cssi/SciSciGPT-SciSciNet huggingface dataset:
A 39.1-to-41.6GHz ΔΣ Fractional-N Frequency Synthesizer in 90nm CMOS

In this paper, we present a 39.1-to-41.6 GHz 1.2 V 64 mW DeltaSigma fractional-N frequency synthesizer that is implemented in 90nm CMOS. To reduce power consumption, a divide-by-4 injection-locking frequency divider (ILFD) is used in the feedback loop and a digital calibration technique is implemented to overcome the ILFD locking-range limitations.
Physical genome map of the unicellular cyanobacterium Synechococcus sp. strain PCC 7002.

Abstract A physical restriction map of the genome of the cyanobacterium Synechococcus sp. strain PCC 7002 was assembled from AscI, NotI, SalI, and SfiI digests of intact genomic DNA separated on a contour-clamped homogeneous electric field pulsed-field gel electrophoresis system. An average genome size of 2.7 x 10(6) bp was calculated from 21 NotI, 37 SalI, or 27 SfiI fragments obtained by the digestions. The genomic map was assembled by using three different strategies: linking clone analysis, pulsed-field fragment hybridization, and individual clone hybridization to singly and doubly restriction-digested large DNA fragments. The relative positions of 21 genes or operons were determined, and these data suggest that the gene order is not highly conserved between Synechococcus sp. strain PCC 7002 and Anabaena sp. strain PCC 7120.
The Worm Propagation Model with Dual Dynamic Quarantine Strategy

Internet worms are becoming more and more harmful with the rapid development of the Internet. Due to the extremely fast spread and great destructive power of network worms, strong dynamic quarantine strategies are necessary. Inspired by the real-world approach to the prevention and treatment of infectious diseases, this paper proposes a quarantine strategy based on dynamic worm propagation model: the SIQRV dual quarantine model. This strategy uses dynamic quarantine method to make the vulnerable host and infected host quarantined, and then release them after a certain period of time, regardless of whether quarantined host security is checked. Through mathematic modeling, it has been found that when the basic reproduction number R0 is less than a critical value, the system will stabilize in the disease-free equilibrium, that is, in theory, the infected hosts will be completely immune. Finally, by comparing the simulation results and numerical analysis, the basic agreement between the two curves supports the validity of the mathematical model. Our future work will be focusing on taking both the delay and double-quarantine strategy into account and further expanding the scale of our simulation work.
A Pedagogical Approach to Writing E-books

Resumo: Electronic books, or e-books, have the potential of filling an important niche in the publishing of textbooks. We discuss two wiki-based e-books that we have created illustrating a sustainable model, which can be followed by other instructors and institutions. We consider the questions of quality and sustainability for e-books. Abstract: Electronic books, or e-books, have the potential of filling an important niche in the publishing of textbooks. We discuss two wiki-based e-books that we have created illustrating a sustainable model, which can be followed by other instructors and institutions. We consider the questions of quality and sustainability for e-books.
Studies of the McGurk effect: implications for theories of speech perception

Studies of the McGurk effect (McGurk and MacDonald, 1976) demonstrate that observers integrate auditory information with visual information from a talker's face during speech perception. The findings from these studies pose challenges for theories of speech perception that must account for how and why the auditory and visual information are integrated. One theoretical issue concerns the objects of speech perception. Some researchers claim that the objects of speech perception are articulatory gestures while others argue that the objects are auditory in nature. The McGurk effect is often taken as evidence for gestural approaches because such theories provide a good account for why the auditory and visual information are integrated during perception. The findings from various studies of the McGurk effect, including cross-modal context effects, developmental influences and neuromagnetic measures of brain activation are reviewed. The implication of these findings are discussed with regard to whether the metric for combining the auditory and visual information is best thought of as auditory or gestural in nature.
Discharge of tile drainage systems in an irrigated area of California

Measurements of discharge from the drains in the Coachella Valley of California have been plotted, and a simple equation has been developed, to give maximum discharge in terms of drainage area or length of tile. It has not been possible as yet to relate the coefficients or exponents involved to differences in soil characteristics or irrigation practices, but as more information is developed this may be possible. Good data on which to base the design capacity of tile drains in irrigated areas have been lacking. The ‘drainage coefficient’ used in humid areas is not applicable, and the ponded condition, which would permit rational calculation of discharge (Kirkham, 1949) is not reached. The information here developed is presented as a first step towards solution of the problem.
Extending the Boundaries: Reframing “Entrepreneurship as Social Change” Through Feminist Perspectives

We engage in a critical theoretical exercise to extend the boundaries of entrepreneurship theory and research by reframing “entrepreneurship as positive economic activity” to “entrepreneurship as social change.” Reframing entrepreneurship through feminist analytical lenses, we argue that more theoretical frameworks are needed for exploring the varieties of social change that entrepreneurship may bring about. We also discuss what difference this would make in extant entrepreneurship perspectives. Theoretically, methodologically, and analytically, such reframing is the main contribution of this paper.
Rereading the Gettysburg address: Social change and collective memory

Recent scholarship depicts the Gettysburg Address as an unchanging symbol of American democracy. This investigation shows new meanings of the Gettysburg Address arising as successive generations interpret it in light of new situations and challenges. Lincoln's supporters interpreted the Gettysburg Address as a call to arms, a plea to grasp the victory that the Union's dead had brought into sight. Throughout the late nineteenth century, the Gettysburg Address was recognized for its aesthetic appeal, but rarely commemorated. As early twentieth-century Progressive reforms redistributed political power, as Northerners and Southerners renounced old hatreds, and as foreign wars enhanced America's global role, the Gettysburg Address became a multivalent symbol of industrial democracy, regional solidarity, and patriotism. Abraham Lincoln's Address assumed its present meaning, which incorporates the often conflicting ideals of racial equality and regional unity, in the late twentieth-century. As the “cultural revolution” of the 1960s expanded, Lincoln's prestige fell dramatically. Lincoln, paradoxically, was reduced by the power of the egalitarian ideal he symbolized—even as that ideal became embodied in his own words. To resolve this paradox, postmodernist conceptions of author-reader relations are brought to bear on current understandings of collective memory.
Dielectrophoretic discrimination of bovine red blood cell starvation age by buffer selection and membrane cross-linking

We report an interesting buffer electric relaxation time tuning technique, coupled with a glutaraldehyde cross-linking cell fixation reaction, which allows for sensitive dielectrophoretic analysis and discrimination of bovine red blood cell (bRBC) starvation age. The buffer composition is selected such that two easily accessible dielectrophoretic crossover frequencies (cof) exist. Low concentration glutaraldehyde fixation was observed to produce a threefold decrease in the higher cof with a comparable increase in the lower cof also witnessed. More importantly, increased glutaraldehyde fixation concentration significantly increased the higher cof by a factor found to be sensitive to the bRBC starvation age.
Flows around sunspots and pores

We report on three sequences of high-resolution white-light and magnetogram observations obtained in the summer of 1989. The duration of sub-arcsecond seeing was three to four hours on each day. Study of the white-light and magnetogram data yields the following results:
IL-1 Receptor antagonist as a positional candidate gene in a murine model of allergic asthma

Interleukin-1 receptor antagonist (IL-1ra) is an inhibitor of the proinflammatory IL-1. The IL-1ra gene (Il1rn) maps near the allergen-induced bronchial hyper-responsiveness-1 locus, Abhr1, which we previously mapped to murine chromosome 2 using A/J (asthma susceptible) and C3H/HeJ (asthma resistant) mice. We evaluated the role of Il1rn in our mouse model by comparing its genomic sequence between A/J and C3H/HeJ mice as well as assessing strain-specific RNA and protein production in response to allergen. We identified no functional sequence variations in the Il1rn gene between A/J and C3H/HeJ mice. Il1rn mRNA and protein were induced by ovalbumin (OVA) exposure in both strains, but to a greater extent in A/J mice at the earlier time points. We examined other IL-1 family members (Il1a, Il1b, Il1f9, and Il1r2) and found OVA-induced expression increases at 6 h, yet only Il1b and Il1f9 had strain-specific differences. Of these, only Il1f9 is located within Abhr1, and we found several non-coding polymorphisms in the Il1f9 gene between A/J and C3H/HeJ mice. Our results exclude Il1rn as the gene for Abhr1 and indicate that Il1f9 warrants further investigation based on genetic and expression differences observed in our mouse model of allergic asthma.
Dark Chamber and Light-Filled Room: Vermeer and the Camera Obscura

For over thirty years the literature on Vermeer of Delft has included first hints, then suggestions and, finally, all but direct statements that Vermeer used the forerunner of the modern photographic camera, the camera obscura, as an aid in making his paintings. Although Wilenski in the late 1920's put much more emphasis on the use of mirrors than on the camera obscura, he pointed to certain effects (distorted enlargement in foreground objects, for example) which can be observed in photographs and noted as “perhaps one of the ironies of art history that with a Kodak any child might now produce by accident a composition that a great artist like Vermeer had to use all his ingenuity … to achieve.”1 More penetrating was Hyatt Mayor's discussion in 1946 of the evidence favoring Vermeer's use of a mechanical aid; here he spoke not only of distortion in size of near objects, but of the tonality of Vermeer's color which he “blended as perfectly as the ground glass of a camera” and of the highlights on foreground ...
Mappings with a single critical point and applications to rational difference equations

Convergence properties of first-order difference equations of the form are established for a general class of mappings f, where f has at most one critical point. Using these results, we find necessary and sufficient conditions for the convergence of the solutions for all difference equations of the formfor all possible choices of non-negative coefficients and positive initial values.
Future directions in photochemical air quality modeling

Photochemical air quality models provide the most defensible method for relating future air quality to changes in emission, and hence are the foundation for determining the effectiveness of proposed control strategies. However, strategies, based primarily on controlling reactive organic gas emissions, have not provided the expected benefits. This raises the question of what have been the deficiencies in previous studies utilizing these tools? Furthermore, what changes are necessary, and desired, to improve upon past efforts? The current generation of models have matured within their original frameworks to represent, relatively accurately, the important physical and chemical processes affecting pollutant dynamics in urban atmospheres. The ability to follow regional dynamics is less well demonstrated. Current regional models have a single horizontal resolution scale. Multiscale models will enable detailed treatment of urban chemistry, and also effectively follow long range transport and chemistry. Improved computational capabilities will allow more detailed chemistry and heterogeneous processes to be followed within the models. The practice of photochemical modeling will benefit greatly from recent and future intensive field studies. The advancements in both the model framework and practice will allow much more accurate evaluation of proposed control strategies, and lead to a much improved understanding of pollutant dynamics.
Rapid Estimation of Left Ventricular Contractility from End-Systolic Relations by Echocardiographic Automated Border Detection and Femoral Arterial Pressure

Background: Automated echocardiographic measures of left ventricular (LV) cavity area are closely correlated with changes in volume and can be coupled with LV pressure to construct pressure-area loops in real time. The objective was to rapidly estimate LV contractility from the end-systolic relations of cavity area (as a surrogate for LV volume) and femoral arterial pressure (as a surrogate for LV pressure) in patients undergoing cardiac surgery. Methods: Studies were attempted on 18 consecutive patients with recordings of LV pressure, LV area, and femoral arterial pressure on a computer workstation interfaced with the ultrasound system. End-systolic pressure-area relations (in terms of pressure-area elastance [E'(es)]) from pressure-area loops during inferior vena caval occlusions were determined before and immediately after cardiopulmonary bypass using both LV and arterial pressure by semiautomated and automated iterative linear regression methods. Results: Data sets were available for 13 patients before and 8 patients after bypass (21 studies in 14 patients). E'(es) by arterial pressure was closely correlated with E'(es) by LV pressure: r = 0.96, standard error of the estimate = 2 mmHg/cm2, y = 1.01 x -0.7 by the semiautomated method and r = 0.94, standard error of the estimate = 3 mmHg/cm2, y = 1.02 x -0.5 by the automated method. Analysis of semiautomated and automated estimates of E'(es) from arterial pressure and E'(es) using LV pressure by the Bland-Altman method showed no systematic measurement bias and calculated limits of agreement of 8 and 9 mmHg/cm2, respectively. Similar decreases in E'(es) by arterial and LV pressure occurred from before to after bypass in 7 patients with paired data sets: 32 ± 12 to 15 ± 6 mmHg/cm2 and 32 ± 15 to 15 ± 7 mmHg/cm2, respectively (P < 0.05 for both). Conclusions: On-line femoral arterial pressure and LV area data by echocardiographic automated border detection may be used to rapidly calculate E'(es) as a means to estimate LV contractility in selected patients.
THz spectroscopy of ceramic and polycrystalline materials for characterization of microwave dielectric properties

Theoretically expected frequency and temperature dependence of weak multiphonon bands at the far infrared absorption band edge are used to develop classical oscillator models of permittivity for several window materials (sapphire, ZnS and Pyroceram® 9606) which accurately model dielectric behavior from the infrared through the THz and into the microwave regions.
Increased restrictive feeding practices are associated with reduced energy density in 4–6-year-old, multi-ethnic children at ad libitum laboratory test-meals ☆

Increased reports of restrictive feeding have shown positive relationships to child obesity, however, the mechanism between the two has not been elucidated. This study examined the relationship between reported use of restrictive feeding practices and 4-6-year-old children's self-selected energy density (ED) and total energy intake from an ad libitum, laboratory dinner including macaroni and cheese, string beans, grapes, baby carrots, cheese sticks, pudding, milks, and a variety of sweetened beverages. A second objective explored the relationship between ED and child body mass index (BMI) z-score. Seventy (n=70) healthy children from primarily non-Caucasian and lower socioeconomic status families participated. Mothers completed the Child Feeding Questionnaire (CFQ) to assess restrictive feeding practices. Energy density (kcal/g) values for both foods and drinks (ED(food+drink)) and ED for foods only (ED(foods)) were calculated by dividing the average number of calories consumed by the average weight eaten across 4 meals. Higher maternal restriction was associated with lower ED(food+drink). In overweight and obese children only, higher maternal restriction was associated with lower ED(food). There was a non-significant trend for both ED measures to be negatively associated with child BMI z-score. Overall, restrictive feeding practices were not associated with child BMI z-score. However, when analyzing separate aspects of restriction, parents reported higher use of restricting access to palatable foods but lower use of using palatable foods as rewards with heavier children. Previous reports of positive associations between child obesity and restrictive feeding practices may not apply in predominantly non-Caucasian, lower socioeconomic status cohorts of children.
Neutron-rich rare isotope production in the Fermi energy domain and application to the Texas A&M radioactive beam upgrade

The production and separation of neutron-rich rare isotope beams in peripheral collisions around the Fermi energy is described in the present work. The experiments were performed at the Cyclotron Institute of Texas A&M University employing beams from the K500 Superconducting Cyclotron. Two magnetic separators were used: the MARS recoil separator and the Superconducting Solenoid Line (BigSol Line). Enhanced production cross sections of neutron-rich nuclides in comparison with high-energy fragmentation mechanisms were observed and attributed to the role of the N/Z and the nuclear periphery of the target. From a practical viewpoint, these reactions below or around the Fermi energy offer a promising way to access very neutron-rich rare isotopes. The experience obtained in the production of rare isotope beams (RIB) in this energy range will be applied in the ongoing RIB upgrade of the Cyclotron Institute that will involve production, stopping and re-acceleration of rare isotopes.
Effects of actual versus arbitrary awake and sleep times on analyses of 24-h blood pressure.

Investigators conducting hypertension trials with ambulatory blood pressure (BP) monitoring have been analyzing study results using arbitrary times for day (wakefulness) and night (sleep). We prospectively evaluated the impact of using arbitrary times instead of patient reported awake and sleep times on mean 24-h, awake, and sleep BP, BP loads, and the awake-sleep BP difference in 50 subjects. Daytimes and nighttimes were derived from popular, arbitrary times reported in the literature. Compared to actual awake and sleep periods, arbitrary day and night division caused no significant differences in the mean awake and sleep BPs. However, limits of agreement for BP values derived for the actual and arbitrary times of wakefulness and sleep were substantial especially during sleep (awake systolic BP, −4 to 7 mm Hg; awake diastolic BP, −2 to 4 mm Hg; sleep systolic BP, −12 to 7 mm Hg; and sleep diastolic BP −7 to 4 mm Hg). Sleep BP loads (proportion of BPs >120/ 80 mm Hg) were altered by greater than 10% in 20% to 30% of the subjects, depending on choice of time schedule. These data demonstrate that the calculation of BP and BP load during sleep may be altered by use of arbitrary, rather than actual, times of wakefulness and sleep in 24-h studies of ambulatory BP.
Caffeine and paraxanthine pharmacokinetics in the rabbit: concentration and product inhibition effects.

The disposition of caffeine (C) and its major metabolite paraxanthine (P) have been determined following i.v. bolus dosing both separately and concomitantly to New Zealand White rabbits. Caffeine clearances of 1.52–6.71 ml/mm/kg were observed and were suggestive of polymorphism with rapid (type I) and slow (type II) metabolizing subpopulations represented. Type II metabolizers exhibited dose-independent pharmacokinetics for C, while the clearances of type I animals were dose-dependent (lower clearances at higher doses). The P clearances were not dose-dependent. In type I rabbits coadministration of P inhibited C metabolism by as much as 71%. Results were consistent with the hypothesis that at least two farms of cytochrome “P-450” mediate the metabolism of C in the rabbit.
Use of immobilized carboxypeptidase Y (I-CPY) as a catalyst for deblocking in peptide synthesis.

Resume CPY est une carboxypeptidase de levure de tres large specificite. En plus d'une activite exopeptidasique a pH acide, l'enzyme est une esterase a pH basique. A partir de ces observations, nous decrivons une synthese peptidique sequentielle utilisant la CPY immobilisee pour debloquer le carbone terminal. Toutes les operations peuvent etre conduites dans l'eau pres de la neutralite ce qui elimine de nombreuses reactions parasites.
Reaction of benzotriazole ultraviolet light absorbers with free radicals

Abstract The photolysis of benzotriazole ultraviolet light absorber additives (Bz-UVAs) in acrylic/melamine clearcoats suggests that Bz-UVAs are destroyed by clearcoat-driven photooxidation chemistry. Tinuvin 900 is converted to parent benzotriazole and phenol ring oxidation products. Bz-UVAs are not destroyed by photolysis in acrylic/melamine clearcoats in the absence of oxygen. Solution photolysis experiments reveal that Bz-UVAs are not attacked by free radicals generated by thermal decomposition of azoisobutyronitrile (AIBN) or cumene hydroperoxide (CHP) in ethanol or cyclohexane. Bz-UVAs are also not attacked by free radicals generated by photolytic decompostion of AIBN or CHP in cyclohexane. Bz-UVAs, however, are destroyed when AIBN or CHP are photolytically decomposed in ethanol. Photolysis without oxygen leads to Bz-UVA phenol ring solvent and initiator adducts. Photolysis with oxygen leads to cleavage to form free benzotriazole and to destruction of the phenol ring. It is suggested that an excited state of the non-planar Bz-UVA form may be susceptible to free radical attack. Detailed liquid chromatography tandem mass spectrometry (LC/MS/MS) product analysis results are reported in a companion paper.
Evaluation of in-vitro cell labelling of mouse epithelia with tritiated thymidine

Abstract Various factors affecting the epithelial labelling index recorded following in-vitro incubation of specimens of mouse skin and palatal mucosa with tritiated thymidine were examined. Isotope concentration, specimen size and the period of exposure of autoradiographs prior to development markedly influenced the labelling index recorded but, following standardization of such factors, a reproduceable index could be obtained. Labelling indices comparable to those obtained by the standard in-vivo labelling method could be produced by adjustment of isotope concentration in incubation media. Comparison of labelling indices recorded for tissues labelled in-vitro by a standardized method appears valid but the absolute values of indices so obtained and their comparison with indices resulting from in-vivo labelling methods are of doubtful significance.
A-mode speckle reduction with compound frequencies and compound bandwidths

A simple model for predicting the degree of speckle reduction in A-mode images via the correlation coefficient was tested experimentally. The model appeared to account correctly for the influence of image system bandwidth on frequency separations required for nearly independent sampling in compound frequency imaging. Moreover, the notion of compound bandwidth imaging was tested; the correlation between samples at different bandwidths decreased as the ratio of bandwidths decreased.
The logarithmic Minkowski problem for polytopes

Abstract The logarithmic Minkowski problem asks for necessary and sufficient conditions for a finite Borel measure on the unit sphere so that it is the cone-volume measure of a convex body. This problem was solved recently by Boroczky, Lutwak, Yang and Zhang for even measures (Boroczky et al. (2013) [8] ). This paper solves the case of discrete measures whose supports are in general position.
Ouabain-resistant mechanism of volume control and the ultrastructural organization of liver slices recovering from swelling in vitro.

We have studied the net extrusion of water by liver slices recovering from swelling at 1°C and have attempted to relate this to ultrastructural alterations. Special attention was paid to the ouabain-resistant extrusion of water. The restoration of many details of intracellular architecture was dissociated from the net loss of water, since an osmotic stimulus (produced by 5% inulin) caused a passive withdrawal of water with little recovery of structure. Also, a similar recovery of structure was produced during active extrusion of water in the absence and presence of ouabain, even though ouabain reduced the water extrusion by 50%. The time-course of water extrusion in the presence of ouabain was correlated with the formation of cytoplasmic vesicles. Incubation without K+ in the medium had similar effects to those caused by ouabain. Colchicine had little effect on water extrusion in presence or absence of ouabain except at concentrations which reduced tissue ATP levels and caused much necrosis. Cytochalasin B alone had little effect on water extrusion, but led to the accumulation of many vesicles in the cytoplasm and appeared to abolish the access of such vesicles to the canaliculi. In the presence of ouabain, cytochalasin B had a similar effect on ultrastructure, and totally prevented the ouabain-resistant water extrusion. Ni2+ had rather similar effects to cytochalasin B both in the presence and absence of ouabain, although to a smaller degree. The results support our previous suggestion that the ouabain-resistant water extrusion proceeds by secretion of water into cytoplasmic vesicles, followed by the exocytotic expulsion of the vesicular contents into the bile canaliculi. Microfilaments appear to play an important role in this process.
A research agenda to promote affordable and quality assured medicines

Promoting generic medicines to increase access to essential medicines is relevant to achieve the Millennium Development Goal (MDGs) and post 2015 goals.
Characteristics and completeness of clinical trial registrations in psoriasis and atopic dermatitis.

Summary Background Controversy over the failure to publish results of clinical trials linking antidepressant treatment to suicidal behaviour in adolescents has increased interest in clinical trial registration. Objective To assess numbers, characteristics and completeness of registrations of trials for psoriasis and atopic dermatitis registered at two web-based trial registries: ClinicalTrials.gov and isrctn.org. Methods In this cross-sectional study we identified trials by searching ClinicalTrials.gov and isrctn.org on 18 January 2006 for trials registered up to 31 December 2005. We included only trials of therapeutic interventions for atopic dermatitis or psoriasis. We ascertained the date of submission of registration, the funding source of the trial, and whether a registration listed the specific name of the intervention studied, the specific outcome measure used (e.g. ‘Psoriasis Area and Severity Index’), the criterion used to gauge success on the outcome measure (e.g. ≥ 75% decrease), and the time at which the outcome would be assessed (e.g. at 12 weeks). Results There were 156 registered trials, including 128 (82%) at ClinicalTrials.gov [36 (23%) in atopic dermatitis, 92 (59%) in psoriasis] and 28 (18%) at isrctn.org [23 (15%) in atopic dermatitis, 5 (3%) in psoriasis]. Pharmaceutical companies funded 87 trials (56%), federal or governmental agencies 28 (18%), universities or organizations 21 (13%), and a combination of funders 20 (13%). Of atopic dermatitis trials (13 of 36) and (24 of 92) of psoriasis trials at ClinicalTrials.gov were registered in September 2005. The specific name of the intervention studied was listed in 150 registrations (96%), 89 (57%) listed the specific measure used, 69 (44%) listed the criteria to gauge success and 62 (40%) listed the time of assessment. Conclusions While trial registrations in atopic dermatitis and psoriasis are increasing, more complete information in these registrations may increase their value for dermatologists and their patients.
Boy/girl differences in household work

Ordinary least squares multiple regression was used to model time spent in household work by children, aged 6–19, in 2,100 two-parent, two-child households in 11 states. First-born boys and girls and second-born boys and girls were analysed separately. Whether the data were collected on a schoolday was not significant in predicting all children's time in household work. Own age in both linear and quadratic forms was significant in explaining time of first-born boys and second-born girls, while living in a rural area was significant for second-born girls only. First-born boys were found to contribute significantly less time to household work than first-born girls.
Comments on “thermochemical investigations of associated solutions. 9. Prediction of excess enthalpies of ternary acetone + cyclohexane + chloroform mixtures from measured binary data”

Abstract A conventional non-electrolyte solution model which has led to successful predictive expressions for the thermochemical properties of a solute in simple binary solvent mixtures is extended to ternary systems having AC and AC 2 molecular complexes. The general mixing model used assumes that the Gibbs free energy of mixing and excess enthalpy can be separated into a chemical and a physical term. The chemical-interaction term results from the formation of molecular complexes and the physical contribution describes non-specific interactions between the uncomplexed and associated species in solution. Ten A ij parameters are initially needed to describe all the binary non-specific interactions present. Simplifying approximations and mathematical manipulations reduce the number of binary interaction parameters to only three A ij values. Expressions derived from the general mixing model are used to estimate the excess enthalpies of ternary acetone + cyclohexane + chloroform mixtures.
Measurement of Harmonic Impedances of Supply Systems Using Natural Disturbances

This paper presents a novel and practical method for monitoring harmonic impedances of power systems seen at load serving substations. The method uses the natural load fluctuations measured at the substation for impedance estimation. It avoids the needs for intrusive disturbances and can be used for online tracking of impedance parameters. The method has been verified through several real field measurements.
FLUORESCENCE STUDIES ON PHOTOSYNTHETIC PIGMENT DEVELOPMENT IN RHODOPSEUDOMONAS SPHEROIDES

— When bleached, aerobically grown cells of Rhodopseudomonas spheroides are transferred to semi-aerobic conditions to induce bacteriochlorophyll synthesis, a new fluorescence band, with a maximum at 790 nm, is observed in addition to the 885 nm emission maximum normally seen in pigmented cells. The 790 nm fluorescence may be due to bacterio-chlorophyll which has not been bound into the chromatophore membrane. The quantum yield of the 885 nm fluorescence is at first relatively high and then, about 1 hour after transfer, drops to the level found in pigmented photosynthetic cells. The coupling to the rest of the photo-synthetic apparatus, as indicated by the effect of dithionite on the fluorescence, also seems to occur during the first hour of pigment development, which suggests that the onset of fluorescence quenching is due at least in part to the synthesis of photochemical reaction centers. Continuation of these studies should provide new information on the formation, structure and molecular interactions of the pigments and the photosynthetic membranes.
Interaction of protein percent with caloric density and protein source for lactating cows.

Abstract Experiment 1 was to test effect of three ratios of energy to protein in complete mixed diets for 36 lactating cows in three, 28-d periods. Energy was varied with cottonseed hulls, pelleted ground corrugated boxes, and a mixture of the two. Crude protein was varied with soybean meal to give energy:crude protein of 5.7, 5.0, and 4.6 for each energy amount. Cottonseed meal was compared with soybean meal in corrugated box diets. Feed intake was much higher with cottonseed hulls, and appreciable feedlot bloat resulted from pelleted ground corrugated box diets. Data adjusted to equal feed intake showed significant effect of energy to crude protein ratio on milk yield and improved digestion of organic matter with soybean meal vs. cottonseed meal. Experiment 2 tested the hypothesis that lactating cows consuming high-protein alfalfa may benefit from supplemental protein. Diets were 50% forage. Six diets were 14 or 18% crude protein in three ratios of alfalfa hay to corn silage (0:100, 50:50, 100:0). Additional corn silage diets were to compare: 14 versus 18% protein from distiller's dried grains with solubles only and with .5 or .9% urea (four diets); two 14% protein diets compared .6% added potassium chloride with or without .5% urea. Thirty-six Holstein cows in early lactation received one of the 12 diets in each of three 28-d periods. Distiller's grains with solubles markedly depressed milk yield (2.2 kg/d) and milk protein (.22%); heat damage of distiller's grains was evident. Protein interacted with alfalfa so gain in milk from 18 versus 14% increased from .55 to 1.36 to 2.66 kg/d as alfalfa changed from 0 to 50 to 100%. Thus, crude protein of alfalfa was not as effective as that from soybean meal in supporting milk yield.
Semi-insulating polysilicon heterojunctions on silicon

Abstract The electrical characteristics of undoped semi-insulating polysilicon (SIPOS)/p-type crystalline silicon (p-Si) and N + -SIPOS/p-Si heterojunctions were investigated. The current-voltage characteristics of the undoped SIPOS/p-Si heterojunctions depart from a hyperbolic sine behavior as the refractive index of the SIPOS increases. Carrier conduction in the undoped heterojunctions is characterized by low- and high-temperature barrier heights, which also vary with refractive index. Current-voltage characteristics of the n + -SIPOS/p-Si structures were rectifying with a cut-in voltage of about 1 V, which decreased with increasing temperature. Increasing the SIPOS doping increased the current density for a given bias and reduced the cut-in voltage. The forward characteristic displayed both a low and a high field activation energy with the difference attributable to the presence of interface states at the junction. Consequently, carrier conduction in these doped and undoped SIPOS/p-Si heterojunctions appears to be controlled by the SIPOS/p-Si interface. However, hydrogen annealing passivates the interface states thereby altering the low field conduction region.
“q-hat” and jet quenching

Abstract We discuss bremsstrahlung rates for a weakly coupled fast jet propagating in dense nuclear matter. A time-dependent radiation rate which smoothly merges with previous limits is introduced, exhibiting a clear transition between two regimes after a traversed length of order one to several fermis. The different physical processes probed in the two regimes are discussed.
Cytokine and growth factor immunohistochemical spinal profiles in two animal models of mononeuropathy

Nerve injury leads to central neuroimmunologic responses that may be integral to the development and maintenance of chronic neuropathic pain in humans. Recent data have demonstrated that cytokines and growth factors may be strongly implicated in the generation of pain states at both peripheral and central nervous system sites. We utilized immunohistochemical methods to investigate this phenomenon in rat models of neuropathic pain. Specifically, we employed well-characterized models of neuropathy that result in behaviors suggestive of neuropathic pain in humans; a freeze lesion of the sciatic nerve, termed sciatic cryoneurolysis, and a chronic constriction sciatic nerve injury. We used immunohistochemistry to examine spinal localization of the cytokines, interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha) and the growth factors, basic fibroblast growth factor (bFGF), and transforming growth factor-beta1 (TGF-beta) at 3, 14, and 35 days following sciatic cryoneurolysis or 6 days following chronic constriction injury as compared with normal, unoperated rats. There was minimal, diffuse cytokine/growth factor staining in lumbar spinal tissue from the normal group. However, cell profile quantification demonstrated increases in lumbar spinal IL-1beta-, TNF-alpha- and TGF-beta-like immunoreactivity (LI) in both mononeuropathy models studied. At 3 days following sciatic cryoneurolysis, intense bFGF LI was present in the ipsilateral dorsal and ventral horn. By 14 days bFGF LI was also observed in contralateral dorsal and ventral horns. In contrast, we found no obvious staining differences in lumbar spinal cord following the chronic constriction injury. This study demonstrated increased specific cytokine and growth factor-like expression in the spinal cord following peripheral nerve injuries. It also showed a differential expression of bFGF in two distinct mononeuropathy models. These results provide further evidence that central cytokine production via a neuroimmune cascade may be involved in the development and maintenance of behaviors that mimic neuropathic pain following nerve injury.
Pathogenesis of Hodgkin's disease.

Abstract A hypothesis, based on clinical and laboratory observations, relates viral infection and host immunity to the pathogenesis of Hodgkin's disease. In this hypothesis T cells (thymus- derived lymphocytes) during viral infection undergo antigenic alteration of their surface while normal immunocompetent T cells within the same lymphoid organ react against the antigenically altered cells. A chronic immune reaction (similar to graft-versus-host disease) then leads to the appearance of the neoplastic reticulum cells. The hypothesis is compatible with each of the salient clinical features of Hodgkin's disease, including primary site of the disease, histological pattern, preclinical status, loss of cell-mediated immunity, and prognosis.
Increased motor excitability produced by alerting stimuli.

Abstract The proposal that increased excitability of sensory and motor systems occurs in response to dishabituated sensory stimuli was supported by experiments with cats in which excitability was measured by the amplitude of the response evoked by an electrical test stimulus. Evoked EMG, evoked head movement and the postsynaptic visual cortex response were briefly augmented following such stimuli, with a latency less than 20 msec for auditory and less than 50 msec for visual stimuli. Evoked EMG responses were rare during habituation, but even faint stimuli (40 db (SPL) tone pips) were effective during conditioning procedures. The proposed organization of the brain was thought to have adaptive significance, helping the subject to cope with emergency situations by enhancing the processing of sensory and motor information.
Wilkerson on Natural Kinds

While I certainly do not intend to discourage the drawing of inspiration from the works of Aristotle, when one's aim is to illuminate the practice and metaphysics of contemporary science such inspiration must surely be tempered by a passing acquaintance with the deliverances of, say, the last hundred years of scientific inquiry. T. E. Wilkerson's paper, 'Natural Kinds' {Philosophy 63 (1988) 29-42) falls regrettably short of this desideratum. Wilkerson makes a number of points about sortal terms, and proposes a number of distinctions between types of such terms. Much of this seems useful and unobjectionable. My concern here is solely with what he considers to be natural kinds and natural kind terms. Wilkerson's primary concern is with the question what it is to be a natural kind. He does not appear to see any difficulty about the question what are instances of natural kinds. The main point of this note is to claim that if Wilkerson's conception of what it is to be a natural kind is correct, then they are much harder to find than he seems to think. As to the first question, Wilkerson considers a natural kind to be a kind characterized by a real essence, and also one that provides a suitable subject for scientific investigation (p. 29). Presumably this scientific investigation will deliver 'precise' laws, since this is what is said to be impossible for non-natural kinds such as nations and banknotes (p. 30). Finally, and consequently, natural kind predicates are inductively projectible: 'If I know that a lump of stuff is gold, or that the object in front of me is an oak, I am in a position to know what it is likely to do next, and what other things of the same kind are likely to do' (p. 30).
A comment on «a method to measure the duration of DNA synthesis and the potential doubling time from a single sample»

Recently a method was introduced by Begg et al. (Cytometry 6:620–626, 1985) for the calculation of the DNA synthesis time, TS using flow cytometry to monitor the progression of cells that have been pulse-labeled by bromodeoxyuridine (BrdUrd). Ideally, the method uses only a single two-parameter histogram of the progressed cells to obtain TS. The essence of the method is to be able to obtain an initial point from general principles, draw a line through it and the measured point, and extrapolate to a level of progression that would be attained when the time is equal to TS. In this comment, explicit values are derived for the initial point and the progression of cells based on kinetic arguments, and a new method is presented for estimating TS. This new method is compared to earlier methods, and the effects of a finite labeling time and variation in the transit times are considered. Finally, an equation is developed for estimating TS following multiple measurements.
“Inert” Components of Pharmaceutical Preparations

AbstractA discussion of the role of excipients in pharmaceutical formulation including an analysis of regulatory requirements in the United States and other countries as well as a description of recent efforts to develop concise, accurate and practical compilations of technical information of these substances.
Chemical reactions with upright monolayers of cruciform π-systems

The study below details the synthesis and self-assembly of new cruciform π-systems and their in situ chemical reactions in monolayer films. Analysis of the packing in the crystal structure of one of these unusually shaped molecules reveals that the terphenyl arm, which is twisted out of conjugation, makes edge-to-face contact with neighboring molecules aligning the conjugated bisoxazole arms in rows. In self-assembled monolayers on metal surfaces, these cruciform π-systems present reactive groups at the film/air interface. Films that present aldehyde functionality react with aromatic anilines to give surface-bound imines. Dimers that are >4.5 nm in length and contain a conjugated imine linkage can be made in situ on gold substrates through this strategy.
Play Pays: Urban Land Politics and Playgrounds in the United States, 1900-1930

Existing literature on the explosion of playgrounds at the beginning of the twentieth century focuses on the theories and self descriptions of the leadership of the playground movement, particularl...
Tracer diffusion of crown ethers in cyclohexane

Abstract Tracer diffusion coefficients in cyclohexane of s -trioxane, 12-crown-4, 15-crown-5, 18-crown-6, dicyclohexano-18-crown-6, and dicyclohexano-24-crown-8 have been measured with the Taylor dispersion technique from 298 to 358K. It is demonstrated that the deviation from the Stokes-Einstein relationship is explicable with a microfriction factor which accounts for the solute-solvent size discrepancy; the non-spherical nature of crown ethers is averaged out by rapid molecular rotation. As a result, the measured diffusivities are successfully interpreted with a rough-hard-sphere theory of molecular diffusion. The Arrhenius equation and Hildebrand's free-volume model are also capable of correlating quite well the experimental results reported here.
The Dynamism of Mexican Exports: Lost in (Chinese) Translation?

Summary This paper analyzes the extent to which Mexican exports have penetrated US markets in recent years, and juxtaposes such an analysis with the performance of China. We find that Mexico’s main non-oil exports are losing dynamism, and their relative share in the US market is either declining or growing slower than China’s. This trend is a new one, and begins after China’s entry into the WTO. A number of factors could explain these findings. These include: (i) the real appreciation of the real exchange rate of the peso relative to the US dollar combined with the trend toward undervaluation of the Chinese currency, (ii) the decline of public investment in Mexico, especially in infrastructure, (iii) limited access to bank credit in Mexico, and (iv) the absence of government policy in Mexico to help spur technological innovation and to strengthening its domestic backward and forward linkages.
Factors affecting protein synthesis in Hymenolepis diminuta (Cestoda).

Abstract 1. 1. The cestode, Hymenolepis diminuta , incorporated C 14 -labeled amino acids from the ambient medium into protein. The amino acids tested were incorporated at rates which did not correspond directly to the apparent internal concentration of the amino acid. The incorporation rate of lysine-C 14 was linear during a 2-hr incubation period. 2. 2. Starvation produced a depression in the corporation of lysine-C 14 . Preincubation of starved worms in glucose slightly stimulated the incorporation whereas 3-0-methylglucose produced no stimulation. 3. 3. The presence of CO 2 caused a marked stimulation of lysine-C 14 incorporation in both starved and unstarved worms. The presence of glucose in the preincubation medium further enhanced this stimulation in starved worms. 4. 4. Incubation with 2,4-dinitrophenol inhibited the incorporation of lysine-C 14 by per cent. DNP abolished the stimulatory effects of CO 2 and glucose on lysine-C 14 incorporation in starved worms, substantiating the central role of CO 2 in energy metabolism of the worm. 5. 5. Galactose stimulated lysine-C 14 incorporation, but was not as effective as glucose. 6. 6. The significance of CO 2 and glucose in the metabolism of the parasite is discussed.