cssi/SciSciGPT-SciSciNet huggingface dataset:
Radiation Induced Soft Fails in Space Electronics

Advanced microelectronic circuits are sensitive to the passage of single ionizing particles. These circuits store information so that the deposition of a small charge (picocoulomb range) can charge a storage node, resulting in a bit error. This effect presents a problem to computer memories on earth because alpha particles are emitted from microelectronic packages and materials. The problem is much more severe in space due to primary cosmic rays and to nuclear reactions in the device produced by protons from the earth's radiation belts. A number of satellite systems have been severely affected by single event soft-fails.
Use of pharmacy refill data as a measure of antiretroviral adherence

Pharmacy refill adherence has become an increasingly important measure of adherence to antiretroviral medications. It offers a simple, inexpensive, and valid method for measuring adherence. Over the past year, there have been several published developments in the use of pharmacy refill data to measure adherence. Given the utility of this adherence measurement, it is likely that pharmacy refill will be the method of choice for measuring antiretroviral adherence in an increasing number of clinical and research settings.
Complete structure of the gene for human keratin 18.

Abstract The complete sequence of the human keratin 18 (K18) gene was determined. The K18 gene is 3791 bp in length and the K18 protein is coded for by seven exons. The exon structure of K18 has been conserved compared to that of other keratin genes, with the exception of a single 3′ terminal exon that codes for the tail domain of the protein that is represented by two exons in epidermal keratins. The K18 gene contains an unusual AG GC donor splice site of intron 3 instead of the consensus AG GT sequence. This variation is not seen in any other intermediate filament genes. The promoter region of the gene contains a TATA box, six potential SP1 binding sites, and 10 copies of CACCC boxes but lacks any CCAAT boxes and is surprisingly different from the immediately 5′ flanking region of the homologous mouse Endo B gene. However, both genes contain small CpG islands surrounding the 5′ end of exon 1 and, in addition, conserve repetitive Alu potential transcription units approximatelly 300 nt upntream of the transcriptional start site.
Structural and magnetic behavior of vapor quenched Fe-Mo alloys

Abstract Magnetic ordering temperatures ( T C ) of Fe x Mo 100- x alloys over the entire composition range and magnetic properties at the boundary separating the crystalline and the amorphous phases have been studied. The T C of the crystalline bcc alloys shows a percolation threshold at x ≈20, and T C rises with Fe content towards that of pure Fe. Large differences have been observed in the magnetic moment and T C between amorphous and bcc alloys.
Student Expectancies and Academic Self-Concept as Predictors of Science Achievement

(1996). Student Expectancies and Academic Self-Concept as Predictors of Science Achievement. The Journal of Psychology: Vol. 130, No. 6, pp. 679-681.
Hypoxia-Ischemia in Newborn Piglets Causes Early Changes in the Expression and Localization of the GLAST Glutamate Transporter Protein Within Striatum† 1890

Hypoxia-Ischemia in Newborn Piglets Causes Early Changes in the Expression and Localization of the GLAST Glutamate Transporter Protein Within Striatum† 1890
Individual-based predator-prey model for biological coevolution: fluctuations, stability, and community structure.

We study an individual-based predator-prey model of biological coevolution, using linear stability analysis and large-scale kinetic Monte Carlo simulations. The model exhibits approximate $1∕f$ noise in diversity and population-size fluctuations, and it generates a sequence of quasisteady communities in the form of simple food webs. These communities are quite resilient toward the loss of one or a few species, which is reflected in different power-law exponents for the durations of communities and the lifetimes of species. The exponent for the former is near $\ensuremath{-}1$, while the latter is close to $\ensuremath{-}2$. Statistical characteristics of the evolving communities, including degree (predator and prey) distributions and proportions of basal, intermediate, and top species, compare reasonably with data for real food webs.
r-process nucleosynthesis in dynamic helium-burning environments

The results of an extended examination of r-process nucleosynthesis in helium-burning enviroments are presented. Using newly calculated nuclear rates, dynamical r-process calculations have been made of thermal runaways in helium cores typical of low-mass stars and in the helium zones of stars undergoing supernova explosions. These calculations show that, for a sufficient flux of neutrons produced by the C-13 neutron source, r-process nuclei in solar proportions can be produced. The conditions required for r-process production are found to be 10 to the 20th-10 to the 21st neutrons per cubic centimeter for times of 0.01-0.1 s and neutron number densities in excess of 10 to the 19th per cubic centimeter for times of about 1 s. The amount of C-13 required is found to be exceedingly high - larger than is found to occur in any current stellar evolutionary model. It is thus unlikely that these helium-burning environments are responsible for producing the bulk of the r-process elements seen in the solar system.
Innate immune responses to transplants: a significant variable with cadaver donors.

This work was supported in part by National Institutes of Health Grants AI42387 and HL56091 (W. M. B.); DK50762, AI40519, and AR42687 (C. P. L.); and AI 40459 and AHA 0050538N (R. L. F.).
Implications of wind-assisted aerial navigation for Titan mission planning and science exploration

The recent Titan Saturn System Mission (TSSM) proposal incorporates a montgolfiere (hot air balloon) as part of its architecture. Standard montgolfiere balloons generate lift through heating of the atmospheric gases inside the envelope, and use a vent valve for altitude control. A Titan aerobot (robotic aerial vehicle) would have to use radioisotope thermoelectric generators (RTGs) for electric power, and the excess heat generated can be used to provide thermal lift for a montgolfiere. A hybrid montgolfiere design could have propellers mounted on the gondola to generate horizontal thrust; in spite of the unfavorable aerodynamic drag caused by the shape of the balloon, a limited amount of lateral controllability could be achieved. In planning an aerial mission at Titan, it is extremely important to assess how the moon-wide wind field can be used to extend the navigation capabilities of an aerobot and thereby enhance the scientific return of the mission. In this paper we explore what guidance, navigation and control capabilities can be achieved by a vehicle that uses the Titan wind field. The control planning approach is based on passive wind field riding. The aerobot would use vertical control to select wind layers that would lead it towards a predefined science target, adding horizontal propulsion if available. The work presented in this paper is based on aerodynamic models that characterize balloon performance at Titan, and on TitanWRF (Weather Research and Forecasting), a model that incorporates heat convection, circulation, radiation, Titan haze properties, Saturn's tidal forcing, and other planetary phenomena. Our results show that a simple unpropelled montgolfiere without horizontal actuation will be able to reach a broad array of science targets within the constraints of the wind field. The study also indicates that even a small amount of horizontal thrust allows the balloon to reach any area of interest on Titan, and to do so in a fraction of the time needed by the unpropelled balloon. The results show that using the Titan wind field allows an aerobot to significantly extend its scientific reach, and that a montgolfiere (unpropelled or propelled) is a highly desirable architecture that can very significantly enhance the scientific return of a future Titan mission.
Patterns in the recall of persons in a student community

Abstract This paper reports on the patterns in the recall of persons in a contemporary, socially bounded community. The associative, serial order, and frequency response patterns in the free recall of persons' names among students in a graduate academic program were found to be based on the program's cohort structure. Several observations on patterns in the recall of persons' names in this community paralleled findings from research on the recall of lexical items. The results suggested that individual informants' different positions in the cohort structure produced systematic variation in social knowledge of fellow students.
Photo-Mapping for Microscopically Controlled Surgery

Photo-mapping with a Polaroid system can increase the precision of micro-controlled surgery in certain cases. The systems available and our method are described.
Chemical Analysis with a Low-Resolution Raman Spectrometer

The performance of a very compact and low-cost Raman system has been examined in detail. We have attempted to use it for both qualitative identifications and quantitative analyses of mixtures. As a part of the evaluation, we have attempted to devise compensation routines when these were needed. We conclude that this system can be used for a limited range of qualitative applications, but that the quantitative performance is inadequate. The principal problems originated in laser fluctuations and in the appearance of spectral artifacts when the laser was operated.
Research Skill Needs and Research Environment of Allied Health Faculty: Implications for Continuing Education.

Faculty members in academic allied health units have less scholarly output than educators from other fields. Administrators, especially those in major research institutions, are searching for ways to improve research records of their faculty. A survey was conducted to identify the research skill needs and characteristics of the research environment of four allied health programs traditionally housed in baccalaureate degree programs. Questionnaires were received from 1028 physical therapy, dietetics, medical technology, and occupational therapy educators. Most educators indicated a lack of sufficient skills in grantsmanship, obtaining funding, and statistical analysis of data. Many faculty also needed help to develop research designs, write proposals, identify research problems, collect data, and write papers for publication. Wide variability was observed in research environments. A majority of faculty reported having a personal interest in research and recognized its importance for academic advancement. Less than one-fourth of respondents said they had financial and administrative support for research, and many felt uncertain about the relative importance of research versus teaching and service. Creative continuing education opportunities are needed to better prepare faculty for independent research.
Hoechst 33258 fluorescent staining of Drosophila chromosomes.

Metaphase chromosomes of D. melanogaster, D. virilis and D. eohydei were sequentially stained with quinacrine, 33258 Hoechst and Giemsa and photographed after each step. Hoechst stained chromosomes fluoresced much brighter and with different banding patterns than quinacrine stained ones. In contrast to mammalian chromosomes, Drosophila's quinacrine and Hoechst bright bands are all in centric heterochromatin and the banding patterns seem more taxonomically divergent than external morphological characteristics. Hoechst stained D. melanogaster chromosomes show unprecedented longitudinal differentiation in the heterochromatic regions; each arm of each autosome can be unambiguously identified and the Y shows eleven bright bands. The Hoechst stained Y can also be identified in polytene chromocenters. Centric alpha heterochromatin of each D. virilis autosome is composed of two blocks which can be differentiated by a combination of quinacrine and Hoechst staining. The distal block is always Q−H− while the proximal block is, for the various autosomes, either Q−H−, Q+H− or Q+H+. With these permutations of Hoechst and quinacrine staining, D. virilis autosomes can be unambiguously distinguished. The X and two autosomes have H+ heterochromatin which can easily be seen in polytene and interphase nuclei where it seems to aggregate and exclude H− heterochromatin. This affinity of fluorochrome similar heterochromatin was best seen in colcemid induced multiple somatic non-disjunctions where H+ chromosomes were distributed to one rosette and H− chromosomes were distributed to another. Knowing the base composition and base sequences of Drosophila satellites, we conclude that AT richness may be a necessary but is certainly an insufficient requirement for quinacrine bright chromatin while GC richness may be a sufficient requirement for the absence of quinacrine or Hoechst brightness. Condensed euchromatin is almost as bright as Q+ heterochromatin. While chromatin condensation has little effect on Hoechst staining, it appears to be “the most important factor responsible for quinacrine brightness”. All existing data from D. virilis indicate that each fluorochrome distinct block of alpha heterochromatin may contain a single DNA molecule which is one heptanucleotide repeated two million times.
Generation of dynamic temporal and spatial concentration gradients using microfluidic devices.

This paper describes a microfluidic approach to generate dynamic temporal and spatial concentration gradients using a single microfluidic device. Compared to a previously described method that produced a single fixed gradient shape for each device, this approach combines a simple “mixer module” with gradient generating network to control and manipulate a number of different gradient shapes. The gradient profile is determined by the configuration of fluidic inputs as well as the design of microchannel network. By controlling the relative flow rates of the fluidic inputs using separate syringe pumps, the resulting composition of the inlets that feed the gradient generator can be dynamically controlled to generate temporal and spatial gradients. To demonstrate the concept and illustrate this approach, examples of devices that generate (1) temporal gradients of homogeneous concentrations, (2) linear gradients with dynamically controlled slope, baseline, and direction, and (3) nonlinear gradients with controlled nonlinearity are shown and their limitations are described.
Macrocycle complexation chemistry 32. Modification of the lanthanide ion coordination sphere via electrocrystallization of hydrated lanthanide chloride complexes of 12-Crown-4

Abstract Electrochemical techniques have been utilized to modify the crystallization of 12-crown-4 complexes of PrCl 3 · n H 2 O from CH 3 CN:CH 3 OH (3:1) solutions. [PrCl 3 (OH 2 )(12-crown-4)]·12-crown-4 crystallized from a 10:1 (12-crown-4:Pr) solution in the centric space group Pnma , with a = 23.338(7), b = 13.103(5), c = 7.713(4) A and D calc = 1.74 g cm −3 for Z = 4. [PrCl 3 (OHMe)(12-crown-4)] crystallized in the centric P 1 , with a = 7.486(3), b = 9.365(4), c = 11.268(4) A, α = 91.92(3), β = 93.87- (3), γ = 102.00(3)° and D calc = 1.96 g cm −3 for Z = 2. Both complexes differ markedly from the series of 12-crown-4 early lanthanide chloride complexes that were obtained by slow evaporation ([M(OH 2 ) 5 − (12-crown-4)]Cl 3 ·2H 2 O).Utilization of an electrochemical cell produces complexes in which all three chloride anions are in the metal's primary coordination sphere, the coordination number is reduced, and most of the water or solvent molecules are eliminated.
Mother–Infant Joint Attention and Sharing: Relations to Disorganized Attachment and Maternal Disrupted Communication

The normative development of infant shared attention has been studied extensively, but few studies have examined the impact of disorganized attachment and disturbed maternal caregiving on mother-infant shared attention. The authors examined both maternal initiations of joint attention and infants' responses to those initiations during the reunion episodes of the Strange Situation Procedure at 12 and 18 months of infant age. The mothers' initiations of joint attention and three forms of infant response, including shunning, simple joint attention, and sharing attention, were examined in relation to infant disorganized attachment and maternal disrupted communication. Mothers who were disrupted in communication with their infants at 18 months initiated fewer bids for joint attention at 12 months, and, at 18 months, mothers of infants classified disorganized initiated fewer bids. However, the infant' responses were unrelated to either the infant' or the mother' disturbed attachment. At both ages, disorganized infants and infants of disrupted mothers were as likely to respond to maternal bids as were their lower risk counterparts. Our results suggest that a disposition to share experiences with others is robust in infancy, even among infants with adverse attachment experiences, but this infant disposition may depend on adult initiation of bids to be realized.
The mitogenic properties of rabbit anti-mouse brain serum.

Abstract The mitogenic activity of heterologous rabbit anti-mouse brain sera (RAMB) was investigated. By complement-dependent cytotoxicity and indirect immunofluorescence, RAMB was T-cell specific. Mitogenic activity was assessed by determination of [3H]thymidine incorporation into DNA. RAMB was mitogenic for spleen cells for Thy 1.1- and Thy 1.2-positive mouse strains. Maximal mitogenic responsiveness to RAMB occurred on Day 3 of culture. The incorporation of [3H]uridine into RNA and [3H]leucine into protein and percentage of blast cells in culture were also significantly increased following RAMB stimulation. The mitogenic activity of RAMB was abrogated by adsorption of the sera with BALB/c or AKR thymocytes or brains or with RL♂ 1.3+, a Thy 1.2-bearing T-cell lymphoma of BALB/c origin. In contrast, the mitogenic activity was not removed when RAMB sera were absorbed with RL♂ 1.4−, a variant of RL♂ 1 which appears to specifically lack cell surface Thy 1 determinants. These data suggest that the mitogenic activity of RAMB is Thy 1 directed. RAMB mitogenicity is T-cell dependent. Spleen cells from normal and heterologous nu/+ mice respond to RAMB, while spleen cells from nu/nu mice do not respond. Normal thymocytes and cortisone-resistant thymocytes do not respond mitogenically to RAMB. The response of unseparated spleen cells to RAMB is also macrophage dependent. Nylon-wool column-purified splenic T cells respond to high concentrations of RAMB in the absence of exogenous macrophages but do not respond to lower concentrations of RAMB unless exogenous macrophages are added to the cultures. Nylon-wool-adherent cells, which are B-cell enriched and relatively T-cell depleted, also respond to RAMB, suggesting that in the presence of even small numbers of T cells, B cells can be recruited into the response.
Metal oxide-polymer thermistors

Composites consisting of semi-crystalline or amorphous polymers and a conducting metal oxide filler, V2O3, have been prepared. They exhibit relatively low room temperature resistivities, (PTC) of resistance effects of up to nine orders in magnitude, and an NTC transition near −100' C. A previously proposed model that describes the resistivity behaviour of metal-insulator composites as a function of both temperature and filler concentration has been applied to V2O3-polyethylene and V2O3-rigid epoxy composites. The predictions of this model are then compared with the experimental behaviour of the composites. In addition, SEM micrographs of the composites are shown to illustrate the wetting characteristics of the various polymers on V2O3.
Inorganic nitrogen removal in a combined tertiary treatment-marine aquaculture system—II. Algal bioassays

Abstract Algal bioassays were conducted on samples from various components of the combined tertiary treatment-marine aquaculture process, described in Part I of this study. These assays demonstrated that nitrogen removal is necessary to prevent increasing the algal growth potential of coastal marine waters receiving wastewater discharges. When nitrogen was removed from secondarily treated domestic wastewater, the wastewater in varying dilutions with seawater could not support more algal growth than the seawater alone. By adding nitrogen back to the treated wastewater the algal growth potential was increased to that of the untreated wastewater. This was demonstrated by assaying samples containing both artificially added nitrogen, and nitrogen regenerated by oysters. Assays of the effluent from the seaweed system showed that the removal of regenerated nitrogen reduced the algal growth potential to that of natural seawater.
Effects of thalidomide and pentobarbital on neuronal activity in the preoptic area during sleep and wakefulness in the cat

To test the hypothesis that sleep produced by thalidomide, unlike that of pentobarbital, is associated with increased neuronal activity in the preoptic area (POA), the spontaneous activity of 96 POA neurons was recorded in chronically prepared cats during alert wakefulness (W), deep slow-wave sleep (SWS), and REM sleep in a drug-free preparation and after administration of thalidomide (4mg/kg) and pentobarbital (4 or 8 mg/kg). Thalidomide, unlike pentobarbital, at a dose that significantly increased the amount of SWS, failed to depress neuronal activity in the POA compared to drug-free controls. Mean discharge rates during thalidomide treatment were similar to drug-free rates. In contrast, rates during low-dose pentobarbital treatment were significantly less than those of drug-free and thalidomide-treated animals. Rates during high-dose pentobarbital treatment were significantly less than those in all other groups. Thalidomide, compared with the other groups, in addition to increasing the amount of SWS, significantly increased the total amount of REM sleep as well as REM sleep as a percent of total sleep, but did not produce ataxia or behavioral excitement. These results do not confirm the initial hypothesis, but suggest that hypnotic drugs that do not depress neuronal activity in the POA may be devoid of some of the unwanted side effects often associated with the more commonly prescribed hypnotic medications.
On efficient time-stepping methods for nonlinear partial differential equations

Abstract Efficient procedures for time-stepping Galerkin methods for approximating smooth solutions of quasilinear second-order hyperbolic equations are considered. The techniques presented can be used to analyze approximation procedures for related second-order-in-time quasilinear partial differential equations which have applications including initial-boundary value problems for vibrations (possibly) with inertia, dynamics of rotating fluids, and nonlinear viscoelasticity. The procedure involves the use of a pre-conditioned iterative method for approximately solving the different linear systems of equations arising at each time step in a discrete-time Galerkin method. Optimal order L 2 spatial errors and almost optimal order work estimates are obtained for the second-order hyperbolic case.
Rate-determining step in photocatalytic production of hydrogen

Abstract Photocurrent and dark current measurements were made using n-type and p-type Si electrodes with thin Pd overlayers to determine the rate-determining step in the photocatalytic production of hydrogen. Since exposure of Pd to hydrogen is known to reduce its work function, the possible change in Schottky barrier height was investigated by measuring the onset potential for photocurrent of Si/SiOx/Pd electrodes before and after exposing the electrode surface to hydrogen. At low light intensity (6.4 μW cm−2), the results for n-type and p-type Si/SiOx/Pd electrodes support the predictions of the metal/semiconductor interface model. However, at high light intensity (34 mW cm−2), the results of p-type Si/SiOx/Pd electrodes are found to be in agreement with the metal/solution interface model. The dependence of the photocurrent change on light intensity suggests that the magnitude of the surface recombination rate constant is important in locating the rate-determining step in the photoelectrochemical system.
Examination of gamma-irradiated fruits and vegetables by electron spin resonance spectroscopy

Abstract The ESR spectra of the seeds, pits, shells, and skins of a variety of irradiated fruits and vegetables were measured. All spectra, control and irradiated, contained a single resonance with a g-factor of 2.00. Additional resonances due to Mn2+ were observed for the drupelets of blackberries and red raspberries. An unusual radiation-induced radical was observed for irradiated mango seed; however, the signal decayed completely within a few days. It was concluded that only in a few specialized cases could the ESR resonances observed be suitable for postirradiation monitoring or dosimetry.
IL-15 converts human intestinal intraepithelial lymphocytes to CD94+ producers of IFN-γ and IL-10, the latter promoting Fas ligand-mediated cytotoxicity

Intestinal intraepithelial lymphocytes (IELs), T-cell receptor alphabeta(+) CD8(+) T cells located between epithelial cells, are thought to contribute to Fas ligand (FL)-mediated epithelial cell death in coeliac disease, a condition characterized by excess interleukin-15 (IL-15). This study evaluates the effects of prolonged IL-15 stimulation on IELs. Human IELs were obtained from jejunal mucosa from gastric bypass operations for morbid obesity and cultured for 3 or 10 days with IL-15. As the culture progressed, an increasing number of IELs became CD94(+) and produced massive quantities of interferon-gamma (IFN-gamma) and IL-10. There was a steady rate of transcription with no feedback regulation. Few chronically activated IELs produced IL-2, IL-4, or tumour necrosis factor-alpha (TauNuF-alpha). To determine whether the accumulation of IL-10 affected IEL functions, endogenous IL-10 was neutralized by antibody during culture with IL-15. This manipulation reduced expression of CD94, NKG2D, and FL as well as FL-mediated killing of Jurkat cells by IELs. It did not affect perforin or TNF-alpha expression or the associated cytotoxic activities. This study shows that IL-15 induces the development of CD94(+) IELs containing IFN-gamma and IL-10, and that endogenous IL-10 promotes FL-mediated cytotoxicity.
A Cell-Cycle Nuclear Autoantigen Containing Wd-40 Motifs Expressed Mainly in S and G2-Phase Cells

Recently a novel nuclear protein mainly expressed in S and G2 phase cells was characterized using autoantibodies from a cancer patient (Exp. Cell Res., 212, 255-261, 1994). cDNA clones were isolated by immunoscreening, and sequence analysis revealed that the cDNA clones encoded a 713-amino acid residue polypeptide which is provisionally named SG2NA (S/G2 nuclear antigen). In the carboxyl terminal half of SG2NA, there are 6 copies of WD-40 motifs characteristic of a large family of proteins of which the prototype is beta-transducin/enhancer of split (TLE). In addition, there are nuclear localization sequence and phosphorylation sites related to the TLE proteins. Autoantibodies occurring spontaneously in certain cancer patients have been useful reagents for identifying cellular proteins and this is the first report of a novel WD-40 protein which is the target of an autoimmune response.
Evidence for Hormone-Sensitive Lipase mRNA Expression in Human Monocyte/Macrophages

The role of hormone-sensitive lipase (HSL) in the hydrolysis of adipose tissue triacylglycerol to provide free fatty acids for energy requirements has been well established. However, the role of HSL in other tissues, including macrophages, is not well understood. The demonstration that HSL is capable of hydrolyzing cholesteryl esters at approximately the same rate as triacylglycerol raised the possibility that HSL activity in macrophages may influence the accumulation of cholesteryl esters in foam cells of atherosclerotic lesions. We and others have previously demonstrated that HSL mRNA is expressed in murine peritoneal macrophages and macrophage cell lines; however, it was previously reported that HSL mRNA is absent in human monocyte-derived macrophages, suggesting that a species difference may exist. To clarify this point, we have further examined the issue of HSL mRNA expression in human macrophages. In the current study, we demonstrate that HSL mRNA is detectable in human monocyte-derived macrophages and in the THP-1 human monocyte cell line using reverse transcription coupled to polymerase chain reaction (RT-PCR). Specific amplification of cDNA derived from mRNA was ensured by using primers that span an intron within the human HSL gene, and the identity of PCR products as HSL was confirmed by hybridization to HSL cDNA and by DNA sequencing. Using a semiquantitative PCR assay, we establish that HSL mRNA levels in monocyte/macrophages are approximately 1/40 the levels in human adipose tissue. These results indicate that further studies addressing the role of HSL in macrophage metabolism and its potential role in development of foam cells in human atherosclerotic lesions are warranted.
Statistical long-range transport models

Abstract Statistical long-range transport models are based on the premise that long-term averages of concentration and deposition of pollutants can be estimated with information on the statistics of the governing processes of dispersion, scavenging and chemistry. This paper discusses the formulation of these models, their performance against observations, and their limitations. It is then shown how the simplicity of statistical models can be exploited in the analysis of observations.
WEST NILE VIRUS INFECTION IN FARMED AMERICAN ALLIGATORS (ALLIGATOR MISSISSIPPIENSIS) IN FLORIDA

In September and October 2002, an epizootic of neurologic disease occurred at an alligator farm in Florida (USA). Three affected American alligators (Alligator mississippiensis) were euthanatized and necropsied, and results confirmed infection with West Nile virus (WNV). The most significant microscopic lesions were a moderate heterophilic to lymphoplasmacytic meningoencephalomyelitis, necrotizing hepatitis and splenitis, pancreatic necrosis, myocardial degeneration with necrosis, mild interstitial pneumonia, heterophilic necrotizing stomatitis, and glossitis. Immunohistochemistry identified WNV antigen, with the most intense staining in liver, pancreas, spleen, and brain. Virus isolation and RNA detection by reverse transcription–polymerase chain reaction confirmed WNV infection in plasma and tissue samples. Of the tissues, liver had the highest viral loads (maximum 108.9 plaque-forming units [PFU]/0.5cm3), whereas brain and spinal cord had the lowest viral loads (maximum 106.6 PFU/0.5cm3 each). Virus ti...
Antibiotic dosing issues in lower respiratory tract infection: population-derived area under inhibitory curve is predictive of efficacy

Several lower respiratory tract infection (LRTI) trials have documented a correlation between clinical response and area under the inhibitory curve (24 h AUC/MIC; AUIC). The AUIC values in these studies were based on measured MICs and measured serum concentrations. This study evaluates AUIC estimates made using population pharmacokinetic parameters, and MICs from an automated microbiological susceptibility testing system. A computer database review over 2 years yielded 81 patients at Millard Fillmore Hospital with a culture-documented gram-negative LRTI who had been treated with piperacillin and an aminoglycoside, ceftazidime, ciprofloxacin or imipenem. Their AUIC values were estimated using renal function, drug dosages and MIC values. Outcome groups (clinical and microbiological cures and failures) were related to the AUIC values using Kruskal-Wallis ANOVA, linear regression and classification and regression tree (CART) analysis. A significant breakpoint for clinical cures was an AUIC value at least 72 SIT(-1) x 24 h (inverse serum inhibitory titre integrated over time). All antibiotics performed significantly better above this value than below it. Clinical cure was well described by a Hill-type equation. Within the piperacillin/aminoglycoside regimen, most of the activity came from the piperacillin, which had a higher overall AUIC value than the aminoglycoside. AUIC estimations based upon MIC values derived from the automated susceptibility testing method differed from NCCLS breakpoint data and from tube dilution derived values in this hospital by as much as three tube dilutions. These automated methods probably overestimated the MIC values of extremely susceptible organisms. The lack of precise MIC estimates in automated clinical microbiology methods impairs the use of AUIC to prospectively optimize microbiological outcome. Even ignoring this limitation and using the values as they are reported, the results of this analysis suggest that AUIC targets between 72 and 275 SIT(-1) x 24 h are useful in predicting clinical outcome.
Evaluation of the Predictive Abilities of a Qualitative Exposure Assessment Model

Various qualitative exposure assessment models based on different underlying assumptions requiring distinct inputs and providing diverse outputs are used by occupational hygienists and risk managers to evaluate the magnitude of occupational exposures. Although a wide variety of exposure assessment models are available, most models have not been validated. This study compared the inhalation risk factor of a qualitative exposure assessment model with quantitative exposure data collected at a manufacturing facility for more than 9 years for 12 worker groups involving 24 chemical agents. A Spearman's rho correlation found no significant correlation between the model's risk factor and the maximum measured exposure (rs = 0.119, p = 0.496). A Fisher exact test found that the maximum measured exposure was independent of the model's inhalation risk factor (χ2 = 0.203, p = 0.653). The model accurately classified measured exposures in 18 out of 35 cases (51%), 53% of the measured exposures classified as acceptable w...
Monitoring in pediatric intensive care

Monitoring plays an essential role in the management of critically ill children, although continuous observation along with frequent clinical examination remains the best readily available monitor. Unfortunately, human beings do not have the capability of a prolonged, uninterrupted attention span and nurses often have multiple tasks assigned that limit their ability for continuous observation. Furthermore, some information cannot be obtained accurately by clinical examination alone, e.g. oxygen saturation, ICP, etc. Therefore, it is important to understand the principles and practical points to be able to use these monitors, and first rule out malfunction, disconnection, or improper electrode placement when abnormal reading appear on these monitors before initiating clinical intervention on patient.
The Effects of Antibody Sperm‐Egg Interaction

Previous studies have shown that high titers of antisperm antibodies are correlated with low fertility. Furthermore, immunosuppressive therapy enhances pregnancy in some individuals. Serum tests, however, provide only an indirect measure of a potential pool of antisperm antibodies. When men have antibodies, direct measurement of the percent of sperm that are entirely antibody bound is a more appropriate approach. Antibodies can affect fertilization at many sites. Since sperm are composed of numerous antigens, many antibodies can develop but not all of them will interfere with infertility. Better tests are necessary to define which antibodies may affect fertility. To do that requires the development of better antigens. Use of monoclonal antibodies allows a framework for such further modifications.
Anesthetic effects on [H+]a and muscle metabolites at rest and following exercise

Abstract We determined the effects of ether, intra-arterial Na + pentobarbital (SP) and decapitaion on arterial [H + ] and labile metabolites in plantaris, diaphragm and intercostal muscles of rats at rest and following exhaustive treadmill exercise. 30–60 sec post-analgesia arterial [Lactate] ([LA]a) increased with both anesthetics. SP rats retained CO 2 resulting in mixed acidosis, while ether anesthetized rats hyperventilated and maintained pH. During recovery from exercise ether anesthesia had no effect but SP anesthesia caused CO 2 retention. Decenpitation of resting rats markedly decreased [CP] and elevated [LA] and [G6P] in all three muscles, thereby negating any subsequent exercise effects. The effects of ether differed from those of SP in that with ether anesthesia: (1) [CP]/[Total Creatine] dell and [LA] rose significantly with exercise; (2) resting [LA] was lower and increased with exercise; and (3) metabolite variability was less with ether than with SP. We conclude that: (a) anesthesia obscured the true effects of exercise on acid-base status by increasing [LA]a in the resting state; (b) decapitation is unsuitable for the study of exercise effects on most muscle metabolites; (c) ether anesthesia is most suitable for use in studies aimed at detecting exercise effects on muscle metabolites and for preserving arterial acid-base status closest to the unanesthetized state.
Configurational properties of tobacco mosaic virus ribonucleic acid

The configuration of nearly monodisperse tobacco mosaic virus (TMV) ribonucleic acid (RNA) of molecular weight 2·0 ± 0·1 million was studied at 20 to 25°C in 0·1 M -sodium phosphate buffer, pH 6·8, by light scattering, sedimentation, viscosity, optical rotary dispersion, and optical absorbance measurements. Results show that the partly helical configuration stable under these conditions behaves hydrodynamically as a randomly coiled polymer chain. The RNA chain becomes more compact when solutions are heated briefly to temperatures as high as 80°C and cooled rapidly, or allowed to stand at 25°C for 2 days, no change in molecular weight or distribution being observed under these conditions. The helix-coil transition was observed by optical rotary dispersion measurements at 21 and 71°C, the critical wave length changing from 2500 to 3100 A, and by relative absorbance-temperature profiles as a function of both monovalent and divalent counterion concentrations. Mg2+ was found to be about 25,000 times more effective than Na+ in stabilizing the helical regions of RNA. However, the addition of Na+ to solutions of RNA containing Mg2+ does not increase but decreases the helix stability. If the ratio of Na+ to Mg2+ is high enough (about 1500) the temperature of the helix-coil transition is determined by the Na+ rather than by the Mg2+ concentration. The helix-coil transition was also studied by measuring both the absorbance and the sedimentation coefficient as a function of the concentration of added sodium. The observation that a marked increase in sedimentation coefficient coincides with the increase in hypochromicity led to the suggestion that the configurational transition is reflected by a large change in the overall spatial arrangement of the segments of the RNA chain and not just by local variations along the chain. From the sharpness of the distribution of sedimentation coefficients throughout the transition region, it seems likely that all the RNA molecules from TMV behave identically, as expected from their uniform primary chemical structure.
Classification of amyloid-positivity in controls: comparison of visual read and quantitative approaches.

Abstract An important research application of amyloid imaging with positron emission tomography (PET) is detection of the earliest evidence of fibrillar amyloid-beta (Aβ) deposition. Use of amyloid PET for this purpose, requires a reproducible method for defining a cutoff that separates individuals with no significant Aβ deposition from those in which Aβ deposition has begun. We previously reported the iterative outlier approach (IO) for the analysis of Pittsburgh Compound-B (PiB) PET data. Developments in amyloid imaging since the initial report of IO have led us to re-examine the generalizability of this method. IO was developed using full-dynamic atrophy-corrected PiB PET data obtained from a group of control subjects with a fairly distinct separation between PiB-positive [PiB(+)] and PiB-negative [PiB(−)] subjects. Methods We tested the performance of IO using late-summed tissue ratio data with atrophy correction or with an automated template method without atrophy correction and tested the robustness of the method when applied to a cohort of older subjects in which separation between PiB(+) and PiB(−) subjects was not so distinct. Results The IO method did not perform consistently across analyses and performed particularly poorly when separation was less clear. We found that a sparse k-means (SKM) cluster analysis approach performed significantly better; performing more consistently across methods and subject cohorts. We also compared SKM to a consensus visual read approach and found very good correspondence. Conclusion The visual read and SKM methods, applied together, may optimize the identification of early Aβ deposition. These methods have the potential to provide a standard approach to the detection of PiB-positivity that is generalizable across centers.
Egalitarian Perspectives: Essays in Philosophical Economics

Introduction Part I. Exploitation: 1. Exploitation, alternatives, and socialism 2. Property relations vs. surplus value in Marxian exploitation 3. Should Marxists be interested in exploitation? 4. What is exploitation? Reply to Jeffrey Reiman 5. Second thoughts on property relations and exploitation Part II. Equality of Resources: 6. Equality of talent 7. Egalitarianism, responsibility, and information 8. A pragmatic theory of responsibility for the egalitarian planner Part III. Bargaining Theory and Justice: 9. The mismarriage of bargaining theory and distributive justice 10. A challenge to Neo-Lockeanism 11. Informational complexity in axiomatic models: benefits and costs 12. Distributing health: the allocation of resources by an international agency Part IV. Public Ownership and Socialism: 13. On public ownership 14. The morality and efficiency of market socialism 15. A future for socialism.
Sensitive high-performance liquid chromatographic determination of chlorzoxazone and 6-hydroxychlorzoxazone in plasma

A rapid and sensitive high-performance liquid chromatographic assay was developed for the quantitation of chlorzoxazone and its major metabolite 6-hydroxychlorzoxazone in plasma. These compounds, as well as the internal standard 5-fluorobenzoxazolone, were extracted from plasma (0.5 ml) using C18 solid-phase extraction columns. The extracts were analyzed on a 10-μm Waters C18 μBondapak column with a mobile phase of acetonitrile—tetrahydrofuran—0.1 M ammonium acetate (22.5:5.5:72). The assay utilized ultraviolet detection (283 nm) which provided sensitivity and specificity sufficient to simultaneously quantify ≥ 100 ng/ml chlorzoxazone and 6-hydroxychlorzoxazone in plasma. The mean correlation coefficient of the multi-level standard curves for each compound was 0.996 or greater over a concentration range of 100–3000 ng/ml. The inter-day and intra-day coefficients of variation were <6%. This method has been used by our laboratory to provide the unattended overnight analysis of chlorzoxazone and 6-hydroxychlorzoxazone in plasma samples obtained from human study subjects.
Feasibility of a High-Temperature Polymer-Derived-Ceramic Turbine Fabricated Through Micro-Stereolithography

Efficient micro turbines are expected to play a major role in power generation in the coming years. One of the biggest challenges in significantly increasing the system efficiency from the currently achievable values is the availability of high temperature materials that can be micro-fabricated with a low value of relative tolerance. This paper suggests a possible solution for both the material and the fabrication technique by which this goal can be achieved. Thermodynamic analysis shows that high turbine inlet temperatures, high isentropic efficiencies, and a recuperator with high effectiveness and low pressure losses are imperative to improve system efficiency, particularly in a micro turbine. An excellent relative tolerance with a high temperature ceramics is one way to achieve these improvements. The paper introduces new polymer-derived-ceramics (PDC), which could be used in turbine and recuperator designs. These materials can be used in micro-fabrication techniques to produce absolute tolerances of a few microns, and some of them are thermally stable up to 1800°C in air. The paper presents an enhancement to the typical micro-stereolithography technique, by which PDC can be micro-fabricated to form parts up to a few centimeters in overall linear dimensions and yet to have a relative tolerance that is comparable to or better than that in large-sized conventional parts. It is projected that for a turbine with 10 cm rotor outside diameter and 5 mm blade height, a tip-gap-to-blade-height ratio of better than 0.28% can be achieved by this proposed enhancement. This technique appears to be quite promising for next generation micro turbines, and hence requires further investigation and development.Copyright © 2002 by ASME
Effect of carbon tetrachloride on distribution and disappearance of labeled insulin in rabbit serum.

Summary1. The disappearance rate and distribution of I131 labeled insulin in the serum of white rabbits was studied under various degrees of injury with carbon tetrachloride and after bilateral nephrectomy. Radioactivity was determined in the protein bound phase. 2. Disappearance of labeled material from the serum could be expressed by a first order relationship. Disappearance rate was most dependent on presence of intact kidneys and was relatively independent of CCI4 damage to the liver. 3. The theoretical value for serum concentration of labeled material at time O was increased by severe CCI4 damage to the liver but was relatively independent of the status of kidney function. 4. Lower glucose values in the blood, both fasting and after insulin, were found in the CCl4 injured animals.
A Novel Enzyme That Catalyzes the Esterification of N-Acetylsphingosine METABOLISM OF C2-CERAMIDES

A unique transacylase that catalyzes esterification of a short chain ceramide, N-acetylsphingosine, was found in Madin-Darby canine kidney cell and mouse tissue homogenates. It esterified the hydroxyl group at the carbon-1 position of the ceramide. The enzyme has a pH optimum of 4.2 and a Km of 9.4 microM for N-acetylsphingosine at pH 4.5. The transacylase activity is independent of free fatty acid or acyl-CoA and instead uses the 2-acyl group of phosphatidylethanolamine or phosphatidylcholine. The transacylase activity in the homogenate was present in the 100,000 x g supernatant, and the lipid extracted from the membranous fraction could function as a donor of the acyl group. When liposomes consisting of dioleoylphosphatidylcholine:1-palmitoyl-2-[14C]arachidonoyl-phosphati dylethanolamine:sulfatide (70:0.2:30) were incubated with the supernatant and N-acetylsphingosine, the formation of free arachidonic acid and O-arachidonoyl-N-acetylsphingosine was observed. The ratio of the two products depended on the concentration of ceramide; only the free acid was formed if the truncated ceramide was absent. Both deacylase and transacylase activities were inhibited 50-60% by 20 microM D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol, an inhibitor of several glucosphingolipid synthases. Neither activity was inhibited by nonadecyltetraenyl trifluoromethyl ketone, a potent inhibitor of cytosolic phospholipase A2. N-Acetyldihydrosphingosine and N-octanoylsphingosine were only 55 and 10%, respectively, as effective as N-acetylsphingosine as acyl acceptors. Oleoylsphingosine was only slightly reactive. An esterase that releases the truncated ceramide from its ester linkage appears to be membrane bound. Lecithin was less effective than phosphatidylethanolamine as an acyl donor in the transacylation. Madin-Darby canine kidney cell cultures treated with N-acetyl-[3-3H]sphingosine formed radioactive polar sphingolipids, long chain ceramide, free sphingosine, and O-acyl-N-acetylsphingosine. This suggests that the deacylation and transacylation reactions observed in vitro occur in growing cells as well.