cssi/SciSciGPT-SciSciNet huggingface dataset:
Alkaline phosphatase activity in cultured meningioma cells.

The specific activity of alkaline phosphatase in cultured human meningioma cells varies over a relatively wide range. There is no correlation between the levels of activity and the histological type of meningioma from which the cultures were derived. The enzyme is heat-labile and is strongly inhibited byl-homoarginine, levamisole, and l-bromotetramisole, but unaffected byl-phenylalanine andl-phenylalanylglycylglycine. These findings indicate that meningioma cells synthesize the liver/bone/kidney form of alkaline phosphatase. In contrast to cultures derived from pituitary adenomas, glioblastomas, and astrocytomas in which prednisolone and/or sodium butyrate elicit a manifold increase of alkaline phosphatase activity, with meningioma cells the hormone causes only a slight augmentation in specific activity, and the fatty acid is ineffective. As with other cells producing the liver/bone/kidney enzyme form, no increase in activity occurs in meningioma cells growing in hyperosmolar medium.
Dichotic beats of mistuned consonances

Temporal envelope perception, aural harmonics, and combination tones have all been proposed as mechanisms to explain the beats of mistuned consonances (BMC). This study used dichotic presentation of mistuned octaves to explore a between‐channel temporal explanation. A 2I‐2AFC procedure was employed to determine subjects’ ability to detect BMC. Masking in dichotically complementary frequency regions was used to eliminate effects caused by aural harmonics and acoustic crossover. Subjects were able to detect dichotic BMC under these conditions. Performance deteriorated with an increase in fundamental frequency as expected from previous studies on monotic BMC and on binaural beats. Envelopes of pairs of beating sinusoids were used to further explore the temporal basis of BMC. Subjects were able to detect mistuned consonant envelopes for both monaural and dichotic presentation. A third experiment examined the detection of the ‘‘sweep‐tone’’ pitch effect using the same stimuli. The results of these experiments will be discussed in terms of within‐ and between‐channel phase perception. [Research supported by the Virginia Merrill–Bloedel Hearing Research Center, University of Washington.]
N-terminal Sequences Contained in the Src Homology 2 and 3 Domains of p120 GTPase-activating Protein Are Required for Full Catalytic Activity Toward Ras

The p120 GTPase-activating protein (GAP) is a negative regulator of Ras, which has a central role in signal transduction pathways that control cell proliferation. p120 GAP accelerates the conversion of activated Ras-GTP to its inactive form, Ras-GDP, thereby inhibiting mitogenic signaling. To examine potential contributions of p120 N-terminal sequences to regulation of its C-terminal catalytic domain, we constructed deletion mutants lacking defined regions, including the variable hydrophobic region as well as the Src homology 2 (SH2) and 3 (SH3) domains. These mutant proteins were expressed in infected Sf9 insect cells from recombinant baculoviruses and assayed in vitro for their ability to stimulate the intrinsic GTPase activity of purified Ras. While deletion of the variable hydrophobic region had no effect on p120 GAP activity, deletion of the entire SH2/SH3/SH2 region severely impaired catalytic activity toward Ras. Deletion of individual SH2 and SH3 domains within this region partially inhibited p120 GAP activity. Moreover, p120 N-terminal sequences enhanced the Ras GTPase-stimulating activity of the neurofibromin GAP-related domain. These results demonstrate that sequences in the SH2/SH3/SH2 region of p120 GAP are required for full catalytic activity toward Ras. Together with earlier findings that the p120 GAP SH2 domains mediate interactions with several GAP-associated proteins, our results suggest multiple roles for the N-terminal sequences in regulating p120 GAP catalytic activity and mitogenic signaling pathways. In addition, our results raise the possibility that SH2 domain point mutations in p120 GAP detected in some basal cell carcinomas reduce catalytic activity toward Ras and thereby contribute to oncogenesis.
Ultrastructure of trichocyte (hair cell) complexes in Jania adhaerens (Corallinales, Rhodophyta)

Trichocyte complexes of Jania adhaerens (Corallinales, Rhodophyta) were studied by scanning and transmission electron microscopy. The trichocyte complex is composed of trichocytes (hair cells), their associated initial cells, and a previously unknown ephemeral cell, here termed the crown cell. The crown cell, which is part of the epithallial layer, is the original apical cell of each filament forming a trichocyte complex. The trichocyte initial divides to produce both a trichocyte devoid of chloroplasts and a subtending cell that serves as the initial cell for the next trichocyte generation (secondary trichocyte initial). A hair growing from the apical end of the trichocyte passes through a collar of distinctive wall material deposited originally around the apical end of the primary trichocyte initial and the base of the crown cell. The first hair passing through this channel destroys the crown cell before emerging from the thallus surface. The cytoplasm of hair-bearing trichocytes is particularly rich in Golgi vesicles. After the hair is lost and as the trichocyte base degenerates, the secondary trichocyte initial enlarges, filling the chamber that formerly housed both the initial and the trichocyte. The pit plug and crosswall that had been shared by the initial cell and the senescent trichocyte are pushed aside and compressed by the enlarging initial. These wall structures persist between the initial cell and the surrounding calcium carbonate wall. The enlarged secondary initial cell either becomes quiescent, persisting in the undivided state and being equivalent to a megacell or heterocyst, or it divides, producing a new trichocyte and initial. Remnants of more than 20 generations of walls and pit plugs were observed within the chambers of some trichocyte complexes. These wall remnants potentially provide a record of every cycle of regeneration of each trichocyte produced over the life of the alga.
Rechargeable Lithium Battery Cathodes. Nonaqueous Synthesis, Characterization, and Electrochemical Properties of LiCoO2

A nonaqueous coprecipitation process has been developed to prepare controlled stoichiometry lithium cobalt oxide precipitates. The process involved mixing a methanolic “LiCo(NO3)3” solution with a methanolic solution containing tetramethylammonium oxalate as a precipitating agent. The resulting oxalates were readily converted to phase-pure lithium cobalt oxide at 800 °C under an oxygen atmosphere. The various starting solutions, oxalate precipitates, and the resulting oxides have been extensively characterized using a variety of techniques, including multinuclear NMR, TGA/DTA, EPR, and XRD analyses. Results indicate that the strong interaction between the metals (Li and Co) that occurred in solution was maintained during precipitation. The calcined precipitate revealed that the desired LiCoO2 phase was formed at 800 °C under an O2 atmosphere. When electrochemically cycled, the material exhibited an initial capacity of ∼133 (mA h)/g with a fade of 0.02% in capacity per cycle.
The reflection of logistics in electronic computer design

Analytical and operational logistics seem, at first glance, to require widely differing computational tools. When one looks more deeply into typical undertakings in logistics, including such varied activities as: fundamental logistics research, the playing of war games, production scheduling, and the determination of supply requirements, appropriate computational techniques do not appear to require markedly differing computational facilities. If differences are deemed essential, they appear to lie in accessibility of storage and the nature and extent of peripheral equipment rather than in the basic organization and mathematical power of the central computer. Representative problems in varied aspects of logistics are discussed briefly. An appropriate mathematical model is displayed, in each case, with perhaps a heuristic derivation, and is viewed from the standpoint of the computational facilities it requires. New applications of electronic computers, such as the mechanical translation of languages and information retrieval (now in the exploratory stage), which promise to have significant logistical implication, are discussed briefly.
Generalized Uncertainty Principles on Spaces of Homogeneous Type

We describe a generalized version of Weyl′s principle and of the Heisenberg uncertainty principle under which the geometry and spectral theory of a given operator can be tied together to the geometry of its underlying space. This is achieved by means of multiscale analysis performed on the associated space of homogeneous type. In this paper we consider in detail the case of (−Δ)ϵ/2 on compact manifolds.
Violence in the Mass Media: A Case of Modelling

A case study of the modelling effects of the news media in reporting an unusual act of violence is presented. Using the naturalistic unobtrusive methodology, the double assassination attempts on President Gerald Ford in September 1975 resulted in an increase in the number of assassination threats for several months threafter. The implications were discussed. Language: en
Status of coal ash behavior research

The inorganic components contained in coal are converted to ash during combustion and gasification. The resulting ash can cause significant problems that include slag flow behavior, ash deposition, bed agglomeration, corrosion and erosion of system parts, fine particulate that is difficult to collect, and blinding of hot-gas cleanup filters. The type of problem and the degree of the problem are dependent upon coal composition, system operating conditions, and system design criteria. Much research has been conducted on ash formation and behavior in pulverized coal- and cyclone-fired utility boilers. Many of the mechanisms of transformations and ash deposition have been worked out, and predictive models have been developed. Ash behavior research in fluidized-bed combustion systems has been conducted to determine the effects of coal quality and operating conditions on bed agglomeration and deposition on heat-transfer and other surfaces. Ash can also influence gasification system operability. Problems such as maintaining slag flow and ash deposition have been encountered. In advanced power systems, hot-gas cleanup is a significant issue in which ash plays a significant role. The issues in hot-gas cleanup include ash deposition on filters, ash removal, and vapor-phase and ash-ceramic interactions. The chemical and physical characteristics of the ash also influence their ability to be collected in air pollution control devices.
Ultrasonically induced degradation and detoxification of microcystin-LR (cyanobacterial toxin)

Cyanobacterial toxins (CBTs), produced by glue-green algae, are one of the most common naturally occurring toxins found in potable waters. The microcystin family of CBTs present in drinking water sources poses a considerable threat to human health. In this study, we have demonstrated that ultrasonic irradiation at 640 kHz leads to rapid degradation of microcystin-LR (MC-LR). Degradation of MC-LR present in the crude cyanobacterial extracts containing cell constituents has been studied with ultrasound under a variety of conditions. The degradation of MC-LR was demonstrated over a concentration range from 0.03 to 3.0 μM. Hydroxyl radical scavenger experiments indicate that hydroxyl radical is responsible for a significant fraction of the observed degradation, but other processes (hydrolysis/pyrolysis) are also important. Analysis of the protein phosphatase inhibition activity of the reaction products indicates that the products from ultrasonic degradation of MC-LR do not exhibit any measurable biological ac...
Interstitial cluster nucleation at the onset of irradiation

Abstract The rate equations for the concentrations of single and small clusters of vacancies and interstitials are investigated during the transient period at the onset of irradiation. For reasonable cluster binding energies, it is found that stable interstitial clusters nucleate homogeneously in high concentrations at the lower temperature range of void swelling and their concentration decreases with increasing temperature. The effect of irradiation rate is similar to that for void swelling: lowering the irradiation rate shifts the concentration curves to lower temperatures. Increasing the concentration of preexisting sinks decreases cluster nucleation, and the cluster concentrations are found to be sensitive to cluster binding energies.
Regularized optimization (RO) reconstruction for oximetric EPR imaging

A new algorithm for EPR imaging oximetry is described and tested with experimental data for the case of one spatial and one spectral dimension. A single species with variable linewidth is assumed. Instead of creating a 2D image, two one-dimensional profiles are reconstructed: the concentration of the radical and the corresponding oxygen concentration, which reduces the dimensionality of the problem. The algorithm (i) seeks to minimize the discrepancy between experimental data and projections calculated from the profiles and (ii) uses Tikhonov regularization to constrain the smoothness of the results. This approach controllably smoothes profiles rather than the data, while preserving sharp features.
Variational method using basis functions

The Gaussian, exponential and Laguerre basis functions are examined in a variational calculation of energies and wavefunctions. The Laguerre basis set is already orthonormal and complete, but the Gaussian and exponential basis sets are not orthonormal. We used the linear and Coulomb potentials to test these basis functions. Calculations are performed in both position and momentum space. We also present the results with relativistic kinematics in the momentum space calculation. The Gram–Schmidt procedure is used to orthonormalize the Gaussian and exponential basis sets before using them in the calculations. We show that in the case of a pure linear potential, the orthonormal basis constructed from the Gaussian functions performs much better than the exponential and Laguerre basis for the same number of orthogonal functions. For Coulomb-like potentials, the exponential basis performs better than the other two for the same number of basis functions. The advantage of using these simple basis functions is that for the potentials that we examined, one can approach the lower bound of the low-lying states with very few basis functions.
Obesity management in gynecologic cancer survivors: provider practices and attitudes.

Objective Obesity is associated with the development and risk of death from several women's cancers. The study objective was to describe and compare oncologic providers' attitudes and practices as they relate to obesity counseling and management in cancer survivors. Study Design Society of Gynecologic Oncology members (n = 924) were surveyed with the use of a web-based, electronic questionnaire. χ 2 and Fisher exact tests were used to analyze responses. Results Of the 240 respondents (30%), 92.9% were practicing gynecologic oncologists or fellows, and 5.1% were allied health professionals. Median age was 42 years; 50.8% of the respondents were female. Of the respondents, 42.7% reported that they themselves were overweight/obese and that ≥50% of their survivor patients were overweight/obese. Additionaly, 82% of the respondents believed that discussing weight would not harm the doctor-patient relationship. Most of the respondents (95%) agreed that addressing lifestyle modifications with survivors is important. Respondents believed that gynecologic oncologists (85.1%) and primary care providers (84.5%) were responsible for addressing obesity. More providers who were ≤42 years old reported undergoing obesity management training ( P 42 years old ( P = .017). After initial counseling, 81.5% of the respondents referred survivors to other providers for obesity interventions. Conclusion Oncology provider respondents believe that addressing obesity with cancer survivors is important. Providers believed themselves to be responsible for initial counseling but believed that obesity interventions should be directed by other specialists. Further research is needed to identify barriers to care for obese cancer survivors and to improve physician engagement with obesity counseling in the "teachable moment" that is provided by a new cancer diagnosis.
Differential modulatory actions of serotonin in Aplysia sensory neurons: implications for development and learning

Abstract We have addressed whether mechanisms of adult plasticity reflect conserved forms of developmental processes by comparing the effects of serotonin (5HT) in juvenile and adult Aplysia sensory neurons. We show that the effects of 5HT can be dissociated into two functional classes which (i) contribute differentially to short- and long-term synaptic plasticity in adults and (ii) emerge differentially during development. We propose a model in which one class of mechanism mediates structural changes early in development and is retained in the adult to subserve long-term memory, while the second class develops late and contributes only to short-term memory in the adult.
Exhaustive test pattern generation using cyclic codes

The generation of exhaustive test patterns for VLSI circuits using linear feedback shift registers is described in terms of cyclic codes. Punctured cyclic codes are used to generate exhaustive test patterns of any length. A techniques for the generation of punctured cyclic codes is presented. A technique is also presented to reduce the size of test sets obtained from punctured cyclic codes. >
High-Pressure Stability in Ordered Mesoporous Silicas: Rigidity and Elasticity through Nanometer Scale Arches

High-pressure, low-angle X-ray diffraction is used to examine the compressibility of periodic hexagonal, surfactant-templated silicas. Mesoscopic order in these materials can be retained up to 12 GPa, and pressure-induced distortions are reversible. Postsynthetic treatments can greatly enhance the mechanical properties of these nanostructured materials. Bulk moduli equal to and even higher than values measured for bulk vitreous silica are obtained if both the nanometer-scale order and local atomic-scale bonding are optimized. The results show that common architectural motifs, such as the arch or the honeycomb structure, can be used to produce rigidity and elasticity without excessive mass in materials with periodicity down to mere nanometers.
Prosimian learning capacities

Abstract A survey of the literature on learning by prosimian primates contradicts a traditional view that they are untrainable. They learn simple operants such as bar pressing readily, work well for the usual rewards, and respond in predictable fashion on schedules of partial reinforcement. Two-dimensional visual discriminations involving pattern and brightness also are learned, as are three-dimensional object discriminations. In the area of complex learning, they not only acquire a variety of difficult tasks, but they also reach a final level of performance that is at or near the level of anthropoids. In each of the following areas, at least one experiment is described in which a prosimian species did as well as one or more anthropoid species: object discrimination learning set, discrimination reversal, delayed response, instrumentation, oddity, and relational problems. The anthropoids to which they are most apt to compare favorably are New World monkeys, a group which they resemble physically, especially with respect to degree of manipulativeness, cortical development, and visual acuity.
Crohn's Disease of the Small Bowel

Crohn's disease of the small bowel frequently requires surgical intervention. While dealing with the disease complications that require intervention, treatment should be based on a long-term strategic plan that recognizes the likelihood of recurrent disease, repeat surgeries, and the possibility of a future ostomy. Resection forms the basis for surgical treatments, but strictureplasty, abscess drainage, intestinal and diversion bypasses also are used, selectively.
Topographic and compositional influences on disturbance patterns in a northern Maine old-growth landscape

Disturbance patterns are strongly coupled with forest composition and structure, and patterns change through time in response to shifts in climate, anthropogenic impacts and other factors. Knowledge of the natural disturbance patterns for establishing baseline conditions for a forest type or ecosystem facilitates change detection for other elements of the biophysical system important to management and conservation. Dendrochronological reconstructions from old-growth forest remnants throughout northeastern North America document average decadal rates of disturbance of 5%‐<10% over the last 150‐300 years. Relatively frequent, low severity disturbance characterized by small gaps representing canopy openings madeby1‐3treesprevailintheseforestsdominatedbyvaryingmixturesoflate-successionaltreespecies. Few studies, though, have explicitly characterized differences related to composition or topographic setting in old-growth landscapes. We addressed this by comparing the temporal and spatial disturbance patterns reconstructed from tree rings at two spatial resolutions (0.5ha and 200m 2 ). Sites were selected to assess the influence of topography (slope) and cover type in stands where red spruce (Picea rubens Sarg)andbalsamfir(AbiesbalsameaL.Mill)werekeycomponents.Lowratesofdisturbance(average<10% per decade) and small gap sizes ("30m 2 ) prevailed in all stands during the decades from 1850‐1980. Episodic pulses of disturbance, of nearly moderate intensity in some stands, opened ca. 20‐30% of the canopy area and were associated with wind events and/or insect outbreaks that differentially affected stands. We found no significant difference in the average temporal rates of disturbance related to cover type or topography in 0.5-ha plots. However, the influence of these factors was evident in comparisons of gap areas estimated for 200-m 2 plot sections. At this resolution, the largest canopy openings (#100m 2 )
Comparative Effects of Fructose and Glucose on Lipogenic Gene Expression and Intermediary Metabolism in HepG2 Liver Cells

Consumption of large amounts of fructose or sucrose increases lipogenesis and circulating triglycerides in humans. Although the underlying molecular mechanisms responsible for this effect are not completely understood, it is possible that as reported for rodents, high fructose exposure increases expression of the lipogenic enzymes fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC-1) in human liver. Since activation of the hexosamine biosynthesis pathway (HBP) is associated with increases in the expression of FAS and ACC-1, it raises the possibility that HBP-related metabolites would contribute to any increase in hepatic expression of these enzymes following fructose exposure. Thus, we compared lipogenic gene expression in human-derived HepG2 cells after incubation in culture medium containing glucose alone or glucose plus 5 mM fructose, using the HBP precursor 10 mM glucosamine (GlcN) as a positive control. Cellular metabolite profiling was conducted to analyze differences between glucose and fructose metabolism. Despite evidence for the active uptake and metabolism of fructose by HepG2 cells, expression of FAS or ACC-1 did not increase in these cells compared with those incubated with glucose alone. Levels of UDP-N-acetylglucosamine (UDP-GlcNAc), the end-product of the HBP, did not differ significantly between the glucose and fructose conditions. Exposure to 10 mM GlcN for 10 minutes to 24 hours resulted in 8-fold elevated levels of intracellular UDP-GlcNAc (P<0.001), as well as a 74–126% increase in FAS (P<0.05) and 49–95% increase in ACC-1 (P<0.01) expression above controls. It is concluded that in HepG2 liver cells cultured under standard conditions, sustained exposure to fructose does not result in an activation of the HBP or increased lipogenic gene expression. Should this scenario manifest in human liver in vivo, it would suggest that high fructose consumption promotes triglyceride synthesis primarily through its action to provide lipid precursor carbon and not by activating lipogenic gene expression.
Attenuation Deforms Time-intensity Curves During Contrast Echocardiography: Implications for Assessment of Mean Transit Rates

The mean transit rate of microbubbles of air obtained from time-intensity curves during contrast echocardiography can be used to evaluate flow through a vascular system, provided the volume of distribution of the system remains constant. We hypothesized that attenuation commonly associated with contrast echocardiography distorts the time-intensity curves, producing an error in the estimation of the mean transit rate of the microbubbles. The purpose of this study was to characterize this distortion with computer simulations and to study the effect of attenuation on the estimation of mean transit rate in an in vitro experiment. We also sought to determine if removing the data points from the time-intensity plots that visually can be attributed to attenuation before curve fitting can minimize the error in the estimation of mean microbubble transit rate. In both computer simulations and experimentally acquired in vitro data, attenuation distorted the time-intensity curves, producing an underestimation of mean microbubble transit rates. The mean microbubble transit rate decreased with an: increase in microbubble concentration. Removing the points that visually were attributed to attenuation before curve fitting did not correct this error completely in the computer-simulated data and failed to correct it at all in the experimental data. These results have major practical implications in assessing mean microbubble transit rates during contrast echocardiography.
A flow-reactor mass-spectrometer investigation of the initiation steps of the O(3P) atom reaction with benzene

The paper demonstrates phenoxy to be a primary product of the O-atom benzene reaction around 405 K
Speckle reduction in optical coherence tomography images via dynamic infinite-impulse-response filtering

A temporal filtering method based on an infinite-impulse-response filter is presented to reduce speckle in optical coherence tomography (OCT) images. This method works in a recursive way, linearly combining the current B-scan image frame with a previously filtered one to generate a newly filtered image. Thus, it performs with less computational complexity and time, compared to the finite-impulse-response filter based approach that typically averages multiple stored frames. To achieve speckle noise reduction while avoiding image blurring caused by sample motion, the filter coefficient is dynamically determined, depending on the parameters related to motion detection and image quality. We used the mean-squared error (MSE) between two successive frames as a criterion to detect sample motion and changed the filter coefficient when the MSE exceeded a certain threshold to prevent image blurring. The optimal coefficient and motion detection threshold were chosen for achieving robust and unblurred images in our testbed configuration. In this study, we analyzed the algorithm with OCT images acquired by a swept-source OCT system we built and also examined that the method operated in real-time even via CPU processing. Results in our and conventional schemes are compared by using various image quality metrics and by observing images. We found that the performance of speckle reduction was quite promising and simultaneously the fine details of sample structures were preserved even with sample motion.
Reversible formation of an intramolecular agostic CH interaction in a dimanganese complex

Agostic interactions of CH bonds with metal atoms are currently of great interest. UV irradiation of Mn2(CO)8 (PMe2Ph)2 in the presence of the HC≡COEt yielded the new compound Mn2(CO)6(PMe2Ph)2 [μ-C(OEt)=C(H)C=C(H)C=O(OEt)],1 that contains a strong agostic interaction of an olefinic CH bond to one of the managanese atoms, Mn...C=2.349(5), Mn...H=2.01(4). This interaction can be removed (reversibly) by CO addition (25°C/1000 psi) to1 to yield the new complex Mn2(CO)7(PMe2Ph)2[μ-C(OEt)=C(H)C=C(H)C=O(OEt)],2.
Downregulation of Prdm16 mRNA is a specific antileukemic mechanism during HOXB4-mediated HSC expansion in vivo

Overexpression of HOXB4 in hematopoietic stem cells (HSCs) leads to increased self-renewal without causing hematopoietic malignancies in transplanted mice. The molecular basis of HOXB4-mediated benign HSC expansion in vivo is not well understood. To gain further insight into the molecular events underlying HOXB4-mediated HSC expansion, we analyzed gene expression changes at multiple time points in Lin(-)Sca1(+)c-kit(+) cells from mice transplanted with bone marrow cells transduced with a MSCV-HOXB4-ires-YFP vector. A distinct HOXB4 transcriptional program was reproducibly induced and stabilized by 12 weeks after transplant. Dynamic expression changes were observed in genes critical for HSC self-renewal as well as in genes involved in myeloid and B-cell differentiation. Prdm16, a transcription factor associated with human acute myeloid leukemia, was markedly repressed by HOXB4 but upregulated by HOXA9 and HOXA10, suggesting that Prdm16 downregulation was involved in preventing leukemia in HOXB4 transplanted mice. Functional evidence to support this mechanism was obtained by enforcing coexpression of sPrdm16 and HOXB4, which led to enhanced self-renewal, myeloid expansion, and leukemia. Altogether, these studies define the transcriptional pathways involved in HOXB4 HSC expansion in vivo and identify repression of Prdm16 transcription as a mechanism by which expanding HSCs avoid leukemic transformation.
Crossing over frequency following inbreeding inNeurospora

Crossing over frequency was determined for five marked regions covering most of a chromosome arm. The results of a 12th backcross were compared with previously published results from the noninbred f1. Exchange frequency increased significantly following inbreeding. Chiasma interference remained positieve, but was somewhat less intense in b12.
The power law as an emergent property.

Recent work has shown that the power function, a ubiquitous characteristic of learning, memory, and sensation, can emerge from the arithmetic averaging of exponential curves. In the present study, the forgetting process was simulated via computer to determine whether power curves can result from the averaging of other types of component curves. Each of several simulations contained 100 memory traces that were made to decay at different rates. The resulting component curves were then arithmetically averaged to produce an aggregate curve for each simulation. The simulations varied with respect to the forms of the component curves: exponential, range-limited linear, range-limited logarithmic, or power. The goodness of the aggregate curve’s fit to a power function relative to other functions increased as the amount of intercomponent slope variability increased, irrespective of componentcurve type. Thus, the power law’s ubiquity may reflect the pervasiveness of slope variability across component functions. Moreover, power-curve emergence may constitute a methodological artifact, an explanatory construct, or both, depending on the locus of the effect. John Wixted, and Steven Sloman, for their helpful comments on the manuscript.
The effect of a manganese deficiency in the chick on the uptake of inorganic phosphate by liver homogenates in vitro

Abstract The phosphate uptake by chick liver homogenates fed adequate, manganese- and/or choline-deficient diets has been determined by in vitro procedures. The effect of either a manganese or of a choline deficiency was to reduce the amount of phosphate esterified. Further studies with manganese-deficient liver homogenates gave the following results: 1. 1. The addition of Mn++ failed to stimulate phosphate uptake. In fact, an inhibition was observed when as little as 0.0005 M Mn++ was added to mixtures which contained either control or deficient liver homogenates. 2. 2. The reduced activity was not obviated when different Krebs cycle intermediates were used to replace succinate in the reaction mixture, such as citrate, pyruvate, and α-ketoglutarate each in combination with fumarate. 3. 3. The rate of 7-min. hydrolyzable phosphate formation was nearly equal to the rate observed with the control livers for each substrate except the citrate-fumarate combination which was less effective with the deficient liver than with the control liver. 4. 4. The addition of cytochrome c to the reaction mixture failed to stimulate phosphorylation, while a good response was shown by adding cytochrome c to the control homogenates.
Gen(om)e duplications in the evolution of early vertebrates

Phylogenetic analyses and sequence surveys of developmental regulator gene families indicate that two large-scale gene duplications, most likely genome duplications, occurred in ancestors of vertebrates. Relaxed constraints allowed duplicated and thus redundant genes to diverge in a two stage mechanism. Neutral changes dominated at first but then positively selected regulatory changes evolved the novel and increasingly complex vertebrate developmental program.
Rule abstraction, item memory, and chunking in rat serial-pattern tracking

Two studies used a stimulus tracking paradigm to test whether rats are sensitive to the rule-based formal properties of structured serial patterns. Hooded rats tracked 16-element patterns of flashing lights by pressing levers under an array of 6 indicator lights. In Experiment 1, rats tracked a pattern similar to one previously used with human subjects and yielded remarkably similar results. More errors and response omissions occurred at boundaries of structural "chunks" than within chunks, and errors often reflected anticipation of the next chunk or extrapolation of the preceding chunk. In Experiment 2, temporal "phrasing" cues encouraged different groups to encode a pattern as a series of either "runs" or "trills." Differential placement of pauses induced rats to encode different rule-based representations of the pattern. Results indicate that under appropriate conditions rats may encode a representation of formal structure when they learn organized response patterns.
Is nuclear fission acceptable

Abstract Fossil fuels, including coal, oil and gas, cannot be counted upon as a major energy fuel resource over a long time period. Given that energy utilisation patterns will not alter from those presently characteristic then only three potential fuel sources currently appear adequate to meet the large part of future requirements. These are solar, nuclear fusion and nuclear fission energy. Of these, nuclear fusion energy remains technically unproved. In the highly developed world nuclear fission appears to have been chosen as the major future energy resource. But many would hold that promotional opportunism of the nuclear establishment rather than merit has served as the basis for this choice.
Complications of implantable venous access devices in patients with sickle cell disease

Implantable venous access devices (VADs) are used in sickle cell disease (SCD) for patients with poor venous access to facilitate chronic blood transfusions and manage acute complications. We attempted to define the frequency of bloodstream infections (BSI) and thrombosis in adults and children with SCD and VADs. We performed a single-institution, retrospective review of VAD-associated infection and thrombosis in patients with SCD. Thirty-two patients (median age 20 years, range, 1-59) had 86 VADs placed (median, 2.7 VADs per patient, range, 1-7) with a total of 41,292 catheter days (median, 1,376 days; range, 323-3,999). Mean catheter lifespan in adults (691 days ± 123) was not significantly higher than children (614 days ± 154). A total of 66 VAD-associated BSI (1.59 infections per 1,000 catheter days) occurred in 17 of 32 (53%) patients. Children with VADs had fewer BSI (3 of 10; 30%) than adults (14 of 22; 64%, P = 0.08). 24 catheter-associated thromboses (0.49 thromboses per 1,000 catheter days) occurred in 10 of 32 (41%) of patients. Children also had fewer VAD-associated-thrombosis (1 of 10; 10%) than adults (9 of 22; 40%, P = 0.08). In conclusion, the use of VADs in SCD was linked to a significant rate of infection and thrombosis.
Synthesis of a nuclear protein in G2-phase

Abstract A specific extraction procedure for proteins present in isolated nuclei of the slime mold Physarum polycephalum is described. This extraction procedure yields more than 90% of the nuclear proteins with less than 12% polysaccharide. Gel electrophoresis of nuclear extracts from S- and G2-phase nuclei revealed no significant differences in the densitometer tracings of the stained bands. The synthesis of at least one nuclear protein almost exclusively in G2 phase could be demonstrated when nuclear extracts from plasmodia labeled with 14C-amino acids were used for electrophoresis with subsequent fractionation of the gels. The molecular weight of this protein was determined to be about 42,000.
Marital conflict and disruption of children's sleep

Marital conflict was examined as a predictor of the quality and quantity of sleep in a sample of healthy 8- to 9-year-olds. Parents and children reported on marital conflict, the quantity and quality of children's sleep were examined through an actigraph worn for 7 consecutive nights, and child sleepiness was derived from child and mother reports. Increased marital conflict was associated with disruptions in the quantity and quality of children's sleep as well as subjective sleepiness, even after controlling for child age, ethnic group membership, socioeconomic status, sex, and body mass index. The results support the sensitization hypothesis in that exposure to marital conflict may influence an important facet of children's biological regulation, namely sleep.
Free-solution interaction assay of carbonic anhydrase to its inhibitors using back-scattering interferometry

Back-scattering interferometry (BSI) is a label-free, free-solution, small-volume technique used for characterizing binding interactions, which is also relevant to a growing number of biosensing applications including drug discovery. Here we use BSI to characterize the interaction of carbonic anhydrase (CAII) with five well known CAII inhibitors (±sulpiride, sulfanilamide, benzene sulfonamide, dansylamide, and acetazolamide) in the presence of dimethyl sulfoxide (DMSO). Dissociation constants (KD) calculated for each interaction were consistent with literature values previously obtained using surface plasmon resonance (SPR) and fluorescence-based competition assays. Results demonstrate the potential of BSI as a drug-screening tool which is fully-compatible with DMSO and does not require immobilization or labeling, therefore allowing binding interactions to be characterized in the native state. BSI has the potential for reducing labor costs, sample consumption and assay time while providing enhanced reliability over existing techniques.
Concordance of patient and family report of neurobehavioral symptoms at 1 year after traumatic brain injury.

Abstract Hart T, Whyte J, Polansky M, Millis S, Hammond FM, Sherer M, Bushnik T, Hanks R, Kreutzer J. Concordance of patient and family report of neurobehavioral symptoms at 1 year after traumatic brain injury. Arch Phys Med Rehabil 2003;84:204-13. Objective: To determine concordance between patient and family report of neurobehavioral symptoms and problems across 6 domains of function and 3 levels of injury severity at 1 year after traumatic brain injury (TBI). Design: Prospective longitudinal design with follow-up between 10 and 14 months postinjury. Setting: Seventeen Traumatic Brain Injury Model Systems centers. Participants: A total of 267 adults with primarily moderate and severe TBI who had completed self-ratings and whose neurobehavioral symptoms had also been rated by their significant others. Interventions: Not applicable. Main Outcome Measures: Neurobehavioral Functioning Inventory[ndash ]Revised, a 70-item scale with subscales assessing frequency of symptoms in motor, somatic, memory and attention, depression, communication, and aggression domains. Results: Twenty-three items showed significant differences or trends between the self- and other ratings; 18 of these were in the direction of the injured individual reporting less frequent problems. Differences were most pronounced on the depression, aggression, and memory and attention subscales. On the latter 2 subscales, patient-family concordance was higher for those with less severe injuries. However, severity effects were not clear cut. Analyses of selected rating patterns indicating clinically significant [ldquo ]underreporting[rdquo ] of symptoms revealed that these affected the depression, aggression, and memory and attention subscales more than the motor or somatic subscales. Conclusions: At 1 year post-TBI, concordance between self- and other report of neurobehavioral symptoms was moderately high overall, but varied by symptom domain. For persons with moderate and severe TBI, reports from significant others may be needed for a full picture of the range, severity, and clinical importance of the patient's emotional, behavioral, and cognitive difficulties. [copy ] 2003 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation
Economic Considerations Relative to Water Quality

Our immense national water quality control program has been launched on a wholly empirical basis, much as our ancestors initiated early navigation improvements and flood control. Not only has there been no effort to determine the benefits of water quality control; the theoretical groundwork for optimization has not been developed. Three main national objectives for consideration are national economic efficiency, preserving and improving the national environment for man's use and development (conservation), and regional development. Although popular at present, the regional development objective is not particularly useful from an economic viewpoint. Efficiency objectives other than environmental can be evaluated but are apt to be minor. Other water quality benefits can be broken down appropriately into four main categories: (a) man's recreational environment; (b) man's home environment; (c) man's working environment; (d) intangibles related to scientific, historic, health and cultural values. In management of water quality, various technical relationships must be considered, particularly as to quantity of water needed for waste disposal, and relationship of this use to water supply withdrawals. Advanced waste treatment must be compared with other alternatives, not only of flow augmentation, but also technological process changes, distribution of effluents, and artificial river aeration.
A hybrid finite‐element formulation for analyzing systems of beams and plates in the midfrequency range

A hybrid finite‐element analysis (hybrid FEA) formulation has been developed in the past for computing the midfrequency vibration of systems that contain one type of energy. The hybrid FEA is based on characterizing as long members in a system all the members that contain a large number of wavelengths within their dimension. All the remaining members are considered as short. The Energy Finite‐Element Analysis (EFEA) is employed for modeling the behavior of the long members, while the conventional FEA method is utilized for modeling the short members. In this paper the hybrid FEA formulation is extended to plate structures that are spot‐welded to a frame comprised by tubular members. The new formulation is validated by comparing the hybrid FEA solution to results produced by very dense conventional FEA models in the mid‐frequency range. [Research supported by the Automotive Research Center, US. Army.]
Impact of Organizational Culture and Technology on Firm Performance in the Service Sector

This study focuses on the way organizational culture is adopted for exploring the relationship of firm performance. The primary objective is to explore the relationship between organizational culture and information technology effectiveness with reference to firm performance. The performance of the firm was measured using the dependent variables, return on assets (ROA) and Earning Per Share (EPS), obtained from the annual reports of the listed services industries in Nigeria. The random sample generated 200 usable responses. All the four cultural types adopted in the study had influence on the return on assets and earnings per share. The result of the Pearson correlation analysis revealed that masculinity culture factor was the most positively related to organizational culture and technology capability. The result provided evidence regarding the implications of organizational cultures as well as enabling factors associated with firm’s performance and firm’s innovativeness. The study increases our conceptual understanding of the variation and content of organizational culture, and technology. We recommended that management should consider developing the conducive organizational culture that requires the culture of openness, collaboration, trust, autonomy and authenticity. The study also recommended that future research be conducted utilizing larger sample size.
Automatic language identification of telephone speech messages using phoneme recognition and N-gram modeling

The paper compares the performance of four approaches to automatic language identification (LID) of telephone speech messages: Gaussian mixture model classification (GMM), language-independent phoneme recognition followed by language-dependent language modeling (PRLM), parallel PRLM (PRLM-P), and language-dependent parallel phoneme recognition (PPR). These approaches span a wide range of training requirements and levels of recognition complexity. All approaches were tested on the development test subset of the OGI multi-language telephone speech corpus. Generally, system performance was directly related to system complexity, with PRLM-P and PPR performing best. On 45 second test utterances, average two language, closed-set, forced-choice classification performance reached 94.5% correct. The best 10 language, closed-set, forced-choice performance was 79.2% correct. >
Cache-conscious structure definition

A program's cache performance can be improved by changing the organization and layout of its data---even complex, pointer-based data structures. Previous techniques improved the cache performance of these structures by arranging distinct instances to increase reference locality. These techniques produced significant performance improvements, but worked best for small structures that could be packed into a cache block.This paper extends that work by concentrating on the internal organization of fields in a data structure. It describes two techniques---structure splitting and field reordering---that improve the cache behavior of structures larger than a cache block. For structures comparable in size to a cache block, structure splitting can increase the number of hot fields that can be placed in a cache block. In five Java programs, structure splitting reduced cache miss rates 10--27% and improved performance 6--18% beyond the benefits of previously described cache-conscious reorganization techniques.For large structures, which span many cache blocks, reordering fields, to place those with high temporal affinity in the same cache block can also improve cache utilization. This paper describes bbcache, a tool that recommends C structure field reorderings. Preliminary measurements indicate that reordering fields in 5 active structures improves the performance of Microsoft SQL Server 7.0 2--3%.
Image-guided placement of port catheters: is there an increased risk of infection if the port is immediately accessed and used?

PurposeTo compare complication rates in patients who have port-a-catheters inserted and left accessed for immediate use and those who have ports inserted but not accessed.MethodsIn this retrospecti...