cssi/SciSciGPT-SciSciNet huggingface dataset:
Developing a plan for solving a problem: A representational shift

Abstract Research analyzing transitions from lower to higher levels of problem solving has focused either on quantitative increments in processing demands (Case, 1984; Klahr & Robinson, 1981) or on qualitative shifts in the organization of representations (Fischer & Pipp, 1984; Piaget, 1976). This study is concerned with distinguishing the value of these two approaches to problem solving through a microgenetic analysis of children's initial attempts to solve the Tower of Hanoi problem. As suggested by Siegler and Crowley (1991), a microgenetic approach is particularly useful in determining the process of cognitive change. One-hundred and thirty-six children, ages 6 through 8 years, were presented with the standard three-disc problem and allowed 3 minutes to complete it. The quality of the children's performance was analyzed by noting the positioning of the first move, the number and location of illegal moves, and the frequency and location of optimal moves. The results indicate that qualitative shifts in children's representation of the problem space are a crucial aspect of successful performance.
Pro-homology and isomorphisms of pro-groups

Abstract We extend the scope of some useful theorems of E. Dror and J. Stallings of which the following result of Stallings is easy to state: A homomorphism θ: A→B of nilpotent groups is an isomorphism if and only if θ induces an isomorphism and an epimorphism on the first and the second homology groups with integer coefficients, respectively . We extend and enlarge the algebraic framework to the category of pro-groups in a natural way so that an anaogue of these results of Dror and Stallings can be appropriately stated and proved. This is done in a natural manner so that our extended results can be useful in pro-homotopy theory or shape theory which is analogous to the usefulness of the results of Dror and Stallings in the context of homotopy theory. As an application, we obtain a version of a Whitehead Theorem in pro-homotopy and shape theory which only involves homology pro-groups; a complete proof of this result will be given elsewhere.
Scaling up the MIT holographic video system

Electronic holographic imaging, developed at the MIT Media Laboratory Spatial Imaging Group over the past five years, is a truly three-dimensional real-time digital imaging medium. Recent work in holographic video has demonstrated that the crucial technologies -- computation, electronic signal manipulation, and optical modulation and scanning -- may be scaled up to produce larger, more interactive, full-color holographic images. Synthetic images and images derived from real-world scenes are quickly converted into holographic fringe patterns using newly-developed `diffraction-specific' computational algorithms. A parallel- architecture signal processing system distributes the holographic video among multiple output boards. To diffract light so as to form an image in real time, the display employs an 18- parallel-channel, scanned, time-multiplexed acousto-optical modulator. The successful scaling- up of the MIT holographic video system has depended on the application of the concepts of electronic and optical parallelism at every stage.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Isolation of two distinct populations of cells from fat kidney cortex and their use in the study of chemical-induced toxicity

Procedures for the isolation and enrichment of cell populations from suspensions of rat kidney cortical cells were developed. Using Percoll density-gradient centrifugation, two populations of cells were obtained; marker enzymes [alkaline phosphatase and gamma-glutamyltransferase for proximal tubular (PT) cells and hexokinase for distal tubular (DT) cells] and functional responses (stimulation of PT cell oxygen consumption by succinate and inhibition of DT cell oxygen consumption by amiloride) were then employed to identify and assess the purity of the two fractions. The PT cell fraction was estimated to contain 97% PT cells and the DT cell fraction was estimated to contain 88% DT cells. Staining with toluidine blue and light microscopy showed that PT cells contained a brush border, were larger than DT cells, and had more intensely staining nuclei than DT cells. To demonstrate the usefulness of these cell preparations in the study of biochemical mechanisms of renal cell injury, time- and concentration-dependent effects of the PT cell-specific nephrotoxin cephaloridine (CPH) on PT and DT cell trypan blue exclusion were examined. CPH was toxic in PT cells but not in DT cells; viability of PT cells incubated with 0.1 or 1 mM CPH for 2 h was 57 or 34%, respectively, compared to 81% for control cells; viability of DT cells incubated with 0.1 or 1 mM CPH for 2 h was 74 or 71%, respectively, compared to 74% for control cells. This method thus provides highly enriched preparations of freshly isolated PT and DT cells that retain their unique properties and are suitable for studies of biochemical mechanisms of chemical toxicity and nephron heterogeneity.
Cell Surface AMPA Receptors in the Rat Nucleus Accumbens Increase during Cocaine Withdrawal But Internalize after Cocaine Challenge in Association with Altered Activation of Mitogen-Activated Protein Kinases

Although some studies report increased responsiveness of nucleus accumbens (NAc) AMPA receptors (AMPARs) after withdrawal from repeated cocaine treatment, others report decreased responsiveness after withdrawal plus cocaine challenge. Here we examine this apparent contradiction by quantifying cell surface and intracellular AMPAR subunits in the NAc before and after a challenge injection in behaviorally sensitized rats. Because MAPKs (mitogen-activated protein kinases) regulate AMPAR trafficking and are implicated in addiction, we also evaluated phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38. Glutamate receptor 1 (GluR1) and GluR2 surface/intracellular (S/I) ratios were increased after 14 d of withdrawal in sensitized rats but were decreased 24 h after challenge with cocaine (which elicited a sensitized locomotor response) or saline (which elicited conditioned locomotion). These findings suggested redistribution of GluR1/2-containing receptors, a possibility supported by immunoprecipitation experiments indicating that most AMPARs in the NAc are GluR1/2 or GluR2/3, with few homomeric GluR1 or GluR1/3 receptors. In sensitized rats, ERK phosphorylation in the NAc increased during withdrawal and normalized after cocaine challenge. JNK phosphorylation also increased after withdrawal, but after cocaine challenge, it was inversely related to GluR1 and GluR2 S/I ratios. After saline challenge, p38 phosphorylation was increased. In summary, surface expression of GluR1/2-containing AMPARs increased in the NAc of sensitized rats, but AMPARs internalized after a single reexposure to cocaine or cocaine-related cues. ERK phosphorylation paralleled AMPAR surface expression. Although JNK results were complex, JNK and p38 may be involved in AMPAR internalization after cocaine or saline challenge, respectively.
Role of φ29 connector channel loops in late-stage DNA packaging.

Abstract Double-stranded DNA bacteriophages and their eukaryotic virus counterparts have 12-fold head–tail connector assemblages embedded at a unique capsid vertex. This vertex is the site of assembly of the DNA packaging motor, and the connector has a central channel through which viral DNA passes during genome packaging and subsequent host infection. Crystal structures of connectors from different phages reveal either disordered residues or structured loops that project into the connector channel. Given the proximity to the translocating DNA substrate, these loops have been proposed to play a role in DNA packaging. Previous models have proposed structural motions in either the packaging ATPase or the connector channel loops as the driving force that translocates the DNA into the prohead. Here, we mutate the channel loops of the Bacillus subtilis bacteriophage φ29 connector and show that these loops have no active role in translocation of DNA. Instead, they appear to have an essential function near the end of packaging, acting to retain the packaged DNA in the head in preparation for motor detachment and subsequent tail assembly and virion completion.
Ingenious gene generation.

Abstract Anaplasma marginale is a tick-borne rickettsia that causes persistent infections in its mammalian host. This is achieved by expression of numerous diverse variants of outer membrane proteins. New data show how the rickettsia makes most efficient use of its small genome to achieve this diversity. We discuss the implications for anaplasmosis and for other rickettsial diseases.
Intramolecular C-H activation by inferred terminal cobalt imido intermediates.

Reaction of TpR,MeCo(I) dinitrogen complexes (R = iPr, tBu) with trimethylsilyl azide yields structurally characterized compounds that imply the formation of reactive intermediates of the type TpR,MeCoNSiMe3. These cobalt imido species apparently abstract hydrogen from the 3-substituent of the Tp-ligand, leading to the formation of amido complexes accompanied by either Co−C bond formation (R = tBu) or C−C bond formation (R = iPr).
Application of the sanderson polar covalence model to energetics of CO adsorption

Abstract The model of polar covalence developed by R.T. Sanderson was used to calculate energies of chemisorption of CO g on metal surfaces. Internal energies of adsorption were calculated for four stereochemical possibilities including linear, two site bridge bonded, and dissociated CO on fourteen first, second, and third row transition metals. The influence of surface steps, other defects, and CO-CO interactions were not calculated, although the influence of steps on certain metals is discussed. The effect of metal site coordination number was also calculated. Higher coordination numbers, are generally associated with longer bond lengths and smaller heats of adsorption. Very good agreement, less than 3 kcal mol −1 difference between experiment and calculation, was observed for molecularly adsorbed CO. The enthalpy and Gibbs energy of dissociative adsorption at 298 K were calculated for seventeen transition metals and Si. CO dissociation is thermodynamically allowed on Mn, Cr, Fe, Ni, Re, W and Si at both 10 −10 Torr and 1 atm CO. Dissociation is forbidden on Ru, Rh, Ir, Ag, Pd, Au, and Pt at both pressures. Dissociation is forbidden at 10 −10 Torr, but allowed at 1 atm CO on Co, Cu, Mo, and Os.
Social structure and global climate change : Sociological propositions concerning the greenhouse effect

Abstract Although there is accumulating evidence that socioeconomic and political organization are central driving forces behind greenhouse gas emissions and deforestation, most recent discussions of global environmental degradation have neglected the role of social structure in climate change. We critically assess neo-Malthusianism and macrosocial theories of development to identify a set of hypotheses about the social structural sources of the greenhouse effect and their role in constraining possible mitigation strategies. Although neo-Malthusian arguments about population growth, affluence and advanced technology may prove decisive in the long run, arguments derived from modernization, ecological-evolutionary, world-system and state-centered theories of development point to a set of emergent properties, non-linearities and equity conflicts that may significantly alter these projections. Future policy discussions need to be informed by these considerations of social structure to be effective.
Critical differences in the serial measurement of three biochemical markers of bone turnover in the sera of pre- and postmenopausal women.

Abstract Objectives: The purpose of this investigation was to quantify the biologic, day-to-day variability and critical differences in serum levels of crosslinked collagen N-telopeptides (NTx), procollagen aminoterminal extension propeptides (PINP) and bone specific alkaline phosphatase (bAP) in healthy women. Design and methods: Seven blood samples were collected from12 pre- and 15 postmenopausal women over 4 to 6 months. NTx, PINP and bAP levels were determined utilizing enzyme- and radioimmunoassay techniques. Results: The within-subject coefficient of variation (C.V.) in serum bAP, NTx and PINP levels was 7.1, 10.6 and 12.4% respectively. These variances did not differ significantly among premenopausal women when compared with postmenopausal subjects. Combining terms for analytical and biologic variability revealed that a critical difference between 2 successive serial measurements is 24% for bAP, 34% for NTx and 38% for PINP. Conclusion: Circulating levels of NTx, PINP and bAP are stable over time periods of several months, allowing for the determination of significant changes in skeletal metabolism of women.
A framework for the evaluation of geomulticast delivery accuracy in mobile ad-hoc networks

Geomulticast is a specialized location-dependent multicasting technique, where messages are multicast to specific user groups within a specific zone. We first present an overall architecture that can be used to support the delivery of geomulticast services in the challenging environment of mobile ad hoc networks, by identifying several geomulticast zone formulation and representation methods and defining the network structure and various components. As part of this architecture, we utilize a mobility based clustering (MBC) method in order to cluster the various mobile nodes dynamically and adaptively into groups. We also present and investigate two geomulticast membership management strategies which depend on the geolocation storage position. Based on this architecture, we formulate and develop an analytical framework and model that is used to evaluate the performance of different design alternatives and protocols. We also obtain some insight about the impact of the various design and operational parameters on the overall system performance. Since one of our main objectives is to design architectures that support geomulticast services with high delivery accuracy, we introduce, define and analyze parameters such as the probability of geomulticasting error and the accuracy of geomulticast packet delivery.
The impact of process control technology on Turkish chemical industry

Abstract This paper analyzes the impact of process control technology on production performance and economies of scale in the Turkish chemical industry. In theory, the application of new technologies leads to significant improvements in production performance, and this effect is also observed in our case study firms. However, while the impact of new technologies on economies of scale would, theoretically, be a decline in economies of scale, our case study shows that economies of scale for both plants and firms have increased in the chemical industry.
Seismic response of critical interdependent networks

During the last decade, critical infrastructure systems such as electric power, water distribution, transportation and telecommunications have been stressed by significant natural hazards and human errors leading to malfunction. Earthquakes, blackouts and satellite failures have evidenced the vulnerability of these growing networked systems threatening the continuity of the United States' economy. The potential for malicious perturbations to these systems is also an important current concern. However, the underlying susceptibility of these networks to disruptive events is in large part due to the increasingly complex pattern of interdependencies that tie these civil infrastructures together. This paper mainly investigates the effect of seismic disruptions on the performance of real interdependent networks. Maintenance-induced malfunctions and coordinated attacks are also studied for completeness. Several degrees of interconnectedness are explored. Interdependent network fragility curves are introduced to display the effect of these different strengths of coupling. Characterization of the performance displayed by the networks is utilized to propose mitigation actions and study propagation of their effects. It is shown that minimal strategic interventions propagated through the network can generate a more resilient interdependent entity. Copyright © 2006 John Wiley & Sons, Ltd.
Presence and Correlation of Fine Structure in Jovian Decametric Radiation

JUPITER'S non-thermal emission in the decameter region of the spectrum takes the form of sporadic radio noise storms having durations ranging from minutes to several hours1. Observers agree that the storms show fine structure, in part composed of bursts which typically have durations ranging from several tenths of a second to several seconds. However, there has not been agreement as to the presence of still finer structure or the intrinsic origin of any of the fine structure.
Changes for merit goods: third world family planning.

This article examines the arguments for and against user fees privatisation and decentralisation of health care and family planning delivery systems and compares the effectiveness of fee-for-service delivery by decentralised systems with that of centralised systems with services provided free of charge. Developing countries have achieved remarkable reductions in fertility rates in the past 25 years but continuing gains depend largely upon increasing the capacity of family planning and health care delivery systems in rural areas. (EXCERPT)
MICROCOSM EXPERIMENTS HAVE LIMITED RELEVANCE FOR COMMUNITY AND ECOSYSTEM ECOLOGY: REPLY

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CONSTRAINTS OF AXIONS FROM WHITE DWARF COOLING

In this paper, we perform numerical calculations on the white dwarf cooling process. We found that it provides a constraint on the axion mass. The upper bound is 0.01 eV.
Power supply for resistance welding: A co-operative approach

Co-operation among the electrical utility, the welding equipment manufacturer, and the industrial user is the prime condition for a satisfactory solution to the power supply problem in the resistance welding field. A discussion of one method of approach to the problem is presented as a contribution to the promotion of mutual understanding among the parties concerned.
HIV-1 Vpu Antagonism of Tetherin Inhibits Antibody-Dependent Cellular Cytotoxic Responses by Natural Killer Cells

ABSTRACT The type I interferon-inducible factor tetherin retains virus particles on the surfaces of cells infected with vpu -deficient human immunodeficiency virus type 1 (HIV-1). While this mechanism inhibits cell-free viral spread, the immunological implications of tethered virus have not been investigated. We found that surface tetherin expression increased the antibody opsonization of vpu -deficient HIV-infected cells. The absence of Vpu also stimulated NK cell-activating FcγRIIIa signaling and enhanced NK cell degranulation and NK cell-mediated antibody-dependent cellular cytotoxicity (ADCC). The deletion of vpu in HIV-1-infected primary CD4 + T cells enhanced the levels of antibody binding and Fc receptor signaling mediated by HIV-positive-patient-derived antibodies. The magnitudes of antibody binding and Fc signaling were both highly correlated to the levels of tetherin on the surfaces of infected primary CD4 T cells. The affinity of antibody binding to FcγRIIIa was also found to be critical in mediating efficient Fc activation. These studies implicate Vpu antagonism of tetherin as an ADCC evasion mechanism that prevents antibody-mediated clearance of virally infected cells. IMPORTANCE The ability of the HIV-1 accessory factor to antagonize tetherin has been considered to primarily function by limiting the spread of virus by preventing the release of cell-free virus. This study supports the hypothesis that a major function of Vpu is to decrease the recognition of infected cells by anti-HIV antibodies at the cell surface, thereby reducing recognition by antibody-dependent clearance by natural killer cells.
Polyps in continent catheterizable bladder channels.

Abstract Objective We describe our experience with polyps encountered in bladder continent catheterizable channels. Material and methods An IRB-approved retrospective study was conducted on all patients at Children's Hospital of Wisconsin with continent catheterizable channels managed by a single physician over a 16-year time period. Results Fifty-five patients were identified with bladder channels. During a median follow-up of 7 years (range 3–16 years), 20% (11/55) of bladder channels developed polyps. The time to diagnosis of a polyp in bladder channels from initial surgery ranged from 3 months to 8 years (median of 29 months). Fifty-five percent (6/11) of patients who developed bladder polyps were symptomatic. All patients' symptoms resolved after treatment by endoscopic resection. Forty-five percent (5/11) of polyps recurred after resection. The time of recurrence ranged from 4 months to 7 years (median of 19 months). Polyps were universally benign inflammatory granulomatous tissue. Conclusion This is the first series reporting the incidence of polyps in bladder catheterizable channels. Patients with continent catheterizable bladder channels can develop symptomatic polyps in their channels, of unknown long-term significance and risk.
Using decision trees to select the grammatical relation of a noun phrase

We present a machine-learning approach to modeling the distribution of noun phrases (NPs) within clauses with respect to a fine-grained taxonomy of grammatical relations. We demonstrate that a cluster of superficial linguistic features can function as a proxy for more abstract discourse features that are not observable using state-of-the-art natural language processing. The models constructed for actual texts can be used to select among alternative linguistic expressions of the same propositional content when generating discourse.
Optimal reallocation of R&D money under budget decrement

There sometimes arises in R&D (and other) management the necessity to revise the current allocation of R&D money among projects because of a decrement in the total budget appropriated for research. What is usually required in such circumstances is a quick computational procedure (though not necessarily 100 percent accurate) based on a minimum of input data. New constraints expressing minimum funding to be given to each project so as to maintain stability in personnel or satisfy prior commitments must also be taken into consideration. A simple algorithm is developed on the assumption that the current allocation is optimal at the original budget level. Using the Kuhn-Tucker theory in nonlinear programming, it is shown that this algorithm reaches the revised optimal solution in a finite number of iterations.
Soft X-Ray Amplification at 26.2 nm with 1-Hz Repetition Rate in a Table-Top System

Using a very small Nd/YAG pumping laser (0.45 J in 8 nsec), we have demonstrated high gain $(G\ensuremath{\approx}14--19\mathrm{cm}{}^{\ensuremath{-}1})$ and gain-length product $(\mathrm{GL}\ensuremath{\ge}5)$ in hydrogenlike B V ions at a wavelength of 26.2 nm (the 3-2 transition) at a repetition rate of 1 Hz. The preplasma in a ${\mathrm{B}}_{2}{\mathrm{O}}_{3}$ microcapillary was created from wall ablation with a 0.2-J (in 20 nsec) KrF laser. The gain was generated in the microcapillary plasma in a traveling wave regime by longitudinal pumping. This very efficient soft x-ray lasing system takes up less space than is available on a $4\mathrm{ft}\ifmmode\times\else\texttimes\fi{}10\mathrm{ft}$ optical table.
A model for the viscoelastic behavior of nanofilled hydrogel composites under oscillatory shear loading

A molecular model is proposed to predict the viscoelastic response of the hydrogels reinforced with nonpercolated nanoparticles with emphasis on the role of polymer–particle energetic interactions. The structure of the polymer layer adsorbed on the surface of the particles is analyzed using a scaling theory for reversible polymer adsorption. The energetic affinity between the monomers and filler surface is assumed to be weak and short range. Because of thermal fluctuations or the applied deformation, the transient junctions between the polymer segments and filler particles break after a finite period of time. The dynamics of the polymer segments is studied by a Maxwell type kinetic model. The resultsshow that monomer–filler energetic affinity can strongly affect the overall viscoelastic response of the hydrogel nanocomposite, even within the range of weak coupling between the monomers and filler surface. The model can also predict the strain amplitude dependence of the storage shear modulus based on the kinetics of adsoption/desorption of the interfacial monomers. The model predictions are compared with the experimental results for poly(L-lactide-co-ethylene oxide-co-fumarate) hydrogels reinforced with hydroxyapatite nanoparticles. The filled hydogel/apatite nanocomposites are useful as a model matrix to mimic the soft elastic and hard mineral phases of the bone matrix and as scaffolds for hard tissue regeneration. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
Q-switched operation of a coupled-resonator vertical-cavity laser diode

We report Q-switched operation from an electrically injected monolithic coupled-resonator structure which consists of an active cavity with InGaAs quantum wells optically coupled to a passive cavity. The passive cavity contains a bulk GaAs region which is reverse biased to provide variable absorption at the lasing wavelength of 990 nm. Cavity coupling is utilized to effect large changes in output intensity with only very small changes in passive cavity absorption. The device is shown to produce pulses as short as 150 ps at repetition rates as high as 4 GHz. A rate equation approach is used to model the Q-switched operation yielding good agreement between the experimental and theoretical pulse shape. Small-signal frequency response measurements also show a transition from a slower (∼300 MHz) forward-biased modulation regime to a faster (∼2 GHz) modulation regime under reverse-bias operation.
Behavioral and neurobiological markers of Alzheimer's disease in Ts65Dn mice: Effects of estrogen

Individuals with Down's syndrome (DS) develop neuropathological features similar to Alzheimer's disease (AD) early in life, including dementia, accumulation of beta-amyloid, and irregular phosphorylation of tau proteins. Ts65Dn mice, an animal model of DS, provide a unique method to investigate the mechanisms related to AD-like symptoms in DS and possible therapeutic interventions. Ts65Dn mice undergo a decline in cholinergic phenotype and cognitive deterioration beginning at 6-8 months of age. In middle-aged female Ts65Dn mice, estrogen supplementation alleviated these cholinergic and cognitive impairments. The current study investigated AD-like markers and the effects of estrogen in male Ts65Dn mice. Estrogen treatment prior to behavioral testing did not improve cognitive deficits in 6-month-old male Ts65Dn mice, but decreased total and phosphorylated (pS199) tau in the entorhinal cortex compared to normosomic animals. Hippocampal beta-amyloid(1-42) levels were increased in Ts65Dn animals, regardless of estrogen treatment. These findings further support Ts65Dn mice as a model for specific AD-like symptoms, and demonstrate that estrogen treatment of this type does not improve the cognitive ability of male Ts65Dn mice.
A Three-Dimensional Computational Simulation of Some Sources of Measurement Artifact in Microvascular Pulsed Ultrasound Doppler Velocimetry

Recent applications of 20 MHz pulsed ultrasound Doppler velocimetry (PUDVM) in microsurgical research have necessarily employed piezoelectric crystals whose diameter is not negligible compared to the lumen size (1-2 mm) of many vessels of interest. A three-dimensional numerical model was developed to explore relationships between actual and detected flow field parameters, for (steady) Poiseuille flow, when appreciable velocity gradients exist within the PUDVM sample volume. Validation studies showed that highly accurate velocity profiles could be obtained in the limiting case of a very small sample volume (0.1 mm radius), but that for currently employed crystals (approximately equal to 0.5 mm radius) there was appreciable underestimation of the centersteam velocity, and appreciable overestimation of the flow stream diameter. Errors in perceived velocity and flow rate were found to be relatively insensitive to perturbations in the sample volume thickness, in the size of the sampling range increment, or in the angle of insonation beam divergence. By contrast, these apparent flow parameters were found to be very sensitive to perturbations of sample volume diameter or of the Doppler angle. Small variations in the degree of partial sample volume overlap of the flowstream periphery were shown to be capable of causing large fluctuations in apparent flow stream diameter.
Effect of yohimbine on brain monoamines: an in vivo study.

Following the administration of yohimbine, an α2-adrenoreceptor antagonist, the levels of norepinephrine (NE), dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5HIAA) increased significantly in the lateral ventricular fluid of rats. These increases were abolished when animals were pretreated with α-methyl-para-tyrosine or reserpine. Dopamine (DA) was not detected in ventricular fluid either before or after yohimbine administration. Yohimbine administration did, however, increase intracellular DA levels in the corpus striatum. These findings indicate that yohimbine promotes NE and DA release in the brain and suggest that it also modifies the activity of the serotonin system.
In vivo release of beta human chorionic gonadotropin by luteinizing hormone releasing hormone stimulation and its clinical application as a remission criterion in patients with gestational trophoblastic disease.

Abstract In vivo responses of trophoblasts to luteinizing hormone releasing hormone (LHRH) stimulation in 48 gestational trophoblastic disease patients were observed. Serum beta human chorionic gonadotropin (β-hCG) levels after LHRH injection were significantly increased in patients with hCG values between 5 and 20 mIU/ml (minimal resistance group) but not in patients whose hCG levels were less than 5 mIU/ml (possible remission group). The sensitivity, specificity and the predictive values of LHRH stimulation test were 75.0, 91.3 and 95.5% in the possible remission group and 87.5, 20.0 and 77.8% in the minimal resistance group.
Differential enzymatic accessibilities of the 5' and 3' splice sites of β-globin pre-messenger RNA in splicing competent HeLa cell nuclear extract

Abstract Inhibition of oligonucleotide-directed cleavage of pre-mRNA using exogenously added E. coli RNase H has been utilized as a probe for mRNA-protein interaction. We now show that such an RNase H-like activity is present in splicing competent Hela cell nuclear extract. Using this extract and in vitro transcribed β-globin pre-mRNA, we have demonstrated that synthetic oligonucleotides, complementary to the splice site sequences, direct preferential cleavage of the 5′ splice site. Thus, these experiments using complementary oligonucleotide-directed, endogenous RNase H-like cleavage of pre-mRNA, suggest a useful probe for studying the mRNA-protein complex in vitro .
An Improved and Practical Headspace Gas Chromatographic Method for Determination of Carboxyl Acids Content in Wood Fibers

This paper reports an improved headspace gas chromatography (HS-GC) technique for the determination of carboxyl group content in wood fibers. The method is based on phase reaction conversion HS-GC ...
H Lyman a transmittance of thin C and Si/C foils for keV particle detectors

Abstract Interests in the use of thin foils as light attenuators and signal generators for energetic particle instruments in space have led to the measurement of transmittance of thin C and Si/C foils at 1216 A, where the most intense and ubiquitous photons in the solar system reside. Our results indicate that 1) a transmittance of
RENEWAL OF CELLS WITHIN TASTE BUDS

Colchicine blocks mitotic division of the epithelial cells surrounding the taste bud of the rat tongue. Response to chemical stimulation decreases 50 per cent 3 hours after colchicine injection as measured by recording the electrical activity from the taste nerve bundle. Radioautography, using tritiated thymidine, shows that those epithelial cells surrounding the taste bud divide and that some of the daughter cells enter the taste bud and slowly move toward the center. The life span of the average cell is about 250 ± 50 hours, although some cells have a much shorter and others a much longer life span. These studies suggest that the cells within the taste bud, as well as the nerves, undergo considerable change with time. Corresponding changes in function are considered.
Begin the Beguine: Relational Theory and the Pluralistic Third

Different clinical theories valorize particular aspects of clinical understanding. The author describes the need for analysts to hold themselves accountable through thinking about the blind spots that result from prizing these particular lenses. He explores the concept of the pluralistic third, which aims to think about clinical work with the use of theory external to our own. In examining the very beginning phase of an unusual analysis, he tries to examine particular aspects of his work including survival as an object for the patient, analytic play, and enactment. Even among relational analysts there are profound differences in how we interpret and make use of countertransference, particularly our disjunctive subjectivity from that of our patient. These differences point to the value of asking particular questions regarding how to hold ourselves accountable within the analytic process.
Microfossil assemblages on Tuscaloosa Seamount and their constraints on the age of the Nuʻuanu landslide, north of Oahu, HI

Abstract The Nuʻuanu submarine landslide, north of the Island of Oahu, is the largest of many debris avalanches along the flanks of the Hawaiian Islands. Several attempts have been made to date the Nuʻuanu landslide and to assess its relationship to the shield-building stage of Koʻolau Volcano as an indication of hazards that might be anticipated during the evolution of oceanic volcanoes. Previous age determinations based on magnetostratigraphy and the temporal distribution of turbidites have yielded a range of possible ages. We describe a distinctive fine-grained silty mudstone representing mantling sediment on the largest landslide block within the debris field, Tuscaloosa Seamount. This mudstone contains foraminifera and nannofossil assemblages that yield a micropaleontological age and paleoenvironmental determination for the interval immediately following landslide emplacement. The microfossils constrain the mantling sediment to have been deposited between 2.5 and 3.3 Ma, in offshore, mid- to lower-bathyal (∼1500–3000 m) water depth, consistent with a position on the upper flanks of Tuscaloosa Seamount. These findings indicate that landsliding occurred prior to or near the end of shield building at Koʻolau Volcano (2.9 Ma), and may have precipitated dramatic changes in volcano growth and deformation behavior, as well as changes in basalt geochemistry.
A configurational approach to Enterprise Strategy Scope: An Upper Echelons Perspective

Enterprise Strategy Scope is the range of stakeholder satisfaction realized by a firm. Using the Upper Echelons Perspective, this study takes a configurational approach in examining the correlates of Enterprise Strategy Scope by considering the environmental and organizational context as well as top management team's characteristics and firm performance. Empirical support was found for the two hypothesized types of enterprise strategy configurations. In addition, we discovered a third type of configuration which has not yet been discussed in the literature. Overall, these empirical results suggest that enterprise strategy is influenced by several contextual variables operating on multiple levels of analysis.
Intravenous Losartan Inhibits the Increase in Plasma Luteinizing Hormone and Water Intake Produced by Intraventricular Angiotensin II

Abstract In the presence of sex hormones, intraventricular injection of angiotensin II in female rats increases luteinizing hormone (LH) secretion, and this response is blocked by intraventricular losartan. There is evidence that in doses of 3 mg/kg or more systemically administered losartan blocks brain as well as peripheral AT1 angiotensin II receptors. Therefore, we tested the effect of intravenous losartan, 1 and 10 mg/kg, on the LH response to intraventricular angiotensin II in ovariectomized rats treated with estrogen and progesterone. The larger dose of losartan abolished the LH response. It also produced a marked reduction in the drinking response to intraventricular angiotensin II. The data provide additional evidence that in larger doses, peripherally administered losartan can penetrate the brain, and support the hypothesis that in female rats, the brain renin-angiotensin system plays an excitatory role in the regulation of LH secretion.
Matroid intersection algorithms

LetM 1 = (E, 91),M 2 = (E, 92) be two matroids over the same set of elementsE, and with families of independent sets 91, 92. A setI ∈ 91 ∩ 92 is said to be anintersection of the matroidsM 1,M 2. An important problem of combinatorial optimization is that of finding an optimal intersection ofM 1,M 2. In this paper three matroid intersection algorithms are presented. One algorithm computes an intersection containing a maximum number of elements. The other two algorithms compute intersections which are of maximum total weight, for a given weighting of the elements inE. One of these algorithms is “primal-dual”, being based on duality considerations of linear programming, and the other is “primal”. All three algorithms are based on the computation of an “augmenting sequence” of elements, a generalization of the notion of an augmenting path from network flow theory and matching theory. The running time of each algorithm is polynomial inm, the number of elements inE, and in the running times of subroutines for independence testing inM 1,M 2. The algorithms provide constructive proofs of various important theorems of matroid theory, such as the Matroid Intersection Duality Theorem and Edmonds' Matroid Polyhedral Intersection Theorem.
Fertility of rainbow trout males relative to differences in the proportion of sperm that binds to a specific antibody

Abstract The surface of rainbow trout (Oncorhynchus mykiss) spermatozoa contains a number of different antigenic sites. The objective of this study was to examine the relationship between the relative fertility of different males and the proportion of their sperm that binds to a sperm-specific antibody, Antibody binding to the surface of sperm cells was detected by indirect immunofluorescence using a fluorescein isothiocyanate-conjugated secondary antibody. The sperm-specific antibody, FS101, bound to an average of 42.1% of the spermatozoa obtained from eight males; the proportion of sperm cells which bound the antibody was significantly different among males (***P
Comment on: Evidence for strong electronic correlations in the spectra of Sr2RuO4

It is pointed out that $\mathrm{O}\phantom{\rule{0.2em}{0ex}}2p$ states dominate the electronic structure of ${\mathrm{Sr}}_{2}\mathrm{Ru}{\mathrm{O}}_{4}$ in the $\ensuremath{\sim}\ensuremath{-}3\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ region and can explain the observation of a peak in the density of states in photoemission experiments. This contradicts claims that a lower Hubbard band is needed at $3\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ binding energy.
An ephemeral sex pheromone of female house mice (Mus domesticus): Pheromone fade-out time

Abstract Male mice will emit ultrasounds to at least two chemosignals present in female mouse urine: a) an ephemeral unconditioned stimulus (UCS) present in freshly voided urine and b) a conditioned stimulus (CS) that remains after the UCS has disappeared. In this study, four phases examined the time frame over which the UCS disappeared. Urine that had been aged for either 12, 15, 18, or 24 h was compared for vocalization elicitation with fresh urine (which contains the UCS) and metabolic cage-collected urine (which does not). Under the conditions utilized, significant pheromone fade-out occurred between 15 and 18 h.
A Contribution to the Theory of Business Cycles

An economy consisting of identical perfectly competitive firms with real liquidity costs and a one-period production lag has a locally unstable stationary equilibrium with complex eigenvalues for a wide range of parameters. Monetary policy aimed at stabilizing real balances can support nonstationary equilibrium paths that converge to a limit cycle, which has Keynesian features. The First Welfare Theorem does not hold because the price level appears in the production function through liquidity costs, so that production has a positive externality.
Evidence of an association between 6q13-21 chromosome aberrations and locally aggressive behavior in patients with cartilage tumors

BACKGROUND The finding of a cytogenetic-pathologic correlation between complex karyotypes and high grade cartilaginous tumors has been reported. However, few cytogenetic reports exist regarding benign or low grade lesions. A subset of low grade malignant cartilaginous tumors is characterized by locally aggressive behavior but no metastatic potential. Because the histopathologic distinction between benign, borderline, or low grade malignant cartilaginous lesions can be difficult, the finding of additional tumor markers associated with the clinical behavior of borderline cartilaginous lesions could be clinically significant. METHODS Four cartilaginous tumors, including an osteochondroma (OC), a chondromyxoid fibroma (CF), an enchondroma (EC), and a dedifferentiated chondrosarcoma (DCS), were cultured and harvested using short term, in situ culture techniques. Chromosome analysis was performed by conventional G-banding and fluorescence in situ hybridization was used to confirm G-banding. RESULTS The stemlines of all four tumors showed multiple chromosome anomalies that included aberrations of 6q13-21. The OC showed a t(6;16)(q21;p13.3). The CF showed a complex rearrangement between the chromosome 6 homologues, resulting in an inv(6)(p25q23)t(6;6)(q23;q13). This tumor also showed the clonal evolution of telomeric associations resulting in duplications, deletions, and the formation of a ring 15. The EC showed a der(6)t(6;15)(q13;q11)t(15;22)(q22;q13) stemline and subclones with an unstable iso 17q that subsequently fused to both ends of chromosome 16. The DCS showed a del(6)(q13), r(9), +12 stemline. CONCLUSIONS The cytogenetic findings of this study suggest the cytogenetic-pathologic correlation of complex karyotypes found in high grade cartilage tumors may extend to lower grade tumors with complex karyotypes. These findings further suggest that chromosome aberrations in the region of 6q13-21 may be associated with locally aggressive behavior in patients with cartilage tumors. Cancer 1998;82:474-83. © 1998 American Cancer Society.
Review of "Evaluation of university professors' research performance by Jauch, Lawrence R.; and Glueck, Wiliam F." Management Science 22, 1 (Sept. 1975), 66-75.

The "in house" computer shop can measure its performance against what it did in previous periods. This activity lncludes the gathering of key criteria of performance and its comparison in a variety of ways. This is called "trend analysis." The difficulty experienced in gathering this kind of data suggests that few have reflected on the key items pertaining to the nature of data processing. Thus, definitions are offered for 7 quantitative criteria and suggestions are made for 2 or 3 qualitative indicators of computer performance.
Influence functions for rank-based procedures in the linear model

Throughout the development of rank-based methods, the influence function has often been ignored. In this paper, we give the influence functions for the scores rank estimate and the corresponding drop test (based on the difference in dispersion between the full and reduced fits). We show how the influence function measures resistance of the estimator to contamination and how proper score selection leads to more resistant procedures. Furthermore, the asymptotic distribution of the estimator and test can be inferred from the influence function. We also introduce the drop test statistic for the weighted rank-based procedure of Naranjo and Hettmansperger. This test statistic has an influence function that is bounded in both x and y space, and reduces to the regular rank dispersion test using Wilcoxon scores in the unweighted case.