cssi/SciSciGPT-SciSciNet huggingface dataset:
Leontief models, Markov chains, substochastic matrices, and positive solutions of matrix equations

Abstract Many applications of linear algebra call for determining solutions of systems of linear equations with certain prescribed properties. The Leontief input-output models in economics, for example, requires a solution vector all of whose components are nonnegative. The location of an equilibrium distribution for a regular Markov process involves finding a vector each of whose entries is positive. This paper presents an elementary constructive algebraic proof for finding such solutions and for discovering conditions under which they exist. The results extend the theory of solutions to such systems to matrix equations over arbitrary, not necessarily complete, ordered fields.
Strength of Cosmic Radio Sources

THE discovery of quasi-stellar objects has brought with it the realization that bremsstrahlung radiation in the radio wave region as generated in a plasma has not been properly understood. The present communication represents an effort to account for the unusually high levels of radio emission from quasars and to explain, in particular, the spectral output from the sub-structures A and B of 3C-273.
Three-temperature theory of gaseous ion transport

Abstract A three-temperature kinetic theory of gaseous ion transport through neutral atomic gases, valid for electric fields of arbitrary strength without restriction on the ion—atom mass ratio or interaction potential, is presented. The theory is based on the use of a set of basis functions in which the ions are allowed to have different temperatures parallel and perpendicular to the field, neither of which is necessarily equal to the gas temperature, and for which the ion velocity distribution function is displaced from the origin. Although the theory is more difficult to use than is the two-temperature theory of Viehland and Mason and of Burnett, it has the important advantage of yielding accurate results in low orders of approximation to quantities that are intrinsically anisotropic, notably ion diffusion coefficients.
Using molecular markers for detecting domestication, improvement, and adaptation genes

Development of statistical tests to detect selection (strictly speaking, departures from the neutral equilibrium model) has been an active area of research in population genetics over the last 15 years. With the advent of dense genome sequencing of many domesticated crops, some of this machinery (which heretofore has been largely restricted to human genetics and evolutionary biology) is starting to be applied in the search for genes under recent selection in crop species. We review the population genetics of signatures of selection and formal tests of selection, with discussions as to how these apply in the search for domestication and improvement genes in crops and for adaptation genes in their wild relatives. Plant domestication has specific features, such as complex demography, selfing, and selection of alleles starting at intermediate frequencies, that compromise many of the standard tests, and hence the full power of tests for selection has yet to be realized.
On point-halfspace graphs

The following definition is motivated by the study of circle orders and their connections to graphs. A graphs G is called a point-halfspace graph (in Rk) provided one can assign to each vertex v ϵ (G) a point pvRk and to each edge e ϵ E(G) a closed halfspace He ϵ Rk so that v is incident with e if and only if pv ϵ He. Let Hk denote the set of point-halfspace graphs (in Rk). We give complete forbidden subgraph and structural characterizations of the classes Hk for every k. Surprisingly, these classes are closed under taking minors and we give forbidden minor characterizations as well. © 1996 John Wiley & Sons, Inc.
Perioperative cardiovascular morbidity in patients with coronary artery disease undergoing vascular surgery after percutaneous transluminal coronary angioplasty.

Abstract Objective: Patients with coronary artery disease (CAD) who undergo noncardiac surgery are at increased risk for perioperative myocardial infarction (PMI). Undergoing successful coronary artery bypass grafting (CABG) before such surgery has been shown to decrease perioperative cardiac morbidity and mortality. Percutaneous transluminal coronary angioplasty (PTCA) is an alternative treatment for these patients. Perioperative cardiac morbidity in patients with CAD who underwent PTCA before their vascular surgery was reviewed. Setting: A tertiary care referral center for patients with cardiovascular heart disease. Participants: Review of vascular surgery database for patients who underwent vascular surgery preceded by PTCA between 1984 and 1995. Patients were excluded if they had a history of CABG within 2 years of surgery, had PTCA more than 18 months before surgery, or had incomplete data. Measurements: Data were collected concerning cardiac history, left ventricular (LV) function, perioperative cardiac morbidity (angina, MI, congestive heart failure [CHF], and arrhythmias). Main Results: Of 194 patients who underwent aortic abdominal surgery, carotid endarterectomy (CEA), or peripheral vascular surgery preceded by PTCA, 104 (54%) had a previous MI. Twenty-six patients (13.4%) had perioperative cardiac morbidity. Only one patient had an MI (0.5%; 95% confidence interval [CI], 0.0 to 2.8), whereas one patient died of CHF followed by multisystem organ failure (0.5%). The median interval between PTCA and surgery was 11 days (interquartile range, [IQR] 3 to 49 days). Patients who developed perioperative cardiac morbidity were older than those who did not (p = 0.02). Patients who had a history of CABG (before PTCA) had a higher incidence of postoperative angina (p = 0.04). The degree of preoperative LV dysfunction was linearly related to the incidence of new postoperative CHF (p = 0.01). Arrhythmias were more common in patients undergoing abdominal vascular surgery (17.9%) than in those undergoing CEA (2.5%; p = 0.03) or peripheral vascular surgery (5.2%; p = 0.02). Conclusion: High-risk cardiac patients undergoing vascular surgery who have had PTCA performed up to 18 months preoperatively have a low incidence of perioperative cardiac morbidity. Prophylactic PTCA may be beneficial in patients with CAD who are at high risk for perioperative cardiac complications.
Epistemic and Dialectical Regress

Dialectical egalitarianism holds that every asserted proposition requires defence when challenged by an interlocutor. This view apparently generates a vicious ‘regress of justifications’, since an interlocutor can challenge the premises through which a speaker defends her original assertion, and so on ad infinitum. To halt the regress, dialectical foundationalists such as Adler, Brandom, Leite, and Williams propose that some propositions require no defence in the light of mere requests for justification. I argue that the putative regress is not worrisome and that egalitarianism can handle it quite satisfactorily. I also defend a positive view that combines an anti-foundationalist conception of dialectical interaction with a foundationalist conception of epistemic justification.
MSL: a synthesis enabled language for distributed implementations

This paper demonstrates how ideas from generative programming and software synthesis can help support the development of bulk-synchronous distributed memory kernels. These ideas are realized in a new language called MSL, a C-like language that combines synthesis features with high level notations for array manipulation and bulk-synchronous parallelism to simplify the semantic analysis required for synthesis. The paper shows that by leveraging these high level notations, it is possible to scale the synthesis and automated bug-finding technologies that underlie MSL to realistic computational kernels. Specifically, we demonstrate the methodology through case studies implementing non-trivial distributed kernels -- both regular and irregular -- from the NAS parallel benchmarks. We show that our approach can automatically infer many challenging details from these benchmarks and can enable high level implementation ideas to be reused between similar kernels. We also demonstrate that these high level notations map easily to low level C code and show that the performance of this generated code matches that of handwritten Fortran.
The Sodium‐Calcium Ion Membrane Exchanger: Physiologic Significance and Pharmacologic Implications

The Na + -Ca 2+ exchanger is a non-ATP-dependent protein that, under steady-state conditions, extrudes Ca 2+ from the interior of the cell into the extracellular space via facilitated transport. The activity of the exchanger seems to be reduced in myocardial ischemia, leading to increased intracellular ca 2+ in the ischemic heart, which can result in arrhythmia, myocardial stunning, and necrosis. In contrast, congestive heart failure and myocardial hypertrophy are associated with increased exchanger activity and a decreased inotropic state. Pharmacologic agents are being developed to modulate sodium ion levels in the cell, which could enhance or reduce sodium-calcium exchange as needed in various pathophysiologic states. At this time there are no available drugs that act specifically on the Na + -Ca 2+ exchanger itself. The exchanger has been cloned, and inhibitory peptides of the exchanger may soon be available for possible use in treatment of congestive heart failure.
Explanation in apraxia with consequences for the concept of apraxia of speech

In this paper I would like to propose that under certain interpretations there are additional forms of “apraxia of speech” which differ from the frontal speech apraxias. I would like to propose further that certain phonological functions as understood by linguists are “epiphenomena” and operate in parallel with the hierarchically organized sensory-motor practic functions of the brain. The phonological functions involve selecting and sequencing of phoneme-like units which speakers believe themselves to be uttering. In actuality, they are uttering sounds, or “phones,” which may then be viewed as being produced by nervous firings giving rise to complex and synchronous muscular contractions resulting in acoustic impingements on the air. Practic brain function is involved at the neurological level throughout the whole process from ideation (potential) to production (kinetic). However, these processes must be worded carefully so as not to imply that phonemes are articulated. The nature of the phoneme is such that it cannot be uttered. It is a “psychologically real”
Using Change in the National Institutes of Health Stroke Scale to Measure Treatment Effect in Acute Stroke Trials

Background and Purpose— Outcome measures in acute stroke trials are being refined. Changes in neurological deficits might be useful outcome measures because they can measure the entire spectrum of deficits. Methods— We analyzed data from the acute stroke treatment trial Trial of Org 10172 in Acute Stroke Treatment (TOAST). Using logistic regression analysis, we modeled the probability of the TOAST predefined very favorable outcome (VFO; both Glasgow Outcome Scale 1 and modified Barthel Index 19 to 20) at 3 months. Within-subject changes (baseline−3 months) on the National Institutes of Health Stroke Scale (NIHSS) was the main predictor of interest. Results— The baseline median NIHSS for the entire TOAST cohort was 7, and it improved by 4 points (interquartile range 3 to 6) among 603 patient with VFO and by 2 points (interquartile range −1 to 5) among 638 patients without a VFO (P<0.001). The odds for VFO increased by 2.29 (95% CI, 2.06 to 2.54; P<0.001) for each 1-point improvement on the NIHSS. In receiv...
Perspective on Free-Energy Perturbation Calculations for Chemical Equilibria

Abstract An overview is provided on the computation of free energy changes in solution using perturbation theory, overlap sampling, and related approximate methods. As a specific application, extensive results are provided for free energies of hydration of substituted benzenes using the OPLS-AA force field in explicit TIP4P water. For a similar amount of computer time, the double-wide sampling and overlap sampling methods yield very similar results in the free-energy perturbation calculations. With standard protocols, the average statistical uncertainty in computed differences in free energies of hydration is 0.1 - 0.2 kcal/mol. Application of the power-series expansion in the Peierls equation was also tested. Use of the first-order term is generally reliable, while inclusion of the slowly-convergent, second-order fluctuation term causes deterioration in the results for strongly hydrogen-bonded solutes.
Cellular cholesterol stimulates acute uptake of palmitate by redistribution of fatty acid translocase in type II pneumocytes.

Cholesterol is an abundant lipid of lung surfactant, where its concentration changes relative to phospholipids in response to certain physiological conditions. We investigated the effect of the cellular cholesterol content on uptake and esterification of palmitic acid, and on cellular distribution of fatty acid translocase (FAT/CD36) in alveolar type II cells. Incubation of type II cells with methyl-β-cyclodextrin−cholesterol complexes increased the cholesterol content of lamellar bodies. The palmitate uptake of type II cells increased in parallel with the cellular cholesterol content. The content of FAT/CD36 increased in membranes and decreased in cytosol in type II cells. The detergent-insoluble fraction (DIGs), isolated from type II cells, was enriched in FAT/CD36 and caveolin-1 after increasing the cellular cholesterol. The total incorporation of labeled palmitic acid into glycerolipids and cholesterol ester (CE) increased by a factor of about 10 when the amount of unbound 14C-palmitic acid added to t...
Long-Time Tails and the Large-Eddy Behavior of a Randomly Stirred Fluid

The long-wavelength and low-frequency behavior of an incompressible, randomly stirred fluid is determined in $d$ dimensions by renormalization-group arguments. A free-field fixed point, which describes conventional hydrodynamics, is stable for $dg~2$ although we find nontrivial corrections to the leading behavior. These corrections give rise to long-time tails in a fluid near thermal equilibrium. A nontrivial fixed point controls the behavior for $dl2$, which is determined to all orders in $\ensuremath{\epsilon}=2\ensuremath{-}d$.
Limitations of indirect methods of estimating small bowel transit in man.

Experiments were carried out in healthy volunteers to explore the utility of a new [14C]lactulose breath test for measuring small intestinal transit time in man and to use this procedure to test whether two antidiarrheal agents, codeine and clonidine, alter small intestinal transit time during digestion of a liquid meal. In an initial validation study performed in 12 subjects (three studies in each subject), a liquid test meal containing 10 g [14C]lactulose was administered and the colonic entry time estimated from the time course of14CO2 excretion in breath compared with that of H2 excretion. There was a fair correlation (r=0.77;P<0.001) between results obtained by the two methods; both methods gave similar results, but14CO2 output was delayed when compared to H2 output and was incomplete. The meal also contained xylose and [13C]glycine, permitting the duodenal entry time of the meal to be estimated by the appearance of xylose in blood and13CO2 in breath, respectively. The same liquid meal was then used to examine the effect on small intestinal transit time (colonic entry time minus duodenal entry time) of codeine or clonidine.99Tc-sulphur colloid was also added to the meal to permit a comparison of small intestinal transit estimated by imaging with that estimated by the14CO2-lactulose breath test.99Tc radioactivity appeared in the cecum (as assessed using gamma scintigraphy) about 2 hr before14CO2 radioactivity appeared in breath; the correlation between transit time estimated by the two methods was moderate (r=0.61;P<0.05). Based on the [14C]lactulose data, small intestinal transit time ranged from<1 to 3 hr for a liquid meal containing 10 g lactulose; within-subject variation (coefficient of variation 17%) was considerably less than between-subject variation (coefficient of variation 56%). Codeine increased the small intestinal transit time significantly (from 2.7±0.3 hr to 5.0 ±0.9 hr; mean±SE), whereas clonidine did not alter small intestinal transit time, as estimated by the colonic entry time minus duodenal entry time. Neither drug influenced duodenal entry time. These results suggest that the [14C]lactulose breath test, which has only moderate accuracy, may have occasional utility as a convenient, noninvasive method for estimating small intestinal transit time in man. However, this study also suggests that indirect methods of estimating small bowel transit in man have limitations, variability, and possibly may lack the desired sensitivity.
Optimization of electrostatic energy harvesting device for wireless sensors application

In this paper, we put forward a coupled electromechanical model with differential equation arrays for an electret-based energy harvester with out-of-the plane gap closing scheme. The model is numerically solved for output voltage and displacement of the moveable electrode with given parameters by Matlab/Simulink software. Furthermore, system optimization is carried out using the coupled model to find the optimal values for the load resistance and the initial air gap to maximize the output power. For instance, at an external load resistance of 1 GΩ, a power output of 67 µW is achieved with the initial gap of 380 µm. This output power is promising for the potential applications on the wireless sensor networks and the internet of things.
A Primer on Tables and Figures

Tables and figures arc an integral part of the medium of communication of science and technology. An analysis of tables and figures, relying heavily on Euclidean terms (point, line and plane) explains something of their power–their ability to display with clarity large amounts of data, complex data relationships, and intricate three-dimensional configurations. Analysis also clarifies the mutual dependence of tables and figures and their accompanying texts. Additionally, analysis makes clear the semantic gap between tables and graphs, on the one hand, and illustrations, on the other. All are equally vital strategies in scientific and technical discourse. However, tables and graphs are paralinguistic extensions of scientific and technical dialects; illustrations, on the other hand, are a nonlinguistic supplement to these dialects. Finally, analysis provides clues for the teaching of proper graphic choice, good graphic ‘grammar,’ and the appropriate contextualization of graphs.
Active fiber composites for structural health monitoring

An embedded active fiber composite tape was investigated for use as a sensor for structural health monitoring. The material has unidirectional piezoceramic fibers with interdigital electrodes on the top and bottom surfaces and is poled in the fiber direction. A long active fiber composite tape with segmented electrodes was modeled as a sensor to measure longitudinal stress waves in a uniform cantilever bar. Only plane longitudinal standing and traveling waves in the bar are modeled. The sensor was connected to an electrical tuning circuit to filter out undesirable noise due to ambient vibrations. The elastic response of the bar was compute in closed form at small time steps, and the coupled piezoceramic constitutive equations and the electrical circuit equations were solved by numerical integration using the Newmark-Beta method. Strain vibration and wave propagation responses were computed in the simulations. The simulations indicate that such a sensor will be capable of detecting damage to the bar from the change sin the wave propagation responses. Further, the sensor has adequate sensitivity to detect fiber breaks in the composite bar. An active fiber composite patch was also tested to measure vibration and simulated acoustic emissions.
A heterogeneous kinetic model for the cutinase-catalyzed hydrolysis of cyclo-tris-ethylene terephthalate.

The kinetics of enzyme-catalyzed hydrolysis of the polyester oligomer cyclo-tris-ethylene terephthalate, commonly known as cyclic trimer, using a developmental cutinase is reported. The effect of substrate surface area and enzyme concentration, in a largely aqueous medium, on the rate of hydrolysis was measured via spectrophotometric measurement using high performance liquid chromatography (λ 254 nm) at 60 °C in a glycine buffer (pH 8). The rate was strongly dependent on the substrateapos;s surface characteristics. When the substrate surface area was relatively small and the substrate was relatively low in crystallinity, the reaction followed zero order kinetics, whereas a first order rate constant was obtained when the substrate surface area was increased considerably and the crystallinity was relatively high.
Binding, Phases, and Locality

. The central issue addressed here is syntactic locality, and the main proposal is that movement and anaphoric relations are governed by a unified concept of locality. The specific phenomena to be investigated are (i) infinitive constructions, in particular, Accusativus cum Infinitivo (AcI) complements, (ii) the German Possessor Dative Construction (PDC), with a dative nominal playing the role of both possessor and affectee, and (iii) binding, the conditions under which reflexive and nonreflexive pronouns may occur. The focus is mainly on binding and how to account for instances of noncomplementarity, but also on the PDC, which can be analyzed as possessor raising. Ultimately, it will become clear that the unifying principle of locality must be the phase, and that phasehood determines the transparency/opacity of phrases (CP, vP, DP, and PP) for both movement and anaphoric relations.
Hyperaccountability: Economic voting in Central and Eastern Europe

Abstract Are citizens in the new democracies of Central and Eastern Europe able to hold politicians accountable at elections? The inheritance of communism—disengaged citizens, economic flux, and inchoate party systems—might be expected to weaken accountability. Looking at the results of 34 elections in 10 Central and Eastern European countries, this paper finds instead a phenomenon that it calls hyperaccountability. Incumbents are held accountable for economic performance—particularly for unemployment—but this accountability distinguishes not between vote losses and gains, but between large and small losses. This result is significant in several respects. The evidence for economic voting restores some faith in the ability of voters to control their representatives in new democracies. The consistency of punishment in the region, however, may mitigate some of the benefits of economic voting. If incumbents know they will lose, then they may decide to enrich themselves when in power rather than produce good policies.
How much change in the case mix index is DRG creep

Abstract We re-abstracted a nationally representative sample of 7,887 Medicare charts to determine how much of the change in Medicare's Case Mix Index between 1986 and 1987 was true change in the complexity of cases and how much was upcoding or ‘DRG creep’. About two-thirds of the change is true. Most of the remaining third is attributable to a general change in the completeness of coding; some is attributable to changes in the Grouper program. Thus, most of the additional $1 billion paid to hospitals because of the Case Mix Index change appears justified by the additional complexity of patients hospitalized.
Creating an American Mythology: A Comparison of Branding Strategies in Three Fashion Firms

AbstractFashion firms must formulate and promote an identity that will be meaningful and memorable. Ralph Lauren, Tommy Hilfiger, and American Apparel are brands that overtly define themselves as American. Each brand seeks out what they define as essential elements from the American cultural landscape. These elements are used to construct a unique and coherent narrative—or more precisely mythology—underscoring the values of the brand, and framing a lifestyle identity to be embodied within products and extended to the wearer. By formulating a culturally rich brand identity and presentation, the firm attempts to visually and textually seduce the target consumer. These three brands are linked through their acceptance of democracy as a common denominator defining an American identity; however, each brand links itself to radically different manifestations of American democracy.
Estrogen enhances gonadotropin-releasing hormone-stimulated transcription of the luteinizing hormone subunit promoters via altered expression of stimulatory and suppressive transcription factors.

Transcription of the LH subunit genes is stimulated by GnRH and may be modulated physiologically by steroids such as 17β-estradiol (E). We found that E treatment amplified GnRH stimulation of the rat LHβ and α-subunit promoters, and expression of the endogenous mRNA, in LβT2 gonadotrope cells 2- to 5-fold above GnRH alone. We examined gene expression in LβT2 cells after E and/or GnRH treatment, and found that E suppressed expression of transcription factor Zfhx1a, and enhanced GnRH stimulation of Egr-1 mRNA and protein. E effects were abolished in the presence of antiestrogen. Egr-1 is critical for LHβ expression; however, the role of Zfhx1a, which binds to E-box sequences, was untested. We found E-box motifs in both the rat LHβ (−381, −182, and −15 bp) and α-subunit (−292, −64, −58 bp) promoters. Zfhx1a overexpression suppressed basal and GnRH-stimulated activity of both promoters. Mutation of the α-subunit promoter E boxes at either −64 or −58 bp eliminated Zfhx1a suppression, whereas mutation of the −2...
Conversation with Herbert Blumer: II*

During the academic year 1977–1978, Professor Herbert Blumer sponsored Drs. Thomas J. Morrione and Harvey A. Farberman as Visiting Scholars in the sociology department of the University of California at Berkeley. In Fall Quarter of 1977, Morrione and Farberman attended Blumer's class and taped and transcribed six of the ten lecture/discussions. The transcripts were reviewed during Winter Quarter and questions, in writing, were prepared and delivered to Blumer for subsequent exploration. In Spring Quarter of 1978, Blumer, Morrione, and Farberman met four times (for a total of about 20 hours) to discuss these questions. A 232 page typescript was produced from recordings of these sessions. A year later, in Spring Quarter of 1979, Blumer again gave his course in Symbolic Interaction (for the last time at Berkeley) and Farberman again taped them. In the Fall of 1979, prior to editing the 232 page typescript, Morrione and Farberman reviewed the tapes of Blumer's Fall 1977 and Spring 1979 classes and settled on an editorial strategy. Initially, two strategies were considered: a fairly straight forward chronology or an analytical reconstruction. Both had advantages and disadvantages. The first captures the informal, spontaneous, dialogical quality of purposeful conversation; but, it contains an abundance of false starts, convoluted sentences, mixed metaphors, leaps of logic, off-color remarks and, most especially—redundancy. The second offers a set of key notions adduced from the narrative that reflect, what the participants wish to focus on but clearly is an abridged version. Following a series of conversations with Peter M. Hall (then) Editor of Symbolic Interaction, it became clear that, publication of the material presupposed journal length segments of 25–30 pages. As a practical matter, the editorial strategy became analytic reconstruction. After two passes at the material, Morrione and Farberman agreed to a scheme that seemed most effective in organizing and containing all the key material. This scheme breaks the material into two manuscripts, one dealing with the nature of “self-indication,” the other with the “moral dimensions of action and the ethical dimension of investigation.” To offset some of the pitfalls inherent in analytic reconstruction, Morrione and Farberman followed four rules: (1) each participant held a veto and nothing was finalized on any point under review, unless and until agreement was reached; (2) each segment (line, paragraph, or page), no matter where it appeared in the reconstruction, was identified by its page number in the original narrative; (3) each participant would retain a bound copy of the original unexpurgated transcripts and, where appropriate and with the others' permission, make it available for wider scholarly use; and (4) nothing would be published unless it was reviewed and approved by Herbert Blumer.
Studies of smectite membrane behavior: Temperature dependence, 20-180°C

Abstract A brine 5.0 molal in NaCl and 0.45 molal in CaCl2 was forced through random-fabric clay cakes, 1.0 to 1.6 cm thick, prepared from the 0.25–2.7 μm diameter size fraction of Cheto montmorillonite from Chambers, Arizona. Runs were made at 20°, 95°, 140° and 180°C using a compaction pressure of 34.5 MPa (5000 psi), an upstream fluid pressure of 22.8 MPa (3300 psi), and a downstream fluid pressure of 8.96 MPa (1300 psi). An additional run was made at 140°C, a compaction pressure of 68.9 MPa (10,000 psi), an upstream fluid pressure of 39.0 MPa (5650 psi), and a downstream fluid pressure of 25.3 MPa (3650 psi). At constant fluid flow rate, the molal filtration efficiencies of both Na+ and Ca2+ increase with temperature, the latter more rapidly. The effect of compaction pressure is shown by comparing the two runs at 140°C: the filtration efficiency for Ca2+ at the higher compaction pressure was twice that at the lower compaction pressure; for Na+, it was 60% greater. At the slower flow rates found in nature, it appears that Ca2+ must be retained preferentially relative to Na+ in virtually all sedimentary environments, with the Ca2+ preference increasing with increasing temperature. The apparent membrane enrichment for the heavy oxygen isotopes of throughput water molecules observed at 140°C is 0.15%. and that at 180°C is 0.05%., values that are opposite in sign to those reported in the literature for 20°C. This apparent shift in enrichment with temperature is 4 to 5 times the room-temperature salinity correction, but the reliability of the shift value is reduced by the possibility in the high-temperature runs of exchange between brine and clay, which would also make the brine isotopically heavier. Observed changes in filtration efficiency of Ca2+ and Na+ with temperature and fluid velocity can be explained qualitatively using arguments involving fluid viscosity and hydraulic drag. The newly-designed membrane press used in the study performed adequately at temperatures up to 180°C, but failed in several respects at 220°C.
Unified Approach for LRFD Live Load Moments in Bridge Decks

Current AASHTO-LRFD specifications use many disparate design provisions to establish live load demands in bridge decks. As an example, approximately 17% of Chapter 4 addresses the analysis of decks. One of the AASHTO-LRFD analysis methods for decks uses an orthotropic plate model. The present AASHTO-LRFD orthotropic plate model has a single formulation for the plate torsional stiffness, and this is not generally applicable to all deck types. In this paper, new analytical expressions are developed for moment in bridge decks subjected to arbitrary patch loading considering each of the three cases of orthotropy: (1) relatively torsionally stiff, flexurally soft decks; (2) relatively uniformly thick decks (such as a reinforced concrete deck); and (3) relatively torsionally soft, flexurally stiff decks. Using these newly developed expressions, the AASHTO-LRFD notional live load models were combined with impact, multiple presence, and live load factors to determine maximum strong direction live load moments for...
Modification of the electron energy distribution function during lithium experiments on the National Spherical Torus Experiment

The National Spherical Torus Experiment (NSTX) has recently studied the use of a liquid lithium divertor (LLD). Divertor Langmuir probes have also been installed for making measurements of the local plasma conditions. A non-local probe interpretation method is used to supplement the classical probe interpretation and obtain measurements of the electron energy distribution function (EEDF) which show the occurrence of a hot-electron component. Analysis is made of two discharges within a sequence that exhibited changes in plasma fueling efficiency. It is found that the local electron temperature increases and that this increase is most strongly correlated with the energy contained within the hot-electron population. Preliminary interpretative modeling indicates that kinetic effects are likely in the NSTX.
Elevated BNP is Associated with Vasospasm-Independent Cerebral Infarction Following Aneurysmal Subarachnoid Hemorrhage

Background Elevated levels of B-type natriuretic peptide (BNP) have been associated with cardiac dysfunction and adverse neurological outcomes after subarachnoid hemorrhage (SAH). We sought to determine whether elevated levels of BNP are independently associated with radiographic cerebral infarction after SAH.
Silver-nanoparticle-embedded antimicrobial paints based on vegetable oil

Developing bactericidal coatings using simple green chemical methods could be a promising route to potential environmentally friendly applications. Here, we describe an environmentally friendly chemistry approach to synthesize metal-nanoparticle (MNP)-embedded paint, in a single step, from common household paint. The naturally occurring oxidative drying process in oils, involving free-radical exchange, was used as the fundamental mechanism for reducing metal salts and dispersing MNPs in the oil media, without the use of any external reducing or stabilizing agents. These well-dispersed MNP-in-oil dispersions can be used directly, akin to commercially available paints, on nearly all kinds of surface such as wood, glass, steel and different polymers. The surfaces coated with silver-nanoparticle paint showed excellent antimicrobial properties by killing both Gram-positive human pathogens (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli). The process we have developed here is quite general and can be applied in the synthesis of a variety of MNP-in-oil systems.
Runway Assignments That Minimize Terminal Airspace and Airport Surface Emissions

Air traffic operations at and around major airports in the United States are in need of improvement. From the perspective of arrivals, when one or more runways are in great demand, unnecessary delay and emissions occur during peak periods at major airports while other runways at the same airport are operating under capacity. The primary cause of this imbalance in runway utilization is that traffic flow into and out of terminal areas is asymmetric (as a result of airline scheduling practices) and arrivals are typically assigned to the runway nearest the fix through which they enter the terminal area. From the perspective of departures, delays and emissions are incurred because arrivals take precedence over departures with regard to the utilization of runways (despite the absence of binding safety constraints) and because arrival trajectories often include level segments that ensure “procedural separation” from arriving traffic while planes are not allowed to climb unrestricted along the most direct path to...
Migration and differentiation of neural precursors derived from human embryonic stem cells in the rat brain

Human embryonic stem (hES) cells provide a potentially unlimited cell source for regenerative medicine. Recently, differentiation strategies were developed to direct hES cells towards neural fates in vitro. However, the interaction of hES cell progeny with the adult brain environment remains unexplored. Here we report that hES cell-derived neural precursors differentiate into neurons, astrocytes and oligodendrocytes in the normal and lesioned brain of young adult rats and migrate extensively along white matter tracts. The differentiation and migration behavior of hES cell progeny was region specific. The hES cell-derived neural precursors integrated into the endogenous precursor pool in the subventricular zone, a site of persistent neurogenesis. Like adult neural stem cells, hES cell-derived precursors traveled along the rostral migratory stream to the olfactory bulb, where they contributed to neurogenesis. We found no evidence of cell fusion, suggesting that hES cell progeny are capable of responding appropriately to host cues in the subventricular zone.
The Growth, Steady State and Decay of the Photocarrier Population at low Temperatures

We used the transient infrared photoconductivity to measure the rise and fall of the non-equilibrium photocarrier concentration n at helium temperatures and the conditions for recombination. The growth rate of n was found to be only a few percent of the electron-hole pair generation rate G in agreement with LESR data of Street and Biegelsen. The saturation value of n is about 1017cm−3 and nearly independent of G. After turning off the generation light, the residual n requires an hour to decrease by a factor 2 but it can be made to recombine in seconds by infrared light.
Murine skin and vaginal mucosa are similarly susceptible to infection by pseudovirions of different papillomavirus classifications and species.

Abstract Depending upon viral genotype, productive papillomavirus infection and disease display preferential tropism for cutaneous or mucosal stratified squamous epithelia, although the mechanisms are unclear. To investigate papillomavirus entry tropism, we used reporter pseudovirions based on various cutaneous and mucosal papillomavirus species, including the recently identified murine papillomavirus. Pseudovirus transduction of BALB/c mice was examined using an improved murine skin infection protocol and a previously developed cervicovaginal challenge model. In the skin, HPV5, HPV6, HPV16, BPV1 and MusPV1 pseudovirions preferentially transduced keratinocytes at sites of trauma, similar to the genital tract. Skin infection, visualized by in vivo imaging using a luciferase reporter gene, peaked between days 2–3 and rapidly diminished for all pseudovirion types. Murine cutaneous and genital tissues were similarily permissive for pseudovirions of HPV types 5, 6, 8, 16, 18, 26, 44, 45, 51, 58 and animal papillomaviruses BPV1 and MusPV1, implying that papillomavirus' tissue and host tropism is governed primarily by post-entry regulatory events in the mouse.
Enhancing Field‐Effect Mobility of Conjugated Polymers Through Rational Design of Branched Side Chains

The design of polymer semiconductors possessing effective π–π intermolecular interactions coupled with good solution processability remains a challenge. Structure-property relationships associated with side chain structure, π–π intermolecular interactions, polymer solubility, and charge carrier transport are reported for a donor–acceptor(1)-donor–acceptor(2) polymer: 5-Decylheptadecyl (5-DH), 2-tetradecyl (2-DT), and linear n-octadecyl (OD) chains are substituted onto a polymer backbone consisting of terthiophene units (T) between two different electron acceptors, benzothiadiazole (B), and diketopyrrolopyrrole (D), pTBTD, to afford pTBTD-5DH, pTBTD-2DT, and pTBTD-OD, respectively. In the 5-DH side chain, the branching position is remote from the polymer backbone, whereas it is proximal in 2-DT. This study demonstrates that incorporation of branched side chains where the branching position is remote from the polymer backbone merges the advantages of improved solubility from branched units with effective π–π intermolecular interactions normally associated with linear chains on conjugated polymers. pTBTD-5DH exhibits superior qualities with respect to the degree of polymerization, solution processability, π–π interchain stacking, and charge carrier transport relative to the other analogs. pTBTD-5DH exhibits a field-effect hole mobility of up to 2.95 cm2 V–1 s–1, a factor of 3–7 times that achieved with pBDT6-DT and pBDT6-OD.
A computational approach to the spectrophotometric determination of stability constants—II: Application to metalloporphyrin-axial ligand interactions in non-aqueous solvents

Abstract The ability of the computer program SQUAD to deduce a plausible equilibrium model, associated stability constants and spectra of individual species is described. The original version of SQUAD has been extensively modified and these changes are detailed. In particular a “user-friendly” method of data input has been implemented that simplifies familiarization with the program. Brevity of program code has been sacrificed in favour of the new data input and error-checking features of SQUAD, with beneficial results. The application of SQUAD to five non-aqueous metalloporphyrin-axial ligand interactions exemplifies the program's ability to handle widely different types of equilibrium systems.
Stereoscopic particle image velocimetry measurements of the flow around a Rushton turbine

The principles of stereoscopic particle image velocimetry (PIV), including distortion compensation, were applied to the turbulent flow in a vessel stirred by a Rushton turbine. An angular offset configuration was used and tilt-axis lens mounts were incorporated in order to satisfy the Scheimpflug condition, significantly reducing the ordinarily large depth of field requirements of such configurations. A distortion compensation procedure, or in situ calibration, was utilized in place of the ray tracing, or mechanical registration, used in previous studies. The calibration procedure was validated using two tests, one a rigid translation of a speckle target, the other the viscous flow between two concentric cylinders. The results of the tests suggest the success with which the distortion compensation procedure may be applied to real fluid flows. Phase-locked instantaneous data were ensemble averaged and interpolated in order to obtain mean 3-D velocity fields on a cylindrical shell enclosing the turbine blade. From these fields, the tip vortex pairs and the radial jet documented in previous studies of mixer flows were easily identified.
Refractive Index and Scattering Effects on Radiation in a Semitransparent Laminated Layer

Heat transfer characteristics are analyzed for a laminated layer of two semitransparent scattering materials with refractive indices larger than one. Each side of the composite is heated by radiation and convection. Energy is transferred internally by conduction, emission, absorption, and isotropic scattering. The external surfaces of the composite and its internal interface are diffuse, which is intended to model composite ceramics in hightemperature applications. The two sublayers can have differing refractive indices greater than one. This causes internal reflection of some energy within the layers. Coupled with scattering, this has a substantial effect on the temperature distribution. Results are given for various optical thicknesses and refractive indices of the sublayers, and for scattering albedos up to one. Comparisons of numerical solutions are made with limiting cases based on the pure scattering, radiative diffusion, transparent, and opaque limits in the individual layers. The limiting solutions are very useful because they are convenient to evaluate and provide accurate results for many cases of interest.
Technological innovations and publications related to space science education

Abstract As NASA Administrator Dan Goldin has noted, children are especially interested in three things: ghosts, dinosaurs, and space. We need to capitalize on the interest in space to develop and encourage a continuing understanding and curiosity about space-related issues from the grade school level through adulthood. Unfortunately, because astronomy is usually only offered in college as an introductory-level elective or as a specialized area of graduate study, most pre-college educators are uncomfortable teaching space sciences in the classroom. Additionally, the particularly dynamic nature of the field leaves educators with materials that are out-of-date and inadequate. In the framework of the new educational pedagory focusing on hands-on activities, this paper presents a discussion of technologically innovative resources for the space science classroom (primarily at the high school level) which utilize hands-on activities for the students. The discussion will focus in five areas: major high-tech programs (which require specialized equipment in the schools), national and local workshops available to educators, hands-on activities commercially available, educational astronomical resources, and examples of hands-on activities developed and expanded upon by teachers and astronomers attending an educational workshop in Hawai`i from 1993–1995.
Accumulation of axoplasmic organelles in swollen nerve fibers

Abstract The density of axoplasmic organelles in swollen fibers was determined with a method of line sampling and was correlated with the degree of axonal swelling. A linear relation was found between axon swelling and the density of axoplasmic organelles. The latter occupied less than 9% of the axoplasm in normal nerve fibers and approximately 30% in excessively swollen fibers. The total combined volume of organelles per maximally swollen fiber was approximately 12 times normal, enough to fill the entire axis cylinder before the onset of swelling. The same correlation was found between the degree of swelling and the increase in organelle density in myelinated and non-myelinated fibers. This indicates that the primary events responsible for axonal swelling occurred within the axoplasm, and that the process of sheath expansion was only incidental to these primary axonal changes. The changes in the density of axoplasmic organelles corresponded to their reorientation between neurofilaments and microtubules. In normal axons, mitochondria and smooth endoplasmic reticulum were aligned in succession within ‘cytoplasmic streets’ between the bundles of neurofilaments and microtubules, all with their long axes parallel to the fiber. In moderately swollen fibers, the ‘streets’ were enlarged and crowded with organelles. Markedly swollen fibers showed a loss of neurofilamentous material and a lack of alignment of organelles. The identification of axoplsmic organelles, theories of axonal flow, and mechanism producing reactive axonal swelling are discussed.
T helper 1-type immunity to trophoblast antigens in women with a history of recurrent pregnancy loss is associated with polymorphism of the IL1B promoter region.

T helper 1-type immunity to trophoblast antigens in women with a history of recurrent pregnancy loss is associated with polymorphism of the IL1B promoter region