110) surfaces. Hybrid SWNT/III–V(110) systems were created through sample cleavage and subsequent nanotube transfer in UHV. Room temperature STS spectra indicate electron transfer from the n-GaAs substrate to the supported SWNT and from the SWNT to the p-GaAs substrate, resulting in the respective n-type and p-type doping of the nanotube upon adsorption. STS measurements on InAs(110) supported carbon nanotubes are less uniform, with selected SWNTs on the n-InAs(110) surface exhibiting distinct electronic changes when shifted into registration with the substrate lattice. No such orientation sensitivity is detected in nanotubes on GaAs surfaces. The potential for systematic modification of a SWNT's electronic behaviour through intentional substrate engineering could present a new avenue for the design and fabrication of nanotube-based device structures.
Space stress and genome shock in developing plant cells

In the present paper I review symptoms of stress at the level of the nucleus in cells of plants grown in space under nonoptimized conditions. It remains to be disclosed to what extent gravity "unloading" in the space environment directly contributes to the low mitotic index and the chromosomal anomalies and damage that is frequently, but not invariably, demonstrable in space-grown plants. Evaluation of the available facts indicates that indirect effects play a major role and that there is a significant biological component to the susceptibility to stress damage equation as well. Much remains to be learned on how to provide strictly controlled, optimal environments for plant growth in space. Only after optimized controls become possible will one be able to attribute any observed space effects to lowered gravity or to other significant but more indirect effects of the space environment.
Laparoscopic mesh explantation and drainage of sacral abscess remote from transvaginal excision of exposed sacral colpopexy mesh

Sacral colpopexy may be complicated by mesh exposure, and the surgical treatment of mesh exposure typically results in minor postoperative morbidity and few delayed complications. A 75-year-old woman presented 7 years after a laparoscopic sacral colpopexy, with Mersilene mesh, with an apical mesh exposure. She underwent an uncomplicated transvaginal excision and was asymptomatic until 8 months later when she presented with vaginal drainage and a sacral abscess. This was successfully treated with laparoscopic enterolysis, drainage of the abscess, and explantation of the remaining mesh. Incomplete excision of exposed colpopexy mesh can lead to ascending infection and sacral abscess. Laparoscopic drainage and mesh removal may be considered in these patients.
A route to enantiopure RNA precursors from nearly racemic starting materials

The single-handedness of biological molecules is critical for molecular recognition and replication processes and would seem to be a prerequisite for the origin of life. A drawback of recently reported synthetic routes to RNA is the requirement for enantioenriched reactants, which fails to address the puzzle of how the single chirality of biological molecules arose. Here, we report the synthesis of highly enantioenriched RNA precursor molecules from racemic starting materials, with the molecular asymmetry derived solely from a small initial imbalance of the amino-acid enantiomers present in the reaction mixture. Acting as spectators to the main reaction chemistry, the amino acids orchestrate a sequence of physical and chemical amplification processes. The emergence of molecules of single chirality from complex, multi-component mixtures supports the robustness of this synthesis process under potential prebiotic conditions and provides a plausible explanation for the single-handedness of biological molecules before the emergence of self-replicating informational polymers.
Newly diagnosed type 2 diabetes mellitus.

A 62 year old woman has returned to you for the results of blood tests. She had attended for a well woman check up two weeks earlier and had mentioned that she was experiencing persistent fatigue. A random plasma glucose test that day showed a glucose concentration of 11.4 mmol/l, so you had arranged for her to have a fasting blood glucose test. Her fasting blood glucose was 8.5 mmol/l. She has no history of vascular disease or other serious medical conditions. Her aunt had diet controlled diabetes and died of a cerebrovascular event at the age of 68. Initial management of newly diagnosed type 2 diabetes Diagnosis -You can make a diagnosis on the basis of …
Simulation of volume polarization for the influence of solvation on chemical shielding

The effect of bulk dielectric solvation on chemical shielding at nitrogen in CH3CN is studied with reaction field theory. A previous work has demonstrated the strong influence on this property from volume polarization, which describes that part of the reaction field arising from solute charge density penetrating outside its cavity. The essentially exact treatment of volume polarization used in that work is computationally demanding, and a more facile method for simulation of the volume polarization has recently been proposed. It is found in the present work that this simulation of the volume polarization yields results in excellent agreement with the essentially exact treatment of the strong volume polarization effects on nitrogen shielding in CH3CN.
α2-agonist binding sites in brain: [125I]Para-iodoclonidine versus [3H]para-aminoclonidine

The localization of alpha 2-receptors was determined by quantitative autoradiography using [125I]para-iodoclonidine ([125I]PIC) and [3H]para-aminoclonidine ([3H]PAC). In cortical tissue, [125I]PIC and [3H]PAC were equipotent in their capacity to bind sites recognized by oxymetazoline (preferentially binds to the alpha 2A receptor subtype). The iodinated ligand was about 10 times more potent than [3H]PAC for binding to the heterogenous receptor population labeled by ARC-239 (alpha 2B and alpha 2C). The density of [125I]PIC binding was found to be two-fold higher than that of [3H]PAC in many brain areas and the disparity was even greater in regions such as the dentate gyrus, stria terminalis, and granular layer of the cerebellum. By contrast, other regions of the brain such as the laterodorsal thalamic nucleus, the locus coeruleus, and several amygdaloid areas had equivalent levels of binding. These observations indicate that [3H]PAC has selectivity for the alpha 2A receptor subtype and thus offer a restricted view of alpha 2-adrenergic receptor distribution. The iodinated ligand provides a more complete picture of the overall alpha 2 receptor population.
Boric acid binding studies with diol containing polyethylenimines as determined by 11B NMR spectroscopy

Three water-soluble polymers incorporating increasing levels of 2,3-dihydroxy propyl attached to polyethylenimine (PEI) backbone were synthesized, characterized by NMR, and investigated for their ability to bind boric acid (BA). 11B NMR spectroscopy showed that BA interacted with the polymeric 2,3-dihydroxy propyls by forming borate monoester and borate diesters in the boron concentration range of 100–1000 ppm and at 0.0775M polymer. Borate monoester species predominated for low functionalization levels (33% of the PEI amines functionalized), whereas borate diester species dominated for the higher functionalized polymers (66–100% of the PEI amines functionalized). All three polymers showed that 100% of the BA was bound as a mixture of borate mono- and diesters at 100-ppm boron. The overall best performer based on total borate ester formation was the 2/3-PEI, with a binding Kd of 631 at 200 ppm boron. Borate ion concentration was measured from the 11B NMR chemical shift of the BA/borate peak and it decreased as 1/3-PEI > 2/3-PEI > 3/3-PEI. Variable temperature 11B NMR showed drastic reduction of borate ester species at 65°C. Thus, PEI polymers, as the ones investigated in this work, are reasonable candidates for the selective recovery and recycle of BA. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4411–4418, 2006
The effect of environmental stress on the relationship of heterozygosity to growth rate in the coot clam Mulinia lateralis (Say)

Abstract The relationship between allozyme heterozygosity and growth was examined under four environmental conditions in Mulinia lateralis (Say). We demonstrate a significant genotype by environment interaction: the enhancement of heterozygote growth advantage under conditions of environmental (energetic) stress. Since the energetic advantage of multiple-locus heterozygosity is metabolically derived, we conclude that the different performances (e.g., growth) between heterozygous vs. homozygous individuals is both less apparent and less adaptively important in environments that minimize energy demands on metabolism.
The formation of gluconyl peptides during the heating of amino acids and glucose in alkaline buffer solutions.

Abstract Gluconyl glycine, gluconyl- l -leucine, and gluconyl- d -glutamic acid were synthesized and compared chromatographically to the extra unknown compounds isolated from mixtures of amino acids autoclaved with glucose in alkaline solutions. These investigations strongly indicate that gluconyl peptide linkages are formed between amino compounds and glucose under these conditions. In vitro studies on the digestibility of the synthesized gluconyl peptides by pancreatin and carboxypeptidase further substantiate the view previously proposed that the decreased nutritive value which is observed when proteins are autoclaved in the presence of sugars is the result of the formation of atypical linkages resistant to the action of digestive enzymes.
Bond Line Thickness of Thermal Interface Materials With Carbon Nanotubes

Increasing power dissipation in today’s microprocessors demands thermal interface materials (TIMs) with lower thermal resistances. The TIM thermal resistance depends on the TIM thermal conductivity and the bond line thickness (BLT). Carbon Nanotubes (CNTs) have been proposed to improve the TIM thermal conductivity. However, the rheological properties of TIMs with CNT inclusions are not well understood. In this paper, the transient behavior of the BLT of the TIMs with CNT inclusions has been measured under controlled attachment pressures. The experimental results show that the impact of CNT inclusions on the BLT at low volume fractions (up to 2 vol%) is small; however, higher volume fraction of CNT inclusions (5 vol%) can cause huge increase in TIM thickness. Although thermal conductivities are higher for higher CNT fractions, a minimum TIM resistance exists at some optimum CNT fraction for a given attachment pressure.Copyright © 2005 by ASME
Similarities in protein synthesis and degradation in normal and dystrophic muscle cultures.

Abstract Protein synthesis and degradation were compared in cultured muscle cells obtained from normal and dystrophic chick embryos under conditions where labeled amino acid reincorporation was not a complicating factor, where fibroblast contamination was minimized, and where the animals compared were as genetically similar as possible. Under these conditions both cell types exhibited a half-time of protein turnover of 34 h. Degradation in both was inhibited 21% by leupeptin (50 μg/ml), and both showed parallel increases in degradation rates under ‘step-down’ conditions.
X13CMS: Global Tracking of Isotopic Labels in Untargeted Metabolomics

Studies of isotopically labeled compounds have been fundamental to understanding metabolic pathways and fluxes. They have traditionally, however, been used in conjunction with targeted analyses that identify and quantify a limited number of labeled downstream metabolites. Here we describe an alternative workflow that leverages recent advances in untargeted metabolomic technologies to track the fates of isotopically labeled metabolites in a global, unbiased manner. This untargeted approach can be applied to discover novel biochemical pathways and characterize changes in the fates of labeled metabolites as a function of altered biological conditions such as disease. To facilitate the data analysis, we introduce X13CMS, an extension of the widely used mass spectrometry-based metabolomic software package XCMS. X13CMS uses the XCMS platform to detect metabolite peaks and perform retention-time alignment in liquid chromatography/mass spectrometry (LC/MS) data. With the use of the XCMS output, the program then i...
The effects of morphine-like compounds on the light responses of the brine shrimp Artemia salina.

Methods for the measurement of the light responses of Artemia nauplii and adults are described. Although no effects of levorphanol were found on the positive phototaxis of nauplii, this compound inhibited and partially reversed the negative phototaxis of adults. Levorphanol was also effective in adults after removal of the compound eyes, indicating that it probably acts on the median eye or its central connections in adults.
Anterior corpectomy via the mini-open, extreme lateral, transpsoas approach combined with short-segment posterior fixation for single-level traumatic lumbar burst fractures: analysis of health-related quality of life outcomes and patient satisfaction.

OBJECT The authors present clinical outcome data and satisfaction of patients who underwent minimally invasive vertebral body corpectomy and cage placement via a mini-open, extreme lateral, transpsoas approach and posterior short-segment instrumentation for lumbar burst fractures. METHODS Patients with unstable lumbar burst fractures who underwent corpectomy and anterior column reconstruction via a mini-open, extreme lateral, transpsoas approach with short-segment posterior fixation were reviewed retrospectively. Demographic information, operative parameters, perioperative radiographic measurements, and complications were analyzed. Patient-reported outcome instruments (Oswestry Disability Index [ODI], 12-Item Short Form Health Survey [SF-12]) and an anterior scar-specific patient satisfaction questionnaire were recorded at the latest follow-up. RESULTS Twelve patients (7 men, 5 women, average age 42 years, range 22–68 years) met the inclusion criteria. Lumbar corpectomies with anterior column support were...
An earthquake model with interacting asperities

SUMMARY A model is presented that treats an earthquake as the failure of asperities in a manner consistent with modern concepts of sliding friction. The mathematical description of the model includes results for elliptical and circular asperities, oblique tectonic slip, static and dynamic solutions for slip on the fault, stress intensity factors, strain energy and second-order moment tensor. The equations that control interaction of asperities are derived and solved both in a quasi-static tectonic mode when none of the asperities are in the process of failing and a dynamic failure mode when asperities are failing and sending out slip pulses that can trigger failure of additional asperities. The model produces moment rate functions for each asperity failure so that, given an appropriate Green function, the radiation of elastic waves is a straightforward calculation. The model explains an observed scaling relationship between repeat time and seismic moment for repeating seismic events and is consistent with the properties of pseudo-tachylites treated as fossil asperities. Properties of the model are explored with simulations of seismic activity that results when a section of the fault containing a spatial distribution of asperities is subjected to tectonic slip. The simulations show that the failure of a group of strongly interacting asperities satisfies the same scaling relationship as the failure of individual asperities, and that realistic distributions of asperities on a fault plane lead to seismic activity consistent with probability estimates for the interaction of asperities and predicted values of the Gutenberg–Richter a and b values. General features of the model are the exterior crack solution as a theoretical foundation, a heterogeneous state of stress and strength on the fault, dynamic effects controlled by propagating slip pulses and radiated elastic waves with a broad frequency band.
Transmission strategies for high-speed access over Category-7A copper wiring

This paper focuses on conceptual designs and demonstration of beyond 10G transmission systems for distribution of digital signals over standard Category-7A copper cable, which is an enhanced version of Category 7 cable. Although the actual implementation might not be feasible at the time of writing of this paper due to technology limitations and high production costs, we have been trying to address the technical feasibility, limitations and design of a system in a framework leading to a practical implementation in a not too distant future with the ever increasing speed of technology advances. We have demonstrated that a data rate up to 40Gbps over 100m of CAT-7A is feasible with reasonable complexity. Developing 100Gb/s over 100m balanced cabling is going to be very challenging. To optimize costs, while ensuring robust and reliable performance over 100 meters and through four connections, Category 8 cabling is the most likely choice to support the emerging IEEE 100GBASE-T application. The results of our investigations indicate that 100Gbps transmission is possible over 50m of such a cable.
The Ras signal transduction pathway

Considerable progress has been made over the past year in elucidating the mechanisms by which extracellular signals are transduced via cell surface receptors to trigger changes in gene expression which determine the growth and differentiated state of a cell. In particular, Ras proteins have been implicated as key intermediates that mediate the signal from upstream tyrosine kinases to a downstream cascade of serine/threonine kinases, which then activate nuclear factors that control gene expression and protein synthesis. How Ras proteins function is regulated in this role as a molecular switch, and how the signal is transmitted between the various components of the pathway, are now being determined. Finally, the Rho family of Ras-related proteins, which regulate the actin cytoskeleton, have also been implicated as mediators of oncogenic Ras transformation. The brisk pace at which the key components of Ras-mediated signal transduction pathways are being identified hold great promise that new targets for therapeutic intervention in cancer may now be identified.
Gene expression analysis on small numbers of invasive cells collected by chemotaxis from primary mammary tumors of the mouse

cDNA microarrays have the potential to identify the genes involved in invasion and metastasis. However, when used with whole tumor tissue, the results average the expression patterns of different cell types. We have combined chemotaxis-based cell collection of the invasive subpopulation of cells within the primary tumor with array-based gene expression analysis to identify the genes necessary for the process of carcinoma cell invasion. Invasive cells were collected from live primary tumors using microneedles containing chemotactic growth factors to mimic chemotactic signals thought to be present in the primary tumor. When used with mammary tumors of rats and mice, carcinoma cells and macrophages constitute the invasive cell population. Microbeads conjugated with monoclonal anti-CD11b (Mac-1α) antibodies were used to separate macrophages from carcinoma cells. We utilized PCR-based cDNA amplification from small number of cells and compared it to the quality and complexity of conventionally generated cDNA to determine if amplified cDNA could be used with fidelity for array analysis of this cell population. These techniques showed a very high level of correlation indicating that the PCR based amplification technique yields a cDNA population that resembles, with high fidelity, the original template population present in the small number of cells used to prepare the cDNA for use with the chip. The specific collection of invasive cells from a primary tumor and the analysis of gene expression in these cells are is now possible. By further comparing the gene expression patterns of cells collected by invasion into microneedles with that of carcinoma cells obtained from the whole primary tumor, the blood, and whole metastatic tumors, genes that contribute to the invasive process in carcinoma cells may be identified.
Food for thought ... on alternative methods for nanoparticle safety testing.

Nano is a big thing in toxicology. Articles, journals, and conferences are mushrooming, paralleling the rise of nanotechnologies but also showing the hunger of toxicology for new objects to study. Perhaps it would be better to focus on new approaches first? Nanomedicine promises new solutions for old problems, but what about the old problems of toxicology? It is a fallacy to assume that one can gain beneficial effects in the human organism without unwanted collateral effects. First, any biologically active agent perturbs physiology, hopefully as a corrective for the patient but at least requiring compensatory reactions of the healthy. Second, few agents are specific enough to have only one effect, but it is rare that we want all the effects and in the given mix of strengths. third, many agents show excess toxicity – even desired effects often become negative if excessively stimulated. this increase in negative effects is directly linked to more sensitive subpopulations (children, elderly, the diseased, those with genetic polymorphisms, etc.). thus, the promise of nanoparticles (NP) may be paid for in possible side-effects, i.e., toxicities (Garnett et al., 2006). For most manufactured NP, toxicity data are unavailable, with some exceptions for carbon black, titanium dioxide, iron oxides, and amorphous silica (Di Giacchino et al., 2009). So far nanoparticles and other nanomaterials (I will use the abbreviation NP for both but primarily thinking of particles or fibers and not e.g. nano-thick films) are, for the most part, treated by regulatory toxicology as chemicals (see last issue of this series, Hartung, 2010b). The most common definitions for NP include materials with dimensions from 1 nm (size of a sugar molecule) to 100 nm (size of a virus). Regulatory frameworks are on the way, opening up possibilities for alternative approaches (Sauer, 2009). Whether the differences between NP and their parent compounds are actually small or big problems, remains to be seen. But to quote Albert einstein: “Anyone who doesn’t take truth seriously in small matters cannot be trusted in large ones either.” When discussing alternative methods for nanoparticle toxicology, we might first look at some phrase permutations – leaving out one word in each iteration: – Alternative methods for toxicology – Methods for nanoparticle toxicology – Alternative nanoparticle toxicology – Alternative nano-methods Consideration 1: Alternative or advanced methods for toxicology?
Timing-Based Placement Considering Uncertainty Due to Process Variations

In the nanometer regime, the effects of variations are having an increasing impact on the delay, power, and yield characteristics of devices. In this paper, we propose the use of fuzzy and stochastic mathematical programming techniques for variation aware timing-based incremental placement. The uncertainty due to process variations in these techniques, are modeled using fuzzy numbers and probabilistic constraints, respectively. The objective is to minimize the critical path delay of the circuit in the presence of variations considering gate and interconnect delays. In the fuzzy approach, the average and worst case deterministic optimizations are performed to identify the bounds and convert the uncertain fuzzy problem into a crisp nonlinear problem. The stochastic optimization framework, on the other hand, transforms the probabilistic constraints into a second-order conic program (SOCP) with explicit mean and variance values. The fuzzy and stochastic approaches tested on ITC'99 benchmark circuits yielded around 12.60% and 10.53% improvements in timing, when compared to optimization with the worst case process variations setting.
Waveguide input method for time-domain wave propagation algorithms

A waveguide feed method is constructed for time-domain wave propagation algorithms. The concept is to connect a region of homogeneous index of refraction to the waveguide region by a refractive index taper. The first example of this method finds the coupling efficiency for a given input into a waveguide of a particular index geometry. The second example of this method reveals the evolution of the propagation constant through a horn geometry. >
Kinetic study of sulfide leaching by galvanic interaction between chalcopyrite, pyrite, and sphalerite in the presence of T. ferrooxidans(30°C) and a thermophilic microorganism (55°C)

A systematic, kinetic study and comparison of the leaching of mixed metal sulfides by galvanic conversion and in the presence of bacteria has been carried out for the first time using both powder (-100 to -400 mesh) and larger (bulk) specimen systems. The rates of dissolution of copper from chalcopyrite and zinc from sphalerite as single, electrically isolated (separate) systems were compared with electrically contacting (galvanically coupled) systems involving CuFeS(2)/FeS(2) and ZnS/FeS(2), with and without bacteria and at temperatures of 30 and 55 degrees C. The dissolution of Cu was observed to increase by a factor of 4.6 when the galvanic leaching of CuFeS(2)/FeS(2) was compared to CuFeS(2) leaching at 30 degrees C. When bacteria were present, Cu dissolution increased by an additional factor of 2.1 in the CuFeS(2)/FeS(2) system. At 55 degrees C, the corresponding ratios for Cu were 4.3 and 2.7, respectively. The galvanic leaching of Zn in the ZnS/FeS(2) system compared to ZnS leaching increased by a factor of 2 at 30 degrees C; in the presence of bacteria the dissolution of Zn from the ZnS/FeS(2) system increased by an additional factor of 1.3 at the same temperature. By comparison, the ratio of Cu dissolution from CuFeS(2) in acid-bacterial medium and sterile controls (without bacteria) was 5.5. The corresponding ratio for Zn from ZnS was 2.2 at both 30 and 55 degrees C. The order of reaction was found to be essentially first order for the leaching of powder systems at both 30 and 55 degrees C (with T. Ferrooxidans and thermophilic microorganisms, respectively). The corresponding reaction rate constants were observed to be 12.6 and 22.9 for T. ferrooxidans and the thermophilic microorganisms, respectively. Activation energies for the various systems were also determined.
Mn2+−Nitrogen Interactions in RNA Probed by Electron Spin−Echo Envelope Modulation Spectroscopy: Application to the Hammerhead Ribozyme

We report application of electron spin−echo envelope modulation (ESEEM) spectroscopy to the problem of metal coordination environments in structured RNA molecules. ESEEM has been used in conjunction with 15N-guanosine labeling to identify nitrogen ligation to a Mn2+ site in a hammerhead ribozyme and in Mn2+−model guanosine monophosphate (GMP) complexes. Hammerhead ribozyme complexes consisting of a 34-nucleotide RNA enzyme strand annealed to a 13-nucleotide DNA substrate strand were poised in 1 M NaCl as a 1:1 complex with Mn2+, conditions previously determined to populate a single high-affinity Mn2+ site (Horton, T. E.; Clardy, R. D.; DeRose, V. J. Biochemistry 1998, 51, 18094−18108). Significant modulation of the electron spin−echo from several low-frequency features is detected for the natural-abundance, 14N-hammerhead samples. At 3600 G, the main hammerhead three-pulse ESEEM features arise at 0.6, 1.9, 2.5, and 5.2 MHz and are nearly identical for a Mn2+−GMP complex under the same conditions. For a ri...
Modular and selective biosynthesis of gasoline-range alkanes

Typical renewable liquid fuel alternatives to gasoline are not entirely compatible with current infrastructure. We have engineered Escherichia coli to selectively produce alkanes found in gasoline (propane, butane, pentane, heptane, and nonane) from renewable substrates such as glucose or glycerol. Our modular pathway framework achieves carbon-chain extension by two different mechanisms. A fatty acid synthesis route is used to generate longer chains heptane and nonane, while a more energy efficient alternative, reverse-β-oxidation, is used for synthesis of propane, butane, and pentane. We demonstrate that both upstream (thiolase) and intermediate (thioesterase) reactions can act as control points for chain-length specificity. Specific free fatty acids are subsequently converted to alkanes using a broad-specificity carboxylic acid reductase and a cyanobacterial aldehyde decarbonylase (AD). The selectivity obtained by different module pairings provides a foundation for tuning alkane product distribution for desired fuel properties. Alternate ADs that have greater activity on shorter substrates improve observed alkane titer. However, even in an engineered host strain that significantly reduces endogenous conversion of aldehyde intermediates to alcohol byproducts, AD activity is observed to be limiting for all chain lengths. Given these insights, we discuss guiding principles for pathway selection and potential opportunities for pathway improvement.
Thick thermal barrier coatings for diesel engines

The Caterpillar approach to applying thick thermal barrier coatings (TTBC) to diesel engine combustion chambers has been to use advanced modeling techniques to predict engine conditions and combine this information with fundamental property evaluation of TTBC systems to predict engine performance and TTBC stress states. Engine testing has been used to verify the predicted performance of the TTBC sys-tems and to provide information on failure mechanisms. The objective of the Caterpillar program has been to advance the fundamental understanding of thick thermal barrier coating systems. Areas of TTBC technology examined in this program include powder characteristics and chemistry; bond coat composition; coating design, microstructure, and thickness ef-fects on properties, durability, and reliability; and TTBC “aging” effects (microstructural and property changes) under simulated diesel engine operating conditions. Methods to evaluate the reliability and du-rability of TTBCs have been developed to understand the fundamental strength of TTBCs for particular stress states.
Process zone and size effect in fracture testing of rock

Abstract Fracture of rock involves formation of a localized region of damage or cohesive process zone, which controls size effects on strength and stability. Therefore, any attempt in predicting size of process zone is of prime importance in fracture study of quasi-brittle materials. In this paper, an approximate theoretical relationship between size of process zone and specimen size is proposed. The appropriateness of this relationship is examined by conducting a discrete element analysis of rock fracture. A softening contact bond model is used to study the process zone around a notch tip in three point bending tests. The numerical analysis is utilized to obtain the nominal tensile strength, apparent fracture toughness, and width of process zone. It is shown that the apparent fracture toughness is a function of the specimen size, and that the change in nominal tensile strength with specimen size can be captured by Bazant's size effect law. In addition, both the theoretical arguments and the numerical results suggest that the inverse of width of the crack tip process zone has a linear relationship with the inverse of specimen size. The numerical results indicate a stronger relationship between width of process zone and specimen size for a material with a larger value of characteristic size. On the other hand, for a brittle material, specimen size has a small or no impact on the size of the process zone.
O-polysaccharide glycosylation is required for stability and function of the collagen adhesin EmaA of Aggregatibacter actinomycetemcomitans

Aggregatibacter actinomycetemcomitans is hypothesized to colonize through the interaction with collagen and establish a reservoir for further dissemination. The trimeric adhesin EmaA of A. actinomycetemcomitans binds to collagen and is modified with sugars mediated by an O-antigen polysaccharide ligase (WaaL) that is associated with lipopolysaccharide (LPS) biosynthesis (G. Tang and K. Mintz, J. Bacteriol. 192:1395–1404, 2010). This investigation characterized the function and cellular localization of EmaA glycosylation. The interruption of LPS biogenesis by using genetic and pharmacological methods changed the amount and biophysical properties of EmaA molecules in the outer membrane. In rmlC and waaL mutant strains, the membrane-associated EmaA was reduced by 50% compared with the wild-type strain, without changes in mRNA levels. The membrane-associated EmaA protein levels were recovered by complementation with the corresponding O-polysaccharide (O-PS) biosynthetic genes. In contrast, another trimeric autotransporter, epithelial adhesin ApiA, was not affected in the same mutant background. The inhibition of undecaprenyl pyrophosphate recycling by bacitracin resulted in a similar decrease in the membrane-associated EmaA protein. This effect was reversed by removal of the compound. A significant decrease in collagen binding activity was observed in strains expressing the nonglycosylated form of EmaA. Furthermore, the electrophoretic mobility shifts of the EmaA monomers found in the O-PS mutant strains were associated only with the membrane-associated protein and not with the cytoplasmic pre-EmaA protein, suggesting that this modification does not occur in the cytoplasm. The glycan modification of EmaA appears to be required for collagen binding activity and protection of the protein against degradation by proteolytic enzymes.
Circuit design for a large area high-performance crossbar switch

The methodology for circuit design of large area ICs (LAICs) is discussed. The partitioning and layout strategies for a self-testing, self-reconfigurating LAIC are formulated. It is shown that by proper layout design the circuit sensitivity to the manufacturing defects can be drastically decreased. A LAIC crossbar switch chip, which served as a vehicle for the experimental verification of the described ideas, was designed, fabricated and successfully tested. The built-in current (BIC) sensor was used in the fabricated crossbar IC in order to perform self-testing and self-reconfiguration purposes. >
Filter paper for preservation, storage, and distribution of insect and pathogen DNA samples.

Proper DNA storage is critical for studies involving genetic analysis of insects and for molecular diagnostics of pathogens carried by them. Molecular surveillance of pathogens carried by insects can involve screening of thousands of insect DNA samples. Problems with storage and degradation of these samples can arise. In this study, a simple filter paper-based method for storage and preservation of insect DNA was evaluated using polymerase chain reaction (PCR). DNA was isolated from individual house fly, Musca domestica L., adults by using a cell lysis technique. From 50 house flies known to carry Campylobacter spp., a portion of the DNA sample was stored frozen and another portion was pipetted onto filter paper. At monthly intervals for 7 mo, PCR was conducted using 1 μl of the frozen DNA sample and a 2.0-mm disk from the filter paper samples as the PCR template. Two markers were used, a 450-bp region of the insect mitochondrial DNA (mtDNA) ND5 gene and a 857-bp region of the Campylobacter spp. mtDNA 16S rDNA gene. PCR amplification was successful for all of the samples regardless of the storage method. The filter paper method is a simple and economical way to store, preserve, and distribute DNA samples for PCR analysis.
The Fusarium solani species complex: ubiquitous pathogens of agricultural importance

Summary Members of the Fusarium solani species complex (FSSC) are capable of causing disease in many agriculturally important crops. The genomes of some of these fungi include supernumerary chromosomes that are dispensable and encode host-specific virulence factors. In addition to genomics, this review summarizes the known molecular mechanisms utilized by members of the FSSC in establishing disease. Taxonomy Kingdom Fungi; Phylum Ascomycota; Class Sordariomycetes; Order Hypocreales; Family Nectriaceae; Genus Fusarium. Host range Members of the FSSC collectively have a very broad host range, and have been subdivided previously into formae speciales. Recent phylogenetic analysis has revealed that formae speciales correspond to biologically and phylogenetically distinct species. Disease symptoms Typically, FSSC causes foot and/or root rot of the infected host plant, and the degree of necrosis correlates with the severity of the disease. Symptoms on above-ground portions of the plant can vary greatly depending on the specific FSSC pathogen and host plant, and the disease may manifest as wilting, stunting and chlorosis or lesions on the stem and/or leaves. Control Implementation of agricultural management practices, such as crop rotation and timing of planting, can reduce the risk of crop loss caused by FSSC. If available, the use of resistant varieties is another means to control disease in the field. Useful websites http://genome.jgi-psf.org/Necha2/Necha2.home.html
The Effect of Brand Class, Brand Awareness, and Price on Customer Value and Behavioral Intentions

The author introduces a comprehensive customer value framework and tests an extended value model with lodging products. The extended value model in this study newly incorporates the concepts of brand awareness, as compared to brand or product class, and price fairness. Based on Baron and Kenny’s guideline for mediation analysis, this study found the traditional customer value process to be useful for lodging research and marketing. In addition, brand awareness and price fairness concepts were found to play significant roles in the customer value process. The article includes discussions on both managerial and research implications.
GM-CSF-based cellular vaccines: a review of the clinical experience

Immunotherapy is playing an increasing role in the treatment of many cancers. The recent advances in antibody therapy gives much optimism that both passive (antibody therapy) as well as active (vaccine therapy) immunotherapeutic interventions will acquire an increasing presence in oncology. Granulocyte macrophage-colony stimulation factor (GM-CSF)-based vaccines have now been tested in several diseases in a variety of formulations. The success and broad applicability of such an approach rests on the development of an ideal vaccine formulation administered in the appropriate clinical context. This review summarizes the results from the clinical trials performed to date and discusses the future directions of GM-CSF-based cellular vaccine strategies aimed at maximizing the therapeutic benefit.
Analysis of three-dimensional Doppler ultrasonographic quantitative measures for the discrimination of prostate cancer.

Objective. The purpose of this study was to determine whether several quantitative ultrasonographic measures have potential to discriminate prostate cancer from normal prostate and to determine the best combination of these measures. The true spatial distributions of cancer within the prostates studied were obtained histologically after radical prostatectomy. The relationship between Doppler ultrasonography and microvessel count was also investigated. Methods. Three-dimensional Doppler ultrasonographic data were acquired from 39 patients before radical prostatectomy. The removed prostate was sectioned, and whole-mount hematoxylineosin‐stained slides were used to identify all regions of cancer within each prostate. These histologic and ultrasonographic data were spatially registered. Doppler ultrasonographic measures were calculated within uniformly sized three-dimensional regions that were either entirely cancerous or noncancerous, and receiver operating characteristic analysis was performed on the results. Microvessel counts were made within each contiguous cancerous region and correlated with ultrasonographic measures. Results. Color pixel density was the best simple measure for discriminating prostate cancer (accuracy, 80%). The mean power mode value (normalized mean power in color pixels) was inversely related to cancer with an accuracy of 1 ‐ normalized mean power in color pixels = 65% (low mean power is more cancerous). When color pixel density was combined with the normalized mean power in color pixels, its accuracy improved slightly to 84%. The peak microvessel count had a negative correlation with color pixel density as well as with cancer stage. Conclusion. Doppler ultrasonography does provide discriminatory information for prostate cancer, with color pixel density being the most
ARTCC-Initiated Rerouting

*+ Rerouting flights around severe weather or congestion is an important Traffic Flow Management (TFM) strategy. The Federal Aviation Administration (FAA) has been researching ways to improve reroute planning and execution. The purpose of the work documented in this paper is to refine existing reroute planning and execution concepts to more fully address Air Route Traffic Control Center (ARTCC)-initiated rerouting or local rerouting. Local reroutes are performed primarily in instances when the weather is affecting departure routes from an airport in the ARTCC. Initial analysis has shown that the workload involved in local rerouting can be significant. This paper describes a proposal for improvements to the current operations. Central to the concept is an interactive capability available at the Traffic Management Unit (TMU) that presents the traffic manager with a selectable list of flight-specific reroutes, including those submitted by National Airspace System (NAS) users. This capability also allows the traffic manager to understand the effect of each reroute, to submit the reroute amendment to En Route automation, and to revert to the original route if the reroute is no longer needed.
Selection bias in Teratology Information Service pregnancy outcome studies.

Background Pregnancy outcome studies conducted through Teratology Information Services (TIS) rely on volunteer subjects. If these subjects tend to have different risk profiles than the population from which they are drawn, the results of TIS studies may have limited generalizability. Methods We selected all subjects who enrolled in the California Teratogen Information Service (CTIS) pregnancy outcome study for prenatal exposure to carbamazepine or valproic acid between 1990 and 1997 and who received prenatal care through Kaiser Permanente of Southern California (n = 13). We compared these subjects to Kaiser patients identified through the Maternal Serum Alpha Fetoprotein Program with exposure to carbamazepine or valproic acid but who had not enrolled in the CTIS project. The controls were matched by Kaiser location and pregnancy year using a 2:1 ratio (n = 26). Medical records were reviewed and the prevalence of 14 pregnancy risk factors was compared between the two groups. Results There were no significant differences between the groups on any one risk factor; however, a notably higher proportion of women who did not enroll in the CTIS study used tobacco or had a positive family history of congenital anomalies. Conclusions Although the sample was small, and results may not apply to other exposures in different health care environments, these data provide some evidence that women who enroll in TIS pregnancy outcome studies do not have a substantially different pregnancy risk profile than women who do not. Efforts to address possible selection bias should be incorporated in future TIS study design. Teratology 64:79–82, 2001. © 2001 Wiley-Liss, Inc.