cssi/SciSciGPT-SciSciNet huggingface dataset:
Discrete Morse functions, vector fields, and homological sequences on trees

We construct a discrete Morse function which induces both a specified gradient vector field and homological sequence on a given tree. After reviewing the basics of discrete Morse theory, we provide an algorithm to construct a discrete Morse function on a tree inducing a desired gradient vector field and homological sequence. We prove that our algorithm is correct, and conclude with an example to illustrate its use.
Distributed stimulation increases force elicited with functional electrical stimulation.

Objective The maximum muscle forces that can be evoked using functional electrical stimulation (FES) are relatively modest. The reason for this weakness is not fully understood but could be partly related to the widespread distribution of motor nerve branches within muscle. As such, a single stimulating electrode (as is conventionally used) may be incapable of activating the entire array of motor axons supplying a muscle. Therefore, the objective of this study was to determine whether stimulating a muscle with more than one source of current could boost force above that achievable with a single source. Approach We compared the maximum isometric forces that could be evoked in the anterior deltoid of anesthetized monkeys using one or two intramuscular electrodes. We also evaluated whether temporally interleaved stimulation between two electrodes might reduce fatigue during prolonged activity compared to synchronized stimulation through two electrodes. Main results We found that dual electrode stimulation consistently produced greater force (~50% greater on average) than maximal stimulation with single electrodes. No differences, however, were found in the fatigue responses using interleaved versus synchronized stimulation. Significance It seems reasonable to consider using multi-electrode stimulation to augment the force-generating capacity of muscles and thereby increase the utility of FES systems.
Targeting extracellular matrix stiffness to attenuate disease: From molecular mechanisms to clinical trials

Tissues stiffen during aging and during the pathological progression of cancer, fibrosis, and cardiovascular disease. Extracellular matrix stiffness is emerging as a prominent mechanical cue that precedes disease and drives its progression by altering cellular behaviors. Targeting extracellular matrix mechanics, by preventing or reversing tissue stiffening or interrupting the cellular response, is a therapeutic approach with clinical potential. Major drivers of changes to the mechanical properties of the extracellular matrix include phenotypically converted myofibroblasts, transforming growth factor β (TGFβ), and matrix cross-linking. Potential pharmacological interventions to overcome extracellular matrix stiffening are emerging clinically. Aside from targeting stiffening directly, alternative approaches to mitigate the effects of increased matrix stiffness aim to identify and inhibit the downstream cellular response to matrix stiffness. Therapeutic interventions that target tissue stiffening are discussed in the context of their limitations, preclinical drug development efforts, and clinical trials.
Surgeon-performed ultrasound for the assessment of parotid masses.

Abstract Background Studies on parotid gland ultrasound assessments performed specifically by surgeons are seldom reported. Methods Retrospective series of a single academic surgeon experience, analyzing 70 new parotid masses with evaluable preoperative SP-US characteristics, location measurements, and perioperative events. Results 31/70 masses were malignant. SP-US characteristics significantly associated with both malignancy and positive margins included extraparenchymal extension, irregular borders, hypervascularity, infiltration, and the lack of deep enhancement. The larger the skin-to-deep-aspect-of-tumor distance, the more likely the tumor was deep to FN. For the 39 cytologically benign tumors, neither CT nor MRI provided additional information to change management except for full delineation of parapharyngeal space extension in 2 cases. Conclusion SP-US can help predict parotid mass benignity/malignancy, positive margin risk, and tumor relation to FN. SP-US may be used as the sole imaging in cytologically benign tumors unless the deep tumor extent cannot be identified.
Unilateral lung agenesis, hiatal hernia and atrioventricular septal defect: a rare combination of congenital anomalies.

Unilateral lung agenesis is a relatively rare congenital anomaly with a reported incidence of 1 in 15 000 births. It is frequently associated with other congenital malformations. Some of the sequelae of lung agenesis are potentially life-threatening. Here, we report a case of left lung agenesis in association with hiatal hernia and atrioventricular septal defect, a rare combination of anomalies which have not been described previously in the literature.
Proofs from The BOOK by Martin Aigner and Gunter M. Ziegler

(2000). Proofs from The BOOK by Martin Aigner and Gunter M. Ziegler. The American Mathematical Monthly: Vol. 107, No. 9, pp. 874-876.
Grain Boundary Processes in Pb-Sn Solders

ABSTRACT The cyclic deformation behavior in four Pb-Sn alloys of interest to the electronics industry has been investigated. The emphasis is on an understanding of the microstructural processes that occur during deformation. It is shown that grain boundary migration, sliding and cavitation at the grain boundaries are important processes that occur and contribute to failure in Pb-rich, Pb-Sn alloys. In as-cast Pb-Sn eutectic, failure processes initiate primarily at the inter-colony boundaries. The role of interfaces in governing fatigue behavior in these technologically important materials are highlighted.
The Role of Microaggregation in Hormone–Receptor–Effector Interactions

Publisher Summary The binding of a hormone, neurotransmitter, or other ligand that is active at very low concentrations to highly specific receptors is an interaction of fundamental importance for the regulation of cell function. It has become evident that the formation of a ligand–receptor complex is only the first step in a complex series of events that lead to the production of one or more second messengers. The intermediate steps include interaction with coupling factors, such as the activating and inhibitory coupling proteins that mediate the interaction between various receptors and adenylate cyclase or the dimerization of the receptor–hormone complex. Receptor dimerization is involved in the ability of antireceptor antibodies to mimic the biological actions of a number of hormones including some, such as insulin, for which the second messenger has not yet been identified. It analyzes the adenylate cyclase system in which a regulatory protein mediates the interactions between the receptor and the effector.
A Balanced Information Diet, Not Echo Chambers: Evidence From A Direct Measure of Media Exposure

Do citizens seek out political information in a biased and selective manner, that is do they primarily watch, listen and read information supporting their side? Or, are they balanced- information seekers, giving equal time to both sides of the argument? To adjudicate between these competing models of political exposure, I measure political exposure bias across two media environments using novel individual level longitudinal datasets. First, I attempt to replicate the large selective exposure effects found in Lazarsfeld’s 1940 panel study – designed to extensively measure voter’s exposure to the universe of campaign communications – political speeches, newspaper stories, radio newscasts, editorials, columns, magazine articles over the course of the 1940 U.S. presidential election. The second study leverages new behavioral data measuring selective exposure to TV and Radio newscasts during the 2006 Midterm Election. These data combine survey measures of political views with media tracking data that continuously and automatically log panelists’ 24/7 exposure to all radio and television programming over a 90 day period – (panelists’ cell phones pick up radio and TV sound which is matched against a database of programming) – resulting in 541, 892 observations for 920 panelists. Results are clear across media environment and platform: less than 5% of the electorate has a tendency to read, listen or watch to one’s own side. Rather the vast majority of citizens, consume centrist media, while tuning out news from ideological sources altogether. Of those who do turn to ideological sources, most have a balanced information diet – in that they consume news programming from both ends of the political spectrum. Contrary to recent claims depicting an electorate where powerful partisan loyalties bind citizens to their preferred ideological news sources, there is little evidence that selective exposure occurs on a sufficiently broad scale to affect deliberative democracy or contribute to mass polarization.
Kinetic Analysis of Unilateral Landings in Female Volleyball Players After a Dynamic and Combined Dynamic-Static Warm-up

Avedesian, JM, Judge, LW, Wang, H, and Dickin, DC. Kinetic analysis of unilateral landings in female volleyball players after a dynamic and combined dynamic-static warm-up. J Strength Cond Res 33(6): 1524-1533, 2019-A warm-up is an important period before training or competition to prepare an athlete for the physical demands of subsequent activity. Previous research has extensively focused on the effects of warm-up in relation to various jumping performance attributes; however, limited research has examined the biomechanical nature of landings after common warm-up practices. Twelve female, collegiate-level volleyball players performed unilateral landings on the dominant and nondominant limb before and after dynamic warm-ups and combined dynamic-static (CDS) warm-ups. Kinetic variables of interest were measured at the hip and knee during the landing phase of a volleyball-simulated jump-landing maneuver. A significant 3-way interaction (warm-up × limb × time) for peak internal knee adduction moment was observed, as this kinetic parameter significantly increased (p = 0.01; d = 0.79) in the nondominant limb at 1-minute post-CDS warm-up. No other warm-up differences were detected; however, significant main effects of limb were determined for dominant-limb internal hip abduction moment (p < 0.01; d = 1.32), dominant-knee internal rotation moment (p < 0.01; d = 1.88), and nondominant-knee external rotation moment (p < 0.01; d = 1.86), which may be due to altered hip and trunk mechanics during the jump landings. This information provides strength and conditioning professionals with biomechanical information to determine warm-up protocols that reduce the risk of injury in female volleyball athletes.
Resource Selection in Cognitive Networks With Spiking Neural Networks

This paper explores the feasibility of a spiking neural network-based approach to cognitive networking, that is potentially suitable for low-power neuromorphic chips. We discuss the design of a cognitive network controller (CNC), which can dynamically optimize the selection of resources for recurrent network tasks, based on both its assigned objectives and observations of the actual performance achieved by each resource. We present a coding strategy for the action decisions based on the time-to-fire of spikes, a learning algorithm, and a regulation method to keep synapse strengths within an adequate range. To evaluate the proposed method, we apply the CNC to a challenged network environment using simulation. In this scenario, the CNC requires to optimize the average file transfer time over a multichannel space communication link, which is available only for a time window because of orbital dynamics. Compared to conventional methods, we show that the CNC achieves its objective for a broad range of offered loads. We examine the impact of key system factors that include learning and space protocol parameters. The proposed CNC potentially fosters the development of new cognitive networking applications.
Patterns of Co-occurring Modes of Marijuana Use Among Colorado High School Students.

Abstract Purpose The purpose of the study was to understand how adolescents concurrently use different modes of marijuana consumption. Methods Using data from the 2017 Healthy Kids Colorado Survey, we examined how modes of marijuana use (smoking/ingesting/vaping/dabbing/other) co-occur. We estimated the prevalence of all combinations of these modes among adolescents who reported past 30-day marijuana use (n = 3,618). We then estimated the prevalence of any use of each mode by each mode usually used. Results Forty-one percent reported only smoking, another 10% reported smoking and dabbing, and 9.8% reported smoking and ingesting. Only about 10% used a combination of modes that did not include smoking. Smoking was the most common additional mode for all other usual modes of consumption. Conclusions Smoking in combination with dabbing and/or ingesting were the most common multimode patterns of use. Nearly all adolescents who use marijuana smoke some or most of the time.
Do clean energy (equity) investments add value to a portfolio

Investment in renewable energy needs to increase significantly to address climate change. Large institutional investors with huge asset bases, such as pension funds, mutual funds, insurance companies, and sovereign wealth funds, can be a prime potential source of capital for renewable energy. One way to ensure increased investment commitment from such investors is for them to treat clean energy as a separate asset class in their portfolios. Through this paper, our aim is to present initial insights into the potential effect the addition of clean energy listed equity as a separate asset class can have on existing portfolios. We focus on the value of listed renewable energy equity in a static portfolio optimization problem. Our main finding is that treating renewable energy listed equity as a separate asset class within an investor's portfolio does not appear to add value to that portfolio. On one hand, this may reflect the need for applying more sophisticated techniques to show value. On the other hand, it may also imply that governments, policy makers, and regulators must keep working to ensure the clean energy sector is conducive to mainstream investment.
Detecting Journalism in the Age of Social Media:Three Experiments in Classifying Journalists on Twitter

The widespread adoption of networked information and communications technologies (i.e. ICTs) blurs traditional boundaries between journalist and citizen. The role of the journalist is adapting to structural changes in the news industry and dynamic audience expectations. For researchers who seek to understand what, if any, distinct role journalists play in the production and propagation of breaking news, it is vital to be able to identify journalists in social media spaces. In many cases, this can be challenging due to the limited information and metadata about social media users. In this work, we use a supervised machine learning model to automatically distinguish journalists from non-journalists in social media spaces. Leveraging Twitter data collected from three crisis events of different types, we examine how profile information, social network structure, posting behavior and language distinguish journalists from others. Additionally, we evaluate how the performance of the journalist classification model varies by context (i.e. types of crisis events) and by journalism outlets (i.e. print versus broadcast journalism), and discuss challenges in automatic journalist detection. Implications of this work are discussed; in particular we argue for the value of such methods for scaling analysis in journalism studies beyond the capacity of human coders. Employing classification methods in this context allows for systematic, large-scale studies of the role of journalists online.
Efficacy of Novel Antimicrobial Post-milking Teat Dip on the Rate of New Intramammary Infections with an Experimental Bacterial Challenge against Contagious Mastitis Organisms

Teat dipping with effective products is a critical control point for mastitis prevention. Objective of this study was to determine efficacy of a novel antimicrobial solution containing citrate ion, methylene blue, parabens and emollients (ZuraLacSD, Zurex PharmAgra) used as a post-milking teat dip against a positive control and negative control in reducing the incidence of new intramammary infections during a period of experimental exposure of teats to contagious mastitis organisms, Streptococcus agalactiae and Staphylococcus aureus. Novel germicide post milking teat dip significantly (P < 0.01%) reduced the number of new infections of Streptococcus agalactiae and Staphylococcus aureus compared to both the negative control (95.3%) and positive control (80.9%) treatments. Incidence of clinical mastitis with a bacteriological positive identification of one of the challenge organisms was 40, 4 and 0 for negative control, positive control and novel germicide dips, respectively. Under the conditions of this study, no differences were visually observed for teat skin condition among the treatments. The use of a novel germicide used in a post-milking teat dip significantly reduced the number of new intramammary infections (new IMI) caused by experimental challenge with contagious mastitis pathogens Strep. agalactiae and Staphylocccus aureus compared to no post-milking teat dipping (negative control) and to an industry standard, 0.5% iodine post-milking teat dip.
I Think I Can Trust Alexa, But How Much?

As our society becomes increasingly data-driven, it becomes more imperative that we strive to keep our data safe and in hands we trust. Software and businesses collect and utilize vast amounts of data to operate. Most people find it difficult to function in today’s society without smartphones, given the ubiquity of social media. Social media is an example of a technology for which people have generally accepted that some of their data may be visible to the developers, and possibly the public, due to enough confidence in its security; lack of foresight to be concerned; or perhaps obliviousness to the consequences of a data breach. I consider newer technologies such as artificial intelligence personal assistants, which can behave most effectively by learning first about humans, or more specifically, the individual(s) each one serves; in other words, they require user data to perform well. Like social media, while usage of these products incurs risks, people still use them, which introduces a problem where the users of a product are in a position to be taken advantage of by attackers or the product's company. In my STS thesis, I aim to understand what factors are causing people to adopt artifical intelligence (AI) personal assistants and Internet of Things (IoT) devices despite the risks, as well as what actions different actors are taking or should be taking.
Role of Hyperinsulinemia and Insulin Resistance in Hypertension: Metabolic Syndrome Revisited

Hyperinsulinemia and insulin resistance were proposed more than 30 years ago to be important contributors to elevated blood pressure (BP) associated with obesity and the metabolic syndrome, also called syndrome X. Support for this concept initially came from clinical and population studies showing correlations among hyperinsulinemia, insulin resistance, and elevated BP in individuals with metabolic syndrome. Short-term studies in experimental animals and in humans provided additional evidence that hyperinsulinemia may evoke increases in sympathetic nervous system (SNS) activity and renal sodium retention that, if sustained, could increase BP. Although insulin infusions may increase SNS activity and modestly raise BP in rodents, chronic insulin administration does not significantly increase BP in lean or obese insulin-resistant rabbits, dogs, horses, or humans. Multiple studies in humans and experimental animals have also shown that severe insulin resistance and hyperinsulinemia may occur in the absence of elevated BP. These observations question whether insulin resistance and hyperinsulinemia are major factors linking obesity/metabolic syndrome with hypertension. Other mechanisms, such as physical compression of the kidneys, activation of the renin-angiotensin-aldosterone system, hyperleptinemia, stimulation of the brain melanocortin system, and SNS activation, appear to play a more critical role in initiating hypertension in obese subjects with metabolic syndrome. However, the metabolic effects of insulin resistance, including hyperglycemia and dyslipidemia, appear to interact synergistically with increased BP to cause vascular and kidney injury that can exacerbate the hypertension and associated injury to the kidneys and cardiovascular system.
Linking Features of Genomic Function to Fundamental Features of Learned Vocal Communication

Learned vocal communication emerges from the coordination of sensory and motor learning, reflects the function of a distributed but integrated neural circuit, and unfolds across several timescales, often occurring in maturing animals. Because nearly all brain organization and function originates from patterns of genomic activation, it is crucial to understand principles of how the genome works in order to understand how learned vocal communication arises. In this chapter, the fact that genome functions have high evolutionary conservation will be leveraged to provide a conceptual guide for how research using a species of songbird, the zebra finch, can deepen and expand clinical findings from humans. Additionally, this chapter provides examples for how studies in the zebra finch can uncover fundamental processes of learned vocal communication that are of value for understanding human speech and language. Examples include the organization of specialized neural circuits, responses to social communication experiences, activation of motor plans, and consideration of how the age and sex of the individual intersect with vocal communication skills, all of which have potential to inform on vocal learning mechanisms in humans. Together, our current state of knowledge advances the idea that humans and songbirds do not simply share superficial parallels; rather, they share deep biological properties to accomplish the complex, multi-level processes required for learning and producing meaningful communication patterns.
Presentazione dei 6 numeri di Libya antiqua (2011-18), Rivista annuale del Dipartimento delle antichità della Libia (Annual of the Department of Antiquities of Libya)

Presentation of the 6 issues of Libya antiqua (2011-18),Annual magazine of the Department of Antiquities of Libya(Annual of the Department of Antiquities of Libya)Macerata, 26 November 2019
Physical Activity in Early- and Mid-Adulthood Are Independently Associated With Longitudinal Memory Trajectories in Later Life.

Background Physical activity (PA) in later-life may reduce dementia risk, but little is known regarding long-term cognitive effects of PA that occurred earlier in adulthood or mechanisms underlying associations. PA patterns at different ages may independently contribute to dementia risk, which would implicate multiple critical periods for intervention. The current study tested whether retrospective reports of PA in early- and mid-adulthood were independently associated with later-life longitudinal memory outcomes and whether associations were mediated by late-life cardiometabolic diseases. Methods Participants comprised 5,200 Health and Retirement Study Life History Mail Survey respondents. Latent growth curves estimated independent associations between retrospectively reported PA in early-adulthood (age 18-29) and mid-adulthood (age 40-49) and 16-year episodic memory trajectories. Indirect pathways involving the maintenance of PA from early- to mid-adulthood and the influence of PA on later-life cardiometabolic diseases (hypertension, diabetes, and heart disease) were also estimated. Results PA in early- and mid-adulthood independently predicted higher initial memory level and slower memory decline in later-life, respectively. Early-adulthood PA was indirectly associated with later-life memory level through higher mid-adulthood PA and lower rates of later-life hypertension, as well as with subsequent memory decline through higher mid-adulthood PA. Conclusions The current findings highlight the importance of PA throughout adulthood, such that initiating and/or maintaining exercise in early- or mid-adulthood may be protective for later-life cognitive health, and hypertension appears to represent a key mediator of these effects.
A SEARCH FOR LYMAN BREAK GALAXIES IN THE CHANDRA DEEP FIELD SOUTH USING SWIFT ULTRAVIOLET/OPTICAL TELESCOPE

While the Swift satellite is primarily designed to study gamma-ray bursts, its ultraviolet and optical imaging and spectroscopy capabilities are also being used for a variety of scientific programs. In this study, we use the UV/Optical Telescope (UVOT) instrument on board Swift to discover 0.5 60 ks exposure time, achieving a limiting magnitude of u < 24.5, in the Chandra Deep Field South (CDF-S). Applying UVOT near-ultraviolet color selection, we select 50 UV-dropouts from this UVOT CDF-S data. We match the selected sources with available multiwavelength data from Great Observatories Origins Deep Survey (GOODS) South, Multiwavelength Survey by Yale-Chile, and COMBO-17 to characterize the spectral energy distributions for these galaxies and determine stellar masses, star formation rates (SFRs), and dust attenuations. We compare these properties for LBGs selected in this paper versus z {approx} 3 LBGs and other CDF-S galaxies in the same redshift range (0.5 < z < 2), identified using photometric redshift techniques. The z {approx} 1 LBGs have stellar masses of (logM{sub *}/M{sub sun}) = 9.4 {+-} 0.6, which is slightly lower than z {approx} 3 LBGs ((logM{sub *}/Ms{sub un}) = 10.2more » {+-} 0.4) and slightly higher compared with the z {approx} 1 CDF-S galaxies ((logM{sub *}/M{sub sun}) = 8.7 {+-} 0.7). Similarly, our sample of z {approx} 1 LBGs has SFRs (derived using both ultraviolet and infrared data, where available) of (logSFR/(M{sub sun} yr{sup -1})) = 0.7 {+-} 0.6, nearly an order of magnitude lower than z {approx} 3 LBGs ((logSFR/M{sub sun} yr{sup -1}) = 1.5 {+-} 0.4), but slightly higher than the comparison z {approx} 1 sample of CDF-S galaxies ((logSFR/M{sub sun} yr{sup -1}) = 0.2 {+-} 0.7). We find that our z {approx} 1 UV-dropouts have (A{sub FUV}) = 2.0 {+-} 1.0, which is higher than z {approx} 3 LBGs ((A{sub FUV}) = 1.0 {+-} 0.5), but similar to the distribution of dust attenuations in the other CDF-S galaxies ((A{sub FUV}) {approx} 2.8 {+-} 1.5). Using the GOODS-South multiwavelength catalog of galaxies, we simulate a larger and fainter sample of LBGs to compare their properties with those of the UVOT-selected LBG sample. We conclude that UVOT can be useful for finding and studying the bright end of 0.5 < z < 2.0 LBGs.« less
Engaging Patients to Ask More Questions: What's the Best Way? A Pragmatic Randomized Controlled Trial.

Purpose Hand conditions are common, and often require a discussion of the tradeoffs of different treatment options. Our goal was to evaluate whether providing patients with a Question Prompt List (QPL) for common hand conditions improves their perceived involvement in care compared with providing patients with 3 generic questions. Methods We performed a prospective, single-center, pragmatic randomized controlled trial. We created a QPL pamphlet for patients with common hand conditions. New patients with common hand conditions were enrolled between April 2019 and July 2019 and were randomized into either the QPL group (with 35 hand-specific questions) or the AskShareKnow group (3 generic questions: [1] What are my options? [2] What are the possible benefits and harms of those options? [3] How likely are each of these benefit and harms to happen to me?). Both groups received the questions prior to meeting with their surgeon. We used the Perceived Involvement in Care Scale (PICS), a validated instrument designed to evaluate patient participation in decision-making, as our primary outcome. The maximum PICS score is 13, and a higher score indicates higher perceived involvement. Results One hundred twenty-six patients participated in the study, with 63 patients in the QPL group and 63 patients in the AskShareKnow group. The demographic characteristics were similar in the 2 groups. The mean AskShareKnow group PICS score was 8.3 ± 2.2 and the mean QPL PICS score was 7.5 ± 2.8, which was not deemed clinically significant. Conclusions The QPLs do not increase perceived involvement in care in patients with hand conditions compared with providing patients with 3 generic questions. Clinical relevance Various approaches have been evaluated to help improve patient involvement in their care. In hand surgery, 3 generic questions were no different than a lengthy QPL with respect to patient involvement in their care.
Fighting Poverty, Combatting Social Exclusion

The Chinese have a saying: through a drop of water you can see the whole ocean. This chapter analyzes the process of integrating social development policy and practice into the operations of the World Bank through the lens of my own personal experience, a drop of water through which we will see how sociologists and anthropologists transformed the larger organizational culture of the institution.
“But That’s Not My Job”: Employee Resistance to Extra-Role Tasks

Supervisors sometimes assign employees extra-role tasks, which are often perceived as unreasonable and can prompt employee resistance. In an experiment, we investigated employees’ likelihood of dec...
Physical and Chemical Studies on Ceruloplasmin IV. PREPARATION OF RADIOACTIVE, SIALIC ACID-FREE CERULOPLASMIN LABELED WITH TRITIUM ON TERMINAL D-GALACTOSE RESIDUES

Abstract Crystalline ceruloplasmin was substantially freed of sialic acid by the action of neuraminidase. Sequential treatment of asialoceruloplasmin with galactose oxidase and tritiated borohydride resulted in the incorporation of tritium into at least 4 residues of D-galactose of the protein molecule.
Effect of radiofrequency catheter ablation of ventricular tachycardia on left ventricular function in patients with prior myocardial infarction.

Introduction: Successful RF ablation of VT late after MI can involve multiple applications and long lines of RF lesions. The impact on left ventricular function is potentially important, but not well defined. Quantitative echocardiography was used to determine the effect of radiofrequency (RF) ablation on left ventricular function in patients with ventricular tachycardia (VT) after myocardial infarction (MI).
Growth and redistribution components of changes in poverty measures : a decomposition with applications to Brazil and India in the 1980s

This report shows how changes in poverty. measures can be decomposed into growth and redistribution components, and uses the methodology to study poverty in Brazil and India during the 1980s. Redistribution alleviated poverty in India, through growth was quantitatively more important. Improved distribution countervailed the adverse effect of monsoon failure in the late 1980s on rural poverty. However, worsening distribution in Brazil, associated with the macroeconomic shocks of the 1980s, mitigated poverty alleviation through the limited growth that occurred. India's higher poverty level than Brazil is accountable to India's lower mean consumption; Brazil's worse distribution mitigates the cross-country difference in poverty.
Kinetic analysis of the reaction of cytochrome cc' with carbon monoxide.

Abstract The equilibria and kinetics of the reaction of the diheme proteins cytochrome cc' derived from Rhodospirillum rubrum and Chromatium with carbon monoxide have been examined. There are wide differences in many respects. The pigment from Chromatium is half saturated by 0.2 µm CO, while that of R. rubrum requires a concentration of 400 µm. The kinetics of the combination reaction also differs. In stopped flow experiments, the rate for R. rubrum cytochrome cc' is independent of CO concentration over the range examined, while that for the Chromatium pigment is proportional to CO concentration and yielded a second order rate constant of 260 m-1 sec-1 at room temperature. Flash photochemical experiments gave biphasic recombination reactions, with rates independent of carbon monoxide concentration in both cases. The reactions are much faster than those observed by the stopped flow method. The velocity of dissociation of CO was measured for the pigment from R. rubrum by dilution and was 0.009 sec-1, at 22° and pH 7.4. The equilibrium between CO and both proteins could be displaced by steady illumination from medium intensity sources such as tungsten filaments. In the Chromatium pigment, the rates of photodissociation and recombination were independent of light intensity. They varied with CO concentration and were numerically equal at CO concentrations greater than 1 x 10-4 m. In R. rubrum cytochrome cc' the photochemical behavior was analogous to that of myoglobin in that there was the usual dependence of rate of dissociation on light intensity. Preliminary experiments on the reaction of the reduced hemoproteins with oxygen and on the reaction of the carbon monoxide complexes with oxygen have given complicated results which cannot be summarized briefly. The findings may be explained by the hypothesis that a bound carbon monoxide molecule, after dissociation from the heme as judged spectrophotometrically, retains an association with the protein molecule. The conclusions resulting from this scheme are discussed in detail.
Imaging of Embedded Clusters: Mon R2

Isolated clusters of young stars embedded within molecular clouds provide unique opportunities to study star formation. They are ideal for establishing the timescales for star formation as well as determining the emergent mass spectrum of stellar groups. Such embedded clusters, bound by parent molecular gas, preserve a record of the mass distribution in a localized region of space. We present results from our near-IR survey of the Mon R2 molecular core studied by Xie (1992). Through analysis of color-color and color-magnitude diagrams based on JHK imaging photometry, we determine the fraction of young stars surrounded by accretion disks, and investigate the age and mass distribution of the cluster.
Mice lacking serum paraoxonase are susceptible to organophosphate toxicity and atherosclerosis

Serum paraoxonase (PON1) is an esterase that is associated with high-density lipoproteins (HDLs) in the plasma; it is involved in the detoxification of organophosphate insecticides such as parathion and chlorpyrifos. PON1 may also confer protection against coronary artery disease by destroying pro-inflammatory oxidized lipids present in oxidized low-density lipoproteins (LDLs). To study the role of PON1 in vivo, we created PON1-knockout mice by gene targeting. Compared with their wild-type littermates, PON1-deficient mice were extremely sensitive to the toxic effects of chlorpyrifos oxon, the activated form of chlorpyrifos, and were more sensitive to chlorpyrifos itself. HDLs isolated from PON1-deficient mice were unable to prevent LDL oxidation in a co-cultured cell model of the artery wall, and both HDLs and LDLs isolated from PON1-knockout mice were more susceptible to oxidation by co-cultured cells than the lipoproteins from wild-type littermates. When fed on a high-fat, high-cholesterol diet, PON1-null mice were more susceptible to atherosclerosis than their wild-type littermates.
Hydroacoustic investigation of submarine landslides at West Mata volcano, Lau Basin

Submarine landslides are an important process in volcano growth yet are rarely observed and poorly understood. We show that landslides occur frequently in association with the eruption of West Mata volcano in the NE Lau Basin. These events are identifiable in hydroacoustic data recorded between ~5 and 20 km from the volcano and may be recognized in spectrograms by the weak and strong powers at specific frequencies generated by multipathing of sound waves. The summation of direct and surface-reflected arrivals causes interference patterns in the spectrum that change with time as the landslide propagates. Observed frequencies are consistent with propagation down the volcano's north flank in an area known to have experienced mass wasting in the past. These data allow us to estimate the distance traveled by West Mata landslides and show that they travel at average speeds of ~10–25 m/s.
Requirements management at NASA

Summary form only given, as follows. Requirements have always been acknowledged as the backbone of any system. However, in many past development efforts, requirements were paid little heed. At NASA, in recent years, the hue and cry for project development has been "Faster, Better, Cheaper and Safer." This has impacted the way we develop software; it has increased the risks to quality, safety and reliability. At NASA, the Software Assurance Technology Center (SATC) is working with projects to emphasize the criticality of requirements throughout development, not just in the initial phases. This emphasis is on requirements relationship to all aspects of quality, including reliability and safety. In this presentation, we will look at some of these relationships through the eyes of quality.
The Invisibility of Racial Minorities in the Public Realm of Appearances

During the strike that preceded the assassination of Martin Luther King Jr., the sanitation workers of Memphis and their African-American supporters paraded with posters that read, “I AM A MAN.” This was not only a labor dispute in which the right of public employees to strike against a city was in question, but it was also, given the historical context and especially the racial identity of most of the sanitation workers, immediately recognized as an important chapter in the Civil Rights Movement. There were signs that read “JOBS JOBS JOBS,” “UNIONIZATION FOR THE SANITATION WORKERS,” and “JUSTICE AND EQUALITY FOR ALL MEN.” But most signs read simply “I AM A MAN,” and the photographs of scores of Black protesters holding these signs provide the abiding image of the strike. They wanted economic justice and recognition of their union, but contemporary accounts record that more than anything else they wanted to be “recognized” for themselves.1
Hydrogen export from intertidal cyanobacterial mats: sources, fluxes and the influence of community composition

Summary Microbial mats from marine intertidal settings have been reported to release significant quantities of H2, in a unique trait among other mats and microbial communities. However, the H2 source and ecophysiological mechanisms that enable its export are not well understood. We examined H2 accumulation and export in three types of greenhouse-reared mats, from the intertidal region of Guerrero Negro, Mexico, and kept under natural light–dark conditions and wetting and drying cycles simulating low-, mid- and high-tidal height periodicity. All mats released H2 reproducibly and sustainably for 1.5 years. Net H2 export took place in a pulsed daily manner, starting after dusk, and waning in the morning, as photosynthesis resumed. Mid- and low-tidal mats developed high concentrations, capable of sustaining export fluxes that represented 2–4% of the water split through primary productivity. Neither N2 fixation nor direct photolytic hydrogenogenesis was significant to this H2 export, which was fermentative in origin, variable among mats, originating from cyanobacterial photosynthate. Analyses of community composition by pyrosequencing of 16S rRNA and hoxH genes indicate that filamentous non-heterocystous cyanobacteria (e.g. Lyngbya, Microcoleus) were important in the process of H2 export, as was the relatively low abundance and activity of methanogens and sulfate reducers.
Fuel-Efficient Descent and Landing Guidance Logic for a Safe Lunar Touchdown

The landing of a crewed lunar lander on the surface of the Moon will be the climax of any Moon mission. At touchdown, the landing mechanism must absorb the load imparted on the lander due to the vertical component of the lander’s touchdown velocity. A large horizontal velocity must also be avoided because it could cause the lander to tip over, risking the life of the crew. To be conservative, the worst-case lander’s touchdown velocity is always assumed in designing the landing mechanism, making it very heavy. Fuel-optimal guidance algorithms for soft planetary landing have been studied extensively. In most of these studies, the lander is constrained to touchdown with zero velocity. With bounds imposed on the magnitude of the engine thrust, these optimal control solutions typically have a “bang-bang” thrust profile: the thrust magnitude “bangs” instantaneously between its maximum and minimum magnitudes. But the descent engine might not be able to throttle between its extremes instantaneously. There is also a concern about the acceptability of “bang-bang” control to the crew. In our study, the optimal control of a lander is formulated with a cost function that penalizes both the touchdown velocity and the fuel cost of the descent engine. In this formulation, there is not a requirement to achieve a zero touchdown velocity. Only a touchdown velocity that is consistent with the capability of the landing gear design is required. Also, since the nominal throttle level for the terminal descent sub-phase is well below the peak engine thrust, no bound on the engine thrust is used in our formulated problem. Instead of bang-bang type solution, the optimal thrust generated is a continuous function of time. With this formulation, we can easily derive analytical expressions for the optimal thrust vector, touchdown velocity components, and other system variables. These expressions provide insights into the “physics” of the optimal landing and terminal descent maneuver. These insights could help engineers to achieve a better “balance” between the conflicting needs of achieving a safe touchdown velocity, a low-weight landing mechanism, low engine fuel cost, and other design goals. In comparing the computed optimal control results with the preflight landing trajectory design of the Apollo-11 mission, we noted interesting similarities between their landing performance.
The effectiveness in rhesus monkeys of an antifertility vaccine based on neutralization of chorionic gonadotropin.

Abstract A model system, employing non-human primates, is needed to test the postulate that active immunization to achieve neutralization of the biological activity of chorionic gonadotropin could be used as a basis for fertility regulation in women. Adult female rhesus monkeys were actively immunized with the β-subunit of ovine LH (oLHβ) mixed with Freund's complete adjuvant. All monkeys developed circulating antibodies which bound iodinated oLH and human chorionic gonadotropin (hCG). The bound hCG was displaced by rhesus chorionic gonadotropin (rhCG). Antisera were also able to neutralize the biological activity of rhCG in the immature rat uterine weight assay. Serum progesterone levels and menstrual bleeding patterns indicated that normal ovulatory cycles continued to occur in most cases after immunization. Results of mating the animals reveal that the fertility of the immunized animals was significantly reduced.
X-Linked gene activity in metamales (XY; 3A) of Drosophila

In order to determine the level of X-linked gene activity in metamales (XY; 3A) of Drosophila melanogaster, RNA synthesis was monitored as a function of 3H-uridine incorporation in nuclei of isolated larval salivary glands by standard autoradiographic means. These data show that the rate of RNA synthesis by the single X chromosome in metamales is approximately 90% of the rate achieved by the three X chromosomes of triploid females (3X; 3A). As an independent measure of chromosome activity, two X-linked enzymes and two autosomal enzymes were monitored in crude extracts by spectrophotometric assay procedures. The results reveal that X-linked enzyme activity levels in metamales constitute 80% of the levels exhibited by control triploid females or intersexes (XXY; 3A). We conclude that metamales exhibit substantial compensation beyond that which occurs in regular, diploid males. This finding establishes a new level of transcriptional activity possible for the X chromosome of Drosophila melanogaster.
Kinetic asymmetry in female runners with and without retrospective tibial stress fractures

Gait asymmetry may be linked to the tendency for runners to sustain chronic overuse injuries. This paper compares gait asymmetry in female runners who have never sustained a running-related injury to those who have sustained unilateral tibial stress fractures. The symmetry index was used to characterize asymmetry in the kinetics of both subject groups. There were three aims to this study: (1) to report natural levels of asymmetry for healthy, never-injured female runners, (2) to compare asymmetry levels between never-injured runners and those who have sustained stress fractures, and (3) to examine the kinetics between the involved and uninvolved limbs of runners who have sustained stress fractures. In all three aims, peak medial, lateral, braking, vertical impact, and vertical ground reaction forces, average and peak instantaneous vertical loading rates, and peak shock were examined. In the never-injured runner group, natural levels of asymmetry ranged from 3.1% for peak vertical ground reaction force up to 49.8% for peak lateral ground reaction force. Symmetry indices were not significantly different in the runners who had previously sustained stress fractures. The involved limb of the previously injured runners demonstrated higher values for braking and vertical impact ground reaction force and peak shock. Interestingly, these runners appeared to have bilaterally-elevated lateral ground reaction forces and loading rates as compared to the never-injured group, although this was not statistically tested. This suggests that previously injured runners may be closer to the injury threshold and, thus, more susceptible. Asymmetry may simply influence the side on which they become injured.
Transverse vertex and gauge technique in quantum electrodynamics

It is known that the Schwinger-Dyson equation for the electron propagator $S(p)$ in quantum electrodynamics is linear if the full vertex in this equation is approximated by a special form (the longitudinal vertex) which satisfies the Ward identity and which yields exact results in the infrared regime. However, the approximate equation cannot be multiplicatively renormalized (nor is it properly gauge covariant) using only the longitudinal vertex. In the present work, we construct a transverse (i.e., identically conserved) vertex which, when added to the longitudinal vertex, yields an equation for $S(p)$ which remains linear and exact in the infrared, but which is multiplicatively renormalizable and gauge covariant. In the ultraviolet regime, the equation gives the known results of renormalization-group-improved perturbation theory. The essential difficulty which is overcome by the present analysis is that of overlapping divergences, which are mishandled if only the longitudinal vertex is kept.
Noise-induced bistability in a Monte Carlo surface-reaction model

We find a noise-induced transition to bistability in a Monte Carlo simulation of a model heterogeneous catalytic chemical reaction which is deterministically monostable. Analysis of the probability density function and the correlation integral of time series of this model indicates the existence and central role of noise in this transition. We find that the behavior of this system is a consequence of the interaction of noise with the spatial degrees of freedom on the model catalytic surface.