cssi/SciSciGPT-SciSciNet huggingface dataset:
Dynamic growth metrics for examining prenatal exposure impacts on child growth trajectories: Application to perfluorooctanoic acid (PFOA) and postnatal weight gain

Abstract Background Epidemiologic studies investigating prenatal exposures in relation to growth typically rely on cumulative growth measures such as weight or BMI. However, less is known about how prenatal exposure may impact other aspects of growth dynamics, including timing and velocity. Objectives To describe and apply a nonlinear growth model previously used in other health science fields to characterize postnatal growth trajectories for use in environmental epidemiology studies. Methods We used a double logistic function to model child weight trajectories from birth to 5.5 years using data from the Swedish Environmental Longitudinal Mother and Child, Asthma and Allergy (SELMA) study. From this, we approximated several infant growth metrics: 1) duration of time needed to complete 90% of the infant growth spurt (Δt1), 2) the maximum growth rate in infancy or infant peak growth velocity (PGV), 3) the age at infant PGV (δ1), a measure of growth tempo, and 4) the weight plateau at the end of the infant growth spurt (α1). We assessed these metrics in relation to prenatal perfluorooctanoic acid (PFOA) exposure among 1334 mother-child pairs, and differences between boys and girls. Results Average estimated infant PGV and its timing (δ1) were 0.68 kg/month and 3.4 months, respectively. Mean infant growth spurt duration (Δt1) was 13 months, ending at an average weight plateau (α1) of 8.2 kg. Higher prenatal PFOA concentrations were related to a longer duration of infant growth (Δt1: 0.06; 95% CI = 0.01, 0.11). PGV was not impacted, but higher prenatal PFOA concentrations were significantly related to delayed infant PGV (δ1: 0.58; 95% CI = 0.17, 0.99) and a higher post-spurt weight plateau (α1: 0.81; 95% CI = 0.21, 1.41). After adjusting for false discovery, results were only significant for δ1 and α1. We observed a significant interaction by sex for the association with δ1, and stratified analyses revealed the association was only significant among girls. Conclusion Model-derived growth metrics were consistent with published growth standards. This novel application of nonlinear growth modeling enabled detection of altered infant growth dynamics in relation to prenatal PFOA exposure. Our results may help describe how PFOA yields lower birthweights, but higher weight later in childhood. Future applications may characterize adolescent growth or additional metrics of biological interest.
A hybrid lipid membrane coating “shape-locks” silver nanoparticles to prevent surface oxidation and silver ion dissolution

The controlled synthesis of stable silver nanoparticles (AgNPs), that do not undergo surface oxidation and Ag+ ion dissolution, continues to be a major challenge. Here the synthesis of robust hybrid lipid-coated AgNPs, comprised of L-α-phosphatidylcholine (PC) membranes anchored by a stoichiometric amount of long-chained hydrophobic thiols and sodium oleate (SOA) as hydrophobic binding partners, that do not undergo surface oxidation and Ag+ ion dissolution, is described. UV-Visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), and inductively coupled plasma mass spectrometry (ICP-MS) demonstrate that in the presence of strong oxidants, such as potassium cyanide (KCN), the hybrid lipid-coated AgNPs are stable and do not undergo surface oxidation even in the presence of membrane destabilizing surfactants. UV-Vis studies show that the stability of hybrid lipid-coated AgNPs of various sizes and shapes is dependent on the length of the thiol hydrocarbon chain and can be ranked in the order of increasing stability as follows: propanethiol (PT) < hexanethiol (HT) ≤ decanethiol (DT). UV-Vis and ICP-MS studies show that the hybrid lipid-coated AgNPs do not change in size or shape confirming that the AgNPs do not undergo surface oxidation and Ag+ ion dissolution when placed in the presence of strong oxidants, chlorides, thiols, and low pH. Long-term stability studies, over 21 days, show that the hybrid lipid-coated AgNPs do not release Ag+ ions and are more stable. Overall, these studies demonstrate hybrid membrane encapsulation of nanomaterials is a viable method for stabilizing AgNPs in a “shape-locked” form that is unable to undergo surface oxidation, Ag+ ion release, aging, or shape conversion. More importantly, this design strategy is a simple approach to the synthesis and stabilization of AgNPs for a variety of biomedical and commercial applications where Ag+ ion release and toxicity is a concern. With robust and shielded AgNPs, investigators can now evaluate and correlate how the physical features of AgNPs influence toxicity without the confounding factor of Ag+ ions present in samples. This design strategy also provides an opportunity where the membrane composition can be tuned to control the release rate of Ag+ ions for optimizing antimicrobial activity.
Pacific push into the Atlantic

Deep, carbon-rich Pacific waters intruded into the South Atlantic some 38 to 28 thousand years ago. This deep Pacific expansion could have represented a considerable sink of atmospheric CO2, one that helped initiate the Last Glacial Maximum.
Using diagnostic stewardship to reduce rates, healthcare expenditures and accurately identify cases of hospital-onset Clostridioides difficile infection.

Objective: Lack of judicious testing can result in the incorrect diagnosis of Clostridioides difficile infection (CDI), unnecessary CDI treatment, increased costs and falsely augmented hospital-acquired infection (HAI) rates. We evaluated facility-wide interventions used at the VA San Diego Healthcare System (VASDHS) to reduce healthcare-onset, healthcare-facility–associated CDI (HO-HCFA CDI), including the use of diagnostic stewardship with test ordering criteria. Design: We conducted a retrospective study to assess the effectiveness of measures implemented to reduce the rate of HO-HCFA CDI at the VASDHS from fiscal year (FY)2015 to FY2018. Interventions: Measures executed in a stepwise fashion included a hand hygiene initiative, prompt isolation of CDI patients, enhanced terminal room cleaning, reduction of fluoroquinolone and proton-pump inhibitor use, laboratory rejection of solid stool samples, and lastly diagnostic stewardship with C. difficile toxin B gene nucleic acid amplification testing (NAAT) criteria instituted in FY2018. Results: From FY2015 to FY2018, 127 cases of HO-HCFA CDI were identified. All rate-reducing initiatives resulted in decreased HO-HCFA cases (from 44 to 13; P ≤ .05). However, the number of HO-HCFA cases (34 to 13; P ≤ .05), potential false-positive testing associated with colonization and laxative use (from 11 to 4), hospital days (from 596 to 332), CDI-related hospitalization costs (from 1,476) decreased substantially following the introduction of diagnostic stewardship with test criteria from FY2017 to FY2018. Conclusions: Initiatives to decrease risk for CDI and diagnostic stewardship of C. difficile stool NAAT significantly reduced HO-HCFA CDI rates, detection of potential false-positives associated with laxative use, and lowered healthcare costs. Diagnostic stewardship itself had the most dramatic impact on outcomes observed and served as an effective tool in reducing HO-HCFA CDI rates.
Nonlinear Synchronization Control for Short-Range Mobile Sensors Drifting in Geophysical Flows

This paper presents a synchronization controller for mobile sensors that are minimally actuated and can only communicate with each other over a very short range. This work is motivated by ocean monitoring applications where large-scale sensor networks consisting of drifters with minimal actuation capabilities, i.e., active drifters, are employed. We assume drifters are tasked to monitor regions consisting of gyre flows where their trajectories are periodic. As drifters in neighboring regions move into each other's proximity, it presents an opportunity for data exchange and synchronization to ensure future rendezvous. We present a nonlinear synchronization control strategy to ensure that drifters will periodically rendezvous and maximize the time they are in their rendezvous regions. Numerical simulations and small-scale experiments validate the efficacy of the control strategy and hint at extensions to large-scale mobile sensor networks.
Training in Neurology: Diagnostic Accuracy Among Neurology Residents: The "Close the Loop" Project

Objective To describe cases presented by junior neurology residents, and to evaluate resident diagnostic patterns to help address individual and systemic educational needs. Methods For 6 academic years, details of all morning report cases assessed and presented by junior neurology residents were logged, including the resident9s independent initial diagnostic impression. Cases were later revisited at subsequent morning reports to “close the loop” on a final diagnosis. We conducted retrospective review to quantify case demographics and to determine resident diagnostic accuracy based on pre-specified localization pathways. Results Demographic analysis included 1,472 cases; of these, 1,301 qualified for accuracy analysis due to diagnostic uncertainty at time of morning report. Non-neurologic etiologies represented 26.0% of cases. Central nervous system etiologies were the majority (86.0%) of neurologic cases. The most frequent diagnoses were ischemic stroke and seizure. Overall resident diagnostic accuracy was 64.0%. Accuracy was similar between central and peripheral etiologies. Of 1,301 cases, 15.3% were overcalled as neurologic, while neurologic disease was rarely mistaken as non-neurologic (5.1%). Most diagnostic errors (49.1%) occurred when determining if a case was neurologic. Where in the localization pathway errors occurred varied between etiologies. Conclusion Overall diagnostic accuracy for neurology junior residents in our cohort was similar to prior work conducted in smaller samples. Analysis of errors, particularly at the critical “neurologic or non-neurologic” decision-point, warrants further investigation. “Close the loop” methodology is simple to employ and can guide educational and quality initiatives to improve neurology resident clinical acumen.
Understanding the barriers and facilitators to safe infant sleep for mothers of preterm infants

To identify barriers and facilitators to adherence to safe sleep practices (SSP) among mothers of preterm infants using qualitative methodology. We conducted 23 in-depth interviews in English or Spanish with mothers of preterm infants who were recently discharged from four hospitals, utilizing a grounded-theory approach and framework of the Theory of Planned Behavior (attitudes, perceived control, social norms). For attitudes, mothers’ fear about their infants’ vulnerable preterm state related to suffocation, apnea of prematurity, and reflux influenced infant sleep practices. For social norms, education received in the NICU and advice from other health care providers, family, friends, and media impacted their choices. For perceived control, mothers adapted infant sleep practices to meet their own needs and address the perceived safety and comfort of infants. Factors identified that influence maternal decision-making about infant sleep practices can inform interventions to address sudden unexpected infant death reduction in preterm infants.
The Geriatric Acute and Post-Acute Fall Prevention Intervention (GAPcare) II to Assess the Use of the Apple Watch in Older Emergency Department Patients With Falls: Protocol for a Mixed Methods Study.

Background: Falls are a common problem among older adults that lead to injury, emergency department (ED) visits, and institutionalization. The Apple Watch can detect falls and alert caregivers and clinicians that help is needed; the device could also be used to objectively collect data on gait, fitness, and falls as part of clinical trials. However, little is known about the ease of use of this technology among older adult ED patients, a population at high risk of recurrent falls. Objective: The goal of this study—the Geriatric Acute and Post-Acute Fall Prevention Intervention (GAPcare) II—is to examine the feasibility, acceptability, and usability of the Apple Watch Series 4 paired with the iPhone and our research app Rhode Island FitTest (RIFitTest) among older adult ED patients seeking care for falls. Methods: We will conduct field-testing with older adult ED patients (n=25) who sustained a fall and their caregivers (n=5) to determine whether they can use the Apple Watch, iPhone, and app either (1) continuously or (2) periodically, with or without telephone assistance from the research staff, to assess gait, fitness, and/or falls over time. During the initial encounter, participants will receive training in the Apple Watch, iPhone, and our research app. They will receive an illustrated training manual and a number to call if they have questions about the research protocol or device usage. Participants will complete surveys and cognitive and motor assessments on the app during the study period. At the conclusion of the study, we will solicit participant feedback through semistructured interviews. Qualitative data will be summarized using framework matrix analyses. Sensor and survey response data will be analyzed using descriptive statistics. Results: Recruitment began in December 2019 and was on pause from April 2020 until September 2020 due to the COVID-19 pandemic. Study recruitment will continue until 30 participants are enrolled. This study has been approved by the Rhode Island Hospital Institutional Review Board (approval 1400781-16). Conclusions: GAPcare II will provide insights into the feasibility, acceptability, and usability of the Apple Watch, iPhone, and the RIFitTest app in the population most likely to benefit from the technology: older adults at high risk of recurrent falls. In the future, wearables could be used as part of fall prevention interventions to prevent injury before it occurs. Clinical Trial: ClinicalTrials.gov NCT04304495; https://clinicaltrials.gov/ct2/show/NCT04304495
Effect of intra-arterial vasodilator administration during radial artery access on systemic blood pressure in patients receiving moderate sedation.

Purpose:The hemodynamic effects of intra-arterial vasodilator administration for the prevention of radial artery spasm during transradial access have not been well characterized. This study evaluat...
Walking speed declines with age in male and female baboons (Papio sp.): Confirmation of findings with sex as a biological variable.

We measured walking speed in baboons (67 female, 36 male; 5-22 years) to develop regression formulas to predict biological age. The final model strongly predicted age from just speed and sex. Walking speed is a valuable baboon aging biomarker. We present the first male speed data in a nonhuman primate.
Early Warning of Resistance to Bt Toxin Vip3Aa in Helicoverpa zea

Evolution of resistance by pests can reduce the benefits of crops genetically engineered to produce insecticidal proteins from Bacillus thuringiensis (Bt). Because of the widespread resistance of Helicoverpa zea to crystalline (Cry) Bt toxins in the United States, the vegetative insecticidal protein Vip3Aa is the only Bt toxin produced by Bt corn and cotton that remains effective against some populations of this polyphagous lepidopteran pest. Here we evaluated H. zea resistance to Vip3Aa using diet bioassays to test 42,218 larvae from three lab strains and 71 strains derived from the field during 2016 to 2020 in Arkansas, Louisiana, Mississippi, Tennessee, and Texas. Relative to the least susceptible of the three lab strains tested (BZ), susceptibility to Vip3Aa of the field-derived strains decreased significantly from 2016 to 2020. Relative to another lab strain (TM), 7 of 16 strains derived from the field in 2019 were significantly resistant to Vip3Aa, with up to 13-fold resistance. Susceptibility to Vip3Aa was significantly lower for strains derived from Vip3Aa plants than non-Vip3Aa plants, providing direct evidence of resistance evolving in response to selection by Vip3Aa plants in the field. Together with previously reported data, the results here convey an early warning of field-evolved resistance to Vip3Aa in H. zea that supports calls for urgent action to preserve the efficacy of this toxin.
A single center's 15-year experience with palliative limb care for chronic limb threatening ischemia in frail patients.

ABSTRACT OBJECTIVE Our institution’s multidisciplinary Prevention of Amputation in Veterans Everywhere (PAVE) program allocates veterans with critical limb threatening ischemia (CLTI) to immediate revascularization, conservative, primary amputation or palliative limb care based on previously published criteria. These four groups align with the approaches outlined by the Global Guidelines for management of CLTI. The current study delineates the natural history of the palliative limb care group of patients and quantifies procedural risks and outcomes. METHODS Veterans prospectively enrolled into the palliative limb cohort of our PAVE program between January 2005 and January 2020 were analyzed. The primary outcome was mortality. Secondary outcomes included overall and limb-related readmissions, limb loss and wound healing. Clinical Frailty Score (CFS) was calculated and 5-year expected mortalities were estimated using the Veterans Administration Quality Enhancement Research Initiative (VA QUERI) tool. Regression analysis was performed to establish associations among the following variables: mortality, WIfI score, Clinical Frailty Score, overall admissions and limb-related admissions. RESULTS The PAVE program enrolled 1158 limbs over 15 years. 157 (13.5%) limbs in 145 patients were allocated to the palliative limb care group. The overall mortality of the group was 88.2% (median 3.5 months; range 0-91 months). Of the patients that expired, 50% (n=64) died within 3 months of enrollment. The predicted 5-year mortality for the group was 66%. The average frailty score of the group was 6.2, denoting someone who is moderately to severely frail. Based on CFS, 106 patients were considered frail while 39 were considered not frail. There was no difference in mortality between frail and non- frail patients, however there was a statistically significant difference in early mortality ( CONCLUSION Frail, chronic limb threatening ischemia patients have a high early mortality and a low risk of limb-related complications. They also have a low incidence of deferred primary amputation or limb-related readmissions. In our cohort, the vast majority of patients died within a few months of enrollment without needing an amputation. A comprehensive approach to the management of CLTI patients should include a palliative limb care option as a significant proportion of these patients have limited survival and can potentially avoid unnecessary surgery or major amputation.
Toileting Behaviors and Lower Urinary Tract Symptoms: A Cross-sectional Study of Diverse Women in the United States

Abstract Background Toileting behaviors are increasingly recognized as factors potentially contributing to development of lower urinary tract symptoms (LUTS). Objectives To examine adult women's toileting behaviors and LUTS across age and race/ethnicity groups and relationships between toileting behaviors and LUTS. Design Planned secondary analysis of questionnaire data collected in a focus group study on bladder health. Settings Questionnaires were completed at the conclusion of focus groups conducted in community settings affiliated with seven research centers across the United States. Participants Community-living women regardless of LUTS status. Methods Forty-four focus groups were conducted with 360 adolescent and adult cisgender women. After each focus group, participants completed questionnaires to assess toileting behaviors (Toileting Behaviors-Women's Elimination Behaviors Scale (TB-WEB)) and their experience of LUTS (Lower Urinary Tract Symptom Tool), This analysis includes quantitative data from the subgroup of 316 participants who completed the questionnaires. Results Participants ranged in age from 18-93 years (Mean=50.2 years). A significant effect for age was found for delayed voiding behavior, reported by 76.5% of women ages 18-25 years and 21.9% of those 75+ years (p Conclusions These findings highlight the need for research to understand underpinnings of age and racial/ethnic differences in toileting behaviors and identify mechanisms by which toileting behaviors might influence development of LUTS over time. Understanding causal pathways is important in the development of public health interventions to encourage toileting behaviors that support bladder health.
The Neo-Thomist Theory of the Common Good and Catholic Social Teaching

The notion of the common good is among the most durable political ideas in western political thinking, serving as a goal for practice and thus also as a kind of justification. It has its remote origins deep in the tradition of western political philosophy as an aspiration to transcend the narrow interest in one’s own satisfaction that is the essence of tyranny. It is at the root of Plato and Aristotle’s conception of the political itself and is later recontextualized in medieval Christian political theology — seen especially in the thought of Thomas Aquinas — in at least two different modes: as an element of a speculative natural theology according to which the political is a part of the order of divine providence, and in practical discussions of particular moral and political problems. The aspirational sense of the common good remains ubiquitous and explains a good bit of its rhetorical power, but is often little more than a vague injunction or truism, hortatory but without content. A more precise account of the common good has been articulated in the official statements of Roman Catholic social teaching since Pope John XXIII’s 1961 encyclical letter, Mater et magistra and especially in the Second Vatican Council’s 1965 Pastoral Constitution of the Church in the Modern World, Gaudium et spes. Those documents formulate the common good as “the sum total of social conditions which allow people, either as groups or as individuals, to reach their fulfillment more fully and more easily.” This definition can be said to focus on society as a kind of useful good and accordingly puts its moral emphasis on the substantive good beyond the instrument, namely the person. This seems in some respects a difference — is it a difference of emphasis or more one of substance? — from the earlier Thomist view.
Neonatal and adult cardiomyocytes differ in their susceptibility to the proapoptotic protein bnip3 (LB657)

Bnip3 is a BH3-only protein that is upregulated during hypoxic condition and is known to cause cell death in many different cell types. Studies have found that overexpression of Bnip3 in neonatal c...
A Minkowski Type Trace Inequality and Strong Subadditivity of Quantum Entropy

We consider the following trace function on n-tuples of positive operators: $${\Phi _P}({A_1},{A_2},...,{A_n}) = Tr({(\sum\limits_{j = 1}^n {A_j^P} )^{1/P}})$$ and prove that it is jointly concave for 0 2, Фp is neither convex nor concave. We conjecture that Фp is convex for 1 < p < 2, but our methods do not show this.
IFT–Cargo Interactions and Protein Transport in Cilia

The motile and sensory functions of cilia and flagella are indispensable for human health. Cilia assembly requires a dedicated protein shuttle, intraflagellar transport (IFT), a bidirectional motility of multi-megadalton protein arrays along ciliary microtubules. IFT functions as a protein carrier delivering hundreds of distinct proteins into growing cilia. IFT-based protein import and export continue in fully grown cilia and are required for ciliary maintenance and sensing. Large ciliary building blocks might depend on IFT to move through the transition zone, which functions as a ciliary gate. Smaller, freely diffusing proteins, such as tubulin, depend on IFT to be concentrated or removed from cilia. As I discuss here, recent work provides insights into how IFT interacts with its cargoes and how the transport is regulated.
The Alzheimer's Family, by Robert B. Santulli

Approximately 13% of those 65 and older suffer from Alzheimer's disease, and those 85 and older have closer to a 50% chance of being diagnosed with this disease. This number will increase from 5.5 ...
A life course approach to mortality in Mexico

Objective. Research on early life socioeconomic status (SES), education and mortality is less established in developing countries. This analysis aims to determine how SES and education are patterned across the life course and associated with adult mortality in Mexico. Materials and methods. Data comes from 2001-2012 Mexican Health & Aging Study (Mexican adults age 50+, n=11 222). Cox proportional hazard models predict mortality using baseline covariates. Results. In unadjusted analyses, similar mortality was seen across levels of early life SES. Lower early life SES was associated with better survival after accounting for education in the younger cohort. Lower education was only associated with mortality in the younger cohort. Conclusions. Early life SES was associated with education but the relationship between education and mortality differed across cohorts in Mexico. Selective survival and differential returns to education may explain differences.
Surgical Pathology Specimens for Gross Examination Only and Exempt From Submission

Abstract Objective.—To survey the scope of current written institutional policies for types of surgical pathology specimens exempt from submission to the laboratory and those that may be examined by gross inspection only. Design and Setting.—In the first quarter of 1997, a total of 413 voluntary participant institutions enrolled in the College of American Pathologists Q-Probes quality improvement program completed a checklist of 115 proffered specimens. Also included was a questionnaire defining demographic, practice, and reimbursement variables. Main Outcome Measures.—The number and types of specimens exempt from submission and submitted for gross examination only based on written institutional policy rather than on unapproved actual practices. Results.—Most institutions had a written policy for types of specimens deemed exempt from submission to pathology (87.1%) and for types of specimens subject to gross examination only (76.6%). There was a wide range of numbers of specimen types with a median number...
Gay and Lesbian Tourists at a Southern U. S. A. Beach Event

Abstract This study examined economic and social impact measures for a random sample of 1272 gay and lesbian tourists on a five-mile section of the Gulf Islands National Seashore near Pensacola, Florida during Memorial Day Weekend, 1994. The findings suggested young, urban, highly-educated gay and lesbian tourists with high household incomes; traveling frequently in groups to new destinations, and reporting large expenditures across the measurement categories. The findings also suggested that gay and lesbian tourists felt it was very important to be “out” (i.e., visible) in the host community, display gay or lesbian symbols, and receive positive media coverage of their presence. Host community reaction to large numbers of gay and lesbian tourists is discussed.
118. Indoleamine 2,3 dioxygenase (IDO1) is a key regulator of depressive-like behavior but not of mechanical hyperalgesia in the spared nerve injury model of neuropathic pain

Chronic pain and depression frequently co-occur. We used the spared nerve injury (SNI) model of neuropathic pain in mice to explore the neuroimmune mechanism of the comorbidity of neuropathic pain and depressive-like behaviors. SNI induces both mechanical hyperalgesia and depressive-like behavior assessed as reduced social interaction and increased immobility in the forced swim test. These behavioral responses were associated with increased IL-1beta mRNA in the contralateral frontal cortex, ipsilateral lumbar dorsal horn and liver. Daily intrathecal injection of IL-1RA inhibited mechanical hyperalgesia and depressive-like behavior. IL-1RA also abrogated SNI-induced increases IL-1beta and in microglial activation. Peripheral inflammation-induced depressive-like behavior is mediated via increased expression of the indoleamine 2,3-dioxygenase1(IDO1), which catalyzes the conversion of tryptophan to kynurenine. SNI surgery increases the kynurenine/tryptophan ratio in plasma. Concomitantly, IDO1 mRNA expression was increased in liver but not in brain or spinal cord. Intrathecal IL-1RA prevented the increase in liver IDO1mRNA in SNI mice. Importantly, genetic deletion of IDO1 prevented the SNI-induced depressive like behaviors without affecting the pain response. Spinal cord IL-1β signaling is key for both SNI-induced pain and depressive-like behaviors. In contrast, IDO1 activity only contributes to SNI-induced depressive behaviors. Our finding that SNI induces an increase in IDO1 in the liver and not in the brain indicates that IDO controls SNI-induced depressive-like behavior through a peripheral-to-brain pathway. Supported by NIH grants NS083939 and NS074999.
Unified Panel Flutter Theory with Viscous Damping Effects

The idea of a unified panel flutter theory, investigated previously by the author, is amplified to make the inclusion of damping effects possible. The paper attempts to study the combined effects of the aerodynamic and structural types of damping on the flutter boundaries for simply supported panels in high supersonic Mach number flows. Classical plate theory and two-dimensional first-order aerodynamics are used. A closed-form rather than modal approach is used in the solution of the partial differential equation in the analysis to avoid convergence problems. The standing and traveling wave theories of panel flutter are compared. The dual nature of damping (stabilizing and destabilizing) is exposed. While the trends are similar to those already established for isotropic panels, the variables compared are generically defined to account for both the isotropic as well as the orthotropic properties of the panels.
SiGe heterojunctions: devices and applications

SiGe alloys have been successfully to a number of semiconductor devices, including bipolar heterojunction transistors, field effect transistors (FET's), tunneing and optoelectronic devices and structures. This review paper will first summarize the results obtained to-date in bipolar transistors, highlighting the design flexibility and the trade-offs offered by SiGe heterojunction technology an bandgap engineering, like junction field/capacitance control, liquid nitrogen operation and complementary processes. The leverage of this technology in high speed circuits will be discussed, including the record 75 GHz f T and 53 GHz f max heterojunction bipolar transistors, and the achievement of sub-25 ps ECL ring oscillator delay. The applications of this technology to field effect transistors, to increase the channel mobility, to resonant tunneling structures, and to detectors and waveguides, to extend the use of silicon technology in optoelectronic are also reviewed.
Development of a theoretical cost model for advanced composite fabrication

Abstract This paper outlines the development of a theoretical approach to the estimation of processing time for the fabrication of advanced composite parts. The model, termed ‘first-order model’, assumes that all subprocess steps can be modelled as having first-order dynamics. The steps are then linearized and summed according to their ‘extensive’ variables. Part complexity is handled using an information theoretic approach. The result for hand lay-up is a simple linear equation which compares favourably with experiments and with other very detailed cost estimation models. The model is very general, and appears applicable to all additive (composites) as well as subtractive (machining) processes.
Generalization in Decision Research: The Role of Formal Models

A generalization is a working hypothesis, typically expressed in the form of cause-effect relations. Generalizations decay because a) it is difficult to identify appropriate cause-effect relations and b) such relations are sensitive to the influences of environmental conditions. Whereas scientists should be realistic in their aspirations to create generalizable knowledge, much can be done to improve performance through more extensive use of formal models. Two basic types of model are distinguished: replica models and symbolic models. It is particularly important that theories permit comparisons between models and data at multiple levels involving processes, environmental conditions, and predictions. Scientists should avoid the extremes of " models without data" and "data without models." Symbolic models should be subjected to "strong" empirical tests via predictions (rather than tests of statistical significance), and the competing predictions of alternatives. In addition to suggesting what experimental evidence should be collected, it is proposed that symbolic models also serve the important function of determining when data collection would be of little value. The nature of evidence generated by replica models (i. e., experiments) is considered from three viewpoints: 1) asymmetries in the way data and theory interact in affecting conclusions; 2) apparent but illusory conflicts between the goals of internal and external validity; and 3) the importance of conducting experiments despite poor prospects of creating knowledge that can be generalized.
Molecular structure and spectral properties of bromo(2-acetylpyridine4N-methylthiosemicarbazonato)copper(II)

The anion (loss of3N hydrogen) of 2-acetylpyridine4N-methylthiosemicarbazone coordinates in a planar conformation to copper(II) through the pyridyl nitrogen, azomethine nitrogen and thiolato sulphur atoms. The fourth coordination site is occupied by a bromo ligand and the complex is mononuclear and essentially planar. Bond distances and angles, as well as solid state and solution spectral properties, are compared to other recently reported copper(II) thiosemicarbazone complexes.
Randomized Secondary Prevention Trial of Azithromycin in Patients With Coronary Artery Disease and Serological Evidence for Chlamydia pneumoniae Infection The Azithromycin in Coronary Artery Disease: Elimination of Myocardial Infection with Chlamydia (ACADEMIC) Study

Background—Chlamydia pneumoniae commonly causes respiratory infection, is vasotropic, causes atherosclerosis in animal models, and has been found in human atheromas. Whether it plays a causal role in clinical coronary artery disease (CAD) and is amenable to antibiotic therapy is uncertain. Methods and Results—CAD patients (n=302) who had a seropositive reaction to C pneumoniae (IgG titers ≥1:16) were randomized to receive placebo or azithromycin, 500 mg/d for 3 days, then 500 mg/wk for 3 months. Circulating markers of inflammation (C-reactive protein [CRP], interleukin [IL]-1, IL-6, and tumor necrosis factor [TNF]-α), C pneumoniae antibody titers, and cardiovascular events were assessed at 3 and 6 months. Treatment groups were balanced, with age averaging 64 (SD=10) years; 89% of the patients were male. Azithromycin reduced a global rank sum score of the 4 inflammatory markers at 6 (but not 3) months (P=0.011) as well as the mean global rank sum change score: 531 (SD=201) for active drug and 587 (SD=190) ...
Applications of computer-based instruction: using specialized software to aid letter-name and letter-sound recognition

We evaluated computerized training and testing programs with children who were having difficulties learning prereading skills. The programs were derived from equivalence research and were written in authoring software designed for educators. After learning to match uppercase and lowercase printed letters to the corresponding letter names (Tasks 1 and 2), the children matched the letters to one another (Tasks 4 and 5). Then, after learning to match uppercase letters to sounds (Task 3), they also matched lowercase letters to sounds (Task 6) and matched printed to spoken words (Tasks 7 and 8). The results recommend equivalence-based protocols and user-friendly software in further development of prereading instruction.
Ion-exchange resin paper for separation of the acidic urinary metabolites of norepinephrine-2-14C in human subjects

Abstract The acidic urinary metabolites of norepinephrine-2-14C were rapidly and conveniently separated and quantitatively determined by first removing the amines on a CG-50 column, which can be eluted and measured. The unretained normetanephrine conjugate, 3-methoxy-4-hydroxymandelic acid, 3,4-dihydroxymandelic acid and several unknowns are separated on Dowex-1 ion-exchange resin-impregnated paper by developing in the descending direction with 10 M ammonium acetate. After scanning to locate the areas, the radioactive areas are cut out and counted directly in the liquid scintillation counter.
Controlling the Market for Corporate Control: The Historical Significance of Managerial Capitalism

What mode of corporate governance can best enable U.S. industrial enterprises to create value and contribute to national economic prosperity? During the 198Os, amid dramatic changes in the financial structures of major U.S. industrial corporations, many economists extolled the “value-creating” virtues of “the market for corporate control”-the exercise of control over the disposition of corporate assets and revenues by means of financial claims acquired through the medium of public securities markets. 1 A willingness to rely on the market for corporate control to determine the investment strategies of industrial corporations is consistent with the market-oriented ideology of mainstream economics. But, as I shall argue here, the belief in the efficacy of the market for corporate control is inconsistent with the history of successfu1 capitalist development in the United States and abroad over the past century.2 The history of successful capitalist development, marked by changing international industrial leadership, shows that value-creating investment strategies ).Increasingly require that business organizations exercise control over, rather than be controlled by, the market for corporate control. My arguments may be counterintuitive to economists trained to believe that superior economic performance is secured by market coordination rather than organizational (or planned) coordination of econonomic activity. For conventional economists, the “efficient” economy is one in which free markets in labor and capital permit the reallocation of factors of production to their “optimal” uses. From this perspective, any impediments to the “optimal" allocation of scarce resources to alternative uses--at any time and also over time as more efficient uses appear-are deemed to be "market imperfections.”
DIRECT SEEDING OF GRAPEVINE SOMATIC EMBRYOS AND REGENERATION OF PLANTS

Somatic embryos of grapevine (Vitis vinifera L.) ‘Chardonnay’ were produced from liquid suspension cultures. Mature somatic embryos were blot dried briefly in the laminar flow hood and germinated directly in Magenta GA-7 Vessels™ containing one of the following potting media: (1) sand, (2) commercial potting mixture (CPM), or (3) CPM overlaid with sand. Each vessel containing 20 ml of distilled water and the potting medium was sterilized by autoclaving for 30 min and cooled overnight before inoculating the somatic embryos. Five somatic embryos were placed in each vessel under aseptic conditions. The vessels were closed and incubated at 26±2°C, 16 h photoperiod at 75 μmol s−1 m−2 light intensity. Results revealed that CPM overlaid with sand was best for plant development. There was more contamination of somatic embryos on pure CPM. Since direct seeding bypasses at least two subcultures in agar medium, it has implications for use of somatic embryos as ‘synthetic seeds’ for clonal plant production. This study shows that somatic embryos of grapevine can be handled with some of the convenience of seeds, emphasizing the feasibility for further automating in vitro plant production, which might be especially useful for new varieties where propagation material is limited.
Electronic structure calculations of gas adsorption on boron-doped carbon nanotubes sensitized with tungsten

Density-functional theory methods are used to investigate the adsorption of nine prevalent gas molecules (H2, O2, CO, CO2, NO, NO2, H2O, CH3OH, and NH3) on a carbon nanotube-based support material. The support is a boron-doped, single-walled carbon nanotube, which has been sensitized by the adsorption of tungsten metal clusters. Our calculations demonstrate that this hybrid adsorbent material is able to adsorb the gas molecules with varied affinity, and these interactions are characterized by analyzing the features in the projected density-of-states for each system. These calculations represent a critical step in designing high-fidelity sensor materials, selective adsorbents, and more effective catalysts.
Residence time distribution in three-phase monolith reactor

Ceramic honeycomb monoliths have been used as catalyst supports for gas treatment applications, including automobile catalytic converters and NO{sub x} control in flue-gas treatment. The residence time distribution of the liquid phase within a three-phase monolith reactor is determined using tracer studies. The actual liquid residence time in the monolith, relevant for reactor design purposes, is calculated from overall residence time measurements using deconvolution by Fourier transform. The liquid-phase residence time decreases as liquid or gas flow rates increase, but the reactor Peclet number remains approximately constant. The residence time distribution and calculated values of the Peclet number reveal that the liquid phase is substantially well-mixed. Comparison with results from experiments in a single glass capillary reveals that the monolith channels become predominantly liquid-filled, particularly as the liquid flow rate becomes a significant fraction of the total flow rate.
Space Infrared Telescope Facility mission and cryogenic design.

The Space Infrared Telescope Facility is the last of the Great Observatory missions. It is presently scheduled for launch in 2001. The mission will study the infrared spectrum from 2 to 1200 microns with three imaging and spectral instruments. The observatory will have a 5 year lifetime and will be placed in a 100,000 km earth orbit. The cryogenic system is based on a 4000 I superfluid helium cryostat. The mission and the cryogenic system are described, and the cryogenic technology issues are discussed.
Optoelectronic control of spin dynamics at near-terahertz frequencies in magnetically doped quantum wells

We use time-resolved Kerr rotation to demonstrate optical and electronic tuning of both electronic and local moment $({\mathrm{Mn}}^{2+})$ spin dynamics in electrically gated parabolic quantum wells derived from II-VI diluted magnetic semiconductors. By changing either the electrical bias or laser energy, the electron spin precession frequency is varied from 0.1 to 0.8 THz at a magnetic field of 3 T and at a temperature of 5 K. The corresponding range of electrically tuned effective electron $g$-factor is an order of magnitude larger compared with similar nonmagnetic III-V parabolic quantum wells. Additionally, we demonstrate that such structures allow electrical modulation of local moment dynamics in the solid state, which is manifested as changes in amplitude and lifetime of ${\mathrm{Mn}}^{2+}$ spin precession under electrical bias. The large variation of electron and Mn-ion spin dynamics is explained by changes in magnitude of the $sp\text{\ensuremath{-}}d$ exchange overlap.
Effect of age and sex on the composition of muscle and skin from a commercial broiler strain.

1. The effects of age and sex have been studied on the proximate composition and inorganic constituents in breast, thigh, drumstick and skin from a commercial British broiler strain (Ross 1). 2. Protein content generally increased with age in all muscles and decreased in skin. Protein content in skin of males was always higher than that in females. 3. Moisture content in all muscles decreased with age. In the skin, moisture decreased with age considerably more in females than in males. 4. Fat content increased with age in all tissues, while ash content of breast, thigh and skin decreased with age. 5. Phosphorus, chloride, magnesium and potassium all decreased with age in all the tissues. Thigh and skin calcium content were affected by age, as was the sodium content of drumstick and skin. 6. The sex effect on the inorganic constituents was variable.
Effect of feeding tocopherols to dairy cows on the quantity and the fat content of milk produced.

Summary and Conclusions A feeding trial was conducted to determine the effect of supplementing the rations of lactating dairy cows with 1 g. of mixed tocopherols daily per cow on the amount and fat content of the milk produced. Seventeen cows were used, eight of which received basal ration and the remainder received supplemental tocopherol daily from May 21 to July 5, inclusive. Milk from each cow in both groups was weighed and tested for butterfat content daily. Neither the amount nor the fat content of the milk produced appeared to be affected by feeding of the tocopherol supplement. Such supplementation produced no changes in the appearances and appetites of the animals.
Yeast acetyl-CoA carboxylase: in vitro phosphorylation by mammalian and yeast protein kinases.

Abstract Acetyl-CoA carboxylase (ACC) is regulated in mammalian tissues, in part, by multisite enzyme phosphorylation. Yeast ACC (Y-ACC) has been highly purified from S. cerevisiae by monomeric avidin-Sepharose chromatography, revealing an enzyme subunit species of molecular mass 265,000 Da. Unlike mammalian enzyme, Y-ACC is citrate-independent, and reacts weakly or not at all with a panel of anti- rat liver ACC antibodies Like rat ACC, Y-ACC is rapidly phosphorylated and inactivated by two mammalian carboxylase kinases, the cAMP-dependent protein kinase and 5′-AMP-stimulated kinase. It is also phosphorylated by rat liver casein kinase II, but without any change in catalytic activity. Three major yeast protein kinases active on ACC have been fractionated; all co-elute with kinases active on casein, but each appears to be a distinct catalytic species. Like the mammalian casein kinases, however, phosphorylation of ACC by these yeast kinases does not alter yeast ACC activity. Taken together, these data indicate that Y-ACC possesses at least two classes of phosphorylation sites, one or more of which acutely regulates enzyme activity. Alterations in Y-ACC phosphorylation in yeast, as in mammalian tissues, could be an important modulator of the rates of fatty acid synthesis.
Science needs a universal symbol

In the face of irrational opposition, it's time for the scientific community to have its own bumper sticker
Development of letter-specific processing: The effect of reading ability

During development, perceptual processing is tuned to inputs in the environment such that certain frequently encountered classes of stimuli are processed more effectively than similar comparison stimuli. Letters represent a class of stimuli that are encountered frequently in the environment, at least in literate cultures. Thus, the present study examined the development of letter-specific processing in children 6-19 years old by comparing the difference between performance on a letter-matching task and an unfamiliar non-letter-matching task in different subject groups. Results revealed an increase in letter-specific processing with development. Moreover, comparisons of letter-specific processing in groups of subjects matched either in age or reading ability indicate that the emergence of letter-specific processing is linked to increased reading skill, rather than increased age per se. Findings support theories of perceptual expertise, which suggest that skilled processing drives the specialization of perceptual mechanisms for certain classes of stimuli.