cssi/SciSciGPT-SciSciNet huggingface dataset:
Leveraging Cellular Intemet-of-Things for Resilient and Robust Disaster Management

To improve operational efficiency, disaster management missions increasingly employ smart and interconnected devices. Autonomous robots are used for remote access, drones for impact zone surveys, and wireless sensors for human presence detection. The interconnection between these devices was mainly realized using wireless protocols for local and ad-hoc access to allow quick information exchange with the first responders. For large scale disasters, however, there is a need for a wide area wireless access, resilient to communication outages to provide robust operational efficiency by interconnecting large number of smart devices. To address this need, the article discusses how the recent advancements in Cellular IoT can be leveraged in a large-scale and complex disaster management missions. The CIoT technologies are also considered in the context of minimizing the time to restore normalcy in cooperation with the existing disaster management solutions.
Population-based genome-wide association study of cognitive decline in older adults free of dementia: identification of a novel locus for the attention domain.

Abstract To identify novel loci that affect cognitive decline in older adults free of dementia, we conducted genome-wide and gene-based meta-analyses on longitudinal slopes of 5 cognitive domains (memory, executive function, language, attention/processing speed, and visuospatial ability) derived from 2 population-based cohorts. For decline over time in each cognitive domain, we normalized intraindividual slopes within each cohort, accounting for baseline age, sex, and years of education. Normalized slope for each domain was used in cohort-specific genome-wide analyses after including top principal components as covariates followed by genome-wide and gene-based meta-analyses. Both analyses revealed a novel WDFY2 locus at genome-wide (p = 3.37E-08) and gene-wide (p = 7.10E-07) significance levels for the attention/processing speed domain. In the GTEx eQTL analysis, genome-wide significant single-nucleotide polymorphism was associated with RNA expression levels of WDFY2 in several brain regions: cerebellar hemisphere (p = 1.07E-04), cerebellum (p = 6.92E-04), hippocampus (p = 2.18E-03) and cortex (p = 2.29E-02), and in whole blood (p = 4.41E-05). Our results suggest that WDFY2 genetic variation may affect individual differences in decline over time on tests of attention/processing speed.
Nonlinear generation of sum frequencies in Sitka spruce

It has been known for several decades that there are anomalous frequency components in the sound of a piano. These occur at the sum and difference frequencies of the overtones attributable to string motion, and are commonly referred to as phantom partials. Recent work has shown that, contrary to the generally accepted theory, the majority of power in these frequency components originates in the wooden parts of the piano and not the string. However, the etiology of the nonlinearity is not clear. To determine if the source of the nonlinearity is the stress caused by the pressure of the strings on the soundboard, experiments were performed on isolated pieces of Sitka spruce. The results indicate that stress can significantly increase the nonlinear response of the wood. [Work supported by NSF Grant #PHY-160749.]It has been known for several decades that there are anomalous frequency components in the sound of a piano. These occur at the sum and difference frequencies of the overtones attributable to string motion, and are commonly referred to as phantom partials. Recent work has shown that, contrary to the generally accepted theory, the majority of power in these frequency components originates in the wooden parts of the piano and not the string. However, the etiology of the nonlinearity is not clear. To determine if the source of the nonlinearity is the stress caused by the pressure of the strings on the soundboard, experiments were performed on isolated pieces of Sitka spruce. The results indicate that stress can significantly increase the nonlinear response of the wood. [Work supported by NSF Grant #PHY-160749.]
Asparaginase combined with discontinuous dexamethasone improves antileukemic efficacy without increasing osteonecrosis in preclinical models.

Introduction Combination therapy for acute lymphoblastic leukemia (ALL) is highly effective but results in significant toxicity including osteonecrosis. Asparaginase is known to potentiate both the antileukemic and osteonecrosis-inducing effects of dexamethasone. The schedule of dexamethasone alters osteonecrosis risk. However, the effects of the interaction with asparaginase are unknown when dexamethasone is given on a discontinuous schedule. Methods Using the murine model of osteonecrosis, we compared the frequency of osteonecrosis in mice receiving discontinuous dexamethasone (3.5 days/ week) with mice receiving asparaginase and discontinuous dexamethasone. We then tested the effect on antileukemic efficacy using six pediatric ALL xenografts. Results The addition of asparaginase to discontinuous dexamethasone did not alter the rate of osteonecrosis compared to dexamethasone alone (7/35 in dexamethasone with asparaginase combination vs. 10/36 in dexamethasone alone, p = 0.62) despite increasing steady-state plasma dexamethasone levels (103.9 nM vs. 33.4 nM, p = 9.2x10-7). Combination therapy with asparaginase and dexamethasone demonstrated synergistic antileukemic effects across all six xenografts studied. Conclusions When discontinuous dexamethasone was given, its anti-leukemic activity synergized with asparaginase but the osteonecrosis-worsening effects of asparaginase (above dexamethasone alone) were not observed. Thus, there is a favorable drug interaction (unchanged toxicity, synergistic efficacy) between discontinuous dexamethasone and asparaginase.
Fine Tuning, Sequestering, and the Swampland

Abstract We conjecture and present evidence that any effective field theory coupled to gravity in flat space admits at most a finite number of fine tunings, depending on the amount of supersymmetry and spacetime dimension. In particular, this means that there are infinitely many non-trivial correlations between the allowed deformations of a given effective field theory in the gravitational context. Fine tuning of parameters allows us to obtain some consistent CFTs in the IR limit of gravitational theories. Related to finiteness of fine tunings, we conjecture that except for a finite number of CFTs, the rest cannot be consistently coupled to gravity and belong to the swampland. Moreover, we argue that even though matter sectors coupled to gravity may sometimes be partially sequestered, there is an irreducible level of mixing between them, correlating and coupling infinitely many operators between these sectors.
Recent Progress in Unusual Carbohydrate-Containing Natural Products Biosynthesis

Abstract Carbohydrates are present in all living organisms. They have long been recognized to play essential roles in metabolism and mediate a great variety of other physiological processes. A unique characteristic of carbohydrates is their structural diversity. Unusual sugars are frequently found in the secondary metabolites of microorganisms and plants. These sugar residues are crucial in conferring optimal biological activity of many natural products and their removal often leads to loss of all biological activity of the parent compounds. Since gaining knowledge of the biosynthesis of these unusual sugars is essential for the development of methods to control or inhibit their production, study of the biosynthesis of unusual carbohydrates has been the focus of intense research in recent years. Significant progress has been made in this field due to the advancements in sequencing technology that have expedited the identification of gene clusters responsible for the biosynthesis of sugar-containing natural products. This review presents a survey of the biosynthesis of unusual carbohydrates investigated within the past decade with a particular emphasis on nucleoside analogs, high-carbon sugars and carbohydrates with nitrogen- and sulfur-containing functional groups.
Light tunable plasmonic metasurfaces

Self-assembled plasmonic metasurfaces are promising optical platforms to achieve accessible flat optics, due to their strong light-matter interaction, nanometer length scale precision, large area, light weight, and high-throughput fabrication. Here, using photothermal continuous wave laser lithography, we show the spectral and spatial tuning of metasurfaces comprised of a monolayer of ligand capped hexagonally packed gold nanospheres. To tune the spectral response of the metasurfaces, we show that by controlling the intensity of a laser focused onto the metasurface that the absorption peak can be reconfigured from the visible to near-infrared wavelength. The irreversible spectral tuning mechanism is attributed to photothermal modification of the surface morphology. Combining self-assembled metasurfaces with laser lithography, we demonstrate an optically thin (λ/42), spectrally selective plasmonic Fresnel zone plate. This work establishes a new pathway for creating flat, large area, frequency selective optical elements using self-assembled plasmonic metasurfaces and laser lithography.
Management and outcomes of uncomplicated ST-segment elevation myocardial infarction patients transferred after fibrinolytic therapy.

Abstract Background This study sought to assess the contemporary outcomes of patients transferred after receiving fibrinolytic therapy (‘drip-and-ship’) for ST-segment elevation myocardial infarction (STEMI) in the United States. Methods During 2009–2016, adults (>18 years) with STEMI (>18 years) without cardiac arrest and cardiogenic shock that received fibrinolytic therapy and were subsequently transferred were identified using the National Inpatient Sample (NIS). These admissions were divided into those undergoing fibrinolysis alone, subsequent coronary angiography (CA) without revascularization and subsequent CA with revascularization. Outcomes of interest included in-hospital mortality, resource utilization, and discharge disposition. Results A total of 27,454 STEMI admissions receiving a ‘drip-and-ship strategy’, 96.3% and 85.8% received subsequent coronary angiography and revascularization Admissions receiving CA and revascularization were younger, male, and with lower comorbidity. The fibrinolysis alone cohort had higher rates of organ failure, hemorrhagic sequelae, and intracranial hemorrhage. Compared to the fibrinolysis cohort, CA with revascularization (adjusted odds ratio [aOR] 0.17 [95% confidence interval {CI} 0.11–0.27]; p Conclusion Fibrinolysis with subsequent revascularization is associated with excellent outcomes in STEMI. Admissions receiving fibrinolysis alone were systematically different, sicker and had poorer outcomes.
Evaluating Accuracy of Numerical Simulations in Predicting Heating of Wire Implants During MRI at 1.5 T

Patients with long conductive implants such as deep brain stimulation (DBS) leads are often denied access to magnetic resonance imaging (MRI) exams due to safety concerns associated with radiofrequency (RF) heating of implants. Experimental temperature measurements in tissue-mimicking gel phantoms under MRI RF exposure conditions are common practices to predict in-vivo heating in the tissue surrounding wire implants. Such experiments are both expensive—as they require access to MRI units—and time-consuming due to complex implant setups. Recently, full-wave numerical simulations, which include realistic MRI RF coil models and human phantoms, are suggested as an alternative to experiments. There is however, little literature available on the accuracy of such numerical models against direct thermal measurements. This study aimed to evaluate the agreement between simulations and measurements of temperature rise at the tips of wire implants exposed to RF exposure at 64 MHz (1.5 T) for different implant trajectories typically encountered in patients with DBS leads. Heating was assessed in seven patient-derived lead configurations using both simulations and RF heating measurements during imaging of an anthropomorphic head phantom with implanted wires. We found substantial variation in RF heating as a function of lead trajectory; there was a 9.5-fold and 9-fold increase in temperature rise from ID1 to ID7 during simulations and experimental measurements, respectively. There was a strong correlation (r2 = 0.74) between simulated and measured temperatures for different lead trajectories. The maximum difference between simulated and measured temperature was 0.26 °C with simulations overestimating the temperature rise.
From colonial science to climate capacity building: Analyzing uneven access to climate knowledge in Vanuatu

Abstract This paper explores the uneven access to climate knowledge experienced by scientists and policymakers in Vanuatu. Rather than pointing to a lack of capability or forethought on the part of the Vanuatu government or scientists in Vanuatu, an examination of the colonial basis and economic investments necessary in climate science and monitoring elucidates how developing nations are systemically disadvantaged in climate research. Drawing from political ecology and science and technology studies these inequities are contextualized and spatially located through discourse analysis and qualitative interviews with ni-Vanuatu scientists, policymakers, and scholars. By situating climate science and climate knowledge in a historical perspective this paper provides a critique of the dominant view of climate research as neutral and necessarily global. This paper concludes by asserting climate knowledge inequities will not be resolved merely by more information, but only through addressing the root causes of these inequities over time.
Rethinking Margin and Volatility

This paper tests whether margin requirements cause asset price volatility. Using novel data on margin requirements and by exploiting exogenous variation from a threshold-based regression discontinuity design, I document that increasing margin causes a persistent decrease in future volatility (negative level effect) and a decline in trading volume. For an average 13.7% increase in margin requirement, I find an average 3.7% decrease in volatility. These results contrast with prior empirical studies that largely find no relationship between volatility and margin and provide support for the efficacy of financial market policies that seek to curb excess market volatility.
Fluctuations in Steady State Systems

In this paper, a summary of a multimode theory of fluctuations in steady state systems is presented. A detailed development of this theory is presented in a manuscript which will appear in Phys. Rev. A.
Evaluating impacts of CO2 intrusion into an unconsolidated aquifer: II. Modeling results

Large scale deployment of CO2 geological sequestration requires the assessment of the risks. One of the potential risks is the impact of CO2 leakage on shallow groundwater overlying the sequestration site.The understanding of the key chemical processes and parameters are critical for building numerical models for risk assessment. Model interpretation of laboratory and field tests is an effective way to enhance such understanding. As part of this investigation, column experiments in which the CO2 saturated synthetic groundwater flowed through a column packed with materials from the High Plains aquifer, were conducted. Changes in concentrations of several constituents in the column effluent and pH were determined. In this paper, a reactive transport model was developed to describe and interpret the observed concentration changes, attempting to shed light on the chemical reactions and mechanisms and key parameters that control the changes in effluent chemistry. The reactive transport model described fairly well the changes in pH and the concentration changes of Ca, Mg, Ba, Sr, Cs, As and Pb. Calcite dissolution and Ca-driven cation exchange reactions were the major drivers for the concentration changes of Ca, Ba, Sr, and Cs. The pH-driven adsorption/desorption reactions led to a concentration increase of As and Pb. The volume fraction and reactive surface area of calcite, CEC and sorption capacity were key parameters in controlling the magnitude of concentration increase. Model results also showed that Ba, which is an important chemical element released into the aqueous phase during these experiments, may be incorporated into the calcite crystal structure and the dissolution of Ba-bearing calcite could be an alternative pathway to explain the increase in aqueous Ba concentration when sediments are exposed to the CO2 saturated leaching groundwater.
Interaction with Nucleic Acids of Carcinogenic and Mutagenic N-Nitroso Compounds

Publisher Summary This chapter describes that in the case of mutagenesis, it is likely that alkylation of DNA at certain sites leads to mutations, and at most other sites to variable degrees of toxicity. The important sites of alkylation have not been established, but probably N-7 of guanine is not one of them; O6 of guanine or N-3 of adenine is more likely. It is also possible, because of some recent results, that interaction of the whole molecule, following activation, is an initial reaction of nitrosamines, and possibly even of nitrosamides. Intramolecular rearrangements during replication of the DNA might then lead to fixation of the lesion as a mutation. The relation of the reaction of nitroso compounds with nucleic acids to carcinogenesis is less decisive, and it cannot be said that any good correlations, withstanding rigorous tests, have been established. The existence of a deuterium isotope effect in carcinogenesis by nitrosamines implies that one of the initial steps in carcinogenesis is loss of a hydrogen atom alpha to the nitroso function. This is explainable in terms of formation of a simple alkylating agent from dimethylnitrosamine. However, other types of interaction of the latter with nucleic acids are certainly compatible with the lesser carcinogenicity of the deuterium-labeled compound. Such interactions could damage DNA, and differences in rates of repair that have been found are conceivable as responsible for the differential carcinogenic effects of various nitroso compounds. The chapter describes that correlations must be made with organ specificities and with differences in biological effect in different species. Minor differences in rate of some reaction must be related with sharp, all-ornothing differences in tumor response of one organ versus another.
The Legacy of Américo Paredes

Reviewed Medium: book Authors: Jose Lopez Morin Year: 2006 Pages: 194 Publisher: Texas AandM University Press ISBN: 978-1-58544-536-3 (soft cover). Prices: $19.95 USD(soft cover).
CRITIQUE - OF “FACTORS INFLUENCING NITRATE ACQUISITION BY PLANTS: ASSIMILATION AND FATE OF REDUCED NITROGEN”

Nitrate assimilation requires the function and regulation of three processes, namely (1) the uptake and translocation of nitrate from the environment into the cell, (2) the reduction of the anion to ammonium via nitrate and nitrite reductases, and (3) the incorporation of the reduced nitrogen into amino acid precursors. All three processes are anabolic and endothermic and, consequently, must be thermodynamically coupled to catabolic and exothermic reactions. While most of the recent research on nitrate assimilation has focused on one or the other of these processes individually, less attention has been given to describing the energy sources required for their function and the regulation of the processes by thermodynamic coupling.
Selected dimensions of service gender: a study of perceptions of Generation Y

Purpose – This paper aims to investigate how changes in technology and gender roles have changed Generation Y’s (Gen Y) perception of the gender of services from previous studies. Although the past 20 years have seen substantial changes in service delivery methods in addition to changes in the traditional roles of gender and households, in many ways, businesses continue to deliver products and services to their customers using traditional marketing techniques. Design/methodology/approach – Survey data were collected using a sample of 190 responses. Findings – Results indicate that consumers will consistently identify services as having gender, that consumers will rate service gender consistent with the perceived typical consumer of a service and that consumers will rate service gender consistent with the gender of their front-line employee. Online/automated services are also gendered. High-contact services have stronger gender identity than low-contact services. Congruence of consumer and service gender i...
Temporal patterns of reinforcer-induced general activity and attack in pigeons.

Abstract Three White King pigeons were exposed to fixed-time schedules ranging from 60 to 240 sec. General activity and attack against a conspecific target were measured separately at each interreinforcer interval value. Comparison of the temporal distributions of activity and attack revealed significant differences in their temporal locus and overall distribution between reinforcer presentations. At all interval values, attack was localized to the postreinforcer period, and peaked at the same absolute time (5–10 sec) following each reinforcer presentation. General activity was more uniformly distributed between reinforcers, and the peak level occurred later in the interval. As the interval length increased, peak levels of activity shifted to later times following reinforcement. These differences question traditional accounts which posit a unitary process underlying induced behaviors, while supporting Cohen, Looney, Campagnoni and Lawler's recent two-state model of induced behaviors [8].
Laser‐induced fluorescence of CsH (A 1Σ+→X 1Σ+) to levels near the dissociation limit of X 1Σ+

A new laser‐induced fluorescent doublet of CsH [A 1Σ+(v′ = 19)→X 1Σ+(v\ = vm)] is reported. The final vibrational‐rotational levels (v\ = vm, J\ = 9 or 11) are near the dissociation limit of the ground X 1Σ+ state. A comparison of the experimentally observed location and separation of the doublet with recent theoretical predictions is also presented.
Evaluation of Correlation Coefficients Obtained with a Stepwise Regression Analysis

The least-squares linear regression analysis is a valuable method of analyzing experimental data where there is no established theoretical relation between the variables being studied. The extent to which the variation of one variable can be predicted by another quantity that can be more readily measured is expressed by the correlation coefficient. The standard error of estimate indicates the precision of the prediction. In general, no single number will adequately indicate the quality of a relationship. This fact places a responsibility on the investigator to exercise sound judgment in evaluating the regression equation. Two methods of evaluation that are generally effective in identifying problems in the relationship are (1) to plot the results in a two-dimensional graph, and (2) to repeat the experiment. A nonlinear relationship was well as nonrandomness in the errors can be identified when the data are plotted. Repeated experiments can aid in the identification of variables that may influence the relationship, as well as inaccuracies, and can explain one's inability to extrapolate beyond the immediate data set.
The miniature pig as an animal model for the study of intestinal enzyme development.

ABSTRAm. Studies of intestinal enzyme development and regulation relevant to the human infant require an animal model with a rate of maturation similar to that of the human infant. Hanford miniature pigs were weaned at 3 days of age to a standard swine weaning formula. At 1, 2, 3, 4, 5, and 6 wk of age, duodenal jejunal, and ileal segments were analyzed for protein content and lactase, sucrase, maltase, glucoamylase, and acid P-galactosidase activities. Protein content of the small intestine changed significantly with age only in the ileum (p < 0.05). Lactase activity fell significantly with age in all segments of the small intestine (p < 0.001); activity was highest in the jejunum. Sucrase and maltase activities were present in all segments of the small intestine at 1 wk of age. Sucrase increased significantly (2-fold, p < 0.02) with age only in the ileum and maltase increased significantly with age in the jejunum (by 50%, p < 0.05) and the ileum (3-fold, p < 0.001). Activities were highest in the jejunum. Glucoamylase activity was present at 1 wk of age and showed a small but significant increase with age only in the duodenum (p < 0.005). Acid 8-galactosidase activity demonstrated small but significant decreases with age in all small intestinal segments. Glucoamylase and acid 0-galactosidase activities were similar in all segments. In the 6-wk-old pigs, activities of all the enzymes tested were similar to those found in young human infants. Our data demonstrate that the small intestinal enzyme development of the infant miniature pig is more advanced postnatally than other more commonly used animal species. The degree of small intestinal maturation and the similar intestinal enzyme distribution compared with that of the human infant suggest that the infant miniature pig is an excellent model for studies of intestinal enzyme development and regulation. (Pediatr Res 23: 311315,1988) Abbreviation PCMB, P-chloromercuribenzoate
Effect of reciprocal leniency on the relation between consideration scores from the Leader Behavior Description Questionnaire and performance ratings.

This study tested the hypothesis that “reciprocal leniency” moderated the relationship between Consideration scores on the Leader Behavior Description Questionnaire—Form XII and performance ratings. Reciprocal leniency was defined as a response style in which scores on the questionnaire are affected by harsh, lenient, or fair ratings made by the supervisor. Results partially supported the hypothesis.
Graves' disease: hyperthyroidism or hyperpituitarism.

THIS report presents the results of an effort to test two theories concerning the pathogenesis of hyperthyroidism. One is the possibility that the disorder is in effect a reflection of hyperpituitarism, the other that it is a derangement apart from the pituitary. The thyroid in health is thought to alter its level of activity in response to variations in thyrotropin release from the anterior pituitary. An increase in thyrotropin output initiates an outpouring of thyroid hormone into the blood. This in turn acts to suppress the secretion of thyrotropin by the pituitary and, correspondingly, thyroid activity is diminished. A self-regulating system is thus postulated in which the pituitary has a similar role to that of a thermostat. The pituitary-thyroid relationship, in other words, is thought to be a form of servo or feed-back mechanism (1). If the foregoing assumption is correct, then Graves' disease or hyperactivity of the thyroid could as well be the result of a derangement of the pituitary portion of t...
Probing Amyloid Fibril Growth by Two-Dimensional Near-Ultraviolet Spectroscopy

Keeping track of the aggregation kinetics of amyloid fibrils is essential for understanding their formation mechanism and eventually developing treatments for misfolded protein-related diseases. A simulation study of a series of Aβ9–40 amyloid fibrils with different size, shows that novel two dimensional near-ultraviolet (2DNUV) spectra contain characteristic signatures of interactions between peptides. Chiral 2DNUV signals show a larger degree of exciton delocalization compared to their non-chiral counterparts. Intensities of specific peaks provide a direct measure of the number of peptides in a fibril. These signals could be used to monitor the fibril growth kinetics, one peptide at a time.
A Guided Tour through Data-center Networking: A good user experience depends on predictable performance within the data-center network.

The magic of the cloud is that it is always on and always available from anywhere. Users have come to expect that services are there when they need them. A data center (or warehouse-scale computer) is the nexus from which all the services flow. It is often housed in a nondescript warehouse-sized building bearing no indication of what lies inside. Amidst the whirring fans and refrigerator-sized computer racks is a tapestry of electrical cables and fiber optics weaving everything together -- the data-center network. This article provides a "guided tour" through the principles and central ideas surrounding the network at the heart of a data center -- the modern-day loom that weaves the digital fabric of the Internet.
Tenacious Persisters: Returning Adult Students in Higher Education:

We identify “tenacious persisters” as returning students who have stopped out of college or who delayed their entry into college for more than three years after high school. Using a mixed method approach, we compare the experiences of tenacious persisters enrolled in a community college to students who followed more standard persistence paths. Both groups have similar motivations for attending college at this point in their lives, and similar expectations for achieving their goals. Tenacious persisters, however, attribute much more significance to barriers and personal deficiencies in explaining their past attendance patterns. We conclude that how students persist either as tenacious persisters or standard persisters seems to make a difference in how they view their current attempt at college and the obstacles they may have overcome to be there.
Optimal loading rates and economic analyses for anaerobic digestion of poultry waste.

ABSTRACT Four combinations of litter and carcasses from broiler chickens were examined utilizing a thermophilic, stirred-tank digester of demonstration size of approximately 10,000 gal. Under computed optimal loading rates, litter with paper bedding had the highest daily production of methane over an 8-day retention period. The greatest methane production per lb of volatile solids was achieved over 10 days with litter and paper bedding combined with carcasses. This research found that sufficient poultry litter is generated within 20 mi (32 km) of Moorefield, WV, to support a commercial-sized digester operation. However, anaerobic digestion of poultry waste cannot be financially supported by methane production alone. To be financially viable, anaerobic digestion requires a disposal fee for poultry waste and/or the sale of the digested solid effluent as an organic fertilizer to retail markets.
Exploring neighborhood-level variation in asthma and other respiratory diseases: the contribution of neighborhood social context.

OBJECTIVE: We explore differences in the prevalence of asthma and other respiratory diseases at the neighborhood level. In addition to traditional metrics of neighborhood structure (e.g., concentrated disadvantage, residential stability), we incorporate residents’ evaluations of neighborhood context. We examine the extent to which indicators such as disorder (observable signs of physical and social decay) and collective efficacy (trust and shared expectations for beneficial community action) account for differences in the prevalence of asthma and other respiratory diseases. METHODS: We examine 338 Chicago neighborhoods, combining 3 data sources from the 1990s: 1) the Metropolitan Chicago Information Center Metro Survey; 2) the Decennial Census; and 3) the Project on Human Development in Chicago Neighborhoods Community Survey. We use a multilevel statistical approach to disentangle neighborhood- from individual-level effects. MEASUREMENTS: A survey-based response to whether a physician has diagnosed asthma, bronchitis, emphysema, or other breathing problems. RESULTS: Findings indicate that individual- and neighborhood-level factors are associated with asthma/breathing problems. At the individual level, female gender, smoking, and a weight problem are positively associated with asthma/breathing problems, while Latino ethnicity is protective. At the neighborhood level, collective efficacy is protective against asthma/breathing problems. Residential stability is positively associated only when levels of collective efficacy are controlled. CONCLUSIONS: Neighborhood context, particularly collective efficacy, may be an underlying factor that reduces vulnerability to asthma and other respiratory diseases. Collective efficacy may enhance the ability to garner health-relevant resources, eliminate environmental hazards that trigger asthma, and promote communication among residents which, in turn, enables dissemination of information relevant to respiratory ailments.
A generalization of the concept of impedance and a novel Walsh domain immittance

This paper deals with generalized solution methods for AC power circuits. The motivation is to explore more efficient numerical solutions of power distribution circuits subject to electronic loads. Two main points are presented: a generalization of Ohm's law; and the use of the Walsh domain (as opposed to the frequency or Fourier domain) for calculations. With regard to the latter, a Walsh domain matrix similar to the bus impedance matrix is proposed. The matrix may be used to identify potential system resonances. The proposed application area for these techniques is in electric power distribution. >
Media Effects and Communication Bias in Diverse Groups

Abstract This paper extends research on factors influencing effective communication in diverse groups. The effects of social group membership on attention and influence were examined using 17 groups of three men and three women. Each group discussed a controversial topic face-to-face or using either an anonymous or an identified group support system environment. Social group membership biased both attention and influence; these effects were eliminated when discussions were conducted electronically—even when social group membership of participants was identifiable in the electronic media.
Does Cream-Skimming Curdle the Milk? A Study of Peer Effects.

Abstract The determinants of education quality remain a puzzle in much of the literature. In particular, no one has been able to isolate the effect of the quality of a student's peers on achievement. I identify this by considering the introduction of a magnet school into a school district. The magnet school selects high quality students from throughout the school district, generating plausibly exogenous variation in the quality of classmates remaining to those students in the regular schools. I find that the loss of high ability peers lowers the performance of low-scoring students remaining in regular schools.
Timing and nature of tertiary plutonism and extension in the Grouse Creek Mountains, Utah

The Grouse Creek-Albion-Raft River metamorphic core complex in northwestern Utah and southern Idaho is characterized by several Tertiary plutons with a range of ages and crosscutting relations that help constrain the timing of extensional deformation. In the Grouse Creek Mountains, at least three distinct, superimposed, extension-related Tertiary deformational events are bracketed by intrusive rocks, followed by a fourth event: motion on range-bounding faults. The Emigrant Pass plutonic complex was emplaced at depths of less than 10 km into Permianage rocks. SHRIMP U-Pb zircon analysis indicates a three-stage intrusion of the complex at 41.3 ± 0.3 Ma, 36.1 ± 0.2 Ma, and 34.3 ± 0.3 Ma. The two youngest phases represent distinctly younger intrusive event(s) than the oldest phase, separated by more than 5 m.y. The oldest phase cuts several metamorphosed and deformed younger-on-older faults, providing a pre-41 Ma age bracket for oldest extension-related deformation in the region. The youngest phase(s) are int...
Paleo-environmental perspectives on the Sahel drought of 1968–73

A review of stream, dune and lake phenomena in several well-studied sectors of the Sahel indicates an informative record of repeated environmental change. Blowing sand encroached far into the now semi-arid savanna between approximately 20,000 and 12,500 years ago, which lakes had substatially greater volumes and rivers higher discharges between 9000 and 5000 years ago. But rapid change and high-amplitude variability have always been the rule. During the last 2500 years conditions fluctuated about the modern median, with strong short and medium-term oscillations. The Sahel drought after 1968 falls within the norm of at least 6 earlier, dry anomalies verfied since 1400 AD. Whether or not the coincidence of cumulative overgrazing and population pressure with severe drought has triggered a geomorphologic response that is unique in the record, can only be decided after much more systematic work has been carried out.
Speaking Out of Both Sides of Their Mouths

The ideologically objectionable premise model posits that biased political judgments can emerge across the political spectrum. Previous tests of ideological differences in political judgment biases have utilized between-subjects designs (i.e., separate comparisons). In this study (N = 410), we examined whether these biases also emerge in within-subjects designs (i.e., joint comparisons) and compared the strengths of judgment biases in between-subjects and within-subjects designs. Across designs, both liberals and conservatives favored sympathetic over unsympathetic targets in scenario judgments, but biases were attenuated in the within-subjects design. No ideological differences in bias strength emerged, although liberals reported a stronger internal motivation to respond without prejudice toward ideologically dissimilar others. Further, consistent with the ideological conflict hypothesis, both liberals and conservatives were prejudiced toward ideologically dissimilar targets, although biases in prejudice...
Complete Interruption of the Aortic Arch

The clinical, hemodynamic, angiographic, and pathologic findings in three patients with complete interruption of the aortic arch are presented. In addition, data derived from published reports of 52 previous patients are summarized. This malformation is never an isolated one, since a patent ductus arteriosus is always present and a ventricular septal defect is almost invariably found as well. The diagnosis of absence of the aortic arch is difficult, since differential cyanosis is uncommon, relative systolic hypertension of the arms is rare, and the heart murmur, when present, is of a nonspecific nature. At catheterization the pressure in the pulmonary artery, patent ductus arteriosus, and descending aorta is usually similar to that in the ascending aorta and in its branches. Selective angiocardiography has been shown to be the only means of establishing the presence of the malformation prior to operation or autopsy. Since the majority of patients with absence of the aortic arch die within the month following birth, early recognition of the lesion is imperative if surgical correction is to be of benefit.
Electronic origin of void formation in fcc metals

Voids can be formed by supersaturation of vacancies created by energetic particle irradiation, quenching, or mechanical deformation. By using multiscale simulations, we studied the thermodynamic processes of void formation in Al. We discovered an important connection between vacancy-induced bonding cage and the tendency of void formation in fcc metals. A model is proposed to explain the observed connection, linking the electronic structure to the free energy of a void nucleus. We found that the formation of the bonding cages is closely related to the directionality of the chemical bonding in fcc metals.
Performance during the First Year of College: Differences Associated with Learning Style

Among 149 second-year students the 59 who scored as assimilators on Kolb's Learning Style Inventory reported higher course grades (GPA) in their first year of college.
A Statistical Analysis of the Theoretical Yield of Ethanol from Corn Starch

This paper analyzes the Illinois State Variety Test results for total and extractable starch content in 708 samples of 401 commercial varieties of corn. It is shown that the normally distributed extractable starch content has the mean of 66.2% and the standard deviation of 1.13%. The corresponding maximum theoretical yield of ethanol is 0.364 kg EtOH/kg dry corn, and the standard deviation is 0.007. In the ethanol industry units, this yield translates to 2.64 gal EtOH/nominal wet bushel, and the standard deviation is 0.05 gal/bu. The U.S. ethanol industry consistently has inflated its ethanol yields by counting 5 volume percent of # 14 gasoline denaturant (8% of energy content) as ethanol. Also, imports from Brazil and higher alcohols seem to have been counted as U.S. ethanol. The usually accepted USDA estimate of mean ethanol yield in the U.S., 2.682 gal EtOH/bu, is one standard deviation above the rigorous statistical estimate in this paper.
Developmental study on the regulation of neurotransmitter-sensitive adenylate cyclase systems in primary cerebral cell cultures from embryonic mice.

An ontogenetic study of the effect of various neuhormones and other activators on adenylate cyclase systems was carried out using cultures of ceils from 15-d-old embryonic mouse brain. Dopamine stimulated the enzyme activity at earlier culture ages (i.e. 4 and l0 d) but had little stimulatory effect at later ages (i.e. 20 and 33 d). Further, this stimulation at the earlier ages was blocked by the dopaminergic blocker, fluphenazine, but not by α and β-adrenergic antagonists. In contrast to dopamine, isoproterenol (a β-adrenergic agonist) had little stimulatory effect at earlier ages, but its ability to stimulate cyclase activity increased with age. This increase in all age groups was blocked by propranolol ( afg - adrenergic antagonists) . Epinephrine-sensitive enzyme activity showed a steady increase with age, which could be blocked with propranolol except in β-d-old cultures, where it was blocked instead by fluphenazine. Because the cultures are relatively enriched in neurons at earlier ages and in glia in later ages, the results suggest a predominantly neuronal localization for the dopamine sensitive adenylate cyclases and a glial localization of the isoproterenol and epinephrine sensitive adenylate cyclases. Histamine, serotonin, calcium/calmodulin and chloroadenosine were either only slightly or not at all stimulatory.
On Advice for Beginners in Statistical Research

Editor's Note: In the May 2004 TAS, Hamada and Sitter provided advice for the statistics graduate student on doing research. We asked several prominent statistics researchers to discuss this article, and TAS readers were also invited to contribute discussion. In the following articles, we get some personal insight on how statisticians do research, and we also see that research is an activity for all statisticians, not just the ones in academia. ?James Albert, Editor, The American Statistician
Calibration of high performance size exclusion chromatography for small epoxy molecules

Abstract Many epoxy resin formulations contain small oligomers (e.g., less than 1000 molecular weight units) as left over starting materials, reaction by products, or as active parts of the formulation. Modern high performance size exclusion columns are available which enable molecular weights of these oligomers to be determined if proper calibration techniques are employed. Data are presented which demonstrate the differences in calibration curves for epoxy molecules and polystyrene standards, n-alkanes, and phthalate esters for molecular weights under 1000 g/mole. Low MW epoxies are used to calibrate directly for epoxies rather than using molecular size conversion factors calculated from other standards such as polystyrenes.
Promoting U.S. census data in an academic environment: opportunities and challenges.

The availability of demographic and economic data from the U.S. Census in CD-ROM format improves access to the data and presents new opportunities for students and other researchers to use it. The library at Montana State University, Bozeman, a selective federal depository, a state data center affiliate, and member of the Bureau of the Census' Business and Industry Data Center program (BIDC), has undertaken structured efforts to promote wider use of census data among students, faculty, and the university community. Several workshops and instructional sessions are described, focusing on ways to introduce faculty, institutional researchers, and students to U.S. Census data and similar information related to their course assignments and research interests. Handouts for the faculty/staff and student sessions are included, illustrating the organization of the presentations and the integration of U.S. Census and related information sources into library instruction sessions. These teaching and promotional activities are described in the context of budgetary and service issues faced by libraries providing access to census data in electronic formats, particularly federal depository libraries. The success of these efforts is assessed, and libraries' response to new expectations for service is also discussed.
A profile of directors of clerkships in Obstetrics and Gynecology in the United States and Canada

Objective: To describe current professional activities, demographic profiles, and attitudes of directors of clerkships in university and community teaching sites. Methods: Written surveys were mailed to departments of obstetrics and gynecology in the United States and Canada. Results were analyzed for differences in demographics, professional activities, and responses to statements describing career development of medical teachers and levels of institutional support. Results: Responses from 132 of 148 (89%) medical schools and 67 of 96 (70%) known community-based clerkship directors showed no significant differences between the two groups in demographics or professional responsibilities. Three-quarters were men. The mean age was 47 years, mean duration as a faculty member 11 years, and mean tenure as clerkship director 8 years. One-half had been a clerkship director less than 5 years. The average clerkship director reported working approximately 56 hours per week, of which 44% was devoted primarily to patient care, 24% to teaching, and 18% to administration. These faculty members describe the activities of their position as fulfilling and worthy of recognition in the academic promotions process. Conclusion: Directors of clinical clerkships in obstetrics and gynecology in both university- and community-based programs spend about one-half of their time in teaching and administration. They find their work fulfilling and worthwhile. Profiles are consistent over time and comparable to those described by clerkship directors in other specialties.
A signal processing model of diagnostic x-ray scatter.

A model of scatter is developed from a signal processing approach. The scattering process is viewed as a nonlinear filter (NLF), which transforms a two‐dimensional signal representing phantom thickness into a two‐dimensional signal of scattered radiation. The NLF point spread function (PSF) is derived from a single scattering model, using the principles of Compton scattering and x‐ray attenuation. The PSF is characterized by three approximations: a constant geometric shape, a volume that depends on the phantom thickness, and a width that depends on the phantom‐to‐detector distance. This leads to a closed form expression for the scatter‐to‐primary ratio as a function of phantom thickness, field size,photon energy, source‐to‐phantom distance, and phantom‐to‐detector distance. The NLF model is compared with previously reported measurements using constant thickness phantoms, and discrepancies are discussed. The good agreement found between the NLF model and measured data shows that the functional dependence of scatter on the above parameters, previously only explained in terms of empirical models or Monte Carlo simulations, can be incorporated into a signal processing model.