cssi/SciSciGPT-SciSciNet huggingface dataset:
Evaluation of 4h SiC bipolar junction transistors

4H-SiC bipolar junction transistors (BJTs) demonstrate excellent current carrying and blocking capabilities, and offer good high-temperature performance. Moreover, these devices are easier to parallel than their Si analogues due to negative current gain temperature coefficient. In contrast to vertical MOSFETs and JFETs, these devices do not have junction discontinuities in the active region, which makes these devices easily scalable to high blocking voltage requirements. This experiment will help determine the safe operating areas of 1 mm2, 4 mm2, 9 mm2, and Darlington structure SiC BJTs constructed by CREE. The eventual goal of this work is to produce devices capable of blocking 1200 V and operating at a maximum collector current of 10 A. Ideally gains of 8 or more are desired at temperatures of 150degC. These devices will be characterized at temperatures up to 150degC. Next they will be put into a system containing a push-pull circuit, which will be used in to control the on and off states of the BJT under test. This report will serve as to document the operational status of the present devices and as feedback to CREE in order to guide the production of future devices. These devices were tested using single-shot and repetitive pulsing. The devices were tested individually, as well as in parallel pair configurations. During each of these experiments the devices were tested from room temperature to 150degC
Ex situ hydrodeoxygenation in biomass pyrolysis using molybdenum oxide and low pressure hydrogen

Biomass pyrolysis vapors were hydrodeoxygenated using MoO3 and low pressure H2 (1.8 bar Ptotal) in a tandem microreactor. High yields of mostly linear alkanes (C1–C6) and aromatics were achieved from the pyrolysis of cellulose, lignin, and corn stover feedstocks.
Interacting at a Distance Using Semantic Snarfing

It is difficult to interact with computer displays that are across the room, which can be important in meetings and when controlling computerized devices. A popular approach is to use laser pointers tracked by a camera, but interaction techniques using laser pointers tend to be imprecise, error-prone, and slow. Therefore, we have developed a new interaction style, where the laser pointer (or other pointing technique such pointing with a finger or even eye tracking) indicates the region of interest, and then the item there is copied ("snarfed") to the user's handheld device, such as a Palm or PocketPC handheld. If the content changes on the PC, the handheld?s copy will be updated as well. Interactions can be performed on the handheld using familiar direct manipulation techniques, and then the modified version is sent back to the PC. The content often must be reformatted to fit the properties of the handheld to facilitate natural interaction.
Transfer of the drug-resistance transposon Tn5 toErwinia herbicola and the induction of insertion mutations

Translocatable drug-resistance element (transposon) Tn5 was transferred through conjugation from its carrier “suicidal” plasmid pJB4JI, harbored byEscherichia coli, toErwinia herbicola. The frequencies of transfer ranged from 0.4×10−8 to 26×10−8 per recipient cell. Membrane filter mating yielded more transconjugants than the spread plate technique. Several insertion mutations resulting in loss of bacteriocinogenicity were detected. The location of Tn5 in the mutant genomes was determined by Southern blot hybridization using Tn5-containing pRZ102 as the32P-labelled probe. The resulting autoradiogram showed specific hybridization with a 96 megadalton plasmid in nine mutants ofErwinia herbicola out of ten tested. However, in one mutant, the 96 megadalton plasmid was missing; instead a larger plasmid containing Tn5 was apparent which was not present in the original strain. This plasmid may have arisen by dimerization of the 96 megadalton plasmid as a result of Tn5 insertion. Using this method, we show that the insertion of Tn5 in that plasmid may have caused the loss of bacteriocinogenicity. The potential usefulness of this technique in genetic analyses of otherErwinia species and other phytobacteria is discussed.
Reynolds number effect on leading edge film effectiveness and heat transfer coefficient

Abstract The effect of mainstream Reynolds number on leading edge heat transfer coefficient, film effectiveness, and heat flux was experimentally studied. Data were obtained for several combinations of film hole shapes and spacings, film hole row locations, blowing ratios, and mainstream turbulence levels at the Reynolds numbers of 100000, 40 000, and 25 000. Representative results from 3- d and 4- d spaced two row injections, at the intermediate blowing ratio of 0.8, with and without turbulence grid are presented. Both heat transfer coefficient and film effectiveness increase with Reynolds number. A Reynolds number of 100000 produces the lowest heat flux ratio in most of the leading edge region.
Liquid-vapor equilibrium of dilute aqueous solutions of methanol

Numerous sets of vapor pressure-composition data for methanol in dilute aqueous solutions at 25°C and 35°C have been obtained with an automated vapor pressure apparatus developed in this laboratory. Activity coefficients of both components and values of the pairwise free energy of interaction of methanol molecules have been inferred from the results. The osmotic second virial coefficient of methanol has also been calculated and compared with literature values of this quantity.
Good Things to Those Who Wait? National Elections and Government Respect for Human Rights:

What exactly is it about democracy that enables it to protect human rights? As part of the research program addressing that important question, this article examines the relationship between democratic national legislative and presidential elections and government respect for human rights in over 100 countries from 1981 to 2000. Both presidential (direct and semi-presidential) and lower-house national legislative elections are found to be reliably associated with greater government respect for human rights, but only in the years following an election and not in election years themselves. Interestingly, national legislative elections were found to be associated with greater government respect for human rights, while presidential elections were associated with less respect for human rights. Consequently, the authors caution that the historically popular concept of electoralism (the use of elections alone as a proxy for full democracy) is unlikely to play a positive part in any policy intending to protect hu...
Rough sets and information retrieval

The theory of rough sets was introduced [PAWLAK82]. It allows us to classify objects into sets of equivalent members based on their attributes. We may then examine any combination of the same objects (or even their attributes) using the resultant classification. The theory has direct applications in the design and evaluation of classification schemes and the selection of discriminating attributes. Pawlak's papers discuss its application in the domain of medical diagnostic systems. Here we apply it to the design of information retrieval systems accessing collections of documents. Advantages offered by the theory are: the implicit inclusion of Boolean logic; term weighting; and the ability to rank retrieved documents. In the first section we describe the theory. This is derived from the work by [PAWLAK84, PAWLAK82] and includes only the most relevant aspects of the theory. In the second we apply it to information retrieval. Specifically, we design the approximation space, search strategies as well as illustrate the application of relevance feedback to improve document indexing. Following this in section three we compare the rough set formalism to the Boolean, vector and fuzzy models of information retrieval. Finally we present a small scale evaluation of rough sets which indicates its potential in information retrieval.
Situating CoWeb: a scholarship of application

Since 1998, we have been developing and researching CoWeb, a version of Wiki designed to support collaborative learning. In this article, we summarize our results of situating CoWeb across the academic landscape of Georgia Tech. In architecture, CoWeb enabled faculty to serve more students in a design-based course. In English composition, a comparison study demonstrated significant learning benefits without incurring disproportionate costs. Yet, situating CoWeb was not always successful. In many STEM (Science, Technology, Engineering, and Mathematics) classes, students actively resisted collaboration. From these studies, we conclude that the culture of the classroom and the discipline needs to be compatible with the medium for computer-supported collaborative learning to be effective. Finally, we demonstrate how collaboration can be designed into the culture. A new class on introductory computing was explicitly designed to take advantage of the collaborative possibilities that CoWeb affords. We report our findings of the success of this approach. We characterize this research as a scholarship of application. We demonstrate that this mode of scholarship is a viable mode of scholarship in the learning sciences. Unlike traditional scholarship of discovery, we are not solely concerned with discovering new knowledge. Instead, we support others in the application of a new technology to serve genuine and complex learning situations. By doing so, we seek to understand the potential that one new medium, a Wiki, has for supporting learning.
Structure and function of the sinus node, AV node and His bundle of the human heart: part I-structure.

In the human heart, the sinus node has 2 equally important functions. The first of these is to provide a steady repetitive signal that produces the heart beat and is familiarly called “normal sinus rhythm.” The second principal function is an intermediary one in which normal sinus rhythm can be accelerated or slowed to provide an optimal rate for the most effective cardiac output. Signals for this intermediary purpose fall into 2 broad categories, those provided by the autonomic nervous system and those provided by substances delivered in the blood stream through the sinus node artery. This normal intermediary function is a stark contrast to electronic pacemakers, and this matter is further discussed later. Autonomic neural signals are almost entirely from the vagus nerve or a sympathetic nerve. There is also a much smaller group of different neural transmitters such as serotonin73 or histamine74 or nucleosides and nucleotides75; however, it is doubtful whether either these or other such substances are significantly delivered from nodal nerve terminals. Neural signals can come directly from the brain as a cognitive function such as fear or apprehension or anger, but they can also be generated by a wide variety of reflexes notably including 2 that actually originate in the heart itself. The first of these is inhibitory in nature (vagally mediated) and is known as the von Bezold-Jarisch reflex66 frequently accompanying acute posterior myocardial infarction.76 The second is a much more powerful cardiogenic hypertensive chemoreflex77 readily demonstrable in canine experiments wherein central aortic pressure can double within 4 to 6 seconds. Additional details including the location of origin within the heart,77 neural pathways traversed in either the afferent or efferent routes,78 and the usual chemical signal stimulating these 2 reflexes77 and their chemical blockade79 are published as cited. Humoral substances influencing function of the sinus node include ones normally provided in the body, such as circulating catecholamines, glucagon, or various nucleosides or nucleotides. Humoral substances may also be provided by willful ingestion of narcotics80,81 or prescribed medications7,82 or by administration during medical procedures such as anesthesia.83
Time-average Fourier telescopy: a scheme for high-resolution imaging through horizontal-path turbulence

The problem of high-resolution imaging through long horizontal-path ground-level turbulence has gone unsolved since it was first addressed many decades ago. In this paper I describe a method that shows promise for diffraction-limited imaging through ground-level turbulence with large (meters) apertures and at large (kilometers) distances. The key lies in collecting image data in the spatial frequency domain via the method of Fourier telescopy and taking suitable time averages of the magnitude and phase of the Fourier telescopy signal. The method requires active illumination of the target with laser light, and the time averages required will likely be over many tens of seconds if not tens of minutes or more. The scheme will thus not be suitable for time-varying scenes. The basic scheme is described, and principle challenges briefly discussed.
The Q-T interval in myocardial infarction and left ventricular hypertrophy

Abstract 1. 1. By the use of semilogarithmic plotting, the Q-T formula of Ashman is simplified and reduced to a straight line. 2. 2. In 120 cases of left ventricular hypertrophy, no significant prolongation of the Q-T interval was found. 3. 3. In eighty-six cases of acute myocardial infarction, the Q-T interval was significantly prolonged. The data did not confirm a previous report that the prolonged Q-T interval is gradually reduced during the first few weeks after myocardial infarction.
Neonatal mortality rates among growth-discordant twins, classified according to the birth weight of the smaller twin.

Abstract Objective The purpose of this study was to evaluate neonatal mortality rates among discordant twins, classified according to the birth weight of the smaller twin. Study design We compared neonatal mortality rates among three groups of discordant twins (>25%), distinguished by the birth weight of the smaller twin being 50th percentile. Results Among the 10,683 pairs of twins who were studied, the respective proportions of the three groups were 62.4%, 32.9%, and 4.7%. The neonatal mortality rate was significantly higher among pairs in which the smaller twin weighed Conclusion Severely discordant twin pairs in whom the smaller twin is also small for gestational age are at an increased risk of neonatal death. Identification of this group is an imperative step in the management of birth weight discordance in twin gestations.
Psychosocial distress in patients presenting with voice concerns

Summary Objectives To assess the prevalence of psychosocial distress (depression, anxiety, somatization, and perceived stress) in a consecutive sample of patients presenting with voice concerns and to qualitatively analyze patient comments on challenges associated with voice problems. Study Design Cross-sectional study. Methods New patients presenting to a multidisciplinary voice clinic with voice concerns were invited to participate. Respondents (n = 197) completed the Brief Symptom Inventory 18-item scale, the 4-item Perceived Stress Scale, and the Voice Handicap Index 10-item scale. Qualitative analysis was performed of responses to an open-ended question about challenges associated with a voice problem. Results Approximately one-third (32%) of the patients met the strict case criteria for depression, anxiety, and/or somatic concerns based on the Brief Symptom Inventory 18-item scale. Most patients had no prior diagnosis of depression or anxiety, and the degree of distress was not predicted by the type of voice-related diagnosis. Perceived stress was higher among female patients ( P = 0.02). As expected, scores on the Voice Handicap Index 10-item scale were indicative of concurrent voice-related handicap (mean, 19.5; standard deviation, 9.4). In qualitative analysis of responses regarding challenges associated with a voice problem, 19 themes were identified (eg, threat to occupational functioning). Conclusions These findings identify a high prevalence of multiple types of distress among patients with voice disorders, presenting an opportunity to provide more comprehensive care to this patient population.
Frequency and Duration Methods for Power System Reliability Calculations: II - Demand Model and Capacity Reserve Model

This paper is a continuation of the work started in [1] and is aimed at incorporating a model of the power system load with the generation system model developed previously. Combination of this load and the generation model permits computation of the availability, frequency of occurrence, and mean duration of generation reserve, or margin states. The results of this work are illustrated by continuation of a simple numerical example begun in Part I. The most widely applied of the previously developed techniques for assessing generation system reliability, the loss-of-load and loss-of-capacity methods, assume fixed outage or load duration intervals. The present model, on the other hand, uses an exponential distribution of durations. The reserve margin states developed using the exponential distributions contain data giving both the availability of each margin state and the expected frequency of recurrence. Previous methods yield only the availability of the reserve margin states, or else availability and frequency data for generating capacity states, not considering the load. The method presented and illustrated may be extended t o consider the calculation of operating reliability or the inclusion of the effects of a simple transmission system.
Copolymerization of Chlorocyclotriphosphazene Derivatives Containing the Methacycloylbutenedioxy and N-(Ferrocenylmethyl)-N-Methylamino Substituents with Methylmethacrylate

The mixed substituent chlorocyclophosphazene monomers 2,2′-N3P3Cl4[O(CH2)4OC(O)C(Me)CH2][C5H5FeC5H4CH2NMe](1) and 2,2′,4-N3P3Cl3[O(CH2)4OC(O)C(Me)CH2][C5H5FeC5 H4CH 2NMe]2 (2) undergo radical addition copolymerization with methylmethacrylate to produce a broad range of copolymers having pendant cyclophosphazenes containing a ferrocenyl substitutent. In both bulk and solution copolymerization, the conversion decreased with increasing amount of 1 in the monomer feed with no copolymer formation observed in co-monomer mixtures containing greater than 50% of 1. NMR studies of the copolymers show that the copolymer composition is the same as the monomer feed and that the triad tacticity is constant throughout the series for 1 but an increase in syndiotactic triads is observed for 2. TGA studies indicate an increase in char yield with an increase in the phosphazene content of the copolymer.
The effect of phosphoenolypyruvate on calcium transport by mitochondria

Abstract Phosphoenolpyruvate was found to inhibit net uptake of Ca 2+ by rat heart and liver mitochondria. The main action of phosphoenolpyruvate is to increase the rate of efflux of mitochondrial Ca 2+ . The effect of phosphoenolpyruvate on mitochondrial Ca 2+ transport is antagonized by ATP and by atractylate and is observed when mitochondria are respiring in the presence of NAD-linked subtrates such as glutamate and pyruvate plus malate. In liver mitochondria phosphoenolpyruvate is also effective in the presence of succinate but not when rotenone is added. Glycolytic intermdiates other than phosphoenolpyruvate had little effect on mitochondrial Ca 2+ transport.
Polymeric Gene Delivery for Diabetic Treatment

Several polymers were used to delivery genes to diabetic animals. Polyaminobutyl glycolic acid was utilized to deliver IL-10 plasmid DNA to prevent autoimmune insulitis of non-obese diabetic (NOD) mouse. Polyethylene glycol grafted polylysine was combined with antisense glutamic acid decarboxylase (GAD) MRNA to represent GAD autoantigene expression. GLP1 and TSTA (SP-EX4) were delivered by bioreducible polymer to stop diabetic progression. Fas siRNA delivery was carried out to treat diabetic NOD mice animal.
Bridging the Missing Link of Cloud Data Storage Security in AWS

The data that is stored and/or transmitted on the Internet has been called "the blood of the IT". Along with the infrastructure and network based applications, data storage has been recognized as one of the major dimensions of information technology. The prosperity of Cloud Computing requires the moving from server-attached storage to distributed storage. Along with variant advantages, the distributed storage also poses new challenges in creating a secure and reliable data storage and access facility over insecure or unreliable service providers. The security of data stored in the cloud is one of the challenges to be addressed before the novel pay-as-you-go business model is applied widely. In this research, we revealed the vulnerability in the Amazon's A WS cloud and discussed technical approaches towards potential effective solutions.
Leukocytes synthesize angiotensinogen.

To determine whether leukocytes express the angiotensinogen gene, we subjected circulating rat leukocytes and murine bone marrow cells to Northern blot analysis and hybridization with homologous angiotensinogen complementary DNA. Angiotensinogen messenger RNA sequences were detected in circulating adult rat leukocytes, in murine-irradiated and nonirradiated bone marrow stromal cells, and in an adherent stromal cell line (preadipocyte). Western blot analysis of rat leukocyte homogenate showed that rat leukocytes contain two main angiotensinogen isoforms with approximate molecular weights of 46.5 and 53.9 kd. Synthesis and release of angiotensinogen protein by rat leukocytes was confirmed by immunoprecipitation of radiolabeled angiotensinogen from cell lysate and media of rat leukocytes that were metabolically labeled with 35S-L-methionine. In addition, the angiotensinogen protein present in media of rat leukocytes was enzymatically cleaved by hog renin, resulting in generation of angiotensin I (305 +/- 47 pg angiotensin I per milliliter of media per hour). We conclude that circulating rat leukocytes express the angiotensinogen gene and synthesize and release angiotensinogen with the capability to generate angiotensin. Expression of angiotensinogen by leukocytes may provide a mobile angiotensin-generating system of potential importance in the regulation of local inflammatory responses, tissue injury (i.e., myocardial infarction), and arterial hypertension.
The Ideology of the United Nations Charter and the Philosophy of Peace of Immanuel Kant 1795-1945

1945-the year which witnessed the final rout of the forces of Fascist and National Socialist reaction in Europe, and the drafting of a Charter for a new world of United Nations1945 is also the 150th anniversary of the appearance of Immanuel Kant's Essay on Eternal Peace. The wizened little man with the giant mind, so provincial in his personal life as never to have left his native city of K6nigsberg, so universal in his sympathy as to feel himself a fellow of the American and French revolutionaries, hammered out in his seventy-first year a brief discourse of prophetic insight. He sought to show and to prove as best he could that peace, eternal, universal peace, was not only desirable, (that had been done by many others before him), was not only conceivable, (that too had been done repeatedly), but was necessary and inevitable. Clothed in the quaint and involved eighteenth century German which was just emerging from medieval Latin, the short Essay is nevertheless as inspired as anything Kant wrote. And far from being a marginal by-product of his old age, this little treatise flowed from the very core of Kant's feeling. It develops more fully ideas which crop up again and again in other places in his writings on ethics and social philosophy. It rests squarely upon Kant's extraordinary philosophy of history. What is more, looking back from San Francisco in 1945 we can test his ideas by the intervening century and a half,
Preventative Counseling for the Gifted Adolescent: From Words to Action.

A reliable preventive counseling program is one that recognizes the distinct affective needs of the gifted adolescent and one that becomes an integral part of the curriculum.
Subcellular distribution of ‘intersecting’ β-N-acetylglucosaminyltransferase in Dictyostelium discoideum. A likely marker for the Golgi apparatus

Abstract Glycoprotein processing in Dictyostelium discoideum is characterized by enzyme catalyzed steps not reported in other organisms. One of these is the formation of a β 1 → 4 linkage between GlcNAc and the mannose linked to the core mannose in the α 1 → 6 position of N-glycosides. A simple and sensitive assay for this GlcNAc transferase activity, using a tri-mannose acceptor and a low concentration of UDP-G1cNAc, was developed. Homogenates of the organism were subjected to sub-cellular fractionation by centrifugation in discontinuous sucrose gradients. The specific activity was enriched 4–5-fold in a crude membrane fraction. The transferase was purified 10–12-fold in a membrane fraction that bands on top of 1.1 M sucrose. This fraction was also enriched in nucleotidyldiphosphatase. The enriched fraction was deficient in glucose-6-phosphatase, an endoplasmic reticulum marker. Approx. 80% of the transferase activity was latent, and unavailable to protease. Purified membranes were either subjected to phase separation in Triton X-114, or sodium carbonate extraction or sonication. In each case, the transferase behaved as an intrinsic membrane protein. Several secreted and lysosomal proteins are modified by the enzyme. These data support the idea that the GlcNAc transferase is present an an integral Golgi membrane protein and that at least the catalytic center of the transferase is on the lumenal side of the vesicles.
Three problems in applying contestability to regulated markets

The theory of contestable markets emphasizes that the ease of entry rather than the number of existing firms forces incumbents to set prices at optimal levels. The policy implications of this work contrast sharply with past U.S. regulatory and antitrust policies, legitimizing increased industry concentration and decreased regulation. This paper explores three factors that influence the desirability of regulation or antitrust policy despite the apparent existence of a contestable market time lags, technological change, and cyclical macroeconomic fluctuations. Time lags enable incumbents to earnsupra-normal profits and take last-minute action to forestall entry. New technologies can create sunk costs that reduce the contestability of a market. Recessions can depress capital markets, raising the cost of exit, while expansion creates opportunities for entry without threatening monopolistic prices. These shortcomings limi the ability of contestability theory to provide guidelines for the regulation of actual industries.
Allosteric modulation of the 5-HT3 receptor

5-Hydroxytryptamine type 3 (5-HT3) receptors are ligand-gated ion channels that play important roles in depression, anxiety, substance abuse, emesis, inflammatory pain, spinal nociception, gastrointestinal function, and cardiovascular reflexes. Probably the most studied modulators of 5-HT3 receptors are the high affinity competitive ‘setron’ antagonists typified by ondansetron. However, there exists a broad range of compounds that modulate the 5-HT3 receptor, not through the orthosteric site but by binding to allosteric sites. Most notable are therapeutic compounds ascribed to certain targets but that allosterically modulate 5-HT3 receptors at clinically relevant concentrations.
Continuous administration of dopamine alters cellular immunity in chickens

Abstract Dopamine administered continuously through osmotic pumps altered the PHA wattle response and in vitro leukocyte capillary tube migration in UNH 105 chickens. The PHA wattle response was suppressed significantly by 48 hr exposure to dopamine at a dose of 1 μg/hr. Administration of 10 μg/hr dopamine for 48 hr enhanced significantly in vitro leukocyte migration.
The effect of the composition of butterfat on its susceptibility of oxidation

There is considerable variation in the stability of the butter fat toward oxidation where it is obtained from different cows and from an individual cow at different periods.
Quantitation of interference in digoxin immunoassay in renal, hepatic, and diabetic disease

A comparison of the results of a newly developed fluorescence-derivatization/HPLC method and a commercial immunoassay method (ACA, Dupont) for the measurement of serum digoxin concentrations in patients indicates that (1) the results from the ACA method agree well with those from the HPLC method in patients with cardiovascular disease but without renal, diabetic, and liver disease, (2) serum digoxin concentrations determined by the ACA method are overestimated in patients with renal, diabetic, or liver disease, and (3) the steady-state serum concentrations of hydrolyzed and reduced metabolites are relatively insignificant in patients receiving digoxin therapy, including patients with renal failure. The excellent reproducibility of the HPLC and immunoassay methods (coefficient of variation < 9.0%), together with the demonstrated specificity of the HPLC method with respect to potential interference from digoxin metabolites, endogenous digoxin-like immunoactive substances, and coadministered drugs and their metabolites, allows quantitation of the degree of interference in digoxin immunoassays under actual therapeutic drug monitoring conditions. Clinically significant interferences (0.3 to 1.1 ng/ml) with immunoassay determination were found in the majority of patients in all three diseases studied. Clinical Pharmacology & Therapeutics (1997) 61, 429–441; doi:
Angular distribution of charming B → VV decays and time evolution effects

Angular distributions of a B meson decaying into two vector mesons are discussed with emphasis on time evolution effects on the complete set of amplitude bilinears. Time integrated quantities are suggested to observe substantial $\mathrm{CP}$ violation in decays with charm quarks in the final state particles. Relations among the nine observables at $t=0$ are found to be useful for a consistency check of experimentally extracted quantities. Numerical estimates of the nine observables are made using form factor models and the assumption of the factorization hypothesis. Branching ratio asymmetries for ${B}_{u}^{+}\ensuremath{\rightarrow}{D}^{*+}{D}^{*0}$ and ${B}_{d}\ensuremath{\rightarrow}{D}^{*+}{D}^{*\ensuremath{-}}$ can be as large as $\ensuremath{-}3%$ and $\ensuremath{-}4%,$ respectively.
The antigenicity of synthetic peptide fragments of lactate dehydrogenase C4.

Lactate dehydrogenase C4 (LDH-C4) is an antigenic protein found only in spermatozoa and the mature testis. Synthetic peptides containing the amino acid sequences of the C-subunit, designated MC5–15, MC97–110 and MC211–220, were each conjugated to the carrier proteins diphtheria toxoid or bovine serum albumin. Rabbits immunized with these peptide-carrier conjugates produced antibodies to the peptide that cross-reacted with native LDH-C4. These data support our map that identifies antigenic domains of LDH-C4. Such synthetic peptides will be useful in the design of a contraceptive vaccine.
Hierarchical, modular discrete-event modelling in an object-oriented environment

Hierarchical, modular specification of discrete-event models of fers a basis for reusable model bases and hence for enhanced simulation of truly varied design alternatives. We describe an envi ronment which realizes the DEVS formalism developed in Zeigler 1984 for hierarchical, modular models. It is implemented in PC-Scheme, a powerful Lisp dialect for microcomputers contain ing an object-oriented programming subsystem. Since both the implementation and the underlying language are accessible to the user, the result is a capable medium for combining simula tion modelling and artificial intelligence techniques. The envi ronment is developed in an object-oriented manner which lends itself to model base organization using the entity structure knowl edge representation. It also serves as a medium for developing hierarchical distributed simulation models and architectures.
Rapid in vivo inactivation by acivicin of CTP synthetase, carbamoyl-phosphate synthetase II, and amidophosphoribosyltransferase in hepatoma.

Abstract A single injection of the anti-glutamine drug, acivicin (NSC 163501), in tumor-bearing rats in 30 min decreased the activities of amidophosphoribosyltransferase, carbamoyl-phosphate synthetase II and CTP synthetase to 56, 50 and 7% of those of the controls. By 1 hr the activities were down to 32, 13 and 3% and they remained low for 12 hr, after which they slowly returned towards normal range in 72 hr. The decline of the activity of CTP synthetase (a loss of 80% in 10 min) was the most rapid, and the activity only returned to 60% of the controls by 3 days after the acivicin injection. In the hepatoma the concentrations of ATP and UTP changed little, but those of GTP and CTP rapidly decreased, reaching at the lowest point 32 and 2%, respectively, of control values 2 hr after acivicin; concentrations started to rise at 12 hr, reaching normal levels by 48 hr. The drop in enzyme activities preceded the decline in the pools of GTP and CTP. The behavior of enzyme activities and nucleotide concentrations in the host liver had a pattern similar to that in the hepatoma; however, the changes were less extensive than those in the tumor. The differential response between tumor and liver is attributed, in part at least, to the tissue L-glutamine concentration which in the hepatoma (0.5 mM) was 9 times lower than in the liver (4.5 mM). The selectivity of acivicin action in inhibiting glutamine-utilizing enzymes is also demonstrated by the lack of effect on aspartate carbamoyltransferase, a an enzymic activity which resides in the same complex as that of carbamoyl-phosphate synthetase II. The rapid decline in the activities of glutamine-utilizing enzymes is attributed to an in-activation of the enzymes by acivicin which functions as an active site-directed affinity analog of L-glutamine. The rapid modulation of the enzymic phenotype and ribonucleotide concentrations by acivicin provides a useful tool for elucidating the role of enzymic and nucleotide imbalance in the commitment of cancer cells to replication and in the targeting of anticancer chemotherapy.
Leveraging interferometric metrology for precision manufacturing

Commercial interferometers can be both quite accurate and easy to use. Advanced surface specifications and manufacturing techniques, however, require a greater awareness of gauge capabilities. We discuss how to critically analyze metrology for such situations.
Flows along penumbral flux tubes in sunspots. Instability of super-Alfvénic, serpentine solutions

The super-Alfvenic, undulating "sea-serpent" flow configurations along thin magnetic flux tubes, proposed by Schlichenmaier (2002, Astron. Nachr., 323, 303; 2003, ASP Conf. Ser., 286, 24) to explain both the Evershed flow and mov- ing penumbral grains in a sunspot, are shown to be gravitationally unstable. Any undulations that occur for super-Alfvenic flow speeds will form preferentially in a horizontal plane and hence will not explain Evershed downflows or outward-moving penumbral grains. Sub-Alfvenic, arched flow configurations, on the other hand, are gravitationally stable.
Stratiform precipitation in regions of convection : A meteorological paradox ?

It was once generally thought that stratiform precipitation was something occurring primarily, if not exclusively, in middle latitudes—in baroclinic cyclones and fronts. Early radar observations in the Tropics, however, showed large radar echoes composed of convective rain alongside stratiform precipitation, with the stratiform echoes covering great areas and accounting for a large portion of the tropical rainfall. These observations seemed paradoxical, since stratiform precipitation should not have been occurring in the Tropics, where baroclinic cyclones do not occur. Instead it was falling from convection-generated clouds, generally thought to be too violent to be compatible with the layered, gently settling behavior of stratiform precipitation. In meteorology, convection is a dynamic concept; specifically, it is the rapid, efficient, vigorous overturning of the atmosphere required to neutralize an unstable vertical distribution of moist static energy. Most clouds in the Tropics are convection-generated...
Efficacy of the First Step to Success Intervention for Students with Attention-Deficit/Hyperactivity Disorder

This study evaluated the efficacy of the First Step to Success early intervention for students meeting criteria for attention-deficit/hyperactivity disorder (ADHD). First Step is a targeted intervention for students in grades K-3 with externalizing behavior problems, and addresses secondary prevention goals and objectives. As part of a larger randomized controlled trial conducted within the Albuquerque Public School system, the efficacy of the First Step program was evaluated on a subsample of 42 students meeting DSM-IV criteria for ADHD who were randomly assigned to either the intervention group or a usual care control group. The First Step program was found to have significant and moderate-to-large post-intervention effects on school-based measures of ADHD and disruptive behavior symptoms, social functioning, and academic functioning. The intervention effects on the home-based assessments of problem behaviors and social skills were less robust and nonsignificant. Implications and limitations of the study are discussed.
Enhanced leptin transport across the blood–brain barrier by α1-adrenergic agents

Leptin is a 16 kDa protein secreted by fat cells which regulates body weight and thermogenesis at sites within the brain. Blood-borne leptin reaches those brain sites because of a saturable transport system located at the blood-brain barrier (BBB). Impaired transport occurs in obese rodents and likely underlies the resistance to the actions of peripheral leptin seen in obesity. Here, we show that leptin transport into the brain is enhanced 2-3-fold by epinephrine and other agents which are more specific for the alpha1 adrenergic receptor. Epinephrine had no effect on the transport across the BBB of insulin or tumor necrosis factor, on BBB integrity, or on the size of the vascular space of the brain. Dopamine, acetylcholine, histamine, serotonin, thyroid hormones, and phentolamine were without effect. Of several amino acids tested, only the catecholamine precursor tyrosine had an effect on leptin transport. Epinephrine was effective after intravenous or intraperitoneal injection, but neither epinephrine nor any of the other monoamines given by intracerebroventricular injection had an effect on leptin transport. These results show that epinephrine likely acts at a site on the luminal surface of the BBB. In conclusion, epinephrine works at an alpha1-like adrenergic, luminal side to enhance the transport of leptin across the BBB.
The Birth of Neutron Stars and Black Holes

Neutron stars are nothing if not exotic. Most are the residues of massive stars that, after exhausting their thermonuclear fuel, die spectacularly as supernovae. Fifty percent more massive than our Sun, but only 20 kilometers in diameter, they are the densest objects in the universe. At the surface of a neutron star, the acceleration due to gravity is in excess of 1011 times that at the surface of Earth, so that the binding energy of a parcel of matter in a neutron star is about 10% of its rest mass. Hence mass accretion onto a neutron star, which releases over 100 MeV/nucleon, is a far more efficient energy conversion process than thermonuclear fusion, which releases approximately 8 MeV/nucleon. Theory suggests that neutron stars are about 95% neutrons in “chemical” equilibrium with a small admixture of protons and electrons: n⇄p++e−. Some investigators have likened a neutron star to a giant nucleus with atomic mass about 1057. The pressure of strongly interacting degenerate neutrons at supranuclear densities is balanced by gravity to maintain a hydrostatic equilibrium in the canonical configuration described above. Neutron stars therefore are laboratories for both nuclear physics and general relativity.
Heat transfer in a round tube with sinusoidal wall heat flux distribution

Sufficiently accurate values of first twenty eigenvalues, eigenfunctions Rn (1), and the coefficients for series expansion, as well as asymptotic expressions for these quantities, have been obtained for heat (or mass) transfer to fully developed laminar flow inside a round tube with uniform wall heat (or mass) flux. The first ten eigenfunctions are shown graphically for the radius range 0 ≤ r/ro ≤ 1. These quantities are used to calculate the Nusselt numbers for sinusoidal wall heat flux distribution and are compared with the corresponding slug flow Nusselt numbers.
Heterogeneous effects of calorie restriction on in vivo glucose uptake and insulin signaling of individual rat skeletal muscles.

Calorie restriction (CR) (consuming ∼60% of ad libitum, AL, intake) improves whole body insulin sensitivity and enhances insulin-stimulated glucose uptake by isolated skeletal muscles. However, little is known about CR-effects on in vivo glucose uptake and insulin signaling in muscle. Accordingly, 9-month-old male AL and CR (initiated when 3-months-old) Fischer 344xBrown Norway rats were studied using a euglycemic-hyperinsulinemic clamp with plasma insulin elevated to a similar level (∼140 µU/ml) in each diet group. Glucose uptake (assessed by infusion of [14C]-2-deoxyglucose, 2-DG), phosphorylation of key insulin signaling proteins (insulin receptor, Akt and Akt substrate of 160kDa, AS160), abundance of GLUT4 and hexokinase proteins, and muscle fiber type composition (myosin heavy chain, MHC, isoform percentages) were determined in four predominantly fast-twitch (epitrochlearis, gastrocnemius, tibialis anterior, plantaris) and two predominantly slow-twitch (soleus, adductor longus) muscles. CR did not result in greater GLUT4 or hexokinase abundance in any of the muscles, and there were no significant diet-related effects on percentages of MHC isoforms. Glucose infusion was greater for CR versus AL rats (P<0.05) concomitant with significantly (P<0.05) elevated 2-DG uptake in 3 of the 4 fast-twitch muscles (epitrochlearis, gastrocnemius, tibialis anterior), without a significant diet-effect on 2-DG uptake by the plantaris or either slow-twitch muscle. Each of the muscles with a CR-related increase in 2-DG uptake was also characterized by significant (P<0.05) increases in phosphorylation of both Akt and AS160. Among the 3 muscles without a CR-related increase in glucose uptake, only the soleus had significant (P<0.05) CR-related increases in Akt and AS160 phosphorylation. The current data revealed that CR leads to greater whole body glucose disposal in part attributable to elevated in vivo insulin-stimulated glucose uptake by fast-twitch muscles. The results also demonstrated that CR does not uniformly enhance either insulin signaling or insulin-stimulated glucose uptake in all muscles in vivo.
Lessons from an interdisciplinary system dynamics course

System dynamics has long held a promise of solving social problems. Such efforts benefit from interdisciplinary teams that can combine strong technical skills for modeling and analysis with people skills for working with stakeholders and understanding the substantive issues of social problems. In this note we describe a joint graduate system dynamics course between social work and electrical and systems engineering that emphasizes students learning how to develop and work in interdisciplinary teams to address social problems. We discuss the advantages of such teams, some of the challenges, and share lessons from the experience. Copyright © 2009 John Wiley & Sons, Ltd.
Modeling film dynamics in spray impingement

A numerical and analytic study of film formation and evolution during spray impingement is presented. For the part of the film which excludes drop impact locations, the governing equations reduce to a convenient form that can be exploited using a Lagrangian particle method. At impingement points the source terms for mass and energy are calculated based on conservation principles and phenomenological results. It is shown that during the period where most of the film evolution takes place, the effect of gas shear and surface tension are negligible. Numerical testing is performed to ensure convergence
An asymptotic study of the inductive pattern formation mechanism in Drosophila egg development

The complexity and nonlinear dynamics of patterning networks in development make modeling an important approach for the evaluation of the experimentally derived pattern formation mechanisms. As a rule, mechanistic models of patterning networks have large number of uncertain parameters; model analysis requires extensive computational searches of the parameter space. Analytical techniques can circumvent these difficulties and offer important insights into the networks’ functional capabilities. Here, we present an asymptotic analysis of the multiple steady states and transitions between them in a mechanistic model of patterning events specifying the formation of a pair organ in Drosophila oogenesis. The model describes the interaction between the spatially nonuniform inductive signal and a network of spatially distributed feedback loops. Our approach dramatically reduces the complexity of the problem and provides an explicit analytical method for the construction and parametric analysis of the patterned states responsible for signaling. The analysis reveals a skeleton structure for the patterning capability of the considered regulatory module and demonstrates how a single regulatory network can be used to generate a variety of developmental patterns.
Parenting Practices of Anxious and Nonanxious Mothers: A Multi-Method, Multi-Informant Approach

Anxious and nonanxious mothers were compared on theoretically derived parenting and family environment variables (i.e., overcontrol, warmth, criticism, anxious modeling) using multiple informants and methods. Mother-child dyads completed questionnaires about parenting and were observed during an interactional task. Findings reveal that, after controlling for race and child anxiety, maternal anxiety was associated with less warmth and more anxious modeling based on maternal-report. However, maternal anxiety was not related to any parenting domain based on child-report or independent observer (IO) ratings. Findings are discussed in the context of the impact of maternal anxiety on parenting and suggest that child, rather than maternal, anxiety may have a greater influence on maternal behavior.
In simple synthetic promoters YY1-induced DNA bending is important in transcription activation and repression

Depending on promoter context, YY1 can activate or repress transcription, or provide a site for transcription initiation. To investigate whether the ability of YY1 to induce DNA bending influenced its ability to activate and repress transcription, simple synthetic promoters were constructed in which the YY1 binding site was inserted between the TATA box and either the NF1 or AP1 recognition sequences. In transient transfections of COS cells, the NF1YY1TATA and NF1RYY1TATA promoters exhibited a dramatic 15-20-fold increase in correctly initiated transcription. These promoters exhibited even larger 60-80-fold increases in transcription in HeLa cells. Neither multiple copies of the YY1 binding site alone, nor placement of a YY1 site upstream of the NF1 site activated transcription. Deletion of 4 bp between the NF1 and YY1 sites, which changes the phase of the DNA bends, abolished the 16-fold activation of transcription by NF1YY1TATA. Insertion of the YY1 site between the AP1 site and the TATA box decreased transcription approximately 3-fold. Replacing the YY1 binding site with an intrinsic DNA bending sequence mimicked this transcription repression. Sequences of similar length which do not bend DNA fail to repress AP1-mediated transcription. Gel mobility shift assays were used to show that binding of YY1 to its recognition sequence did not repress binding of AP1 to its recognition sequences. Our data indicate that YY1-induced DNA bending may activate and repress transcription by changing the spatial relationships between transcription activators and components of the basal transcription apparatus.