cssi/SciSciGPT-SciSciNet huggingface dataset:
Contemporary National Surgical Outcomes in the Treatment of Ureteropelvic Junction Obstruction

Objective To evaluate contemporary national trends and outcomes of open pyeloplasty (OP) vs minimally invasive pyeloplasty (MIP) in the treatment of ureteropelvic junction obstruction using the National Surgical Quality Improvement Program database. Methods Patients treated by OP or MIP between 2006 and 2011 were identified by The International Classification of Diseases, Ninth Revision, Clinical Modification codes corresponding to pyeloplasty as their primary operative procedure. Perioperative variables were analyzed using the chi-square and the Student t test. Multiple logistic regressions were used to identify morbidities and readmission risk factors. Results Three hundred fifty-five patients were identified. Of them, 20.2% of cases were OP and 79.8% were MIP. There was a significant increase in MIP from 33% in 2006 to 83% in 2011 ( P P = .002). Patients treated at a teaching hospital were over 3 times more likely to undergo MIP (odds ratio = 3.17; P = .001). There was significantly longer hospitalization in OP vs MIP (3.9 vs 2.2 days; P = .001). OP was associated with significantly increased risk of reoperation or postoperative morbidity compared with MIP (11.1% vs 4.2%; P = .02). Multivariate analysis confirmed a higher rate of overall morbidity in the OP cohort ( P = .03). Male patients had significantly higher postoperative morbidity or reoperation rates (odds ratio = 4.38; P = .002). There was no significant difference in operative time between groups ( P = .2). Conclusion Within the American College of Surgeons National Surgical Quality Improvement Program hospitals, MIP is associated with decreased reoperation and postoperative morbidity compared with OP.
Eigenvalues of Hadamard powers of large symmetric Pascal matrices

Abstract Let S n be the positive real symmetric matrix of order n with ( i , j ) entry equal to i + j - 2 j - 1 , and let x be a positive real number. Eigenvalues of the Hadamard (or entry wise) power S n ( x ) are considered. In particular for k a positive integer, it is shown that both the Perron root and the trace of S n ( k ) are approximately equal to 4 k 4 k - 1 2 n - 2 n - 1 k .
Construct validity of four exercise stage of change measures in adults

Measuring readiness to exercise, or exercise stage of change (ESOC), is an important first step when counseling adults about exercise. However, minimal construct validity testing of ESOC measures has been reported. With a sample of 95 adults, we estimated the construct validity of four ESOC measures with commonly used response formats (true/false, ladder, 5 choice, interview). Participants completed all four ESOC measures in random order as well as six validation measures: physical activity performed, exercise self-efficacy, decisional balance pros and cons, and behavioral and experiential processes of change. Few participants were in the earliest stage of change. The true/false measure demonstrated the strongest validity. Further studies are needed in diverse samples with more representation across the stages of change. © 2010 Wiley Periodicals, Inc. Res Nurs Health 33:254–264, 2010
Stability of convection in containers of arbitrary shape

When a container of fluid of arbitrary shape is heated from below and the temperature gradient exceeds a critical value ([Rscr ]c2) the conduction solution with no motion becomes unstable and is replaced by convection. The convection may have two forms: one with ‘upflow’ at the centre of the container and one with ‘downflow’ there. Here we study the stability of the two forms of convection. Both forms are here shown to be stable to infinitesimal disturbances. When the viscosity varies with the temperature or the conduction profile is not linear, etc., the steady convection can be driven with finite amplitudes |e| at subcritical values of the temperature contrast ([Rscr ]2 |e*| > 0) but is unstable when the convection is feeble (|e| > |e*|). Hence, when |e| > |e*| and [Rscr ]2 [Rscr ]c2, however, both the ‘upflow’ and the ‘downflow’ can be stable. This contrasts with the corresponding situation which is known to hold when the container is an unbounded layer. In the layer there is only one stable form of convection. The difference between the bounded domain with two forms of convection and the layer with just one stable form is traced to the mathematical property of simplicity of [Rscr ]c2 when viewed as an eigenvalue of the linear stability problem for the conduction solution. It is argued that [Rscr ]c2 is a simple eigenvalue in most domains, but in the layer [Rscr ]c2 can have infinite multiplicity. The explanation of the transition from the bounded domain to the unbounded layer is sought (1) in the chaotic conditions which frequently prevail at the edges of a ‘bounded’ layer and (2) in the fact that in the layer of large horizontal extent, the higher eigenvalues crowd [Rscr ]c2. In the course of the explanation, a new exact solution of the linear Benard problem in a cylinder with a rigid side wall and a stress-free top and bottom is derived.
Pneumonectomy for nonmalignant disease.

BackgroundPneumonectomy for nonmalignant disease is unusual. We wondered about the incidence, predisposing risks, and outcomes of this entity.MethodsWe interrogated the Society of Thoracic Surgeons General Thoracic Surgery Database to compare patients undergoing pneumonectomy for benign or malignant indications between 2006 and 2010.Results309 of 3081 (10%) patients underwent pneumonectomy for nonmalignant conditions. The benign group were younger (56 vs. 62 years), more likely to be on steroid therapy (11.3% vs. 2.7%), and less likely to be current smokers (14.4% vs. 20.1%). Both groups had an equal incidence of comorbidities. Preoperative pulmonary function was decreased in the nonmalignant group: forced expiratory volume in 1 s 61% vs. 74% of predicted; carbon monoxide diffusion in the lung 61% vs. 71% of predicted. The most common nonmalignant etiologies requiring pneumonectomy were lung and pleural infections. The benign group had increased postoperative bleeding, infections, and lung-related complic...
LMC clusters - Age calibration and age distribution revisited

The empirical age relation for star clusters in the Large Magellanic Cloud presented by Elson and Fall (1985) are reexamined using ages based only on main-sequence turnoffs. The present sample includes 57 clusters, 24 of which have color-magnitude diagrams published since 1985. The new calibration is very similar to that found previously, and the scatter in the relation corresponds to uncertainties of about a factor of 2 in age. The age distribution derived from the new calibration does not differ significantly from that derived in earlier work. It is compared with age distributions estimated by other authors for different samples of clusters, and the results are discussed.
Is attention deficit hyperactivity disorder (ADHD) symptom severity associated with tobacco use

Several studies report a strong link between ADHD and tobacco use; however, the nature of this relationship is not entirely clear. We examined the relationship between attention deficit hyperactivity disorder (ADHD) symptoms and tobacco use within a sample of college students. Although tobacco use was the main focus, we also examined alcohol and marijuana use. We examined the association between the number of ADHD symptoms endorsed (severity), and tobacco, alcohol, and marijuana use in a convenience sample of 334 college students in the southeastern United States. Survey data were based on the annual Core Alcohol and Drug Survey for substance use, and the Current Symptom Scale (CSS) for ADHD, conduct disorder (CD), and antisocial personality disorder (ASPD) symptoms. Among ever users of a substance, the number (severity) of current ADHD symptoms, including inattentive and hyperactive symptoms, were significantly associated with the frequency of tobacco and marijuana use in the past month and past year, as well as to the frequency of alcohol use in the past month. The results suggest that the number of ADHD symptoms is proportionally associated with tobacco, alcohol, and marijuana use.
Acoustic characterization of seahorse tank environments in public aquaria: A citizen science project

Abstract Professional aquarists from nine U.S. public aquaria participated in a citizen science project to characterize ambient noise in marine ornamental aquaria containing seahorses ( Hippocampus spp.). Participants collected data on tank design specifications and acoustic recordings from the middle of the water column of each tank surveyed. Ambient noise in aquaria was very variable, ranging in total RMS power from 116.3 to 142.9 dB SPL (re: 1 μPa), with a mean total RMS power of 126.1 ± 0.8 dB. Among tank design specifications: wall material, bottom habitat type, and their interaction had significant effects on total RMS power. Glass tanks were significantly louder than acrylic and concrete tanks, but not fiberglass tanks. Bare bottom tanks were significantly louder than tanks with a plenum or gravel bottom. In the context of literature documenting effects of noise on hearing, acoustic communication, and stress, the exposure to loud ambient noise may be deleterious to aquarium fishes in several ways; thus, system soundproofing techniques are offered. This project demonstrated the utility of citizen science to gather a data set across a large geographic area on a feasible budget, while providing opportunities for professional aquarists to understand the acoustic environment of their systems and appreciate the utility of research to improve animal management.
10 CYTOMEGALOVIRUS (CMV) IN PREGNANT ADOLESCENTS AND THEIR OFFSPRING

A prospective study has been established of CMV among pregnant adolescents and their offspring. Results derived from studies of 53 mothers (mean age 15.6 yrs.) and 54 infants comprise this report. ¶ Thirty-seven of the 53 (81%) were CMV(CF) seropositive when first tested (mean estimated gestational age 23 wks). Twenty-three mothers (43% of total and 62% of seropositives) had one or more positive cultures for CMV and three of their infants (5.5% of total) were congenitally infected with CMV. ¶ The geometric mean (GMT) of maximum CMV titers among virus-positive mothers was 48.5 in contrast to 3.7 among those who were virus-negative (p<0.01). Twelve of 13 mothers with anti CMV titers of 64 or higher were virus-positive and three gave birth to congenitally infected infants. The CMV GMT was 39 in infants born to virus positive mothers compared to a CMV GMT of 4 in babies of virus-negative mothers (p<0.01). All (11) cord blood samples with a titer 64 were obtained from infants born to virus-positive mothers and included those congenitally infected. The determination of maternal and neonatal CMV antibody thus identified a particularly high risk subgroup. ¶ Pregnant adolescents and their offspring may experience frequent CMV infections (exogenous or endogenous in origin). The long term impact of these infections may be a factor in the poor outcome of some teenage pregnancies.
Temperature Circadian Rhythms during the Menstrual Cycle and Sleep Deprivation in Premenstrual Dysphoric Disorder and Normal Comparison Subjects

The aim of this study was to test the hypothesis that the circadian rhythm of core body temperature is altered in premenstrual dysphoric disorder (PMDD) subjects compared to that in normal comparison (NC) subjects and that it is normalized in PMDD subjects after treatment with early night partial sleep deprivation (ESD) or late night partial sleep deprivation (LSD). A total of 23 subjects meeting DSM-IV criteria for PMDD and 18 NC subjects had 24-h core body temperature recordings taken during the following conditions: (1) baseline midfollicular (preovulatory) and (2) late luteal (postovulatory) menstrual cycle phases and after a randomized crossover trial in subsequent luteal phases of (3) ESD, in which subjects slept from 03:00 to 07:00 h, followed by (4) a night of recovery sleep (ESD-R: sleep 22:30 to 06:30 h), and (5) LSD, in which subjects slept from 21:00 to 01:00 h, also followed by (6) a night of recovery sleep (LSD-R: sleep 22:30 to 06:30 h). Temperature amplitudes were significantly decreased in the luteal phase compared to those in the follicular menstrual cycle phase and increased after nights of recovery sleep. Compared to the baseline late luteal phase, during LSD, temperature amplitude increased in PMDD subjects but decreased in NC subjects. During ESD, the temperature acrophase was delayed in PMDD subjects but was advanced in NC subjects; during LSD, the temperature acrophase was advanced in PMDD subjects but was delayed in NC subjects compared to the late luteal baseline. Nocturnal temperature and temperature maxima and mesors tended to be higher in PMDD subjects than in NC subjects; when not reduced during sleep deprivation interventions, these were not associated with therapeutic effects. Alterations in both phase and amplitude of temperature circadian rhythms characterize PMDD subjects as contrasted with NC subjects in response to sleep deprivation. The changes in phase reflected more shifts in temperature acrophase in response to shifts in sleep in PMDD subjects. This realignment of the timing of sleep and temperature in addition to the enhancement of blunted amplitude rhythms during recovery nights of sleep may provide corrective mechanisms that contribute to the therapeutic effects of sleep deprivation.
Real-time comparison of pressure-predicted and Doppler-measured jet velocities distal to left-sided obstructions throughout systole

Abstract We have demonstrated a new real-time technique that allows direct and accurate comparison throughout the entire systolic portion of the cardiac cycle of instantaneous jet velocities predicted by pressure differences across obstructions with those simultaneously measured by Doppler echocardiography. Peak Doppler velocities closely approximate velocities predicted by high-fidelity pressure measurements. Differences may be explained by omission of proximal velocities and the presence of pressure recovery.
Improving construct validity yields better models of systematic inquiry, even with less information

Data-mined models often achieve good predictive power, but sometimes at the cost of interpretability. We investigate here if selecting features to increase a model's construct validity and interpretability also can improve the model's ability to predict the desired constructs. We do this by taking existing models and reducing the feature set to increase construct validity. We then compare the existing and new models on their predictive capabilities within a held-out test set in two ways. First, we analyze the models' overall predictive performance. Second, we determine how much student interaction data is necessary to make accurate predictions. We find that these reduced models with higher construct validity not only achieve better agreement overall, but also achieve better prediction with less data. This work is conducted in the context of developing models to assess students' inquiry skill at designing controlled experiments and testing stated hypotheses within a science inquiry microworld.
Efficiency of propofol versus midazolam and fentanyl sedation at a pediatric teaching hospital: a prospective study.

Background Many pediatric endoscopists are adopting propofol in their practices, with the expectation that propofol will increase their overall efficiency. Objective and Setting To compare the efficiency of propofol versus midazolam and fentanyl by measuring elapsed times between initial intravenous administration and patient discharge at a pediatric teaching hospital. Design Endoscopy times were prospectively collected for consecutive patients who were undergoing either anesthesiologist-administered propofol or endoscopist-administered midazolam and fentanyl. The effect of the type of sedation on these times was assessed by using multiple linear regression by adjusting for other candidate predictors, including concomitant use of other sedatives, endotracheal intubation by anesthesiologists, and the presence of fellow trainees. Main Outcome Measurements Time to onset of sedation (time sedation started to scope in), procedure time (endoscope in to endoscope out), discharge time (endoscope out to hospital discharge), and total time (sedation started to hospital discharge). Results The times for 134 children (mean age 12 ± 5 years) to receive propofol sedation were compared with those of 195 children (13 ± 5 years) who received midazolam and fentanyl. Midazolam and fentanyl cases disproportionately included EGDs ( P P P P Conclusions Anesthesiologist-administered propofol sedation in a pediatric teaching endoscopy unit may not lead to faster hospital times when compared with endoscopist-administered midazolam and fentanyl. These results are not explained by controlling for patient characteristics, the presence of a trainee, the sedative doses, or endotracheal intubation for airway management.
Quantifying the amount of impact ejecta at the MER landing sites and potential paleolakes in the southern Martian highlands

[1] Applying previous equations for estimating ejecta thickness to Mars, tens of meters of ballistically-emplaced impact ejecta might be expected over the heavily-cratered southern Martian hemisphere. The calculated thickness of ejecta material, even accounting for large uncertainties in methods of estimation, is not enough to fully explain observed depth discrepancies in Gusev Crater or in other potential Martian paleolakes. Ejecta contributed to the Spirit landing site in Gusev Crater is largely derived from local craters while distal ejecta from large, faraway craters dominates the contribution to the Opportunity landing site in Meridiani Planum. However, emplacement of this type of ejecta probably predates the present surfaces. Thira crater may have excavated impact-melt products created by Gusev, samples of which would provide a unique insight into the composition of the bulk Martian crust. Though ballistically-emplaced crater ejecta contribute a relatively small amount of material to any given site, this type of material provides important lithologic diversity.
Cosmic-Ray Electrons and Positrons from 1 to 100 GeV: Measurements with HEAT and Their Interpretation

Measurements of the energy spectra of negative electrons and positrons have been performed with the High-Energy Antimatter Telescope (HEAT) in two balloon flights—1994 May from Fort Sumner, NM, and 1995 August from Lynn Lake, Manitoba. We present the combined data set from these two flights, covering the energy range 1-100 GeV. We compare our data with results from other groups and discuss the data in the context of diffusive propagation models. There is some evidence that primary electrons above 10 GeV and cosmic-ray nuclei exhibit the same energy spectrum at the source, but that the source spectrum becomes harder at lower energy. Within the experimental uncertainties, the intensity of positrons is consistent with a purely secondary origin, due to nuclear interactions in interstellar space.
Review: Acetaminophen reduces acute migraine pain in adults

Source Citation Derry S, Moore RA, McQuay HJ. Paracetamol (acetaminophen) with or without an antiemetic for acute migraine headaches in adults. Cochrane Database Syst Rev. 2010;(11):CD008040. 21069700
Standing stock and estimated production rates of phytoplankton and zooplankton in Narragansett Bay, Rhode Island

Seasonal changes in phytoplankton biomass and production, total zooplankton biomass, and biomass and potential production rates of the two dominant copepods, Acartia hudsonica (formerly called Acartia clausi) and Acartia tonsa are described for several stations in Narragansett Bay, R.I. Plankton in the bay behaved as a single population with simultaneous changes occurring at the upper bay (Station 5) and the lower bay (Station 1). Phytoplankton biomass was higher in the upper bay ( $$\bar x$$ =16.95 mg chl a·m−3) than in the lower bay ( $$\bar x$$ =6.37 mg chl a·m−3) and these 0269 0101 V differences in biomass were reflected in the phytoplankton production rates. The zooplankton, which was dominated by A. hudsonica in the spring and early summer and A. tonsa during summer and fall, showed no such consistent differences between the stations. Mean A. hudsonica biomass (St 1, $$\bar x$$ ;=82.7 mg dry wt·m−3; St 5, _ $$\bar x$$ ;=95.2 mg dry wt·m−3) exceeded that of A. tonsa (St 1, $$\bar x$$ ;=56.7 mg dry wt·m−3; St 5, $$\bar x$$ ;=60.0 mg dry wt·m−3). Potential production rates of the two Acartia 0269 0101 V spp. were strongly temperature dependent. Despite the higher biomass levels of A. hudsonica, low temperatures resulted in lower potential production rates ( $$\bar x$$ ; St 1=7.25 mg C·m−3 day−1; $$\bar x$$ ; St 5=10.77mg C·m−3 day−1) and biomass doubling times of up to 9.6 days. Potential production rates of A. tonsa at summer temperatures were high ( $$\bar x$$ ; St 1=19.0 mg C·m−3 day−1; $$\bar x$$ ; St 5=22.9 mg C·m−3 day−1) and biomass doubling times were generally less than one day.
Investigation of the relation between self-reported food consumption and household chemical exposures with urinary levels of selected nonpersistent pesticides.

Concerns about pesticide exposure through food consumption have increased during the past several years. The main objective of our study was to determine whether we could use data from the Third National Health and Nutrition Examination Survey (NHANES III) to detect a relation between self-reported food consumption — particularly consumption of fruits, vegetables, and bread products — and urinary levels of pesticides or their metabolites in a population of 978 adults living in the US. A secondary objective was to investigate whether these urine levels differed for people who reported exposure to selected common household chemicals including bug or insect spray, weed killer, and mothballs or crystals. We used monthly food frequency data from the NHANES III, 1988–1994. Urinary pesticide/metabolite levels and information about chemical exposures were taken from the Priority Toxicant Reference Range Study (a component of the NHANES III). Six pesticides or their metabolites were detected in at least 50% of the sample, three of which — 1-naphthol (86.4%), pentachlorophenol (62.5%), and 3,5,6-trichloro-2-pyridinol (82.0%) — were possibly related to food consumption. We were unable to detect a relation between self-reported food consumption and their urinary levels. This may be due more to the limitations of the datasets than to a lack of a relation between food consumption and urine pesticide/metabolite levels. We did find that people who reported recently using selected common chemicals had higher geometric mean urine pesticide/metabolite levels than did people who reported not recently using these chemicals.
A scintillation counter array for detection of high energy neutrons

Abstract An array of 32 liquid scintillation counters used to detect neutrons in the energy range 20 to 340 MeV is described. Each unit consisted of a cylinder 45 cm long and 7 cm diameter, with the axis of the cylinder parallel to the incident neutron direction. The array was calibrated in the above energy range by use of neutron-proton elastic scattering. The average efficiency was 0.45. Some secondary properties of the array have been studied and are described.
Machine-part family formation with the adaptive resonance theory paradigm

The ARTI neural network paradigm employs a heuristic where new vectors arc compared with group representative vectors for classification. ARTI is adapted for the cell formation problem by reorderin...
Stomach tumors and gastric surgery.

ABSTRACT Malignant and benign tumors of the stomach must be resected. Some can be removed endoscopically, but larger lesions must be removed via traditional surgical methods. This article provides an overview of malignant and benign stomach tumors and outlines the determination of diagnosis and the recommended treatment. It describes different types of gastric surgery and the RN first assistant's role in these procedures. A case study of a rare type of benign stomach tumor also is presented. AORN J 69 (April 1999) 824–832.
Closed-loop modeling of power and temperature profiles of FPGAs

In recent times, the contribution of leakage power to the total power consumption of a chip has been increasing at an alarming rate. Leakage power is expected to exceed dynamic power in newer process technologies. Since leakage exhibits an exponential increase with temperature, it is possible that the high leakage of an IC causes a temperature increase, which in turn causes an increase in leakage, and so on, until the IC fails due to overheating. At the very least, this may cause the temperature and power consumption of the IC to be poorly estimated by traditional thermal or power modeling techniques. We developed a framework to model this situation in an FPGA context. Our CAD framework accurately models the total power consumption of the design at a given temperature, finds the thermal profile of the IC under this power consumption, and then uses this new thermal information to update the power consumption. This is iterated until the temperature of the IC converges, or until the temperatures on the die exceed a safe value. The iterations are very fast, due to the use of accurate and compact mathematical macromodels for leakage and temperature computation in the inner loop. We have exhaustively verified the fidelity of all our leakage macromodels. They estimate the leakage, at any temperature, to within 3% of the values generated by SPICE, while providing greater than four orders of magnitude speedup over explicit SPICE runs. Our experiments show that this model helps avoid an incorrect estimation of chip temperature and total power consumption, and also helps detect the increase in device temperature beyond a safe value. The average (maximum) error of our temperature estimates has been found to be within 1% (2.5%) compared to a full-chip 3D temperature modeling tool.
Long-Term Patient Survival: Strategies to Improve Overall Health

The use of potent immunosuppressant therapy has led to an increase in number of patients with successful long-term kidney transplants. These individuals come to kidney transplantation with varying levels of comorbidity associated with end-stage renal disease and are susceptible to immunologic and nonimmunologic comorbidities that arise late after transplantation, including cardiovascular disease, infection, malignancy, and bone disease, which negatively impact on patient and graft survival. In addition, nonadherence to immunosuppressant regimens increases with time after transplantation, which further augments the risk for late-term graft failure and mortality. Consistent and frequent follow-up of kidney transplant recipients beyond the first year permits early diagnosis and successful treatment of many posttransplantation comorbidities. Implementation of preventive practices and aggressive management of risk factors throughout the life of the transplant improves overall health and long-term outcomes. Establishment and maintenance of close relationships among transplant centers, physicians, patients, and their families improves patient adherence to medications and reduces the risk for morbidity and mortality.
Lie theoretic aspects of the Riccati equation

Various features of the application of Lie theory to matrix Riccati equations, of basic importance in control and system theories, are discussed. Particular consideration is given to centralizer foliation, the Cartan decomposition, matrix Riccati equations as Lie systems on Grassmanians, local analysis near a zero point of a vector field, linearization in homogeneous space, the tangent bundle in terms of partitioned matrices, and stability properties of fixed points of Riccati vector fields.
DIFFERENTIAL REGULATION BY GLUCOCORTICOIDS OF PROOPIOMELANOCORTIN mRNA LEVELS IN THE ANTERIOR AND INTERMEDIATE LOBES OF THE RAT PITUITARY

Glucocorticoids negatively regulate de novo synthesis of proopiomelanocortin (POMC) and the steady state POMC mRNA levels in the rat pituitary anterior lobe. The POMC system of the intermediate lobe is far less sensitive to alterations in circulating glucocorticoid levels. Possible mechanisms for this differential regulation of POMC gene expression in the two tissues are discussed.
Reshaping Graduate Preparation in Educational Research Methods: One School’s Experience

Questions about the proper preparation in research methodologies of doctoral students in education are again on the front burner, fed by deepening skepticism about the value of educational research as well as a revived “paradigms war” and broad criticism of the state of graduate education. Faculty struggle to decide whether or not to require all doctoral students to study both quantitative and qualitative research methods, regardless of students’ diverse talents, interests, and career aspirations. Should students be required to “appreciate” both methodologies or to be able to use both? How should research methodologies be taught, and what proportion of doctoral study should they occupy? This article describes the processes and circumstances in which the faculty in a school of education at a research university grappled with these questions and, in time, significantly redesigned its doctoral curriculum. Although the faculty’s experience is necessarily particular, their engagement in practical reasoning, lo...
Nonparametric Bayesian estimation of a bivariate density with interval censored data

Mixture of Polya trees nonparametric estimation of a bivariate density is presented for interval censored data. Real and simulated data are analyzed and compared with nonparametric maximum likelihood (NPMLE) and Bayesian G-spline estimates. An advantage of the mixture of Polya trees approach over the NPMLE is the relative ease with which continuous bivariate density and hazard plots are obtained.
Concept Design Center Pre-work Overview

The Aerospace Corporation’s Concept Design Center (CDC) is nearing the completion of its 200 th Space Segment Team (SST) study. While a number of papers have been written on SST activities over the years, the process by which a study is conducted has evolved considerably in that time period. This paper will delve into an often under-appreciated portion of the study work: the pre-study analysis necessary to scope the tradespace appropriately. Often times, several months are required to pare a complex, large tradespace down to about 10 to 12 interesting trades that both bound the range of requirements acceptable to stakeholders and fit within the capabilities of current technologies, which may cause a re-evaluation of requirements. At the same time, an effort is made to identify the optimal solutions within that tradespace as the basis for more detailed design work. Typically, the study leads (system engineering experts) will bring in some of the subsystem engineers (communications, astrodynamics, power, etc.) for periodic meetings prior to the concurrent portion of the study to select orbits, constellation size, payload parameters, concept of operations, and future technology limitations, amongst other variables that will drive the design choices in the study. Significant iteration is often required in this initial design process, as infeasible and dominated point solutions are considered, but then discarded. This pre-work is critical in ensuring that the concurrent portion of the study flows smoothly, and is not halted while small groups of people try to solve a problem while the rest of the team sits and waits, thus wasting time and money. Of course, the team is not always successful in this regard, but this deliberate process minimizes such disruptions. This paper will use the CATS MEO (Communication And Telemetry, tracking, and command System in Medium Earth Orbit) CDC SST studies as an example of this process from inception up to the concurrent portion of the study.
Fast Fission Assisted Ignition of Thermonuclear Microexplosions

It is shown that the requirements for fast ignition of thermonuclear microexplosions can be substantially relaxed if the deuterium-tritium (DT) hot spot is placed inside a shell of U-238 (Th-232). An intense laser - or particle beam-projected into the shell leads to a large temperature gradient between the hot DT and the cold U-238 (Th-232), driving thermomagnetic currents by the Nernst effect, with magnetic fields large enough to entrap within the hot spot the α-particles of the DT fusion reaction. The fast fission reactions in the U-238 (Th-232) shell implode about ½ of the shell onto the DT, increasing its density and reaction rate. With the magnetic field generated by the Nernst effect, there is no need to connect the target to a large current carrying transmission line, as it is required for magnetized target fusion, solving the so-called "stand off" problem for thermonuclear microexplosions.
Creating corporate success: Strategic choices

The Planning Forum's Annual Conference in Washington, D.C. posted another attendance record. Some 1300 senior executives exchanged war stories, business theories, and points of view with each other while attending three days of presentations by major company CEOs, consultants to leading corporations, noted academics, and practitioners of strategic management.
Chemical systems for delivery of antiepileptic drugs to the central nervous system

Abstract The chemical delivery system (CDS) approach, a recently developed procedure conceived to enhance the specific central nervous system (CNS) uptake of drugs, has been applied to several antiepileptic agents. CDSs based on dihydropyridine∌pyridinium salt type redox targetors, reversibly linked to the drug, were designed, synthesized and tested for some traditional (phenytoin, valproate) and potential (stiripentol) antiepileptic drugs, as well as some compounds (GABA, adenosine) with important roles in epileptogenesis. Physicochemical, in vitro stability, in vivo tissue distribution, activity and toxicity studies were performed for the new derivatives. The results of these investigations indicated that selected CDSs possessed properties required for delivering the drugs to the CNS. In vivo experiments indicated improved brain uptake and enhanced pharmacologie activity in some of the examined cases. On the other hand, no toxic side effects were registered during the studies. Properly developed CDSs could enhance the therapeutic indexes of the anticonvulsant drugs.
The palliation of osseous metastasis with 32P or 89Sr compared with external beam and hemibody irradiation: a historical perspective.

AbstractRadiation is an effective modality for palliation of osseous metastases. Inpatients with a limited number of lesions, local external beam irradiation is the most expedient method of delivering radiation therapy. Complete or partial relief of pain will occur in 80-90% of patients. When metastases are widespread or when new sites continue to appear, localized external irradiation becomes logistically difficult. In such cases, hemibody irradiation has been effective with an overall response rate of 85%. However, nausea, vomiting, diarrhea, and bone marrow and pulmonary toxicity may complicate therapy. In these cases, an effective alternative is systemic phosphorus-32 (32P) or strontium-89 (89Sr). Relief of pain in the range of 60-90% has been reported. Toxicity of32P is largely that of bone marrow suppression, while 89Sr appears to be relatively marrow-sparing. In this review, we consider systemic 32P or 89Sr as viable options to external beam or hemibody irradiation in the presence of numerous bone ...
A Perturbed pKa at the Binding Site of the Nicotinic Acetylcholine Receptor: Implications for Nicotine Binding

A series of tethered quaternary ammonium derivatives of Tyr have been incorporated into the binding site of the nicotinic acetylcholine receptor (nAChR) using the in vivo nonsense suppression method, producing constitutively active (self-gating) receptors. We have incorporated primary, secondary, and tertiary amine tethered agonists to give receptors whose constitutive activity can be modulated by pH. Lowering the pH protonates the tethered amine, giving it a positive charge and allowing it to reversibly activate the receptor. Tertiary and secondary tethered amines, TyrO3T and TyrO3S, have been successfully incorporated at α149 in the nAChR. Constitutive currents at pH 5.5 are 6 times those at pH 9.0. The pK_a of TyrO3T in the binding site appears to be 6 or lower, differing substantially from its pK_a in solution (∼9.3). This local pK_a perturbation has substantial implications for pharmacological research on the nAChR: of the tertiary agonists considered, noracetylcholine experiences this pK_a perturbation, while nicotine does not.
EXAFS Study of the Initial Interface Region Formed by Thin Zirconium and Titanium Films on Silicon(111)

While titanium has long been of interest for use in creating low resistivity metal contacts on silicon, the commonly resulting epitaxial silicide (TiSi2) is often of C49 phase and is, unfortunately, metastable - transforming to the stable C54 phase at higher temperatures. Zirconium, however, only exhibits a C49 phase disilicide and, being in the same periodic group, is chemically similar to Ti, affording the possibility of alloying small quantities of Zr with Ti in order to stabilize the epitaxial C49 structure. Both Ti and Zr have been reported to show a strongly disordered interface region at low temperatures, but little quantitative structural work has been performed on the Zr:Si system. To this end, an initial structural study of the Zr on Si (111) system has been undertaken. Thin films (100A) of Zr were deposited in UHV conditions onto atomically clean Si(111) wafers and annealed in situ at fine temperature intervals between 300 and 425°C, over which range Auger spectroscopy indicated Si diffusion to the surface. A comparison will be made with the Ti:Si system for samples of 100A Ti prepared under the same conditions.
The Strategic Role of Human Collaboration in Supply Chain Management

Supply chain performance is often equated with acquiring the best technology or process. However, current studies suggest that supply chain performance also requires human collaboration. To change conventional thinking, this paper proposes a holistic approach to supply chain management (SCM), clarifies the forces that facilitate human collaboration, and identifies the steps management can take to create a more collaborative network.
The Immunohistochemical Characteristics of the Basosquamous Cell Carcinoma

BACKGROUND The basosquamous cell carcinoma (BSCC) is a poorly defined and often misunderstood cutaneous malignancy. OBJECTIVE The purpose of this study was to compare, using immunohistochemical techniques, the BSCC, basal cell carcinoma (BCC), and squamous cell carcinoma (SCO). METHODS BSCC occurring at Pennsylvania State University over the past 10 years were identified. Choosing seven BCC, and nine SCC as controls, all specimens were stained for keratin, lack of apoptosis, glycoproteins, and altered gene products using the avidin/biotin and strep-avidin immunoperoxidase techniques. Each malignancy was then graded for the percentage of cells stained with each marker. RESULTS Of the markers studied, all stained to varying degrees the malignant aspects of the specimens. There were similar patterns between tumors, with the BSCC showing a transition zone between typical BCC and SCC. This was most striking for Ber-EP4, where over two-thirds of the BCC stained, none of the SCC, and half of the BSCC showed reactivity. CONCLUSION BSCC has staining patterns similar to both the BCC and SCC. The presence of a transition zone does not support the concept that all BSCC are collision tumors, but rather a differentiation of one tumor into another. We confirm earlier reports that Ber-EP4 could be used to distinguish between classic BCC and SCC. AE1/AE3, bcl-2. TGF-alpha, and p53 were not helpful in separating the tumors.
Overview of DARPA MTO GPU program

This paper reviews the DARPA MTO STAP-BOY program for both Phase I and II. The STAP-BOY program conducts fast covariance factorization and tuning techniques for space-time adaptive process (STAP) Algorithm Implementation on Graphics Processor unit (GPU) Architectures for Embedded Systems. Emerging capabilities in stream and multi-core computation, along with high speed memory bandwidths in commercial GPU architectures, are enabling breakthrough low-cost and low-power teraflop computing solutions to DoD-embedded computing challenges. Under the DARPA MTO STAP-BOY program, SAIC and Duke University, in cooperation with commercial graphics processor companies, have been mapping complex signal processing algorithms to GPU architectures. Algorithms undergoing implementation include STAP applications for radar adaptive beamforming and spin-image surface matching applications for object recognition in 3-D range-image data.
A modest proposal in response to the chronic underfunding of microcomputer facilities

This paper is a discussion of problems faced by those who are seeking to more thoroughly integrate information technology into the instructional process. It includes: An analysis of the conflict within universities between organizations responsible for the provision of instructional facilities and those responsible for the promotion of information technology. The impact upon the development of microcomputerization is discussed.A taxonomy of computerized instructional facilities is compared with reality. The taxonomy differentiates instructional facilities and instructional facilities from microcomputer clusters. Problems associated with hybridizing these functions is discussed.Funding practices at Northwestern University are examined in light of their impact upon the growth of instructional facilities. These practices are thought to be not unusual at research organizations. An attempt is made to relate these practices to organizational form.Alternative funding strategies which assume a functional differentiation among computational facilities are discussed.Results from a brief E-mail survey of 38 schools on charge back practices are presented. Information is sketchy, but raw counts and anecdotal responses indicate that problems discussed in this paper are a general and growing concern. Diversity of solutions indicate that America's universities are groping for a coherent approach, but that no consensus has emerged.
Non-cooperative equilibrium with price discriminating firms☆

Abstract There exists a unique, non-cooperative equilibrium in output levels for a group of firms which sell differentiated products and are able to practice first degree price discrimination. The equilibrium does not maximize joint profits.
Bovine Somatotropin: Biotechnology Product and Social Issue in the United States Dairy Industry

Abstract Cows produce more milk when injected with bST. Advances in biotechnology have lowered manufacturing costs for the substance to the point where firms are endeavoring to develop usable products, obtain regulatory approval, and market the technology to dairy farms. This paper examines bST as a case study in the advent of a biotechnology-based innovation, one of the first to enter the market. Bovine somatotropin has been controversial because of its perceived lack of safety, impact on farm structure, potential to shift the regional location of dairy production, and implications for government spending on milk price supports. The evolution of this technology is reviewed in the context of the various claims, reactions, and projections of researchers, economic analysts, farm groups, and populist critics. An assessment is made of how the rapid diffusion and widespread use of bST will affect farmers, rural communities, and the dairy industry.
“Faces” and Complexities of Continuing Higher Education Units: A Postmodern Approach

Abstract This study examines the dynamics of continuing higher education units within the sociopolitical context of higher education institutions. A qualitative approach to data collection and analysis was the study's design, while the theoretical frame was a postmodern, symbolic, theoretical approach to organizational studies. Results show that continuing education is a ubiquitous feature, found in every sphere of postsecondary education. However, various kinds of organizational configurations prevail. In addition, drawing on social and cultural anthropology as espoused by Bolman and Deal's four-frame model to “make sense of organization” at least six symbolic models and three organizational frameworks were construed as ways that leaders interpret their unit's organizational structure within their parent institution. The ability to visualize different models and organizational structures of continuing higher education divisions in today's educational environment is important to understand their division-...
The sharing architecture: sub-core configurability for IaaS clouds

Businesses and Academics are increasingly turning to Infrastructure as a Service (IaaS) Clouds such as Amazon's Elastic Compute Cloud (EC2) to fulfill their computing needs. Unfortunately, current IaaS systems provide a severely restricted pallet of rentable computing options which do not optimally fit the workloads that they are executing. We address this challenge by proposing and evaluating a manycore architecture, called the Sharing Architecture, specifically optimized for IaaS systems by being reconfigurable on a sub-core basis. The Sharing Architecture enables better matching of workload to micro-architecture resources by replacing static cores with Virtual Cores which can be dynamically reconfigured to have different numbers of ALUs and amount of Cache. This reconfigurability enables many of the same benefits of heterogeneous multicores, but in a homogeneous fabric, and enables the reuse and resale of resources on a per ALU or per KB of cache basis. The Sharing Architecture leverages Distributed ILP techniques, but is designed in a way to be independent of recompilation. In addition, we introduce an economic model which is enabled by the Sharing Architecture and show how different users who have varying needs can be better served by such a flexible architecture. We evaluate the Sharing Architecture across a benchmark suite of Apache, SPECint, and parts of PARSEC, and find that it can achieve up to a 5x more economically efficient market when compared to static architecture multicores. We implemented the Sharing Architecture in Verilog and present area overhead results.
Genomic organization of two families of highly repeated nuclear DNA sequences of maize selected for autonomous replicating activity in yeast.

Maize nuclear DNA sequences capable of promoting the autonomous replication of plasmids in yeast were isolated by ligating Eco RI-digested fragments into yeast vectors unable to replicate autonomously. Three such autonomously replicating sequences (ARS), representing two families of highly repeated sequences within the maize genome, were isolated and characterized. Each repetitive family shows hybridization patterns on a Southern blot characteristic of a dispersed sequence. Unlike most repetitive sequences in maize, both ARS families have a constant copy number and characteristic genomic hybridization pattern in the inbred lines examined. Larger genome clones with sequence homology to the ARS-containing elements were selected from a lambda library of maize genomic DNA. There was typically only one copy of an ARS-homologous sequence on each 12–15 kb genomic fragment.