cssi/SciSciGPT-SciSciNet huggingface dataset:
Synthesis and characterization of conjugates of poly(α-amino acids) and manganese (III) protoporphyrin IX as relaxation enhancement agents for MRI†

Polymers are finding increasing use in medicine, and conjugates of paramagnetic species and polymers are now being studied as relaxation enhancement agents to improve contrast in magnetic resonance imaging. To assess the potential of such agents, the enhancement of proton relaxation by paramagnetic species bound to macromolecules has been observed for four conjugates of amino acid polymers and manganese (III) protoporphyrin IX. The conjugates all differ in their abilities to enhance the relaxation of water protons in solution; values of relaxation rates range from 3.2 to 9.1 s−1 mM−1. The rotational correlation times and volumes of the kinetic units within the macromolecules have been determined by fluorescence depolarization in an effort to understand the range of relaxation rates observed for the conjugates. The metalloporphyrins bound to the polymers all have very similar dynamic characteristics.
Self-preservation in Early Eighteenth-Century London

AbstractThe idea of self-preservation has long been examined in intellectual histories of the early modern period. This article relates the history of the idea to the history of London in the early eighteenth century. It traces the formation of a language of self-preservation within three bodies of urban texts: the Ordinary's accounts of criminals condemned to death at Tyburn, discussions of maidservants, and descriptions of the masquerades. In each of these literatures, a worldly discourse of self-preservation posed a challenge to prevailing moralities. Hence, notions of suspicion, avoidance, self-advancement, reinvention and verbal sophistication created tension in a society invested in charity, trust, obedience, submissiveness, and modesty. By tracing this development, this article identifies a culture of enlightenment emerging from the intellectually productive milieu of urban modernity.
An epidemiologic study of neural tube defects in Los Angeles County II. Etiologic factors in an area with low prevalence at birth

Epidemiologic characteristics of neural tube defect (NTD) births occurring in Los Angeles County, California, residents during the period 1966-1972 are presented. The prevalence at birth was 0.52/1000 births for anencephalus, 0.51/1000 for spina bifida, and 0.08/1000 for encephalocele, rates considered to be low for a predominantly white population. We hypothesized that environmental (nongenetic) factors are of less etiologic importance in a low-prevalence population than in areas or time periods with high prevalence. We tested that hypothesis by examining epidemiologic characteristics of NTDs in Los Angeles County and comparing them with high-prevalence populations. The data did not support a major etiologic role for environmental factors: (1) no significant differences between rates by month of birth or conception; (2) no significant association with maternal age or parity for anencephalus; for spina bifida a significant maternal age effect (P less than 0.01) and for encephalocele a parity effect (P less than 0.02); and (3) no significant relationship with father's occupational class for either anencephalus or encephalocele but a marginally significant (P less than 0.05) inverse association for spina bifida when a statistic based on ordinal relationships was used. Findings supporting the importance of genetic factors in etiology included: (1) a high percentage of males; (2) a higher twin concordance rate than in high-prevalence populations; and (3) an anencephalus rate among blacks comparable with rates for blacks in other United States populations. Our findings in conjunction with those from other areas and times of low prevalence suggest environmental factors play a relatively insignificant role in the etiology of NTDs in such populations.
A study of small aftershocks of the Oroville California, earthquake sequence of August 1975

Abstract The August 1, 1975 earthquake near Oroville, California, occurred along the Sierra foothills in a region characterized by occasional moderate earthquakes. Several earthquakes in the general region, including those in 1869, 1875, and 1909, appear to have had significant aftershock sequences. The general character of the aftershock sequence of the Oroville earthquake thus does not appear to be anomalous when measured against the known seismic history of this area. Four smoked-paper micro-earthquake recorders were deployed immediately following the occurrence of the main earthquake to attempt to define the structural associations of the principal earthquake by location and analysis of aftershocks. Focal locations for 243 micro-earthquakes in the magnitude range of 1–3 were selected from the 30-day period (August 2–September 1), during which monitoring was continued. The aftershocks clearly define a planar surface striking north–south and dipping west at 62° from the surface to a depth of about 12 km. Aftershocks during the first two days of monitoring defined a surface of active faulting of approximately 100 km 2 . Extension of this surface both to the north and south began on August 5 at focal depths of 5–10 km, resulting in a total ruptured area of approximately 125 km 2 . The number of aftershocks per day decreased at the rate of t −1.1 , but the decay curve was punctuated by several secondary aftershock sequences. No. direct relationship between the aftershock sequence and the presence of Oroville Reservoir was observed.
The effect of a de-oiling mechanism on the production of high quality vacuum fried potato chips

Abstract Ways of removing the adhered surface oil, while the product is still in the fryer, has been the subject of many studies and patents for deep-fat frying processes. In the case of vacuum frying, this problem is exacerbated by the pressurization step, which causes a quick increase in pressure in the pore space thus forcing most of the surface oil into the product pore spaces. Therefore, for vacuum frying, a de-oiling mechanism is required to reduce the excessive oil absorption at the surface of the product. The main objective of this study was to establish the effect of de-oiling and frying temperature on potato chips quality attributes and oil absorption. Potato slices (30 g, 1.6 mm thick, 5 cm diameter) were fried for 360 s in a lab-scale vacuum fryer (P Samples fried at 120 °C for 360 s (non-centrifuged) had a final oil content of 0.43 g/g product compared to 0.097 g/g product for the centrifuged ones. Most of the oil was absorbed in the product during first 180 s of frying; and by the end of frying only 14% of the total oil content (TOC) was internal oil (IOC) while 86% was surface oil (SOC). About 34% of the IOC and only 0.7% of the SOC was absorbed during the first 20 s of frying. Oil content absorption kinetics increased exponentially during the first 120 s of frying followed by a slight drop until the end of frying. At the end of frying, bulk density and porosity values of the non-centrifuged samples were around 800 kg/m3 and 0.36 and 564 kg/m3 and 0.61 for the centrifuged samples, respectively. No significant changes (P Experimental data for color and oil distribution with temperature can be accurately predicted using a special case of the logistic model. The kinetics of oil distribution and porosity with temperature can be described using the fractional conversion exponential model. Vacuum frying with a de-oiling step produces superior quality fried products with lower oil content.
Effect of inhibitory amino acid antagonists on IPSPs induced in lumbar motoneurons upon stimulation of the nucleus reticularis gigantocellularis during active sleep

Abstract The present study was performed to generate data implicating glycine or γ-aminobutyric acid as neurotransmitter candidates mediating the IPSPs which are recorded in lumbar motoneurons following electrical stimulation of the nucleus reticularis gigantocellularis (NRGc) during the atonia of active sleep. Accordingly, intracellular records were obtained from lumbar motoneurons in unanesthetized, normally respiring cats during naturally occurring states of active sleep, while inhibitory amino acid antagonists were microiontophoretically released next to the recorded cell. Electrical stimuli, applied to the NRGc during active sleep under drug-free conditions, evoked inhibitory postsynaptic potentials (IPSPs) in all of the lumbar motoneurons which were examined. These NRGc-induced IPSPs exhibited an average latency-to-onset of 26.6 ± 1.3 ms, a latency-to-peak of 42.5 ± 1.3 ms, an average amplitude of 3.9 ± 0.4 mV and a duration of 34.4 ± 2.1 ms. Strychnine, when applied microiontophoretically, abolished or markedly suppressed these NRGc-induced IPSPs. In contrast, the microiontophoretic application of picrotoxin or bicuculline methiodide failed to block these IPSPs. To the extent that strychnine may be considered to be a specific antagonist of glycine, the present results suggest that glycine (or a structurally related amino acid) participates in the generation of NRGc-induced IPSPs during the atonia of active sleep.
A deficiency in the B cell response of C57BL/6 mice correlates with loss of macrophage-mediated killing of Leishmania amazonensis

Infection of C3HeB/FeJ and C57BL/6 mice with Leishmania major stimulates a healing cell-mediated immune response, while Leishmania amazonensis infection leads to chronic disease. Here we show C3HeB/FeJ mice co-infected with both species of Leishmania heal, while co-infected C57BL/6 mice do not. Using an in vitro killing assay we determined B cells from infected C57BL/6 mice are ineffective in promoting parasite killing compared with B cells from infected C3HeB/FeJ mice. Furthermore, infected C57BL/6 mice produce less antigen-specific antibodies compared with infected C3HeB/FeJ mice. These findings suggest B cells play a required role in the cell-mediated immune response against L. amazonensis.
The evolution of the resistance of aluminum interconnects during electromigration

Abstract Resistance monitoring is a traditional method to investigate electromigration failure. It is important to understand how much information can be extracted from the data generated by these experiments. To this end, precision resistance measurements were included as part of accelerated electromigration tests performed inside of a high voltage scanning electron microscope (HVSEM). Twenty-two passivated Al interconnects were tested at 30 mA/μm 2 and at two temperatures, half at 212°C and half at 269°C. During every test, our automated apparatus stored images of each 300 μm long structure several times per hour. The resistance of each line was also precisely measured and recorded. Changing the temperature affected only the time scale of the resistance evolution. There were resistance changes before voids formed that were neither due to temperature fluctuations nor solute effects. In most cases, the nucleation of the first void to form in a line was signaled by an increase in the time derivative of the resistance. Due to the strong effect of void shape, the void volume could not be determined by the magnitude of the resistance change. The width of a void (transverse to the line) rather than the volume largely determined the resistance change.
Parametric harmonic-to-fundamental ratio contrast echocardiography: a novel approach to identification and accurate measurement of left ventricular area under variable levels of ultrasound signal attenuation.

Objectives We introduced a harmonic-to-fundamental ratio (HFR) of the radiofrequency (RF) signals that reduces confounding effects of attenuation. We studied whether HFR analysis of RF signals received from contrast microbubbles allows accurate measurement of the left ventricular (LV) cavity area under varying levels of attenuation.
Stability regions in the parameter space for a unified PID controller

In this paper a unified approach is presented for finding the stability boundary and the number of unstable poles for an arbitrary order transfer function with time delay in continuous-time or discrete-time systems. These problems can be solved by finding all achievable proportional integral derivative (PID) controllers that stabilize the closed-loop polynomial of a single-input single-output (SISO) linear time invariant (LTI) system. This method is used to predict the number of unstable poles of the closed-loop system in any region of the parameter space of a PID controller. The delta operator is used to describe the controllers because it provides not only numerical properties superior to the discrete-time shift operator, but also converges to the continuous-time case as the sampling period approaches zero. A key advantage of this approach is that the stability boundary can be found when only the frequency response and not the parameters of the plant transfer function are known. A unified approach allows us to use the same procedure for finding the continuous-time or discrete-time stability region and the number of unstable poles of the system. If the plant transfer function is known, the stability regions can be found analytically.
Geoelectric Sounding for Delineating Ground-Water Contamination

A resistivity survey was made in the vicinity of a landfill in a glacial aquifer to determine the extent of ground-water contamination. The survey consisted of 12 electrical soundings with the Winner probe configuration. An examination of the sounding curves and logs of nearby test borings suggested a three-layer geoelectric model for studying water quality variations. The thicknesses and the resistivities of the upper two layers were fixed. Differences in apparent resistivity were assumed to be due only to differences in specific conductance of ground water in the saturated zone (third-layer resistivities). Apparent resistivities at the largest probe spacing, 102 feet (31 m), were then computed for a range of assumed third-layer resistivities. Specific conductances corresponding to third-layer resistivities were then computed using an assumed formation factor of 4.5. A relation between apparent resistivity at the 102-foot spacing and specific conductance was developed for converting apparent resistivities to specific conductances. Quadratic trend surfaces developed for specific conductances measured at monitoring wells and computed from apparent resistivity are shown to be in good agreement. Under favorable conditions, interpretation of electrical sounding curves provides a basis for estimating specific conductance of ground water from surface resistivity methods. This leads to a quantitative assessment of ground-water contamination which compares favorably with that determined from monitoring wells.
Interaction of Ca2+ with cardiolipin-containing liposomes and its inhibition by adriamycin

The interaction of cardiolipin-containing, unilamellar liposomes with Ca2+ was assessed by flow dialysis in the presence of 2–100 μM 45Ca2+, using vesicles formed from phosphatidylcholine (PC) and from PC and cardiolipin in mole ratios from 16:1 to 1:1. Control (PC only) vesicles bound no detectable Ca2+. In contrast, Ca2+ binding to cardiolipin-containing vesicles was substantial and dependent on vesicle concentration. Scatchard plots for the binding were concave upward. Resolution of the data, assuming the presence of two independent classes of binding sites, indicated a high-affinity site with apparent kD = 5.57 ± 0.48 μM (S.D.) and a second site with KD in the millimolar range. Interaction of cardiolipin-containing liposomes with Ca2+ was insensitive to monovalent cations (Na+, K+, Rb+), but was inhibited by ruthenium red ⪢ La3+ > Mn2+ > Mg2+. Progressive increases in the PC: cardiolipin ratio markedly increased the apparent KD for Ca2+ at the high-affinity site. Stoichiometry of Ca2+ binding at the site passed through a maximum at a PC: cardiolipin ratio of 4:1. The potent antineoplastic agent adriamycin also inhibited the interaction of Ca2+ with cardiolipin-containing liposomes in a dose-dependent manner; effects were detected at 10 μuM antibiotic. Unlike PC, adriamycin altered the Stoichiometry of the high-affinity interaction but not the apparent kD. Adriamycin effects increased with pH in the range of the pKA of its amino group. These results suggest that inhibition by adriamycin may result from a mechanism other than simple competition for the charged head group of cardiolipin.
How Time Flies

From the earliest antiquity and right throughout the Middle Ages up to our own times, people of all degrees of sophistication have regarded it as one of the most central features of existence that time moves, so that events are carried from the future toward us and then recede further and further into the past. Thus we hear Job complaining 'My days are swifter than a weaver's shuttle', Chaucer declaring 'Ay fleets the time it will no man abide', and Sir Walter Scott observing that 'Time rolls his ceaseless course\ Yet the majority of analytic philosophers today hold with Russell that the transient view of time is hopelessly flawed and have characterized all attributions to time of such properties as flying, passing or rolling on, whether swiftly or relentlessly, as involving very misleading metaphors, since in actual reality all events and moments stay forever fixed in the position where they occur. There is no such entity as the moving NOW, time remains still and all temporal relations are permanent. This remarkable situation I should venture to suggest is due to a number of factors. First of all Russell's suggestion as to how we can achieve great ontological economy by eliminating all reference to any transient feature of time and still be able to say about our temporal experiences most of the things we want to say, is singularly ingenious. Secondly, the physical sciences whose prestige has been very high in this century seem to provide support to RusselPs position. In books on physics, chemistry or astronomy, we usually do not find what McTaggart called A-statements, e.g. 'E is in the future' or 'E is in the past" (except perhaps in the Preface). There are of course indefinitely many natural processes that are functionally related to time, yet they can all fully be described by only using so-called B-statements, statements like <E1 is before (or after or simultaneous with) E2'. Thirdly, the Russellian view has been vigorously defended by some of the most outstanding philosophers of this century. And finally, for some reason the
Porcine muscle glycogen structure and its association with other muscle properties.

SummaryThe average chain length of glycogen from porcine muscles decreased by approximately one glucose residue during post-mortem glycolysis. There was however, a more severe decrease in both external and internal chain lengths of the glycogen from the Chester White muscles which had a slow rate of anaerobic glycolysis. Sucrose feeding tended to lengthen both the external and internal chain lengths of the muscle glycogen and accelerated the rate of anaerobic glycolysis. These findings suggest that glycogen structure may be altered by nutritional as well as genetic influences and, in both instances, may influence the rate at which the molecule is degraded.
Exclusive Greenery: new gated communities in Cairo

This paper examines the construction and marketing of recent upscale gated communities on the Egyptian capital's desert outskirts. Discussing questions of design and their use in promotional materials, I show how global inventories of architecture and social lifestyles are inserted in concrete local marketing contexts. While some of this marketing and subsequently some communities are successful, I argue that many aspects of projects are flawed in their neglect of local social forms and material demands. Differentiating between projects that imply a certain globalization of the local versus those that represent the localization of the abstractly global, I argue that the latter are more likely to fail. Reviewing a number or recent projects I illustrate how they all address upscale material demands, social sentiments and fear, and centrally promise safe and healthy homes and like-minded neighbors. Drawing on recent western theoretical debates about the increasing segregation of urban spaces, and the disappearance of public spaces, this paper explores the use and limits of such theorizations for the context of a post-colonial Middle Eastern metropolis.
Topological X-rays revisited

We continue our study of topological X-rays begun in Lynch [Topological X-rays and MRI's, iJMEST 33(3) (2002), pp. 389�392]. We modify our definition of a topological magnetic resonance imaging and give an affirmative answer to the question posed there: Can we identify a closed set in a box by defining X-rays to probe the interior and without looking inside the box?
Effect of Hypertension on Aortic Root Size and Prevalence of Aortic Regurgitation

Although early reports suggested that hypertension predisposed to aortic root enlargement and consequent aortic regurgitation, more recent pathological and M-mode echocardiographic studies have not found an association between hypertension and aortic enlargement when age is considered. These discrepancies may partially reflect methodological shortcomings in the accuracy and reproducibility of aortic and blood pressure measurements. Therefore, we measured two-dimensional echocardiographic diameters of the aortic root at four locations and compared findings with ambulatory and resting blood pressures and measures of body size in 110 normotensive and 110 hypertensive men and women matched for age and sex. Aortic diameters at the anulus (2.41 +/- 0.29 versus 2.34 +/- 0.24 cm, P = .06) and sinuses (3.47 +/- 0.44 versus 3.37 +/- 0.36 cm, P = .08) were marginally higher, whereas diameters at the supra-aortic ridge (2.94 +/- 0-38 versus 2.81 +/- 0.32 cm, P < .01) and ascending aorta (3.26 +/- 0.45 versus 3.11 +/- 0.32 cm, P < .01) were significantly increased in hypertensive subjects. Aortic diameters increased with increasing quartiles of diastolic and systolic pressures, particularly at the supra-aortic ridge and ascending aorta. In multivariate analyses, blood pressure remained an independent determinant of distal aortic diameters after body size and age were considered. Aortic regurgitation was seen in 5 normotensive and 7 hypertensive subjects and did not differ in severity. Thus, hypertension is associated with a slight increase in aortic root size, most notably of the supra-aortic ridge and proximal ascending aorta. Although dilatation at the commissural attachment might be expected to predispose to an increase in aortic regurgitation, we did not detect such a difference in this population of healthy, asymptomatic individuals.
Detecting Emergent Terrorism Events: Finding Needles in Information Haystacks

Terrorist groups tend to develop unconventional ways to disrupt or destroy economic and critical infrastructures. Examples of unconventional methods include setting up cyberattack cells to disrupt critical infrastructures, using unmonitored financial resources to disrupt or bankrupt national economies, and establishing organizations within countries to desensitize the population to terrorist objectives. Sometimes there are patterns, but most often there are no obvious patterns. This presentation addresses the detection of emergent terrorist events by finding critical pieces of information buried in large volumes of data spanning many disparate data sources.
Polymerizability, copolymerizability, and properties of cyanoacrylate-telechelic polyisobutylenes II: copolymerization of three-arm star cyanoacrylate- telechelic polyisobutylene with ethyl cyanoacrylate†

This research concerned the synthesis and characterization of novel conetworks containing polyisobutylene (PIB) and polyethyl-2-cyanoacrylate [poly(Et-CA)] sequences. The syntheses involved the copolymerization of CA-telechelic three-arm star PIB [O(PIB-CA)3] with ethyl-2-cyanoacrylate (Et-CA) mediated by nucleophiles or by living tissue (fresh eggs). The conetworks were characterized by swelling in hexanes, tetrahydrofuran (THF), and acetone, and the results indicate co-continuous PIB and poly(Et-CA) domains. The conetworks exhibit two Tgs indicating phase-separation between PIB and poly(Et-CA). The outstanding oxidative resistance of the conetworks was demonstrated by exposure to concentrated nitric acid. The tensile strengths, moduli, and elongations of a series of conetworks with different overall compositions were investigated and the findings interpreted in terms of covalently linked rubbery and glassy domains. AFM also suggests the presence of phase-separated rubbery and glassy domains. DMTA spectra of a O(PIB-CA)3 homonetwork, and O(PIB-CA)3/Et-CA conetworks were analyzed and interpreted in terms of coexisting rubbery and glassy domains. Observations made during the exposure of O(PIB-CA)3/Et-CA mixtures to proteinaceous tissue, in combination with characterization data, were used to propose a structural model for the conetworks. Copyright © 2007 John Wiley & Sons, Ltd.
In-situ X-ray absorption spectroscopy study of Pt and Ru chemistry during methanol electrooxidation.

Methanol electrooxidation in a 0.5 M sulfuric acid electrolyte containing 1.0 M CH3OH was studied on 30% Pt/carbon and 30% PtRu/carbon (Pt/Ru = 1:1) catalysts using X-ray absorption spectroscopy (XAS). Absorption by Pt and Ru was measured at constant photon energy in the near edge region during linear potential sweeps of 10−50 mV/s between 0.01 and 1.36 V vs rhe. The absorption results were used to follow Pt and Ru oxidation and reduction under transient conditions as well as to monitor Ru dissolution. Both catalysts exhibited higher activity for methanol oxidation at high potential following multiple potential cycles. Correlation of XAS data with the potential sweeps indicates that Pt catalysts lose activity at high potentials due to Pt oxidation. The addition of Ru to Pt accelerates the rate of methanol oxidation at all potentials. Ru is more readily oxidized than Pt, but unlike Pt, its oxidation does not result in a decrease in catalytic activity. PtRu/carbon catalysts underwent significant changes dur...
Repeat Tragedy: Rampage Shootings in American High School and College Settings, 2002-2008

The authors examine rampage shootings in American high schools after 2002 and consider whether factors identified in their prior research on rampages from 1974 to 2002 account for the more recent cases. The authors find that the five factors—social marginality, individual predisposing factors, cultural scripts, failure of the surveillance system, and availability of guns—remain important features. The authors then contrast these high school shootings with the recent spate of college rampage shootings that resemble the high school cases in some ways but differ in others. College shooters are older and therefore typically further along in the development of serious mental illness.
Consumption of ground bison does not increase early atherosclerosis development in hypercholesterolemic hamsters

Abstract The present study investigated the effect of substituting the source of dietary protein in a hypercholesterolemic animal model. Sixty male Golden Syrian hamsters approximately 10 weeks of age were placed on a chow diet for one week. The hamsters were then divided into one of four groups, 15 hamsters per group, based on similar mean plasma cholesterol concentrations and fed a semipurified, hypercholesterolemic diet containing 20% by weight of either soy protein, casein, lyophilized ground bison, or lyophilized ground beef and 0.05% cholesterol for 8 weeks. After 8 weeks of dietary treatment, the soy protein group had significantly lower plasma total cholesterol (TC), nonHDL-C (very low- and low-density lipoprotein cholesterol), and HDL-C (high-density lipoprotein cholesterol) concentrations compared to the casein (−20, −23, and −18%; respectively), bison (−24, −32, and −19%; respectively), and beef (−34, −41, and −30%; respectively). The bison and casein groups had significantly lower plasma TC (−14 and −18%, respectively), nonHDL-C (−14% and −23%, respectively), and HDL-C (−14 and −15%, respectively) concentrations compared to the beef. The soy protein, bison, and casein groups had significantly lower plasma triglycerides (TG) concentrations compared to the beef (−49, −25, and −37%; respectively). Unexpectedly the bison and beef groups had significantly reduced early atherosclerosis compared to the soy protein (−50 and −43%, respectively) and casein (−68 and −64%, respectively). The soy protein group also had significantly reduced early atherosclerosis compared to the casein (−37%). In conclusion, plasma nonHDL-C may not be a good indicator of the development of early atherosclerosis in the hamster model and that the reduced early aortic atherosclerosis in the bison fed hamsters may be due in part to both the lipid and protein composition of the bison.
Apomorphine-haloperidol interactions: different types of antagonism in cortical and subcortical brain regions.

Abstract Apomorphine, a dopamine (DA) receptor stimulant induced a dose-dependent decrease in the content of the dopamine metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the olfactory tubercle and striatum of rats, but it was ineffective in the frontal cortex. Apomorphine also antagonized the haloperidol-induced accumulation of DOPAC and HVA in the olfactory tubercle and striatum, whereas in the frontal cortex it antagonized the effects of haloperidol on DOPAC but not on HVA. The total (free and conjugated) content of DA metabolites was measured in these experiments.
Vocal tract adjustments for the projected voice

Summary These preliminary findings are for one subject only and therefore do not allow any inferences to be made for general differences between the ring and constricted vocal tract configurations. In this one case, the training goal of an open throat was confirmed by radiography, and the associated sound production was judged louder in a listening test. Whether any perceived difference in loudness is due to the vocal tract shape cannot be determined until the acoustic analysis is made and correlated to the physiological features. Then it may be possible to determine if an effect on resonance, such as tuning, can account for the difference in loudness or if the difference is due to the source function.
The rotational barrier of an enaminonitrile. Charge and energy redistribution during rotation about the C-N bond

Ab initio quantum mechanical techniques were used together with PROAIM electron density partitioning and CHELPG electrostatic potential analysis to examine the charge density distribution of model enaminonitrile1 in its planar ground state and in its two rotational transition states. The barrier to rotation about the C-N bond was calculated to be 15.4 and 15.6 kcal/mole for the two rotational transition states at the HF/6-31G** level of theory, and was found to originate from a redistribution of electronic kinetic energy between the amino group and the rest of the molecule in a manner similar to that found for formamide and sulfonamide. Similarly, the C-N bond length and amino group electron population were found to depend upon the C-N torsional angle. Electrostatically derived atomic point charges were also examined at each stationary point using the CHELPG program. CHELPG electrostatic potential results were found to represent the traditional “external” viewpoint of the charge density consistent with a resonance model, while the results from PROAIM calculations were found to describe the underlying charge density and kinetic energy density redistribution responsible for the rotational barrier.
Constitutive synthesis of the GAL4 protein, a galactose pathway regulator in saccharomyces cerevisiae

Abstract We have demonstrated that induction of synthesis of the mRNAs encoding the galactose-catabolizing enzymes galactokinase (E.C.2.7.1.6) and transferase (E.C.2.7.7.12) occurs in Saccharomyces cerevisiae following the addition of α-D-galactose during continuous exposure to 100 μg/ml of cycloheximide. The prompt induction and sustained accumulation of galactose message activity (detected in the wheat germ in vitro translation system) following the cessation of all detectable protein synthesis in vivo indicate that the GAL4 regulatory protein and any as yet undefined positive effectors of transcription of the galactose genes exist prior to induction and are therefore synthesized constitutively. We have carried out synchronous matings in which inducible gal1 cells lacking galactokinase function were mated with uninducible gal4 cells containing either the normal GAL80 -encoded galactose-sensitive repressor or a dominant GAL80 S -encoded galactose-insensitive repressor. All cells were cultured in the continuous presence of galactose to allow for the possibility of inducible synthesis of the GAL4 -specified protein. Galactokinase was expressed in the GAL80/GAL80 zygote (the control experiment) and not in the GAL80 S / GAL80 zygote, indicating that a galactose-insensitive repressor can neutralize already existing GAL4 protein activity. These results, particularly the cycloheximide finding, necessitate a revision of a central element of the Douglas and Hawthorne (1966) model for galactose regulation, in which it was postulated that the GAL80 gene product acts at a GAL4 operator to repress GAL4 transcription. Our observations indicate that the repressor must control GAL4 regulatory activity at a post-translational level.
Radiographic analysis of Haglund's deformity: an evaluation of NCSP and RCSP.

Biomechanics is an important topic in considering podiatric foot and ankle pathology. It is the root of all underlying factors during the diagnosis of a structural foot deformity. One such deformity is an enlargement of the posterosuperior aspect of the calcaneus, called a Haglund’s deformity. Structural malposition of the foot, including rearfoot equinus, compensated rearfoot varus, compensated forefoot valgus, plantarflexed first ray, and a cavus foot have all been associated with producing retrocalcaneal discomfort.1 These biomechanical conditions have been well documented, with lateral x-ray evaluation in the sagittal plane, of producing a Haglund’s deformity.1 However, additional areas in biomechanics can still be investigated to understand the development of a Haglund’s deformity.
A Scientific Reading of Levinas’ Response to Heidegger: The Redemptive Edge of Time

Abstract In responding to Martin Heidegger, Emmanuel Levinas characterized time as revelatory and redemptive. For Levinas, Heideggerian being was self-contained and self-identical, and therefore unable to generate the sense of novel possibility which occasions the fleeting present. Something similar to Heideggerian Being may be said to have taken hold in the nineteenth century with the development of thermodynamics. The second law of thermodynamics was portrayed as the “arrow of time” moving inevitably toward universal heat death—cosmic stasis or self-identity. I argue that modern physical science itself does not fully validate this portrayal. There are, at the metaphysical level, explanatory gaps or openings which suggest other, more hopeful possibilities. These openings, I submit, are analogous to the ruptures of otherness which Levinas identified with the generosity of being and time’s redemptive aspect.
Electrocatalytic O2 reduction at glassy carbon electrodes modified with dendrimer-encapsulated Pt nanoparticles

Platinum dendrimer-encapsulated nanoparticles (DENs) were prepared within fourth-generation, hydroxyl-terminated, poly(amidoamine) dendrimers and immobilized on glassy carbon electrodes using an electrochemical coupling strategy. X-ray photoelectron spectroscopy, electron microscopy, and electrochemical experiments confirmed that the Pt DENs were about 1.4 nm in diameter and that they remained within the dendrimer following surface immobilization. The resulting Pt DEN films were electrocatalytically active for the oxygen reduction reaction. The films were also robust, surviving up to 50 consecutive cyclic voltammograms and sonication.
13C NMR chemical shifts of methyl cation and anion: A relationship between chemical shift and charge?

Abstract The chemical shifts of methyl cation and anion have been calculated. The tensor components about the out-of-plane p orbitals were essentially the same, but the components about the in-plane axes differed by over 700 ppm. The experimental chemical shifts of benzene and the aromatic ions fall on the line connecting the shifts and charges of the methyl ions. These data are correlated by a simple model, that also accounts for the large downfield shifts found with carbenes. No direct connection between charge and chemical shift was found.
Enhancing microteaching through additional feedback from preservice administrators

Abstract Two university professors integrate their courses to allow students to collaborate with each other in practicing new skills. The preservice administrators provide additional feedback to the preservice teachers on their microteaching while practicing their supervision skills. The data collected over 3 years from the preservice teachers enrolled in their first teaching methods course demonstrate that the preservice teachers were assisted with their transition into teaching. From the feedback they learned about their teaching skills, they found experienced teachers and the process of supervision as valuable to their professional growth, and shifted their perceptions of teaching.
Persisting complaints attributed to chronic lyme disease: Possible mechanisms and implications for management

A better understanding of the natural history of Lyme disease and of possible causes for persisting symptoms other than active infection is needed to optimize management of patients with persistent symptoms. Review of patients seen at a Lyme disease referral center and of the immunologic and clinical literature on Lyme disease suggests most symptoms that persist after therapy can be explained by one or more of seven proposed pathogenetic mechanisms, only one of which includes active ongoing infection. Individualization of care and reanalysis of patients problems are crucial if misdiagnosis and overtreatment of Lyme disease are to be avoided.
Distribution of putative amino acid transmitters, choline acetyltransferase and glutamate decarboxylase in the inferior colliculus.

Abstract Levels of glutamic acid, aspartic acid, glycine, taurine, alanine, choline acetyltransferase, and glutamate decarboxylase were measured in ten regions of the inferior colliculus in the cat. None of these substances were uniformity distributed in the colliculus. The highest concentrations of asparate occurred in central regions, whereas those of glycine were in ventral central regions. The distributions of glutamic acid and glutamate decarboxylase were highly correlated, with both being generally high in dorsal regions. There was also a high correlation in the distributions of taurine and alanine, with these substances having their highest concentrations in the posterior region and lowest concentrations in the anterior region. The concentration of choline acetyltransferase was highest in the anterior region. No consistent changes in any of the substances were seen following elimination of inputs ascending to the colliculus via the dorsal and intermediate acoustic striae. Small decreases in glutamic acid were seen in two extracentral regions following removal of the auditory cortex. The nonuniform distribution of the substances that were analyzed suggest that there may be previously undescribed differences in the structure and function of the inferior colliculus. The lack of change in the content of choline acetyltransferase and glutamate decarboxylase after lesion of inputs from the cortex or cochlear nucleus makes it unlikely that acetylcholine or α-aminobutyrate are transmitters in these pathways.
Physiological changes governing the onset of sexual receptivity in male mosquitoes

Abstract The effectors which erect antennal hairs in male mosquitoes are shown to be unresponsive to the neurotransmitter that triggers antennal hair erection until 12–24 hr after emergence. The unresponsive period can be prolonged by transfusion of haemolymph from newly-emerged males, or by injection of 20-hydroxyecdysone. This suggests that the hormone persisting after the metamorphosis from pupa to adult, affects the duration of the post-emergence delay in antennal hair erection and is indirectly responsible for timing the onset of sexual receptivity in male mosquitoes.
Calculating Prices and Sensitivities for Path-Independent Derivative Securities in Multifactor Models

Pricing derivatives written on assets whose prices depend on multiple factors can be difficult, even if payoffs depend only on prices at maturity. In complicated problems, Monte Carlo simulation is a popular technique, but it can be time-consuming when accuracy is needed. Conditional Monte Carlo is a known variance reduction method, but its use has been limited by a presumption in the literature that it can be used only when factors are instantaneously uncorrelated. I show that this presumption is not necessarily true. For example, we can express the prices and sensitivities of an European call option written on an asset that has stochastic volatility as an expectation over its Black-Scholes counterparts, even when the volatility and price processes exhibit instantaneous correlation. Combining this conditional Monte Carlo technique with low-discrepancy ("quasi-random") techniques provides price and delta estimators that require a fraction of a second to compute and yet have exact errors that are accurate to a few one-hundredths of a percent of the option's price. By comparison, conventional Monte Carlo simulation requires at least several minutes of computation time to achieve the same accuracy.
Depth judgments in a see-through head-mounted display

The goals of this research are to measure accuracy and precision of depth perception of 3D objects in se-through head-mounted displays for near-field visualization and to set benchmarks for current technology. In this paper we present results on accuracy and precision of perceived depth for stimuli of various forms presented either in a side by side or in a top-bottom configuration. A finding of these experiment is the unexpected relatively high human subject variability measured which we postulate to be correlated with aspects of the methodology used. Further investigations on methodology related to these types of experiments are being conducted. Finally, we report a new benchmark for the precision of perceived depth of 7 mm.
Towards a universal microprocessor

Abstract Currently available microprocessors appear to be a collection of unstructured integrated circuits. This paper examines the possibility of providing a uniform architecture for complex devices, such as microprocessors, through modular design. By example, four simple computational elements are shown to easily implement common digital devices. As a possible step toward a universal microprocessor a single computational element is defined which incorporates the features of the other four elements. Depending upon the storage and transformation units selected for implementation, this element could be equal in computational capability to any current microprocessor yet is structurally simpler and easily combined with similar elements.
THE DEVELOPMENT OF APOSPOROUS GAMETOPHYTES AND REGENERATED SPOROPHYTES FROM EPIDERMAL CELLS OF EXCISED FERN LEAVES: AN ANATOMICAL STUDY'

A B S T R A C T Three different types of outgrowths develop from epidermal cells of excised juvenile leaves of Microgramma vacciniifolia: aposporous gametophytes, intermediates, and regenerated sporophytic plantlets. The gametophytes and intermediates arise from derivatives of epidermal cell divisions which are developed to the exterior of the leaf surface, whereas the sporophytic regenerants originate from derivatives produced by cell divisions to the interior of the leaf. Anatomical observations of excised- leaves grown in vitro demonstrate that only the epidermal cells are stimulated to divide and give rise to the various types of outgrowths. Incorporation of tritiated thymidine by the nuclei of leaf epidermal cells gives further evidence for the metabolic activity of these cells. APOSPORY, the formation of diploid gametophytes
Smoking behavior among urban and rural Native American adolescents in California

Abstract Background Previous studies have documented a high prevalence of tobacco use among Native American adolescents. However, little is known about the smoking behavior of Native American adolescents who live in urban areas. This study used statewide data from California to examine the smoking behavior and related psychosocial risk factors among Native American adolescents living in urban and rural counties. Methods The Independent Evaluation of the California Tobacco Control Program conducted three population-based statewide surveys of 10th-grade California public school students in 1996, 1998, and 2000. Past-month smoking and psychosocial correlates were examined among 22,440 respondents, including 1060 Native Americans. Results Native Americans had a 32% excess risk of past-month smoking compared with other ethnic groups. Smoking prevalence did not differ between urban (27.7%) and rural (29.3%) Native Americans. Native Americans reported higher access to cigarettes and exposure to smoking peers than other groups. Those psychosocial variables explained some, but not all, of the excess risk of smoking among Native Americans. Conclusions Effective smoking prevention and cessation interventions are needed for Native American adolescents in urban and rural areas of California.
Albumin synthesis during induced and spontaneous metamorphosis in the bullfrog Rana catesbeiana

Abstract Treatment of premetamorphic tadpoles with triiodothyronine (T3) alters the in vivo distribution of radioactive amino acids among serum protein fractions. The effects on the albumin fraction have been interpreted as reflections of the relative rate of synthesis. About 12 hr after intraperitoneal injection of 2.5 × 10−10 mole of T3 per gram, there is an increase in the relative rate of albumin synthesis. The effect peaks on day 3 at 5 × the untreated level and returns to near the untreated level by day 6. Continuous immersion in 1 × 10−7 M T3 results in a similar stimulation of albumin synthesis, but with no decline after day 3. The timing of the response is independent of dose or route of T3 administration. The effect of T3 on the relative rate of albumin synthesis is also observed in froglets. There is a 6-fold increase in the relative rate of albumin synthesis during spontaneous metamorphosis peaking at stage XXI and returning to the premetamorphic level by stage XXV. The following was concluded: (1) The increase in the relative rate of albumin synthesis during metamorphosis results from increased endogenous thyroid levels. (2) Following a peak, the decline in albumin synthesis observed in induced and spontaneously metamorphosing animals is a result of decreasing thyroid hormone levels. (3) The effect of T3 on albumin synthesis may be the summation of two effects, a direct effect of T3 and a stimulation by amino acids from the resorbing tail. (4) A decreased relative rate of albumin degradation or a sparing of albumin is probably responsible for the elevated relative concentration of albumin in the serum of postmetamorphic animals.