cssi/SciSciGPT-SciSciNet huggingface dataset:
Expression and Function in a Transgenic Mouse of an H-2Kb Variant Gene Obtained by Site-Directed Mutagenesis in a Kbm1 Mutant Mouse

H-2Kb is a member of the family of highly polymorphic mouse Major Histocompatibility Complex Class I genes. An in vivo mutant of the H-2Kb allele known as bm1, differs from wild type at three amino acid residues: #152 (glu→ala); #155 (arg→tyr); and #156 (leu→tyr) (Schulze et al 1983). These changes are sufficient to elicit mutant to parent skin graft rejections and to alter class I restricted viral presentation (Melief et al 1983). Transgenic mice were used to investigate the in vivo effect on the function of each of these three amino acids by transferring into bm1 mice single amino acid Kb variant genes obtained by site directed mutagenesis. The genes were wild type Kb except for changes at #152 (glu→ala), #155 (arg→tyr) or #156 (leu→tyr). One transgenic mouse line with the Kb #152 (glu→ala) variant gene in B6.C-H-2bm1 mice was studied extensively.
Lattice-based approach to building templates for natural language understanding in intelligent tutoring systems

We describe a domain-independent authoring tool, ConceptGrid, that helps non-programmers develop intelligent tutoring systems (ITSs) that perform natural language processing. The approach involves the use of a lattice-style table-driven interface to build templates that describe a set of required concepts that are meant to be a part of a student's response to a question, and a set of incorrect concepts that reflect incorrect understanding by the student. The tool also helps provide customized just-in-time feedback based on the concepts present or absent in the student's response. This tool has been integrated and tested with a browser-based ITS authoring tool called xPST.
Cholinergic components of frontal lobe function and dysfunction.

Publisher Summary This chapter reviews cholinergic anatomy, neurochemistry, and physiology related to frontal lobe function. The chapter discusses the contribution of cholinergic dysfunction to Alzheimer's disease (AD) and other disorders associated with cognitive deterioration, as well as the use of drugs to enhance cholinergic activity under these conditions. Finally, imaging strategies, such as functional MRI (fMRI) and positron emission tomography (PET), which are playing an increasingly important role in investigations of the human ACh system, are reviewed. These techniques can be used to investigate effects of cholinergic agonists and antagonists on cognitive performance in healthy and compromised individuals and can assist in disease detection and monitoring of progression, treatment, and clinical outcome. Throughout the chapter, important findings related to the brain cholinergic system are presented and directions for future research are also highlighted.
Structural design of the superconducting poloidal field coils for the Tokamak Physics Experiment

The Tokamak Physics Experiment concept design uses superconducting coils made from cable-in-conduit conductor to accomplish both magnetic confinement and plasma initiation. The Poloidal Field (PF) magnet system is divided into two subsystems, the central solenoid and the outer ring coils, the latter is focus of this paper. The eddy current heating from the pulsed operation is excessive for a case type construction; therefore, a "no case" design has been chosen. This "no case" design uses the conductor conduit as the primary structure and the electrical insulation (fiberglass/epoxy wrap) as a structural adhesive. The model integrates electromagnetic analysis and structural analysis into the finite element code ANSYS to solve the problem. PF coil design is assessed by considering a variety of coil current wave forms, corresponding to various operating modes and conditions. The structural analysis shows that the outer ring coils are within the requirements of the fatigue life and fatigue crack growth requirements. The forces produced by the Toroidal Field coils on the PF coils have little effect on the maximum stresses in the PF coils. In addition in an effort to reduce the cost of the coils a new elongated PF coil design was proposed which changes the aspect ratio of the outer ring coils to reduce the number of turns in the coils. The compressive stress in the outer ring coils is increased while the tensile stress is decreased.
Imaging of subsurface targets using a 3D quadtree algorithm

The imaging of subsurface targets using ground penetrating radar (GPR) is becoming an increasingly important area of research. Conventional image formation techniques expend large amounts of computation to resolve a region fully, even a region of clutter. However, by using multi-resolution techniques, e.g, quadtree algorithms, potential targets and clutter can be discriminated in a computationally efficient way. Prior work has focused on the development of 2D quadtree algorithms for surface targets. For mine detection, target depth adds another dimension; thus, we have developed a 3D quadtree algorithm, and applied a multi-stage detector that uses the energy change between quadtree stages to discriminate target and clutter regions. This algorithm is then tested on computer-generated data, as well as experimental data collected from a model mine field. Results show that target location information can be obtained even under near field and small aperture conditions.
Evaluation of different approaches to modeling the second-order ionospheric delay on GPS measurements

[1] This work evaluates various approaches to compute the second order ionospheric correction (SOIC) to Global Positioning System (GPS) measurements. When estimating the reference frame using GPS, applying this correction is known to primarily affect the realization of the origin of the Earth's reference frame along the spin axis (Z coordinate). Therefore, the Z translation relative to the International Terrestrial Reference Frame 2008 is used as the metric to evaluate various published approaches to determining the slant total electron content (TEC) for the SOIC: getting the slant TEC from GPS measurements, and using the vertical total electron content (TEC) given by a Global Ionospheric Model (GIM) to transform it to slant TEC via a mapping function. All of these approaches agree to 1 mm if the ionospheric shell height needed in GIM-based approaches is set to 600 km. The commonly used shell height of 450 km introduces an offset of 1 to 2 mm. When the SOIC is not applied, the Z axis translation can be reasonably modeled with a ratio of +0.23 mm/TEC units of the daily median GIM vertical TEC. Also, precise point positioning (PPP) solutions (positions and clocks) determined with and without SOIC differ by less than 1 mm only if they are based upon GPS orbit and clock solutions that have consistently applied or not applied the correction, respectively. Otherwise, deviations of few millimeters in the north component of the PPP solutions can arise due to inconsistencies with the satellite orbit and clock products, and those deviations exhibit a dependency on solar cycle conditions.
Structure and Inhibition of Microbiome β-Glucuronidases Essential to the Alleviation of Cancer Drug Toxicity

The selective inhibition of bacterial β-glucuronidases was recently shown to alleviate drug-induced gastrointestinal toxicity in mice, including the damage caused by the widely used anticancer drug irinotecan. Here, we report crystal structures of representative β-glucuronidases from the Firmicutes Streptococcus agalactiae and Clostridium perfringens and the Proteobacterium Escherichia coli, and the characterization of a β-glucuronidase from the Bacteroidetes Bacteroides fragilis. While largely similar in structure, these enzymes exhibit marked differences in catalytic properties and propensities for inhibition, indicating that the microbiome maintains functional diversity in orthologous enzymes. Small changes in the structure of designed inhibitors can induce significant conformational changes in the β-glucuronidase active site. Finally, we establish that β-glucuronidase inhibition does not alter the serum pharmacokinetics of irinotecan or its metabolites in mice. Together, the data presented advance our in vitro and in vivo understanding of the microbial β-glucuronidases, a promising new set of targets for controlling drug-induced gastrointestinal toxicity.
Toeplitz-Plus-Hankel Matrix Recovery for Green’s Function Computations on General Substrates

Rapidly diversifying technology and declining computational costs are popularizing technologically flexible simulation and verification techniques, even at some cost in performance. This paper investigates a data-driven, sampling-based approach for computing substrate Green’s functions, which is more technology flexible than specialized layered media methods, at the cost of speed and accuracy. Our method is based on assuming that grid-sampled Green’s functions can be well approximated by Toeplitz-plus-Hankel (TPH) matrices, and uses a least squares procedure to recover a TPH matrix from a small number of samples. We show that sample location is crucial, and that good sample locations are the ones that minimize an associated graph-diameter-based condition number estimate. The method’s expected effectiveness is demonstrated on noise-polluted samples of layered media Green’s functions. More surprisingly, we show that the method is effective even when applied to a substrate geometry that is only mildly planar.
An Estimation of the Interstellar Contribution to the Zodiacal Thermal Emission

Impact data from the Ulysses dust detector at 5 AU from the Sun have been interpreted as a flux of submicron interstellar dust particles arriving from ecliptic longitude 252° and ecliptic latitude 25. By following the motions of these particles under the influence of solar gravity, radiation pressure, and electromagnetic forces, we derive a model of the thermal emission from the resultant particle cloud. Since the distributions of the particles are time variable depending on the solar cycle, calculations are performed for the years 1984 and 1990, corresponding, respectively, to the times of the IRAS and COBE observations. We also illustrate how the distributions vary with particle size (or, at a more basic level β, the ratio of the radiation pressure to gravitational force) by presenting results for three different particle sizes. Patches of emission from our test cloud reach peak levels of 0.1 MJy sr–1 in the 12 μm wave band. This represents 10% of the average brightness asymmetry around the sky between the trailing/leading telescope pointing directions seen in the IRAS and COBE data sets. Some of these patches occur at high ecliptic latitudes where the contribution from the Galaxy is negligible and emission from the smooth zodiacal background is low compared to that at low ecliptic latitudes. A strong seasonal variation in the predicted interstellar emission trailing/leading asymmetry is the most obvious signature of the interstellar source, and, in addition, the time variability of the emission will produce different features in the IRAS and COBE data sets and in any subsequent infrared mission. For these reasons, a search of the data for the predicted signatures is certainly justifiable.
Convective drying characteristics of azarole red (Crataegus monogyna Jacq.) and yellow (Crataegus aronia Bosc.) fruits

Abstract In this research, drying characteristics and energy requirement for drying of two different genotypes ( Crataegus monogyna Jacq. and Crataegus aronia Bosc.) of azarole ( Crataegus azarolus L.) red and yellow fruits were reported. Azarole fruits were dehydrated in a computer connected convective hot air dryer. Freshly harvested two different genotypes of azarole fruits were dried at 60 and 70 °C temperatures and drying air velocity was selected as 0.25 m/s for both temperatures. Azarole fruits were dehydrated from the initial moisture content of 211% and 273% (percentage dry basis) to a final moisture content of 8–9% for red and yellow fruits, respectively. During experiments, drying product were weighted automatically by the balance per 10 min. Data were transferred to the computer and processed by a software. The results indicated that drying air temperature significantly influenced the total drying time and total energy requirement for drying of both genotype azarole fruits. The minimum specific energy consumption for drying of red and yellow fruits were determined as 42.80 kWh/kg and 27.68 kWh/kg for 70 °C, respectively. In order to reduce drying energy consumption, it can be recommended that the drying temperature must not be less than 70 °C for this application.
Suppression of somatosensory evoked potentials by nitric oxide synthase inhibition in rats: methodological differences.

Abstract We have previously shown that topically applied N G -nitro- l -arginine ( l -NNA), a nitric oxide synthase (NOS) inhibitor, suppressed both somatosensory evoked potentials (SEPs) and vascular responses during sciatic nerve stimulation in rats. Due to the normal tight coupling between cerebral blood flow and neuronal activity, we surmise that the vascular response attenuation may be secondary to the SEP decrease. However, a recent study, in which SEPs were recorded with a `non-contact' electrode placed longitudinally across the cranial window without touching the cortex, did not find a SEP decrease following NOS inhibition. In the present study, we compared SEPs recorded with `contact' and `non-contact' electrodes. Regardless of stimulation methods (sciatic nerve or hindpaw), an electrode in contact with the pial surface overlying the hindlimb somatosensory cortex recorded a steady SEP decline during l -NNA application. In contrast, a `non-contact' electrode did not detect a significant SEP change in the presence of l -NNA. The present results thus confirm the attenuation of SEPs by NOS inhibition.
Effect of the Spiroiminodihydantoin (Sp) Lesion on Nucleosome Stability

The chemical integrity of the DNA is constantly being modified covalently by endogenous and exogenous agents. If not repaired, these DNA lesions play a critical role in carcinogenic and ageing processes of the cell. Though lesions occur throughout the genome, the low redox potential of the guanine bases make them particularly vulnerable to oxidants. One of the major base lesions formed on DNA is 8-oxo-7,8-dihydroguanine (8-oxo-G). Once formed, this lesion can be further oxidized to the enantiomeric spiroiminodihydantoin (Sp) lesion. These Sp lesions are highly mutagenic, leading to G→T and G→C transversion mutations.DNA lesions can alter the binding of critical transcription factors and chromatin components. Here, we explore how the presence of the Sp lesion affects the binding of histone proteins to form nucleosomes. Histone proteins are isolated from chicken erythrocytes, and 146 bp DNA duplexes synthesized with single, enantiomerically-pure Sp lesions placed site-specifically around the center of the sequence. Histone proteins are exchanged onto our target DNA, and the binding of the histones to the DNA is assessed by gel shift to yield changes in free energy of nucleosome formation relative to unmodified control DNA.Our results indicate that although nucleosomes are formed on all 146-mer duplexes, nucleosome stability decreases measurably when a single Sp lesion is present. Both Sp enantiomers bind more weakly than the control, but the two enantiomers do not bind identically. These enantiospecific differences may play a key role in the process of DNA repair. Placement of the lesion within the sequence also has an effect upon binding thermodynamics, potentially reflecting conflicting pressures exerted by the lesion geometry and the bent DNA geometry necessary for protein binding. These findings suggest that formation of the Sp lesion could have dramatic effects on DNA packaging and expression.
Creation of Bifurcation-Type Elastase-Induced Aneurysms in Rabbits

SUMMARY: Elastase incubation was performed in the LCCA in 13 New Zealand white rabbits. Three weeks after incubation, DSA demonstrated that 10 (10/13, 77%) bifurcation-type aneurysms at the origin of the LCCA were present; mean aneurysm neck, width, and height values were 3.7 ± 1.1, 3.8 ± 0.9, and 8.7 ± 2.3 mm, respectively. The LCCA can be used to create bifurcation aneurysms in rabbits.
Tracheal anastomosis using indocyanine green dye enhanced fibrinogen with a near-infrared diode laser

A major obstacle to lung transplantation and combined heart- lung transplantation is dehiscence of the tracheobronchial anastomosis. We explored the possibility of laser welded anastomoses in canine tracheas in vivo. Laser anastomoses were performed on three-quarter circumferential anterior tracheotomies. A continous wave diode laser (808 +1 nm) at a power density of 9.6 watts/cm was used. Human fibrinogen was mixed with indocyanine green dye (ICG, max absorbance 805 nm) and applied to the anastomosis site prior to laser exposure. Animals were sacrificed at 0, 21 and 28 days post-operatively. At sacrifice weld bursting pressures were measured by raising intratracheal pressure using forced ventilation via an endotracheal tube. Sutured and laser welded anastomoses had similar bursting pressures, and exhibited satisfactory histologic evidence of healing. However, compared to polypropylene sutured controls, the laser welded anastomoses exhibited less peritracheal inflammatory reaction and showed visibly smoother luminal surfaces at 21 and 28 days post- operatively. Tracheal anastomosis using ICG dye enhanced fibrinogen combined with the near-infrared diode laser is a promising extension of the technology of laser tissue fusion and deserves further study.© (1990) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Seekers and Saucers: The Role of the Cultic Milieu in Joining a UFO Cult

This UFO cult has been much in the news of late. Of special note in this paper is the very positive redefinition of the role of seeker. Also, the puzzling finding that affective ties between converts and group members seem unnecessary for conversion to occur is discussed, along with the similarly disconcerting idea that the group lacks ritual behavior.
Phenotypic resemblance in birth weight between first cousins.

SUMMARY Birth weight data on 72078 liveborn singletons representing 5981 paternal and 7036 maternal single first cousin kinships were assembled by computerized record linkage from all marriages and livebirths registered in Hawaii during a 38-year period from 1942 to 1979. These kinships represented incrosses of five selected racial groups. An additional 15536 livebirths from 1134 paternal and 1679 maternal cousin kinships provided data on outcrossing between racial groups, and 28952 livebirths from 2379 paternal and 3538 maternal cousin kinships provided data on both incrossing and outcrossing within kinships. Phenotypic resemblance in birth weight between single first cousins was estimated by the covariance and intraclass correlation. The covariances between maternal cousins were generally much higher than those between paternal cousins. Neither heterogeneity in maternal genotypes nor heterogeneity in newborn genotypes had any significant effect on the resemblance between first cousins. These observations have led to the conclusion that maternal influences of non-hereditary origin are of primary importance in determining birth weight in man. The observed non-zero correlation in several groups of paternal cousins was explained in part by the process of preferential selection of mates within and among racial groups by brothers, and probably by the similarity in some maternal characteristics associated with age at childbearing among their wives.
Vocal fold paralysis secondary to cardiac countershock (cardioversion).

Summary Application of electrical energy to the heart is effective in treating many dysrhythmias. There are, however, also disadvantages associated with cardioversion. Employment of external electrical current has been shown to induce epicardial and myocardial damage at the site of electrode application. We present the only case in the English literature of vocal fold paralysis in which the single identified associated event was cardioversion. In this case of temporary vocal fold paralysis, there was no invasive procedure to directly damage the nerve. Echocardiography of the patient revealed a large left atrium, placing the recurrent laryngeal nerve in an abnormal anatomic position where it was vulnerable to the electric current.
Single base-pair deletions induced by bleomycin at potential double-strand cleavage sites in the aprt gene of stationary phase Chinese hamster ovary D422 cells

One possible mechanism for the generation of deletion mutations is inaccurate repair of DNA double-strand breaks. In an attempt to detect such aberrant repair events in intact cells, confluent stationary phase cultures of chinese hamster ovary D422 cells, which are hemizygous for aprt, were treated for two days with low concentrations of bleomycin, and aprt mutant clones were selected and analyzed by polymerase chain reaction and DNA sequencing. Bleomycin was quite mutagenic in stationary phase cells, increasing the mutant frequency by five to 40-fold at 5 to 50% survival. While spontaneous mutations generated under these conditions were predominantly base substitutions, the majority of the bleomycin-induced mutations were very small deletions, with lesser numbers of large deletions/rearrangements and base substitutions. Although the small deletions tended to be clustered in several short segments of the gene, nucleosome positioning studies indicated that there was no consistent phasing of nucleosomes in aprt, suggesting that the clustering was due to sequence specificity rather than chromatin structure. About half of the bleomycin-induced mutations were single-base-pair (-1) deletions, and the majority of these involved deletion of one C in a G-Cn sequence (n > or = 2). At such sites, bleomycin is known to induce double-strand breaks by fragmentation of deoxyribose moieties at the same sequence position in both strands, resulting in a blunt-ended double-strand break with 5'-phosphate and 3'-phosphoglycolate termini. Thus, this sequence specificity is consistent with a model in which bleomycin-induced -1 deletions are generated by a double-strand break rejoining process involving removal of phosphoglycolate moieties from both 3' ends, followed by blunt-end ligation. The results support the view that repair of free radical-mediated double-strand breaks in mammalian cells in G1/G0 phase can be effected by such simple end-joining mechanisms, without the need for homologous recombination.
Changes in plasma gastrin levels during isolated perfusions of canine lung and kidney.

Abstract In an effort to determine whether the lung has any role in the catabolism of gastrin, the synthetic heptadecapeptide was infused into a series of isolated perfused canine lungs. The results indicate that the normal lung does not catabolize gastrin. When interstitial edema supervenes, loss of gastrin from the perfusion mixture occurs which appears to be reversible. Under these circumstances, transudation but not catabolism appears to be occurring.
Gerotor Fuel Pump Performance and Leakage Study

Gerotor pumps are utilized in a number of automotive applications such as fuel lift. Volumetric efficiency and leakage are causes of concern in gerotor pumps. To optimize pump performance and reduce leakage, it is fundamental to comprehend the fluid dynamics inside the pump passageways. In this paper, a three-dimensional CFD methodology has been developed and applied to predict the pump performance, to understand pump flow dynamics and to investigate pump leakage for gerotor pumps equipped in automotive fuel systems. The methodology is based in the commercial code ANSYS FLUENT and the analytical focal points are the pump performance and leakage over a range of motor speeds and output pressures, 4000 RPM and 5400 RPM, also 450 kPa and 600 kPa. The CFD results are first contrasted with the experimental data and a very good agreement has been achieved. Extensive CFD simulations are then conducted to study the effect of the tip clearance on pump flow performance and leakage.Copyright © 2011 by ASME
Reciprocal recurrent selection in sugarbeet

Abstract Sugarbeet root yield is conditioned by both additive and nonadditive types of gene action. The reciprocal recurrent selection breeding method is designed to aid in simultaneously selecting for both types of gene action and requires that plants be both crossed and selfed. For adaptation of this method to sugarbeet, some modification is necessary, because the sugarbeet is normally cross-pollinated and is very difficult to emasculate. Incorporation of the self-fertile gene, S f (dominant), and the male-sterile gene, a 1 (recessive), makes this method useful for sugarbeet improvement. The biennial nature of sugarbeet necessitates a five-year selection cycle. This method incorporates selection for root yield, sugar percent, disease resistance, and “O” type. The amount of material tested for combining ability for yield is reduced to a workable level by selecting for additive, highly heritable traits in the early phases. It can be adapted to any crop having self-fertile and male-sterile genes available in its gene pool.
Mycophenolate mofetil: new applications for this immunosuppressant.

Objectives This article should familiarize the reader with the pharmacokinetics, mechanisms of action, potential toxicities, and current and future applications of mycophenolate mofetil. Data Sources The current medical literature. Results Mycophenolate mofetil is an immunosuppressive agent that has been used for transplant recipients. More recently, this agent has been used to treat several inflammatory conditions. Conclusions Mycophenolate mofetil has the potential to be a useful agent in the treatment of several inflammatory conditions, including systemic lupus erythematosus.
Intracellular acetylcholinesterase of adult rat myofibers is more concentrated in endplate than non‐endplate regions

The intracellular distribution of acetylcholinesterase (AChE) was determined in adult rat anterior gracilis muscles. Echothiophate iodide (ECHO), a water-soluble cholinesterase inhibitor, was applied to muscles in situ to eliminate extracellular and/or extracellularly oriented enzyme. Control and ECHO-treated muscles were either cut into 1-mm segments and assayed for AChE activity or cytochemically stained for AChE. Subsequent analysis by light and electron microscopy showed that the AChE stain inside myofibers was highly localized and clearly visible only in the zone immediately underlying the point of nerve-muscle contact. Biochemical assay of muscle segments showed intracellular AChE to be most highly concentrated in regions containing large numbers of endplates (approximately twice the activity of endplate-free areas). Since such "endplate-rich" segments are in fact mostly extra-synaptic tissue, we conclude that intracellular AChE of adult rat gracilis myofibers, although present along the length of the cell, is more than two times as concentrated in sub-synaptic areas as compared to extra-synaptic areas. This result must be carefully considered when attempting to identify "endplate-specific" AChE activity of mammalian muscle, and further points to the importance of neural influences on AChE metabolism/regulation.
Towards a Critical Theory of al-Nahḍah: Epistemology, Ideology and Capital

AbstractThis articles is an initial theoretical foray into what has become a dynamic burgeoning field—“Nahdah Studies”—by proposing that literary and intellectual production of the era should not be understood as generative or productive of cultural discourses, social practices or identities. Rather, al-Nahdah al-arabīyyah is the mark of a violent epistemological wrenching that was instigated by the introduction of capitalist means of production and surplus accumulation during the Ottoman Tanzimat. Using a handful of examples such as Ahmad Fāris al-Shidyāq, Butrus al-Bustānī, Ibrāhīm al-Yāzijī and Husayn Marsafī, the article suggests that literary and intellectual production of al-Nahdah, like the subjectivities they imagine, are an effect of these transformations, which is first imprinted on language that is charged to organize new systems of signification to make modernity legible and logical. Literary, intellectual and cultural productions, therefore, are an effect of the ideology of modernity that has naturalized the reform movement as a necessary project for social, cultural and political success. The cultural and thought production of al-Nahdah was not productive of “new” concepts of identity, civil society, economic production and gender as much as it was reproductive of nascent, native capitalist ideology, serving to mediate and make sense of the tensions, contradictions and violence inherent to the reorganization of the society, culture and economy of the Ottoman Arab provinces.
Trend of Digital Camera and Interchangeable zoom Lenses with high ratio Based on Patent Application over the past 10 years

Although digitalization has tripled consumer-class camera market scale, extreme reductions in prices of fixed-lens cameras has reduced profitability. As a result, a number of manufacturers have entered the market of the System DSC i.e. digital still camera with interchangeable lens, where large profit margins are possible, and many high ratio zoom lenses with image stabilization functions have been released. Quiet actuators are another indispensable component. Design with which there is little degradation in performance due to all types of errors is preferred for good balance in terms of size, lens performance, and the rate of quality to sub-standard products. Decentering, such as that caused by tilting, sensitivity of moving groups is especially important. In addition, image stabilization mechanisms actively shift lens groups. Development of high ratio zoom lenses with vibration reduction mechanism is confronted by the challenge of reduced performance due to decentering, making control over decentering sensitivity between lens groups everything. While there are a number of ways to align lenses (axial alignment), shock resistance and ability to stand up to environmental conditions must also be considered. Naturally, it is very difficult, if not impossible, to make lenses smaller and achieve a low decentering sensitivity at the same time. 4-group zoom construction is beneficial in making lenses smaller, but decentering sensitivity is greater. 5-group zoom configuration makes smaller lenses more difficult, but it enables lower decentering sensitivities. At Nikon, the most advantageous construction is selected for each lens based on specifications. The AF-S DX NIKKOR 18-200mm f/3.5-5.6G ED VR II and AF-S NIKKOR 28-300mm f/3.5-5.6G ED VR are excellent examples of this.
Adaptations and selection of harmful and other dinoflagellate species in upwelling systems. 2. Motility and migratory behaviour

Abstract The motility and migrational behaviour of upwelling dinoflagellates as adaptations for growth in upwelling systems is evaluated. Traits considered include hydrodynamic streamlining; chain formation; motility rates of single cells and chains; adaptations to turbulence; turbulence sensing; and migrational scattering to avoid turbulence, including its role in the maintenance of indigenous populations. Motility rates are compared to vertical mixing and upwelling rates. Diverse combinations of cell shape, size and motility rates characterize the dinoflagellate species selected for growth in physically energetic upwelling systems. Specific or unique combinations of cell shape, size, propulsion system and swimming rate are not evident. The traits are shared with dinoflagellates generally, and probably reflect their swim-based ecology. Experimental evidence – primarily from Alexandrium catenella – suggests upwelling dinoflagellates can sense turbulence leading to three distinct, but coherent, adaptive responses: chain formation (in such species); increased swimming speed (including non-chain-forming species); and the capacity to re-orient swimming trajectory in response to changes in turbulence, and at time-scales appropriate to survival and growth in the turbulence field being experienced. The added swimming power that dinoflagellates gain through chain formation does not appear to be a major requirement for their selection or success in upwelling systems. Only three of the 42 most prominent dinoflagellates that bloom in eastern boundary upwelling systems form chains, a representation far below expectations. Most chain-forming dinoflagellates are excluded from those upwelling systems. The role of temperature in this exclusion is evaluated. Field and experimental evidence suggests that strong turbulence would be required to overwhelm the swimming-based ecology of the upwelling dinoflagellates and deter their blooms. The Yamazaki–Kamykowski model demonstrating that the cells within a migrating population exposed to wind-induced vertical mixing do not migrate uniformly, but scatter differentially within the mixing layer, is applicable to upwelling dinoflagellates. The adaptive value of migrational scattering is that it protects some of the cells from turbulence-induced mortality or impairment, with the survivors available as potential seed stock for subsequent blooms. It also allows an indigenous population to develop and be maintained. The physically robust features of upwelling systems do not appear to be major impediments to the survival and growth of dinoflagellates.
Living Carbocationic Polymerization of p-Methylstyrene and Sequential Block Copolymerization of Isobutylene with p-Methylstyrene

Abstract A novel scheme was developed for the synthesis of pure polyisobutylene-poly(p-methylstyrene) block copolymers by sequential monomer addition. The synthesis involves the living polymerization of isobutylene by the TiCl4/methyl chloride:methylcyclohexane or hexanes 40:60 v:v/ -80°C system in the presence of di-tert-butylpyridine. When the polymerization of isobutylene is complete, the living polyisobutylene chain end is transformed to the corresponding diphenyl alkyl end by capping with 1,1-diphenylethylene. Subsequently, titanium(IV) isopropoxide or titanium(IV) butoxide is added to decrease the Lewis acidity followed by the addition of p-methylstyrene. The success of the method was demonstrated by p-methylstyrene homopolymerization experiments initiated by 2-chloro-2,4,4-trimethylpentane that resulted in ∼ 100% initiator efficiencies when the TiCl4/titanium(IV) isopropoxide or -butoxide ratio was less than 25/7, as well as by the clean synthesis of polyisobutylenepoly(p-methylstyrene) diblock cop...
Uniform GTD solution for the diffraction by metallic tapes on panelled compact-range reflectors

Metallic tape is commonly used to cover the interpanel gaps which occur in paneled compact-range reflectors. It is therefore of interest to study the effect of the scattering by the tape on the field in the target zone of the range. An analytical solution is presented for the target zone fields scattered by 2D metallic tapes. It is formulated by the generalized scattering matrix technique in conjunction with the Wiener-Hopf procedure. An extension to treat 3D tapes can be accomplished using the 2D solution via the equivalent current concept. The analytical solution is compared with a reference moment method solution to confirm the accuracy of the former.
Comparative Study of High Performance Liquid Chromatographic Methods for the Determination of Tetracycline Antibiotics

Abstract This work reviewed all the past HPLC methods utilized for the detection of tetracyclines and created a model to study the most promising ones. Three general mobile phases were investigated. They included Mobile Phase I (0.05 M buffer (A)-acetonitrile (B) programmed from 85A:15B to 40A:60B), Mobile Phase II (0.05 M buffer (A)-acetonitrile (B)-methanol (C) programmed from 80A:0B:20C to 30A:50B:20C), and Mobile Phase III (0.05 M buffer (A)-acetonitrile (B)-dimethylformamide (C) programmed from 80A:OB:20C to 30A:50B:20C). Buffers made from citrate, oxalate, and phosphate, each prepared at pH 2.0, 4.5, and 7.0, were used with each mobile phase. Ethylenediaminetetraacetic acid (EDTA) at 0.005 M was added to the pH 4.5 and pH 7.0 buffers (it would not dissolve in pH 2.0 buffers). Tetramethylammonium chloride (TMA) was also added at 0.01 M to all of the buffers at each pH. The columns chosen for this study were a CIS bonded to silica (Supelco LC-18), a “deactivated” C18 bonded column (Supelco LC-18-DB), ...
Monoclonal idiotope vaccine against Streptococcus pneumoniae infection

A monoclonal anti-idiotope antibody coupled to a carrier protein was used to immunize BALB/c mice against a lethal Streptococcus pneumoniae infection. Vaccinated mice developed a high titer of antibody to phosphorylcholine, which is known to protect against infection with Streptococcus pneumoniae. Measurement of the median lethal dose of the bacteria indicated that anti-idiotope immunization significantly increased the resistance of BALB/c mice to the bacterial challenge. Antibody to an idiotope can thus be used as an antigen substitute for the induction of protective immunity.
Depressive symptoms in low-income women in rural Mexico.

Background: Depression is a leading cause of death and disability worldwide. This paper reports a cross-sectional analysis of demographic, socioeconomic, physical, and psychosocial factors associated with depressive symptoms among poor women in rural Mexico. Methods: A cross-sectional study of 5457 women, age 20-70 years, were interviewed from a random sample of households from 279 poor communities with fewer than 2500 inhabitants in 7 rural Mexican states. Depressive symptoms were assessed using the Spanish translation of the Center for Epidemiologic Studies-Depression scale. Several other individual- and household-level variables were also obtained. Using hierarchical modeling, linear regression analysis, and population intervention model parameters, we explored correlates of depressive symptoms in this population. Results: Most of the variation in depressive symptoms was at the individual level. Psychosocial factors were most strongly correlated with depressive symptoms; perceived stress, lack of personal control or social support, and low social status exhibited the strongest associations. Using the US-based standard Center for Epidemiologic Studies-Depression cutoff score of 16, 51% of this population fall into the category "at risk" for clinical depression; however, this cutoff may not be the most appropriate in this context. Conclusion: This sample of low-income women in rural Mexico reported a relatively high prevalence of depressive symptoms. The analyses suggest that reducing perceived stress would have the largest potential impact on depressive symptoms in this population. However, any interventions should take into account the broad context of the population's overall health. The alleviation of poverty, improvement of educational opportunities, and other interventions to address root causes of poor mental health must also be considered.
Detection of Anaerobic Metabolites of Saturated and Aromatic Hydrocarbons in Petroleum-Contaminated Aquifers

Recent investigations have demonstrated that several classes of petroleum hydrocarbons are susceptible to anaerobic decay, including alkanes and mono- and polycyclic aromatic compounds. In previous work, benzylsuccinates were shown to be useful indicators of in situ anaerobic alkylbenzene metabolism. In the present study, we sought to determine whether metabolites of alkanes and naphthalenes could similarly be used as indicators of the intrinsic decomposition of these compounds in petroleum-contaminated aquifers. Such metabolites include succinate derivatives of n-alkanes, cyclic alkanes, and alkylaromatic hydrocarbons as well as naphthoic acids. Using gas chromatography−mass spectrometry (GC−MS), we analyzed trimethylsilyl-derivatized organic extracts from six hydrocarbon-contaminated groundwaters for MS fragment ions indicative of such anaerobic metabolites. Geochemical indicators in these aquifers suggested the prevalence of anaerobic processes. In the groundwaters of the contaminated sites, we found c...
Synthesis, Characterization, and Photocatalytic Activity of Titania and Niobia Mesoporous Molecular Sieves

Mesoporous titania and niobia molecular sieves were prepared by a ligand-assisted templating method. For comparison, titania samples were also prepared by simple hydrolysis and condensation of Ti alkoxide in the absence of templating agents. All materials were thoroughly characterized by UV−vis reflectance spectroscopy, N2 adsorption, and X-ray diffraction. The UV absorption thresholds, and thus the optical band gaps, of as-synthesized mesoporous titania and niobia were similar to those of bulk phase, crystalline reference materials. Adsorption of N2 showed that extremely high surface area materials were synthesized by the templating method as long as thermal treatments were moderate. Higher temperature caused loss in surface area and partial crystallization of the sample. Elemental analysis revealed that neither high-temperature calcination nor solvent extraction removed the phosphorus component of the template used in the synthesis of mesoporous titania. However, solvent extraction of the template was e...
The Beneficial Effect of Delayed Compressive Loading on Tissue-Engineered Cartilage Constructs Cultured with TGF-β3

Summary Objective To determine whether the functional properties of tissue-engineered constructs cultured in a chemically-defined medium supplemented briefly with TGF-β3 can be enhanced with the application of dynamic deformational loading. Methods Primary immature bovine cells (2–3 months old) were encapsulated in agarose hydrogel (2%, 30×10 6 cells/ml) and cultured in chemically-defined medium supplemented for the first 2 weeks with transforming growth factor beta 3 (TGF-β3) (10μg/ml). Physiologic deformational loading (1Hz, 3h/day, 10% unconfined deformation initially and tapering to 2% peak-to-peak deformation by day 42) was applied either concurrent with or after the period of TGF-β3 supplementation. Mechanical and biochemical properties were evaluated up to day 56. Results Dynamic deformational loading applied concurrently with TGF-β3 supplementation yielded significantly lower (−90%) overall mechanical properties when compared to free-swelling controls. In contrast, the same loading protocol applied after the discontinuation of the growth factor resulted in significantly increased (+10%) overall mechanical properties relative to free-swelling controls. Equilibrium modulus values reach 1306±79kPa and glycosaminoglycan levels reach 8.7±1.6% w.w. during this 8-week period and are similar to host cartilage properties (994±280kPa, 6.3±0.9% w.w.). Conclusions An optimal strategy for the functional tissue engineering of articular cartilage, particularly to accelerate construct development, may incorporate sequential application of different growth factors and applied deformational loading.
Structural Fuse Concept for Bridges

The concept of designing sacrificial elements to dissipate seismic energy while preserving the integrity of the structure's other main components is known as the structural fuse concept. Few implementations of this concept have been rigorous in emphasizing replaceability of the sacrificial elements and absence of damage to the primary load-resisting structural system. Here the concept is applied to an innovative multicolumn accelerated bridge construction (ABC) pier concept. Different types of structural fuses are investigated to compare the effect of each on ABC bridge bents. A three-span continuous bridge prototype having two twin-column pier bents with fixed base spaced at 36 m (120 ft) and 9 m (30 ft) tall was designed according to AASHTO load and resistance factor design specifications. Its piers were designed with double-composite rectangular columns using Bi-Steel panels and structural fuses. Two corresponding 2/3-scale models were developed and tested. The two specimens were designed for a maximum...
Properties of adenylate cyclase in mucosal cells of the rabbit ileum and the effect of cholera toxin

A study of the properties of adenylate cyclase in mucosal epithelial cells of rabbit ileum has been performed under control conditions and after stimulation by cholera toxin. A 3–5 fold stimulation of enzyme activity occurred after treatment with cholera toxin. Optimal conditions for activity were attained with Mg2+ concentrations between 5 and 25 mM at a pH of 8.0–9.0. Linearity of reaction rate was achieved over 25 min at protein concentrations of the homogenate of up to 40 μg per 50 μl incubation mixture when an ATP regeneration system was employed. Mn2+ at 3·10−4 to 1·10−3 M could replace Mg2+ but was inhibitory at 5 mM. Ca2+ was inhibitory at all concetrations above 10−5 M. Michaelis-Menten plots were linear with regard to ATP concentrations under both sets of of conditions, V was 28 pmoles·mg−1 protein·min−1 for control and 90 pmoles·mg−1 protein·min−1 for toxin-treated enzyme. Km for both conditions were 4·10−4 M. No evidence of cooperativity was detected. The mechanisms of activation by F− and cholera toxin were presumed different from an analysis of experiments involving combinations of F− and toxin and by a study of pyrophosphate inhibition. Isoproterenol at 10−5 M was stimulatory to the control enzyme, while no effect of epinephrine or propranolol was detected. In contrast, isoproterenol, epinephrine and propranolol were inhibitory to the enzyme after stimulation by cholera toxin.
System parameter identification in transport models using the fast Fourier transform (FFT).

Abstract The fast Fourier transform (FFT) was investigated for potential use in a new application: the system identification problem in physiological transport models. It was found to offer specific advantages when compared to another well-established transform technique, time segment transformation (TST), in which input stimuli are modeled as a time sequence of polynomial functions. The FFT reduced both computing time and core requirements by a factor of 2. The two methods produced virtually identical parameter estimates and the FFT was unaffected by truncation of input data. Proper use of the FFT requires some care, but the pitfalls are identified so that others can avoid them. The time required to develop a system identification program using the FFT is short compared to that of the TST due to the availability of FFT subroutines on most computer systems. The FFT approach can also be applied to a broad class of engineering system identification problems.