cssi/SciSciGPT-SciSciNet huggingface dataset:
The aryl hydrocarbon receptor has an important role in the regulation of hematopoiesis: implications for benzene-induced hematopoietic toxicity.

Abstract The aryl hydrocarbon receptor (AhR) belongs to the basic helix–loop–helix (bHLH) Per-Arnt-Sim (PAS) family of transcription factors. Many of these proteins are involved in regulating responses to signals in the tissue environment such as hypoxia, oxidation–reduction status, and circadian rhythms. Although the AhR is well studied as a mediator of the toxicity of certain xenobiotics, the normal physiological function remains unknown. However, accumulating data support a hypothesis that the AhR has an important function in the regulation of hematopoietic stem cells (HSCs). Persistent AhR activation by dioxin, a potent xenobiotic AhR agonist, results in altered numbers and function of HSCs in mouse bone marrow. Analysis of HSCs from AhR null-allele mice also indicates that lack of AhR expression results in altered characteristics and function of these cells. HSCs from these animals are hyperproliferative and have altered cell cycle. In addition, aging AhR-KO mice show characteristics consistent with premature bone marrow senescence and are prone to hematopoietic disease. Finally, some data suggest that the expression of the Ahr gene is regulated under conditions that control HSC proliferation. The presence of a normal functioning AhR may provide an important advantage to organisms by regulating the balance between quiescence and proliferation and preventing the premature exhaustion of HSCs and sensitivity to genetic alterations. This function assists in the preservation of HSC function and long-term multi-lineage generation over the lifespan of the organism. This also implicates a role for the AhR in the aging process. Furthermore, these functions may affect the sensitivity of HSCs to certain xenobiotics, including benzene. Defining the molecular mechanisms by which these events occur may lead to the identification of previously undefined roles of this transcription factor in human diseases, particularly those caused or affected by xenobiotics.
Incorporation of intrastriatally injected [3H]fucose into electrophoretically separated synaptosomal glycoproteins. I. Turnover and molecular weight estimations

The radioactivity profiles of electrophoresed neostriatal P2 fraction glycoproteins were examined at a series of times (2.5, 3 and 4 h; 1, 5 and 10 days) following intracranial injections of [3H]fucose into the neostriatum. Ten major fucosylglycoprotein peaks were discerned in these profiles and certain aspects of their metabolism were characterized. The half-life of fucosylglycoproteins in the P2 fraction was estimated to be 9.7 days. The half-lives of the individual glycoprotein peaks ranged from 4.9 to 17.9 days. The apparent molecular weights of the glycoprotein peaks obtained by our procedures ranged from 32,000 to 180,000 daltons. One peak (peak VIII) incorporated radioactivity primarily at short intervals following the injection. The time course of [3H] fucose incorporation into this peak suggests involvement in the transport, activation and/or incorporation of fucose in brain. Since intracranial injections of [3H]fucose are incorporated into proteins in the cell body, synaptosomal fractions from caudate neurons alone are labeled by this technique. This may be useful in separating pre- and postsynaptic glycoprotein biochemistry. Finally, we tentatively propose that the glycoprotein peaks observed in neostriatum may be identical to previously isolated glycoproteins of known function or subcellular location.
Phenylalanine Hydroxylase from Chromobacterium violaceum UNCOUPLED OXIDATION OF TETRAHYDROPTERIN AND THE ROLE OF IRON IN HYROXYLATION

A gene encoding phenylalanine hydroxylase has been cloned from Chromobacterium violaceum and expressed in Escherichia coli. The purified phenylalanine hydroxylase contains copper, which does not support enzymatic activity. Upon removal of copper by dithiothreitol (DTT), the enzyme contains substoichiometric amounts of calcium and zinc but little or no redox-active metal ions. The copper-depleted hydroxylase catalyzes the phenylalanine-dependent oxidation of 6, 7-dimethyltetrahydropterin (DMPH4) by O2 in a reaction in which phenylalanine is not hydroxylated and does not appear to undergo a chemical change, and hydrogen peroxide is produced. Analogs of phenylalanine also activate the oxidation of DMPH4. Both the copper-phenylalanine hydroxylase and the copper-depleted hydroxylase catalyze the hydroxylation of phenylalanine in the presence of DTT and FeSO4 in a reaction in which hydrogen peroxide is not produced. The apparent values of Km for Fe2+ and DTT are 0.28 microM and 1.1 mM, respectively, at 1.0 mM phenylalanine, 120 microM DMPH4 and pH 7. 4 and 23 degreesC. The apparent value of kcat is 14.3 s-1 under these conditions. Glutathione, mercaptoethanol, and dihydrolipoate support the hydroxylation of phenylalanine essentially as well as DTT. Incubation of copper-depleted hydroxylase with FeSO4, phenylalanine, and DTT followed by gel permeation chromatography leads to an iron-hydroxylase containing approximately 1 molecule of iron per molecule of enzyme. The iron-hydroxylase displays an optical absorption band extending from 300 to 600 nm, and it catalyzes the hydroxylation of phenylalanine at the same maximum rate as the iron-activated hydroxylase but does not require added Fe2+. We conclude that iron participates in the hydroxylation of phenylalanine. Iron is not required for the oxidation of DMPH4, although it may exert a modest acceleration effect. A hypothetical mechanism is presented wherein the reaction of iron with the putative 4a-hydroperoxy-DMPH4 leads to 4a-hydroxy-DMPH4 and a high valent iron-oxy species. The iron-oxy species is postulated to react with phenylalanine in the hydroxylation process.
Nucleation and growth in Al-Zn: A test of the Langer-Schwartz model.

Small-angle x-ray scattering has been used to monitor the decrease in supersaturation with time in Al-Zn alloys following quenches into the metastable miscibility gap. The results demonstrate that the Langer-Schwartz model of nucleation and growth is accurate provided a time-dependent nucleation rate is included.
APPLIED INFORMATION THEORY by I. M. Kogan. Gordon and Breach, New York, 1988. IX+ 466 pp. Translated from the Russian original Prikiadnaia teoria informatsii (Radio i Svyaz, Moscow, 1979) by K. Mohan Das.

(1989). APPLIED INFORMATION THEORY by I. M. Kogan. Gordon and Breach, New York, 1988. IX+ 466 pp. Translated from the Russian original Prikiadnaia teoria informatsii (Radio i Svyaz, Moscow, 1979) by K. Mohan Das. International Journal of General Systems: Vol. 15, No. 2, pp. 165-167.
Faster geometric k -point MST approximation

Abstract We give fast new approximation algorithms for the problem of choosing k planar points out of n to minimize the length of their minimum spanning tree (equivalently, of their traveling salesman tour or Steiner tree). For any x ≤ k, we can find an approximation achieving approximation ratio O ( log k log x ) in time O(nlogn + 2xknlogk). In particular, we get an approximation with ratio O ( log k log log n ) in time O(kn1+ϵ). We also show how to speed up other approximation methods without worsening their approximation ratios; for instance we can achieve a 1 + ϵ approximation ratio in time O (n( log n+k o ( 1 ϵ ) )) .
MESOGEL NETWORKS VIA SELECTIVE MIDBLOCK SWELLING OF LAMELLAR TRIBLOCK COPOLYMERS

A lamellar ABA triblock copolymer brought to equilibrium in the presence of a B-compatible solvent generally swells or transforms into an A-dispersed (cylindrical or micellar) morphology, depending on solvent content. If the A blocks of the copolymer are glassy, they serve as physical cross-links and stabilize a gel network in which A microdomains are linked through a combination of connected B bridges and entangled B loops. An alternate route by which to introduce solvent into a triblock copolymer, as well as retain the local molecular anisotropy (and bridge population) of the initial lamellar morphology, is to selectively swell the B block and, at sufficiently high solvent concentrations, produce a mesogel. In this work, we describe the formation of mesogels from two chemically related triblock copolymers and employ dynamic mechanical analysis and transmission electron microscopy to examine the features of the resultant nonequilibrium materials.
Human serum α-l-fucosidase

Abstract Human serum α- l -fucosidase has been purified 241 200-fold with 35% yield by an affinity Chromatographie procedure utilizing agarose-ϵ-aminocaproyl-fucosamine. Isoelectric focusing of the purified enzyme indicated the presence of several forms, with the form at pI 5.0 comprising the majority of the activity. Assay of the purified α- l -fucosidase showed only trace amounts of contaminating glycosidases present, with β-galactosidase being the largest contamnant (0.5% by activity). Sodium dodecyl sulfate polyacrylamide gel electrophoresis indicated the presence of two subunits with very similar molecular weights (56500 and 54000). Using the p -nitrophenyl substrate, the purified serum α- l -fucosidase had an apparent Michaelis constant of 0.52 mM and a broad pH optimum centered around pH 4.8 with a second, minor optimum at pH 6.1. Gel filtration on Sepharose 6-B indicated an apparent molecular weight of 296 000 ± 30 000. Preincubation with antibodies made previously against purified liver α- l -fucosidase led to quantitative immuno precipitation of the purified serum α- l -fucosidase. Assay of the purified serum α- l -fucosidase for sialic acid indicated the presence of 1.7 μg sialic acid per 100 μg enzyme, about twice that previously found for the purified liver enzyme.
Autoantibodies to extracellular collagen matrix components in epidermolysis bullosa and other bullous diseases.

In order to determine whether autoantibodies are present in sera from normal individuals and/or patients with selected bullous disorders, a highly sensitive solid-phase radioimmune assay was established using purified native collagen types I–VI, laminin, and fibronectin as substrates. Sixty-four sera were utilized, representing 12 normal controls as well as 4 patients with extensive thermal burns, 18 with autoimmune bullous diseases (11 bullous pemphigoid, 5 pemphigus vulgaris, and 2 epidermolysis bullosa acquisita), and 30 with non-autoimmune mechanobullous diseases [epidermolysis bullosa (EB): 20 simplex, 4 junctional, and 6 dystrophic]. In general, autoantibodies to types I, II, and VI collagen and fibronectin were undetectable in any of the patient or control groups. In contrast, autoantibodies to types III and V collagen were noted in 87.5% (28/32) and 90.6% (29/32) of EB sera, respectively, while being only rarely noted in sera from other patient groups. Similarly, autoantibodies to type IV collagen and laminin were detected in 50% (16/32) and 40.6% (13/32) of EB sera, especially from patients with simplex and dystrophic forms of the disease. These data suggest that selected interstitial and basement membrane-associated collagens and laminin may become autoimmunogenic in all three forms of inherited EB in contrast to their relative lack of immunogenicity in at least some of the other intraepidermal and subepidermal blistering disorders. The role, if any, of these autoantibodies in the induction or perpetuation of blistering in EB awaits further studies.
Guaranteed decentralized pursuit-evasion in the plane with multiple pursuers

Pursuit-evasion games are an important problem in robotics and control, but games with many players are difficult to analyze and solve. This paper studies a game of multiple pursuers cooperating to capture a single evader in a bounded, convex, polytope in the plane. We present a decentralized control scheme based on the Voronoi partion of the game domain, where the pursuers jointly minimize the area of the evader's Voronoi cell. We prove that capturing the evader is guaranteed under this scheme regardless of the evader's actions, and show simulation results demonstrating the pursuit strategy.
Actor–Networks, Farmer Decisions, and Identity

Climate change and industrial agricultural practices pose threats to the future of Kansas agriculture. To inform the debate about sustainable agriculture that must soon occur, we seek to illuminate the factors involved in the decision making of farmers in Kansas. Drawing from Actor–Network Theory, we consider how farmers' participation in the industrial agricultural network shapes their decisions, defines the types of knowledge and skills that are valued by farmers and others in the network, transforms what it means to be a Kansas grain farmer, and entrenches unsustainable production practices.
Establishment of ‘Tifton 9’ Bahiagrass in Response to Planting Date and Seed Coat Removal

Stands of 'Tifton 9', like those of other bahiagrasses (Paspalum notatum Flugge var. saurae Parodi), develop slowly. Our objectives were to determine seedling emergence and stand establishment responses to planting date and mechanical seed coat removal using greenhouse and field plantings. Seed dehulled by acceleration in an airstream to hit a metal plate (7.8 kg ha -1 ) or whole seed (11.2 kg ha -1 ) was planted at equivalent rates in five blocks of a randomized complete block design on seven biweekly planting dates from 9 March through 1 June in 1994 and 1995 at both a droughty upland site (Dothan loamy sand: fine-loamy, siliceous, thermic Plinthic Kandiudults) and a lowland site (Alapaha sand: loamy, siliceous, thermic Arenic Plinthic Paleaquults) near Tifton, GA (31°26' N, 83°35' W), to observe emergence and establishment. Spring and fall plant counts and final stand ratings of percent bahiagrass occurrence were used to evaluate emergence and establishment. Emergence 7 d after greenhouse planting of dehulled seed (18.3%) was greater (P < 0.01) than whole seed (0.7%). Emergence at 28 d after planting was not different (36.2%) between seed treatments. Mean surface (0 to 50 mm) soil moisture content at the lowland site (58 g kg -1 ) was higher than the upland site (28 g kg -1 ), Seedling heights, measured in June 1994, spring seedling number in both years, and 1995 fall plant numbers were often higher with earlier planting date. No differences in final stand (% occurrence) could be attributed to planting date. Final stand ratings were greater (P < 0.05) at the lowland (84%) than at the upland site (79%), and greater (P < 0.05) for whole than for dehulled seed in 1994, but no differences were observed in 1995. Development of Tifton 9 bahiagrass stands at these Coastal Plain sites was slow, but relatively insensitive to differences in spring or early summer planting date. Dehulled seed emerged more rapidly, but this provided no sustained advantage in stand establishment in these environments.
Mobilities of thermal electrons in gases and liquids

Abstract Mobilities, μ G , of thermal electrons in a number of gases are reported, compared with those, μ L , in the corresponding liquids, and discusse
Ecological log-rolling

Abstract The purpose of this note is to study a modification of the Markov chain solution concept of Fiorina, Ferejohn, and Packel (1978) which is quadratic instead of linear, and which in particular may be useful for log-rolling games (Oppenheimer, 1979). This quadratic process reduces to a linear complementarity problem, as its stable equilibrium. In the log-rolling games in question, each player has a favorite proposal which is slightly unfavorable to the others. Any majority can guarantee any set of proposals. The utility of any set of any player is the sum of the utilities of the proposals in the set.
Initial 5-Fluorouracil Trabeculectomy in Uncomplicayed Glaucoma

Abstract The effectiveness of trabeculectomy with adjunctive low-dose 5fluorouracil (5-FU) as the initial surgical procedure in uncomplicated glaucoma was evaluated retrospectively in a consecutive series of 52 patients (mean follow-up, 18.6 ± 11.7 mos) and 74 control subjects. The cumulative 2-year success (intraocular pressure [IOP] P = 0.01, Wilcoxon test). The 5-FU group had a mean postoperative IOP of 12.5 ± 4.6 mmHg versus 17.4 ± 5.7 mmHg in the control group at 2-year follow-up ( P = 0.015, t test). Antiglaucoma medications were required in 5.8% of patients in the 5-FU group and in 41.9% of controls within 2 years (P
On a nonlinear theory of plates and shells including consistent and inconsistent kinematics and the finite element method

Abstract A nonlinear theory of plates and shells for thick and thin models accounting for consistent and inconsistent kinematical approximations is presented in general curvilinear tensorial form. The incremental shell governing equations for the finite element formulation of boundary value problems for finite strains and large deformations are derived employing the incremental virtual work principle defined in a Lagrangian description. Sample problems are investigated numerically employing a hyperelastic material model for which both general and specific forms are introduced. Finite element solutions of thick and thin plate and shell problems are obtained by employing lower and higher order displacement models and are compared with results deduced from application of the finite element method based on exact equations of continuum mechanics. It is found that the kinematical theories, which are based on one general formulation, adequately predict displacements and normal stresses. However, major discrepancies arise in the shear stress distributions at finite strains when exact and lower order theories are compared. Finally, it is noted that the consistent kinematical theory described by a cubic variation of in-plane and transverse displacements through the thickness coordinate yields the most accurate and meaningful solutions. Furthermore, it is shown that higher order kinematical theories become significant in the analysis of thick structures.
Aeolian Processes on Venus

In this pre-Magellan review of aeolian processes on Venus we show that the average rate of resurfacing is less than 2 to 4 km/Ga, based on the impact crater size frequency distribution derived from Venera observations, reasonable values of the impact flux, and the assumption of steady state conditions between crater production and obliteration. Viscous relaxation of crater topography, burial by volcanic deposits, tectonic disruption, chemical and mechanical weathering and erosion, and accumulation of windblown sediments probably all contribute to resurfacing. Based on the rate of disappearance of radar-bright haloes around impact craters, the rate of removal of blocky surfaces has been estimated to be about 10−2 km/Ga. Pioneer-Venus altimetry data show that the average relative permittivity (at 17 cm radar wavelength) of the surface is too high for exposure of soils ⩾ 10 cm deep, except for ~5% of the planet located primarily in tessarae terrains. The tectonically disrupted tessarae terrains may be sites of soil generation caused by tectonic disruption of bedrock and the presence of relatively steep slopes, or they may be terrains that serve as traps for windblown material. The overall impression is that Venus is a geologically active planet, but one dominated by volcanism and tectonism. On the other hand, theoretical considerations and experimental data on weathering and transport of surface materials suggest rather different conditions. Thermochemical arguments have been advanced that show: (1) CO2 and SO2 incorporate into weathering products at high elevation, (2) transport of weathered material by the wind to lower-elevation plains, and (3) re-equilibration of weathered material, releasing both CO2 and SO2. In addition, kinetic data suggest a rate of anhydrite formation of 1 km/Ga, a value comparable to the soil erosion rate on Mars, a planet with an active aeolian environment. Experiments and theoretical studies of aeolian processes show that measured surface winds are capable of moving sand and silt on Venus. Assuming that there is a ready sand supply, the flux could be as high as 2.5 × 10−5 g/cm/s, a value comparable to desert terrains on Earth. In an active aeolian abrasion environment, sand grains could have lifetimes <103 years. In addition, comminuted debris may be cold-welded to surfaces at the same time as abrasion is occurring. Magellan altimetry and SAR observations should allow assessment of which model for venusian surface modification (active vs. inactive surficial processes) is correct, given the global coverage, high spatial resolution, the calibrated nature of the data, and the potential during extended missions of acquiring multiple SAR views of the surface.
A new look at stable isotope thermometry

Interdiffusion between coexisting minerals affects all rocks and causes resetting and discordance of stable isotope geothermometers that is commonly observed in slowly cooled igneous and metamorphic rocks. The Fast Grain Boundary (FGB) model describes the stable isotope fractionations and intracrystalline zonation which result from closed system interdiffusion (Eiler et al., 1991, 1992). This model assumes that grain boundary diffusion is much faster than volume diffusion, and it accounts for exchange among all minerals in a rock. Previous models of closure temperature violate mass balance restrictions and will be inaccurate in most rocks. Modeling results are described for amphibolites and hornblende granites and gneisses; biotite granites, schists, and gneisses; pelitic and semi-pelitic rocks; garnet peridotites; anorthosites, gabbros, pyroxenites, and related rocks; and calc-silicate rocks. Examples of mineral pairs and specific rock types that allow accurate stable isotope thermometry include plagioclase-pyroxene in pyroxene bearing anorthosites and garnet-quartz in garnetiferous quartzites. In contrast, the same mineral pairs in related rocks such as pyroxenites and pelitic schists will exhibit reset apparent temperatures. Closed-system processes are capable of producing a variety of patterns of stable isotope resetting, discordance, mineral zonation, and fractionation reversals. Examples include large reversals of quartz-feldspar fractionations in micaceous rocks, and oscillatory zonation in feldspar from some quartz-rich rocks. These results permit reinterpretation of many studies of stable isotope thermometry, speedometry, and retrograde alteration history. FGB modeling of mineral zonation provides an important new guide to applying recently developed micro-analytical tools to slowly cooled rocks. Application of the FGB model to quartzo-feldspathic gneisses from the Adirondack Mountains, New York, demonstrates the usefulness of diffusion modeling in discriminating closed-system, diffusion controlled retrogression from open-system retrogression, and illustrates the possible importance of incorporating the effect of water activity on mineral diffusivity.
Cytological events leading to the formation of the two-cell stage in the rabbit: association of the maternally and paternally derived genomes.

The cytological transformations leading to the establishment of the two-cell stage in the rabbit have been studied with techniques of light and electron microscopy. Subsequent to their migration the male and female pronuclei become centrally located and juxtaposed. Each pronucleas appears to be nearly identical in size and in structure and contains a fibrous nucleoplasm in which fine-textured and granular aggregations are embedded. Later the pronuclei become closely apposed and their proximal surfaces flatten and become highly convoluted. Along the proximal margin of the pronuclear envelopes small vesicular structures are produced. They are filled with a flocculent material and appear to be budded-off into the cytoplasm. During further morphogenesis, the pronuclei produce an extensive array of projections which interdigitate with one another to form complex configurations. Concomitantly, the blebbing activity of the pronuclear envelopes ceases and the chromatin condenses into large reticular aggregations, primarily in the region where the pronuclei are intimately associated. Association of the maternal and paternal genomes is effected when the two pronuclear envelopes break down at widely spaced intervals leaving regions of intact double-membrane structures (pronuclear envelope). Microtubules (spindle) are associated with the condensed chromatin and course through the disrupted regions of the pronuclear envelope. The two groups of chromosomes move together and assume positions on the first cleavage spindle. Thus, in the rabbit, there is an absence of a zygote nucleus.
Assessment of middle class youth at-risk to dropout: School, psychological and family correlates

Abstract High school dropout among middle class, high achieving and majority youth is on the increase. Little research exists that specifically identifies the at-risk characteristics of these youth. Empirical evidence concerning the reasons for school dropout, academic, psychological, and family patterns of 200 middle class dropout youth are presented. Implications for interventions are discussed.
Material properties and residual stress in the stage 12 chick heart during cardiac looping.

During the morphogenetic process of cardiac looping, the initially straight cardiac tube bends and twists into a curved tube. The biophysical mechanisms that drive looping remain unknown, but the process clearly involves mechanical forces. Hence, it is important to determine mechanical properties of the early heart, which is a muscle-wrapped tube consisting primarily of a thin outer layer of myocardium surrounding a thick extracellular matrix compartment known as cardiac jelly. In this work, we used microindentation experiments and finite element modeling, combined with an inverse computational method, to determine constitutive relations for the myocardium and cardiac jelly at the outer curvature of stage 12 chick hearts. Material coefficients for exponential strain-energy density functions were found by fitting force-displacement and surface displacement data near the indenter. Residual stress in the myocardium also was estimated. These results should be useful for computational models of the looping heart.
Chemical studies of the satellite cells of the squid giant nerve fiber.

Abstract The respiration of squid giant nerve fibers and of the satellite (Schwann) cell layer surrounding the axon surface membrane has been measured by a sheath-slitting technique, using a modification of the Scholander micro-respirometers. Estimation of the contribution of the satellite cells was facilitated by determination of wet and dry weights, total protein and collagen content of intact fibers, slit sheaths and dissected periaxonal tissue. The oxygen consumption averaged 13.5, 7.9 and 7.8 mm3 O2/mg dry weight/hour for slit sheaths, intact fibers and periaxonal tissue, respectively, all calculated on the collagen-free basis. The sheath cells are responsible for about 45 per cent of the respiration of the intact fiber though contributing only about 27 per cent of the dry weight. Some evidence for the presence of a factor or co-factor in sea water, not present in saline media artificially prepared from pure chemicals, is described. Dinitrophenol and azide have little effect on intact fibers, but strongly inhibit the respiration of slit sheaths in 10−5 to 10−4 M concentration. The potassium concentration remains high in slit sheaths as compared with intact fibers and periaxonal tissue even after several hours of shaking. DNP reduces the concentration in slit sheaths substantially.
Phosphorylation of the G Protein γ12 Subunit Regulates Effector Specificity

Although the G protein betagamma dimer is an important mediator in cell signaling, the mechanisms regulating its activity have not been widely investigated. The gamma12 subunit is a known substrate for protein kinase C, suggesting phosphorylation as a potential regulatory mechanism. Therefore, recombinant beta1 gamma12 dimers were overexpressed using the baculovirus/Sf9 insect cell system, purified, and phosphorylated stoichiometrically with protein kinase C alpha. Their ability to support coupling of the Gi1 alpha subunit to the A1 adenosine receptor and to activate type II adenylyl cyclase or phospholipase C-beta was examined. Phosphorylation of the beta1 gamma12 dimer increased its potency in the receptor coupling assay from 6.4 to 1 nM, changed the Kact for stimulation of type II adenylyl cyclase from 14 to 37 nM, and decreased its maximal efficacy by 50%. In contrast, phosphorylation of the dimer had no effect on its ability to activate phospholipase C-beta. The native beta1gamma10 dimer, which has 4 similar amino acids in the phosphorylation site at the N terminus, was not phosphorylated by protein kinase C alpha. Creation of a phosphorylation site in the N terminus of the protein (Gly4 --> Lys) resulted in a beta1 gamma10G4K dimer which could be phosphorylated. The activities of this beta gamma dimer were similar to those of the phosphorylated beta1 gamma12 dimer. Thus, phosphorylation of the beta1 gamma12 dimer on the gamma subunit with protein kinase C alpha regulates its activity in an effector-specific fashion. Because the gamma12 subunit is widely expressed, phosphorylation may be an important mechanism for integration of the multiple signals generated by receptor activation.
Synthesis of 2,2-Disubstituted Pyrrolidine-4-carboxylic Acid Derivatives and Their Incorporation into β-Peptide Oligomers

We have recently shown that members of a new class of β-peptides, containing 2,2-disubstituted pyrrolidine-4-carboxylic acid residues, display discrete conformational preferences despite the impossibility of internal hydrogen bonding (Huck et al. J. Am. Chem. Soc. 2003, 125, 9035). Here we describe the synthesis of a variety of 2,2-disubstituted pyrrolidine-4-carboxylic derivatives that bear a diverse set of side chains and protecting groups suitable for oligomer synthesis. In addition, we discuss coupling methods for construction of oligomers in solution and on solid phase. Non-hydrogen bonded foldamers such as those generated from 2,2-disubstituted pyrrolidine-4-carboxylic acids may be useful in biomedical applications because the low intrinsic polarity of their backbones may promote bioavailability.
Truth-table look-up processing: number representation, multilevel coding, and logical minimization

The need for ultra-high-speed computing for a variety of modern processing problems has generated new interest in using truth-table look-up techniques. Further, due to the frequently parallel nature of these processing problems, optical systems appear to be promising for these applications. The basic principles of truth-table look-up processing are reviewed in this paper. The issues of number representation, multilevel coding, and logical minimiza­ tion are discussed. Example fixed-radix and residue number representations are given with and without multilevel coding. Logical reduction techniques are discussed with examples. A comparison of the number of truth-table entries needed for 16-bit full-precision addition and multiplication is given, illustrating the advantage of the multilevel coded residue number representation.
Equipment Prices, Human Capital and Economic Growth

Abstract This paper presents a multisectoral model of economic growth in which endogenous technological progress is embodied in new equipment capital. The difference in the intensity of use of human capital across sectors creates aggregate dynamic non-convexities, and hence the model may generate multiple balanced growth paths. Under standard parameter values, our model can explain the observed correlations, found for a pool of countries, between investment rates in equipment capital and income growth, on the one hand, and between the rate of decline in equipment prices and income growth, on the other. The model is then used to study the effectiveness of two public policies that have been widely implemented to promote economic growth: An equipment investment tax credit, and a tax incentive to human capital accumulation. Our results indicate that both policies have positive effects on equipment investment and on long-run growth.
Kinetics of the actomysin ATPase Four or six states

Abstract Tesi et al. [(1990) FEBS Lett. 260, 299/2-232] use a misinterpretation of the four-state controversy as a springboard to this paper. The authors give no data to characterize the proteins, making it impossible to compare the proteins with those from other laboratories. The analysis is flawed by the authors' failure to verify that the steady state rates obtained compared reasonably well with published rates. Although a four-state model may be a satisfactory approximation for certain limited purposes, it is not a sufficient basis for a complete analysis of the actomyosin system.
The impact of ada on the selection process: Applicant and organizational issues

Abstract In this article we adopt a multiple stakeholder approach to examine the impact of ADA on the selection process. Specifically, we dissect the selection process into its component steps and for each step identify the potential impediments to hiring the disabled. In addition, we discuss the intended effects of the ADA, and its implications for organizations and job applicants. We also offer suggestions for research on ADA and selection in order to stimulate additional research on the topic.
Procedures for processing thermal images using low-cost microbolometer cameras for small unmanned aerial systems

Remote sensing data using thermal-infrared (TIR) cameras can be very helpful for many applications including agriculture and thermal refugia for fish habitat. Small unmanned aerial vehicles (UAS) can be efficient platforms for providing high-resolution thermal imagery at a low-cost; however most thermal cameras used for remote sensing are cooled systems and can be very large, expensive, and consume large amounts of power. Because of these constraints they are not easily integrated with small UAS. For surveillance and military applications, microbolometer thermal cameras are widely used on UAS because they are smaller, less expensive and consume less power than cooled thermal cameras. However, mi-crobolometer thermal cameras are not as sensitive and accurate as cooled systems. Also, many are not calibrated and only measure relative temperature. This presents a challenge when microbolometer thermal cameras are used for scientific and ecological applications: absolute surface temperature is necessary for these applications. This paper presents procedures that can be followed to convert the raw images from a microbolometer camera to accurately represent surface temperature (without compensating for emissivity). The steps needed for this include preparing the images for orthoretification, geometric calibration, orthorectification, and correction for external disturbances.
Relative Effectiveness of DRO and Self-Monitoring in a General Education Classroom

This manuscript describes a research project designed to examine the relative effectiveness of a two non-function-based interventions (differential reinforcement of other behavior and self- monitoring) for decreasing problem behavior in a general education classroom for three students whose problem behaviors were hypothesized to be functionally related to peer attention. When examined with three typically developing students engaging in high frequency problem behaviors, results indicated that both non-function based interventions decreased problem behavior similarly.
Conflicting Shareholder Interests An Empirical Analysis of Fair Price Provisions

This study of 258 corporations provides an assessment of the impact of institu-tional investor stockholding on fair price adoption decisions. In addition, the influence of board composition, board leadership, and the interaction between these two governance attributes on such decisions is examined. The results of analyses suggest that only institutional stockholding plays a significant role.
Do early birds get the returns? An empirical investigation of early‐mover advantages in acquisitions

We explore whether pioneering advantages exist for early-mover acquirers in industry acquisition waves by examining both combined (target and acquirer) and acquirer stock returns. Combined abnormal returns are higher for acquisitions that occur at the beginning of acquisition waves. However, for acquirers' returns, only strategic pioneers—those acting in manners consistent with having superior information—capture significant advantages. Specifically, early-mover acquirers who realize superior stock returns are those that conduct acquisitions in related industries, during industry expansionary phases, and finance their acquisitions as financial theory suggests they should when they possess an informational advantage—with cash. Our findings extend the first-mover literature to corporate practices and link these practices to acquisition returns. Copyright © 2004 John Wiley & Sons, Ltd.
Theory of detonation stability

The theory of the hydrodynamic stability of steady one-dimensional detonation waves, having finite rates of chemical reactions and neglecting other transport properties, is reviewed. The discussion includes (1) the general theory and its application to certain idealized detonations, (2) the stability of the square-wave detonation model, and (3) the application of acousticray tracing to steady detonations and its relation to stability. It is concluded that at present only the considerations discussed in (1) have been fruitful in differentiating stable from unstable detonations. The problem of the application of this theory to an arbitrary system is discussed. The square-wave calculations appear to indicate that such detonations are generally unstable, a conclusion consistent with the trend observed in (1) for large activation energy, but the validity of this conclusion remains in doubt. The ray analysis of (3) appears to lend added physical insight into the short-wavelength asymptotic analysis of (1), but does not otherwise add new information with respect to stability.
Glass inclusions as samples of early magmatic liquid: determinative method and application to a south atlantic basalt

Abstract Silicate melt inclusions in phenocrysts are not directly representative of trapped magmatic liquid because chemical interaction between inclusions and host crystals usually occurs after melt entrapment. However, if more than one phenocryst type in a suite of rocks contains melt inclusions, the original trapped-liquid composition can be accurately fixed by the intersection of host-mineral fractionation lines in a triangular oxide plot of inclusion analyses. When plotted on a CaO—MgO—Al 2 O 3 triangular diagram, analyses of inclusions in plagioclase, olivine, and clinopyroxene from a basalt dredged off Bouvet Island fall along crystal fractionation lines that intersect at a single point. This point represents an initial trapped liquid composition rich in CaO and MgO, and low in TiO 2 and total alkalies. The composition is transitional between tholeiite and basaltic komatiite, and may be indicative of extensive melting of clinopyroxene in the mantle.
Anatomical adaptations of aquatic mammals

This special issue of the Anatomical Record explores many of the anatomical adaptations exhibited by aquatic mammals that enable life in the water. Anatomical observations on a range of fossil and living marine and freshwater mammals are presented, including sirenians (manatees and dugongs), cetaceans (both baleen whales and toothed whales, including dolphins and porpoises), pinnipeds (seals, sea lions, and walruses), the sea otter, and the pygmy hippopotamus. A range of anatomical systems are covered in this issue, including the external form (integument, tail shape), nervous system (eye, ear, brain), musculoskeletal systems (cranium, mandible, hyoid, vertebral column, flipper/forelimb), digestive tract (teeth/tusks/baleen, tongue, stomach), and respiratory tract (larynx). Emphasis is placed on exploring anatomical function in the context of aquatic life. The following topics are addressed: evolution, sound production, sound reception, feeding, locomotion, buoyancy control, thermoregulation, cognition, and behavior. A variety of approaches and techniques are used to examine and characterize these adaptations, ranging from dissection, to histology, to electron microscopy, to two-dimensional (2D) and 3D computerized tomography, to experimental field tests of function. The articles in this issue are a blend of literature review and new, hypothesis-driven anatomical research, which highlight the special nature of anatomical form and function in aquatic mammals that enables their exquisite adaptation for life in such a challenging environment.
Increased Rates of Morbidity, Mortality, and Charges for Hospitalized Children With Public or No Health Insurance as Compared With Children With Private Insurance in Colorado and the United States

BACKGROUND. There has been a gradual decrease in the proportion of children covered by private health insurance in Colorado and the United States with a commensurate increase in those with public insurance or having no insurance which may impact access to care and outcomes. OBJECTIVE. The purpose of this work was to determine whether children with public or no health insurance have differences in hospital admission rates, morbidity, mortality, and/or charges that might be improved if standards of primary care comparable to those of children with private insurance could be achieved. METHODS. We conducted a retrospective comparison of hospitalization-related outcomes for children RESULTS. Compared with those with private insurance, children in Colorado and the United States with public or no insurance have significantly higher rates of total hospital admission, as well as admission for chronic illness, asthma, diabetes, vaccine-preventable disease, psychiatric disease, and ruptured appendix. These children have higher mortality rates, higher severity of illness, are more likely to be admitted through the emergency department and have significantly higher hospital charges per insured child. Higher hospitalization rates occur in children who are nonwhite and/or Hispanic and those who are younger. If children with public or no health insurance in the United States in 2000 had the same hospitalization outcomes as children with private insurance, $5.3 billion in hospital charges could have been saved. CONCLUSIONS. There is an opportunity to achieve improved health outcomes and decreased hospitalization costs for children with public or no health insurance if private insurance standards of health care could be achieved for all US children.
Determination of weak Fe+–L bond energies (L = Ar, Kr, Xe, N2, and co2) by ligand exchange reactions and collision-induced dissociation

Abstract Guided-ion beam mass spectrometry is used to study the ligand exchange and collision induced dissociation reactions of Fe+(N2) with Ar, Kr, Xe, CO2, and CD4 and Fe+(CO2) with Kr, Xe, and N2 as a function of kinetic energy. Analysis of the energy dependent cross sections provides threshold energies for both types of reactions. These thresholds can be converted to the following 0 K bond dissociation energies: D0(Fe+–Ar) = 0.11 ± 0.08 eV, D0(Fe+–Kr) = 0.31 ± 0.07 eV, D0(Fe+–Xe) = 0.44 ± 0.06 eV, D0(Fe+–N2) = 0.55 ± 0.04 eV, and D0(Fe+–CO2) = 0.62 ± 0.04 eV. Our results are compared with experimental and theoretical values found in the literature. These comparisons suggest that Fe+(CO2) has a linear structure in agreement with theoretical calculations.
Correlation of changes in cardiac calcium channels with hemodynamics in Syrian hamster cardiomyopathy and heart failure.

We compared hemodynamics with [3H]nitrendipine (calcium channel) binding to cardiac membranes from Bio 14.6 cardiomyopathic Syrian hamsters at 4 and 10 months with their F1B controls. A 50% increase in the number (Bmax) of nitrendipine binding sites (calcium channels) was seen only in the 4 month old myopathic vs controls (Bmax = 4±11 vs 309±10 fmol/mg prot with no change in affinity (KD) (KD = .65±12 vs .75±14nM), while no differences in Bmax or KD were seen at 10 months (Bmax = 375±9 vs 362±7 fmol/mg prot/KD = .82±18 vs .89±17 nM) myopathic vs control respectively. Hemodynamic studies revealed no significant differences in cardiac output, cardiac index, stroke volume, heart rate, mean arterial pressure, peripheral resistance, body weight, heart weight at 4 months, but a significant decrease in peripheral resistance (1120±360 vs 2080±240) increase in body weight (118±2 vs 94±2 grams) and heart weight (97±5 vs 78±2gms/100gms body weight) in 10 month myopathic vs control animals. We conclude that the onset of cardiomyopathy at 4 months is associated with a selective increase in calcium channel binding sites and heart failure at 10 months is associated with a relative decrease in these sites.
Imbeddings and bounds for functions with Lq-Laplacians☆

Abstract Spaces of locally integrable functions on R n that vanish at ∞ and whose gradient and Laplacian are in L p ( R n ; R n ) , L q ( R n ) respectively are defined. A representation theorem for such functions is described and properties of the fundamental solution of the modified Laplacian operator are used to prove L r and supremum norm inequalities when n = 3 . Imbedding results for these spaces into L r ( R 3 ) and C 0 ( R 3 ) when 1 ⩽ p 3 are described. The case p = q = 2 yields a reproducing kernel Hilbert space of functions on R 3 . Some different estimates for solutions of the finite mass and energy solutions of Poissonʼs equation on R 3 are found using these results.
Differential and derivative polarography for continuous analysis in a flow system: application to alloy dissolution

Abstract A differential and/or derivative polarographic circuit and cells were designed for continuous chemical analysis in a flowing system while in-situ microscopic observations of the surface of a substrate could be made. The technique was applied to the analysis of the dissolution products of anodically polarized CuNi alloys. Individual current-potential relations at constant current were obtained for both copper and nickel for two CuNi alloys of different compositions.
Healthy female carriers of a gene for the Alport syndrome: Importance for genetic counseling

Of 305 female obligatory carriers of a gene for the Alport syndrome identified in the literature, 37 (12.1%) had no clinical or laboratory signs or symptoms (renal, audiometric, ophthalmological) of disease. The prevalence of unaffected female obligatory carriers appeared not to vary according to age or to the severity of the illness in male members of any pedigree. Normal clinical or laboratory data for any female liable for the Alport syndrome must thus be interpreted with caution.
Determinants for outcome of balloon valvuloplasty for severe pulmonary stenosis in neonates and infants up to six months of age

Abstract In older children, many reports have shown that balloon valvuloplasty for valvular pulmonary stenosis is a safe and effective alternative to surgical valvulotomy, and therefore is considered to be the procedure of choice. 1–5 However, in young infants and neonates, the results of balloon valvuloplasty are less satisfactory, with reported failure rates ranging from 17 to 45%. 6–10 The lower success rate may be related to the smaller size of the patients, but also to differences in anatomy of the right ventricle and its valves, and in hemodynamics when compared with those of older children. In addition to the lower success rate, complications of the procedure are more frequent in this age group, 1,7,9 including femoral vein thrombosis, paradoxic emboli and perforation of the myocardium. In this article, we report the experience of 3 Dutch pediatric cardiology centers with nonelective balloon valvuloplasty in children aged