cssi/SciSciGPT-SciSciNet huggingface dataset:
Convergence of cardiovascular and vestibular inputs on neurons in the medullary paramedian reticular formation

Abstract Extracellular recordings were made from 47 neurons in the caudal medullary paramedian reticular formation of chloralose-urethan anesthetized cats. The firing rate of all of these neurons was affected by stimulation of the contralateral vestibular nerve. The onset latency of the response to vestibular nerve stimulation was accurately determined for 43 of these neurons. The large majority (36 of 43) received short-latency (onset latency
On strained flames with hypergolic reactants: The H2/NO/F2 system in high-speed, supersonic and subsonic mixing-layer combustion

We report on a numerical investigation on the dynamics and structure of strained, non-premixed and premixed, H_2/NO/F_2 flames. This is an important, hypergolic reacting system that has been used in high- power chemical-laser systems and, presently, relied upon in experimental studies of high-speed, supersonic and subsonic, turbulent shear-layer mixing and combustion. The study included a detailed description of the chemical kinetics and molecular transport for the H_2 /NO/F_2 system and was conducted for a wide range of reactant concentrations and inert diluents, with flow/chemical parameters chosen to correspond to specific chemically reacting, supersonic mixing-layer experiments. Both non-premixed and premixed flames were studied using opposed-jet flow configurations. The results confirmed the experimental conclusion that, even at low reactant concentrations, the H_2/NO/F_2 system can sustain high Damkohler number chemical activity at high strain rates with room-temperature free streams. A comparison between the results of the present numerical simulations and the experimental chemically reacting mixing-layer studies, however, indicates that the predominant fraction of product formation in high-speed, turbulent, mixing layers must take place in a mode in which the reactants are in premixed, rather than in non-premixed, strained diffusion flames.
Models of Therapeutic Engagement Part II: Sincerity and Authenticity

Our topic concerns four relational modes of speaking and listening, and their relationship to truth and falsity. In a separate article, Part I introduced the topic and discussed the modes of diplomacy and integrity. The focus of Part II is on sincerity and authenticity, and on the interrelationship among all four modes and their differing functions in the totality of the clinical situation. Together the papers disentangle and address some of the technical issues that concern the relational group psychotherapist regarding topics of intersubjectivity, presentation of self, and self-disclosure. The four overlapping categories while nonexclusive are exhaustive; they supply conceptual references for the therapeutic stance one has adopted, allowing the therapist to be more aware of what he or she is doing and why.
Efficient characterization of the random eigenvalue problem in a polynomial chaos decomposition

A new procedure for characterizing the solution of the eigenvalue problem in the presence of uncertainty is presented. The eigenvalues and eigenvectors are described through their projections on the polynomial chaos basis. An efficient method for estimating the coefficients with respect to this basis is proposed. The method uses a Galerkin-based approach by orthogonalizing the residual in the eigenvalue–eigenvector equation to the subspace spanned by the basis functions used for approximation. In this way, the stochastic problem is framed as a system of deterministic non-linear algebraic equations. This system of equations is solved using a Newton–Raphson algorithm. Although the proposed approach is not based on statistical sampling, the efficiency of the proposed method can be significantly enhanced by initializing the non-linear iterative process with a small statistical sample synthesized through a Monte Carlo sampling scheme. The proposed method offers a number of advantages over existing methods based on statistical sampling. First, it provides an approximation to the complete probabilistic description of the eigensolution. Second, it reduces the computational overhead associated with solving the statistical eigenvalue problem. Finally, it circumvents the dependence of the statistical solution on the quality of the underlying random number generator. Copyright © 2007 John Wiley & Sons, Ltd.
Determining the phase-energy coupling coefficient in carrier-envelope phase measurements

For f-to-2f interferometers based on white-light generation in sapphire plates, the accuracy of the carrier-envelope (CE) phase measurement and stabilization is affected by the laser energy fluctuation. The coupling coefficient between the CE phase and the laser energy has been determined by modulating the pulse energy in an in-loop f-to-2f interferometer while measuring the CE phase variation with an out-loop interferometer. When the total spectral phase measured by the in-loop interferometer was locked, a 1% change in laser energy caused a 160 mrad shift in the CE phase of the output pulses.
Two-dimensional incompressible unsteady airfoil theory—An overview

Abstract Two-dimensional unsteady airfoil theory has a history that dates back at least 75 years. Closed-form solutions have been obtained for airfoil loads due to step response (either to a pitch input or to a gust), due to airfoil oscillations in the frequency domain, and due to generalized airfoil motions in the Laplace domain. It has also been shown that the response of airloads to airfoil motions can be formulated in state space in terms of ordinary differential equations that approximate the airfoil and flow field response. The more recent of these models are hierarchical in that the states represent inflow shape functions that form a convergent series in a Ritz–Galerkin sense. A comparison of the various approaches with each other and with alternative computational approaches yields insight into both the methodologies and the solutions.
Radiation induced osteochondroma in long-term survivors of childhood cancer☆

The records of 200 long term survivors of childhood cancer where reviewed. Radiation induced osteochondromata were detected in 12 patients (6%). Radiation had been administered in doses ranging from 1250 R (approximately 1500 rad) to 5500 rad between the ages of 8 months and 11 1/2 years. Radiation-induced osteochrondromata were detected 3 to 13 1/2 years later, with a median of 5 years. The osteochrondomata were single in 7 patients and multiple (2-4) in 5. Two occurred at sites of previous thoracotomy. Factors related to radiation induced osteochondromata are discussed.
Finite element analysis of 3-D braided composites

Abstract A numerical method, which utilizes the computer aided geometric modelling (CAGM) in conjunction with finite element procedures, is presented to prediict the mechanical behavior of 3-D braided composites. The CAGM, based on the computer geometric technique and textile formation process, provides the detailed information of the fiber architecture of 3-D braided composites. With the fiber architecture being defined, unit cell structures can be identified and be treated as space structures. Then, finite element procedures can be performed on each cell to obtain the elastic behavior of the composites. The present analysis includes the consideration of the interior and boundary elements of the entire cross-section, and consideration of bending moment of the yarns. The present model predicts a lower value of Young's modulus than that of experimental results. Modifications will be made on how to properly represent the matrix affect of a 3-D braided composite.
The solubility of the noble gases He, Ne, Ar, Kr, and Xe in water up to the critical point

The solubility of the noble gases Ar, He, Ne, Kr, and Xe in pure water was measured from 298 to 561°K. These data in turn were extrapolated to the critical point of water, thus providing a complete set of Henry's law constants from 274 to 647°K when combined with the existing literature data. Equations describing the behavior of the Henry's law constants over this temperature range are also given. The data do not confirm extrapolations of empirical correlations based on low-temperature solubility data.
Growth of S49 wild type cells in 3 nM epinephrine increases cyclic AMP phosphodiesterase activity.

Abstract In this communication we report that intact cell measurements of cAMP decay have shown an increase averaging over 80% in the cAMP decay constant (k dy ) in intact S49 WT cells following a 24 hour growth in 3 nM epinephrine (24 hr/3 nM epinephrine). A comparable percentage increase was seen in cell free PDE activities from cells similarly treated. The enhanced PDE activity and k dy acre detectable after 6 hours of incubation with 3 nM epinephrine, and were maximal by 24 hours of incubation. Lysate PDE activity returned to control levels within 24 hours after the cells were transferred to epinephrine-free growth medium. The increased PDE activity present in S49 WT cells after 24 hr/3 nM epinephrine was the result of increased concentrations of the enzymes already present or the expression of very similar enzymes, rather than the expression of enzymes with markedly different characteristics. Firstly, the apparent K m values for the PDE's in lysates from control and 24 hr/3 nM epinephrine cells were both in the region of 1 μM. Secondly, PDE activities in lysates from 24 hr/control and 24 hr/3 nM epinephrine S49 WT cells showed similar sensitivities to PDE inhibitors. There was support for the hypothesis that the increase in PDE activity in 24 hr/3 nM epinephrine S49 WT cells is dependent on the presence of cAPK. That is, although 24 hr/3nM epinephrine caused a distinct homologous desensitization of adenylate cyclase in S49 kin cells, neither k dy nor lysate PDE activity were affected. Additionally, 24 hours incubation of S49 WT cells with 3 μM dibutyryl cAMP resulted in increased PDE activity. Finally, the stimulatory effect of 24 hr/3 nM epinephrine on PDE activity was inhibited in the presence of cycloheximide, suggesting the involvement of protein synthesis in the process. This study shows that prolonged treatment with very low concentrations of epinephrine results in an increase in PDE activity which had a significant effect on cAMP accumulation. The increases were quantified by intact cell and cell free measurements, with kinetic data which were consistent with the hypothesis that the increased PDE activity in 24 hr/3 nM epinephrine cells reflected an increase PDE synthesis which was dependent on activation of the cAPK.
Adherence to Cancer Prevention Guidelines in 18 African Countries

Background Cancer rates in Africa are projected to double by 2030 due to aging and increased exposure to cancer risk factors, including modifiable risk factors. We assessed adherence to 5 modifiable cancer risk factors across 18 African countries. Methods Data on adults 18 years and older were obtained from the 2002–2004 World Health Survey. Adherence to current World Cancer Research Fund guidelines on smoking, alcohol, body weight, physical activity, and nutrition was assessed. Adherence scores ranged from 0 (no guideline met) to 5 (all guidelines met). Determinants of adherence were assessed using multivariable linear regression adjusted for individual and country level characteristics. Results Across all countries, adherence to the guidelines among adults was high for smoking (72%–99%) and alcohol (85%–100%), but low for body weight (1.8%–78%), physical activity (3.4%–84%) and nutrition (1.4%–61%). Overall adherence score ranged from 2.32 in Mali to 3.72 in Comoros. In multivariable models, residing in low versus high SES households was associated with reduced adherence by 0.24 and 0.21 points for men and women respectively after adjusting for age, gender, education, and marital status (p<0.001). Every % increase in GDP spent on health was associated with increased adherence by 0.03 in men and 0.09 in women (p<0.001). Conclusions The wide variation in adherence to cancer prevention guidelines observed across countries and between population sub-groups suggests the need for targeted public health efforts to improve behaviors related to body weight, physical activity and nutrition.
Bike Messengers and the Really Real: Effervescence, Reflexivity, and Postmodern Identity

Out of more than two thousand bike messengers in New York City, a few hundred participate in alleycats—illegal races held in open traffic. Surrounding this racing scene is a vibrant messenger community. Messengers who race in or attend alleycats carry their messenger identity into all aspects of their lives. Through direct participant observation, this article proposes that alleycats function as Durkheimian rituals for these messengers. Alleycats express the central values of the social world. Lost in collective effervescence, the individual confronts these values as objectified truths, which allow messengers to form stable identities. Further, bicycles, messenger bags, and other objects become sacred symbols within this ritualization process. The ability of messengers to construct such nonreflexive identities is juxtaposed with theories about the self in postmodernity. In The Meaning of Culture , Allan (1998) claims that reality construction is predicated on affect-meaning—the felt reality of culture. This stance comes from the application of Durkheim’s theory of the role of rituals in producing meaning. Although the ecstatic religious rituals that interested Durkheim may be less evident in our time, any number of secular rituals exist that are similarly essential for creating meaning. Rituals in the Durkheimian sense are not static and archaic ceremonies. According to Collins’s (2004) reading of Durkheim, a ritual is “a mechanism of mutually focused emotion and attention producing a momentarily shared reality” (p. 7). The present article focuses on one example of such a meaning-generating secular ritual among bicycle messengers—“alleycats,” or illegal races held in open traffic. While there are over two thousand messengers in New York City, only a few hundred participate in alleycats. Surrounding this racing scene is a vibrant messenger community. Bike messengers who race in or attend alleycats strongly identify with what can be conceptualized as a messenger lifestyle. That is to say, these individuals do not simply
An experimental examination of double marginalization and vertical relationships

Abstract The presence of a vertical externality, and therefore an incentive to integrate or to impose vertical restraints, is investigated in 11 posted-offer experiments. Upstream markets are characterized by a single seller. When the downstream market consists of three firms, there is no evidence of a vertical externality, and behavior is consistent with the vertically integrated outcome. With a single firm downstream, a vertical externality is present and the Nash prediction is supported. An analysis of individual market behavior reveals that firms approximate their best response functions, with some indication that they improve over time.
Time-resolved three-color coherent Raman scattering applied to polycrystalline and opaque solids

A new time-resolved coherent Raman technique (three-color picosecond coherent anti-Stokes Raman scattering), which uses a backscattering geometry and three colors obtained from three different lasers, is demonstrated. The advantage of this technique over conventional two-color picosecond coherent anti-Stokes Raman scattering is that it is insensitive to sample morphology. It is used to study time-dependent vibrational dephasing from opaque, polycrystalline solids at low temperature. A quantitative treatment of the limiting apparatus time response, where each pulse has a different duration and where there is arrival-time jitter between the pulses, is derived. New measurements of vibrational dynamics in low-temperature carbon disulfide indicate that polycrystalline samples are more homogeneous, on a microscopic level, than the large single crystals used in previous work. Raman line broadening in a sample of naphthalene in which strain is induced intentionally by grinding and compression is also investigated.
Hydrogen overpotential on rare earth metals

Abstract Hydrogen overpotential measurements have been performed on yttrium and 12 rare earth metals in phosphate buffered phosphoric acid. Tafel constants, β, and exchange current densities, i 0 , have been accurately determined by a graphical analysis technique. Correlations between electrochemical and physical properties are discussed.
Matrix Deposition Modulates the Viscoelastic Shear Properties of Hydrogel-Based Cartilage Grafts

Hydrogel-based scaffolds such as alginate have been extensively investigated for cartilage tissue engineering, largely due to their biocompatibility, ambient gelling conditions, and the ability to support chondrocyte phenotype. While it is well established that the viscoelastic response of articular cartilage is essential for articulation and load bearing, the time-dependent mechanical properties of hydrogel-based cartilage scaffolds have not been extensively studied. Therefore, the objective of this study was to characterize the intrinsic viscoelastic shear properties of chondrocyte-laden alginate scaffolds and determine the effects of seeding density and culturing time on these properties. Specifically, the viscoelastic properties (equilibrium and dynamic shear moduli and dynamic phase shift angle) of these engineered cartilage grafts were measured under torsional shear. In addition, the rapid ramp-step shear stress relaxation of the alginate-based cartilage scaffolds was modeled using the quasi-linear viscoelastic (QLV) theory. It was found that scaffold stiffness increased with both culturing time and cell density, whereas viscosity did not change significantly with cell density (30 vs. 60 million/mL). Similar to native cartilage, the energy dissipation of engineered scaffolds under pure shear is highly correlated to the glycosaminoglycan content. In contrast, collagen content was not strongly correlated to scaffold shear modulus, especially the instantaneous shear modulus predicted by the quasi-linear viscoelastic model. The findings of this study provide new insights into the structure-function relationship of engineered cartilage and design of functional grafts for cartilage repair.
Long-term influence of an initial exposure to alcohol on the rat hypothalamic-pituitary axis

Objective: We have previously shown that adult male rats injected with alcohol daily for 3 consecutive days displayed a significantly blunted ACTH to a second alcohol injection, given 3 to 7 days later. The purpose of the present work was to determine the maximum duration over which the ACTH response remained blunted after an initial alcohol treatment. Methods: Male rats were exposed to alcohol (intragastrically or via vapors for 4 hr) on three consecutive days, starting when they were 22 (group A), 34 (group B), or 50 days old (group C). Control animals were injected with the vehicle intragastrically or kept in chambers through which normal air was circulated. At 60 days of age, the animals were injected with the vehicle or alcohol (4.5 g/kg intragastrically) to determine whether the initial treatment had long-term consequences on the ACTH response to a second alcohol challenge. Results: Rats of group C, pretreated with alcohol via intragastric injections or vapors, all exhibited a blunted ACTH response to the second acute alcohol challenge. In contrast, the second alcohol challenge only attenuated ACTH responses in rats of group B that had received intragastric injections, but not vapors. Group A showed a comparable response to acute intragastric alcohol injection at 60 days of age regardless of whether they had been preexposed to the drug. This was not due to a lack of neuroendocrine response because alcohol vapors significantly increased plasma ACTH levels and up-regulated paraventricular nucleus neuronal activity regardless of the age at which it was initially administered. Conclusions: Repeated (daily for 3 consecutive days) administration of alcohol by the gastric route induces a long-lasting (up to 24 days) but not permanent blunting of the ACTH response to a second (acute) alcohol challenge. The fact that alcohol delivered by inhalation only caused a relatively brief (≤8 days) decrease in the ability of a second intragastric alcohol challenge to release ACTH suggests that the mode of alcohol delivery influences its long-term consequences.
In vitro inhibition of testosterone biosynthesis by ketoconazole.

Oral ketoconazole has been demonstrated to lower plasma testosterone in man. Measurement of blood precursors of testosterone suggest that ketoconazole may have its effect inhibiting the 17,20-desmolase enzyme within the testis. To substantiate this, a series of in vitro experiments was conducted using the rat testis to determine where in the testosterone biosynthetic pathway ketoconazole has its effect. To accomplish this, an assay system to measure 17α-hydroxylase, 17,20-desmolase, and 17β-hydroxysteroid dehydrogenase activities involved in the Δ4-testosterone biosynthetic pathway was developed. It was demonstrated from dose-response and time-course experiments that a dose of approximately 10 μg/ml ketoconazole was sufficient to inhibit in vitro testicular steroidogenesis. Using dosages between 10 and 300 μg/ml ketoconazole, a marked inhibition of both the 17α-hydroxylase and the 17,20-desmolase activities occurred. Ketoconazole under these conditions had no effect on 17β-hydroxysteroid dehydrogenase act...
Antigenic Properties of a Homogeneous Tobacco Mosaic Virus–Hapten Conjugate

Anti-hapten antibodies may only be induced if the hapten modifies the conformation of the protein carrier.
Laser-Induced Nonresonance Atomic Fluorescence in an Analytical Laser Microprobe Plume

Abstract Laser-induced nonresonance atomic fluorescence is used in conjunction with absorption and emission measurements to study the spatial and temporal distribution of atomic species in a laser microprobe plume. Microplumes were formed in helium, neon, and argon atmospheres at pressures from 50 to 500 Torr using stainless steel and niobium alloy samples. Studies of Fe, Ti, Zr, and Hf are reported. The signal-to-noise ratio for Fe is three times greater for Stokes direct-line fluorescence than for resonance detection. The major source of noise is in the fluorescence signal for both modes of detection. Spatial scans at different pressures indicate that atmospheric density strongly affects the interaction of the microplume with the atmosphere. At constant atmospheric pressure, inner filter effects are more severe in higher density gases. Optical saturation helps to reduce some of the prefilter effect. The laser microplume undergoes a rapid upward expansion from the sample and remains contiguous to the surface early in the lifetime of the microplume. Later in the lifetime, the microplume separates from the sample surface and eventually disperses into the atmosphere. The dispersal of the microplume occurs much faster in helium than in argon.
Assembly of the Sindbis virus spike protein complex.

Abstract The Sindbis virus glycoproteins E1 and E2 are organized into 80 trimers of heterodimers within the virus envelope. Using pulse–chase protocols and chemical crosslinkers, we have found that E1 and E2 precursor, PE2, rapidly assemble into heterodimers and then into trimers of heterodimers after translocation into the endoplasmic reticulum. E1 folds into its mature conformation within the endoplasmic reticulum via at least three intermediates differing in the configurations of their disulfide bonds. PE2 can pair with the second of these E1 folding intermediates. The remaining E1 folding steps, therefore, occur after E1–PE2 multimers begin to form. Quaternary interactions between E1 and PE2 may help guide the folding of E1. While no PE2 folding intermediates have yet been detected, we have found that PE2 transiently enters into large, noncovalent complexes or aggregates with other PE2 molecules and/or with unknown host factors prior to pairing with E1.
A note on the optimality conditions for the bilevel programming problem

A counterexample is given to demonstrate that previously proposed necessary conditions for the bilevel programming problem are not correct. An interpretation of the difficulty is given by appealing to a “theorem of alternative” result presented in the original work.
Caloric restricted male rats demonstrate fewer synapses in layer 2 of sensorimotor cortex

Previous studies have demonstrated an age-related decline in the density of presumptive inhibitory synapses in layer 2 of rat sensorimotor cortex [J. Comp. Neurol. 439(1) (2001) 65]. Caloric restriction has been shown to ameliorate age-related deterioration in a variety of systems and to extend life span. The present study tested the hypothesis that caloric restriction would prevent the previously reported age-related synaptic decline. Accordingly, synaptic density in layer 2 of sensorimotor cortex was compared between 29-month-old male rats fed ad libitum and 29-month-old male rats that were caloric restricted (60% of ad libitum calories) from 4 months of age. In serial electron micrographs, the physical disector was used to determine the numerical density of presumptive excitatory and inhibitory synapses (those containing round or nonround vesicles, respectively) as well as that of neurons. Not only was the previously reported age-related decline in numerical density of presumptive inhibitory synapses not ameliorated by caloric restriction, the numerical density was significantly lower in caloric restricted than in ad libitum fed rats for total as well as for presumptive excitatory and inhibitory synapses. Analysis further revealed no difference in the numerical density of neurons in this region. Relating synapse density to neuron density as the ratio of synapses to neuron also demonstrated significantly fewer synapses per neuron in caloric restricted than in ad libitum fed old rats. Finally, synapse length was significantly less in caloric restricted rats. These results suggest that not only does caloric restriction fail to prevent the age-related decline in presumptive inhibitory synapses, it results in fewer presumptive excitatory synapses as well.
Regulation of endothelial cell DNA synthesis and adherence.

A defined medium has been developed for primary culture of cells from human umbilical vein that will support maximal levels of cell division. The role of medium components in regulating the amount of thymidine incorporation has been assessed; insulin and to a lesser extent fibroblast growth factor (FGF) both increased the rate of incorporation when hydro-cortisone (HC) was present in the medium. Although these hormones in nonserum medium can stimulate incorporation, plating and maintenance of cells in serum medium for 12 h is necessary before transfer to defined medium. Without serum for this period, cells placed in defined medium, though well attached, did not divide. From the pulse: chase experiments it appears that more than one round of replication was supported by the 12-h period in serum.
Correlation for dropwise condensation heat transfer: Water, organic fluids, and inclination

Abstract Two generalized dropwise condensation heat transfer coefficient correlations (a heat flux dependent and a non-heat flux dependent) covering water and organic fluids are presented. The correlations accurately cover all fluids using two curve-fit parameters that are common to all fluids. The derived heat transfer coefficient correlations take the form of a power law expression. The generalized form of both correlations is derived by making several modifications to the Le Fevre and Rose model. Key additions to the Le Fevre and Rose model include the effect of contact angle on droplet height along with a complimentary method of estimating contact angle on well promoted surfaces. The final expression for the dropwise condensation Nusselt number re-emphasizes the view that dropwise condensation is a conduction heat transfer process limited primarily by the maximum departing droplet size, droplet height, and interfacial heat transfer coefficient. Using a data set which includes steam, propylene glycol, ethylene glycol and glycerol data, an error tolerance of ±15% is reported for 92% of the data and ±27% for all of the data using a non-heat flux dependent expression with common empirical coefficients. A heat flux dependent correlation is also presented which re-introduces a term that is neglected in the derivation of the non-heat flux dependent correlation. However, due to ambiguities between data acquired for water and especially some of the lower surface tension organic fluids, the heat flux dependent correlation is only recommended for water. Both models also match reasonably well with data acquired on inclined surfaces when a straight forward correction is made to the gravitational force acting on departing droplets. A comment is also included on the effect of the promoter thermal resistance on dropwise condensation in light of recent theoretical and experimental results regarding the thermal resistance of promoter/water interfaces.
Complexity and evolution: What everybody knows

The consensus among evolutionists seems to be (and has been for at least a century) that the morphological complexity of organisms increases in evolution, although almost no empirical evidence for such a trend exists. Most studies of complexity have been theoretical, and the few empirical studies have not, with the exception of certain recent ones, been especially rigorous; reviews are presented of both the theoretical and empirical literature. The paucity of evidence raises the question of what sustains the consensus, and a number of suggestions are offered, including the possibility that certain cultural and/or perceptual biases are at work. In addition, a shift in emphasis from theoretical to empirical inquiry is recommended for the study of complexity, and guidelines for future empirical studies are proposed.
English Language Learners' Perceptions of School Environment

Abstract The number of students who speak languages other than English continues to grow in both rural and urban public schools in the United States. This study investigated the perceptions of 123 students (57 monolingual and 66 English language learners [ELLs]) from a rural public elementary school in North Carolina with respect to school climate, curriculum and instruction, extracurricular activities, self-efficacy, and self-esteem. All of these indicators contribute to an overall perception of schools and affect learning experiences of monolingual students and ELLs. Results indicate that the perceptions of monolingual learners and ELLs in this particular elementary school are similar.
Learning to ask relevant questions

Abstract This paper describes an effective technique for relevant questioning in expert systems whose knowledge base is encoded in a propositional formula in conjunctive normal form. The methodology does not require initial knowledge about the relationships between questions. Instead, the system learns such relationships over time as follows. After each session, the system analyzes its questioning, deduces how it could have obtained each conclusion without asking irrelevant questions, and records the relevant questions and answers in so-called processed dialogues. When a question is to be selected in a subsequent session, the system measures the relevancy of questions using the processed dialogues, ranks the questions according to that measure, and asks the highest-ranked question next. We have used the methodology in an expert system that handles industrial chemical exposure management. In that application, the system learned rather quickly to ask relevant questions and became just as effective as a human expert.
Classroom Age Composition and Vocabulary Development Among At-Risk Preschoolers

Research Findings: The purpose of this exploratory study was to examine the relationship between classroom age composition and preschoolers’ vocabulary gains over an academic year and also to examine whether these relations were moderated by classroom quality. In this study (N = 130 children in 16 classrooms representing a subset of all children enrolled in these classrooms), results showed a significant cross-level interaction between classroom age composition and children's age, suggesting positive effects of greater variance in classroom age composition for younger but not older children. The interaction between behavior management (1 dimension of classroom quality) and classroom age composition was also significant, indicating that a wider distribution of classroom age composition was positively related to children's vocabulary gains within classrooms characterized by better behavior management. Practice or Policy: Findings underscore the importance of children's social interactions with more knowledg...
Observations on abortive infection of Micrococcus lysodeikticus with bacteriophage.

Abstract Screening of ultraviolet irradiated Micrococcus lysodeikticus cultures for phage-resistant mutants yielded strains capable of producing plaques with virulent phage N6 but not with serologically related virulent phage N1. Adsorption tests conducted with a representative strain revealed that the culture was not truly resistant to N1 since this phage was efficiently adsorbed. Adsorption initiated an abortive infection which terminated with complete lysis of the host cells without liberation of infectious phage. An apparent reversal of the abortive infection was observed when the mutant cells were infected simultaneously with both phages. Under such conditions, 50–60% of the infected cells produced infectious phage, and single cell burst experiments showed that nearly every productive cell yielded both parental phage types and two new stable types in which the plaque morphology and host range characteristics were recombined. It was found that the percentage recovery of infectious centers from mixed-infected cells was influenced by the order in which the two phages infected the cells, and by the time interval between infection with the first phage and subsequent infection with the second phage. When cells were infected first with N6, delay of infection with N1 resulted in increased recoveries. When cells were infected first with N1, recoveries fell off at a rate which was exponential with respect to the time of delay in adding N6. During the course of the abortive infection, there was no increase in rate of oxygen uptake and no net synthesis of ribonucleic acid. Deoxyribonucleic acid was synthesized at a considerably higher rate, and the amount produced was two to three times greater than that found with any of the productive infections studied.
Clinical and Hematologic Benefits of Partial Splenectomy for Congenital Hemolytic Anemias in Children

Congenital hemolytic anemias frequently lead to severe hemolysis due to splenic sequestration of abnormal erythrocytes. 1 For children with hereditary spherocytosis (HS), a total splenectomy eliminates the main source of erythrocyte destruction. For children with other hemolytic anemias, a splenectomy eliminates splenic sequestration and reduces symptoms of hypersplenism. The use of total splenectomy in children is restricted by concern of overwhelming postsplenectomy sepsis. 2–5 In children less than 5 years of age, the risk of overwhelming postsplenectomy sepsis may be increased 60- to 100-fold compared to children who have not had a splenectomy. 4 Although the risk of overwhelming postsplenectomy sepsis is reduced by use of immunizations to Streptococcus pneumoniae, Meningococcus, and Haemophilus influenzae as well as postoperative antibiotic prophylaxis, its risk is never eliminated. 5 Moreover, concerns persist of incomplete protection by pneumococcal vaccinations, antibiotic resistance, and poor compliance with antibiotic prophylaxis. 5,6 For children with congenital hemolytic anemias, a partial splenectomy has been proposed as an alternative to total splenectomy, with the goal of removing enough spleen to gain a desired hematologic effect while preserving splenic immune function. 7–10 However, the use of partial splenectomy is limited because of technical difficulties and concerns of splenic regrowth. 7,8,11,12 Recently several groups have renewed an interest in partial splenectomy. 7–10 To assess the role of partial splenectomy in symptomatic children with various congenital hemolytic anemias, we have followed 25 children with various congenital hemolytic anemias who underwent partial splenectomy. We examined the effects of partial splenectomy on hemolysis, splenic phagocytic and immune function, and splenic regrowth. Our results suggest that partial splenectomy may be beneficial for a variety of congenital hemolytic anemias.
X-ray absorption study of tantalum oxide films on silicon

Abstract The results of X-ray absorption measurements are used to demonstrate that non-crystalline Ta0.29O0.71 films, prepared by thermal oxidation of deposited Ta on Si single crystals, are glassy in the sense that the short range order and bond (chemical) ordering closely resemble those in β-Ta2O5.
The value and limitation of radionuclide angiocardiography with stress in women.

The radionuclide angiograms (RNA) with exercise of 64 females were reviewed. There were 30 patients with coronary artery disease, 5 normal controls, 6 patients with normal coronary arteries and hemodynamics, and 23 patients with cardiomyopathy (left ventricular end-diastolic pressure ⩾15 or ⩾18 pre- and postangiogram). In the coronary artery disease group, 12 of the 30 (40%) had ST-segment depression and another 12 (40%) had a wall motion abnormality with exercise. In the cardiomyopathy group, 8 of the 23 (35%) had ST-segment depression, and (26%) developed wall motion abnormality with exercise. In the normal coronary group, 2 of the 6 (33%) had a positive ST-segment response, and none had a wall motion abnormality with exercise. The ejection fraction (EF) response with exercise in the normal coronary group was 65.4-72% (p 0 was a normal response, then the specificity was 10 of 11 (91%) for normals or 5 of 6 (83%) for the normal coronary group at angiography. The sensitivity for coronary artery disease was 23 of 30 (77%) and 17 of 23 (74%) for cardiomyopathy. Of the cardiomyopathy patients 3 of 4 (75%) had a positive TL-201 scan with exercise consistent with reversible ischemia. In summary, many females with chest pain have abnormal hemodynamics despite normal coronary arteries. Use of °EF>0 as the criteria for a normal response to exercise is more specific than °EF⩾5 with exercise for separating normals from abnormals. A wall motion abnormality that develops with exercise can be seen with cardiomyopathy or with coronary artery disease in females. The radionuclide angiographic studies with exercise can separate normal from abnormal, but not cardiomyopathy from coronary artery disease. The positive TL-201 response with exercise in the cardiomyopathy group would suggest that a regional process could be present and only cardiac catheterization can separate cardiomyopathy from coronary artery disease.
Review of WETS–The Workshop on Extra-Tropical SST anomalies

WETS—the Workshop on Extra-Tropical SST anomalies—was convened to review our present understanding of how the middle- and high-latitude ocean interacts with the atmosphere. Here, the author discusses some of the new information and results presented at the workshop and briefly describes some promising directions for further research.
Models of Geriatrics Practice: Post‐Hospital Sub‐Acute Care: An Example of a Managed Care Model

OBJECTIVE: This article describes Transitional Care Centers (TCC), an innovative sub-acute care program developed by a large managed care organization (HealthPartners in Minnesota) in partnership with five area nursing homes. The purpose of the TCC is to promote continuity of care for frail older members covered under a TEFRA risk contract. DESIGN: This is a retrospective study of the experiences and outcomes of enrollees who received TCC compared with a like group of enrollees who received customary continuity care through contract services. SETTING: The TCCs are established contractually in five area nursing homes; these facilities keep at least 15 beds available to the health plan for round-the-clock, 7 days per week admissions for sub-acute care. Designated staff from these facilities and designated geriatric nurse practitioners and geriatricians from HealthPartners follow established targeting, admissions, assessment, care planning, and discharge planning procedures to provide team care for these patients at the facilities. PARTICIPANTS: The TCC program is targeted to patients requiring rehabilitation therapy (post-cardiovascular accident, post-fracture/replacement) who are deconditioned, or those with uncomplicated infections (urinary tract infection, pneumonia). A total of 1144 patients participated in the TCC program in the 1-year program under report, and 253 were surveyed in regard to their experience. One hundred Health-Partners physicians were surveyed about the program. RESULTS: Post-acute length of stay in the TCC was substantially lower than that in customary care settings in contract nursing homes (14.3 versus 20.5 days). Rehospitalization rates from these units were comparable to or better than those from other sub-acute units. Patient and primary care physician satisfaction with the units was high. The program provided economic benefit to both partners. The health plan's negotiated rate for the TCC units was 38% less than that paid in noncontractual facilities. CONCLUSION: The TCC partnership provides rehabilitative and geriatric evaluation services in settings more conducive to and less costly than such care usually, and yields improvements in care and utilization outcomes.
Optimal tradeoffs for addition on systolic arrays

The complexity of adding twon-bit numbers on a two-dimensional systolic array is investigated. We consider different constraints on the systolic array, including:whether or not the input and output ports lie on the periphery of the array,constraints placed on the arrival and departure times of inputs and outputs. For all combinations of the above constraints, we obtain optimal tradeoffs among the resources of area, pipeline delay, and worst-case time. It turns out that there is a subtle interplay among the constraints and some of our results seem counterintuitive. For instance, we show that allowing more-significant bits to arrive earlier than less-significant bits can speed up addition by a factor of logn. We also show that multiplexing can often result in a smaller array. On the other hand, we show that some known results, such as Chazelle and Monier's bounds for arrays that have input/output ports on the perimeter, also hold in less constrained models.
Post processing with first- and second-order hidden Markov models

In this paper, we present the implementation and evaluation of first order and second order Hidden Markov Models to identify and correct OCR errors in the post processing of books. Our experiments show that the first order model approximately corrects 10% of the errors with 100% precision, while the second order model corrects a higher percentage of errors with much lower precision.
Phorbol diesters and transferrin modulate lymphoblastoid cell transferrin receptor expression by two different mechanisms.

Expression of transferrin receptors (TfR) by activated lymphocytes is necessary for lymphocyte DNA synthesis and proliferation. Regulation of TfR expression, therefore, is a mechanism by which the lymphocyte's proliferative potential may be directed and controlled. The authors studied mechanisms by which lymphoblastoid cells modulate TfR expression during treatment with phorbol diesters or iron transferrin (FeTf), agents which cause downregulation of cell surface TfR. Phorbol diester-induced TfR downregulation occurred rapidly, being detectable at 2 min and reaching maximal decreases of 50% by 15 min. It was inhibited by cold but not by agents that destabilize cytoskeletal elements. Furthermore, this downregulation was reversed rapidly by washing or by treatment with the membrane interactive agent, chlorpromazine. In contrast, FeTf-induced TfR downregulation occurred slowly. Decreased expression of TfR was detectable only after 15 min and maximal downregulation was achieved after 60 min. Although FeTf-induced downregulation also was inhibited by cold, it was inhibited in addition by a group of microtubule destabilizing agents (colchicine, vinblastine, podophyllotoxin) or cytochalasin B, a microfilament inhibitor. Furthermore, FeTf-induced downregulation was not reversed readily by washing or by treatment with chlorpromazine. Phorbol diesters cause TfR downregulation by a cytoskeleton-independent mechanism. These data indicate that TfR expression is regulated by twomore » independent mechanisms in lymphoblastoid cells, and they provide the possibility that downregulation of TfR by different mechanisms may result in different effects in these cells.« less
When Film Critics Agree: Does Film Genre Matter?

This article reports the results of an analysis of patterns of “agreements” and “disagreements” among 45 professional critics' ratings of over 1300 films. These ratings—awarded along a scale from 0...
Is Investor Purchasing of Foreclosures Related to Neighborhood Crime? Evidence From a Phoenix Suburb

Little is known about how investors purchasing foreclosures during the recent U.S. housing crisis are affecting neighborhood crime. While they may decrease crime by reducing vacancies or bettering neighborhood conditions, they may increase it by escalating neighborhood turnover. Combining local police department data on calls for service with foreclosure, home sales, and sociodemographic data, this research uses longitudinal modeling to assess the relation between the purchasing of foreclosures by investors and calls for service in neighborhoods in Chandler, Arizona, a Phoenix suburb where investors are renting former foreclosures. Neighborhoods where foreclosures were more often purchased by investors had more calls for service about violent crime the following year.
Vertebroplasty, cognitive dissonance, and evidence-based medicine: what do we do when the 'evidence' says we are wrong?

Two recent trials call into question the efficacy of vertebroplasty for treating osteoporotic vertebral compression fractures and are leading many of us to question our assumptions about vertebroplasty.
Dysproteinemia, proteinuria, and glomerulonephritis

CASE PRESENTATION A 57-year-old woman was referred for evaluation of new-onset hypertension and proteinuria. The patient had developed lower extremity edema 3 months prior and had been treated with diuretics. Past medical history was significant for microscopic hematuria of many years’ duration thought secondary to nephrolithiasis, longstanding arthritis of the hands and hips, depression, and deep venous thrombosis that occurred following
Trade-affected workers: Manufacturing and services compared

Abstract In this study a combination of input-output and probit analysis is used to identify the demographic characteristics of services and manufacturing workers whose employment status is most likely to be favorably or unfavorably affected by a hypothetical change in net exports. The main finding is that while favorably affected manufacturing workers tend to be human-capital intensive the reverse is true for service workers. This finding conflicts with the extended Heckscher-Ohlin-Samuelson model of international trade which explains trade patterns by variations in factor endowments—including human capital—among regions.