cssi/SciSciGPT-SciSciNet huggingface dataset:
Human reticular formation: Cholinergic neurons of the pedunculopontine and laterodorsal tegmental nuclei and some cytochemical comparisons to forebrain cholinergic neurons

Choline acetyltransferase immunohistochemistry showed that the human rostra1 brainstem contained cholinergic neurons in the oculomotor, trochlear, and parabigeminal nuclei as well as within the reticular formation. The cholinergic neurons of the reticular formation were the most numerous and formed two intersecting constellations. One of these, designated Ch5, reached its peak density within the compact pedunculopontine nucleus but also extended into the regions through which the superior cerebellar peduncle and central tegmental tract course. The second constellation, designated Ch6, was centered around the laterodorsal tegmental nucleus and spread into the central gray and medial longitudinal fasciculus. There was considerable transmitterrelated heterogeneity within the regions containing Ch5 and Ch6. In particular, Ch6 neurons were intermingled with catecholaminergic neurons belonging to the locus coeruleus complex. The lack of confinement within specifiable cytoarchitectonic boundaries and the transmitter heterogeneity justified the transmitter-specific Ch5 and Ch6 nomenclature for these two groups of cholinergic neurons. The cholinergic neurons in the nucleus basalis (Ch4) and those of the Ch5-Ch6 complex were both characterized by perikaryal heteromorphism and isodendritic arborizations. In addition to choline acetyltransferase, the cell bodies in both complexes also had high levels of acetylcholinesterase activity and nonphosphorylated neurofilament protein. However, there were also marked differences in cytochemical signature. For example, the Ch5-Ch6 neurons had high levels of NADPHd activity, whereas Ch4 neurons did not. On the other hand, the Ch4 neurons had high levels of NGF receptor protein, whereas those of Ch5-Ch6 did not. On the basis of animal experiments, it can he assumed that the Ch5 and Ch6 neurons provide the major cholinergic innervation of the human thalamus and that they participate in the neural circuitry of the reticular activating, limbic, and perhaps also extrapyramidal systems.
A maximal-order theorem for optimal rational models

The problem of finding an optimal approximating model (in L 2 -sense) to a fixed filter out of the class of rational filters of "order" \leq k is considered. After the existence question is settled, it is shown that such an optimal model must in a certain sense be of maximal-order k .
Study on ketalization reaction of polyvinylalcohol by ketones. I. Reaction between polyvinylalcohol and acetone

Ketalization reaction of polyvinylalcohol (PVA) by acetone, dimethylsulfoxide (DMSO) as solvent, under the presence of acidic catalyst, in homogeneous system was carried out and the synthesis of polyvinylketal with any ketalization degree was successfully performed. This reaction proceeds in bimolecular reaction, the equilibrium constant is ca. 0.07 at 40°C and roughly 10−5 less compared with the acetalization reaction between PVA and aldehydes. Synthesis in aqueous media is difficult. However, the heat of reaction for both cases is 7.5 kcal/mol and both reactions are considered to proceed in an identical reaction mechanism. Ketalization reaction starts from isotactic OH portion and proceeds finally to syndiotactic OH portion, however, 100% ketalization is extremely difficult. The effects of water on reaction was confirmed both from theoretical and experimental viewpoints, and even though the presence of water lowers the degree of ketalization, it was observed that the presence of water below 0.1 mol against 1 mol of PVA will not significantly affect final ketalization degree. Polyvinylketals thus obtained are soluble in DMSO, dimethylformamide (DMF), and alcohols.
Research opportunities in transportation system characteristics and operations

Abstract This paper describes several major research opportunities in the area of transportation “supply” over the next 3–5 years. The general focus of all these topics is on service design. These research topics are classified into three principal categories: capacity provision, vehicle scheduling and vehicle control. In the category of capacity provision, the major research topics are airside airport capacity, freight-terminal location and vehicle-fleet sizing. Vehicle scheduling topics include route and schedule design, empty-vehicle redistribution and routing of hazardous materials. The topics discussed in the category of vehicle control are highway safety, air-traffic control and traffic-management systems. Associated with these various topical areas are five important methodological themes: (a) vehicle utilization; (b) development of stochastic models; (c) decentralized control of complex systems; (d) data collection, processing and presentation; (e) supply-demand interactions.
QUANTITATIVE ANALYSIS OF OLIGONUCLEOTIDES BY MATRIX-ASSISTED LASER DESORPTION/IONIZATION MASS SPECTROMETRY

Quantitative aspects of oligonucleotide analysis by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry remain largely unexplored relative to the efforts that have been devoted to quantitative peptide and protein analysis. The successful quantitation of these other biopolymers coupled with the potential of rapid nucleic acid analysis by desorption/ionization techniques prompted the present investigation into quantifying mixed base oligonucleotides of intermediate molecular weights. This report describes the concentration-dependent desorption/ionization of a 21-base oligonucleotide (MW 6361) using a 36-base oligonucleotide (MW 11 131) as an internal standard. Peak height and peak area ratios (analyte to internal standard) varied linearly as a function of oligonucleotide concentration (R2 = 0.966 and 0.991, respectively). The linearity of response extended over nearly three orders of magnitude, from 0.125 to 100 pmol of analyte applied. The use of an internal standard improved the linearity of the calibration curve and reduced relative standard deviations. These results demonstrate for the first time the quantitation of medium size oligonucleotides using MALDI.
Semiconductor Lasers For Space Sensor Applications

Semiconductor injection lasers are an important ingredient required for realizing advanced sensor systems for space missions. Their main roles are envisioned in pumping and injection locking of solid state lasers, and as direct sources in shorter range applications.
Is coronary artery calcium mass related to Agatston score?1

Abstract Rationale and objectives The objective of this study was to investigate the relationship between the coronary calcium mass and Agatston score measured on multidetector row computed tomography. Materials and methods Eighty-three consecutive subjects (60 men and 23 women) referred for coronary screening were examined by prospectively electrocardiogram-triggered sequential multidetector row computed tomography scan (4 × 2.5-mm collimation). Their coronary calcium was quantitated by means of the Agatston scoring and mass method. The values of score and mass were transformed by taking the natural logarithm (ln(value+1)) to reduce skewness. The relationship between the mass and score was analyzed with multiple regression analysis. Results Fifty-one subjects had a total of 328 calcified lesions detected and measured. The relationship between the calcium mass and score in 51 subjects conformed well to a linear relationship (r2 = 0.96). When analyzed in the total of 328 lesions, the relationship had a good empiric fit with a nonlinear (quadratic) model (r2 = 0.96). The best-fit equation was ln(lesion mass+1)=−0.87+0.67×ln(lesion score+1)+0.10×(ln(lesion score+1)−2.86)2. This relationship was consistent in different coronary vessels and at different heart levels (r2 = 0.96 − 0.99), although there was a higher image noise at lower heart levels (paired t-tests, P Conclusion A nonlinear (quadratic) relationship existed strongly and consistently between coronary calcium mass and score, demonstrating a possible cross-sectional conversion between the two measurements.
14·8 MeV neutron-induced (n, 2n), n, p) and (n, α) cross-sections for some closed shell nuclides

Abstract The activation cross-sections for 12 (n,p), (n,α) and (n,2n) reactions have been determined with 14·8 MeV neutrons using enriched sample materials and Ge(Li) γ-ray detection. The closed shell nuclides studied are 54Fe, 90Zr, 92Mo, 141Pr and 144Sm. The measured (n,2n) cross-section values are compared with those calculated by theoretical and empirical methods, and to plots of σ(n, 2n) vs the asymmetry parameter. A plot of the (n,2n) experimental data, which accounts for differences in nuclear radii and threshold energies for the same value of asymmetry parameter, is presented.
A foundation for enhancing your IEEE involvement

As early as my sophomore year in college, I began receiving calls from my university alumni association soliciting donations. Earning my college degree seemed to make me an even bigger target for charitable solicitations from various organizations. There are so many worthy organizations, and it's great to help our universities prepare for future generations of graduates, but students and young professionals may not have philanthropic resources available, especially as we tackle student loans and save for our futures. We all may be a little guilty of avoiding or ignoring information coming from nonprofit organizations, thinking they are just trying to get something out of our paltry bank accounts, although they may have an important message to share.
Tundras trigger ice ages

For half a century since Milankovich proposed the idea, climatologists have been intrigued by the possibility that cyclical convergences of variations in the earth's orbit and rotation have brought on ice ages. These variations include the planet's precession, the precession of the equinoxes, and the configuration of earth's orbit about the sun. But the most sophisticated mathematical models incorporating these changes have not yielded the conditions for ice ages, according to National Center for Atmospheric Research (NCAR) investigator Tzvi Gal-Chen. This, even though the models include a feedback mechanism that would reproduce cumulative effects. Milankovich suggested that cooler summers in the northern hemisphere would produce less melting of snow and ice in the summer. Because snow and ice reflect sunshine well, their accumulation would lead to more cooling, creating a snowball effect and setting off an ice age.
Cooperative binding of a complement component to antigen-antibody complexes--I: complexes containing rabbit IgG antibody.

Abstract The reversible binding of the first component of guinea pig complement in its enzymatically active from (Cl) ‡ to antigen-antibody complexes has been measured over a 200-fold range of input Cl concentration. The complexes consisted of dinitrophenylated sheep erythrocytes carrying bound rabbit IgG antibody against the ϵ-N-(2,4-dinitrophenyl)-lysine group. Bound and free Cl were measured separately. The binding of Cl to these complexes shows positive homotropic cooperativity. This cooperative binding is consistent with an allosteric interpretation of antibody function.
Interleukin-1 induces protein tyrosine phosphorylation in T cells.

Interleukin (IL)-1α activates multiple signal transmission pathways inthe T helper type 2 cell line, D10A, and these pathways are linked to two separate IL-1 receptors (IL-1R). In the present report we show that IL-1 induces the activation of tyrosine kinase in these cells, leading to tyrosine phosphorylationof a subset of proteins of 38, 75, 97 and 115 kDa. This type of phosphorylation is prevented by a monoclonal antibody directed against the 80-kDa IL-1R and by tyrphostins which are specific inhibitors of tyrosine kinases. In addition, this inhibitor blocks IL-1- and IL-2-induced proliferation in D10A cells as well as the c-myc and c-myb proto-oncogene mRNA expression inresponse to IL-1. Interestingly, the inhibitor of cAMP-dependent kinase, H-8, only blocks IL-1-induced c-myb, but not c-myc mRNA expression. Altogether, our results demonstrate that the activation of a tyrosine kinase(s) is an early and major event that happens after IL-1/IL-1R interaction, leading to an increase in intracellular cAMP which results in c-myb and IL-5 mRNA expression. Independent of cAMP, by tyrosine phosphorylation of specific substrates IL-1 also induces c-myc andIL-6 mRNA expression and cellular proliferation.
Historical and current molting practices in the U.S. table egg industry.

Induced molting is a management practice used primarily by commercial egg producers to optimize the utilization of their layer flocks. Historically, flocks produced eggs for a laying cycle of 1 yr duration and then were sold. With induced molting, flocks are molted and returned to lay for additional laying periods, thereby spreading fixed costs over longer time and more units of production. It is estimated that today more than 75% of all flocks are molted as a part of a regular replacement program. The decision to molt or to operate an all-pullet program is based upon comparisons of flock performance and prices for replacement pullets, eggs, and feed. Justification for the use of molting, therefore, is in the higher total productivity of flocks, reduced costs associated with production, and reduced industry investments in breeder farms, rearing farms, and hatcheries.
Effect of Gossypol on Some Oxidative Respiratory Enzymes

Gossypol was examined in relation to its effect on certain enzymes and enzyme complexes associated with the tricarboxylic acid cycle and the electron transport system. Succinic dehydrogenase and cytochrome oxidase activity from sweet potato was completely inhibited by gossypol at 7.5 × 10 −3 m and 2.0 × 10 −3 m, respectively. Succinoxidase activity of the same preparations was fully inhibited at a lower concentration, 2.5 × 10 −4 m. This concentration did not affect either succinic dehydrogenase or cytochrome oxidase, the primary and terminal enzymes of the succinoxidase complex. The nature of the intermediate step or steps inhibited at this concentration is not yet known. Gossypol was further shown to inhibit phosphorylation at concentrations having no appreciable effect on oxidation. Inhibition in general was not reduced by increased substrate concentrations in the enzyme systems examined, with the exception of cytochrome c for cytochrome oxidase. Bovine serum albumin was partially effective in reducing gossypol inhibition, provided that it was present before enzyme exposure to gossypol.
Negative Life Events and Non-Suicidal Self-Injury in an Adolescent Inpatient Sample

Although life stressors have been implicated in the aetiology of various forms of psychopathology related to non-suicidal self-injury (NSSI), particularly depression and suicidal behavior, they have rarely been examined in relation with NSSI. The objective of the current study was to assess the association between life stressors and NSSI in adolescent inpatients. Adolescent inpatients (n = 110) completed measures of life events, NSSI, and depressive symptoms at 3 time-points over a 9-month period. Higher rates of life stressors were significantly associated with greater NSSI. This finding held even after covarying concurrent depressive symptoms and gender. Life stressors may have a unique role in the pathogenesis of NSSI. Directions for future research and clinical implications are discussed.
FOLD: Extreme Static Test Compaction by Folding of Functional Test Sequences

This article introduces a new approach to extreme static test compaction for functional test sequences that modifies the sequence in order to enhance the ability to omit test vectors from it and thus compact it. In the new approach, modification of the sequence and omission of test vectors from it are tightly coupled by focusing both subprocedures on subsequences of limited lengths. In a new process that is referred to as folding, a subsequence is partitioned into two halves, and the goal of the modification is to ensure that the two halves are as similar as possible. With similar halves, the expectation is that it will be possible to omit test vectors from the subsequence. Experimental results demonstrate that the procedure produces extremely short functional test sequences for benchmark circuits.
Model for the chromatic properties of gradient-index glass.

A model has been developed which predicts the chromatic properties of gradient-index materials based on the composition of the glass. It yields a gradient Abbe number and a gradient partial dispersion which can be used by the lens designer in the design of achromatic gradient-index lens systems. Over 100 glasses with various ion exchange pairs have been investigated. The result is a gradient Abbe number ranging from −2000 to +5000 and a gradient partial dispersion ranging from −5 to +7. This wide range of gradient Abbe numbers and gradient partial dispersions can be further extended by using a glass which has two exchange ions with one diffusing ion or a glass which has one exchange ion with two diffusing ions. In addition to an extended range, the designer is afforded the luxury of a continuously varying Abbe number rather than the discrete Abbe number of conventional materials.
Contributions of conserved serine and tyrosine residues to catalysis, ligand binding, and cofactor processing in the active site of tyrosine ammonia lyase.

Tyrosine ammonia lyase (TAL) catalyzes the conversion of l-tyrosine to p-coumaric acid using a 3,5-dihydro-5-methylidene-4H-imidazole-4-one (MIO) prosthetic group. In bacteria, TAL is used for production of the photoactive yellow protein chromophore and for caffeic acid biosynthesis in certain actinomycetes. Here we biochemically examine wild-type and mutant forms of TAL from Rhodobacter sphaeroides (RsTAL). Kinetic analysis of RsTAL shows that the enzyme displays a 90-fold preference for l-tyrosine versus l-phenylalanine as a substrate. The pH-dependence of TAL activity with l-tyrosine and l-phenylalanine demonstrates a common protonation state for catalysis, but indicates a difference in charge-state for binding of either amino acid. Site-directed mutagenesis demonstrates that Ser150, Tyr60, and Tyr300 are essential for catalysis. Mutation of Ser150 to an alanine abrogates formation of the MIO prosthetic group, as shown by mass spectrometry, and prevents catalysis. The Y60F and Y300F mutants were inactive with both amino acid substrates, but bound p-coumaric and cinnamic acids with less than 12-fold changes in affinity compared the wild-type enzyme. Analysis of MIO–dithiothreitol adduct formation shows that the reactivity of the prosthetic group is not significantly altered by mutation of either Tyr60 or Tyr300. The mechanistic roles of Ser150, Tyr60, and Tyr300 are discussed in relation to the three-dimensional structure of RsTAL and related MIO-containing enzymes.
Two-electron photoionization processes in He@C60 using the R-matrix with pseudostates and time-dependent close-coupling methods

The R-matrix with pseudostates method is applied to the case of two-electron excitation and ionization processes in He@C60. A finite spherical-well potential, which simulates the effect of the fullerene enclosing cage, is incorporated into the Hamiltonian using a modified R-matrix method, as recently applied to similar single photoionization studies of Xe@C60 and Ca@C60. Comparison is made with time-dependent close-coupling results for two-electron processes in He and He@C60, and excellent agreement is found in the respective descriptions of confinement resonances. Earlier findings are confirmed that the cage potential causes a redistribution between the n = 2 and n = 3 photoionization–excitation cross sections. The R-matrix with pseudostates method, in particular, is well-suited for treating atomic Feshbach resonances and studying multi-electron systems.
The zebrafish (Danio rerio) embryo as a model system for identification and characterization of developmental toxins from marine and freshwater microalgae

The zebrafish (Danio rerio) embryo has emerged as an important model of vertebrate development. As such, this model system is finding utility in the investigation of toxic agents that inhibit, or otherwise interfere with, developmental processes (i.e. developmental toxins), including compounds that have potential relevance to both human and environmental health, as well as biomedicine. Recently, this system has been applied increasingly to the study of microbial toxins, and more specifically, as an aquatic animal model, has been employed to investigate toxins from marine and freshwater microalgae, including those classified among the so-called “harmful algal blooms” (HABs). We have developed this system for identification and characterization of toxins from cyanobacteria (i.e. “blue-green algae”) isolated from the Florida Everglades and other freshwater sources in South and Central Florida. Here we review the use of this system as it has been applied generally to the investigation of toxins from marine and freshwater microalgae, and illustrate this utility as we have applied it to the detection, bioassay-guided fractionation and subsequent characterization of developmental toxins from freshwater cyanobacteria.
Epidemiology of injury-related visits to officebased physicians in the United States, 1991

The National Ambulatory Medical Care Survey (NAMCS) is a sample survey of office-based physicians in the United States conducted by the National Center for Health Statistics, Centers for Disease Control and Prevention. The 1991 sample included 2,540 physicians; 34,183 Patient Record forms were completed. In 1991, there were over 66 million injury-related visits to office-based physicians representing 10% of total visits; this estimate was similar to other sources of data. Injury patients seen in physicians' offices were more likely to be young or middle-aged adults, white, and male. Back symptoms was the most commonly mentioned reason for visit and back sprains was the most frequently recorded diagnosis. The cost of injury-related visits to office-based physicians was estimated to be over $3.5 billion.
A study of the safranine-ascorbic acid photochemical redox reaction.

— Flash-photolysis of safranine in deoxygenated 5 per cent aqueous pyridine produces a transient bleaching, which disappears by a second order process. Very probably this transient species consists of a pair of radicals or radical ions and not of the safranine in the triplet state. These radicals are also produced in chlorophyll sensitized reactions. Present results combined with previous work by us[I] indicate that the chlorophyll sensitization of safranine bleaching involves the formation of these radicals. The direct photochemical reduction of safranine to its leuco form occurs through the intermediate formation of the radicals. The appearance and disappearance of these radicals is fast compared to the role of photochemical formation and thermal disappearance of leuco safranine. Ascorbic acid influences but is not essential to the photo-bleaching of safranine in 5 per cent aqueous pyridine. An increase in ascorbic acid concentration increases the steady-state yield of the radicals but decreases the steady-state yield of the leuco safranine. In the absence of ascorbic acid or other added substance, safranine photobleaches irreversibly in deoxygenated 5 per cent aqueous pyridine. A plausible mechanism is proposed in explanation of the direct photochemical reduction of safranine.
Effect of Defect on Elastic/Plastic and Creep Behavior of Bone: A Finite Element Study

Three-dimensional structure of trabecular bone can be modeled by 2D or 3D Voronoi structure. The effect of missing cell walls on the mechanical properties of 2D honeycombs is a first step towards understanding the effect of local bone resorption due to osteoporosis. In patients with osteoporosis, bone mass is lost first by thinning and then by resorption of the trabeculae [1].Furthermore, creep response is important to analyze in cellular solids when the temperature is high relative to the melting temperature. For trabecular bone, as body temperature (38 °C) is close to the denaturation temperature of collagen (52 °C), trabecular bone creeps [1]. Over the half of the osteoporotic vertebral fractures that occur in the elderly, are the result of the creep and fatigue loading associated with the activities of daily living [2].The objective of this work is to understand the effect of missing walls and filled cells on elastic-plastic behavior of both regular hexagonal and non-periodic Voronoi structures using finite element analysis.The results show that the missing walls have a significant effect on overall elastic properties of the cellular structure. For both regular hexagonal and Voronoi materials, the yield strength of the structure decreased by more than 60% by introducing 10% missing walls. In contrast, the results indicate that filled cells have much less effect on the mechanical properties of both regular hexagonal and Voronoi materials.Copyright © 2007 by ASME
An unsplit, higher-order Godunov method using quadratic reconstruction for advection in two dimensions

Linear advection of a scalar quantity by a specified velocity field arises in a number of different applications. Important examples include the transport of species and energy in low Mach number models for combustion, atmospheric flows and astrophysics, and contaminant transport in Darcy models of saturated subsurface flow. In this paper, we present a customized finite volume advection scheme for this class of problems that provides accurate resolution for smooth problems while avoiding undershoot and overshoot for nonsmooth profiles. The method is an extension of an algorithm by Bell, Dawson and Shubin (BDS), which was developed for a class of scalar conservation laws arising in porous media flows in two dimensions. The original BDS algorithm is a variant of unsplit, higher-order Godunov methods based on construction of a limited bilinear profile within each computational cell. The new method incorporates quadratic terms in the polynomial reconstruction, thereby reducing the L1 error and better preserving the shape of advected profiles while continuing to satisfy a maximum principle for constant coefficient linear advection. We compare this new method to several other approaches, including the bilinear BDS method and unsplit piecewise parabolic (PPM) methods.
On the selection of a subgoal and the use of a priori information in learning control systems

Numerous methods have been proposed for the design of control systems which learn to function in unknown or partially known environments. Most learning schemes are radical departures from the techniques using continuous adjustment of parameters which grew out of early developments in model reference systems. Principal contributions to the area have been controller models and algorithms. In studying these models, the system is abstracted to such an extent that there is quite often a loss of contact with practical considerations. The objective of this paper is to present some results in the theory of learning control, but also to look again at some of the practical problems encountered in applying a learning controller to a problem. This paper defines the subgoal as a subordinate to the primary goal of minimizing the performance index. It must evaluate each decision one control interval after it is instituted. The subgoal problem is to choose a subgoal which will direct the learning process to the optimal as prescribed by the given performance index. An analytical solution is presented and extended heuristically for the general case. This extended method makes use of the a priori information about the plant. Two other problems are also discussed. A fixed grid is used to partition the state space into control situations, and a method of extending the grid is proposed and evaluated. The controller is initialized using the a priori information, too. A full scale simulation confirms that the proposed methods of choosing the subgoal, extending the fixed grid and initializing the controller are improvements over previous methods.
Direct exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increases infectivity of human erythrocytes to a malarial parasite

Abstract Direct exposure to 10 nM 2,3,7,8-TCDD caused a 75% increase and a 2-fold increase in the infectivity of isolated human erythrocytes to P. falciparum after 48 hours when the parasites were in an unsynchronized or synchronized state of growth, respectively. Treatment of human erythrocytes with 10 μM sodium orthovanadate (NaOV), an inhibitor of plasma membrane Ca-ATPase and phosphotyrosine phosphatase, decreased parasitemia by 30%. Co-treatment of RBCs with TCDD and NaOV completely blocked the TCDD-induced increase in parasitemia. Because erythrocytes are anucleated, these results are discussed as evidence for biochemical changes by TCDD without requiring the activation of gene products.
Short-Column Gradient Elution High-Performance Liquid Chromatography for the Rapid Determination of 7-Ethoxycoumarin Metabolites in Liver-Slice Incubates

An improved HPLC method for the analysis of 7-ethoxycoumarin and its metabolites in liver-slice incubation media is presented. The assay is based on short-column gradient elution which permits baseline resolution of the parent drug and three metabolites with a fourfold reduction in analysis time relative to existing HPLC methods. Total assay run time is 10 min. Data establishing method performance are presented which show intra- and interassay precision and accuracy to be within 13 and 7%, respectively, for separately prepared quality control samples.
Follow-up angiography of intracranial aneurysms treated with endovascular placement of Guglielmi detachable coils.

Objective The success of endovascular treatment of intracranial aneurysms with Guglielmi detachable coils (GDCs) is dependent on the long-term exclusion of the aneurysm from the circulation. We reviewed our experience with the long-term angiographic follow-up monitoring of aneurysms that had been treated with GDCs. Methods All patients whose aneurysms had been treated with GDCs between January 1995 and August 1999 and who subsequently underwent follow-up angiography at 6 months or more were included in this study. We reviewed all of the angiographic findings, to determine the percentage of aneurysm occlusion on the initial angiograms and on the last available follow-up angiograms. The categories of aneurysm occlusion used were 100%, >or=95%, and less than 95% occlusion. Results One hundred thirty patients with 141 aneurysms underwent 143 endovascular coiling procedures and subsequently underwent angiographic follow-up monitoring of 6 months or more. There were 102 female and 28 male patients. The mean angiographic follow-up period was 16.7 months (range, 6-62 mo). The initial rates of occlusion were 100% for 56 aneurysms (39%), >or=95% for 65 aneurysms (46%), and less than 95% for 22 aneurysms (15%). Recurrence of one aneurysm (1.8%) was observed. Of the 87 aneurysms that were incompletely occluded initially, there was progressive thrombosis in 40 (46%), stable neck remnants in 23 (26%), and enlargement of the residual neck in 24 (28%). The final occlusion rates, determined on the last available angiograms, were 100% for 88 aneurysms (61%), >or=95% for 31 aneurysms (22%), and less than 95% for 24 aneurysms (17%). No patient experienced repeat or new subarachnoid hemorrhage more than 6 months after the initial treatment. Conclusion Late angiographic follow-up monitoring of aneurysms that have been treated with GDCs demonstrates the durability of the treatment. Aneurysms with large residual neck remnants were subjected to further treatment, whereas aneurysms with small residual neck remnants remain under observation.
Phosphatidylinositol synthase is required for lens structural integrity and photoreceptor cell survival in the zebrafish eye.

Abstract The zebrafish lens opaque (lop) mutant was previously isolated in a genetic screen and shown to lack rod and cone photoreceptors and exhibit lens opacity, or cataract, at 7 days post-fertilization (dpf). In this manuscript, we provide four different lines of evidence demonstrating that the lop phenotype results from a defect in the cdipt (phosphatidylinositol (PI) synthase; CDP-diacylglycerol-inositol 3-phosphatidyltransferase) gene. First, DNA sequence analysis revealed that the lop mutant contained a missense mutation in the lop open reading frame, which yields a nonconservative amino acid substitution (Ser-111-Cys) within the PI synthase catalytic domain. Second, morpholino-mediated knockdown of the cdipt-encoded PI synthase protein phenocopied the cdiptlop/lop mutant, with abnormal lens epithelial and secondary fiber cell morphologies and reduced numbers of photoreceptors. Third, microinjection of in vitro transcribed, wild-type cdipt mRNA into 1–4 cell stage cdiptlop/lop embryos significantly reduced the percentage of larvae displaying lens opacity at 7 dpf. Fourth, a cdipt retroviral-insertion allele, cdipthi559, exhibited similar lens and retinal abnormalities and failed to complement the cdiptlop mutant phenotype. To determine the initial cellular defects associated with the cdipt mutant, we examined homozygous cdipthi559/hi559 mutants prior to gross lens opacification at 6 dpf. The cdipthi559/hi559 mutants first exhibited photoreceptor layer disruption and photoreceptor cell death at 3 and 4 dpf, respectively, followed by lens dismorphogenesis by 5 dpf. RT-PCR revealed that the cdipt gene is maternally expressed and continues to be transcribed throughout development and into adulthood, in a wide variety of tissues. Using an anti-zebrafish PI synthase polyclonal antiserum, we localized the protein throughout the developing eye, including the photoreceptor layer and lens cortical secondary fiber cells. As expected, the polyclonal antiserum revealed that the PI synthase protein was reduced in amount in both the cdiptlop/lop and cdipthi559/hi559 mutants. Furthermore, we used a heterologous yeast phenotypic complementation assay to confirm that the wild-type zebrafish cdipt allele encodes functional PI synthase activity. Taken together, the cdipt-encoded PI synthase is required for survival of photoreceptor cells and lens epithelial and secondary cortical fiber cells. These zebrafish cdipt alleles represent excellent in vivo genetic tools to study the role of phosphatidylinositol and its phosphorylated derivatives in lens and photoreceptor development and maintenance.
The kinesin family member BimC contains a second microtubule binding region attached to the N terminus of the motor domain.

Abstract The kinesin family member BimC has a highly positively charged domain of ∼70 amino acids at the N terminus of the motor domain. Motor domain constructs of BimC were prepared with and without this extra domain to determine its influence. The level of microtubules needed for half saturation of the ATPase of BimC motor domain constructs is reduced by ∼7000-fold at low ionic strength upon addition of this extra N-terminal extension. Although the change in microtubule affinity is less at higher salt, addition of the N-terminal domain still produces a 20-fold increase in affinity for microtubules in 200 mm potassium acetate. A fusion protein of the N-terminal domain and thioredoxin binds tightly to MTs at low salt, consistent with the increased affinity of motor domain constructs (which contain the N-terminal domain) being due to the additional binding of the N-terminal domain to the microtubule. Hydrodynamic analysis indicates that the N-terminal extension is in a highly extended conformation, suggesting that it may be intrinsically disordered. Fusion of the N-terminal extension of BimC onto the motor domain of conventional kinesin produces a similar large increase in microtubule affinity without significant reduction in kcat or velocity in an in vitro motility assay, suggesting that the N-terminal extension can act in a modular manner to increase the microtubule affinity of kinesin motor domains without a decrease in velocity.
Coalition-Building by Party Leaders: A Case Study of House Democrats

This study explores the process by which party leaders build winning coalitions. Focusing on House passage of impoundment legislation in the 93rd Congress, the essay documents the extensive efforts of Democratic leaders to create a viable bill and persuade party members to support it. Analyses of whip counts demonstrate that the leaders passed the impoundment bill in part because they could bargain with and convert “successful” party members whose past career advancement and future achievements depended in part on leadership assistance. The essay concludes by identifying six conditions that nurtured the bargaining capacity of the Democratic leaders and fostered their coalition-building success.1
A comparison of two different ultrasound methods for estimating fetal weight in preterm gestations

A prospective study was conducted to evaluate the estimation of fetal weight in preterm pregnancies by use of ultrasound measurements. Two equations for estimating fetal weight, one proposed by Shepard and associates and the other by Hadlock and associates, were evaluated. The ability to estimate fetal weight accurately was evaluated with respect to birth weight and menstrual age. Shepard's equation is associated with a lower mean signed percent error than Hadlock's, when the birth weight is less than 1500 g (4% vs 12%) or when the menstrual age is between 23 weeks to 30 weeks (2% vs 10%). However when the birth weight is between 1500 g and 3500 g, or the menstrual age is between 31 weeks to 36 weeks, Hadlock's equation has a lower mean signed percent error: 1% vs -4% for the birth weight category and 2% vs -3% for the menstrual age category. In preterm gestations both equations estimate fetal age weight with a low mean signed percent error--Shephard's -0.4% versus Hadlock's 6.0%.
Neural regulation of sympathetic nerve activity in heart failure

One of the hallmarks of chronic congestive heart failure is an increase in sympathetic tone to the peripheral circulation and to the heart. A correlation between plasma norepinephrine and the severity of the heart failure state has been demonstrated. One mechanism that has been proposed to account for this sympathoexcitation is a depression in the baroreflex and, perhaps, cardiac reflex control of sympathetic nerve activity. This review summarizes work from several laboratories, including our own, that documents a depressed baroreflex control of heart rate and sympathetic nerve activity in both animals and humans with heart failure. The mechanism of the depressed baroreflex most likely is caused by reduced baroreceptor sensitivity as well as enhanced input to the central nervous system from cardiac receptors that are chemosensitive. Although sympathetic tone and arterial baroreflex sensitivity are altered in heart failure, there have been no studies showing a cause-and-effect relationship. Increases in plasma norepinephrine are similar in baroreceptor-denervated and intact dogs paced into heart failure. This latter observation cells into question the traditional concept of baroreceptor-mediated increases in sympathetic tone in heart failure.
Fast Numerical Modeling of Marine Controlled-source Electromagnetic Data Using Quasi-linear Approximation

We developed a fast method for 3-D modeling of marine controlled-source electromagnetic (MCSEM) data in seabed logging (SBL) applications. This method is based on a modified version of quasi-linear (QL) approximation, which speeds up significantly modeling of multitransmitter-multireceiver surveys. The developed code has been tested using synthetic problems and for simulation of MCSEM data for a geoelectrical model of a Gemini salt body.
Separation of aliphatic carboxylic acids by ion-exclusion chromatography using a weak-acid eluent

Abstract The chromatographic behavior of twelve aliphatic carboxylic acids was studied on a 5-μm cation-exchange resin column in the H+-form. A conductivity detector was used without any chemical suppression column. A 0.5 mM solution of benzoic acid or succinic acid was shown to be a suitable eluent. The background conductance of these eluents is much lower than the strongly acidic eluents commonly used and permits a more sensitive detection of the sample acids. Addition of 5% acetonitrile to the eluent greatly reduces the retention times of the later-eluting carboxylic acids and gives sharper peaks.
Sleep debt and depression in female college students

The objective of the study was to evaluate relationships between sleep habits and depressive symptoms. Pilot study data were collected about sleep schedules, related factors and depression in female college students to find whether their sleep schedules correlate with affective symptoms. In the subsequent main study, similar information was collected under more controlled conditions. Depression was measured using the CES-D (Center for Epidemiologic Studies Depression Scale) and HAM-D-3 (modified Hamilton Depression Rating Scale). Response rates were 31.3% of eligible students for the pilot survey and 71.6% for the main study. Both studies showed that about 20% of students reported weekday sleep debts of greater than 2 h and about 28% reported significantly greater sleep debt and had significantly higher depression scores (P 24), were observed in 24% of students. Sleep problems explained 13% of the variance for both the CESD scale and the HAM-D-3 scale. Among female college students, those who report a sleep debt of at least 2 h or significant daytime sleepiness have a higher risk of reporting melancholic symptoms than others.
A Thousand Years of Nonlinear History. By Manuel De Landa. New York: Zone Books, 1997. Pp. 333. $16.00.

The title of this book is an outline of De Landa's agenda. He wants to convey his philosophical approach to history using examples chosen from the last 1,000 years of human history. “Nonlinear” refers to feedbacks and interactions that prevent movement toward a unique equilibrium. The author interprets history through a series of extended metaphors that link biology, geology, and linguistics to human history. The book is divided into sections corresponding to these classifications. The first, “Lavas and Magmas,” makes connections between history and geology; the second, “Flesh and Genes,” connects history and biology; and the third, “Memes and Norms,” connects history with linguistics. Within each section De Landa illustrates his approach with examples from the (approximately) last “thousand years of nonlinear history.”
Modeling, Imitation Training, and the Acquisition of Sentence Phrases.

Abstract Imitation and modeling were compared in a multiple-baseline individual analysis. Probe pictures and training pictures were presented to normal pre-school subjects. In modeling, an adult used sentences—including either participial, prepositional, appositive, or infinitive phrases—to describe training pictures. Without responding to the training pictures, the children were asked to describe the probe pictures. In imitation training, in addition to responding to probe pictures, subjects were reinforced for directly imitating a description of training pictures. The dependent variable was the frequency with which the children used the phrase type being exemplified on training trials to describe pictures presented on probe trials. Both procedures were successful in producing imitation of the structure of the model's utterances on probe trials even though the content of the utterances on probe trials was not imitative. Imitation training was effective for every phrase type and subject while modeling was effective for only some subjects and some phrase types. Relationships between these two procedures and the normal environment of language acquisition were discussed.
Effects of gas diffusion layer (GDL) and micro porous layer (MPL) on cathode performance in microbial fuel cells (MFCs)

Abstract This study focused on novel cathode structures to increase power generation and organic substrate removal in microbial fuel cells (MFCs). Three types of cathode structures, including two-layer (gas diffusion layer (GDL) and catalyst layer (CL)), three-layer (GDL, micro porous layer (MPL) and CL), and multi-layer (GDL, CL, carbon based layer (CBL) and hydrophobic layers) structures were examined and compared in single-chamber MFCs (SCMFCs). The results showed that the three-layer (3L) cathode structures had lower water loss than other cathodes and had a high power density (501 mW/m2). The MPL in the 3L cathode structure prevented biofilm penetration into the cathode structure, which facilitated the oxygen reduction reaction (ORR) at the cathode. The SCMFCs with the 3L cathodes had a low ohmic resistance (Rohmic: 26–34 Ω) and a high cathode open circuit potential (OCP: 191 mV). The organic substrate removal efficiency (71–78%) in the SCMFCs with 3L cathodes was higher than the SCMFCs with two-layer and multi-layer cathodes (49–68%). This study demonstrated that inserting the MPL between CL and GDL substantially enhanced the overall electrical conduction, power generation and organic substrate removal in MFCs by reducing water loss and preventing biofilm infiltration into the cathode structure.
Lysophospholipase activity in rat brain subcellular fractions.

Lysophospholipase activity in brain subcellular fractions was measured by the release of myristic acid from 1-myristoylglycerophosphocholine or through the formation of [32P]glycerophosphocholine from [32P]lysophosphatidylcholine. Although the lysophospholipase activity was highest in microsomes, considerable enzyme activity was also found in other subcellular membrane fractions. The pH optimum for the microsomal enzyme was around 7, whereas the synaptosomes and non-synaptic plasma membranes exhibited a pH maximum around 8. Although the enzyme did not require divalent cations for activity, divalent cations (1 mM) such as Hg2+, Cu2+, and Zn2+ inhibited potently the enzyme activity. Enzyme activity was also partially inhibited by both saturated and polyunsaturated fatty acids (25–200 μM), and the inhibition seemed to be greater in the membrane than in the cytosolic fractions. Ionic detergents such as deoxycholate and taurocholate inhibited the lysophospholipase. On the other hand, the effect of Triton X-100 was biphasic, i.e., stimulation at concentrations below 100 μg/mg protein and inhibition at higher concentrations. Addition of cholesterol (50–250 μg/ml), but not cholesteryl esters, also potently inhibited enzyme activity. The presence of active lysophospholipase(s) in brain is probably an important mechanism for preventing unnecessary accumulation of lysophospholipids which may exert a deleterious effect on the membranes because, of their detergent properties.
Analysis of filament deformation for a freely rotating cup brush

In this paper, a mechanics formulation is outlined and used for evaluating the steady-state, large deflection of a slender member subjected to displacement-dependent centrifugal load. The problem is examined within the context of rotating filamentary cup brushes that are used in surface finishing operations. Several parameters which are closely related to the machining performance and service life of cup brushes are identified and reported, including filament tip spatial distribution and orientation, filament stress, and the steady-state configuration of the working surface of the cup brush during free rotation. Numerical results indicate that filament inertia forces can lead to significant fiber displacement and stress and thus, must be included as an integral part of the design of rotary cup brushes.