cssi/SciSciGPT-SciSciNet huggingface dataset:
Echocardiography in the Era of COVID-19: Lessons for the Future.

Purpose of review Poor cardiovascular outcomes are linked to COVID-19 in patients with or without prior cardiovascular disease or risk factors. Echocardiography, as a portable, versatile, and comprehensive imaging technique, has been on the frontlines. Yet sonographers and physician imagers are at increased risk of contracting or transmitting COVID-19. Recent findings Recent scientific statements incorporate triaging approaches to identify the appropriateness of imaging exam indications, coupled with triaging of indications. Additionally, focused protocols, procedures to reduce exposure, and point-of-care ultrasound play significant roles. Lessons learned during COVID-19 will apply to future pandemics. Echocardiography is a key diagnostic modality during pandemics in patients with or without prior cardiac diseases and risk factors. Attention to clinical questions, focused protocols, novel procedures, and future developments in imaging will contribute to safe and effective practice of echocardiography.
Finding Truth in Cause-Related Advertising: A Lexical Analysis of Brands’ Health, Environment, and Social Justice Communications on Twitter

Consumers increasingly desire to make purchasing decisions based on factors such as health, the environment, and social justice. In response, there has been a commensurate rise in cause-related marketing to appeal to socially-conscious consumers. However, a lack of regulation and standardization makes it difficult for consumers to assess marketing claims; this is further complicated by social media, which firms use to cultivate a personality for their brand through frequent conversational messages. Yet, little empirical research has been done to explore the relationship between cause-related marketing messages on social media and the true cause alignment of brands. In this paper, we explore this by pairing the marketing messages from the Twitter accounts of over 1,000 brands with third-party ratings of each brand with respect to health, the environment, and social justice. Specifically, we perform text regression to predict each brand’s true rating in each dimension based on the lexical content of its tweets, and find significant held-out correlation on each task, suggesting that a brand’s alignment with a social cause can be somewhat reliably signaled through its Twitter communications — though the signal is weak in many cases. To aid in the identification of brands that engage in misleading cause-related communication as well as terms that more likely indicate insincerity, we propose a procedure to rank both brands and terms by their volume of “conflicting” communications (i.e., “greenwashing”). We further explore how cause-related terms are used differently by brands that are strong vs. weak in actual alignment with the cause. The results provide insight into current practices in causerelated marketing in social media, and provide a framework for identifying and monitoring misleading communications. Together, they can be used to promote transparency in causerelated marketing in social media, better enabling brands to communicate authentic valuesbased policy decisions, and consumers to make socially responsible purchase decisions.
Big bluestem as a bioenergy crop: A review

Abstract Big bluestem (Andropogon gerardii) is an ecologically dominant warm-season (C4) perennial native grass that comprises as much as 80% of the plant biomass in prairies in the grasslands of the North American Midwest. Ranchers adopted the species as a forage crop long ago, but its high cellulosic content and low agricultural input requirements recently have made big bluestem a promising feedstock for ethanol production and bio-oil. The objective of this paper is to review big bluestem׳s potential as a bioenergy crop with respect to both biology and conversion. Biology includes distribution and adaptation of big bluestem, ecotypes and varieties currently studied, production management, and disease and pest control. Conversion includes discussion of the conversion of big bluestem biomass to bio-ethanol and bio-oil. Estimated ethanol yield of big bluestem is about 1886 L/ha, which is comparable to previously reported herbaceous biomasses. Various constraints and potential applications of big bluestem as an energy crop are analyzed in the final section of this paper. Plant breeding research that focuses on modifying big bluestem composition to minimize recalcitrance to bioconversion and increasing biomass yields is imperative.
Pictures and Words: Analogies and Specificity in Knowledge Organization

In this paper we want to examine what kind of relationship exists between two semiotic systems, word and picture, and the formats of conceptual representation linked to them: propositional thinking and mental imagery. The specific aim of this research is to explore the characteristics of the representation and organization of knowledge referring to the meaning of an input-word (“elephant”), which we have considered in both types of communication: verbalization and graphic representation. The current study analyzes the verbalizations and the graphic representations of 75 pre-school children when using the input-word “elephant”. Data seem to match the hypothesis of differentiation, according to which language plays the role of a filter, so that the choice of a language (verbal or iconic) activates preferential connections to the format of representation more similar to it.
High-Density Intro to Information Devices

The Physics of Information Technology . Neil Gershenfeld. Cambridge University Press, Cambridge, 2000. 384 pp. $39.95, £24.95. ISBN 0-521-58044-7. Gershenfeld offers a concise but wide-ranging account of the physical processes that underlie and constrain information technology.
Potent bile salt and organic anion inhibition of methotrexate uptake and accumulation in the freshly isolated rat hepatocyte.

Abstract Influx of [3H]methotrexate into freshly isolated hepatocytes is mediated by high- and low-affinity processes, both of which are inhibited by the bile salts, cholate, taurocholate, and deoxycholate, and the organic anions, bromosulfophthalein and rose bengal. At 100 µm concentrations, these compounds inhibit 1 µm [3H]methotrexate influx by 70 to 90%. Dixon plots established a similar Ki (∼20 µm) for taurocholate inhibition of the high- and low-affinity influx routes for methotrexate, although the kinetics of this inhibition has not, as yet, been established. Bile salt inhibition of methotrexate influx requires the simultaneous presence of the bile salt and methotrexate at the cell membrane. Hence, pretreatment of hepatocytes with taurocholate, with subsequent removal of the bile salt from the extracellular compartment, does not alter methotrexate influx. Methotrexate at high concentration was found to inhibit the influx of [3H]taurocholate, suggesting the possibility of shared transport site(s) for bile salts and methotrexate. Influx of the naturally occurring folate, 5-methyltetrahydrofolate, is also inhibited by the bile salts and bromosulfophthalein, although to a lesser extent than influx of methotrexate. Cholate and taurocholate reduce not only methotrexate influx but also the net level of intracellular methotrexate accumulation, with a proportional reduction in the synthesis of methotrexate polyglutamate derivatives. Deoxycholate and bromosulfophthalein inhibit methotrexate polyglutamate synthesis to a greater extent than inhibition of total drug uptake. The presence of albumin in the buffer markedly reduces bromosulfophthalein inhibition of MTX influx, but has a much lesser effect on taurocholate inhibition of methotrexate influx, presumably related to the much higher affinity of albumin for bromosulfophthalein than for taurocholate. These studies suggest that the level of bile salts in the hepatic sinusoids under physiological conditions may influence uptake and accumulation of methotrexate and its polyglutamate derivatives in hepatic parenchymal cells and may, therefore, influence the potential of this agent for producing hepatotoxicity in chemotherapeutic regimens. This raises the possibility that alterations in this interaction, in terms of regulation of bile salt pool size or time of administration of methotrexate relative to meals, may yield useful approaches for reducing methotrexate accumulation and metabolism in the liver and thereby minimize methotrexate hepatotoxicity especially in long-term low-dose regimens.
Attitudes toward breast-feeding and infant feeding among Iranian, Afghan, and Southeast Asian immigrant women in the United States: implications for health and nutrition education.

A nutritionist analyzed data on 150 immigrant mothers living in California but from Iran Afghanistan Vietnam Cambodia or Laos who had participated in or were eligible for WIC (Women Infants and Children) a US supplemental food program to examine cultural and socioeconomic factors linked with breast feeding practices. 95% of the mothers had exclusively breast fed their infants in their countries compared to 32% after they arrived in the US> In fact 85% exclusively breast fed for at least 5 months in their countries whereas only 14% did so after coming to the US> Further after immigrating to the US 38% fed their infants both breast milk and formula. Moreover 30% only offered their infants formula. In the US 82% of Iranian mothers exclusively breast fed their infants compared to 42% of Afghan mothers 14% of Vietnamese mothers 19% of Laotian mothers and 9% of Cambodian mothers (p Mothers who exclusively breast fed their infants reported breast feeding to be more advantageous than the other groups (p<.05). The cited advantages included bonding best food for infant protection against infection and successful breast feeding in the past. Mothers who partially or exclusively used formula were more likely to have returned to school had problems with the infants presence consider bottle feeding to be convenient received free formula and state economic reasons. Further those who exclusively breast fed were more likely to 1st breast feed their infant in the delivery room than were the other mothers (p<.01). These results indicated that economic reasons were the main reason for not breast feeding. Besides US health care providers in the hospital or those involved in WIC did not provide substantial support for breast feeding. Sound recommendations concluded this report.
Microvascular rarefaction and tissue vascular resistance in hypertension

The purpose of this study was to quantitatively estimate the relative contribution of arteriolar rarefaction (disappearance of microvessels) and arteriolar constriction to the increases in total pe...
A radicle solution: morphology and biomechanics of the Eucalyptocrinites ‘root’ system

Eucalyptocrinites is one the most common and familiar mid-Palaeozoic crinoids and is the exemplar of a form with dendritic radicular holdfasts. American museums have hundreds of specimens of Eucalyptocrinites holdfasts from the Silurian Waldron Shale of Indiana and Kentucky, USA. The radix (‘root’) system of Eucalyptocrinites can be described as comprised of links (branches) that meet at nodes. Measured values include the x- and y-coordinates of the nodes, the distances of the nodes from the stem, the angles between branches, branch length and branch width. Rose diagrams show clearly that the root systems are not isotropic but have preferred orientations. Branch angles are highly variable, but cluster around 60 degrees. Branch lengths and distal branch widths are relatively constant, but branch width increases variably towards the column. The branching pattern can be modelled as a self-similar (‘fractal’) structure. Several specimens labelled as Eucalyptocrinites show a distinct fivefold symmetry without branching and very likely represent a different taxon. The Eucalyptocrinites radix system, along with the probably stiff dististele, most likely functioned as a rigid plate that resisted rotational forces due to currents acting on the crown. Upstream radicles experienced tension, whereas downstream roots were compressed. This force distribution may explain the observed anisotropies in radix morphology. The ‘roots’ of Eucalyptocrinites and other crinoids have long been compared with the root systems of plants. Although there are superficial similarities, there are fundamental differences.
Optimal leader allocation in UAV formation pairs under no-cost switching

This paper considers a group of UAVs that travel from origin to destination locations. Individual agents can choose to either fly directly to their destination or pair with other agents into a leader-follower formation to conserve fuel. In the latter case, only the follower experiences a cost benefit, and hence UAVs must negotiate how to fairly allocate the task of leading. We show that selfish agents cannot reach satisfactory collaboration agreements, which leads us to propose the notion of e-cooperativeness. For this class of UAVs, we introduce the partition refinement algorithm to strategically schedule alternating leading and following intervals that induce cooperation. We show that the proposed strategy is guaranteed to find leader allocations with the minimum number of leader-follower switches. Moreover, these allocations are optimal with regards to the cost that UAVs can attain while collaborating with other UAVs. Several simulations illustrate our results.
“Deafness” effects in detecting alterations to auditory feedback during sequence production

Past research has shown that when discrete responses are associated with a perceptual goal, performers may have difficulty detecting stimuli that are commensurate with that goal. Three experiments are reported here that test whether such effects extend to sequence production. In Experiment 1, participants performed 8-note melodies repeatedly, and on each trial a single tone could be altered with respect to its pitch and/or synchrony with actions. Results suggested a selective deficit of detection when feedback pitch was unchanged and the event was slightly delayed. Experiment 2 showed that this "deafness" to feedback is limited to rhythmic motor tasks that require sequencing, in that similar effects did not emerge when participants produced pitch sequences by tapping a single key repeatedly. A third experiment demonstrated similar results to Experiment 1 when the mapping of keys to pitches on the keyboard was reversed. Taken together, results suggest a selective deafness to response-congruent delayed feedback, consistent with the idea that performers suppress previously planned events during production.
Attitudes and behavior of college students relative to oral-genital sexuality

A survey was conducted to determine college students' attitudes toward and behavior relative to oral-genital sexuality. Information concerning attitude and behavior was elicited through the use of an equal-interval attitude scale and a behavior inventory. Responses from 91 students were analyzed. Results of the study indicated that more favorable attitudes toward oral-genital sexuality were expressed by students who had participated in the specific behavior and by students who had experienced sexual intercourse. Attitude toward receiving oral-genital contact was found to be dependent on church attendance. Men were more likely than women to have received oral-genital contact, and students who had participated in sexual intercourse were more likely to have both administered and received oral-genital contact. Receiving oral-genital contact was dependent on church attendance. Women were more likely than men to require love as a prerequisite for their participation in oral-genital contact.
Randomized trial of preinduction cervical ripening: misoprostol vs oxytocin

Objective The purpose of this study was to compare the vaginal delivery rate in women who undergo labor induction with preinduction misoprostol or oxytocin alone. Study Design Women with singleton pregnancies and Bishop scores Results One hundred sixty-three women received oxytocin, and 164 women received misoprostol. Maternal demographics, pretreatment Bishop scores, and labor analgesia were similar between groups. Vaginal delivery rates were also similar: 87% (n = 141) for oxytocin and 81% (n = 133) for misoprostol. Mean time from treatment to delivery was shorter for the oxytocin group, compared with the misoprostol group (13.1 vs 16.3 hours; P = .005). There was no difference in maternal complications or neonatal outcomes between groups. Conclusion Preinduction cervical ripening with misoprostol did not improve the vaginal delivery rate and resulted in longer intervals to active labor and delivery. Preinduction cervical ripening with misoprostol may not be necessary.
Distance-transitive graphs and generalized polygons

On etablit un theoreme sur un graphe Γ connexe, regulier de valence k≥3, circonference finie g, avec s≥4. Γ est (G,s)-transitif pour G≤aut(Γ) tel que G(x) est fini pour chaque sommet x
Ricin inhibition of in vivo protein-synthesis in castor beans

Abstract Ricin is a potent inhibitor of protein-synthesis by 80 S ribosomes. Experiments in vitro have previously shown that ribosomes from castor bean endosperm, the source of ricin, are just as susceptible to inhibition as ribosomes from other plants. Studies in vivo with castor bean endosperm have now shown that exogenously applied ricin enters the cells and inhibits the incorporation of [14C] leucine into protein. Ricin did not affect the uptake of [14C] leucine. Galactose and lactose prevented the inhibition of protein-synthesis by ricin by interfering with its uptake. This indicated that ricin entered the cells by a mechanism similar to that in animal cells, by interaction of the B-chain with a receptor. The data from experiments in vivo support the conclusion drawn from the data obtained in vitro, that compartmentation of endogenous ricin within protein bodies/vacuoles protects cytoplasmic protein-synthesis in the endosperm during germination.
Estimates for pollution profiles above finite area-sources

Abstract A theoretical basis is presented for an integral-equation method of describing airborne pollution concentrations above an arbitrary area-source and for arbitrary air-surface exchange. The method is then used to describe concentrations of pesticides above a treated field, and the predicted profiles are used to interpret recently reported data. For this case, different profiles can result from different fetch-dependent source strengths, in turn dictated by each pesticide's air/surface partition coefficient.
THE ESSENTIAL AND THE ACCIDENTAL

The distinction between the essential and the accidental is nearly always understood in modal terms. After criticizing some recent writings by Kit Fine that question that understanding, I develop a theory according to which whether a given feature of a thing is essential turns on whether it is explained by other features of that thing. The theory differs from the modal view by leaving room for features that are accidental even though their bearers cannot exist without them. The theory has the additional advantage of being open to the results of scientific theory.
Efficacy and Physiological Responses of Grass Carp to Different Sedation Techniques: I. Effects of Various Chemicals on Sedation and Blood Chemistry

Abstract Grass carp Ctenopharyngodon idella are commonly used as a low cost, biological control for aquatic vegetation in aquaculture ponds and other private and public waters. In order to minimize the risk of establishing self-sustaining populations in U.S. waters, many states now require grass carp be certified as triploid prior to sale and stocking. To facilitate ploidy testing, grass carp are typically sedated before collecting blood samples. Chemical sedatives such as tricaine methanesulfonate (MS-222) and carbon dioxide (CO2) are most commonly used to sedate fish, but there is increasing interest in other chemical sedatives such as benzocaine and eugenol. We evaluated time to induction to Stage IV sedation and recovery, survival, and postsedation blood chemistry of grass carp (301 ± 8 g, mean ± SE) sedated with MS-222 (150 mg/L), benzocaine (150 mg/L), eugenol (60 mg/L), or CO2 (∼400 mg/L). Induction times for all sedatives excluding CO2 (14.9 min) were less than 2.4 min (range, 1.5–2.4 min). Averag...
Comparison of measurement of dialkyl phosphates in milk/urine and blood cholinesterase and insecticide concentrations in goats exposed to the organophosphate insecticide, imidan

Recognition of exposure to imidan was assessed in goats by dialkyl phosphate concentrations, blood cholinesterase (ChE) determinations, and blood imidan concentrations. Groups of three goats received 5.0 mg imidan/kg/day (low dose) or 10 mg imidan/kg/day (high dose) for 7 days orally. One goat received no imidan and one goat received an acute single dose (200 mg/kg). The urine of all treated goats was examined for the excretory dialkyl phosphates, O,O-dimethyl phosphorodithioate (DMDTP) and O,O-dimethyl phosphorothionate (DMTP). The overall mean DMDTP urinary concentration was 19.1 ppm (10-mg/kg treatment group) and 7.2 ppm (5-mg/kg treatment group). These metabolites rapidly disappeared following removal of the treatment except in those goats clinically affected. Milk contained no identifiable concentrations of dialkyl phosphates. Cholinesterase depression was observed in all imidan-treated goats, and a dose effect was observed. No imidan was detected in whole blood of either the 5- or 10-mg/kg treatment groups. Low blood concentrations (ppb) of imidan were measured in the acute single-dose exposed goat. Both urinary DMDTP and blood ChE provided recognition of imidan exposure. DMDTP, however, was immediately present in urine after exposure and provided stronger support for organophosphate exposure than did blood ChE.
The effect of segregated transition metal ions on the grain boundary resistivity of gadolinium doped ceria: Alteration of the space charge potential

Abstract The effect of segregated transition metals on the grain boundary resistivity of 1 mol% Gd-doped ceria has been investigated. The main focus of interest is whether the space charge potential that causes the blocking effect of the grain boundaries of the ceria can be extrinsically modified. The introduction of a small amount (
Excitation of Helium Atoms by Positron Impact

Excitation cross sections for positrons of energies up to 10 eV above threshold scattered in the forward direction by helium atoms have been measured directly by use of time-of-flight spectrometry. The results indicate that the scattering is dominated by excitation of the $2^{1}S$ state and that there exists a strong small-angle lobe in the angular distribution of the scattered positrons.
Mechanism of healing of the human prostatic urethra following thermal injury

Abstract Objectives . To characterize histopathologically the healing response of the prostatic urethra after laser thermal coagulation and standard transurethral resection of the prostate (TURP). Methods . The study included 31 patients who underwent radical prostatectomy because of malignancy. Twenty-two (first group) had laser radiation either at the time of surgery (18 patients) or from 1 to 12 weeks prior to prostatectomy (4 patients). Nine patients (second group) had TURP from 6 to 96 weeks prior to prostatectomy. Results . Coagulation necrosis followed by sloughing was observed during the first 10 weeks after laser radiation. After the first 10 weeks, the healing response was otherwise stereotypical and comparable for both groups of patients. Re-epithelialization was prominent and resulted from migration of proliferating epithelial cells from the remaining acinar and ductal epithelium. Squamous metaplasia was conspicuous and present indefinitely. Development of inflammatory reaction followed by granulation tissue and well-organized fibroblastic stroma were sequentially recognized, but less prominent. Complete re-epithelialization and wound sealing was not observed before the first 12 weeks of healing. Conclusions . Our study suggests that laser thermal coagulation and TURP are partial-thickness injuries.Because of the abundant germinal epithelium in the remaining prostatic glands and ducts, the healing response of the prostatic urethra is relatively unimpeded and free of contractures, analogous to second-degree skin burns.
Emulsion electrospinning: composite fibers from drop breakup during electrospinning

We evaluate the feasibility of electrospinning oil-in-water type emulsions. The emulsions had an aqueous solution of polyethylene oxide (PEO) as the continuous phase, and either mineral oil or a polystyrene (PS) in toluene solution as the drop phase. The Taylor cones and electrified liquid jets were stable even when the emulsion drops were as large as a few-ten microns in diameter. The resulting electrospun PEO fibers incorporated the dispersed phase of the emulsion in the form of drops (in case of mineral oil), or in the form of solid particles (in case of PS). Mineral oil drops appear to be completely encapsulated in the PEO fibers, whereas the PS particles are either incompletely encapsulated, or covered by only a very thin layer of PEO. Calculations show that in both cases, the initially large emulsion drops are broken during the electrospinning process. Copyright © 2007 John Wiley & Sons, Ltd.
Loss and recovery of phenotypic expression of gross leukaemia virus

A RECENT theory of the viral induction of cancer1–3 postulates that determinants of oncogenic viruses can be carried permanently by cells of many vertebrates, either overtly or covertly. Several organismic and environmental factors can then “switch on” and “switch off” the expression of viruses. Thus the C-type RNA tumour viruses appear to be perhaps completely or incompletely expressed and are directly associated with leukaemias and sarcomas of fowls, rodents and felines. This article describes a system in which the expression of Gross leukaemia virus (GLV) in rat leukaemic cells was successively lost and recovered by alternate passages in vivo and in vitro.
Using Spreadsheets in Population Geography Classes.

Abstract The availability of good software for microcomputers is enhancing the ways course materials are being presented on college campuses. In population geography, the spreadsheet program is especially useful. Spreadsheet programs are easy to learn and are well suited for manipulating numbers representing demographic variables in population geography courses. Spreadsheet programs provide a framework for numeric data entry and interactive computations. The programming steps used to solve a problem can be saved as a macro. Data entry and processing can be simplified by the use of templates. In addition, large data sets already in digital form can be imported directly without the need for manual entry. Spreadsheet programs are thus quite flexible in their number handling capabilities. A sample template and macro for a population geography class are given.
SOLUTIONS OF THE STATIC THEORY INTEGRAL EQUATIONS FOR PION-NUCLEON SCATTERING IN THE ONE-MESON APPROXIMATION

Numerical solutions of the one-meson approximation of the Low equations for elastic pion-nucleon scattering in the fixed-nucleon, extended-source theory are obtained with a Gaussian cutoff function. The validity of the method requires that the scattering amplitudes have no zeros in the complex plane other than at z = plus or minus 1. The functions obtained for the (3,3) and (1,1) states satisfy the Low equations within the accuracy of the method, but the (1,3) and (3,1) states are only approximately given. This difficulty with the (1,3) and (3,1) states is correlated with the development of a zero in the corresponding scattering amplitude well before physically interesting values of the parameters (coupling constant and cutoff) are reached. A best fit to the (3,3)-state data up to 170-Mev pion laboratory energy requires a coupling constant, f/sup 2/, less than 0.08. The solution is consistent with the (3,1)- state data, but gives a (1,1)-state phase shift of larger magnitude than experiment appears to permit. It is found that the cutoff function does not prevent strong interactions at very high energies. Their occurrence appears to be a property of the static model. The contributions of such interactions to various static-theory calculations is briefiy discussed.more » It is shown that in the p-wave part of the relativistic dispersion relations, where there is no cutoff function, if use is made of the low-energy data, then the very high-energy contributions of the static theory are replaced by recoil terms of order mu /M. (auth)« less
Data on total and spectral solar irradiance

This paper presents a brief survey of the data available on solar constant and extraterrestrial solar spectral irradiance. The spectral distribution of solar radiation at ground surface, computed from extraterrestrial solar spectral irradiance for several air mass values and for four levels of atmospheric pollution, is also presented. The total irradiance at ground level is obtained by integration of the area under the spectral irradiance curves. It is significant that, as air mass increases or as turbidity increases, the amount of energy in the infrared relative to the total increases and that the energy in the UV and visible decreases.
The Reaction of Coumalic Acid with Benzoquinone: Formation of a Spirobutenolide

Abstract Although additions of α-pyrones to dienophiles have received extensive study,1 there have been few reports of additions of α-pyrones to quinones.2 In attempts to add benzoquinone (1) to coumalic acid (2), we have found that keeping these compounds in methanol and acetic acid in the presence of sodium acetate for 4 hours at 0°C followed by removal of the solvents under reduced pressure and purification by flash chromatography gave compound 3 3 (22%4) mp 158–161°C raised to mp 160–162°C (benzene) UV (MeOH) λ;306 nm (∊ 4700), 215 (12,500); IR (CHCl3) vmax 3340, 1770 cm−1; 1H NMR ((CD3)2CO) δ 3.5 (s, 3H), 5.52 (s, 1H), 6.35 (d, J=5 Hz, 1H), 6.55 (m, 1H), 6.85 (m, 2H), 7.55 (d, J=5 Hz, 1H); 13C 171.5, 153.8, 153.4, 150.9, 122.3, 121.8, 119.6, 111.8, 110.8, 94.7, 56.9; mass specteum m/e (relative intensity) 234.0530 (54), 202.0267 (100), 174.0320 (34), 146.0367 (88), 98.0371 (47); m/e calcd for C12H10O5.
Function Generation With Finitely Separated Precision Points Using Geometric Constraint Programming

This paper extends geometric constraint programming (GCP) to function generation problems involving large numbers of finitely separated precision points and complex mechanisms. In parametric design software, GCP uses the sketching mode to graphically impose geometric constraints in kinematic diagrams and the numerical solvers to solve the relevant nonlinear equations without the user explicitly formulating them. For function generation, the same approach can be applied to any mechanism, requiring no unique algorithms. Implementation is straightforward, so the designer can quickly generate solutions for a large number of precision points and/or with complex mechanisms to accurately match the function. Examples of function generation with a four-bar linkage, a Stephenson III six-bar linkage, and a seven-bar linkage with a mobility of two are presented.
Predictors of first discharge and subsequent survival in patients with automatic implantable cardioverter-defibrillators.

BACKGROUNDTwo hundred eighteen patients were evaluated in a two-phase approach (time to first appropriate discharge, survival after discharge) to identify factors that may be related to maximal benefit derived from use of an automatic implantable cardioverter-defibrillator (AICD).METHODS AND RESULTSOne hundred ninety-seven patients survived implantation of AICD, with or without concomitant cardiac surgery. One hundred five patients had an AICD discharge associated with syncope, presyncope, documented sustained ventricular tachycardia or fibrillation, or sleep at 9.1 +/- 11.1 months after implantation. Patients survived 23.8 +/- 18.0 months after AICD discharge. Left ventricular dysfunction (p = 0.008 for ejection fraction less than 25%) was associated with earlier AICD discharge and shortened survival after AICD discharge (p = 0.008 for ejection fraction less than 25%; p = 0.01 for New York Heart Association functional class III and IV). beta-Blocker administration (p = 0.006) and coronary bypass surgery ...
A directional fast neutron detector using scintillating fibers and an intensified CCD camera system

Abstract We have been developing and testing a scintillating fiber detector (SFD) for use as a fast neutron sensor which can discriminate against neutrons entering at angles non-parallel to the fiber axis (“directionality”). The detector/convertor component is a fiber bundle constructed of plastic scintillating fibers each measuring 10 cm long and either 0.3 mm or 0.5 mm in diameter. Extensive Monte Carlo simulations were made to optimize the bundle response to a range of fast neutron energies and to intense fluxes of high energy gamma-rays. The bundle is coupled to a set of gamma-ray insensitive electro-optic intensifiers whose output is viewed by a CCD camera directly coupled to the intensifiers. Two types of CCD cameras were utilized: 1) a standard, interline RS-170 camera with electronic shuttering and 2) a high-speed (up to 850 frame/s) field-transfer camera. Measurements of the neutron detection efficiency and directionality were made using 14 MeV neutrons, and the response to gamma-rays was performed using intense fluxes from radioisotopic sources (up to 20 R/h). Recently, the detector was constructed and tested using a large 10 cm by 10 cm square fiber bundle coupled to a 10 cm diameter GEN I intensifier tube. We present a description of the various detector systems and report the results of experimental tests.
New production in the North Atlantic derived from seasonal patterns of surface chlorophyll

Abstract Annual new production resulting from winter nitrate has been estimated for the North Atlantic using data from the Coastal Zone Color Scanner (CZCS) between 1979 and 1983. Twelve monthly mean surface chlorophyll images, based on 5-year averages of CZCS data, were used to identify three zones with distinct seasonal patterns. A mid-latitude zone, with an area of 7 × 106 km2, exhibited a spring bloom followed by oligotrophic conditions at the surface throughout the summer. The decline in surface chlorophyll following the spring bloom was assumed to indicate that winter nitrate in the mixed layer was exhausted and that a nitracline had formed at depth. Based on observations by Strass and Woods (Deep-Sea Research, 38, 35–56, 1991) in the North Atlantic, we estimate that the nitracline deepened at a rate of 10 m per month, starting at the base of the mixed layer. By determining the timing of the onset of oligotrophic conditions from the satellite data, we can estimate the volume of nitrate-depleted water lying above the nitracline in late summer. This was combined with an estimate of the nitrate concentration at the start of the growing season to derive new production. The model for the initial nitrate concentration is based on an empirical relationship between winter nitrate from Glover and Brewer (Deep-Sea Research, 35, 1525–1546, 1988) and the maximum chlorophyll at the end of the spring bloom. The resulting new production was 24 g C m−2 y−1 (4.2 g N m−2 y−1) in this mid-latitude transitional zone. Applying the same method to subtropical zone of approximately equal area yields an estimate of new production of 18 g C m−2 y−1 (3.1 g N m−2 y−1); the area-weighted average for both zones was 21 g C m−2 y−1 (3.7 g N m−2 y−1). In the subtropical zone, the maximum chlorophyll occurred in the winter and the minimum in late summer, suggesting that production was nutrient-limited throughout the year. The third smaller zone (2.5 × 106 km2) was located in subpolar regions to the north, where surface chlorophyll was minimum in winter and maximum in late summer. Assuming that all winter nitrate had been assimilated by the end of the summer within the upper 40 m of the water column in this zone, new production is estimated to be 43 g C m−2 y−1 (7.6 g N m−2 y−1). Our results underestimate new production because they are based solely on winter nitrate assimilated by phytoplankton between winter and late summer. Nevertheless, the values are comparable in magnitude to previous estimates of total productivity in oligotrophic oceanic regions ( Koblentz-Mishke et al., in Scientific exploration of the South Pacific, W.S. Wooster , editor, pp 183–193, 1970).
Acoustic loads on an externally blown flap system due to impingement of a TF‐34 jet engine exhaust

One of the techniques being investigated in the studies of powered‐lift augmentation of aircraft is the use of externally blown flaps. When the flaps deploy, the exhaust of the engine directly impinges on them and is directed downward, providing additional lift. Because of this direct impingement on the flap surface, severe dynamic loads may be induced on the flap elements. To obtain data on these surface loads, a section of a wing and triple‐slotted flap system was mounted behind a TF‐34 jet engine (nominal thrust of 7000 lb). Fluctuating pressure in the range from 20 to 10 000 Hz, temperature, and static pressure measurements were made at several locations over the span and chord of the second and third flap elements for a typical takeoff flap angle setting—0°, 20°, 40°—and a typical landing flap angle setting—15°, 35°, 55°. The effect of engine power setting was also investigated. The wing and flap sections were of boiler plate construction to minimize the effect of the structural response on the loads measurements. Data are presented showing the overall fluctuating pressure levels and power spectral densities as a function of engine performance. The maximum fluctuating pressures reached levels of 165 dB on the flaps. The spatial distributions of the loads are also presented and discussed. Some comparisons with previous results are discussed.
A Complicated “Simple” Renal Cyst

Background:Simple renal cysts are usually asymptomatic and benign. Rarely, symptoms and complications can develop from local mass effect which is illustrated by this case.Case Presentation:77 year old Caucasian male presents with abdominal pain for five days. Abdominal exam was diffusely tender, markedly distended, tympanic with absent bowel sounds. His work-up included an abdominal x-ray showing a colonic obstruction and abdominal CT showing a large 27 cm renal cyst. Drainage of the renal cyst resolved obstructive symptoms.Conclusion:A simple renal cyst should not be overlooked as the reason for acute abdominal pain. Simple renal cysts, though benign are not without complications.
Alterations in blood pressure and REM sleep after pontine carbachol microinfusion

Abstract Infusions of cholinomimetics, either systemically in normal humans, or directly into the brain stem of unanesthetized cats and rats, readily induce rapid eye-movement (REM) sleep. In anesthetized cats and rats, infusions of cholinomimetics have been shown to produce both increases and decreases in arterial blood pressure. We determined the relation of these blood pressure changes to REM sleep, by examining both blood pressure and sleep states after injecting carbachol at midbrain, pontine, and medullary sites in unanesthetized cats. In the pons, carbachol infusions produced an early decrease in blood pressure followed by a sustained hypertensive effect. The early blood pressure decrease was associated with the occurrence of REM sleep; however, higher values were associated with later REM sleep episodes. In other brain stem sites carbachol did not produced REM sleep or its associated reductions in blood pressure. Instead it produced a hypertensive response that increased throughout the 1-h observation period. We hypothesize that pontine muscarinic mechanisms trigger REM sleep and a REM sleep-associated decrease in blood pressure. Thereafter, nicotinic receptors mediating the blood pressure increase override the muscarinic-induced decrease.
Which Modeling Scholars Get Promoted, and How Fast?

The future of quantitative marketing is defined by its research output as much as by the researchers who produce it. Yet, little is known about the determinants of promotion and time to promotion among quantitative marketing scholars (or “modelers”) as well as whether their early signals of attractiveness in the job market are indicative of future success. In this article, we shed light on these issues by investigating the roles that research productivity, departmental characteristics, demographics, and coauthorship play in determining promotion and time to promotion from assistant to associate professor. We find that early signals of attractiveness do not play an important role in determining modelers’ promotion and time to promotion. Research productivity does, and its effect is moderated by whether modelers are employed in departments that offer Ph.D. programs. We also find that membership in various coauthorship social networks, or “communities”, is a robust predictor of promotion and time to promotion.
Mechanical Properties of Rat Cardiac Muscle during Experimental Hypertrophy

The mechanical properties of trabecular muscles from the hearts of 77 rats subjected to aortic arch constriction were compared with those from 77 unoperated and sham-operated control animals at 1, 3, 7, 14, and 28 days after operation. Significant hypertrophy, as evidenced by an increase in left ventricle to body weight ratio, was first seen at three days ( P < 0.02), reached a maximum of 30 to 40% by seven days ( P < 0.001), and remained relatively constant throughout the remainder of the experiment. Depression of isotonic shortening velocity and maximum isometric force of trabecular muscles from hypertrophied hearts was first seen at seven days. These changes persisted at 14 and 28 days. When alterations in muscle mechanics due to changes in muscle thickness were taken into consideration, muscles from hypertrophied hearts demonstrated a depressed maximum velocity of shortening ( P < 0.001), while development of isometric tension was unaltered. The latter appeared to be maintained at least in part by a prolonged contraction time, as reflected by increases in the time to peak isometric tension ( P < 0.05) and the time to peak "unloaded" isotonic shortening ( P < 0.001). Resting tension was increased in trabecular muscles from hypertrophied hearts. Tissue hydroxyproline concentration was elevated with hypertrophy. The observed depression in muscle shortening velocity at light loads may be explained by altered contractile state or by increased stiffness of the parallel elastic element.
Pyruvate kinase substrate activity exhibited by homologs of phosphoenolpyruvate.

Abstract Rabbit muscle pyruvate kinase (EC 2.7.1.40) was found to utilize three homologs of P-enolpyruvate as substrates. These were P-enol-α-ketobutyrate, P-enol-α-ketovalerate and P-enol-α-ketocaproate. The Michaelis constants of these compounds are 2.13 × 10 −5 M, 1.66 × 10 −4 M and 1.97 × 10 −3 M, respectively. The velocity of the enzyme acting on these compounds, relative to P-enolpyruvate was 0.16%, P-enol-α-ketobutyrate; 0.29%, P-enol-α-ketovalerate; 0.13%, P-enol-α-ketocaproate.
A complex protein assembly catalyzes polyadenylation of mRNA precursors.

Abstract Nearly every eukaryotic mRNA contains a poly(A) tail at its 3′ end. Unlike the factors that catalyze other RNA processing reactions, the basal polyadenylation machinery consist entirely of proteins. As with other steps in gene expression, however, this machinery is complex, consisting of multiple separable factors. Two multisubunit factors are required for specification of the poly(A) site and formation of a stable protein—RNA complex. Two additional proteins, as well as poly(A) polymerase, join the complex and are required for cleavage of the pre-mRNA and synthesis of the poly(A) tail, respectively. These and other properties suggest at least a superficial similarity between transcription initiation and polyadenylation.
Potentials of mean force with ab initio mixed Hamiltonian models of solvation

Abstract We give an account of a computationally tractable and efficient procedure for the calculation of potentials of mean force using mixed Hamiltonian models of electronic structure where quantum subsystems are described with computationally intensive ab initio wavefunctions. The mixed Hamiltonian is mapped into an all-classical Hamiltonian that is amenable to a thermodynamic perturbation treatment for the calculation of free energies. A small number of statistically uncorrelated (solute–solvent) configurations are selected from the Monte Carlo random walk generated with the all-classical Hamiltonian approximation. Those are used in the averaging of the free energy using the mixed quantum/classical Hamiltonian. The methodology is illustrated for the micro-solvated SN2 substitution reaction of methyl chloride by hydroxide. We also compare the potential of mean force calculated with the above protocol with an approximate formalism, one in which the potential of mean force calculated with the all-classical Hamiltonian is simply added to the energy of the isolated (non-solvated) solute along the reaction path. Interestingly the latter approach is found to be in semi-quantitative agreement with the full mixed Hamiltonian approximation.
On the Vulnerabilities of CSI in MIMO Wireless Communication Systems

Multiple-input multiple-output (MIMO) technologies are a popular choice for emerging wireless systems due to their promised gains in throughput and reliability. In order to realize any gains over traditional non-MIMO communication systems, these systems must possess accurate knowledge of the wireless channel. In this paper, we investigate strategies for disrupting MIMO communications by developing attacks that target the often overlooked, but essential, channel estimation procedure. Our study focuses on the two most popular and well-known MIMO techniques: the capacity achieving SVD-based MIMO scheme, and the Alamouti space-time block code (STBC), which spans many protocols including 802.11n, WiMAX, and 3GPP. We augment theoretical and simulation results with real-world experimentation using the USRP/GNU Radio software defined radio platform. We also present novel methodology to protect the channel estimation procedure from such attacks by embedding authentication messages into physical layer features of the transmissions.
Grassroots Expectations of Democracy and Economy: Argentina in Comparative Perspective. By Nancy R. Powers. Pittsburgh: University of Pittsburgh Press, 2001. 294p. $45.00 cloth, $19.95 paper.

As the recent political meltdowns in Venezuela and Argentina made clear, a vast gap persists between elite behavior and mass attitudes in much of Latin America. Scholarly understanding of this gap—and its political implications—would benefit from more fine-grained, yet theoretically informed, studies of nonelites. Nancy Powers's Grassroots Expectations of Democracy and Economy is one such study. Drawing on in-depth interviews with 41 residents of two lower-income neighborhoods in Argentina's federal capital, Powers examines how poor people understand their own interests. She argues that people experience poverty in vastly different ways, and this variation has important implications for political behavior. Thus, to understand how poor people view the relationship between their own material conditions and government policy, one must examine “the conditions themselves and how people live with them” (p. 33). This kind of inductive analysis has important and well-known limitations, particularly for studies—such as this one—based on a small sample size. Yet given how little we continue to know about the relationship between mass attitudes and macrolevel politics in Latin America, such a “bottom up” approach should be welcomed. To the extent that fine-grained inductive research generates insights that 1) are unlikely to emerge out of larger-n studies and 2) challenge or refine dominant theoretical assumptions, it can be extremely fruitful. This is the case with important sections of the book.