cssi/SciSciGPT-SciSciNet huggingface dataset:
Physical Design Variation in Relative Timed Asynchronous Circuits

Variations in integrated circuits stem from multiple sources. This paper studies variations in placement and delay that occur when using commercial EDA in a relatively unsupported fashion – to implement large unclocked circuits. A tool suite is built to study placed and routed designs. Significant variations in physical placement is shown, leading to degradation in performance, power efficiency, and robustness. An experimental method of mitigating timing and placement variation using relative place directives is applied, resulting in circuits that are 7% faster and 4% lower power.
An Unsung Hero

Over the past fifteen years, renal transplantation has become the most acceptable treatment of end-stage renal disease. Because transplantation returns the patient to a normal physiological state by restoring normal renal function, it is more acceptable than hemodialysis or peritoneal dialysis which, although prolonging survival in these patients, cannot adequately compensate for all of the complications of the uremic state.
Conversion of Solar Energy Using Tandem Photovoltaic Cells Made from Multi-Element Semiconductors

In preceding chapters, the discussion has focused on solar cells in which the photovoltaically active semiconductor is the element silicon or a binary semiconductor like GaAs, Cu2S, InP, etc. This chapter is concerned with solar cells in which the photovoltaically active semiconductor is based on three or more elements. Specifically, three groups of such semiconductors will be considered, namely, (1) semiconductors which are alloys of binary semiconductors (e.g. AlxGa(1-x)As or GaxIn(1-x)PyAs(1-y)); (2) “true” ternary semiconductors (e.g. CuInS2, CuInSe2) and (3) alloys of these true ternaries (e.g. CuInS2Se2(1-z), z < 1.0).
Mass Casualty Shooting Venues, Types of Firearms, and Age of Perpetrators in the United States, 1982-2018.

Objectives. To evaluate the association between mass casualty shooting venues, types of firearms, and the age of perpetrators in the United States.Methods. We analyzed data on mass casualty (≥ 3 fa...
Rituximab maintenance for mantle cell lymphoma: A meta-analysis.

e19557Background: The role of rituximab maintenance (RM) in mantle cell lymphoma (MCL) is unclear. Currently, rituximab is not an FDA approved therapy for this indication. We conducted a systematic...
Accessible Personal Ultrasound Training Simulator

Objectives Ultrasound simulators are increasingly used for teaching and training purposes, but development has been limited by the need for dedicated and often expensive hardware. The objective of this study was to develop and deploy an accessible and very low-cost personal ultrasound training simulator and obtain trainee feedback. Methods An ultrasound simulator software program that uses a smartphone as a "mock-probe" and a laptop computer as a "mock ultrasound machine" was created. Spatial positional data is acquired from the smartphone's inbuilt accelerometer and gyroscope and transmitted to the laptop computer for processing and display of simulated ultrasound images in real time by the software program. After obtaining institutional review board approval and informed consent, all first-year radiology residents at our institution were provided access to the simulator program during the "bootcamp" introductory conference series, and a written survey was conducted to obtain feedback. Results A personal ultrasound training simulator software program (Persimus) that reliably performs motion sensing along 2 axes and displays simulated ultrasound images was developed. Nine of 12 (75%) first-year residents at our institution participated in the written survey. Residents' scored values were 8.44 ± 1.33 and 8.44 ± 1.33 (mean + standard deviation) for perceived utility and overall impression and satisfaction, respectively, of the simulator on the Likert scale (1-10, with 10 being the highest score). Conclusion Personal ultrasound simulators are technically feasible. These are well received by first-year radiology residents and perceived as useful to their education.
Agent-Based Microgrid Power Management and Microgrid-based Resilient Distribution System

This paper presents a distributed agent-based microgrid (MG) power management strategy. MG power management is based on agents’ negotiation and the Nash bargaining solution (NBS) to reach a Pareto optimal solution. Further, a MG-based resilient distribution system consisting of regional energy networks, distribution feeders, and inter-regional MGs is introduced.
The Relation Between Early Adolescent Physical Activity and Internalizing Problems: Variations in Exercise Motivations as a Critical Moderator:

Inconsistencies exist regarding the relation between physical activity (PA) and internalizing symptomology in early adolescence, and there is need for investigation of potential moderators that may account for these discrepancies. The current study utilized a Self-Determination Theory Framework to investigate the main effects of five key motivations to exercise and their moderating effects between PA and internalizing problems in an underserved sample of adolescents (n = 167; mean age = 12.19 years; 73% African American). Analyses showed that intrinsic motivations were negatively related to internalizing problems and extrinsic motivations were positively related. PA was only protective against internalizing problems when intrinsic motivations were high and had iatrogenic effects when these were low. Exploratory analyses further delineated the unique effects of motivational orientations. Clinical implications and future research directions are discussed.
3D Muscle Architecture of the Pectoral Muscles of European Starling ( Sturnus vulgaris ).

Avian flight is achieved through a number of modifications to the body, including the pectoral girdle, yet little is known about the architecture of the pectoral musculature. Muscle architecture is a critical variable in determining the biomechanical function of the vertebrate musculoskeletal system; however, accurate three-dimensional (3D) understanding of muscle architecture has been historically difficult to acquire. Here, we present a musculoskeletal model of a European starling (Sturnus vulgaris) pectoral girdle generated from iodine contrast-enhanced micro-computed-tomography (CT) data and 3D fiber tracking analysis. We used a template-based fiber-tracking algorithm to reconstruct muscle fibers in 3D based on grayscale differences in CT images, which allowed us to estimate fascicle lengths, pennation angles, muscle volumes, and physiological cross-sectional area. Our modeled muscles were qualitatively accurate; however, quantitative muscle architecture data differed between digital and traditional gross-dissection methods reflecting the complex organization of the tissue and differing natures of data collection. We found that model quality is affected by the resolution of CT image data and the fiber-tracking program's input parameters. Nonetheless, digital fiber tracking offers numerous advantages over gross-dissection methods, most importantly, the ability to visualize and quantify entire muscles in three-dimensions, yielding a much more accurate estimation of whole muscle architecture.
Temperature impacts on dengue emergence in the United States: Investigating the role of seasonality and climate change

Tropical mosquito-borne viruses have been expanding into more temperate regions in recent decades. This is partly due to the coupled effects of temperature on mosquito life history traits and viral infection dynamics and warming surface temperatures, resulting in more suitable conditions for vectors and virus transmission. In this study, we use a deterministic ordinary differential equations model to investigate how seasonal and diurnal temperature fluctuations affect the potential for dengue transmission in six U.S. cities. We specifically consider temperature-dependent mosquito larval development, adult mosquito mortality, and the extrinsic incubation period of the virus. We show that the ability of introductions to lead to outbreaks depends upon the relationship between a city's temperature profile and the time of year at which the initial case is introduced. We also investigate how the potential for outbreaks changes with predicted future increases in mean temperatures due to climate change. We find that climate change will likely lead to increases in suitability for dengue transmission and will increase the periods of the year in which introductions may lead to outbreaks, particularly in cities that typically have mild winters and warm summers, such as New Orleans, Louisiana, and El Paso, Texas. We discuss our results in the context of temperature heterogeneity within and across cities and how these differences may impact the potential for dengue emergence given present day and predicted future temperatures.
Fracture of an anisotropic rare-earth-containing magnesium alloy (ZEK100) at different stress states and strain rates: Experiments and modeling

Abstract Fracture of an anisotropic rare-earth-containing magnesium alloy (ZEK100) sheet is investigated at different stress states and strain rates. A variety of sample geometries, loading conditions, and loading orientations are used to achieve different stress triaxiality and deformation mechanisms. Digital image correlation (DIC) technique is used to measure the surface strains up to fracture for all the specimens. We show that ZEK100 exhibits larger strain at fracture across the gage section of the test specimens aligned with the transverse direction (TD) than specimens aligned with the rolling direction (RD); however, the opposite is shown for the local strain measurements at fracture. With an increase in the strain rate, the strains at fracture decrease for all loading paths. A crystal plasticity finite element model is used to simulate the local stress state and deformation mechanisms for each loading condition. ZEK100 exhibits an anisotropic fracture behavior that is a function of the stress triaxiality and Lode parameter. We show that extension twinning also plays an important role in the fracture response of ZEK100. Overall, the local effective strain at fracture is lower for the specimens that exhibit the largest volume fraction of extension twinning. A novel anisotropic extension to the Hosford-Coulomb (HC) fracture model is then developed to account for the effect of extension twinning on the anisotropic fracture response of ZEK100.
Data Mining in Global Higher Education: Opportunities and Challenges for Learning

© 2020, IGI Global. All Rights reserved. Historically, educators in higher education have searched for reliable means and methods to increase student learning. Many techniques and strategies have been used and even some have taken the form of laws to incorporate certain approaches to learning. However, there has not been one method proved effective in all situations for all students. One of the biggest challenges that global educational institutions face is the explosive growth of educational data and how to use this data to improve the quality of instructional and managerial decisions. Global higher education leaders embraced data-driven practices as an opportunity to improve efficiency, objectivity, transparency, and innovation. As a result, global higher education institutions are producing a large amount of student related data every year. Technology has given educators in higher education access to methods for assessing learning and engagement. Educational data mining is a relatively new process in global higher education that provides a tool to analyze this data and extract valuable information.
Examination of models for determining saturated hydraulic conductivity by the constant head well permeameter method

Abstract In the constant head well permeameter method the saturated hydraulic conductivity (Ks) of the vadose zone is determined by the equation Q = A × Ks, where Q is the steady state rate of water flow into the soil from a cylindrical hole of known diameter under a constant depth of water, and A is a factor that must be calculated by a model. The Glover model for determining factor A was developed approximately 70 years ago by considering the hydrostatic pressure and gravity in a saturated zone around the hole. This model does not depend on soil texture or structure. Newer models, on the other hand, consider both saturated and unsaturated flow of water, and include both Ks and the capillary factor α (sorptive number) that must be determined independently or be estimated based on soil texture and structure. The main objective here is to compare these models and demonstrate that they yield similar results for coarse-textured soils (relatively large α), but those that consider both saturated and unsaturated flow yield unrealistic results for medium- to fine-textured soils with relatively small α values. The soil water profile around a cylindrical hole under a constant depth of water is initially composed of a bulb-shaped saturation zone (pressure head h > 0), saturation front (h = 0), transmission and wetting zones (h
Oxygen supply capacity breathes new life into critical oxygen partial pressure (Pcrit).

The critical oxygen partial pressure (Pcrit), typically defined as that below which an animal9s metabolic rate (MR) is unsustainable, is widely interpreted as a measure of hypoxia tolerance. Here, Pcrit is defined as the PO2 at which physiological oxygen supply (α0) reaches its maximum capacity (α; µmol O2 g−1h−1kPa−1). The α is a species- and temperature-specific constant describing the oxygen dependency of the maximum metabolic rate (MMR= PO2*α) or, equivalently, the metabolic rate-dependence of Pcrit (Pcrit=MR/α). We describe the α-method, in which the MR is monitored as oxygen declines and, for each measurement period, is divided by the corresponding PO2 to provide the concurrent oxygen supply (α0=MR/PO2). The highest α0 value (or, more conservatively, the mean of the three highest values) is designated as α. The same value of α is reached at Pcrit for any MR regardless of previous or subsequent metabolic activity. The metabolic rate needn9t be constant (regulated), standardized, nor exhibit a clear-breakpoint at Pcrit for accurate determination of α. The α-method has several advantages over Pcrit determination and non-linear analyses, including: 1) less ambiguity and greater accuracy, 2) fewer constraints in respirometry methodology and analysis, and 3) greater predictive power and ecological and physiological insight. Across the species evaluated here, α values are correlated with MR, but not Pcrit. Rather than an index of hypoxia tolerance, Pcrit is a reflection of α, which evolves to support maximum energy demands and aerobic scope at the prevailing temperature and oxygen level.
C1-2 rotatory subluxation as a presenting sign in juvenile rheumatoid arthritis.

Case report. Juvenile rheumatoid arthritis (JRA) typically presents with fever, rash, anterior uveitis, and/or joint pain. We present three cases with initial torticollis due to rotatory subluxation of C1–C2 as an initial sign of JRA. Three girls, ages 5–9, presented with C1-2 rotatory subluxation. Traction was able to reduce the atlanto-axial joint in all cases. Based on imaging, history, exam, and laboratory results, they were diagnosed with JRA. After reduction of the atlantoaxial joint, they were transitioned to a halo vest and disease-modifying antirheumatic drugs (DMARDs). The older 2 children underwent C1-2 fusion. The younger child has minimal symptoms and has not undergone surgical intervention 4 years from initial presentation. Rotatory subluxation can be the first presenting sign of JRA. Younger children may be able to be treated conservatively with traction and medication, while older children may require occiput to C2 fusion due to bony destruction and basilar invagination. IV.
Regional and Seasonal Trends in Tropical Ozone from SHADOZ Profiles: Reference for Models and Satellite Products

Understanding trends in lowermost stratosphere (LMS) and free tropospheric (FT) ozone is an important topic in the climate assessment community because of feedbacks among changing temperature, dyna...
Radio Consumption and Perception

Radio Consumption and Perception is a research study probing the social and moral values conveyed to audiences through broadcast radio. The uses and gratifications theory provides insight into the exchange of information reciprocated through disc jockeys, and their viewership. This examination incorporates an ethnographic interview-style using the snowballing technique, of 15 core open-ended questions, for honest and casual answers from respondents in their environments. The researcher, Yerodin Carrington, has never seen nor met anyone of the personalities of the Ebro in the Morning show. There is no association with anyone employed at WHQT-FM, Emmis Communications, or the personalities of Ebro in the Morning. However, Yerodin Carrington found viewers enjoyed the messages disc jockeys conveyed on-air through segments, their form of expression in a relatable manner, and the clarification of press releases for the understanding of their viewership. Further research is suggested with room for negative feedback, a competitive source, and a whacking variety of radio listeners for precise findings will be needed.
Ceftolozane/tazobactam for refractory P. aeruginosa endocarditis: A case report and pharmacokinetic analysis.

Abstract We describe a case of a 48 years old male with left sided endocarditis and septic emboli secondary to a Pseudomonas aeruginosa strain that developed resistance to other β-lactam antibiotics during therapy resulting in prolonged bacteremia. Blood cultures sterilized within 1 day of initiating ceftolozane/tazobactam 3 g every 8 hours in combination with ciprofloxacin. Steady state free ceftolozane plasma Cmax and Cmin concentrations were calculated to be 122.2μg/mL and 24.3μg/mL, respectively. The multidrug-resistant strain harbored chromosomal β-lactamases OXA-486 and PDC-3, mutations in ampD and dacB predicted to lead to ampC over-expression, and mutations in OprD predicted to decrease outer membrane permeability. Following completion of a 42 day course and aortic valve replacement, the patient was deemed clinically cured without recurrence of infection at follow up 2 years later. To our knowledge, this is the first reported case to measure ceftolozane concentrations during the treatment of endocarditis which supports dose optimization approaches of severe endovascular disease due to multidrug resistant pathogens.
Mathematical modeling predicts exponential growth kinetics for metastases in the lymphatic vessels in the absence of vascularization

The major cause of death from cancer is metastasis. In the lung, metastases can form in the lymphatic vessels or the lung parenchyma. The presence of cancer metastases in the lung lymphatics indicates poor outcome and rapid disease progression in patients. This is recapitulated in a mouse model, where breast cancer metastases in the pulmonary lymphatics grow larger than metastases in the lung parenchyma, without vascularization. To explain rapid growth of metastases in the lymphatics in the absence of angiogenesis, we have developed a 3D mathematical model of intralymphatic tumor growth. This is a deterministic continuum model based on partial differential equations used to describe avascular tumor growth, adapted to reflect the unique architecture of the lymphatic vasculature. Our model predicts that the cylindrical shape of the lymphatic vessel, which constrains growth of the tumor in two dimensions but allows indefinite growth along the vessel, enables oxygen levels to remain relatively high throughout the tumor. The greater diffusion coefficient of oxygen in lymph further improves oxygenation of intralymphatic metastases which rarely become hypoxic. Improved tumor oxygenation leads to decreased tumor cell death and a rapid increase of metastatic burden in the lymphatics. Importantly, our model further predicts that the kinetics of growth of intralymphatic metastases are exponential. This contrasts the established view that all tumors follow Gompertzian growth kinetics, i.e. , that tumor growth rate decreases as tumor size increases and that angiogenesis is required for progressive growth. These findings explain rapid growth of metastases in the absence of angiogenesis and indicate that the lymphatic niche is a favorable environment for metastatic growth. Our predictions also suggest that therapeutics targeting intralymphatic tumors should be optimized to the specific tumor microenvironment.
Real-time, low-cost, due regard radar target simulation

A low-cost Radar Target Simulator (RTS) lab tool is being developed for General Atomics Aeronautical Systems, Inc. (GA-ASI) in an undergraduate-industry partnership. For proof-of-concept, the RTS is being constructed from commercial off-the-shelf (COTS) components and is designed to provide synthetic target returns to GA-ASI's Due Regard Radar (DRR). Its architecture accommodates future improvements allowing the testing of other families of GA-ASI radars. The RTS functions as a Digital Radio Frequency Memory (DRFM), using a command line interface to create an airspace model. The RTS provides returns mimicking real world targets. The user has freedom to adjust parameters of Radar Cross-section (RCS), range, and velocity, allowing for comprehensive simulation of a wide variety of air-to-air scenarios.
Discriminative validity of the general behavior inventory using youth report.

The present study investigated the ability of the General Behavior Inventory (GBI) to discriminate between diagnostic groups using youth self-report. One hundred and ninety-seven youths ages 10–17 years presenting at a midwestern urban outpatient clinic specializing in mood disorders completed the GBI as part of the intake process. Diagnoses were determined by a structured clinical interview (K-SADS) administered by either a child and adolescent psychiatrist or a research assistant trained to a high level of interrater reliability (κ > .85). Games–Howell post hoc tests showed that the diagnostic groups significantly differed on the GBI's 2 subscales, Depression and Hypomanic–Biphasic. Logistic regression demonstrated that the scales discriminated between bipolar and disruptive behavior disorders, unipolar and bipolar depression, and mood and disruptive behavior disorders or no diagnosis. Receiver Operating Characteristic (ROC) curves further indicated the good diagnostic efficiency of the scales. Results indicate that the GBI's subscales might aid in making traditionally difficult differential diagnoses, such as between bipolar disorder and Attention Deficit Hyperactivity Disorder (ADHD) and between unipolar and bipolar depression.
Caffeine inhibition of fertilization in Arbacia; electron microscopy.

This study of the effect of caffeine upon the physiological processes underlying fertilization in the Arbacia egg by means of the physical changes in the finer structure of the cell, as revealed by electron microscopy, indicates the following. Negative results were obtained with reference to mitochondria and to the beaded, sheet-partition-like, double membranes scattered through the cytoplasm. These structures have been called sheets, fibers, endoplasmic reticulum, etc. These synonomous terms of different authors have been shown by Bernhard et al. (2) to be basophilic substances. No evidence was obtained that caffeine affects them. Positive results were observed showing caffeine effects as follows: 1. 1. The most drastic alteration of the ultramicroscopic structure of the mature, unfertilized Arbacia egg as shown by the electron micrographs of caffeine-treated eggs, is the disappearance of the papillated surface border. 2. 2. The degree of modification of the finer structural details is directly proportional to the concentration of the caffeine employed. 3. 3. The groundwork matrix of the egg becomes more compact and more minutely vacuolated. 4. 4. Pigment granules possess a double membrane which becomes more permeable to the release of echinochrome molecules; and the granule itself becomes swollen. 5. 5. The cortical granule matrix, especially the “Hub” area of the wheel-like “Hub” and “Spokes” configuration of the normal cell, becomes disorganized into one of three variations of its original form. 6. 6. An explanation is suggested for the change in the papilla-like border.
Bomb‐Pulse Dating

Atmospheric testing of nuclear weapons during the 1950s and early 1960s doubled the concentration of carbon-14 atmosphere and created a pulse that labeled everything alive in the past 50 years as carbon moved up the food chain. The variation in carbon-14 concentration in time is well documented and can be used to chronologically date all biological materials since the mid-1950s. Keywords: radiocarbon; bomb-pulse; carbon-14; dating; isotope forensics
Aggregation methods for information fusion and decision making

Intelligent decision-making requires the use of all available information. However the information used for decision-making generally comes from multiple sources and is expressed in various modalities. We are interested in the problem of multi-source information fusion in the case when the information provided has some uncertainty. In order to address this problem we need to provide methods for the representation of different types of uncertain information. Here we shall discuss some computational intelligence based approaches for attaining this capability. One approach we consider is the use of a set measure for the representation of uncertain information. We shall also look at some aggregation approaches for the fusion of this information.
A Statistical Method for Correlating Paired Wave Spectra

AbstractOcean wave spectra are complex. Because of this complexity, no widely accepted method has been developed for the comparison between two sets of paired wave spectra. A method for intercomparing wave spectra is developed based on an example paradigm of the comparison of model spectra to observed spectra. Canonical correlation analysis (CCA) is used to investigate the correlation structure of the matrix of spectral correlations. The set of N ranked canonical correlations developed through CCA (here termed the r-sequence) is shown to be an effective method for understanding the degree of correlation between sets of paired spectral observation. A standard method for intercomparing sets of wave spectra based on CCA is then described. The method is elucidated through analyses of synthetic and real spectra that span a range of correlation from random to almost equal.
Deamination of protein lysyl epsilon-amino groups by peroxidase in vitro.

Peroxidase, catechol, and hydrogen peroxide were shown to react with proteins, causing a decrease in lysine detectable after acid hydrolysis. The loss of lysine did not occur in the presence of benzenesulfinic acid which suggested that the quinones formed by peroxidase had oxidized some lysyl residues to lysyl aldehyde that formed a cyclic ninhydrin negative Shiff's base. When peroxidase treated protein was oxidized with performic acid prior to hydrolysis a new ninhydrin positive compound was found, which was shown by cochromatography and mass spectroscopy to be α-aminoadipic acid. The α-aminoadipic acid recovered accounted for (20–40)% of the lysine lost.
94.6% peak efficiency DCM buck converter with fast adaptive dead-time control

This paper presents a dynamic logic based adaptive dead-time control circuit (DADTC) for fast and adaptive control to minimize body diode conduction losses and dead-time of the buck regulator operating in discontinuous conduction mode (DCM). Dead-time is an important metric for improving efficiency of low voltage converters. DADTC provides instant sensing and feedback based on the load to minimize dead-time significantly compared to prior art and enables higher overall power efficiency of the converter. Further, the presented buck converter has inherent pulse skipping mode to lower the switching frequency at light loads further enhancing light load efficiency. The buck regulator was fabricated in 0.35 μm CMOS process with an input voltage range of 1.8V-3V and load current range of 1mA-200mA. Measurement results show that the proposed design achieves peak power efficiency of 94.6% and a high overall power efficiency ( > ~89%) for load currents greater than 5mA with a sensing delay of only ~5ns for VIN = 1.8V.
Joint Wind-Snow Hazard Characterization for Reduced Reference Periods

AbstractThe joint behavior of snow and wind actions on structures becomes relevant for design in many regions of North America. With trends toward performance-based design for loads/actions arising from natural hazards, information is needed on both individual and joint hazards, e.g., at different hazard levels, exceedance probabilities, or mean recurrence intervals. The writers have developed one approach for two hazards that can be well modeled by sparse processes and have also developed recommendations for joint hazard characterization for the case of a full (e.g., 50 years) design life. The present paper shows how these findings can be extended to provide useful information for joint hazard characterization in shorter reference periods. This can be useful, for example, in the design (single or multiobjective) of formwork or other temporary structures in high wind/snow regions.
Prolongation of γ-aminobutyric acid-mediated inhibitory postsynaptic potentials by 4,5,6,7-tetrahydroisoxazolo[4,5-c]pyridin-3-ol (THPO)

The effects of 4,5,6,7-tetrahydroisoxazolo[4,5-c]pyridin-3-ol (THPO), an inhibitor of gamma-aminobutyric acid (GABA) uptake, were examined in the rat hippocampal slice and compared to the actions of the potent GABA uptake inhibitor, cis-4-OH-nipecotic acid. THPO reversibly prolonged GABA-mediated inhibitory postsynaptic potentials (IPSPs) but did not prolong conductance changes evoked by iontophoresed GABA. In contrast, cis-4-OH-nipecotic acid prolonged responses to iontophoresed GABA but had little effect on IPSPs. THPO reduced the intensity of spontaneous epileptiform bursts observed in elevated (8.5 mM) potassium; this effect was absent after addition of 100 microM bicuculline. These results suggest that drugs similar to THPO may be useful for enhancing GABA-mediated inhibition, but that THPO acts by a mechanism distinct from that of the GABA uptake inhibitor, cis-4-OH-nipecotic acid.
Minimal Differentiation at the Top

Rooted in the economics of industrial organization, the principle of differentiation ranks as one of the fundamental tenets of competitive strategy. However, while differentiation may be an intuitive means of averting vigorous price competition, casual observation reveals that firms often sell similar, if not perfectly identical, product features. This paper examines the effect of (possibly tacitly) collusive pricing on product location choices in a vertical differentiation framework: when firms are able to successfully collude on price, they minimally differentiate at the top of the vertical spectrum. While firms jointly earn first-best profits, overall welfare is unambiguously lower.
Ordered and Sequential Binding of DnaA Protein to oriC, the Chromosomal Origin of Escherichia coli

DnaA protein of Escherichia coli acts in initiation of chromosomal DNA replication by binding specific sequences, termed DnaA boxes in the chromosomal origin, oriC. On binding, it induces a localized unwinding to create a structure recognized by other replication proteins that act subsequently in the initiation process. In this report, we examined the binding of DnaA protein to each of the DnaA boxes in oriC. By gel mobility shift assays, DnaA protein formed at least six discrete complexes. ATP or ADP included in the reaction mixture prior to electrophoresis was required. Chemical cleavage of isolated complexes with 1,10-phenanthroline-copper revealed that DnaA protein binds in an ordered manner to the DnaA boxes in oriC. Preferential binding to one DnaA box (R4) was confirmed by demonstration that a DNA fragment containing it was bound with greater affinity than another DnaA box sequence (R1). In vitro replication activity correlated with a complex formed at a ratio of 30 DnaA monomers/oriC in which all DnaA boxes are occupied. The last site bound is DnaA box R3. This event may be critical in promoting initiation from oriC as it correlates with in vivo observations that binding of DnaA protein to box R3 occurs at the time of initiation of chromosomal replication, whereas other DnaA boxes are bound by DnaA protein throughout the cell cycle (Cassler, M. R., Grimwade, J. E., and Leonard, A. C. (1995) EMBO J. 14, 5833-5841).
Contingency and Serendipity in the Reactions of Fischer Carbene Complexes with Conjugated Triynes

The first examples of reactions of Fischer carbene complexes with triynes are reported. The regioselectivity of the reaction of the two different alkyne functions in the symmetrical triyne depends on the nature of the substituent of the triyne. Bis-silyl-substituted triynes react at the central alkyne unit, whereas bis-aryl- and bis-alkyl-substituted triynes react at the end alkyne unit. The reaction of a Fischer carbene complex with a phenyl substituent also reacts with a bis-silyl-substituted triyne at the central alkyne unit but gives a furan product rather than the normal phenol product. It was also demonstrated that all three of the alkyne units in conjugated triynes could react in turn with a Fischer carbene complex to give access to trisquinones.
Retinoid acid esterase activities: tissue and subcellular distribution in mice.

Abstract Methyl retinoate, ethyl retinoate and a trimethylmethoxyphenyl (TMMP) analog of ethyl retinoate are cleaved by enzymes widely distributed in tissues of mice; brain, liver and ovary contain high activity and plasma contains low activity for all three substrates. In the lung, enzymatic activity is primarily localized in the microsomal fraction, with some activity also in the soluble cytoplasmic fraction. From studies on subcellular distribution, the effect of pH, sensitivity to inhibitor and thermal stability, it appears that there are several esterases that act upon retinoid acid esters.
Nonlinear tuning curve vibration response of a buried landmine

Measurements of the acoustic impedance of a VS 2.2 anti-tank plastic landmine reveal significant resonances in the frequency range between 80 and 650 Hz. The top surface resonances are due to its complicated mechanical structure vibrating in air. The lowest mode of the landmine results in a high Q simple harmonic oscillator resonance of the top surface, which behaves like a rigid mass. At higher frequencies the top surface behaves like thin circular plat acoustic modes. When these landmines are buried in soils, the modes are mass loaded. Resonances from measurements of the normal component of the acoustically induced soil surface particle velocity (due to sufficient acoustic-to-seismic coupling) are used for detection schemes. Since the interface between the top plate and the soil responds to pressure fluctuations nonlinearly, characteristics of landmines, the soil, and the interface are rich in nonlinear physics and allow for new methods of buried landmine detection not previously exploited. Here, the structure of a family of resonant tuning curves for relatively low amplitude, but nonlinear drive levels, reveals the “nonclassical” nonlinear resonant behavior of the soil-landmine oscillator.
Nitric oxide regulates insulin secretion in the isolated perfused human pancreas via a cholinergic mechanism.

Background. The purpose of this study was to determine whether nitric oxide regulates insulin secretion in the isolated perfused human pancreas. Methods. Single-pass perfusion was performed in four pancreata with a modified Krebs medium. Sequential 10-minute infusions (separated by 10-minute basal periods) of (1) 25 nmol/L acetylcholine, (2) 2.5 μmol/L acetylcholine, and (3) 16.7 mmol/L glucose were initially infused. Then 0.1 μmol/L of NG-monomethyl- l -arginine (NMMA) was infused during a period of 10 minutes, and steps (1) through (3) were repeated. The change in insulin secretion from basal levels during each stimulation was calculated and compared with that seen after NMMA infusion. Results. Infusion of 25 nmol/L and 2.5 μmol/L acetylcholine resulted in a significant stimulation of insulin secretion before NMMA infusion (p Conclusions. These data show that infusion of the nitric oxide synthase inhibitor NMMA suppressed cholinergic-stimulated insulin secretion but did not affect glucose-stimulated insulin secretion. We conclude that nitric oxide regulates insulin secretion in the isolated perfused human pancreas.
Socio‐economic Restructuring and Vulnerability to Environmental Hazards in Bulgaria

The restructuring of Bulgaria's social, economic and political system includes a change in the way it handles disaster preparation and response. During the Cold War, the entire country drilled regularly in civil defense, which was under the control of the army. A recent decree and pending legislation transfers civil defense from the military to the Council of Ministers, which has developed a national plan for defense against environmental hazards. This research shows that the transformation from command to market economy, plus the country's severe economic crisis, is degrading existing civil defense structures, preventing the implementation of the proposed new organization and increasing the population's vulnerability to hazards. Case studies of a small city, a petrochemical complex, coastal-zone hazards management, earthquake hazards regulation and the Kozloduy nuclear facility demonstrate Bulgaria's increasing vulnerability to environmental hazards.
Women in nephrology: one mother's strategies for success in academic medicine.

y goal when I applied for a fellow-ship position in nephrology was to become an academic nephrologist doing research, clinical work, and teaching; and that is where I am. However, most of the particulars are not what I would have pre-dicted. I initially planned to do bench research, since that had been my prior experience, and that was the usual model for an academic nephrolo-gist. But somewhere toward the end of residency, I decided that clinical research was what I really wanted to do, so I set out to find a mentor and the necessary training. I was extremely fortunate to have chosen the University of California, San Francisco (UCSF), for my fellowship training, because formal training in clinical research was available even in 1995. Until we had children, my biggest challenge in nephrology stemmed not from my being a woman but from my choice to pursue clinical research, and, in particular, studies that focus on areas not directly related to kidney function or its replacement—that is, muscle function and physical functioning. These studies often fall outside traditional nephrology study sections, but also outside more basic exer-cise physiology study sections as well, because of the focus on a chronic disease population. Until recently, the idea of work that was clinical but had a laboratory component was foreign to many in academic nephrology, so I struggled to find a proper niche within the nephrology community and within the National Institutes of Health study section structure.Before I share my ‘recipe’ for academic suc-cess as a woman in nephrology, a brief discus-sion of why this is (or isn’t) a women’s issue seems in order. I believe that men with families are increasingly facing issues of family/life bal-ance as well, but if one looks at the statistics, women seem to be affected to a greater degree. According to the American Association of Medical Colleges, women accounted for more than 50% of instructors and 40% of assistant professors in United States medical schools in 2007 but less than 30% of associate professors and only 17% of professors.
Performance of a bedside C-reactive protein test in the diagnosis of community-acquired pneumonia in adults with acute cough.

Abstract Purpose To evaluate the performance of a rapid, bedside whole blood C-reactive protein test as a diagnostic test for pneumonia in adults. Methods We enrolled consecutive adults who presented with acute cough (duration ≤3 weeks). A fingerstick blood specimen for C-reactive protein level was obtained. Patients also provided information about demographic characteristics and symptoms. Physical examination findings, diagnoses, and treatments were abstracted from the medical record; illness duration and subsequent office visits were determined with follow-up telephone calls. A clinical prediction rule for pneumonia was calculated for each patient and compared with C-reactive protein levels. Results Twenty (12%) of the 168 patients in the study had radiographic evidence of pneumonia. Median C-reactive protein levels were significantly higher for patients with pneumonia than in the remaining patients (60 mg/L vs. 9 mg/L, P Conclusion C-reactive protein levels could be a valuable addition to clinical prediction rules for pneumonia. A C-reactive protein level ≥100 mg/L might be a useful indication for chest radiography or empiric antibiotic therapy when the diagnosis of pneumonia is in doubt.
The Ion Beam Compressor for Pellet Fusion

Intense ion beams of short duration can be created by charge exchange injection into a number of small, high field storage rings. If the beams are extracted and focussed from many directions simultaneously onto a DT pellet, a beam of protons or a particles of 15,000-30,000 A for a duration of 1-2 ns can result. Such beams have possibilities for compressing and heating to fusion temperatures submillimeter pellets of a DT mixture. The potential of this method is discussed.
The Distribution of the Product of Ranges in Samples from a Rectangular Population

(1951). The Distribution of the Quotient of Ranges in Samples from a Rectangular Population. Journal of the American Statistical Association: Vol. 46, No. 256, pp. 502-507.
Surface-exposed proteins of 3T3-L1 adipocytes: identification of phosphorylated, insulin-translocated, and recycling proteins.

Abstract Twenty-seven adipocyte-specific, cell surface-exposed proteins were detected by derivatizing undifferentiated and differentiated 3T3-L1 cells with membrane impermeant sulfosuccinimidyl 2-(biotinamido)ethyl-1,3-dithiopropionate at 0 °C. Biotinylated proteins were adsorbed onto streptavidin-agarose, resolved on two-dimensional polyacrylamide gels, and detected by autoradiography or silver staining. Of the surface-exposed proteins specific to adipocytes, three were phosphorylated and seven were glycoproteins that bound to wheat germ agglutinin and eluted with N-acetylglucosamine. Eleven of the adipocyte-specific proteins were bound to streptavidin-agarose after the cells were biotinylated at 20 °C and then stripped with glutathione at 0 °C to isolate plasma membrane proteins that localize to recycling endosomes as well as the cell surface. When insulin-deprived cells were acutely treated with insulin, only a few proteins, including one protein tentatively identified as the GLUT4 glucose transporter, were found to increase in concentration at the cell surface. These latter results imply that up-regulation of glucose transport by the translocation of GLUT4 to the cell surface in response to insulin occurs by exocytic fusion of an intracellular compartment having a limited number of proteins.
Hormonal therapy of prostatic carcinoma: is there a rationale for delayed treatment?

Le traitement hormonal tardif est superieur au traitement hormonal precoce a la condition que les pourcentages des cellules sensibles et insensibles aux hormones ne se modifient pas significativement au cours de la vie
Effect of electrostatic interactions on transmission of PEGylated proteins through charged ultrafiltration membranes

Abstract Recent experiments have demonstrated that PEGylated proteins, produced by covalent attachment of a polyethylene glycol chain to a native protein, can be purified using negatively charged ultrafiltration membranes. However, the nature of the electrostatic interactions governing the transmission of these PEG–protein complexes during ultrafiltration has not been examined. Experimental data were obtained for the transmission of PEGylated α-lactalbumin through both unmodified and negatively charged composite regenerated cellulose membranes over a range of solution ionic strength. The effect of the polyethylene glycol on the protein was also studied by measuring the electrophoretic mobility of both PEGylated and acetylated versions of the α-lactalbumin. The attachment of the PEG altered the protein charge, the effective size, and the electrostatic potential surrounding the protein. The PEGylated α-lactalbumin was strongly retained by the negatively charged membrane due to the significant electrostatic interactions in this system. The data were consistent with a simple model of the PEGylated protein as an effective hard sphere with the surface charge shifted to the outer edge of the PEG by accounting for the alteration in the electrostatic potential associated with the reduced electrolyte concentration within the PEG layer. These results provide important insights into the role of electrostatic interactions on the retention of PEGylated proteins during ultrafiltration.
The organisation of the gingival vasculature.

Vascular perfusion, vital microscopy and conventional histologic techniques were applied to a study of the structure and organisation of vessels in gingiva with no previous history of inflammation. The gingival vasculature around deciduous teeth of cats and dogs was found to be classifiable as a microvascular bed, containing arterioles, precapillary venules and venules less than 501974m in width. Capillaries predominated within crestal gingiva and within the superficial buccal and crevicular networks. Precapillary arterioles and postcapillary venules were most common in the mid gingival region. Small arterioles and venules were present in apical gingiva. Capillaries, comprising the network in crestal gingiva, were arranged as interconnecting repetitive units. Changes in the width, length and local morphology of vessels in each unit, with inflammation, resulted in the formation of vessel loops. With continuing inflammation, certain connecting vessels were lost while other vessels became spatially rearranged.
Data Requirements and Data Processing Earth Resources Surveys

The basic physical quantity measured by earth resources survey optical instrumentation is the average scene spectral radiance in a field-of-view patch, modified by atmospheric transmittance. Often this spectral radiance is integrated over a band of wavelengths; the sensor then yields a band average of spectral radiance. Primary additional information is contained in the spatial distribution of this radiance, i.e., the scene geometry, and the time of day and year of the scene record. These statements apply to the broad class of photoelectronic imaging systems, including emulsion, photocathode, photovoltaic, and photoconductive sensors in a variety of scanning and non-scanning instruments.