cssi/SciSciGPT-SciSciNet huggingface dataset:
Competition for market share in the presence of strategic invisible assets: The US automobile market, 1971–1981

Abstract The effect of marketing actions on business performance depends on a firm's asset endowments. These endowments position a firm to exploit market opportunities and to create comparative advantage. Just as strategies developed in the absence of an appreciation of the firm's assets are unlikely to prove successful, so are studies of marketing mix efforts. However, analyzing the effect of marketing variables on performance is complicated by the fact that some of a firm's most important assets are “invisible,” i.e., unobservable. We advance an econometric modeling approach for assessing marketing mix effects in the presence of differing asset endow ments, some of which may be unobservable, and apply it empirically to study the competitive situation in the US automobile market in the 1970s. The analysis highlights the importance of both firm-specific and country-specific invisible assets in influencing marketing mix effects and business performance.
The accumulation of cadmium by the plaice, Pleuronectes platessa L. and the thornback ray, Raja clavata L

The accumulation of cadmium (115mCd) from both food and sea water by the plaice, Pleuronectes platessa L., and thornback ray, Raja clavata L., has been studied in relation to their measured cadmium concentrations. Plaice accumulated cadmium from sea water at a faster rate than rays, although the concentrations factors attained by both species as a result of such direct accumulation were very low. Both species retained cadmium from food and accumulated it in the liver, the rays relatively more than the plaice. From analyses of North Sea fish, some evidence was found for a positive linear relation between the concentrations of cadmium in plaice liver and age, but not weight, of the fish.
Abnormal granulocyte feedback regulation of colony forming and colony stimulating activity-producing cells from patients with chronic myelogenous leukemia☆

Colony inhibiting activity (CIA), which can be obtained from human polymorphonuclear neutrophil leukocytes (PMN), reduces the numbers of bone marrow and blood (density < 1.070 g/cm3) cells which can spontaneously proliferate in vitro to form colonies and clusters. However, PMN from patients with chronic myelogenous leukemia (CML) were quantitatively deficient in CIA regardless of the patient's clinical status or in vitro growth patterns. Even greater differences in (CIA) between normal and CML-PMN were unmasked by high speed centrifugation of PMN-extracts. Potency of CIA from normal PMN could be enhanced by removal of material pelleted after centrifugation at 160,000 g. Removal of the pellet also decreased the 37°C temperature sensitivity of CIA. CIA from CML-PMN was not enhanced by this procedure. CIA obtained from CML-PMN had the same site of action as that from normal PMN. Although not species specific, CML-CIA was specific in its non-toxic action on the Colony Stimulating Activity (CSA)-producing cell; both CFU-c and cell-free CSA molecules were not affected. A further defect was noted in that target cells (density < 1.070 g/cm3) from patients with CML were less sensitive than normal targets to inhibition with low concentrations of CIA from normal PMN. However, high concentrations of CIA were as active against CML as against normal targets. The reasons for the decreased sensitivity of CML targets are discussed. These negative feedback abnormalities in vitro may partially explain granulocytic hyperplasia associated with CML.
IN VITRO CONTRACTURE OF PSEUDOPREGNANT UTERINE MUSCLE CONTRASTED WITH ESTROUS MOTILITY

KEYE (1923) in Corner's laboratory observed the behavior of isolatedstrips of sow's uterine muscle at different stages of the cycle suspended in physiological saline solution. His graphs show that during the estrous phase, immediately before ovulation, the motility pattern is characterized by uniform contractions of high amplitude, occurring at intervals of 1 to 2 per minute. Almost at once after rupture of the follicles the spontaneous contractions begin to diminish in amplitude and to occur more frequently. As the organization of the corpus luteum progresses, the motility pattern changes from day to day until day 12 or 13 of the sow's cycle, when the embryos complete their journey through the reproductive canal to their sites of implantation and begin to attach themselves. At this time the motility pattern of the isolated muscle strip is characterized by very frequent spontaneous contractions (4 to 8 per minute) of very slight amplitude, so that the kymographic tracing becomes almost level.
Factors influencing seasonal absconding in colonies of the African honey bee, Apis mellifera scutellata

This study investigated the effects of colony growth and development, food storage, foraging activity and weather on the migration behavior of African honey bees in the Okavango River Delta, Botswana. Four observation colonies were studied during the honey bee migration season (November–May), at which time the availability of blooming species was reduced. Two of the colonies (colonies 1 & 2) migrated during the study period, while the remaining two (colonies 3 & 4) did not. During the 4–6 weeks preceding the onset of migration preparations, colonies 1 & 2 exhibited increasing population sizes, high levels of brood production with low brood mortality, relatively large stores of food, and increasing mass. In contrast, the populations of colonies 3 & 4 did not increase, brood-rearing activity was erratic and lower, brood mortality was higher, food stores became depleted and colony mass declined. Both colonies 3 & 4 ceased rearing brood, and colony 3 died of starvation. Colony foraging activity was examined by monitoring waggle-dance activity 2–3 days each week. For 4–6 weeks before the onset of migration in colonies 1 & 2, daily foraging areas and mean daily foraging distances became increasingly large and variable. Colonies 3 & 4 exhibited foraging patterns similar to those observed for colonies 1 & 2 preceding migration. There was no clear association between 7 weather parameters examined and migration behavior. These data suggest that migration is influenced by an interaction of intra-colony demographics, food reserves and foraging patterns. Migration may be feasible only for those colonies that possess (1) a population of appropriate size and age structure to compensate for the natural attrition of older workers during the emigration process, and (2) sufficient food reserves for long-distance travel and the establishment of a new nest. Changing foraging patterns may reflect a deteriorating foraging environment, which may trigger the onset of migration preparations, provided that colony demographics and food reserves are conducive. Colonies that show decreased brood production, higher brood mortality and reduced food stores may be incapable of migrating, even when experiencing deteriorating foraging conditions. Rather, such colonies may have a greater chance of survival if they attempt to persist in a given area.
Sublethal effects of the antibiotic tylosin on estuarine benthic microalgal communities

Pharmaceuticals are common chemical contaminants in estuaries receiving effluent from wastewater and sewage treatment facilities. The purpose of this research was to examine benthic microalgal (BMA) community responses to sublethal exposures to tylosin, a common and environmentally persistent antibiotic. Bioassays, using concentrations of 0.011-218 μmol tylosin l(-1), were performed on intertidal muddy sediments from North Inlet Estuary, SC. Exposure to tylosin resulted in a reduction in total BMA biomass and primary productivity. Furthermore, exposure seemed to retard diatom growth while having a minimal effect on cyanobacteria biomass. Estuarine systems receiving chronic inputs of trace concentrations of tylosin, as well as other antibiotics, may experience significant reductions in BMA biomass and primary productivity. Given the well-documented role of BMA in the trophodynamics of estuaries, these impacts will likely be manifested in higher trophic levels with possible impairments of the structure and function of these sensitive systems.
Can Credence Advertising Effects Be Isolated? Can They Be Negative?: Evidence from Pharmaceuticals

We explore the relative impact of informative versus the credence effects of direct-to-consumer advertising in the market for prescription drugs. In particular, we examine how advertising for statin medications affects the delay between diagnosis and pharmacological treatment for patients with elevated cholesterol, as well as the time between treatment initiation and therapy switching. Duration models of delay to treatment indicate that over some ranges, advertising increases the likelihood of treatment, while over other ranges greater advertising is associated with lower likelihood of treatment. Results for the switching behavior models indicate that on net, advertising tends to both discourage switching between drugs and encourage therapy continuation. However, the component of the advertising that represents credence effects is generally positive, which indicates that as patients' spell of drug usage lengthens, the Food and Drug Administration-required warnings in advertisements induce consumers to switch away from the pharmaceuticals they are using.
Plasma ghrelin concentrations of beef cattle consuming a similar amount of dietary energy supplied by different ingredients.

Previous research demonstrated increased plasma ghrelin concentrations in beef cattle when intake of a high-grain diet was restricted. Two experiments were conducted to determine whether differences in DMI influenced plasma ghrelin concentrations when energy intake was similar but cattle were in either an anabolic or a catabolic state. In Exp. 1, five steers (BW = 592.6 +/- 9.3 kg) were offered dietary treatments of 1) 50:50 hay:concentrate (HY) to meet the NE(m) requirement and were supplied an additional 3.4 Mcal of NE(g) daily, 2) or a diet composed of 10:90 hay:concentrate but were limit-fed to achieve an energy intake similar to that of the HY steers (LFC). The LFC treatment met the NE(m) requirement of each steer and supplied 3.6 Mcal of NE(g) daily. The experiment was conducted as a crossover design composed of 2 21-d periods. In the first period, 2 steers were assigned to the HY treatment and 3 steers were assigned to the LFC treatment. On d 21 after initiation of the dietary treatment, serial blood samples were collected via indwelling jugular catheter, using periods of frequent sampling in which samples were collected at 15-min intervals. The periods of frequent sampling were spread throughout the beginning, middle, and end of the 12-h feeding interval. After the first period, steers were weighed, dietary treatments were switched between steer groups, and intake amounts were recalculated on the basis of the first-period ending BW. The second-period adaptation and sampling were repeated as described for the first period. Plasma samples were assayed for ghrelin, insulin, GH, and NEFA concentrations. Experiment 2 was conducted using the same methodology as Exp. 1, except that steers were in a catabolic state. Five steers (BW = 718.3 +/- 12.8 kg) were offered the HY or LFC diet at an amount that would supply 80% of the NE(m) required to maintain BW. For Exp. 1, energy intake was sufficient to result in similar (P = 0.14) BW gains between treatment groups. Experiment 2 energy intake resulted in a loss of BW that was similar (P = 0.66) between treatment groups. In both experiments, the decreased energy density of the HY diet resulted in greater (P or = 0.44) when energy intakes were similar despite differences in DMI between HY and LFC steers. Plasma NEFA concentrations were similar (P > or = 0.45) between treatment groups in an anabolic state but tended to differ (P = 0.09) as a result of treatment for cattle in the catabolic state. These data are consistent with the hypothesis that quantity of DMI does not influence plasma ghrelin concentrations of steers when energy intake is similar.
The formation of oxalate from hydroxypyruvate, serine, glycolate and glyoxylate in the rat.

Abstract [ 14 C]Oxalate was found in the urine of fasted male Wistar rats fed l- [ 14 C 3 ]-serine, dl -[ 14 V 2 ]serine, [ 14 C 1 ]ethanolamine, [ 14 C 1 ]hydroxypyruvate, [ 14 C 3 ]hydroxypyruvate, [ 14 C 1 ]glycolate or [ 14 C 2 ]glyxylate, [ 14 C 1 ]Hydroxypyrusvate and [ 14 C 1 ]ethanolamine were the least effective precursors of [ 14 C]oxalate. 20% of the [ 14 C 1 ]serine and [ 14 C 3 ]serine administered was recovered as 14 CO 2 , while less then 4% was metabolized by pathways known to contribute to oxalate synthesis. Oxalate synthesis from serine involved both the transamination to hydroxypyruvate and the conversion to glycine, but not decarboxylation to ethanolamine. The oxidation of [ 14 C 2 ]glyoxylate to [ 14 C]oxlate inhibited by hydroxypyruvate, but the oxidation of [ 14 C 1 ]glycolate to [ 14 C]oxlate was not significantly altered. [ 14 C]Glycolaldehyde, [ 14 C]glycolate, [ 14 C]glyoxylate and [ 14 C]oxalate were recovered in the urine of rats administratered [ 14 C 3 ]hydroxypyruvate. This is consistent with the oxidation of hydroxypyruvate via glycolaldehyde → glycolate → glyoxylate → oxalate and is identical to the metabolic pathway for the oxidation of ethylene glycol to oxalate. However, the major metabolic intermediate recovered from [ 14 C 3 ]hydroxypyruvate was [ 14 C]glyoxylate rather than [ 14 C]glycolate, suggesting that an laternate pathway is contributing to the oxidation of hydroxypyruvate to oxalate in the rat.
Letting students be innovative! Using mini-grants to fund student-designed HIV/AIDS education

This article describes a project designed to use student leaders to increase the awareness of HIV/AIDS among college students. Student organizations apply for a competitive mini-grant that is used to increase their members' knowledge level about HIV/AIDS and increase the likelihood of individuals' practicing behaviors that would reduce the risk of transmission or contraction. Four student organizations receive funds to design a unique HIV/ AIDS prevention intervention that match its members' needs for a total of 126 individuals receiving HIV/AIDS education. An evaluation indicates positive behavioral intentions related to sexual communication and safer sex practices. Moreover, the majority of participants report the education received as relevant and applicable. The methods, intervention applications, and benefits to using an award competition to deliver HIV prevention education to college students in a nontraditional and innovative approach are detailed within this article.
Chiral Spin Traps. The Spin Trapping Chemistry of 5-Methyl-5-phenylpyrroline-N-oxide (MPPO)

Abstract The use of 5,5-dimethylpyrroline- N -oxide (DMPO) as a versatile spin trap was first published in this journal (E. G. Janzen and J. I.-P. Liu, J. Magn. Reson. 9, 510–512 (1973). In this paper, the general use of an improved DMPO-type spin trap, namely 5-methyl-5-phenylpyrroline- N -oxide (MPPO), is proposed. MPPO is more stable than DMPO and has an excellent shelf life. Commonly known artifacts of DMPO are not present in MPPO. The EPR spectra of MPPO spin adducts have the same patterns as DMPO spin adducts which users have become familiar with. The lifetimes of spin adducts are longer for MPPO than for DMPO and the rate constants of spin trapping are similar. An interesting additional feature is associated with the detection of two spin-adduct spectra in some cases. The major component is assigned to the trans addition product (with respect to the phenyl group) in the case of carbon-centered radicals. The minor component is assigned to the cis adduct. In the superoxide/peroxyl radical adduct, however, the reverse appears to be the case. Only one EPR spectrum is detected in the hydroxyl radical adduct of MPPO.
Near-wall velocity structures that drive turbulent transport from a line source at the wall

This work involves numerical experiments that were conducted in a turbulent channel flow using direct numerical simulation in conjunction with the tracking of thermal markers released from a single instantaneous line source at the wall of the channel. The simulations were conducted at Reτ = 300 and for different Prandtl number fluids (Pr = 0.1, 0.7, 6, 20, and 50), in order to investigate the physical mechanism of turbulent transport and the flow structures that promote turbulent transport. The behavior of these heat markers was observed in 12 locations ranging from 1 to 12 half-channel heights downstream from the source. In each of these locations the flow structures that carried thermal markers towards the channel center (i.e., those that transfer heat away from the wall) and flow structures that carried thermal markers towards the channel wall (i.e., those that transfer heat towards the wall) were identified and characterized as a function of the Prandtl number. The characteristic time and length scale...
On the least-squares method

Abstract It is shown that the theoretical basis of the general least-squares method is the bounded inverse theorem. This explains why the least-squares finite element method (LSFEM) within one mathematical/computational framework without any special treatment can provide numerical solutions for all types of partial differential equations. Error estimates of LSFEM for general and elliptic first-order systems of partial differential equations are established. As an example, the incompressible Stokes equations are considered. The principal part of the Stokes equations in the first-order velocity-pressure-vorticity formulation consists of two div-curl systems. This knowledge is employed to derive all permissible combinations of non-standard boundary conditions for the Stokes equations and to show that under these conditions the Stokes operator is bounded below in the full H1 sense, and hence the corresponding LSFEM is optimal. The numerical results are also given to support this conclusion.
Reflexive Reasoning with Multiple Instantiation in a Connectionist Reasoning System with a Type Hierarchy

Abstract We describe a hybrid knowledge representation and reasoning system that integrates a rule-based reasoner with a type hierarchy and can accommodate multiple dynamic instantiations of predicates. The system—which is an extension of the reasoner described in Shastri and Ajjanagadde (1990)maintains and propagates variable bindings using temporally synchronous (i.e. in-phase)firing of appropriate nodes, and can perform a broad class of reasoning with extreme efficiency. The type hierarchy allows the system to encode generic facts such as ‘cats prey on bird’ and rules such as ‘if x preys on y then y is scared of ’ and use them to infer that Tweety the canary is scared of Sylvester the cat. The system can also encode qualified rules such as ‘if an animate agent collides with a solid object then the agent gets hur’. The ability to accommodate multiple dynamic instantiations of any predicate allows the system to handle a much broader class of inferences, including those involving transitivity and bounded ...
Conjugated polyelectrolyte based real-time fluorescence assay for adenylate kinase.

Addition of adenosine 5'-triphosphate (ATP) to a solution of the anionic conjugated polyelectrolyte PPECO2 and copper(II) ion (Cu2+) recovers the Cu2+-quenched fluorescence of PPECO(2) to a significantly greater extent compared with the addition of adenosine 5'-diphosphate (ADP) or adenosine 5'-monophosphate (AMP) at the same concentration levels. Taking advantage of the differential response of the PPECO2-Cu2+ system to ATP, ADP and AMP, we have developed fluorescence turn-off and turn-on assays that monitor the catalytic activity of adenylate kinase (ADK) in the equilibrium transphosphorylation reaction (ATP + AMP 2ADP). The fluorescence turn-on and turn-off assays monitor the forward and reverse transphosphorylation reactions, respectively. The forward assay operates with ATP substrate present at the submillimolar concentration range and offers a straightforward and rapid detection of ADK catalytic activity with the enzyme present in the nanomolar range, in either end-point or real-time formats. The real-time fluorescence intensity from PPECO2 can be converted to substrate (ATP) concentration in the forward reaction assay by using an ex-situ calibration curve, allowing ADK catalyzed reaction rates and kinetic parameters to be determined. ADK activation by Mg2+ and inhibition by Ag+ and product are analyzed using the optimized assay system. Non-specific interactions are observed between the assay complex and other proteins, but the signal response to the ADK assay is demonstrated to mainly arise from the specific enzyme catalyzed transphosphorylation reaction.
Economics and Inequality in Schools.

(1988). Economics and inequality in schools. Theory Into Practice: Vol. 27, Civic Learning, pp. 282-287.
Local Rotor Winding Temperature Measurements for Large Turbine-Generator Fields

Accurate measurements of the temperature profiles in the rotor windings of 11 large turbine generators have been made during factory tests over the past 3 years. Up to 77 rotor thermocouples have been read through instrument slip rings during heat runs at loadings up to full-load field current. A new method to load the rotor during factory tests has been employed. Local temperature measurements are particularly important to the orderly development of highly rated conductor-cooled fields.
Rats can learn simultaneous four-drug discriminations in four-lever boxes

Rats were required to learn a four-drug discrimination in compartments containing four levers. The training drugs were phenobarbital 35 mg/kg, nicotine 0.8 mg/kg, fentanyl 0.04 mg/kg, and methylphenidate 5 mg/kg. Responding on a different lever was reinforced with 0.1 ml sweetened water under each drug condition. The experiment tested whether such four-drug discriminations could be learned, and whether the rate of acquisition and/or asymptotic accuracy of the discriminations would be increased in boxes where each lever was surrounded by a unique sensory environment created by special materials on the floors, walls, and ceiling in the vicinity of the lever (e.g., plastics, wire screens). Four different training compartments were employed. The required discriminations were learned by most rats. The use of unique decorations around each lever decreased the mean number of sessions before the appearance of discriminative control from 90 to 67. It also made asymptotic accuracy significantly higher in some sensory environments than in others. suggesting that animals “preferred” some environments. The training drugs were apparently not equally discriminable at the doses employed, as both sessions to criterion and asymptotic accuracy differed for the various drugs employed.
Meiofauna and the thiobios in the east flower garden brine seep

Special hydrodynamic-chemical conditions at the East Flower Garden brine seep have provided the opportunity to examine the community structure of the thiobios and the oxybiotic-thiobiotic boundary. The boundary between the thiobios, whose population maxima occur in sulfidedependent chemoclines and which presumably have an ecologic requirement for sulfide, and the oxybios, which occur in oxidized zones above the chemocline, is controlled by sulfide, not oxygen. The boundary, which may not be at zero sulfide, is determined by a time-concentration phenomenon based on a dynamic interplay of sulfide and oxygen supply rates and the biota's sulfide detoxification capabilities. In Gollum's Canyon, where oxygen is plentiful, the boundary is at 10–40 μg-atoms·l-1 sulfide. Total abundances of organisms at thiobiotic stations were comparable to total abundances at oxybiotic stations. Highest thiobiotic abundance was 202 051 organisms per m2; highest oxybiotic abundance was 240 572 organisms per m2. The thiobios is dominated by representatives of the lower Bilateria (viz. Gnathostomulida, Platyhelminthes and Aschelminthes). These groups accounted for 50–80% of all the organisms present in the thiobiotic stations but less than 20% of all organisms in the oxybiotic stations. At two thiobiotic stations, over 50% of all organisms were gnathostomulids. Thiobios included macrofaunal as well as meiofaunal components. Peak abundances of amphipods were associated with the thiobiotic environment.
Point mutations during generation of expression-linked extra copy of trypanosome surface glycoprotein gene

Trypanosomes exhibit antigenic variation by the sequential expression of a series of antigenically distinct variable surface glycoproteins (VSGs). On the basis of cDNA sequencing and/or terminal amino acid analyses of 10 Trypanosoma brucei VSGs1–6, the approximately 500 amino acids of a nascent VSG can be divided into (N-terminus to C-terminus) a hydrophobic signal peptide (∼20 amino acids), a variable region (∼360 amino acids), a homology region (∼100 amino acids) which can be used to classify the VSGs into one of two homology subsets and a hydrophobic tail (∼20 amino acids) that is not present in the mature VSG4,5. Expression of some VSGs is accompanied by the production of an expression-linked extra copy (ELC) of a basic copy (BC) VSG gene7–9. We have now compared the sequence of a cDNA representing an ELC gene with its corresponding BC gene sequence. We find that the codons specifying the variable region contain nucleotide changes at 4% of the positions, while those specifying the homology region of the VSG are identical and the 17 codons specifying the C-terminal hydrophobic tail contain 11 nucleotide changes. The 3′-nontranslated region between the termination codon and the poly(A) (in the cDNA) is quite different in the two sequences. As the trypanosome serodeme contains only one BC gene coding for this VSG, point mutations seem to be actively introduced into specific areas of the coding sequence during the generation of the ELC gene. These point changes potentially increase the repertoire of immunologically distinct VSGs available to the trypanosome, similar to the way in which somatic mutations contribute to the diversity of the variable regions of immunoglobulins10. An alternative interpretation that cannot be completely eliminated is that a second BC gene is lost during the generation of the ELC.
Facile air oxidation of the conjugate base of rofecoxib (Vioxx™), a possible contributor to chronic human toxicity

Abstract The COX-2 inhibitor rofecoxib (Vioxx ™ , 1 ) ionizes under physiological conditions to an anion that reacts readily with dioxygen to form inter alia the reactive maleic anhydride derivative 6 , a potentially toxic compound.
Quantifying the competitive impact of a new entrant

Abstract Quantifying the impact on sales and profits of existing firms due to a competitive entry is an important practical problem from both a managerial and a policy perspective. In this article we apply the well-known gravitational model to measure the sale impact of the planned entry of a new shopping center. The use of the model in this context is illustrated through two actual applications. Data were collected from a telephone survey of a random sample of local households. Respondents were asked a variety of questions about their shopping behavior, including their eatings of the arreactiveness of the new and existing malls. In addition, we collected the usual data on mall size, travel time, population size, etc. The gravity model was formulated as a logit model and estimated by the well-known maximum likelihood procedure. It was found that mall choice could be explained by a simple model that used the following three variables: mall size, travel time, and the attractiveness of the mall. The estimated model was then used to quantify the competitive impaxct of a new shopping center under alternative scenatios. The article concludes with some recommendations on the practical use of such models.
Virtual Rivers: Lessons From the Mountain Rivers of the Colorado Front Range

A rich tradition in historical environmental change emerged in the 20th century within the discipline of fluvial geomorphology the study of river land forms. This tradition has produced considerable fruit, including a scientific and historic understanding of river channel change that has reached a much broader audience, including planners, environmentalists, teachers, engineers, and historians. While historical information is usually qualitative in nature, and therefore not easily incorporated into empirical equations or computer models, the historical perspective is of utmost importance to understanding river systems and predicting their future behavior. Virtual Rivers: Lessons from the Mountain Rivers of the Colorado Front Range is a highly successful application of the historical tradition to the Colorado Front region.
THE MISSING DATA ASSUMPTIONS OF THE NONEQUIVALENT GROUPS WITH ANCHOR TEST (NEAT) DESIGN AND THEIR IMPLICATIONS FOR TEST EQUATING

The nonequivalent groups with anchor test (NEAT) design involves missing data that are missing by design. Three popular equating methods that can be used with a NEAT design are the poststratification equating method, the chain equipercentile equating method, and the item-response-theory observed-score-equating method. These three methods each make different assumptions about the missing data in the NEAT design. Though studies have compared the equating performance of the three methods under the NEAT design, none has examined the missing data assumptions and their implications for such comparisons. The missing data assumptions can affect equating studies because it is necessary to fill in the missing data or their distribution in some way in order to have a true, or criterion, equating function to compare the accuracy and bias of the different methods. If the missing data or their distribution are filled in using missing data assumptions that correspond to a given method, that may favor that method in any comparison with the others. This paper first describes the missing data assumptions of the three equating methods and then performs a fair comparison of the 3 methods using data from 3 different operational tests. For each data set, we examine how the 3 equating methods perform when the missing data satisfy the assumptions made by only 1 of these equating methods. The chain equating method is somewhat more satisfactory overall than the other methods in our fair comparison of the methods; hence, we recommend that equating practitioners seriously consider the chain equating method when using the NEAT design. In addition, we conclude that the results from the different equating methods will tend to agree with each other when proper equating conditions are in place. Moreover, to uncover problems that might not reveal themselves otherwise, it is important for operational testing programs to apply multiple equating methods and study the differences among their results.
The effect of single dose, intravenous cyclophosphamide on the mouse intestinal IgA response to cholera toxin

Abstract The IgA response of gut associated lymphoid tissue (GALT) to enteric pathogens is a vital component of the mucosal barrier. This study describes the effect of cyclophosphamide (Cy) on the IgA anti-CT response of Peyer's patch (PP) and lamina propria cells derived from mice previously challenged enterically with two weekly doses of 10 μg CT. Under normal circumstances, both PP and lamina propria responses peaked 7 days after the second dose of CT. To evaluate the effect of a single dose of Cy on this response, mice were given Cy (50 mg/kg) intravenously on days −2, 0, 2 or 7 relative to the initial dose of CT. Cultures of PP and jejunal segments were established 7 days after the booster dose of CT (time of normal peak response). A single dose of Cy suppressed the IgA anti-CT response of PP and, to a lesser extent, jejunal segment cultures only if the drug was given 2 days before the primary dose of CT. This suppression of the anti-CT response was overcome when Cy was given 2 days before CT priming, and CT was administered three times, on days 0, 7 and 14; thus, the effect of Cy was brief and did not appear to promote tolerance to CT. These data show that a single, moderate dose of Cy, given before enteric priming of the GALT, can inhibit the mucosal IgA response to CT. The effect of Cy is relatively brief and dependent upon the time at which the drug is given relative to the induction of the mucosal immune response.
Steroid receptors and steroid response in cultured LI 210 murine leukemia cells

Abstract MurineL1210 leukemia cells were cultured in the presence of various steroid hormones to determine their growth response. Cells maintained in medium containing glucocorticoids such as dexamethasone exhibit a 10–20% inhibition of growth, whereas progesterone or 17β-estradiol produce a 40–50% inhibition of growth. The response is due to growth inhibition and not to any cytolytic effect of the steroids. L1210 cytoplasmic and nuclear extracts contain high affinity binding sites for [3H]dexamethasone, [3H]progesterone and [3H]17β-estradiol. Competition with various steroids indicate that estrogens bind to one class of cytoplasmic binding sites, while glucocorticoids and progestins bind to a second class of receptor sites. These receptors appear not to be completely responsible for growth inhibition since there is no correlation between the magnitude of growth inhibition and the intracellular concentration of receptor sites and since the concentration of steroid required to cause significant growth inhibition exceeds those concentrations required to saturate the cytoplasmic receptors.
Single-incision technique for internal jugular vein tunneled vascular access in the pediatric population

Purpose To describe the technical success and outcomes of a single incision technique for placement of internal jugular (IJV) tunneled vascular access devices in children. Materials and Methods A retrospective 4 year review was performed of 15 children (8 males, 7 females) who underwent placement of single incision IJV tunneled vascular access catheters. The single incision technique was defined as utilizing one incision with an ultrasound guided long needle tunneled venipuncture to create both the subcutaneous tunnel and the venous access. Radiologic and medical records were reviewed for technical success, early and delayed mechanical and infectious complications. The mean age of the children was 11.0 yrs (range 1.0 - 18.7) and the mean weight was 44.2 kg (range 9.6 - 99.0). Indications for the vascular access as per SIR criteria included; TPN and medications (8), antibiotic therapy (5), chemotherapy (2), immunotherapy (1), and dialysis (1). Results 17 primary insertions were performed in 15 patients. Technical success was 100%. Catheter types included non cuffed central line (14), cuffed hemodialysis catheter (1), cuffed central line (1), and a port (1). One catheter was placed in 14 patients and 3 catheters in 1 patient. There were no procedure related complications. The mean fluoroscopy time was 5.3 mins (0.7-14.7). The total catheter days for initial insertions was 1265 catheter days (mean 74.4 days, range 3 - 502 days). Mechanical and infectious complications occurred at a rate of 0.29 and 0.14 per 100 total catheter days respectively. The rate of removal for mechanical and infectious complications was 0 and 0.07 per 100 total catheter days respectively. Non-IR salvages (tPa) (75% of salvages), and IR salvages (25% of salvages) prolonged catheter days by an average of 28.5 days (range 10 - 81 days). Three catheters were still in use at the end of this study. Conclusion Radiologically guided single-incision technique is a safe and technically feasible method for insertion of central venous access devices in pediatric patients. Placing them in children has appeal when the conventional double-incision technique may be challenging, such as in those with a tracheostomy.
SOME ISSUES IN THE FOUNDATION OF STATISTICS

After sketching the conflict between objectivists and subjectivists on the foundations of statistics, this paper discusses an issue facing statisticians of both schools, namely, model validation. Statistical models originate in the study of games of chance, and have been successfully applied in the physical and life sciences. However, there are basic problems in applying the models to social phenomena; some of the difficulties will be pointed out. Hooke’s law will be contrasted with regression models for salary discrimination, the latter being a fairly typical application in the social sciences.
Thai and American fathers’ involvement with preschool‐age children

Father involvement in caregiving and the socialization of preschool‐age children were examined in 40 Thai and 24 American families using the PICCI. The PICCI showed reasonably good internal consistency among Thai families. Mothers in both societies were far more likely to be involved with children than fathers in the respective cultures. Among both Thai and American fathers, involvement in caregiving and decision‐making was not significantly related. American fathers were significantly more likely to be involved in childcare and the socialization of preschoolers than Thai fathers. Thai fathers were more likely to receive support from extended family members and institutional sources for involvement in childcare than American fathers. There were no significant relationships between support received and involvement with children for either group of fathers.
Stress compounds from Nicotiana rustica inoculated with TMV

Abstract Three new sesquiterpenoid stress compounds, occidenol, occidentalol and trans -occidentalol, have been isolated from the leaves of Nicotiana rustica inoculated with TMV.
DEMETER, a DNA Glycosylase Domain Protein, Is Required for Endosperm Gene Imprinting and Seed Viability in Arabidopsis

We isolated mutations in Arabidopsis to understand how the female gametophyte controls embryo and endosperm development. For the DEMETER (DME) gene, seed viability depends only on the maternal allele. DME encodes a large protein with DNA glycosylase and nuclear localization domains. DME is expressed primarily in the central cell of the female gametophyte, the progenitor of the endosperm. DME is required for maternal allele expression of the imprinted MEDEA (MEA) Polycomb gene in the central cell and endosperm. Ectopic DME expression in endosperm activates expression of the normally silenced paternal MEA allele. In leaf, ectopic DME expression induces MEA and nicks the MEA promoter. Thus, a DNA glycosylase activates maternal expression of an imprinted gene in the central cell.
Human Hemapoietic Cell Lines: A Progress Report

Alarge number of human cell lines have been established from leukocytes of the peripheral blood, lymph and lymph nodes, and bone marrow in various hematopoietic disorders. Nearly 500 such cell lines have been started in our laboratory and maintained or preserved in cell banks, and 50 or more similar cell lines have been started in other laboratories (Table 1). The purpose of this presentation is to provide a summary of the techniques used in culturing these interesting cells, and a description of their characteristics which provide unusual opportunities for biological and biochemical research.
Training research in aging on the fluid ability of inductive reasoning

Abstract The modifiability of older adults' performance on Induction tasks was examined through cognitive training. The posttraining performance of 52 older adults ( X age = 70.3 years ) was assessed with regard to a transfer-of-training paradigm and maintenance of training effects at three posttests (one week, one month, six months). A pattern of differential training transfer across the posttest battery of fluid and crystallized intelligence measures was predicted, with the largest training effects expected for near transfer (Induction) measures. The predicted pattern of training transfer was obtained at one-week and one-month posttests, with significant training effects to the nearest Induction measure. Large retest (practice) effects across posttests also occurred for training and control groups. This research contributes to the position that modifiability of intellectual performance through cognitive intervention extends across the adult life span.
Three Levels of Style in Augustine of Hippo and Gregory of Nazianzus

Abstract: In Book 4 of De doctrina Christiana St. Augustine suggests that the three levels of style in Christian oratory should reflect the level of emotional impact on the audience, which would result in frequent variation through the course of the speech. Augustine9s literary theory seems to be in complete agreement with contemporary oratorical practice, not only Latin, in the West, but Greek too— witness St. Gregory of Nazianzus, whose Oration 42, The Last Farewell , is used as an example in this article. Finally, a comparison between Augustine9s views and those of some later Greek rhetoricians suggests that he may have been influenced as much by their ideas as by his acknowledged source and predecessor, Cicero.
The interaction of domain knowledge and linguistic structure in natural language processing: interpreting hypernymic propositions in biomedical text

Interpretation of semantic propositions in free-text documents such as MEDLINE citations would provide valuable support for biomedical applications, and several approaches to semantic interpretation are being pursued in the biomedical informatics community. In this paper, we describe a methodology for interpreting linguistic structures that encode hypernymic propositions, in which a more specific concept is in a taxonomic relationship with a more general concept. In order to effectively process these constructions, we exploit underspecified syntactic analysis and structured domain knowledge from the Unified Medical Language System (UMLS). After introducing the syntactic processing on which our system depends, we focus on the UMLS knowledge that supports interpretation of hypernymic propositions. We first use semantic groups from the Semantic Network to ensure that the two concepts involved are compatible; hierarchical information in the Metathesaurus then determines which concept is more general and which more specific. A preliminary evaluation of a sample based on the semantic group Chemicals and Drugs provides 83% precision. An error analysis was conducted and potential solutions to the problems encountered are presented. The research discussed here serves as a paradigm for investigating the interaction between domain knowledge and linguistic structure in natural language processing, and could also make a contribution to research on automatic processing of discourse structure. Additional implications of the system we present include its integration in advanced semantic interpretation processors for biomedical text and its use for information extraction in specific domains. The approach has the potential to support a range of applications, including information retrieval and ontology engineering.
Sodium Chloride Requirement of Bobwhite Quail Chicks

Abstract Six experiments were conducted to determine the optimum dietary sodium chloride (NaCl) level for Bobwhite quail from hatch to 5 weeks of age. Levels of .15% supplemental NaCl (.09% total Na, .15% total CI) or less were inadequate to support maximum growth and livability. Levels of .20% supplemental NaCl (.109% total Na, .18% total CI) or more supported maximum growth and livability. Feed consumption decreased as NaCl levels decreased, while grams feed per gram body weight increased.
Synthesis of Substituted Catechols using Nitroarene Dioxygenases

Abstract The nitroarene dioxygenases are in the class of Rieske iron-containing oxygenases that incorporate atmospheric oxygen into substrates via electrophilic attack on the substrate. In their native role, the nitroarene dioxygenases start degradative pathways by hydroxylating nitro-substituted, and adjacent unsubstituted carbons of nitroaromatic compounds. The reaction yields the corresponding nitro-cis-cyclohexadienediol, which is unstable and spontaneously re-aromatizes to form a catechol and nitrite. In bacterial metabolism, the specificity of the hydroxylation determines subsequent steps in degradation pathways. Experiments were done to find whether the specificity could be exploited to direct the hydroxylation of multiply substituted aromatic substrates and thereby produce novel catechols. Recombinant strains carrying genes for nitroarene dioxygenases were used for transformation of various substituted nitroaromatic compounds. The reactions were analyzed using HPLC to track substrate consumption and product formation, then GC–MS and NMR to identify the reaction products. A number of substituted catechols were obtained using the recombinant biocatalysts. The nitro-substituted carbon was the primary site for dioxygenase hydroxylation. When substrates included nitro and halogen substituents, the halogen-substituted positions were also targeted, but less frequently than the nitro-substituted site. The production of catechols was limited in batch fermentations, likely due to toxicity of the quinones that result from air oxidation of catechols. The nitroarene dioxygenases will serve as catalysts for direct synthesis of highly substituted catechols, however, the reaction conditions must be engineered to overcome product toxicity and allow sustained accumulation of catecholic products.
Urbanization in developing countries: Current trends, future projections, and key challenges for sustainability

The purpose of this paper is to provide a broad overview of the recent patterns and trends of urban growth in developing countries. Over the last 20 years many urban areas have experienced dramatic growth, as a result of rapid population growth and as the world’s economy has been transformed by a combination of rapid technological and political change. Around 3 billion people—virtually half of the world’s total population-now live in urban settlements. And while cities command an increasingly dominant role in the global economy as centers of both production and consumption, rapid urban growth throughout the developing world is seriously outstripping the capacity of most cities to provide adequate services for their citizens. Over the next 30 years, virtually all of the world’s population growth is expected to be concentrated in urban areas in the developing world. While much of the current sustainable cities debate focuses on the formidable problems for the world’s largest urban agglomerations, the majority of all urban dwellers continue to reside in far smaller urban settlements. Many international agencies have yet to adequately recognize either the anticipated rapid growth of small and medium cities or the deteriorating living conditions of the urban poor. The challenges of achieving sustainable urban development will be particularly formidable in Africa. q 2005 Elsevier Ltd. All rights reserved.
Doctoral Students in Special Education: Characteristics and Career Aspirations

This study was part of a comprehensive investigation on the supply and demand of special education faculty (see also Sindelar & Rosenberg; Pion, Smith & Tyler; and Smith, Pion, Tyler, & Gilmore, this issue). Students enrolled in doctoral programs during the Spring of 1999 were surveyed about their doctoral programs, educational background, experiences in applying to doctoral programs in special edu- cation, current doctoral study, post-graduation plans, and background information. The survey had an 82% response rate (1,267 students). The study found that doctoral students were older and their primary consideration in selecting a doctoral program was not having to relocate. Overall, students were fairly satisfied with the training they received in research skills, less so in areas of college teaching, administration/ supervision, and cultural and linguistic diversity. Additionally, less than half (44%) were interested in faculty positions after graduation.