cssi/SciSciGPT-SciSciNet huggingface dataset:
Abstract 15523: Absence of Chordae Tendineae near Valve Coaptation Leads to Mitral Regurgitation in Lone Atrial Fibrillation

Introduction: Mitral annuloplasty is performed to treat mitral valve regurgitation (MR) in lone atrial fibrillation (AF) patients. The mechanisms of the significant MR in lone AF patients are not known well. We assessed the hypothesis that absence of chordae tendineae near the mitral valve (MV) coaptation could lead to the significant functional MR in the lone AF patients. Methods: We analyzed 64 patients with a history of AF with greater than 50 % of the left ventricular (LV) ejection fraction, and no organic abnormality of MV. Of these 31 has mild or lesser MR (AF Groups) and 33 has moderate or severe MR (AFMR Group). We also analyzed 33 sinus rhythm patients with normal echocardiographic findings (Sinus Group). Parameters concerning to MV morphology were measured with commercial software. Chordae attaching points (CAPs) nearest from the coaptation line were detected on the anterior mitral leaflet (Figure). Ratio of the length from CAP to coaptation line against that from anterior annulus to coaptation ...
Quaternary benzylammonium ion rearrangements with organolithium compounds—I

Benzyltrimethylammonium (I) iodide reacts with n-butyllithium to produce α,N,N-trimethylbenzylamine (II) and o,N,N-trimethylbenzylamine (III) in a monomeric rearrangement process. A 51% total yield of the two simple tertiary amines contained II and III in the ratio of 1:3·8. Separation of the reaction products by gas chromatography and identification by IR and PMR indicated the absence of other rearrangement products [i.e. N-benzyl-N-ethylmethylamine (IV) and β-phenethyldimethylamine (V)] from the methyl ylide of I. The failure of V to be consumed in the presence of n-butyllithium eliminated secondary reactions as the feature limiting the number of observed products. The products II and III have previously been reported separately in other rearrangements of I.
Glutamate decarboxylase-immunoreactive neurons are preserved in human epileptic hippocampus

The present study was designed to determine whether inhibitory neurons in human epileptic hippocampus are reduced in number, which could reduce inhibition on principal cells and thereby be a basis for seizure susceptibility. We studied the distribution of GABA neurons and puncta by using glutamate decarboxylase (GAD) immunocytochemistry (ICC) together with Nissl stains. Using quantitative comparisons of GAD-immunoreactive (GAD-IR) neurons and puncta in human epileptic hippocampus and in the normal monkey hippocampus, we found that GAD-IR neurons and puncta are relatively unaffected by the hippocampal sclerosis typical of hippocampal epilepsy where 50-90% of principal (non-GAD-IR) cells are lost. GAD-IR neurons and puncta were not significantly decreased compared with normal monkey. In 6 patients, prior in vivo electrophysiology demonstrated that the anterior hippocampus generated all seizures. The anterior and posterior hippocampus were processed simultaneously, and the counts of hippocampal GAD-IR neurons were numerically greater in anterior than in the posterior hippocampus, where no seizures were initiated. These results indicate that GABA neurons are intact in sclerotic and epileptogenic hippocampus. Computerized image analysis of puncta densities in fascia dentata, Ammon's horn, and subicular complex in epileptic hippocampi (n = 7) were not different from puncta densities in the same regions in normal monkey (n = 2). Hence, despite the significant loss of principal cells (50-90% loss) GABA terminals (GAD-IR puncta) were normal, which suggests GABA hyperinnervation of the remnant pyramidal cells and/or dendrites in human epileptic hippocampus. The apparent increase in puncta ranged from 2 (fascia dentata) to 3.3 (CA1) times normal puncta densities. These findings would suggest increased inhibition and less excitability; however, those regions were epileptogenic. We suggest that GABA terminal sprouting or hyperinnervation of the few remnant projection cells may serve to synchronize their membrane potentials so that subsequent excitatory inputs will trigger a larger population of neurons for seizure onset in the hippocampus and propagation out to undamaged regions of subiculum and neocortex.
Fighting Cancer with Fitness: Dietary outcomes of a randomized, controlled lifestyle change intervention in healthy African-American women

Abstract Objectives. This study tested the efficacy of an 8-week, culturally targeted community-based nutrition and physical activity promotion intervention, Fight Cancer with Fitness! (FCF). Methods. A randomized, controlled trial was conducted in a black-owned commercial gym in a sample of 366 predominantly overweight or obese, healthy African–American women. Results. Dietary quality as indexed by fruit and vegetable intake improved significantly in the intervention group compared to the control group at 12-month follow-up, and proportion of calories consumed as fat decreased in both groups. Conclusions. This individually targeted cancer prevention intervention produced beneficial effects on dietary quality that were sustained for at least 12 months.
Studies on the digestion, absorption and metabolism of castor oil.

Abstract Ricinoleic acid is absorbed from the alimentary tract of the rat and can be detected in the chyle. During long term feeding of castor oil, ricinoleic acid is deposited in adipose tissue. After withdrawal of the oil it rapidly disappears from adipose tissue in a manner which suggests metabolic degradation of the fatty acid rather than excretion. In vitro experiments show that castor oil is hydrolyzed as well as and perhaps better than olive oil. On the other hand the activation of ricinoleic acid by rat intestine mucosal thiokinase may be less efficient than the activation of oleic acid. The early stages of the mechanism of castor oil purgation may depend on the rapid release, poor assimilation and therefore increasing concentration of free rieinoleie acid in the intestine. The nature of the “irritant action” of this fatty acid has still to be determined.
A method to define public transit opportunity space

A public transit performance measure quantifying the ease of reaching a destination from a given location is important for describing the efficiency and convenience of public transit. In this paper, a new method for quantifying public transit performance, the Transit Opportunity Index (TOI), is presented. This measure accounts for both transit accessibility (the level of access to the transit system) and transit connectivity (the system’s provision of services between origins and destinations) by combining measures of spatial coverage, temporal coverage, and trip coverage. Spatial and temporal coverage measures are calculated using an origin–destination (O–D) representation of the transit network and then combined to create a transit accessibility score for each O–D pair. Transit accessibility is weighted by a binary connectivity parameter and a connectivity decay factor. The connectivity decay factor is derived from a travel time-based logistic function to reflect the decreasing connectivity with increasing travel time. The binary connectivity parameter and the connectivity decay factor are used to account for trip coverage, or transit connectivity. The Transit Opportunity Index (TOI) is then applied to the bus network of the city of New Haven, Connecticut. The results of this case study suggest that the TOI is a more complete and practical measure of public transit service performance than previously established measures. This method also has the potential to identify transfer zones for public transit trips between O–D pairs without direct connections. However, the TOI is most powerful when used in conjunction with a public transit demand measure to identify underserved areas.
Easily assembled digital data acquisition system for the analytical ultracentrifuge.

Abstract A system for the acquisition of digital data from the analytical ultracentrifuge which uses a commercially available data acquisition board, a standard IBM compatible personal computer (PC), and an interface circuit has been developed. The system uses the signal from the standard Beckman scanner. Preliminary analysis and data reduction are performed at the PC within minutes of data acquisition using simple commercially available software, and final data fitting is performed with a mainframe computer. Procedures are described which allow approach to equilibrium to be followed and attainment of equilibrium to be demonstrated. Data density of ∼200 points per millimeter column height (∼500 points per 100 μ1 of sample) allows the use of short columns and hence short run times. Only 2 min are required to collect a complete scan, which is recorded in a format suitable for direct analysis by standard spreadsheet software. This allows multiple sequential scans to be quickly recorded at equilibrium and averaged to reduce noise prior to analysis. The combination of characteristics allows molecular weight determinations to be performed relatively quickly with only a few micrograms of protein. The system is inexpensive and easy to assemble given the centrifuge and a PC.
A meta-analysis of randomized trials of prenatal smoking cessation interventions+

Objective: Our purpose was to assess the effect of prenatal smoking interventions on rates of smoking cessation and low birth weight. Study Design: We used a meta-analysis model to compare and summarize smoking cessation and low birth weight outcomes with the risk ratio used as a common metric. We located 11 randomized, controlled trials with objective validation of smoking status; four of these studies also measured rates of low birth weight. Results: Risk ratios for smoking cessation ranged from 0.9 to 7.1. The combined risk ratio for the homogeneous group of 10 studies was 1.50 (95% confidence interval 1.22 to 1.86) after the outlier study with a risk ratio of 7.1 was excluded. This was a 50% increase in smoking cessation. Low birth weight risk ratios of 0.6 for two studies that achieved a 50% increase in cessation suggested that the incidence of low birth weight was decreased. Conclusion: Prenatal smoking cessation interventions increase rates of smoking cessation during pregnancy, and there is evidence that they reduce the incidence of low birth weight.
Experimental results from the Los Alamos FEL photoinjector

The authors report some initial measurements of electron beam properties from the new photoinjector installed as the front end on the Los Alamos free-electron laser (FEL). The FEL is being rebuilt with the photoinjector, added acceleration to 40 MeV, new diagnostics, and a beam line designed to minimize emittance growth. The authors measured the spatial and temporal properties of the beam at energies of about 15 MeV as a function of several parameters and the results have been compared to simulations. The operational characteristics of the important elements of the system and the theoretical comparisons are described. >
Tidally modulated occurrence of megaripples in a saturated surf zone

[1] An abstracted model for saturated surf zone megaripple occurrence, based on the hypothesis that megaripples form and persist unless flow conditions change too rapidly or the bed passes through the swash zone, correctly predicts the bed state (presence or absence of megaripples) for 73% of measurements over 1 year at Scripps Beach, more than seven standard deviations above the agreement between a random model and the measurements. Transitions between bed states are predicted within 1.5 hours for 54% of measurements, compared with 6% agreement for a random model. The model is forced with a record of water depth over the beach, H (from offshore tide measurements and inferred changes in bed elevation), assuming that changes in flow conditions and depth are determined by tide level alone in a saturated surf zone. Model parameter values are estimated independent of model results: megaripple formation time, T = 2.5 hours; maximum RMS depth change over time T, ΔHRMS* = 0.1 m; and minimum depth (averaged over time T) below which megaripples are smoothed, Hsw = 0.3 m. Allowing model parameters to vary increases agreement between measurements and model predictions to a maximum 82% for parameter values T = 3 hours, ΔHRMS* = 0.05 m, and Hsw = 0.1 m. Neither bed state nor bed state transitions are correlated with offshore wave conditions.
Surgical anatomy of the carpal tunnel

The author describes and details the anatomy of the carpal tunnel and surrounding structures pertinent to the surgical treatment of carpal tunnel syndrome. Potential complications of both open and endoscopic carpal tunnel release are discussed as well as techniques to avoid or minimize poor patient outcomes.
Some results on Liapunov functions and generated dynamical systems

Abstract This paper presents several results pertaining to the use of lower semicontinuous Liapunov functions in the analysis of autonomous abstract evolution equations. Such functions can be useful in setting up a nonlinear dynamical system that need not satisfy any exponential estimate, as well as in locating positive invariant sets of the resulting dynamical system. Other results concern the computation of the derivative of a lower semicontinuous Liapunov function, the use of such a function to assure precompactness of positive orbits, and a version of the Invariance Principle that is valid for lower semicontinuous Liapunov functions.
Effect of screening out implausible energy intake reports on relationships between diet and BMI

HUANG, TERRY T.-K., SUSAN B. ROBERTS, NANCY C. HOWARTH, AND MEGAN A. MCCRORY. Effect of screening out implausible energy intake reports on relationships between diet and BMI. Obes Res. 2005;13: 1205–1217. Objective: We present an updated method for identifying physiologically implausible dietary reports by comparing reported energy intake (rEI) with predicted energy requirements (pER), and we examine the impact of excluding these reports. Research Methods and Procedures: Adult data from the Continuing Survey of Food Intakes by Individuals 1994 to 1996 were used. pER was calculated from the dietary reference intake equations. Within-subject variations and errors in rEI [coefficient of variation (CV) 23%] over 2 days (d), pER (CV 11%), and measured total energy expenditure (mTEE; doubly labeled water, CV 8.2%) were propagated, where 1S D CV 2 rEI /d CV 2 pER CV 2 mTEE 22%. Thus, a report was identified as implausible if rEI was not within 78% to 122% of pER. Multiple cut-offs between 1 and 2 SD were tested. Results: %rEI/pER 81% in the total sample (n 6499) and progressively increased to 95% in the 1 SD sample (n 2685). The 1 to 1.4 SD samples yielded rEI-weight associations closest to the theoretical relationship (mTEE to weight). Weak or spurious diet–BMI associations were present in the total sample; 1 to 1.4 SD samples showed the strongest set of associations and provided the maximum n while maintaining biological plausibility. Discussion: Our methodology can be applied to different data sets to evaluate the impact of implausible rEIs on health outcomes. Implausible rEIs reduce the overall validity of a sample, and not excluding them may lead to inappropriate conclusions about potential dietary causes of health outcomes such as obesity.
Kinetics of Mercury(II) Adsorption and Desorption on Soil

Adsorption and desorption kinetics of Hg(II) on four soils at pH 6 were investigated to discern the mechanisms controlling the retention and release reaction rates of Hg(II) on soil. A stirred-flow method was employed to perform experiments. Apparent adsorption and desorption rate coefficients were determined by a one-site second-order kinetic model. Both adsorption and desorption were characterized by a biphasic pattern, a fast step followed by a slow step. After 2 min, the Hg(II) adsorbed for an 8 mg L-1 influent accounted for 4−38% of the total Hg(II) adsorbed within 5 h. Of the Hg(II) released within 8 h, 62−81% was desorbed during the first 100 min. Both adsorption and desorption rate coefficients were inversely correlated with the soil organic C content. Not all adsorbed Hg(II) was readily released. The greater the soil organic C content, the higher the fraction of Hg(II) that was resistant to desorption. The diffusion of Hg(II) through intraparticle micropores of soil organic matter may be the prin...
Discrimination between cholesterol and ergosterol by yeast membranes

Abstract The typical sterol of animal membranes (cholesterol) failed to support normal growth of yeast under anaerobic conditions when compared to the growth induced by the organism's natural sterol (ergosterol). This pathology was evident in strongly reduced numbers of cells, failure of budded cells to separate, and premature death. This study demonstrates that one or all of the Δ 5,7 -, Δ 22 -, and 24β-methyl groupings present in ergosterol are functionally significant.
Assessing the climate of an early childhood centre by using key features of organisational culture

SUMMARY The purpose of this study was to assess the teaching/learning environment of one early childhood education centre by combining a quantitative methodology that focused on the staff's perceptions of the learning environments with a qualitative methodology that focused on specific features of organisational culture. The rationale for conducting this assessment stemmed from indications that many members of the centre's staff were concerned that the centre had strayed from its original mission — a mission that focused on parent involvement in the education and care of young children. Results indicate that the centre's professional staff perceived significant differences between their actual and preferred teaching/learning environments. These differences were attributable to concerns staff members had regarding organisational dimensions such as unclear communication, lack of adherence to the school's stated mission and vision, changing expectations, and dissonance they perceived as originating at the le...
Purification and Characterization of an Estrogen-regulated Xenopus Liver Polysomal Nuclease Involved in the Selective Destabilization of Albumin mRNA

A previous report from this laboratory described an estrogen-regulated endoribonuclease activity on Xenopus liver polysomes which had properties one might expect for a messenger ribonuclease involved in the regulated destabilization of albumin mRNA (Pastori, R. L., Moskaitis, J. E., and Schoenberg, D. R.(1991) Biochemistry 30, 10490-10498). This report describes the purification and properties of this ribonuclease. The purified nuclease fraction contained a doublet of 62 and 64 kDa and a small amount of a 40-kDa peptide. In situ analysis on both denaturing and nondenaturing gels using an albumin transcript as substrate showed all three proteins possess nuclease activity. Peptide mapping and Western blot with a polyclonal antiserum showed the 62- and 64-kDa peptides to be isoforms, and the 40-kDa peptide to be a degradation product of the larger species. Two-dimensional gel electrophoresis further separated the 62- and 64-kDa species into three pairs of proteins, with isoelectric points of 9.6, 9.8, and 9.8. The purified ribonuclease rapidly degraded a full-length albumin transcript, yet had no effect on either a full-length albumin antisense transcript or full-length ferritin transcript. A number of properties of the purified nuclease were characterized, including the effects of salt, divalent cations, EDTA, sulfhydryl reagents, and temperature. Treatment of the polysomal nuclease with micrococcal nuclease had no effect, indicating that this enzyme does not require an RNA cofactor for activity. Finally, primer extension mapped the major cleavage site to an overlapping repeated sequence APyrUGA, with cleavage between and adjacent to the two pyrimidine residues generating fragments with 5′-hydroxyls.
Aspects of fight interference in free‐ranging and compound‐dwelling rhesus macaques (Macaca mulatta)

Patterns of fight interference (agonistic aiding) were compared among three groups of rhesus monkeys (Macaca mulatta) living in two settings: (1) two groups at Cayo Santiago (Caribbean Primate Center); and (2) one group at the Yerkes Regional Primate Research Center (YRPRC). A total of 1,227 interference episodes were recorded in 1,650 hours of observation. The only significant intergroup difference was the increased tendency of males at YRPRC to aid aggressors rather than victims. Among other findings, females aided relatives, interfered against target animals dominant to themselves, aided juveniles, and aided victims more consistently and frequently than did males. Importantly, female interference became more male-like in pattern when aid was given to nonrelatives. Neither the dominant males nor males in general displayed a unique or consistent tendency to interfere in fights in a manner which could be interpreted as controlling aggression. The males' interference patterns also did not suggest they were forming coalitions to either attain or defend status rankings. It is concluded that, overall, observations of compound-dwelling and free-ranging rhesus monkeys reveal similar relationships. Further, while female rhesus monkeys interfered in fights in a manner consistent with the control of aggression and protection of kin, the motives of male interferers remain unknown; however, their behavior is consistent with the hypothesis that they were reducing intermale tensions while, at the same time, minimizing physical risk.
A multi-valent vaccine approach that elicits broad immunity within an influenza subtype

Vaccines directed toward individual strains of highly variable viruses like influenza lose efficacy when the circulating viruses no longer resemble the vaccine isolate. Historically, inclusion of more than one isolate per subtype of influenza has been limited by the need to include large doses of antigen with typical protein-based vaccine approaches and by concerns that an immunodominant response to one antigen will limit the response to closely related antigens. Here we provide proof of principle demonstrating that a multi-valent vaccine directed against multiple influenza A virus hemagglutinins (HAs) can elicit broad, neutralizing immunity against multiple strains within a single influenza subtype (H3). We employed a DNA vaccine to direct immunity toward the HA component alone, and a live attenuated influenza virus (LAIV) to assess immunity against the whole virus. Delivery of either HA-DNA or LAIV yielded broad protective immunity across multiple antigenic clusters, including heterologous strains, that was similar to the combined immunity of each antigen assessed separately. Priming with HA-DNA followed by an LAIV boost strengthened and broadened the antibody response toward all three H3 HAs. This prime:boost multi-valent approach was thus able to elicit immunity against multiple strains within the H3 subtype without evidence of immune interference between closely related antigens. Although the trivalent vaccine described here is not a universal vaccine, since protection was limited to circulating viruses from about a two-decade period, these data suggest that full protection within a subtype is possible using this approach with multiple antigens from current and predicted future influenza strains.
Review article: the modern diagnosis and therapy of cholangiocarcinoma

Cholangiocarcinomas are epithelial neoplasms that originate from cholangiocytes and can occur at any level of the biliary tree. They are broadly classified into intrahepatic tumours, (extrahepatic) hilar tumours and (extrahepatic) distal bile duct tumours. In spite of well-understood predispositions, most cholangiocarcinomas arise in the absence of risk factors. In suspected cases, the diagnosis can be established with non-invasive imaging studies. Biliary invasion should be reserved for patients with obstruction. In high-risk patients, advanced cytological tests of aneuploidy (digital image analysis and fluorescent in situ hybridization) aid early diagnosis. In the absence of primary sclerosing cholangitis, curative surgical resection has 5-year survival rates of 2-43%, higher survival observed in patients with clear surgical margins and concomitant hepatic resection for hilar tumours. Patients with unresectable cholangiocarcinoma or pre-existing primary sclerosing cholangitis should be considered for liver transplantation with neoadjuvant chemoirradiation, in specialized centres.
In Situ Observation of Heterogeneous Growth of CdSe Quantum Dots: Effect of Indium Doping on the Growth Kinetics

In this study, the heterogeneous growth of CdSe nanoparticles is reported by using in situ fluorescence spectroscopy. In the heterogeneous growth regime, nanoparticles with well-defined and very di...
Modification of a correlation‐based circulation pattern classification to reduce within‐type variability of temperature and precipitation

When a correlation-based circulation pattern classification was applied to daily 700 hPa heights for 25 summer seasons, and the circulation types were related to surface temperature and precipitation for the Lake Superior basin, within-type variability was found to be high. Regarding temperature, the difference between warm and cold days of a type is a positive height anomaly centred to the east of the lake, which is very similar to the height anomaly for winter temperatures identified in an earlier study. The difference between wet and dry days of a type is a pattern quite unlike that for temperature. It is a dipole pattern consisting of a negative anomaly to the northwest of the lake and a positive anomaly to the east and southeast. These small-scale circulation components were missed by the correlation-based classification because they are much smaller than the differences in height between circulation types. Regression models, relating monthly mean temperature anomalies to circulation type frequencies, produced results comparable to those obtained for winter temperature. For precipitation, the variance explained by the regression models is only half that obtained for temperature. Two approaches were used to reduce within-type variability and to improve the regression results: the division of the first few circulation types into warm/cold and wet/dry subtypes on the basis of differences in 700 hPa vorticity (an approach introduced in the earlier paper), and a modified correlation-based circulation pattern classification. The modification consisted of raising the correlation threshold for a few selected grid-points to capture the small-scale circulation component and also, of lowering the threshold for the comparison between maps and map sectors in order to minimize the number of unclassified days. Of the two approaches used to reduce within-type variability, the modified classification scheme produced superior results. In particular, the variance in precipitation explained by the regression models is about 30% higher than that achieved using vorticity to create subtypes. Copyright © 2000 Royal Meteorological Society
Stability of Walrasian and Marshallian adjustment mechanisms in multiple markets

Comparing the convergence of a Walrasian price adjustment process and that of a Marshallian quantity adjustment process in a multiple market setting, we show that both mechanisms are locally stable for any adjustment speeds if the demand system is characterised by a negative dominant diagonal.
Microwave and millimetre wave sensors for crack detection

Non-destructive detection and evaluation of stress-induced fatigue cracks in metals is an important practical issue in several critical environments including surface transportation (steel bridges, railroad tracks, railroad car wheels, etc.), aerospace transportation (aircraft fuselage, landing gears, etc.) and power plants (steam generator tubings, etc.). Although there are several standard non-destructive evaluation techniques, near-field microwave and millimetre wave techniques have shown tremendous potential for significantly adding to the available non-destructive 'toolbox' for this purpose. This paper serves as a review of recent advances made in this area and the capabilities of these techniques for detecting cracks and evaluating their various dimensional properties including determining a crack tip location accurately. These techniques include using open-ended rectangular probes (in two distinct modes) and open-ended coaxial probes.
A resource-minimalist flow size histogram estimator

The histogram of network flow sizes is an important yet difficult metric to estimate in network monitoring. It is important because it characterizes traffic compositions and is a crucial component of anomaly detection methods. It is difficult to estimate because of its high memory and computational requirements. Existing algorithms compute fine grained estimates for each flow size, i.e. 1, 2,... up to the maximum number observed over a finite time interval. Our approach instead relies on the insight that, while many applications require fine grained estimates of small flow sizes, i.e. {1,2,...,k} with a small k, network operators are often only interested in coarse grained estimates of larger flow sizes. Thus, we propose an estimator that outputs a binned histogram of size distributions. Our estimator computes this histogram in O(k3 + log W) operations, where W is the largest flow size of interest to the network operator, while requiring only a few bits of memory per measured flow. This translates into more than 4 fold memory savings and an exponential speedup in the estimator as compared to previous works, greatly increasing the possibility of performing on-line estimation inside a router.
Glycolytic pH oscillations in a flow reactor

A new type of flow reactor (UCSTR) has been developed that uses anisotropic ultrafiltration membranes in a continuous flow stirred tank reactor (CSTR) to facilitate the study of nonlinear enzyme catalyzed reactions. The design allows the study of enzymes with subunit molecular weights > or = 9000 dalton and protein concentrations up to at least 2 mg/ml under flow conditions with a residence time of 3 min or more, in a reactor of volume 1.67 ml. The UCSTR allows continuous potentiometric or spectrophotometric measurement without design change. Calibration of reactor performance was carried out by reproducing pH oscillations in the ferrocyanide-hydrogen peroxide reaction. Experimental verification of oscillatory glycolysis in the UCSTR was carried out with extract of rat skeletal muscle. Input feeds were fructose-6-phosphate and ATP with low concentrations of phosphate as buffer. Oscillations in pH, sustained for over eight hours, were observed. A six-step mechanism, including product activation and substrate inhibition, seven concentration variables, and four enzymes sufficed simulate the pH oscillations observed in the UCSTR.
CITIES AS PEOPLE, CITIES AS PLACES: URBAN REVITALIZATION AND URBAN CONFLICT

Just as the decades of the 50s and 60s were the age of suburbia, the 70s brought, for many, a return to the city and to an increasingly urban way of life. Analysis of this phenomenon by social scientists has resulted in the production of a large number of displacement studies, virtually all of which demonstrate the same thing: young, middle-class, usually childless professionals move into an urban neighborhood and, while materially improving the neighborhood, typically displace the indigenous population. This paper argues that in the long run, this process of displacement, as important as it is, is but one of a large number of consequences ensuing from urban revitalization. Many of these are far more subtle and far more potentially troublesome, and, to the degree to which they leave legacies of intraurban conflict and result in the loss of a sense of community, are likely to be far more difficult problems with which urban areas shall have to deal.
A Study of Penetrating Cosmic-Ray Showers in Water

Penetrating showers produced locally by non-ionizing radiation were studied using counter techniques. The collision length in water of the non-ionizing component which is capable of producing penetrating showers was found to be (98\ifmmode\pm\else\textpm\fi{}13) g/${\mathrm{cm}}^{2}$. Comparison of this collision length with that expected from the geometrical cross section seems to indicate that the hydrogen nuclei in water have a rather small cross section for the production of penetrating showers by neutral radiation. Results obtained at two elevations were used to calculate the absorption length in air of the neutral penetrating shower producing component. The absorption length measured, (115\ifmmode\pm\else\textpm\fi{}19) g/${\mathrm{cm}}^{2}$, agrees with that obtained by others for the total penetrating shower producing component.
Innovation Focus: the Patient with Arrhythmia

Great strides have been made over the last two decades in the management of patients with rhythm disorders. Despite this, however, the remaining critical problems of stroke related to atrial fibrillation or as a result of radiofrequency ablation require innovative solutions to fully realize the potential of these recent advances. Similarly, implanted cardiac devices have revolutionized the care of patients with bradyrhythmias and tachyarrhythmias. Dyssynchronus ventricular pacing associated with present devices; however, results in heart failure, tricuspid regurgitation, and inappropriate device therapy once again create a demand for creative solutions. While not technically an arrhythmia, epilepsy management today is riddled with many of the problems that plagued cardiac arrhythmia management previously, and thus an appreciation of the similarities in requirement for investigative solutions may yield groundbreaking solutions. In this paper, we describe some novel methods to reduce complications associated with rhythm disorders and their treatment and apply the lessons learned from cardiovascular arrhythmia management to the brain. These include: a method to reduce coagulum formation and thus subsequent thromboembolism with indwelling catheters specifically during radiofrequency ablation procedures; a technique to ligate the left atrial appendage through percutaneous subxiphoid pericardial access; development and testing of a novel intramyocardial pace-sense lead, particularly used in a unique anatomic location (the atrioventricular septum) to allow pacing the ventricles in a relatively synchronous manner without crossing the tricuspid valve or entering the coronary sinus; finally, novel modifications of the cardiovascular mapping and ablation techniques used for the management of the central nervous system disorders primarily via the venous drainage of the brain. Innovative and potential solutions to treat the patient with arrhythmia are presented.
The Evolution of the Lithium Abundances of Solar-Type Stars. VIII. M67 (NGC 2682)

We have used the HIRES spectrograph on the Keck 10 m telescope to obtain echelle spectra of 25 solar-type stars in the old open cluster M67 (NGC 2682) and have used these spectra to derive lithium abundances. This cluster, which has approximately the same age and composition as the Sun, shows a pattern of Li depletion different from either the Pleiades or the Hyades. At M 1 M⊙, M67 is more Li depleted than the Hyades. For ~1 M⊙ stars, M67 shows a significant spread in Li, with about two-thirds of the stars being Li-rich and the remainder Li-poor. The data are consistent with M67 having the same initial Li abundance as the initial solar abundance. This is further evidence that Li depletion in solar-type stars occurs during their main-sequence lifetimes, although at a slower rate than pre–main-sequence depletion. These M67 observations also indicate that a 1 M⊙ star at the Sun's age can have an Li abundance within a range of ~1 dex, and that the Sun is not necessarily representative of all stars of its mass, age, and composition.
The carpal tunnel: ultrasound display of normal imaging anatomy and pathology

Ultrasound successfully displays the normal anatomy and pathology of the median nerve in the carpal tunnel. This article reviews the sonographic characteristics of carpal tunnel anatomy, including the superficially situated median nerve, the contained tendons and vessels, and the boundary-forming fibro-osseous landmarks. It emphasizes ultrasound evaluation of the median nerve and the criteria for diagnosis of compressive neuropathy in carpal tunnel syndrome. The techniques for performing sonography for carpal tunnel syndrome are detailed. Ultrasonic imaging is more comfortable for patients, less time-consuming, and less expensive than MR imaging, and achieves equal accuracy in skilled hands.
SUPPLY CONTROL WITH LIMITED INFORMATION: AN ECONOMETRIC STUDY OF TOBACCO PRODUCTION IN GREECE

In the absence of explicit data that would facilitate a direct measure of the variable degree of control over exportable tobacco in Greece, a statistical measure was devised for it corresponding to the probability that control did adversely affect production in a particular year. This was measured by simulating the supply equations from the free market period over the control period and relating the discrepancies to the standard errors of the simulated values. The period 1948–1980 was re-analysed using this control variable jointly with lagged prices as supplementary ‘independent’ variables. The best estimate of the long-run price elasticity is considered to be near 3 but falls below 2 with a normal degree of control. The normal long-run effect of control on production was near 30%. Other effects of considerable importance were the level of the rural population, weather and trend. The analysis required the use of several sophisticated econometric techniques including Schmidt's formula for the error of a cumulative projection.
A Global Parallel Model Based Design of Experiments Method to Minimize Model Output Uncertainty

Model-based experiment design specifies the data to be collected that will most effectively characterize the biological system under study. Existing model-based design of experiment algorithms have primarily relied on Fisher Information Matrix-based methods to choose the best experiment in a sequential manner. However, these are largely local methods that require an initial estimate of the parameter values, which are often highly uncertain, particularly when data is limited. In this paper, we provide an approach to specify an informative sequence of multiple design points (parallel design) that will constrain the dynamical uncertainty of the biological system responses to within experimentally detectable limits as specified by the estimated experimental noise. The method is based upon computationally efficient sparse grids and requires only a bounded uncertain parameter space; it does not rely upon initial parameter estimates. The design sequence emerges through the use of scenario trees with experimental design points chosen to minimize the uncertainty in the predicted dynamics of the measurable responses of the system. The algorithm was illustrated herein using a T cell activation model for three problems that ranged in dimension from 2D to 19D. The results demonstrate that it is possible to extract useful information from a mathematical model where traditional model-based design of experiments approaches most certainly fail. The experiments designed via this method fully constrain the model output dynamics to within experimentally resolvable limits. The method is effective for highly uncertain biological systems characterized by deterministic mathematical models with limited data sets. Also, it is highly modular and can be modified to include a variety of methodologies such as input design and model discrimination.
An initial exploration of the relevance of complexity theory to group research and practice

The purpose of this paper is to describe some findings from an ongoing investigation of naturally occurring groups and to discuss them utilizing concepts from complexity theory. The paper proposes that groups meet the criteria outlined by complexity theorists for designation as complex adaptive systems. Research evidence from an ongoing investigation of group dynamics and development is provided to support this conclusion. The paper concludes that integrating concepts from complexity theory and group development theory provides a different way of thinking about groups, group research, and group consultation and intervention.
Integer Programming with Bounded Variables via Canonical Separation

This paper presents a new algorithm for integer programming with bounded variables which is efficient when m < n and when the upper bounds on the variables are small. The main idea is the application of the Balas and Jeroslow canonical hyperplanes and the systematic search of integer points over certain faces of the feasible region. During each iteration the integer points on a certain face are examined, and then this whole face is discarded from the feasible region of a linear programming problem. After a bounded number of iterations, the optimal integer solution is found, if one exists.
In vivo assessment of calcium alginate gel for endovascular embolization of a cerebral arteriovenous malformation model using the Swine rete mirabile.

Objective We sought to assess the stability of calcium alginate as an embolic agent in an animal model of a cerebral arteriovenous malformation (AVM). Swine cerebral AVM models were used to test the injectability, radiographic visualization, mechanical stability, and biocompatibility of calcium alginate as an occlusive agent. Methods The swine cerebral AVM model included a carotid-to-jugular anastomosis to increase flow to the rete mirabile (RM), thereby simulating the pressure gradient and shunted blood flow of an AVM. Alginate and the reactive component, calcium chloride, were injected from double-lumen microcatheters to form a complete RM occlusion in the "acute swine" AVM model and a partial occlusion in a "survival swine" model. Results Angiographic and histological results verified complete occlusion of the left RM in acute animals when alginate was injected in stages. Partial RM occlusion in the survival animals blocked blood flow to the inferior portion of the RM but left flow open to the superior portion of the RM and the circle of Willis. One-week survival results showed that the alginate remained a stable occlusive material. Histological results showed a minor bioactive response and encapsulation of the alginate polymer, thereby increasing the stability and effective occlusion of the embolization material. Conclusion Calcium alginate proved to be an effective endovascular occlusion material that blocked blood flow to the swine RM. The swine AVM models provided assessment of alginate injectability and effective occlusion and provided initial in vivo characteristics of alginate stability and biocompatibility.
Flux and brightness calculations for various synchrotron radiation sources

Abstract Simple expressions for flux, central intensity, vertical opening angle, effective source size (horizontal and vertical), and brightness of bending magnets and ordinary planar insertion devices (undulators and wigglers) on synchrotron radiation (SR) storage rings are compiled. These expressions are evaluated for existing SR sources at the National Synchrotron Light Source (NSLS) and planned SR sources at the Advanced Light Source (ALS) and the Advanced Photon Source (APS). All necessary storage ring and insertion device parameters are listed in tables. The flux, central intensity, and brightness of all of the calculated SR sources are plotted for comparison.
A Study of Epstein-Barr Virus BRLF1 Activity in a Drosophila Model System

Epstein-Barr virus, a member of the herpesvirus family, infects a large majority of the human population and is associated with several diseases, including cancer. We have created Drosophila model systems to study the interactions between host cellular proteins and the Epstein-Barr virus (EBV) immediate-early genes BRLF1 and BZLF1. BRLF1 and BZLF1 function as transcription factors for viral transcription and are also potent modifiers of host cell activity. Here we have used our model systems to identify host cell genes whose proteins modulate BRLF1 and BZLF1 functions. Via our GMR-R model system, we have found that BRLF1 expression results in overproliferation of fly tissue, unlike BZLF1, and does so through the interaction with known tumor suppressor genes. Through an additional genetic screen, we have identified several Drosophila genes, with human homologs, that may offer further insights into the pathways that BRLF1 interacts with in order to promote EBV replication.
Near-optimal autonomous pursuit evasion for nonholonomic wheeled mobile robot subject to wheel slip

A new approach to autonomous pursuit evasion by a wheeled mobile robot in the presence of wheel slip is presented. Classical pursuit evasion problem, such as the Homicidal Chauffeur problem, considers the kinematic model of the pursuer and does not consider slip in its trajectory, and thus cannot predict a realistic pursuit evasion scenario. In this work we present a new dynamics-based approach to pursuit evasion problem in the presence of wheel slip. We first show how a feedback linearization controller can achieve capture with wheel slip. We then improve the capture time by designing a new extremum seeking controller that maximizes lateral traction force to effect a sharper but stable turn. The simulation results show the efficacy of our proposed control approach.
Multiobjective analysis of market transformation strategies

The objective of the U.S. Department of Energy’s Volume Purchase Program is to work with utilities to market emerging energy and water efficient technologies. Using a volume purchase strategy, the Department of Energy wants to transform the U.S. market for new, energy and water efficient clothes washers to increase and hasten market acceptance of these appliances. This paper describes how multiobjective decision analysis is used to evaluate market transformation strategies for high-efficiency clothes washers. The three alternatives being considered are (1) volume purchases; (2) utility rebates; and (3) no incentives. A Hill’s goals-achievement matrix methodology is used to analyze the ability of each alternative to meet the goals of environmental and energy conservation and economic improvement. The differing viewpoints of the consumer, utility, appliance manufacturer, and U.S. government are considered in the evaluation. The results of the analysis show that the volume purchase option is marginally superior to the utility rebate option. The option to offer no incentives is a significantly inferior alternative to the other proposed alternatives.
Abnormal 24-hydroxylation of 25-hydroxyvitamin D in the X-linked hypophosphatemic mouse.

The effect of extracellular phosphate on the control of 25-hydroxyvitamin D3 24-hydroxylase was studied in normal mice and littermates with X-linked hypophosphatemic rickets (Hyp). 24-Hydroxylase activity and plasma concentrations of 24,25-dihydroxyvitamin D3 were significantly higher in Hyp mice than in normal mice when both groups were fed a normal diet containing 1.22% calcium (Ca) and 0.8% phosphorus (Pi). The differential in 24-hydroxylase activity was exaggerated when serum phosphate was reduced in normal mice by means of a low Pi diet or increased in Hyp mice by means of a high Pi diet. Differences in 24-hydroxylase activity between the two groups of mice were also demonstrated in the presence of varying Pi concentrations in vitro. Thus, in both Hyp and normal mice, 24-hydroxylase activity is influenced in a qualitatively similar manner by serum Pi. Plasma concentrations of 1,25-dihydroxyvitamin D3 were the same in normal and Hyp mice. The data are consistent with the hypothesis that control of the...
Suppression of nuclear polarization near the surface of optically pumped GaAs

We measured the spin dependence of polarized neutrons reflected by a GaAs sample as it was optically pumped. This dependence was correlated with the helicity of the circularly polarized light and found to oscillate with neutron wave vector transfer. The data provide definitive evidence that optically induced nuclear polarization in GaAs is not uniform with depth. Quantitative analysis of the data shows that nuclear polarization is suppressed for tens of nanometers near the surface of GaAs.