cssi/SciSciGPT-SciSciNet huggingface dataset:
Natural frequencies of cross-ply laminated panels with matrix cracks

exit circumference. The number of vortex pairs corresponds with the number of perturbations. 2) The combination of discrete perturbations along the exit circumferenceand swirling results in a  ow structure that consists of a central swirling jet surrounded by vortices with the opposite sense of rotation. The number of outer vortices again corresponds with the number of perturbations. 3) For swirling jets with four or more perturbations, the effect is con ned to a few diameters downstream from the exit. 4) The swirling jet with three perturbations develops a stable, three-lobed structure that persists farther than 10 diameters downstream from the exit. 5) The swirling jet with two perturbationsdevelops a stable, twolobed structure that persists farther than 10 diameters from the exit.
Theoretical development and experimental validation of a thermally dissipative cohesive zone model for dynamic fracture of amorphous polymers

Abstract A thermally dissipative cohesive zone model is developed for predicting the temperature increase at the tip of a crack propagating dynamically in a nominally brittle material exhibiting a cohesive-type failure such as crazing. The model assumes that fracture energy supplied to the crack tip region that is in excess of that needed for the creation of new free surfaces during crack advance is converted to heat within the cohesive zone. Bulk dissipation mechanisms, such as plasticity, are not accounted for. Several cohesive traction laws are examined, and the model is then used to make predictions of crack tip heating at various crack propagation speeds in the nominally brittle amorphous polymer PMMA, observed to fail by a crazing-type mechanism. The heating predictions are compared to experimental data where the temperature field surrounding a high speed crack in PMMA was measured. Measurements are made in real time using a multi-point high speed HgCdTe infrared radiation detector array. At the same time as temperature, simultaneous measurement of fracture energy is made by a strain gauge technique, and crack tip speed is monitored through a resistance ladder method. Material strength can be estimated through uniaxial tension tests, thus minimizing the need for parameter fitting in the stress-opening traction law. Excellent agreement between experiments and theory is found for two of the cohesive traction law temperature predictions, but only for the case where a single craze is active during the dynamic fracture of PMMA, i.e. crack tip speed up to approximately 0.2cR. For higher speed fracture where subsurface damage becomes prominent, the line dissipation model of a cohesive zone is inadequate, and a distributed damage model is needed.
Characterization of prediagnostic symptoms among primary epithelial ovarian cancer cases and controls.

Abstract Objective The goal of this study was to characterize types, frequency, combinations, and relative onset of symptoms among ovarian cancer cases and controls. Methods Participants were from an ongoing, population-based, case–control study of primary epithelial ovarian cancer in a 48-country region of North Carolina. Incident cases ( N = 267), aged 20–74, were identified by area hospitals on a rapid case ascertainment basis between April 1999 and March 2001. Population-based controls, with at least one intact ovary, frequency matched on age and race, were identified using random-digit dialing ( N = 287) and Health Care Financing Administration (HCFA) phone lists ( N = 30). Trained nurse-interviewers, using a standardized questionnaire, asked participants about specific symptoms experienced for at least 2 weeks in the year prior to diagnosis (cases)/interview (controls). Results More than 90% of cases reported at least one symptom and symptoms were most often the reason for the doctor visit leading to diagnosis (74%), followed by routine examination (12%). Among invasive cases, symptoms with onsets longer before diagnosis (median 5–7 months) included gas/nausea/indigestion; urinary frequency/urgency; bowel irregularity; abnormal menstrual/vaginal bleeding or discharge; pain during intercourse; and ongoing fatigue. Symptoms with onsets closer to diagnosis (median of 2–4 months) included distended/hard abdomen; bloating/feeling of fullness; unexplained weight gain/loss; pelvic/abdominal discomfort; chest pain/respiratory difficulties; and "other" symptoms. Controls reported fewer symptoms than cases (median 1 vs 5 or 6). Control symptoms were of longer duration and much less likely to occur in combination. Conclusion Earlier diagnosis of ovarian cancer may be possible if women and physicians recognize the importance of combinations of seemingly unrelated symptoms, especially those identified as occurring longer before diagnosis.
Empathy: A Social Cognitive Neuroscience Approach

There has been recent widespread interest in the neural underpinnings of the experience of empathy. In this review, we take a social cognitive neuroscience approach to understanding the existing literature on the neuroscience of empathy. A growing body of work suggests that we come to understand and share in the experiences of others by commonly recruiting the same neural structures both during our own experience and while observing others undergoing the same experience. This literature supports a simulation theory of empathy, which proposes that we understand the thoughts and feelings of others by using our own mind as a model. In contrast, theory of mind research suggests that medial prefrontal regions are critical for understanding the minds of others. In this review, we offer ideas about how to integrate these two perspectives, point out unresolved issues in the literature, and suggest avenues for future research.
Comparison of some common ratio estimators using pitman measure of nearness

In this article we compare some common ratio estimators for estimating the population total of a given characteristic. The sampling schemes considered are simple random sampling (S.R.S.) and S.R.S.under stratification. The comparisons are made using the Pitman Nearness criterion under the model-based approach. The error term is assumed normal with mean zero and variance σg(x). The function g(x) is a known function of the auxiliary variable x. Special interest is on the cases of g(x) =l and x. The result is found the same as that using MSE criterion, although the PN is very different from the MSE intrinsically.
Chlorpromazine metabolism. V. Disposition of free and conjugated metabolites in blood fractions of schizophrenic patients.

Disposition of the circulating levels of 10 chlorpromazine metabolites and their conjugates in the blood fractions of chronic schizophrenic patients was determined. The erythrocytes were found to sequester nearly 50% of the total blood concentration of the free metabolites, whereas the platelets contained only insignificant amounts. Of particular significance was the localization of the conjugated metabolites in the red cells. The implications of sequestration of the metabolites and their conjugates by the erythrocytes are discussed.
Bayesian estimation and prediction of the intensity of the power law process

In analyzing failure data pertaining to a repairable system, perhaps the most widely used parametric model is a nonhomogeneous Poisson process with Weibull intensity, more commonly referred to as the Power Law Process (PLP) model. Investigations relating to inference of parameters of the PLP under a frequentist framework abound in the literature. The focus of this article is to supplement those findings from a Bayesian perspective, which has thus far been explored to a limited extent in this context. Main emphasis is on the inference of the intensity function of the PLP. Both estimation and future prediction are considered under traditional as well as more complex censoring schemes. Modern computational tools such as Markov Chain Monte Carlo are exploited efficiently to facilitate the numerical evaluation process. Results from the Bayesian inference are contrasted with the corresponding findings from a frequentist analysis, both from a qualitative and a quantitative viewpoint. The developed methodology is...
Factors associated with colorectal cancer screening in a population-based study: the impact of gender, health care source, and time.

Abstract Introduction. The effectiveness of colorectal cancer screening in reducing incident colorectal cancer and the risk of death has been shown. Despite campaigns to promote the benefits of and use of colorectal cancer screening, most people are not participating in screening. In this paper, we examine factors associated with screening behavior over time, by health care provider, and by gender and report associations between screening and development of colorectal cancer after adjusting for diet and lifestyle factors. Methods. Data from two population-based case-control studies of colorectal cancer were used to examine risk associations with nonparticipation in colorectal cancer screening. Study participants were identified for the first study between 1991 and 1994 (N = 1,346 cases and 1,544 controls) and for the second between 1997 and 2001 (N = 952 cases and 1,205 controls) and were asked to complete a detailed in-person interviewer-administered diet and lifestyle questionnaire. The control population is used to examine changes in screening behavior and associations with screening over time. Results. Significantly, fewer people reported fecal occult blood test (FOBT) in 1997–2001 than in 1991–1994 (62.5% in 1991–1994 vs. 47.2% in 1997–2001); a slight nonsignificant increase in sigmoidoscopy screening was reported for these periods among controls (33.9% vs. 36.6%). In the control population, during these periods, there was a statistically significant increase in the number of people who reported having had a sigmoidoscopy for screening rather than for problems (72.6% in 1997–2001 vs. 63.8% in 1991–1994). There were differences in factors associated with screening behavior by time, by sex, and by health care provider, although having a family history of colorectal cancer, having more education, and being male was associated with more screening in all settings. After adjusting for diet and lifestyle factors, we observed that non-sigmoidoscopy screening significantly influenced risk of incident cancer (rectal OR: 2.9; 95% CI, 2.3–3.7; distal tumor OR: 1.8; 95% CI, 1.4–2.3); proximal tumor: 1.4; 95% CI, 1.1–1.8). Nonuse of FOBT also was associated significantly with tumors in the rectal (OR: 1.6; 95% CI, 1.3–1.9) and distal (OR: 1.4; 95% CI, 1.1–1.8) sites. Summary. These data reinforce the importance of screening to reduce risk of colorectal cancer development. However, flexible sigmoidoscopy screening is increasing only modestly over time, and primarily in settings where a significant investment in screening has been made. FOBT screening, which is effective for rectal cancer prevention, is actually decreasing.
A possible link between Balkan endemic nephropathy and the leaching of toxic organic compounds from Pliocene lignite by groundwater: preliminary investigation

Abstract Balkan endemic nephropathy (BEN) is a fatal kidney disease that is known to occur only in clusters of villages in alluvial valleys of tributaries of the Danube River in Bulgaria, Romania, Yugoslavia, Bosnia, and Croatia. The confinement of this disease to a specific geographic area has led to speculation that an environmental factor may be involved in the etiology of BEN. Numerous environmental factors have been suggested as causative agents for producing BEN, including toxic metals in drinking water, metal deficiency in soils of BEN areas, and environmental mycotoxins to name a few. These hypotheses have either been disproved or have failed to conclusively demonstrate a connection to the etiology of BEN, or the clustering of BEN villages. In previous work, we observed a distinct geographic relationship between the distribution of Pliocene lignites in the Balkans and BEN villages. We hypothesized that the long-term consumption of well water containing toxic organic compounds derived from the leaching of nearby Pliocene lignites by groundwater was a primary factor in the etiology of BEN. In our current work, chemical analysis using 13 C nuclear magnetic resonance ( 13 C NMR ) spectroscopy indicated a high degree of organic functionality in Pliocene lignite from the Balkans, and suggested that groundwater can readily leach organic matter from these coal beds. Semi-quantitative gas chromatography/mass spectroscopy analysis of solvent extracts of groundwater from shallow wells in BEN villages indicated the presence of potentially toxic aromatic compounds, such as napthalene, fluorene, phenanthrene, and pyrene at concentrations in the ppb range. Laboratory leaching of Balkan Pliocene lignites with distilled water yielded soluble organic matter (>500 MW) containing large amounts of aromatic structures similar to the simple/discrete aromatic compounds detected in well water from BEN villages. These preliminary results are permissive of our hypothesis and suggest that further work on the possible relationship between the etiology of BEN and toxic aromatic substances leached from Pliocene lignites in well water is warranted.
A wideband integrated circuit amplifier for fixed-gain application

Circuits which achieve precise gains without the use of negative feedback are of interest because of their simplicity and potential for achieving large bandwidths. A circuit architecture based upon precision current mirrors for producing fixed gains without the use of feedback has been reported in the literature and implemented on a BiCMOS process [1]. This paper provides further analysis of this approach and applies it to a new bipolar amplifier, intended for such applications as real-time active filter synthesis.
B 74-26 Discrete Mathematical Structures and Their Applications

Computer Science bears approximately the same relationship to computers as Aerodynamics bears to sailboats. It describes how they work but has little impact on their design which is based almost entirely on intuition strengthened and controlled by experience. However, one day, the Wright brothers of the "ultra-computer" will get to their Kitty Hawk and Computer Science will come into its own. In preparation for that day stands the present volume. It is an excellent mathematics textbook written by an experienced teacher.
Cu/Ni interface study for bump reliability improvement

Under Bump Metallization (UBM) quality is crucial to the reliability of flip chip products. This paper focuses on the failure mechanism that attributed to Temperature Humidity Bias (THB) test. The importance of metal film condition is emphasized, and the effect of voltage bias is discussed. In addition, a detailed experiment on Cu/Ni UBM interface is carried out for THB improvement. The investigation scope contains Cu surface topography and Cu/Ni interface adhesion. Based on the experiment results, the optimal process condition has been determined. A notable improvement of THB performance is achieved after process optimization.
Development from Within? The Potential for Geographical Indications in the Global South

In debates in the World Trade Organization over the protection of geographical indications (GIs), the European Union (EU) has framed its position in terms of the potential for GIs to protect local cultures, offer a quality guarantee to consumers, and provide opportunities for value-added agriculture. A key tenet of the EU's argument is that GI schemes can be successfully implemented in developing countries as well as Europe. However, my analysis of the case of tequila shows that GIs in developing countries face unique challenges. Tequila is the oldest GI outside of Europe, and is often cited as an example of a successful GI in a developing country. Despite obvious successes in terms of its market share, however, the GI for tequila has largely failed to benefit the local population and environment. My examination of the tequila case illustrates how, throughout the history of the evolving GI legislation for tequila, influential actors have manipulated production standards in ways that contradict the theoretical concept of a GI and negatively affect the overall quality of tequila. I situate this case within the larger framework of international legislation on GIs, arguing that higher standards and a more context-specific approach are necessary.
Self-assembly of recombinant prion protein of 106 residues.

The central event in the pathogenesis of prion diseases is a profound conformational change of the prion protein (PrP) from an α-helical (PrPC) to a β-sheet-rich isoform (PrPSc). The elucidation of the mechanism of conformational transition has been complicated by the challenge of collecting high-resolution biophysical data on the relatively insoluble aggregation-prone PrPSc isoform. In an attempt to facilitate the structural analysis of PrPSc, a redacted chimeric mouse-hamster PrP of 106 amino acids (MHM2 PrP106) with two deletions (Δ23−88 and Δ141−176) was expressed and purified from Escherichia coli. PrP106 retains the ability to support PrPSc formation in transgenic mice, implying that it contains all regions of PrP that are necessary for the conformational transition into the pathogenic isoform [Supattapone, S., et al. (1999) Cell 96, 869−878]. Unstructured at low concentrations, recombinant unglycosylated PrP106 (rPrP106) undergoes a concentration-dependent conformational transition to a β-sheet-ric...
Relationship Between Plaque Mineralization In Vitro and Calculus Formation In Vivo

Twenty-four hour plaque samples from humans were tested for mineralizing activity. Dental calculus samples also were taken from the same individuals and data for each individual were correlated. Results showed a positive correlation between the mineralizing activity of a 24-hour plaque sample and the amount of dental calculus formed in the same individual's mouth.
Evaluation of Dicationic Reagents for Their Use in Detection of Anions Using Positive Ion Mode ESI-MS Via Gas Phase Ion Association

Twenty-three different dications were investigated for their effectiveness in pairing with singly charged anions, thereby allowing the electrospray ionization mass spectrometry (ESI-MS) detection of anions as positively charged complexes. Nitrate, iodide, cyanate, monochloroacetate, benzenesulfonate, and perfluoro-octanoate were chosen as representative test anions as they differ in mass, size-to-charge ratio, chaotropic nature, and overall complexity. Detection limits were found using direct injection of the anion into a carrier liquid containing the dication. Detection limits are given for all six anions with each of the 23 dications. Each anion was easily detected at the ppb (µg/L) and often the ppt (ng/L) levels using certain dicationic reagents. The ability of dicationic reagents to pair with anions and produce ESI-MS signals varied tremendously. Indeed, only a few dications can be considered broadly useful and able to produce sensitive results. Liquid chromatography (LC)-ESI-MS also was investigated and used to show how varying the dicationic reagent produced significantly different peak intensities. Also, the use of tandem mass spectrometry can lead to even greater sensitivity when using imidazolium based dications.
Analysis of Overall Perchlorate Removal Rates in Packed-Bed Bioreactors

Perchlorate (ClO-4) can be used as a terminal electron acceptor by some bacteria for cell respiration during the oxidation of substrates. Packed-bed biofilm reactors have been used to treat perchlorate-contaminated waters with rates varying over six orders of magnitude (0.0007 to 20 mg/L-min). While this range implies large differences in treatment efficiencies, it is demonstrated in this report that these rates are correlated to concentrations of perchlorate in the reactor. Overall perchlorate reduction rates obeyed first-order kinetics for reactors using organic substrates as electron donors (acetate or a complex high-protein medium). Higher reaction rates appear possible in hydrogen-gas feed reactors rather than in organic-feed reactors, although additional work is necessary to confirm this preliminary result. Findings of first-order perchlorate kinetics will help engineers design packed-bed reactors for the remediation of perchlorate-contaminated waters.
Characterization of a cellular protein that promotes SV40 infection in human cells.

Publisher Summary This chapter discusses the characterization of a cellular protein that promotes SV40 infection in human cells. Studies show that a cellular protein promotes SV40 infection of cultured primate cells. The protein is released into the medium by uninfected cells that are susceptible (permissive) to productive SV40 infection. This protein, designated as enhancer, facilitates the infection of human cells that exhibit low susceptibility to SV40. Addition of the SV40 enhancer before or with virus to cultured semipermissive host cells results in approximately 100-fold increases in the number of infected cells as determined by the plaquing efficiency of infectious centers and/or by immunofluorescence of nuclear SV40 T-antigen utilizing specific, fluorescein-conjugated antisera. A direct relationship exists between the susceptibility of SV40 infection and presence of active enhancer in uninfected cell cultures. Simian cells (CV-1) are very susceptible to SV40 and release easily detectable amounts of SV40 enhancer activity (10 unit/ml). In contrast, semipermissive human fibroblasts release minimal amounts of enhancer activity, and nonpermissive WISH and chick embryo fibroblast cells do not release any detectable SV40 enhancer activity. Thus, the amount of SV40 enhancer activity recovered from cell cultures coincided with the ability of SV40 to infect these cells.
Factors of Information Credibility for an Internet Advice Site

Information credibility is important to Internet advice site vendors because they primarily build a revenue stream based on how credible consumers consider the information on the website. Unless consumers believe the websites information is credible, they are not likely to be willing to act on the advice. This paper reports on an empirical study of how individual differences and initial site impressions affect perceptions of website information credibility. Results confirm that most of the proposed individual difference and initial impression variables play an important role in how consumers view the credibility of an unfamiliar website. Implications are included regarding adapting websites to take into account initial site impressions and individual differences.
An adaptive hybrid data fusion based identification of skeletal muscle force with ANFIS and smoothing spline curve fitting

Precise and effective prosthetic control is important for its applicability. Two desired objectives of the prosthetic control are finger position and force control. Variation in skeletal muscle force results in corresponding change of surface electromyographic (sEMG) signals. sEMG signals generated by skeletal muscles are temporal and spatially distributed that result in cross talk between adjacent sEMG signal sensors. To address this issue, an array of nine sEMG sensors is used with a force sensing resistor to capture muscle dynamics in terms of sEMG and skeletal muscle force. sEMG and skeletal muscle force are filtered with a nonlinear Teager-Kaiser Energy (TKE) operator based nonlinear spatial filter and Chebyshev type-II filter respectively. Multiple Takagi-Sugeno-Kang Adaptive Neuro Fuzzy Inference Systems (ANFIS) are obtained using sEMG as input and skeletal muscle force as output. Outputs of these ANFIS systems are fitted with smoothing spline curve fitting. To achieve better estimate of the skeletal muscle force, an adaptive probabilistic Kullback Information Criterion (KIC) for model selection based data fusion algorithm is applied to the smoothing spline curve fitting outputs. Final fusion based output of this approach results in improved skeletal muscle force estimates.
History and dating of the publication of the Philadelphia (1822) and London (1823) editions of Edwin James's Account of an expedition from Pittsburgh to the Rocky Mountains

The public record of Major Stephen H. Long's 1819–1820 exploration of the American north-west, Account of an expedition from Pittsburgh to the Rocky Mountains, compiled by Edwin James, contains valuable contributions regarding the natural landscapes, native peoples and wildlife of a mostly unexplored region of the American west compiled from the notes of some of America's foremost naturalists, and it includes the first descriptions of 67 new species. The original plan was to publish the Account in Philadelphia and London simultaneously, yet these two editions differ substantially in ways that are relevant to the taxonomic contributions in the work. It is generally assumed that the Philadelphia edition was published in early January 1823 and was available first, but little substantive evidence has been presented to support its priority over the London edition. Review of contemporary correspondence and periodicals indicates the Philadelphia edition was available and for sale on 31 December 1822, whereas the...
Dense Matrix Inversion of Linear Complexity for Integral-Equation-Based Large-Scale 3-D Capacitance Extraction

State-of-the-art integral-equation-based solvers rely on techniques that can perform a dense matrix-vector multiplication in linear complexity. We introduce the H2 matrix as a mathematical framework to enable a highly efficient computation of dense matrices. Under this mathematical framework, as yet, no linear complexity has been established for matrix inversion. In this work, we developed a matrix inverse of linear complexity to directly solve the dense system of linear equations for the 3-D capacitance extraction involving arbitrary geometry and nonuniform materials. We theoretically proved the existence of the H2 matrix representation of the inverse of the dense system matrix, and revealed the relationship between the block cluster tree of the original matrix and that of its inverse. We analyzed the complexity and the accuracy of the proposed inverse, and proved its linear complexity, as well as controlled accuracy. The proposed inverse-based direct solver has demonstrated clear advantages over state-of-the-art capacitance solvers such as FastCap and HiCap: with fast CPU time and modest memory consumption, and without sacrificing accuracy. It successfully inverts a dense matrix that involves more than one million unknowns associated with a large-scale on-chip 3-D interconnect embedded in inhomogeneous materials with fast CPU time and less than 5-GB memory.
ABSORPTION OF VOLATILE METHYL KETONES BY A NATURAL MODEL SYSTEM: FREEZE‐DRIED CREAM

A technique was pursued for the enrichment of a dried model system by exposure of the system to an atmosphere of volatile flavor compounds. As the exposure time was lengthened, the quantity of each of the flavor compounds absorbed by the freeze-dried cream increased. Short chain methyl ketones were absorbed by the dehydrated cream in larger amounts than those determined for the higher molecular weight homologs. In these experiments the desorption, during frozen storage, of highly volatile ketones from freeze-dried cream exposed to 2-alkanones was greater than that obtained for the high molecular weight homologs. To compensate for the loss of highly volatile flavor constituents during prolonged storage, a dried food product could be enriched above the normal level. Following storage, residual levels of such volatiles would more closely approximate the initial concentration in the food. The application of these findings to a commercial absorption process could be of value in improving the flavor and odor characteristics of a dehydrated food, or in the fabrication of completely new synthetic foods or food analogs.
The Starfish Twins: Two Young Planetary Nebulae with Extreme Multipolar Morphology

We present alpha images of two objects, He 2-47 and M1-37, obtained during a Hubble Space Telescope imaging survey of young planetary nebulae (PNs) selected on the basis of their low-excitation characteristics.
Tazobactam is a potent inactivator of selected inhibitor-resistant class A β-lactamases

The β-lactam β-lactamase inhibitor combinations (ampicillin/clavulanate, ampicillin/sulbactam, ticarcillin/clavulanate and piperacillin/tazobactam) were tested against selected inhibitor-resistant class A β-lactamases of the TEM and OHIO-1 varieties. Minimum inhibitor concentrations (MIC) revealed that the Escherichia coli DH5α transconjugate strains that possessed the OHIO-1 β-lactamase, Met69Ile mutant of the OHIO-1 β-lactamase, TEM-30 (Arg244Ser) and TEM-31 (Arg244Cys) β-lactamase were most susceptible to piperacillin and piperacillin/tazobactam. Kinetic experiments with each β-lactamase demonstrated that tazobactam was 10-25-fold more potent than clavulanate or sulbactam against TEM-30 and TEM-31 β-lactamase. Tazobactam was also as effective as clavulanate against the Met69Ile mutant of the OHIO-1 β-lactamase. Among the clinically available β-lactams and β-lactamase inhibitors, piperacillin/tazobactam appears to be the most potent combination against selected inhibitor-resistant strains of TEM and OHIO-1 β-lactamase.
Pathophysiology of Oxygen Delivery in Respiratory Failure

Complex physiologic interactions exist between oxygenation, hemoglobin, and cardiac output (Qt) in critically ill patients with respiratory failure. When any or all of these three critical factors fail, clinicians are challenged to support oxygen delivery (DO(2)) in order to avoid tissue hypoxia, end-organ damage, and high mortality rates. Many of the interventions performed to improve DO(2), including mechanical ventilation, blood transfusions, fluid management, and invasive monitoring of cardiac function, are accompanied by serious risks that can exacerbate the pathology of DO(2). This article provides an overview of oxygenation, hemoglobin, and Qt in patients with respiratory failure and highlights some of the current research that seeks safe and effective ways to improve DO(2) in these patients.
Ubiquinone at Center N Is Responsible for Triphasic Reduction of Cytochrome b in the Cytochromebc 1 Complex

We have examined the pre-steady state reduction kinetics of the Saccharomyces cerevisiae cytochromebc 1 complex by menaquinol in the presence and absence of endogenous ubiquinone to elucidate the mechanism of triphasic cytochrome b reduction. With cytochromebc 1 complex from wild type yeast, cytochromeb reduction was triphasic, consisting of a rapid partial reduction phase, an apparent partial reoxidation phase, and a slow rereduction phase. Absorbance spectra taken by rapid scanning spectroscopy at 1-ms intervals before, during, and after the apparent reoxidation phase showed that this was caused by a bona fide reoxidation of cytochrome b and not by any negative spectral contribution from cytochromec 1. With cytochrome bc 1complex from a yeast mutant that cannot synthesize ubiquinone, cytochrome b reduction by either menaquinol or ubiquinol was rapid and monophasic. Addition of ubiquinone restored triphasic cytochrome b reduction, and the duration of the reoxidation phase increased as the ubiquinone concentration increased. When reduction of the cytochrome bc 1 complex through center P was blocked, cytochrome b reduction through center N was biphasic and was slowed by the addition of exogenous ubiquinone. These results show that ubiquinone residing at center N in the oxidized cytochrome bc 1 complex is responsible for the triphasic reduction of cytochrome b.
Rapid alteration of stress-induced hypothalamic–pituitary–adrenal hormone secretion in the rat: A comparison of glucocorticoids and cannabinoids

The hypothalamic-pituitary-adrenal (HPA) axis self-regulates through a glucocorticoid negative feedback mechanism that is stereotypically slow and long lasting. Rapid (seconds to minutes) glucocorticoid feedback, however, inhibits stress-induced adrenocorticotropic hormone (ACTH) secretion too quickly to result from classic transcriptional effects of the occupied glucocorticoid receptor. Cannabinoids may act as rapid intermediary messengers between glucocorticoids and HPA activation via retroactive inhibition of afferent glutamate stimulation of the corticotropin-releasing factor neurons in the paraventricular nucleus. We demonstrated fast feedback effects of GR stimulation and blockade and observed the effect of cannabinoid receptor (CB1) antagonist AM251 on HPA axis reactivity in vivo. Rats were injected intraperitoneally with varying doses of the specific GR agonist RU28362, the GR antagonist RU486, or AM251 2 min before restraint. Blood was collected at predetermined times and corticosterone and ACTH concentrations were measured. RU28362 blunted stress-induced ACTH secretion while RU486 and AM251 significantly increased stress-induced ACTH release 15 min after restraint onset. Next, we injected AM251 58 min before RU28362, 2 min before restraint, to determine if inhibition of ACTH by RU28362 was contingent on CB1 activation. Unexpectedly, CB1 blockade failed to prevent glucocorticoid negative feedback and instead enhanced it. These studies not only establish an in vivo fast feedback model but show that rapid glucococorticoid negative feedback is similarly altered by GR and CB1 blockade. Although the hormonal consequences of acute AM251 treatment were strikingly similar to those of RU486 treatment, we are unable to draw conclusions about the serial nature of the interaction between GR activation and CB release from these results.
BIOCHEMICAL COMPOSITION AND PHOTOSYNTHETIC CARBON METABOLISM OF NUTRIENT LIMITED CULTURES OF MERISMOPEDIA TENUISSIMA (CYANOPHYCEAE)1

Continuous cultures of Merismopedia tenuissima Lemmerman, limited by phosphorus, nitrogen, sulfur, or carbon, were compared to non limited batch cultures by two methods. The cellular content of photosynthetic pigments (chlorophyll and phycocyanin) was found to decrease in all nutrient limited cultures, except for the carbon limited culture. The ratio of carbohydrate to protein was 4- to 7-fold higher in P, N or S limited cultures than in non-limited or C limited cultures. The macromolecular products of photosynthesis were determined in samples to which NaH14CO3 was added. Relative incorporation into protein decreased in P or N limited cultures, increased accumulation of low molecular weight compounds was found in S and P limited cultures, and little change was noted in C limited cultures as compared to non-limited cultures. Although relative incorporation into protein was significantly greater at 20μEin·m−2·s−1 light intensity than at 180 μEin·m−2.s−1 in non-limited cultures, this effect was abolished in all nutrient limited cultures. These results suggest that measurement of the cellular carbohydrate to protein ratio and the products of photosynthesis would be useful in the analysis of algal population dynamics in nature.
Novel Aerosol/Gas Inlet for Aircraft-Based Measurements

A novel inlet has been designed for selective sampling of gas and aerosol phases of volatile species from high-speed aircraft. A multistage flow system brings the flow nearly isokinetically towards the sampling port. Two small airfoil-shaped "blades" are placed close to the sample port to provide the flow conditions required for aerosol and gas sampling. Aerosols are sampled when these blades are positioned to operate the inlet as a counterflow virtual impactor (CVI). The design enables sampling of particles as small as 0.1 w m from a high-speed aircraft under stratospheric conditions, a substantial improvement over that possible with previous CVI designs. For gas sampling, one of the blades is moved by a stepper motor to occlude the inlet opening and gas is sampled perpendicular to the bulk flow. Boundary layer suction is used to prevent the sampled gas from coming in contact with the impactor walls. This is one of the first designs of an inlet that enables gas sampling free of wall contact. The inlet was flown on the NASA ER-2 aircraft during the SOLVE 2000 campaign to study aerosol/gas partitioning of nitric acid in the lower stratosphere. Data from the flight tests show that the inlet flow characteristics are broadly in agreement with computational fluid dynamics (CFD) simulations.
Human-Assisted Obstacle Avoidance System using 3D Workspace Modeling for Construction Equipment Operation

Equipment operation on construction sites is a major source of construction accidents and injuries related to crushing, electrocution, and falls. Primarily, this is because the operator’s field of view, reaction speed, attention, and depth perception are limited, and also because the construction site is a dynamic environment. Accelerating advances in sensing and equipment control sophistication present new opportunities to address these safety problems. The research described here provides the basis for the development of obstacle-avoidance systems that use models of objects generated by rapid three-dimensional (3D) workspace modeling methods and by sophisticated equipment control capabilities. An explanation of the proposed obstacle avoidance system, together with preliminary results, is presented. Implementation of this system in practice is feasible in the near term for critical and particularly hazardous operations.
TARIFF PROTECTION IN AN OPEN SPATIAL ECONOMY

Spatial pricing models have been used to illustrate a tariff's asymmetric effects on consumers located at different points in the protected economy, and to demonstrate that the optimum tariff for a small open spatial economy may be positive. In these models, the distribution of households has been taken as uniform and fixed. We extend the spatial model by allowing households to optimally locate and consume variable amounts of land, as well as the domestic- or foreign-produced good. Land consumption, location rents, and the distribution of consumers are endogenous, responding to tariff-induced changes in the delivered prices of the domestic and foreign goods. Within this limited general equilibrium framework, a neoclassical result resurfaces: from the perspective of private consumers, the optimum tariff in a small open economy is zero. The possibility of a positive optimum tariff, however, may remain intact in a more integrated model where domestic profits and tariff revenues are redistributed within the spatial economy.
Laser-Induced Fluorescence Measurements of Nitric Oxide Formation in High-Pressure Premixed Methane Flames

ABSTRACT We have obtained quantitative LIF measurements of NO concentration in the postflame zone of a series of flat, laminar, premixed CH4/O2/N2 flames (0.5 ≤ φ ≤ 1.6) at pressures ranging from l-14.6atm. The temperatures of the flames were 1660-J 960 K, indicating that prompt NO was the primary pathway for NO formation in the majority of these flames. In addition, we have modeled many of the experimental flames using the chemical reaction mechanism of Glarborg-Miller-Kee as modified by Drake and Blint (GMK-DB). This model accurately predicts the behavior of NO with increasing pressure and shows reasonable quantitative agreement for many of the flames at pressures ≤ 6.1 atm. At pressures greater than 6.1 atm, inaccuracies in the predicted temperature field preclude good quantitative agreement between the modeled and measured NO concentrations. Detailed NO measurements in ultra-lean (φ = 0.55−0.8) flames showed higher NO emissions with increasing pressure, a result consistent with kinetic modeling of the...
Evolving Judgments of Terror Risks: Foresight, Hindsight, and Emotion.

The authors examined the evolution of cognitive and emotional responses to terror risks for a nationally representative sample of Americans between late 2001 and late 2002. Respondents’ risk judgments changed in ways consistent with their reported personal experiences. However, they did not recognize these changes, producing hindsight bias in memories for their judgments. An intensive debiasing procedure failed to restore a foresightful perspective. A fear-inducing manipulation increased risk estimates, whereas an anger-inducing manipulation reduced them—both in predictions (as previously observed) and in memories and judgments of past risks. Thus, priming emotions shaped not only perceptions of an abstract future but also perceptions of a concrete past. These results suggest how psychological research can help to ensure an informed public.
Carbon fiber reinforced mortar as an electrical contact material for cathodic protection

Abstract For a joint between old plain mortar and new mortar (which serves as an electrical contact material for cathodic protection of steel-reinforced old mortar), short carbon fiber addition to the new mortar was found to decrease both the contact resistivity and the new mortar's volume resistivity. Whether the new mortar contained fibers or not, the contact resistance was higher than the new mortar's volume resistance perpendicular to the contact and was lower than the new mortar's volume resistance parallel to the contact. In the presence of latex, the volume resistivity was 3.1 × 105, 1.4 × 103 and 1.2 × 102 Ω.cm and the contact resistivity was 5.9 × 106, 2.7 × 105 and 2.6 × 104 Ω.cm2 at fiber contents of 0, 0.53 and 1.1 vol. % respectively. Latex addition alone to the new mortar increased slightly both contact resistivity and new mortar's volume resistivity. All resistivities increased very slightly with curing age.
Extended Leach Studies of Actinide-Doped SRL 131 Glass

The effects on the leachability of SRL 131 glass as a result of slight changes in the glass composition were monitored by leachate and surface analyses. The compositional changes had marked effects on solution and layer composition and on the precipitated alteration products that formed after 546 days of static leaching. The leaching behavior of long-lived actinide elements were measured, with Pu and Am showing little tendency to become solubilized and Np and U continuously accumulating in solution.
Giant fluctuations of second harmonic generation on nanostructured surfaces

Abstract On the basis of spectral-expansion Green’s function theory, we theoretically describe the fundamental harmonic (FH) and second harmonic (SH) local fields at nanorough surfaces of silver and gold. The numerical simulation of these fields in the model of random planar composites has shown that the SH local-field intensity possesses power-law (scaling) distribution for a wide range of system and excitation parameters, which is indicative of giant fluctuations of the SH local fields. Though these scaling phenomena are universal, the scaling index of the SH intensity distribution is not universal depending on the material, excitation frequency, and the fill factor of the nanosystem. The results obtained are in qualitative agreement with the existing experiments.
Spatial Decision Support System for Low-Income Families: Relocation Tool for the Chicago, Illinois, Region

Housing relocation or housing mobility is not uncommon in the United States, with the average family relocating once every 6 years. As part of this process, individuals and families take into account a variety of factors. One of the important factors is that of transportation and its availability. Various researchers have studied the impact of transportation information on relocation choice. However, the need for a structured methodology that incorporates various factors, such as transportation, has been highlighted from a study of the current practice of relocation counseling. The objectives of this paper are threefold: (a) to develop an analytical hierarchy process to rank census tracts for relocation purposes of individuals, (b) to present a prototype of the spatial decision support system (SDSS) with an example, and (c) to evaluate the impact of relocation choice of individuals by using a spatially unconstrained approach. With data from the six-county northeastern Illinois region, the SDSS is developed and showcased with the help of a sample application. Two scenarios are tested for each respondent. The first is based on only housing criteria, and the second compares all criteria in the analytical hierarchy process matrix with each other. The improvements in travel time determined from the results of the two scenarios are compared, and the results are discussed to highlight the salient features of the decision support system.
Optimal Design of One-Way and Two-Way Coherent Communication Links

This paper is concerned with the optimal design of one-way and two-way communication systems which are of greatest interest in space applications. A two-way communication system is defined to be one composed of two radio links or channels, viz., an up-link channel and a down-link channel. The down-link RF carrier is derived from the carrier tracking loop located in the uplink receiver. Transmission of information which does not make use of the carrier derived in the up-link receiver is referred to as oneway communications. In particular, a design technique is presented in the form of a universal set of design curves which enable the communications engineer to make a "best" choice of parameters when faced with a given set of design constraints. This means that, given a certain desired error probability, a total transmitter power limitation, data rate, and carrier tracking loop bandwidth, the modulation index, i.e., the square root of the ratio of the power in the carrier to the total transmitted power, may be chosen so as to minimize the probability of error. As an alternate technique, and one which is not as difficult to carry out, the design may be predicted on the basis of selecting that value of modulation index which maximizes the signal-to-noise ratio at the output of the data demodulator. Design curves are given which allow one to employ this alternate criterion. Further, these results should prove useful when attempting to check experimentally a design based upon the criterion of minimum error probability.
The Role of Private Events in the Interpretation of Complex Behavior

Like most other sciences, behavior analysis adopts an assumption of uniformity, namely that principles discovered under controlled conditions apply outside the laboratory as well. Since the boundary between public and private depends on the vantage point of the observer, observability is not an inherent property of behavior. From this perspective, private events are assumed to enter into the same orderly relations as public behavior, and the distinction between public and private events is merely a practical one. Private events play no role in the experimental analysis of behavior, but they permit us to make sense of many commonplace phenomena where controlled observation is impossible but unsystematic data are available. Such interpretive exercises serve both to guide research and to displace occult explanations.
Teaching about the traumatic impact of vehicular crashes: rock 'n' roll never forgets.

Editor’s Note: In this column, teachers who are currently using literary and artistic materials as part of their curricula will briefly summarize specific works, delineate their purposes and goals in using these media, describe their audience and teaching strategies, discuss their methods of evaluation, and speculate about the impact of these teaching tools on learners (and teachers). Submissions should be three to five double-spaced pages with a minimum of references. Send your submissions to me at University of California, Irvine, Department of Family Medicine, 101 City Drive South, Building 200, Room 512, Route 81, Orange, CA 92868-3298. 949-824-3748. Fax: 714-456-7984. jfshapir@uci.edu.
Real Exchange Rates, Non-Linearities and Balassa-Samuelson Effects

Using random simulations with artificial data with identical sample characteristics to the long-sample exchange rate data employed by Lothian and Taylor(Lothian, J.R. and Taylor, M.P.(1996). The recent float from the perspective of the past two centuries. Journal of Political Economy 104, 488-509.), we show that standard unit-root tests have extremely low power over sample sizes corresponding to the recent float. The probability of rejecting the null hypothesis when it is false is extremely low with 20 years or even 50 years of data and only reaches an acceptable level over much longer spans.