cssi/SciSciGPT-SciSciNet huggingface dataset:
TU-C-103-09: CT Model-Based Iterative Reconstruction: How Much Dose Can We Save?

Purpose: To determine the potential for dose reduction with adaptive statistical iterative reconstruction (ASiR) and model‐based iterative reconstruction (MBIR) as compared to conventional filtered back‐projection (FBP) reconstruction methods. Methods: The low‐contrast module of a Catphan 600 phantom was scanned using a GE Discovery HD750, at 120 kVp, 0.8 second rotation time, and pitch factors of 0.516, 0.984 and 1.375. The mA was selected for each of the three pitch factors to achieve CTDIvol values of 24, 18, 12, 6, 3, 2 and 1 mGy. Images were reconstructed at 2.5mm thickness with FBP; 20%, 40% and 70% ASiR; and MBIR. The 1% contrast, 15mm diameter supra‐slice object and adjacent background were selected to determine the noise and CNR. To minimize statistical variations in noise, for each scan condition, images from 10 independent acquisitions were analyzed. The results were confirmed in the anthropomorphic Kyoto Kagaku abdomen phantom at 6, 3, 2 and 1 mGy. Results: Compared to FBP, MBIR considerably reduced noise and improved CNR at all dose levels. At low doses in particular, a five‐fold decrease in noise and four‐fold increase in CNR were observed. ASiR also improved image quality compared to FBP across the range of dose values investigated, but to a lesser degree than MBIR. At 70% ASiR, up to a two‐fold increase in CNR and 50% noise reduction were achieved. The quantitative results over 3 different pitch factors were similar. By maintaining image quality at the level of 1 mGy, dose reduction was estimated for MBIR and ASiR compared to FBP. Up to 97% dose saving was achieved with MBIR and up to 15% for ASiR (70%). Conclusion: Both MBIR and ASiR maintained image quality at substantially reduced dose levels as compared to FBP. MBIR demonstrated the feasibility for low‐dose patient imaging at sub‐mGy dose levels.
A metric for continuous quality evaluation of compressed video with severe distortions

Abstract An objective quality metric that generates continuous estimates of perceived quality for low bit rate video is introduced. The metric is based on a multichannel model of the human visual system. The vision model is initially parameterized to threshold data and then further optimized using video frames containing severe distortions. The proposed metric also discards processing of the finest scales to reduce computational complexity, which also results in an improvement in the accuracy of prediction for the sequences under consideration. A temporal pooling method suited to modeling continuous time waveforms is also introduced. The metric is parameterized and evaluated using the results of a Single Stimulus Continuous Quality Evaluation test conducted for CIF video at rates from 100 to 800 kbps . The proposed metric exceeds the performance of a similar metric based on the Mean Squared Error.
Administrative Challenge or Ethical Dilemma? Responding Justly When a Student With a Disability Engages in a Violent or Disruptive Act:

This case study involves an 8-year-old American Indian student with a disability, who was videotaped assaulting another student as they exited the school bus. Although acts of school violence are common on campuses across the nation, this incident is particularly complex, given the disability status of the student committing this act. This case provides an opportunity for both practicing and aspiring school leaders to explore a number of administrative and ethical dilemmas related to the discipline of students with disabilities and other special educational needs, utilizing a framework grounded in principles of social justice and equity.
MENISCUS ADHESION AT ULTRA-LOW FLYING SLIDER-DISK INTERFACES

As head-disk spacings in disk drives approach a few nanometers, adhesive forces between the slider and disk can drastically alter the slider flying dynamics. At these small separations, it is still unclear, however, what type of adhesive force dominates. Most previous studies have concentrated on van der Waals and electrostatic attractive forces [1], which are readily incorporated into air bearing simulations. In this talk, we provide experimental evidence that the dominant adhesive force originates from menisci forming around the low flying portions of the slider air-bearing-surface as the spacing transitions from near-contact to contact.Copyright © 2005 by ASME
An Algorithm for Facility Location in a Districted Region

The problem of facility siting in a districted region is discussed and a two-stage algorithm proposed. The first stage consists of solving a particular facility siting problem (for example, a p-median problem, or a maximal location covering problem) in each district for all possible allocations of facilities to a district with respect to the number of facilities allocated in each district. The second stage is the allocation of resources (facilities) among the districts. A greedy algorithm is proposed to solve the resource allocation problem with a criterion of minimizing the sum of weighted distances under convex conditions.
The Political Economy of Information: The Impact of Transborder Data Flows

Developments in communication technology as change agents in international relations have been given little more than passing reference in much of the international studies literature. Such advances, however, and especially the most recent developments, are believed by these authors to be critical factors in changing and shaping the world system. The authors isolated transborder data flows to illustrate the overall impact of technological developments, and examined the technology itself, and its political and economic role in the world system. Specifically discussed are the relationships between multinational corporations and states, the information policies of governments, and the current and potential ramifications of transborder data flows technology on policy making. Finally, the authors make recommendations for policy makers on three levels: international, regional, and national. Specifically recommended are: 1) increased involvement of international organizations; 2) establishment of an international mechanism for the cooperative management of transborder data flows; 3) regional cooperation to employ transborder data flows in development and trade; 4) increased awareness on the part of developing nations of the impacts of transborder data flows on economic and political development; 5) concrete and cooperative national policy to ward off international tension and disharmony over transborder data flows and direct them toward facilitating world peace and development.
School refusal behavior in young children.

School refusal behavior is defined as any child-motivated refusal to attend classes and/or difficulty remaining in classes for an entire day. Although many researchers have focused on older children and adolescents in their samples, few have specifically focused on young children aged 5-9 years (i.e., kindergarten to third grade). In this article, a general description is made of school refusal behavior, and illustrative data from 55 young children with school refusal behavior are provided. Recommendations for assessing and treating this young population are made as well.
Epigenetic silencing of host cell defense genes enhances intracellular survival of the rickettsial pathogen Anaplasma phagocytophilum.

Intracellular bacteria have evolved mechanisms that promote survival within hostile host environments, often resulting in functional dysregulation and disease. Using the Anaplasma phagocytophilum–infected granulocyte model, we establish a link between host chromatin modifications, defense gene transcription and intracellular bacterial infection. Infection of THP-1 cells with A. phagocytophilum led to silencing of host defense gene expression. Histone deacetylase 1 (HDAC1) expression, activity and binding to the defense gene promoters significantly increased during infection, which resulted in decreased histone H3 acetylation in infected cells. HDAC1 overexpression enhanced infection, whereas pharmacologic and siRNA HDAC1 inhibition significantly decreased bacterial load. HDAC2 does not seem to be involved, since HDAC2 silencing by siRNA had no effect on A. phagocytophilum intracellular propagation. These data indicate that HDAC up-regulation and epigenetic silencing of host cell defense genes is required for A. phagocytophilum infection. Bacterial epigenetic regulation of host cell gene transcription could be a general mechanism that enhances intracellular pathogen survival while altering cell function and promoting disease.
Pitfalls for testbed evaluations of internet systems

Today's open platforms for network measurement and distributed system research, which we collectively refer to as testbeds in this article, provide opportunities for controllable experimentation and evaluations of systems at the scale of hundreds or thousands of hosts. In this article, we identify several issues with extending results from such platforms to Internet wide perspectives. Specifically, we try to quantify the level of inaccuracy and incompleteness of testbed results when applied to the context of a large-scale peer-to-peer (P2P) system. Based on our results, we emphasize the importance of measurements in the appropriate environment when evaluating Internet-scale systems.
Androgen metabolism by mature rabbit epididymal tissue: The effects of castration and androgen replacement

Abstract Castration of adult rabbits leads to a rapid decline in the ability of the epididymis to metabolize androgens. Castrated rabbits were injected with testosterone propionate (T.P.) (2 mg/kg/day) to determine if androgen administration would result in the maintenance of epididymal 4-ene-3-ketosteroid 5α-reductase and 5α-androstane-3α(3β)-hydroxysteroid dehydrogenase. These enzymes are required for the conversion of testosterone to 5α-dihydrotestosterone (5α-DHT) and 5α-DHT to 5α-androstane-3α-17β-diol (3α-diol), respectively. This dose of T.P. resulted in plasma levels of testosterone that were 5–7 fold higher than and in epididymal levels of testosterone that were similar to non-treated intact rabbits. When epididymal minces from T.P.-treated castrated rabbits were incubated with 8.25 × 10 −9 M [ 3 H]-testosterone for 2 h at 0°C, followed by l h at 23°C, analysis of metabolites formed indicated that the post-castration induced decline in 5α-DHT production did not occur and the 3α-diol synthesis was slightly elevated. However, when epididymal minces were incubated with [ 3 H]-testosterone at 32°C for 2h, there was a 3-fold increase in both 5α-DHT and 3α-diol formation as compared to the above incubation conditions. Castration resulted in an 80% decrease in the amount of 5α-DHT produced. Although androgen replacement failed to maintain 5α-DHT synthesis at control levels, the amount of 5α-DHT synthesized was twice that of castrated non-treated rabbits. There was no apparent effect on the amount of [ 3 H]-testosterone that was converted to 3α-diol. When epididymal minces were incubated with [ 3 H]-5α-DHT for 2 h at 32°C, 3α-diol formation was significantly greater ( P 3 H]-testosterone. Castration leads to a 50% decline in 3α-diol synthesis. Androgen replacement resulted in a significant stimulation ( P
UME6, a negative regulator of meiosis in saccharomyces cerevisiae, contains a C‐terminal Zn2Cys6 binuclear cluster that binds the URS1 DNA sequence in a zinc‐dependent manner

UME6 is a protein of 836 amino acids from Saccharomyces cerevisiae that acts as a repressor and activator of several early meiotic genes. UME6 contains, near the C-terminus, the amino acid sequence-771C-X2-C-X6-C-X6-C-X2-C-X6-C-, in which the spacings of the six Cys residues are identical to those found in 39 N-terminal Cys-rich DNA binding subdomains of fungal transcription factors. This sequence has been shown in GAL4 and other proteins to form a zinc binuclear cluster. In spite of the different location, the C-rich sequence, cloned and over-produced within the last 111 amino acid residues of UME6, UME6(111), forms a binuclear cluster and exhibits a Zn-dependent binding to the URS1 DNA sequence. The latter, TAGCCGCCGA, is required for the repression or activation of meiosis-specific genes by UME6. UME6(111) contains 1.8 +/- 0.4 mol Zn/mol protein and the Zn can be exchanged for Cd to yield a protein containing 1.9 +/- 0.1 mol Cd/mol protein. At 5 degrees C, 113Cd2UME6(111) shows two 113Cd NMR signals, with chemical shifts of 699 and 689 ppm, similar to those observed for 113Cd2GAL4(149). The magnitude of these chemical shifts suggests that each 113Cd nucleus is coordinated to four -S- ligands, compatible with a 113Cd2 cluster structure in which two thiolates from bridging ligands. The entire UME6 gene has been cloned and overexpressed and binds more tightly to the URS1 sequence than the zinc binuclear cluster domain alone. DNase I footprints of UME6 on URS1-containing DNA show that the protein protects the phosphodiesters of the 5'-CCGCCG-3' region within the URS1 sequence.
Flight assessment of three flat-panel display technologies

Flight assessment of three flat-panel display technologiesEllis F. HillBattelle, National Security Division505 King Avenue, Columbus, OH 43201ABSTRACTFlat panel display technologies which could replace obsolete airborne cathode ray tubes (CRTs)are still in the development stage and not available as mass produced items. Flight andlaboratory assessments were conducted on three technologies: Active Matrix Liquid CrystalDisplay (AMLCD), AC Gas Plasma Display (ACGPD), and Thin Film Electroluminescent (TFEL).1. INTRODUCTIONMilitarized I 0 inch monochrome Cathode Ray Tube (CRT) display units are used in the B-52(ASQ-1 51 and ASQ-1 75) and B-I B (ASQ-I 84) to display real-time video from steerable television(STV), forward looking infrared (FLIR), and radar sensors, as well as graphics/text in a stand-alone or a video overlay presentation. These 25-30 year old CRT displays are becomingunsupportable due to the obsolesence ofthe technology in these units. The number of U.S.sources for replacement CRT tubes is very limited. Advances in flat panel display technologiesmake them likely candidates to replace the obsolete CRT display units. The performancecharacteristics of the candidate flat panel display technologies must meet or exceed those givenin Table I forthe CRTs to be replaced.Table I . Specified Characteristics of the CRT Display UnitsActive Area: 8 inches (horizontal) by 6 inches (vertical)Luminance: Not Specified (Measured as 160 ft.)Contrast:
Clinical estimation of the volumes of blood in the right heart, left heart, and lungs by use of I131 albumin☆☆☆

Abstract 1. 1. An external isotope method for estimating intracardiac and pulmonary blood volumes has been studied in 41 subjects with and without cardiac disease. 2. 2. Intracardiac blood volume estimated from radioactivity of the cardiac area 10 minutes after intravenous injection of 100 μc of I131 albumin averaged 345 ± 55 ml./M.2 in 16 subjects without heart disease. 3. 3. In general, intracardiac blood volume was proportional to the size of the heart shadow; but there was slightly less blood in relation to the size of the heart in subjects with cardiac hypertrophy. In 2 persons with pericardial effusion the intracardiac blood volumes were approximately 500 ml. less than would have been expected from the size of the cardiac shadow, suggesting an area of diagnostic usefulness for this technique. 4. 4. By dividing the curve of precordial radioactivity during the first circulation of the isotope into the right and left heart components, the portion of the intracardiac blood in each side of the heart and the pulmonary blood volume were estimated. 5. 5. The right heart volume in subjects without heart disease was 170 ± 25 ml./M.2, and the left heart volume was 185 ± 50 ml./M.2. 6. 6. In normal subjects, pulmonary blood volume was 490 ± 130 ml./M.2. Similar results were obtained in subjects with mitral stensos and with other forms of heart disease. 7. 7. The isotope methods used in the present studies contain important technical defects. Accurate and reliable techniques will require further development of instrumentation and procedure.
Simulation of network activity in stomatogastric ganglion of the spiny lobster, panulirus

Abstract We have compared experimental and model studies on the rhythmic activity of the lobster stomatogastric ganglion. Both the pyloric and gastric mill systems were simulated using a physiologically based network model. In the pyloric simulation the known synaptic connectivity of the 3 principal cell types in the pyloric rhythm was found to be sufficient to produce the correct sequence of cyclic bursting activity over a substantial range of parameter values, even though we did not simulate the known endogenous oscillatory driver potential of one of the cell types. It is not yet known whether the synaptic inhibition in the real system is in the right range to cause cyclic bursting in the absence of the driver potential, but the synaptic connectivity does appear to reinforce the cyclic pattern. Simulations were also done with alternative connectivity schemes to determine which synapses appear essential to generate the correct bursting sequence (in the absence of endogenous bursting activity). Other, more complex, systems simulated were: (1) all 5 cell groups of the pyloric system, and (2) the cells responsible for movement of the lateral teeth in the gastric mill. In both cases good qualitative agreement was achieved between model and real systems.
High School Students Attitudes about and Recommendations for Their Peers with Significant Disabilities

The present study addresses the impact that placement and service models have had on nondisabled high school student attitudes. Negative attitudes have been a frequently identified barrier to parti...
Spill-to-spill and daily proton energy consistency with a new accelerator control system.

The Loma Linda University proton accelerator has had several upgrades installed including synchrotron dipole power supplies and a system for monitoring the beam energy. The consistency of the energy from spill-to-spill has been tested by measuring the depth ionization at the distal edge as a function of time. These measurements were made with a minimally equipped beamline to reduce interference from confounding factors. The consistency of the energy over several months was measured in a treatment room beamline using an ionization chamber based daily quality assurance device. The results showed that the energy of protons delivered from the accelerator (in terms of water equivalent range) was consistent from spill-to-spill to better than {+-}0.03 mm at 70, 155, and 250 MeV and that the energy check performed each day in the treatment room over a several month period was within {+-}0.11 mm ({+-}0.06 MeV) at 149 MeV. These results are within the tolerances required for the energy stacking technique.
Cavitation characteristics of a small centrifugal pump in He I and He II

The cavitation characteristics of a small preinduced centrifugal pump operating in He I and He II over the temperature range 1.8-4.2 K are presented. The pump and close-coupled induction motor operate immersed in liquid helium. A six-blade propeller inducer and a three-blade screw inducer were both tested. With this pump configuration using either inducer, there is a tremendous difference between the cavitation characteristics of He I and He II. The net positive suction head requirements for this pump with the screw inducer could not be determined for He I, but it is less than -100 mm and, depending on flow rate, ranges between 35 and 165 mm for He II.
Dual Allosteric Inhibitors Exhibit Antagonistic Effects in the Hepatitis C Virus Polymerase

The Hepatitis C Virus (HCV) affects close to 200 million people globally. This growing epidemic urgently requires the development of more effective therapies. The HCV polymerase (gene product NS5B) has served as a valuable target for therapeutics due to its critical role in replicating the viral genome. Numerous studies have identified inhibitors for this enzyme, including several allosteric non-nucleoside inhibitors (NNIs). A therapeutic approach that has gained prominence in recent years is the combined use of multiple inhibitors in order to enhance their inhibitory effects. Nevertheless, the molecular mechanisms responsible for enhanced inhibition of NS5B when multiple inhibitors are involved remain unclear, particularly with regard to NNIs. In this study, we use molecular dynamics simulations to understand the mechanisms that govern inhibition when two allosteric NNIs simultaneously bind to the HCV polymerase. Our results suggest that NS5B is able to simultaneously bind dual NNIs at non-overlapping sites. Even though the two inhibitors induce distinct structural and dynamic changes, they are also able to jointly modulate specific enzyme conformations and dynamics. We observe that the overall affinity when two inhibitors bind is comparable to the sum of individual affinities, suggesting that these inhibitors act in an additive manner. We discuss the ramifications of these findings for optimizing the efficacies of combination therapies targeting the HCV polymerase.
Monte Carlo simulation of supercritical solutions in the grand canonical ensemble

Abstract Molecular simulations have been undertaken of pure, repulsive, and attractive supercritical Lennard-Jones solutions using the Monte Carlo technique in the grand canonical ensemble for the same systems and states used in a previous study by the molecular dynamics technique in the canonical ensemble. The pure supercritical fluid exhibited structure which differed somewhat between the canonical and grand canonical simulations at distances of more than three or four diameters from a central particle. The grand canonical simulation was shown to have chemical potential in agreement with the calculations from the equation of state and to be thermodynamically consistent. Simulations of the repulsive mixture in the grand canonical ensemble were characterized by substantial statistical scatter so that the special capabilities of the grand canonical simulation - fluctuation analysis and thermodynamic consistency testing — could not be employed. The attractive supercritical mixture studied previously was found to be within the two-phase region when studied in the grand canonical ensemble. The only previous simulation of mixtures in the grand canonical ensemble did not attempt to apply the fluctuation analysis or the thermodynamic consistency test; so, the negative results of this work are new.
Specificity of gene action during central nervous system development in Drosophila melanogaster: Analysis of the lethal (1) optic ganglion reduced locus

Abstract A newly defined genetic locus designated lethal (1) optic ganglion reduced (l(1)ogre: 1–18.8, 6E 1 2 – 6E 4 5 ) is characterized. Four alleles have been isolated, one organismal viable and three organismal lethals. Histological analyses of these mutants at the light microscopic level have detected defects only in the developing and adult central nervous system (CNS). Examination of genetic mosaics suggests that the wild-type product of this locus may function specifically in the CNS. Analyses of staged material show that abnormalities first become apparent early in the larval period, indicating that the l(1)ogre+ gene product normally acts at or before this stage. No maternal effects were detectable. Determination of the temperature-sensitive period for lethality, of a temperature-sensitive heteroallelic combination, indicates that the l(1)ogre+ gene product also acts late in the larval period. These results show that the time of l(1)ogre+ gene action overlaps the period during which growth and assembly of the imaginal CNS occurs and are consistent with the hypothesis that l(1)ogre may act specifically in the imaginal CNS during its morphogenesis.
THE CHILD IN THE CITY: A RESEARCH AGENDA

Children are an important part of urban life. Although the birthrate is declining, there are still a large number of children living in cities. But we have devoted little effort to designing our ci...
Poisson Ensembles in Three Dimensions

The authors recently derived a method for assessing stochastic randomness in three dimensional Euclidean space. The method was derived from a nearest neighbor spatial Poisson process. An alternativ...
Magnitude of negative reinforcement and resistance to extinction

Abstract In the first experiment rats experienced large or small magnitude of negative reinforcement (shock reduction) in a straight alley. Half of the subjects in each magnitude group received continuous reinforcement, and the other half received a 50% partial reinforcement schedule (nonreinforcement consisting of no shock reduction in the goal box). In extinction the groups were ordered: large partial > small-partial > small-continuous > large-continuous. In the second experiment rats received large, small and nonreinforcement in various sequences using the runway-negative reinforcement procedure and were ordered: SNL>LNL>SNL>LNS in resistance to extinction (letters represent the magnitudes in the sequence experienced in acquisition). The results of these experiments indicate a commality between positive and negative reinforcement with respect to behavioral phenomena and theoretical accounts of those phenomena.
Transcription in human fibroblasts permissively infected by human cytomegalovirus strain AD169.

Abstract We used cloned subgenomic DNA fragments of human cytomegalovirus strain AD169 as hybridization reagents to analyze the sites of transcription and abundance of viral RNA in permissively infected human embryonic lung cells. RNA extracted from immediate early, early, middle, and late times in the infection was attached to filters and hybridized with excess cloned subgenomic fragments. Each hybridization was performed with an internal standard to allow quantitation of the RNA concentration and standardization for the variation in probe complexity and specific activity. We found immediate early transcription in the AD169 strain occurring primarily from three regions in the long unique segment at 0.061–0.110, 0.117–0.142, and 0.588–0.616 map units. A low level of transcription was also detected from the long unique segment at 0.230–0.372, 0.419–0.437 and 0.703–0.707 map units and the short unique segment and terminal repeats at 0.00–0.046, 0.776–0.854, and 0.892–1.00 map units. At 8 hr after infection in the presence of de novo protein synthesis, the transcription pattern was changed. Two of the major immediate early sites at 0.061–0.110 and 0.117–0.142 map units were represented less abundantly in the absence of cycloheximide while the site at 0.588–0.616 map units was represented at the same level. The most abundant early RNA was synthesized from the terminal repeat sequences and part of the short unique segment at 0.00–0.046, 0.776–0.822, and 0.892–1.00 map units. Steady-state RNA from the midpoint of the infection hybridized with most regions of the genome. Abundantly transcribed regions included the abundant early sites mentioned above (0.00–0.046, 0.588–0.616, 0.776–0.822, and 0.892–1.00 map units), several new sites in the long unique segment at 0.104–0.110, 0.576–0.588, 0.653–0.664, 0.703–0.707, and 0.766–0.776 map units and the L-S junction fragment at 0.804–0.854 map unit. RNA from late in the infection hybridized to all subgenomic fragments. The sites of de novo RNA synthesis along the genome were determined by hybridizing pulse-labeled RNA to individual cloned subgenomic fragments attached to filters. Transcription from the terminal repeat sequences and the long unique segment at 0.576–0.588 map unit accounted for 40% of the total viral RNA synthesized from 22 to 28 hr after infection. Of the total de novo RNA synthesis from 71 to 77 hr after infection, 4.3% was virus specific and 47% of the total de novo synthesized viral RNA hybridized to the terminal repeat sequences.
The Role of the Mucosal Barrier in Drug- Induced Gastric Ulceration and Erosions

There are seven drugs usually stated to be ulcerogenic in man and at least one general textbook of medicine implicates a number of them (1). These drugs are adrenal corticosteroids, aspirin, phenylbutazone, indomethacin, ethanol, caffeine, and tobacco (smoking). The types of data upon which these conclusions are based follow three lines of evidence. First, the ability of these drugs to produce experimental ulcers or erosions; all of these drugs can cause ulcers when given to animals (2-7). Second, a cause-andeffect relationship in man, ie, epidemiological evidence; the epidemiological evidence is very weak except for aspirin and smoking. Third, a mechanism suspected of participating in the pathogenesis; the pathogenesis of drug ulceration is not fully understood but aspirin may be the only one with a body of data to support its ulcerogenic effect. The purpose of this paper is to examine the epidemiological evidence as well as possible mechanisms by which drugs may be associated with gastric damage. Reviews of various aspects of this subject have been published in the past few years (8-12). Thus, attention will be mainly directed to certain aspects of the literature.
Collisional quenching and radiative decay of the mercury excimer

Abstract We have measured the molecular continuum radiation from Hg2* in the 4000–5000 A range; the excitation was produced by a high energy, short pulse electron beam. When the excimer concentration is large, the dominant loss process is biexcimer collisional deactivation. At lower concentrations the decay becomes exponential and a radiative lifetime of the continuum radiation of 14 ± 3 μsec is measured.
Interaction between phencyclidine (PCP) and Gaba-ergic drugs: Clinical implications

Pretreatment (IP) of mice with (-) baclofen, muscimol, 4,5,6,7-tetrahydroisoxazolo (S,4-c) pyridin-3-ol hydrate (THIP), aminooxyacetic acid (AOAA) or gamma-acetylenic GABA caused a dose-dependent inhibition of thelocomotor stimulant effect of phencyclidine (PCP, 8 mg/kg). Although (-) baclofen was found to be the most effective PCP antagonist, its (+) isomer was inactive. The maximum blocking effect of AOAA was seen in animals treated 3 and 6 hr earlier. Except for gamma-acetylenic GABA, none of these drugs significantly blocked the locomotor stimulant effect of d-amphetamine (3 mg/kg, IP). Diazepam reduced d-amphetamine response, but failed to influence PCP-induced stimulation. The locomotor stimulant effect of PCP, unlike that of d-amphetamine, may be the result of a specific GABA antagonistic effect at certain dopamine-rich areas of the brain. It seems that (-) baclofen may prove to be useful in the management of PCP intoxication. Administration of higher doses of PCP (20 and 50 mg/kg) in mice pretreated with (-) baclofen resulted in the development of surgical anesthesia manifested as the loss of a) righting reflex, b) pain sensation and c) corneal reflex. The duration of the general anesthetic response was found to be a function of the doses of both (-) baclofen and PCP. The possible use of (-) baclofen as an adjuvant to general anesthetic is discussed.
Correction and extension of Broberg's results on brittle crack propagation

Abstract The solution to the problem posed by Broberg is deduced as a special case of the problem of a line crack with ends moving at different speeds. This latter problem is solved using the similarity method recently developed by the author. The generality of the method allows for a unified treatment and extension of several problems which have been considered individually by other authors. The similarity method is used in conjunction with the techniques introduced by Muskhelishvili for static elasticity and is proposed as an alternative to the Wiener-Hopf method.
Monoclonal antibodies for coagglutination of Streptococcus suis type 1.

Abstract Monoclonal antibodies (MAbs) were sought that would identify Streptococcus suis . Spleen cells from Balb/c mice immunized with formalin-killed S. suis were fused with the murine cell-line SP-2/0. Hybridomas positive for S. suis were identified by a solid-phase radioimmunoassay with a mixture of all available serotypes of S. suis . On further screening with individual serotypes of S. suis (Types 1,2,1/2,3,4,5,7,8,9 and 12) and other related and unrelated bacteria, a hybridoma specific for Type 1 was identified. Another hybridoma was positive for all serotypes of S. suis. S. suis Type 1-specific MAbs in the form of ascites fluid was used in a coagglutination test. Agglutination with S. suis Type 1 was observed within 45 s, while there was no reaction with other serotypes of S. suis or other bacteria, during the 5-min observation period. A library of type-specific MAbs should help in rapid and accurate serotyping of S. suis isolates.
A comparative study of system response time on program developer productivity

Skilled programmer time and computer time and resources are valuable. Earlier studies had shown that added computer resources can decrease system response time and increase programmer productivity significantly. A controlled study has been made to determine whether that finding is true for the particular conditions in another program development organization. That study is reported here. Programmer productivity increased sixty-two percent with subsecond system response time. A new finding is that individual group project offices lead to greater efficiency than large open rooms.
Relating fine root biomass to soil and climate conditions in the Pacific Northwest

Abstract The additive contribution of fine root biomass for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) to the stand average fine root biomass were estimated for eight conifer stands in the Pacific Northwest. Based on the Ribbens model fits to root coring data and the size and location of trees in the conifer stands, the estimated stand-level fine root biomass was 188–1157 g m−2 for P. menziesii and 24–347 g m−2 for T. heterophylla. Site differences in the stand-level fine root biomass for P. menziesii and T. heterophylla were largely explained by climate and soil nitrogen. Fine root biomass for P. menziesii was inversely related to soil nitrogen and, to a lesser extent, annual precipitation and temperature. These relationships were unchanged when data from our sites and four studies in the published literature were combined. In comparison, fine root biomass for T. heterophylla was positively related to temperature and precipitation and, to a lesser extent, inversely related to soil nitrogen. Because temperature and precipitation have opposite effects on fine root biomass for P. menziesii and T. heterophylla, these climate variables were not important predictor variables for total fine root biomass. In addition, the inverse relationship between total fine root biomass and soil nitrogen was obscured and confounded by the root–climate–species interaction.
Evaluation and modification of spectrophotometric procedures for analysis of lactate dehydrogenase, beta-glucuronidase and arylsulphatase in human gingival crevicular fluid collected with filter-paper strips.

Abstract Filter-paper strips were used to collect GCF, and the sample eluted into a larger volume of diluent. This procedure allows for detection of site-to-site variation in GCF volume, and provides a 300–400 μl sample for analysis of lactate dehydrogenase (LDH), beta-glucuronidase (BG) and aryl-sulphatase (AS) activities by a standard (serum) spectrophotometric assay modified for increased sensitivity. The results indicate that although the standard assay for LDH (based on oxidation of NADH) was adequate for detecting low activity in GCF samples, the modification doubled the sensitivity and allowed the use of less sample volume, thereby providing additional material for other assays. The standard assay for BG based on phenolphthalein being generated from phenophthalein glucuronic acid was not adequate for use in GCF analysis. The modification used increased assay sensitivity five-fold and allowed smaller samples to be used. The serum assay for AS (conversion of nitrocatechol sulphate to nitrocatechol) was accurate to the lower limit of AS activity in GCF and could be used without modification. The results emphasize the need to evaluate critically standard spectrophotometric assays for sensitivity when studying physiologically-collected GCF.
ADOPTION OF INNOVATIONS FROM APPLIED BEHAVIORAL RESEARCH: “DOES ANYBODY CARE?”

Applied behavioral researchers develop useful innovative technologies experimentally, and yet few of these technologies enjoy widespread adoption by our society. This paper analyzes several instances in which government agencies adopted behavioral technology, identifies 10 manipulable variables that could increase the rate of adoption of such technological innovations, and relates them to the field of knowledge diffusion. Unifying theory and experimental analysis are lacking in that field, yet an implicit technology may exist.
Immunotoxin therapy of leptomeningeal neoplasia

Malignant tumors of the central nervous system can result from metastatic dissemination of a variety of cancers. Percutaneous intracisternal injection of an anti-idiotype monoclonal antibody (M6) ricin immunotoxin was shown to be moderately effective in prolonging the survival of tumor bearing animals supporting the use of immunotoxins for the treatment of central nervous system neoplasia (Zovickian J and Youle R.J.J. Neurosurg 68: 767, 1988). This report describes a method that significantly improves the survival of immunotoxin treated Strain 2 guinea pigs in a syngeneic animal model of leptomeningeal neoplasia. Strain 2 guinea pigs, implanted with subarachnoid catheters, received three courses of treatment with an (M6)-intract ricin immunotoxin following intracisternal inoculation of L2C leukemia tumor cells. Animals were treated with three to four micrograms of immunotoxin in three divided doses. This was found to be less toxic and more effective than single bolus administration of immunotoxin. These results demonstrate that a permanent indwelling catheter in this animal model facilitates multiple dose delivery of immunotoxin therapy allowing the assessment of various treatment schedules and the achievement of enhanced therapeutic effect. Furthermore, these results support the continued evaluation of immunotoxins for the treatment of central nervous system neoplasia.
Alcohol effects on γ-aminobutyric acid type A receptors: are extrasynaptic receptors the answer?

GABA(A) receptors have long been implicated in mediating at least part of the actions of ethanol in mammalian brain. However, until very recently, reports of the actions of EtOH on recombinant receptors have required very high doses of ethanol and animals lacking receptor subunits shown to be important for ethanol actions in vitro did not support the view that these subunits are crucial in ethanol actions. Recombinant alpha4beta3delta and alpha6beta3delta GABA(A) receptors are uniquely sensitive to ethanol, with a dose-response relationship mirroring the well known effects of alcohol consumption on the human brain. Receptors containing the delta subunit are thought to be located extrasynaptically and it will be important to determine if these extrasynaptic GABA(A) receptor subunit combinations mediate low dose alcohol effects in vivo.
On-chip process variation monitoring circuit based on gate leakage sensing

A novel on-chip process-variation monitoring circuit for nanoscale CMOS designs is proposed. The proposed circuit can monitor both global and local variations associated with transistors on an integrated circuit. The process variation is monitored by gate-tunnelling-leakage sensing with weak temperature dependence, which solves the problem of the strong temperature dependence of the conventional subthreshold leakage sensing. The proposed circuit with low power dissipation (1.92 µW at 85°C) is implemented using 45 nm technology, and the results show that it monitors only the process variation with weak dependence (within 5%) on VDD and temperature variations.
A Short-Range Optical Transmission System for Television Signals

The paper describes the design of an infrared transmitter and receiver for communication over 1000 feet typical distance. The purpo.se of the system was to circumvent obstacles in the construction of the closed circuit television systems, and it has been successfully used for that purpose in a number of applications. The authors show calculation of path characteristics which determine fade margin requirements and the level of path dependent noise. They describe experimental verification of the calculations on a 1021-foot test path. Part of the paper describes the pertinent characteristics of the Gallium Arsenide Transmitter diode and the receiver photodiode, especially with respect to bandwidth and linearity. The optical system design is described in detail, including tolerances on the aiming system and the mechanical support of the diodes. Some of the measurement_ techniques developed to insure performance of manufactured systems are described, including techniques for power measurement and alignment.
Thiol-derivatized minihepcidins retain biological activity

Minihepcidins are small peptides that mimic biological activity of the iron-regulatory hormone hepcidin. Structurally, they contain thiol-free-cysteine residue in position 7 which is crucial for their bioactivity. Nonetheless, free sulfhydryl group is not desirable in pharmaceutical entities as it may lead to dermatological side effects. Moreover free thiol moiety is quite reactive and depending on conditions/reagents may be alkylated and/or oxidized giving various Cys-derivatives: S-alkyl cysteines, sulfoxides, sulfones, disulfides, cysteinesulfinic and cysteic acids. To limit such reactivity and maintain bioactivity of minihepcidin(s) we used thiol-protection strategy based on activated vinyl thioethers. Novel S-protected analogs of physiologically active minihepcidin PR73 were synthesized and tested in vitro showing activity comparable to parental molecule. The most active compound, PR73SH was also tested in vivo showing activity profile analogous to PR73. Collectively, our findings suggest that S-vinyl-derivatization of minihepcidin(s) may be a suitable approach in the development of physiologically active agonists of hepcidin.
High Purity Germanium for Detector Fabrication

The preparation of large (100) oriented germanium crystals with net concentrations of electrically active impurities in the range 1-10 × 1010cm-3 is described. This material has been used successfully for the fabrication of semiconductor detectors having depletion layers up to 8 mm thick, without using lithium compensation. Electrical evaluation is performed by studying the Hall coefficient as a function of temperature, and by measuring the resistivity along the length at 77°K. Dislocation densities in most crystals range from 2000 to 5000 cm-2 Several dislocation-free crystals have also been grown. The oxygen concentration, measured by lithium precipitation, is approximately 1014 cm-3 in germanium grown from quartz crucibles and much less than this when grown from graphite. The solubility of lithium in pure, oxygen-free germanium is found to be 3.5 × 1013cm-3 at 23°C.
Histone H3 Ser10 phosphorylation-independent function of Snf1 and Reg1 proteins rescues a gcn5- mutant in HIS3 expression

Gcn5 protein is a prototypical histone acetyltransferase that controls transcription of multiple yeast genes. To identify molecular functions that act downstream of or in parallel with Gcn5 protein, we screened for suppressors that rescue the transcriptional defects of HIS3 caused by a catalytically inactive mutant Gcn5, the E173H mutant. One bypass of Gcn5 requirement gene (BGR) suppressor was mapped to the REG1 locus that encodes a semidominant mutant truncated after amino acid 740. Reg1(1-740) protein does not rescue the complete knockout of GCN5, nor does it suppress other gcn5− defects, including the inability to utilize nonglucose carbon sources. Reg1(1-740) enhances HIS3 transcription while HIS3 promoter remains hypoacetylated, indicating that a noncatalytic function of Gcn5 is targeted by this suppressor protein. Reg1 protein is a major regulator of Snf1 kinase that phosphorylates Ser10 of histone H3. However, whereas Snf1 protein is important for HIS3 expression, replacing Ser10 of H3 with alanine or glutamate neither attenuates nor augments the BGR phenotypes. Overproduction of Snf1 protein also preferentially rescues the E173H allele. Biochemically, both Snf1 and Reg1(1-740) proteins copurify with Gcn5 protein. Snf1 can phosphorylate recombinant Gcn5 in vitro. Together, these data suggest that Reg1 and Snf1 proteins function in an H3 phosphorylation-independent pathway that also involves a noncatalytic role played by Gcn5 protein.
Adaptive hidden Markov models for extended landmine detection

Previous experiments with Hidden Markov Models showed that they could be used as an algorithm for landmine detection. In this paper we propose a basic adaptive algorithm for discrete Hidden Markov Model for landmine detection. The performance of adaptive HMM is investigated using GPR data from gathered during the Vehicle Mounted Mine Detection Advanced Technology Demonstrations. In both cases the adaptive HMM outperforms the baseline HMM model, trained offline using Baum-Welch algorithm.
Conformational effects of selected cancer-related amino acid substitutions in the p53 protein.

Abstract The tumor suppressor gene p53 has been identified as the most frequent target of genetic alterations in human cancers. Cancer-related mutations in the human p53 protein tend to cluster in four of the five highly conserved domains of the protein, and, in particular, in the central region of domain IV from residues 241 to 253. Using conformational energy analysis based on ECEPP (Empirical Conformational Energies for Polypeptides Program), we have determined the preferred three dimensional structures for this tridecapeptide sequence for the human wild-type p53 protein and four cancer-related mutant p53 proteins (Ala 245, Ile 246, Trp 248, Ser249). The results show that the mutant peptides adopt conformations that are distinctly different from that of the wild-type peptide. These results are consistent with experimental conformational studies demonstrating altered detectability of antigenic epitopes in murine wild-type and mutant p53 proteins. These results suggest that the oncogenic effects of human...
Toxic Alexandrium peruvianum (Balech and de Mendiola) Balech and Tangen in Narragansett Bay, Rhode Island (USA)

Abstract Phytoplankton monitoring in Wickford Cove, Rhode Island, US (41°34′10.13″N, 71°26′45.76″W), located in Narragansett Bay, detected an unusual species of Alexandrium in the spring of 2009. Thecal plate analysis using brightfield and SEM microscopy revealed a plate morphology consistent with that of Alexandrium peruvianum (Balech and de Mendiola) Balech and Tangen. Molecular analyses indicated that the sequences of the SSU, ITS1, 5.8S, ITS2 and LSU through the D region of the 18S gene were similar to those of A. peruvianum from North Carolina. Toxin analyses of cells brought into culture revealed saxitoxins, gymnodimine and fast-acting spiroimines were present in the cultured clone. Saxitoxins detected included GTX 2, GTX3, B1, STX, C1 and C2. Also present in the Wickford cove isolates of A. peruvianum were 12-methyl gymnodimine and 13-desmethyl spirolide C. A. peruvianum was detected at four sites in lower Narragansett Bay: at two sites in Wickford and two sites in Jamestown, RI. A. peruvianum was observed in the spring of 2009, 2010, 2011 and 2012 at maximum abundance levels ranging from tens of cells per liter to 14,000 cells L −1 . The discovery of A. peruvianum in Rhode Island coastal waters, with its potential threat to public health, is notable as it appears to be an emergent bloom species globally. The presence of A. peruvianum in Narragansett Bay is the third confirmed observation of this species on the Atlantic coast of North America. Monitoring efforts in the southern New England region should incorporate measures to detect the presence of A. peruvianum toxins.