cssi/SciSciGPT-SciSciNet huggingface dataset:
Aging affects the drug metabolism systems of rat liver, kidney, colon and lung in a differential fashion.

Abstract Microsomes prepared from the liver, lungs, colon and kidney cortex of Sprague Dawley rats of ages 2, 4, 10, 24 and 78 weeks were assessed for hydroxylation activity with the substrate benzo[α]pyrene. Liver microsomal activity declined after reaching a peak of activity at 10 weeks. The hydroxylation of benzo[α]pyrene by colon, kidney and lung microsomes, however, either remained the same or decreased only slightly. During the age range examined inducibility of hydroxylation activity by β-naphthoflavone decreased with age in liver but actually increased with age in the extraphepatic tissues. Although phenobarbital did not elicit any increases in liver, kidney or lung, it increased substantially benzo[α]pyrene hydroxylation activity in colon microsomes of 78 week old rats. Total cytochrome P-450 content was induced at all age groups in all tissues by β-naphthoflavone and in all tissues except lung by phenobarbital. Induction of cytochrome P-450 in kidney by phenobarbital was only observed in 24 and 78 week old rats. These data suggest an increased role for extrahepatic activation of benzo[α]pyrene with aging. In contrast to total content of cytochrome P-450, the β-naphthoflavone inducible amount of Form 5 which has a high turnover number for benzo[α]pyrene, declined by 55% in liver between 2 weeks and 78 weeks while it increases dramatically in all extrahepatic tissues (from 80 to 138%).
The impact of fare and gasoline price changes on monthly transit ridership: Empirical evidence from seven U.S. transit authorities

Abstract This paper presents eight empirical models of monthly ridership for seven U.S. Transit Authorities. Within the framework of these models, the impacts upon monthly ridership from changes in the real fare and gasoline prices are examined. Important findings are: (1) the elasticities of monthly transit ridership with respect to the real fare are negative and inelastic, ranging from 0.042 to 0.62; and (2) the elasticities of monthly transit ridership with respect to the real gasoline price are positive and inelastic, ranging from 0.08 to 0.80. Such results have important policy implications for decisions based on the relationships of price, revenue, and ridership; and for assessing the impacts of changing gasoline prices upon urban modal choice.
DIARRHEA-ASSOCIATED ADENOVIRUSES: RAPID PRESUMPTIVE DIAGNOSIS BY ELECTRON MICROSCOPY

There is a need for the rapid recognition of infection by the newly-described enteral or diarrhea-associated adenoviruses (adenoviruses that are of proposed neutralizing serotypes 40 and 41, or that have restriction endonuclease electrophoretic profiles of Wadell groups F or G). These viruses especially infect infants, and they tend to be fastidious in their growth in conventional cell cultures. During a 6 minute viewing per specimen, adenoviruses were visualized by direct electron microscopy (EM) or immune EM in the stools of 52 pediatric inpatients with acute gastroenteritis. Forty (77%) of these viruses proved to be enteral adenoviruses on the basis of neutralization test in 293 cells and/or electrophoretic profile. However, only 5 (36%) of 14 patients with less than 1 adenovirus particle per minute of direct EM viewing of the original diarrhea stools were found to have an enteral adenovirus, as compared to 35 (92%) of 38 patients with 1 or more such particles per minute of viewing (X2 = 18.34, P = < .01). Thus the quantity of adenoviruses found in a diarrhea stool would appear to provide a strong presumptive indication of the presence or absence of an enteral adenovirus. This determination can be made within 15 minutes of specimen collection.
High-temperature seafloor hydrothermal circulation over geologic time and archean banded iron formations

[1] Under the assumption of simple plate tectonics with a range of continental growth scenarios, we construct models of global lithospheric heat loss, hydrothermal heat loss and hydrothermal iron flux to the ocean as functions of geologic time from 4.0 Ga to present. The models show that lithospheric heat loss scales with the square root of the plate creation rate, whereas hydrothermal heat loss scales linearly with that rate. Thus during the Archean lithospheric and hydrothermal heat losses were ≈3 and ≈10 times greater than present, respectively. Straightforward extrapolation of hydrothermal Fe flux from the present to the Archean using these models indicates that hydrothermal Fe may not have been sufficient to supply the large Superior-type Banded Iron Formations deposited between 2.7 and 1.8 Ga.
Training to Improve Calibration and Discrimination: The Effects of Performance and Environmental Feedback.

This study investigated whether calibration and discrimination are distinct or related aspects of probability judgment accuracy by examining the effects of two different training techniques. Participants received either performance feedback or environmental feedback, and we measured their improvement in calibration and discrimination as a function of feedback type. Whereas performance feedback reduced participants' overconfidence and environmental feedback improved discrimination, neither type of feedback led to an improvement on the other component. In fact, environmental feedback led to an increase in overconfidence. We take these results as evidence that calibration and discrimination are dissociable abilities that require separate training techniques for improvement.
Discrete models/continuous models

Abstract Continuous approximations are useful in formulating models that humans can comprehend. Discrete approximations are useful in formulating models that computers can “comprehend”. Applications of discrete and continuous approximations are illustrated with examples.
Scatter and veiling glare estimation based on sampled primary intensity.

Scatter and veiling glare are predominant sources of error in videodensitometric iodine quantification. Standard beam stop techniques such as lead strips or an array of lead discs, placed before the patients, have previously been used to measure scatter and veiling glare in digital radiographic images. However, these techniques significantly increase patient x-ray exposure. In order to overcome this limitation, a scatter measurement technique based on sampled primary intensity has been investigated. This technique uses an array of apertures in a lead sheet to sample the primary x-ray intensity. The scatter–glare intensity in these locations is calculated by subtracting the sampled primary intensity from an open field image which contains both primary and scatter–glare. The calculated scatter–glare values can be interpolated or combined with digital filtration to estimate the scatter–glare intensity on a pixel by pixel basis. The technique was evaluated using a Lucite™ step phantom and an anthropomorphic chest phantom. The average rms percentage errors of scatter and veiling glare estimation using bi-cubic interpolation and digital filtration techniques were 8.02% and 7.53%, respectively. The average rms percentage errors of primary intensity estimation using bi-cubic interpolation and digital filtration techniques were 10.01% and 8.91%, respectively. The x-ray exposure-area product (EAP) from the aperture array was only 4.38% of the EAP from the open field. These results indicate that the scatter–glare intensity can be accurately estimated with minimal x-ray exposure using sampled primary intensity.
Regulation of the transcription factor EB-PGC1α axis by beclin-1 controls mitochondrial quality and cardiomyocyte death under stress

In cardiac ischemia-reperfusion injury, reactive oxygen species (ROS) generation and upregulation of the hypoxia-inducible protein BNIP3 result in mitochondrial permeabilization, but impairment in autophagic removal of damaged mitochondria provokes programmed cardiomyocyte death. BNIP3 expression and ROS generation result in upregulation of beclin-1, a protein associated with transcriptional suppression of autophagy-lysosome proteins and reduced activation of transcription factor EB (TFEB), a master regulator of the autophagy-lysosome machinery. Partial beclin-1 knockdown transcriptionally stimulates lysosome biogenesis and autophagy via mTOR inhibition and activation of TFEB, enhancing removal of depolarized mitochondria. TFEB activation concomitantly stimulates mitochondrial biogenesis via PGC1α induction to restore normally polarized mitochondria and attenuate BNIP3- and hypoxia-reoxygenation-induced cell death. Conversely, overexpression of beclin-1 activates mTOR to inhibit TFEB, resulting in declines in lysosome numbers and suppression of PGC1α transcription. Importantly, knockdown of endogenous TFEB or PGC1α results in a complete or partial loss, respectively, of the cytoprotective effects of partial beclin-1 knockdown, indicating a critical role for both mitochondrial autophagy and biogenesis in ensuring cellular viability. These studies uncover a transcriptional feedback loop for beclin-1-mediated regulation of TFEB activation and implicate a central role for TFEB in coordinating mitochondrial autophagy with biogenesis to restore normally polarized mitochondria and prevent ischemia-reperfusion-induced cardiomyocyte death.
Relation between hen egg white lysozyme and bacteriophage T4 lysozyme: evolutionary implications.

Abstract Hen egg white lysozyme and T4 bacteriophage lysozyme have the same catalytic function, but have non-homologous amino acid sequences. Notwithstanding the differences in their primary structures, the two lysozymes have similarities in their overall backbone conformations, in their modes of binding substrates and probably in their mechanisms of action. By different criteria, the similarity between the folding of the two enzymes can be shown to be statistically significant. Also the transformation which optimizes the agreement between the backbones of the two molecules is shown to accurately align their active site clefts, so that saccharide units bound in the A, B, C and D subsites of hen egg white lysozyme coincide within 1 to 2 A with analogous saccharides bound to phage lysozyme. Furthermore, a number of the specific interactions between enzyme and substrate which were observed for hen egg white lysozyme, and thought to be important for catalysis, are found to occur in a structurally analogous way in the phage enzyme. Fifty-four atoms from the respective active sites which appear to be equivalent, including saccharides bound in the B and C sites, superimpose with a root-mean-square discrepancy of 1.35 A. These structural and functional similarities suggest that the two lysozymes have arisen by divergent evolution from a common precursor. This is the first case in which two proteins of completely different amino acid sequence have been shown, with high probability, to have evolved by divergent rather than convergent evolution.
Transpiration Cooled Porous Type Vi Silica Rocket Windows

A novel use of sol-gel derived porous Type VI silica for high performance rocket guidance system windows is evaluated. The samples produced for this study were optically transparent hydrofluoric and/or nitric acid catalyzed tetramethylorthosilicate (TMOS) xerogel monoliths with average pore radii of 1.2, 5.0, and 8.Onm. Maximum He transpiration velocities of up to 3 cm/sec, 3 times the velocity needed for transpiration cooling, are measured for a 5.0 nm sample at 3.2 MPa. Transpiration velocities of 0.6 cm/sec result in cooling effects as large as 44°C from 160°C.
A high order WENO finite difference scheme for incompressible fluids and magnetohydrodynamics

We present a high order accurate weighted essentially non-oscillatory (WENO) finite difference scheme for solving the equations of incompressible fluid dynamics and magnetohydrodynamics (MHD). This scheme is a direct extension of a WENO scheme that has been successfully applied to compressible fluids, with or without magnetic fields. A fractional time-step method is used to enforce the incompressibility condition. Two basic elements of the WENO scheme, upwinding and wave decomposition, are shown to be important in solving the incompressible systems. Numerical results demonstrate that the scheme performs well for one-dimensional Riemann problems, a two-dimensional double-shear flow problem, and the two-dimensional Orszag–Tang MHD vortex system. They establish that the WENO code is numerical stable even when there are no explicit dissipation terms. It can handle discontinuous data and attain converged results with a high order of accuracy.
Refining multimeric protein complexes using conservation, electrostatics and probabilistic selection

We introduce a multimeric docking refinement method that uses a scoring function based on a tight coupling between evolutionary conservation, geometry and pairwise interactions. Detection of protein complexes and their structures is crucial for understanding the role of protein complexes in the basic biology of organisms. Computational methods can provide researchers with a good starting point for the analysis of protein complexes. However, computational docking methods are often not accurate and their results need to be further refined to improve interface packing. Additionally, most docking methods focus on dimers due to the exponential growth in computational complexity caused by the addition of monomeric units. Multimeric docking and refinement methods should employ efficient selection criteria to reduce the search space. The incorporation of evolutionary conservation allows us to bias our results towards possible functional interface. We combine our search with a probabilistic selection scheme that allows us to escape local energy minima. Our results suggest that our refinement scheme can efficiently handle complexes with more than 2 monomers and help biasing the results towards complexes with native interactions, filtering out false positive results. We produce structures with better IRMSDs with respect to the known complexes and lower energies than those initial docked structures.
Impact of preanalytical variables on granulocytic surface antigen expression: a review.

Background: There is a gradual but steady increase in the use of granulocytic surface marker studies to diagnose several inherited and acquired blood and bone marrow disorders. Diagnosis and follow-up of patients with inflammation and infection are other areas of quantitative flow cytometric application. Despite the increased use of flow cytometry to study granulocytes, there seems to be no well-established standards regarding specimen handling for these studies. Methods: This review summarizes the effect of preanalytical variables on granulocytic surface markers. Results and Conclusions: Storing specimens in sodium heparin at room temperature for up to 72 h seems satisfactory. Other anticoagulants, although acceptable, may have a shorter storage time. Storage time could be prolonged further with the use of some preservation media. Lysed whole blood is the preferred technique. Techniques should avoid major temperature change and excessive manipulation and should maintain storage and methodologic temperature with minimal fluctuation. Fixation before staining with the antibody may result in decreased expression of some surface antigens. q 2005 Wiley-Liss, Inc.
Vanadate enhances but does not normalize glucose transport and insulin receptor phosphorylation in skeletal muscle from obese women with gestational diabetes mellitus

Abstract Objective: We compared the insulin-mimetic effects of vanadate, a protein-tyrosine phosphatase inhibitor, with the effects of insulin on skeletal muscle glucose transport and insulin receptor and insulin receptor substrate 1 phosphorylation to test the hypothesis that protein-tyrosine phosphatases participate in pregnancy-induced insulin resistance. Study Design: Skeletal muscle fiber strips were obtained from the rectus abdominis during cesarean delivery in 7 patients with gestational diabetes mellitus, 11 pregnant women with normal glucose tolerance (pregnant control group), and 11 nonpregnant women undergoing elective surgery (nonpregnant control group). Muscle tissues were incubated in vitro for 15 to 60 minutes with or without maximal insulin (100 nmol/L) or sodium vanadate (6 μmol/L). Insulin receptor and insulin receptor substrate 1 tyrosine phosphorylation were measured, as was 2-deoxyglucose transport. The levels of protein-tyrosine phosphatase 1B were measured by Western blot analysis. Results: Vanadate stimulated maximal 2-deoxyglucose transport more than did insulin alone in all samples ( P P P Conclusion: Vanadate did not restore normal glucose transport activity during pregnancy complicated by gestational diabetes mellitus, which indicates that decreased glucose uptake is probably not caused by impaired tyrosine phosphorylation events alone. Increased serine kinase activity and impaired glucose transporter 4 translocation probably contribute to insulin signaling abnormalities associated with pregnancy, especially in patients with gestational diabetes mellitus. (Am J Obstet Gynecol 2000;183:1263-70.)
Surface tolerance of a radar calibration sphere

The effect of small-amplitude surface irregularities on the backscattering properties of a metal sphere is examined using a full-wave boundary perturbation method. When the irregularities are resolved into their various spherical harmonics, it is shown that their total effect can be expressed as a weighted sum of their individual spectral amplitudes. The behavior of the weight coefficients as a function of both spectral order and frequency is described using graphs and various approximate formulas. This gives the complete description necessary for computing the effect of an arbitrary (small) surface variation for all frequencies from the Rayleigh region through the resonance region to the short wavelength region. The magnitude of the cross-polarized reflected power is included among the effects that can be computed.
Solid state voltammetry of an anthraquinone molten salt

The solid-state voltammetries of the two reduction steps of a novel redox polyether hybridan anthraquinone molten salt (triethyl(MePEG350)ammonium anthraquinone sulfonate, (Et3NMePEG350+)(AQSO3-))and its disulfonated analogue, are reported. Multiple effects on charge transport rates are encountered. Currents for the first reduction step are enhanced by electron self-exchange charge transport, whereas currents for the second reduction wave are greater than 10-fold smaller. The relative charge transport rates of the two reductions are examined as a function of temperature and of incrementally replacing the AQSO3- anion in the melt with the electroinactive BF4- anion. An analysis that includes ionic conductivity measurements shows that the apparent charge transport rate of the second anthraquinone reduction is attenuated primarily as a result of ionic migration of the products of comproportionation reactions occurring in the diffusion layer.
Superconvergence of the iterated collocation methods for Hammerstein equations

In this paper, we analyse the iterated collocation method for Hammerstein equations with smooth and weakly singular kernels. The paper expands the study which began in [16] concerning the superconvergence of the iterated Galerkin method for Hammerstein equations. We obtain in this paper a similar superconvergence result for the iterated collocation method for Hammerstein equations. We also discuss the discrete collocation method for weakly singular Hammerstein equations. Some discrete collocation methods for Hammerstein equations with smooth kernels were given previously in [3, 18].
The tumour suppressor LKB1 regulates myelination through mitochondrial metabolism

A prerequisite to myelination of peripheral axons by Schwann cells (SCs) is SC differentiation, and recent evidence indicates that reprogramming from a glycolytic to oxidative metabolism occurs during cellular differentiation. Whether this reprogramming is essential for SC differentiation, and the genes that regulate this critical metabolic transition are unknown. Here we show that the tumour suppressor Lkb1 is essential for this metabolic transition and myelination of peripheral axons. Hypomyelination in the Lkb1-mutant nerves and muscle atrophy lead to hindlimb dysfunction and peripheral neuropathy. Lkb1-null SCs failed to optimally activate mitochondrial oxidative metabolism during differentiation. This deficit was caused by Lkb1-regulated diminished production of the mitochondrial Krebs cycle substrate citrate, a precursor to cellular lipids. Consequently, myelin lipids were reduced in Lkb1-mutant mice. Restoring citrate partially rescued Lkb1-mutant SC defects. Thus, Lkb1-mediated metabolic shift during SC differentiation increases mitochondrial metabolism and lipogenesis, necessary for normal myelination.
Help-seeking among male victims of partner abuse: Men's hard times.

Sixty-eight agency representatives in the United States completed a survey to identify issues of male victims in partner abuse: half referenced responses from male clients and the other half responses from male victims who were their family members, friends, colleagues, or themselves. Almost 25% revealed that male victims did not utilize social services. For those men who used services, individual counseling and legal advice were most popular; group counseling and sharing through the Internet were least used. Qualitative data found five themes that triggered men's hard times: service target perception, shame and embarrassment, denial, stigmatization, and fear. The study resulted in three recommendations: (a) increase public awareness and education; (b) provide gender-inclusive practice and services, and (c) strengthen training for service providers working with domestic violence male victims.
Recent advances in peptide chiral selectors for electrophoresis and liquid chromatography

The application of peptides in chiral separations using techniques such as capillary electrophoresis (CE), electrokinetic capillary chromatography (EKC) and liquid chromatography is the focus of this review. Methods for finding peptide selectors using combinatorial library approaches are discussed, as well as recent advances in the use of peptides as general chiral selectors for electrophoresis and liquid chromatography. One example shows the effectiveness of polymeric dipeptide surfactants as general chiral selectors for electrophoresis. Another example shows the versatility of oligoproline chiral stationary phases, exhibiting resolution for a number of racemic analytes comparable to other well-established chiral stationary phases.
Expression of heterologous proteins flanked by NS3-4A cleavage sites within the hepatitis C virus polyprotein

Hepatitis C virus (HCV) contributes substantially to human morbidity and mortality world-wide. The development of HCV genomes expressing heterologous proteins has enhanced the ability to study viral infection, but existing systems have drawbacks. Recombinant viruses often require adaptive mutations to compensate for reduced viral titers, or rely on an artificial genomic organization that uncouples viral protein expression from recombinant gene expression. Here, we sought to exploit the viral polyprotein processing machinery to express heterologous proteins within the context of the HCV polyprotein. We show that HCV genotypes 2a and 1b permit insertion of reporter proteins between NS5A and NS5B with minimal impact on viral fitness. Using this strategy we constructed reporter genomes exhibiting a wide dynamic range, simplifying analysis of HCV infection in primary hepatocytes. Expression of heterologous proteins within the HCV genome offers new opportunities to analyze HCV infection in experimental systems without perturbing functions of individual viral proteins.
Endodermal Sinus Tumor of the Mediastinum: Report of Apparent Cure in Two Patients with Extensive Disease

Primary endodermal sinus tumor (EST) of the mediastinum has been regarded as a rare and rapidly fatal germ cell neoplasm. We describe two cases of extensive EST treated with a new high-dose sequential combination chemotherapy regimen (CISCA-VB) followed by radical surgical excision. They are alive at 11 and 20 months, respectively, postoperatively. These cases stand in marked contrast to previously reported series. A new approach to the management of this tumor is proposed.
Novel Approach Against Central Venous Catheter Associated Infection With Acinetobacter Baumannii Biofilm

Central venous catheter (CVC)-associated infections have substantial impacts on morbidity, mortality, and overall cost of health care. Acinetobacter baumannii causes severe infections, survives on abiotic surfaces, colonizes and develops resistant biofilm on different medical devices including CVC. The cranberry contains proanthocyanidines which possess antiadherent activity against colonic bacteria. This study aimed to assess the use of moxifloxacin/cranberry extract combination against A. baumannii biofilm established on CVC. A. baumannii bioflim was developed on silicone CVC and visualized by electron microscopy. The biofilm was treated according to the method described by Aslam et al. Briefly, segments (1 cm) of silicone CVC (Cook, Inc., Bloomington, IN) were incubated in bacterial suspensions (106 CFU/ml) in Mueller Hinton broth to allow biofilm formation. After incubation at 37°C for 24 h, segments were aseptically removed. Four sets of catheter segments (3 segments/each) were suspended for 6 h at 37°C in one of the following solutions: moxifloxacin (0.16 ug/mL), cranberry aqueous extract (10 mg/mL), Mox-Cran combination, or normal saline (NS) as a control. Catheter segments were rinsed 3 times with NS to remove planktonic bacteria. These segments were individually sonicated for 5 min and vortexed for 30s in 1 ml NS. Aliquots (100 uL) of the sonicated fluids and their dilutions were inoculated onto Mueller Hinton agar plates. Each set of experiments was repeated three times. Bacterial colonies (CFU/cm) were counted after incubation for 24 h. The average colony count of each set of experiment was calculated. The average values of the treated sets were divided by the average value of the control percent for calculation of the percentage biofilm reduction in each treatment as compared to the untreated control (NS). Using ANOVA, the significance level for all analyses was <0.05. The effect of moxifloxacin alone was similar to the untreated control. Cranberry extract could reduce the biofilm by almost 90%. Moreover, MoxDran combination could synergistically and completely (100%) eradicate. A. Baumannii biofilm from CVC. There is a dire need for developing novel strategies against microbial biofilms on medical devices, such as the use of combination between safe anti-adherent extracts with antimicrobial agent as a catheter lock solution, to retrieve the infected vascular catheters. The results of this study revealed a promising antibiofilm activity of moxifloxacin/cranberry extract combination for eradication of mature A. baumannii biofilm from CVC (therapeutic approach). Since biofilm prevention is much easier than its eradication, we hypothesize that impregnation or coating of medical devices, including CVC, with such novel and safe combination might be an outstanding tool against biofilm development (prophylactic approach).
Matching, undermatching, and overmatching in studies of choice.

Almost all of 103 sets of data from 23 different studies of choice conformed closely to the equation: log (B(1)/B(2)) = a log (r(1)/r(2)) + log b, where B(1) and B(2) are either numbers of responses or times spent at Alternatives 1 and 2, r(1) and r(2) are the rates of reinforcement obtained from Alternatives 1 and 2, and a and b are empirical constants. Although the matching relation requires the slope a to equal 1.0, the best-fitting values of a frequently deviated from this. For B(1) and B(2) measured as numbers of responses, a tended to fall short of 1.0 (undermatching). For B(1) and B(2) measured as times, a fell to both sides of 1.0, with the largest mode at about 1.0. Those experiments that produced values of a for both responses and time revealed only a rough correspondence between the two values; a was often noticeably larger for time. Statistical techniques for assessing significance of a deviation of a from 1.0 suggested that values of a between .90 and 1.11 can be considered good approximations to matching. Of the two experimenters who contributed the most data, one generally found undermatching, while the other generally found matching. The difference in results probably arises from differences in procedure. The procedural variations that lead to undermatching appear to be those that produce (a) asymmetrical pausing that favors the poorer alternative; (b) systematic temporal variation in preference that favors the poorer alternative; and (c) patterns of responding that involve changing over between alternatives or brief bouts at the alternatives.
Evaluation of a Navier-Stokes prediction of a jet in a crossflow

The interaction between a subsonic jet exhausting perpendicularly through a flat plate into a crossflow is investigated numerically using an implicit, two-factor, partially flux split solver for the thin-layer Navier-Stokes equations. The numerical model is limited to steady and laminar flow for both the jet and crossflow. The accuracy of the method is assessed by comparing computed and experimental results for flows with jet-tocrossflow velocity ratios of 4, 6, and 8. Qualitatively , it is found that all of the global flow physics, including the jet trajectory, the contrarotating vortex pair, entrapment, and the wake region near the flat plate, are captured numerically. The computed velocity field is analyzed to determine the properties of the contrarotating vortex pair. Reasonable quantitative agreement between the computation and the experiment is found for the vortex properties as well as for the jet centerline and the plate pressure distribution. Computational flow visualization techniques are used to provide insight into the physics of the three-dimensional flowfleld.
Chloramphenicol Clearance in Infants

Chloramphenicol clearance was evaluated over one dosing interval in 10 infants after at least 24 hours of therapy to evaluate dosage guidelines using a specific chemical assay. Serum samples were obtained prior to and at 1, 2, 4, and 6 hours after the start of a 20-minute infusion of 24 mg/kg chloramphenicol as the sodium succinate. The chemical assay used is technically simple and is specific for unesterified chloramphenicol. Peak serum concentrations ranged from 20.9 to 94.0 microgram/ml and occurred from 1 to 4 hours after infusion. Clearances ranged from 0.058 to 0.236 l./kg . hr and paralleled previously reported results using different assay methodology. The 4-hour serum chloramphenicol concentrations were significantly lower (P less than 0.05) in infants on phenobarbital. The currently recommended dose of chloramphenicol for severe infections, 100 mg/kg per day, is excessive in some infants. Widely divergent clearance rates prohibit uniform dosage guidelines so that serum level monitoring with an assay specific for chloramphenicol is essential.
The performance of serial, matched-filter acquisition in direct-sequence packet radio communications

The performance of a noncoherent, serial acquisition technique is evaluated for direct-sequence spread-spectrum packet communications. The output of a filter matched to the packet's preamble is sampled at twice the chip rate during acquisition, and each sample is compared with a fixed acquisition threshold. The effect of sample-timing error on the acquisition performance is examined.
Isolation of Two Polyketide Synthase Gene Fragments from the Uncultured Microbial Symbiont of the Marine Bryozoan Bugula neritina

"Candidatus Endobugula sertula," the uncultured microbial symbiont of the bryozoan Bugula neritina, produces ecologically and biomedically important polyketide metabolites called bryostatins. We isolated two gene fragments from B. neritina larvae that have high levels of similarity to polyketide synthase genes. These gene fragments are clearly associated with the symbiont and not with the host.
Technologies for highly parallel optoelectronic integrated circuits

Market consideration motivate optoelectronic integrated circuits for highly parallel intrasystem optical buses. Surface normal device technology is well suited for these applications. System examples highlight device technology issues.
Laser Scanning as a Useful Tool in Implant Retrieval Analysis: A Demonstration Using Rotating Platform and Fixed Bearing Tibial Inserts

Objective methods for analyzing arthroplasty retrieval implants are needed. To address this, we used a readily available laser scanner to analyze damage deviations between cohorts of rotating platform and fixed bearing inserts previously analyzed using traditional, subjective retrieval analysis methods. We asked the following research questions: 1) Do articular surface deviations measured by the scanner correlate with the subjective damage scores? 2) Do articular surface deviations differ between inserts due to design differences? Correlations between deviations and damage scores were present in RP but not FB inserts. Seven different deviation patterns were present between the RP and FB inserts and were a function of design. In conclusion laser scanning was found to be a useful objective tool for analyzing arthroplasty retrievals.
Changes in graduate medical education: A view from radiation oncology

The accreditation process of graduate medical education is changing. This change presents new challenges to teachers of radiation oncology. With the help of the ACR and other institutions, radiation oncology is well positioned to meet this challenge.
Cell adhesion receptors in C. elegans

C. elegans has numerous putative cell adhesion receptors, many of which have vertebrate homologues. The simple body plan of C. elegans , its optical transparency and genetic tractability make it well suited for the study of adhesion receptors and their associated complexes (reviewed by Cox and
Modeling Reacting Gas Flow in the Char Layer of an Ablator

Nonequilibrium modeling of pyrolysis gas products flow through char layer of ablative heat shield
Follicular placenta of the viviparous fish, Heterandria formosa: II. Ultrastructure and development of the follicular epithelium.

Embryos of the viviparous poeciliid fish, Heterandria formosa, develop to term in the ovarian follicle where they undergo a 3,900% increase in embryonic dry weight. Maternal-embryonic nutrient transfer occurs across a follicular placenta that is formed by close apposition of the embryonic surface (i.e., the entire body surface during early gestation and the pericardial amnionserosa during mid-late gestation) to the follicular epithelium. To complement our recent study of the embryonic component of the follicular placenta, we now describe the development and fine structure of the maternal component of the follicular placenta. Transmission electron microscopy reveals that the ultrastructure of the egg envelope and the follicular epithelium that invests vitellogenic oocytes is typical of that described for teleosts. The egg envelope is a dense matrix, penetrated by microvilli of the oocyte. The follicular epithelium consists of a single layer of cuboidal cells that lack apical microvilli, basal surface specializations, and junctional complexes. Follicle cells investing the youngest embryonic stage examined (Tavolga's and Rugh's stage 5-7 for Xiphophorus maculatus) also lack apical microvilli and basal specializations, but possess junctional complexes. In contrast, follicle cells that invest embryos at stage 10 and later display ultrastructural features characteristic of transporting epithelial cells. Apical microvilli and surface invaginations are present. The basal surface is extensively folded. Apical and basal coated pits are present. The cytoplasm contains a rough endoplasmic reticulum, Golgi complexes, and dense staining vesicles that appear to be lysosomes. The presence of numerous apically located electron-lucent vesicles that appear to be derived from the apical surface further suggests that these follicle cells may absorb and process follicular fluid. The egg envelope, which remains intact throughout gestation and lacks perforations, becomes progressively thinner and less dense as gestation proceeds. We postulate that these ultrastructural features, which are not present in the follicles of the lecithotrophic poeciliid, Poecilia reticulata, are specializations for maternal-embryonic nutrient transfer and that the egg envelope, follicular epithelium, and underlying capillary network form the maternal component of the follicular placenta. © 1994 Wiley-Liss, Inc.
The Basics of Brain Development

Over the past several decades, significant advances have been made in our understanding of the basic stages and mechanisms of mammalian brain development. Studies elucidating the neurobiology of brain development span the levels of neural organization from the macroanatomic, to the cellular, to the molecular. Together this large body of work provides a picture of brain development as the product of a complex series of dynamic and adaptive processes operating within a highly constrained, genetically organized but constantly changing context. The view of brain development that has emerged from the developmental neurobiology literature presents both challenges and opportunities to psychologists seeking to understand the fundamental processes that underlie social and cognitive development, and the neural systems that mediate them. This chapter is intended to provide an overview of some very basic principles of brain development, drawn from contemporary developmental neurobiology, that may be of use to investigators from a wide range of disciplines.
Health outcomes of interest for evaluation in the Post-Licensure Rapid Immunization Safety Monitoring Program.

Abstract Active vaccine safety surveillance systems commonly use computerized diagnostic codes to identify potential health outcomes of interest. Evidence concerning the accuracy of these codes is variable, and few systematic reviews are available. This project's aim was to select a list of health outcomes of interest most suitable for evaluation in the Food and Drug Administration's Post-Licensure Rapid Immunization Safety Monitoring (PRISM) program. We conducted an expert elicitation process to develop the list. A comprehensive list of potential health outcomes of interest was formed based on input from a wide variety of vaccine safety experts. We then selected five panelists with senior leadership roles in vaccine safety from both within and outside the FDA. We elicited the experts’ recommendations via a structured, iterative process that included an Internet-assisted telephone conference call and formal voting procedures. The expert panelists identified several criteria as important in their choices, including clinical severity, public health importance, rare or uncommon incidence, relevance to two or more vaccines, and historical association with vaccines. The list of 24 outcomes chosen by the experts and refined by the FDA included ten neurologic outcomes, two circulatory system outcomes, and two musculoskeletal outcomes. The PRISM program plans to conduct a set of evidence reviews on the positive predictive value and other characteristics of existing computerized codes and algorithms to identify these health outcomes of interest.
Objectivity of scoring for the McCarthy drawing tests

Two doctoral level school psychologists independently scored 50 McCarthy drawing booklets. Children producing the drawings ranged from 4–6 to 6–10, with a mean age of 5–11. Interscorer reliability for Draw-A-Design was.93 and for Draw-A-Child was.96. No significant difference occurred in the mean score for either test across scorers.
Calcium Sensitizers and Molecular Mechanisms of Altered Response of Cardiac Myofilaments to Calcium

In this chapter I consider a current perception of the molecular interactions by which Ca-binding to the myofilaments regulates the activity of heart cells, and the response to Ca2+ is modulated. Control of the actin-myosin reaction is not only through Ca2+-binding to troponin C (TnC), but also through steric, cooperative and allosteric processes involving all of the main myofilament proteins—actin, myosin, tropomyosin (Tm), TnC, troponin T (TnT), and troponin I (TnI). The process is modulated by covalent and noncovalent mechanisms. Apart from the importance of these mechansisms in the basic physiological control of heart function, an understanding of control of myofilament activation has taken on new importance for the following reasons: First, it is now clear that altered response of the myofilaments to Ca2+ is a cause of heart failure associated with familial hypertrophic cardiac myopathies as well as in diverse pathologies such as acidosis, ischemia, and stunning. Second, the response of cardiac myofilaments to Ca2+ can be manipulated pharmacologically. Pharmacological agents from a variety of chemical classes increase responsiveness of the myofilaments to Ca2+ by promoting Ca2+ binding to TnC, by altering the transduction of the Ca2+binding signal, and by promoting the actin-myosin reaction.
Diacetylenic phosphatides: a new class of biomaterials

Studies on polymerizable phospholipids, are reported with an emphasis on diacetylenic lipids. By incorporating a diacetylenic moiety two specific goals are achieved; (1) modification of membrane morphologies, and (2) stabilization of the resultant microstructures. To explore the properties of diacetylenic phosphatides, the authors have synthesized and characterized a number of phospholipids. This report deals with the properties of aqueous dispersion of these diacetylenic lipids. >
Madison's Managers: Public Administration and the Constitution and The Politics of Crisis Management: Public Leadership Under Pressure

Madison's Managers: Public Administration and the Constitution. By Anthony M. Bertelli and Laurence E. Lynn, Jr. Baltimore: Johns Hopkins University Press, 2006. 240p. $60.00 cloth, $25.00 paper.The Politics of Crisis Management: Public Leadership Under Pressure. By Arjen Boin, Paul 't Hart, Eric Stern, and Bengt Sundelius. New York: Cambridge University Press, 2005. 182p. $70.00 cloth, $27.99 paper.No undergraduate public administration course would be complete without at least a perfunctory attempt to summarize the never-ending debate about what public administration is. From Woodrow Wilson to “scientific management” to the Brownlow Committee to the Willowbrook Conference and beyond, the position papers and studies pile up; yet the debate (which often seems more like a monologue) continues. Students find this debate unsatisfying, and it is easy to see why. For a craft that prides itself above all on its relevance to practical affairs (as Woodrow Wilson put it, administration is “government in action”), the arguments that students are most often exposed to have the arid scholasticism of medieval disputes about angels dancing on pins. If public administration is so practical, students must be thinking, why cannot its theorists just cut to the chase and tell us how to do it? Or even what it is?
Hypothermia and other treatment options for neonatal encephalopathy: an executive summary of the Eunice Kennedy Shriver NICHD workshop.

HIE is not a single disease from a single cause, and is characterized by great diversity in the timing and magnitude of brain injury. It is therefore unreasonable to expect any single intervention to provide uniformly favorable outcome. The known heterogeneity in neuropathological changes after perinatal HIE combined with potential regional heterogeneity of treatment effects will lead to marked differential effects on outcomes among survivors of HIE (e.g. physical disability versus cognitive deficits). This underscores the need for longer term follow up of all infants with HIE undergoing any treatment. In spite of rapidly accumulating clinical and laboratory data related to hypothermia as a neuroprotective strategy for HIE, the speakers and discussants at the workshop underscored numerous gaps in knowledge in this field summarized in the Table, which compares the gaps identified at the 2005 NICHD workshop8 with current gaps. The participants noted that with only six completed studies1-6 providing information on follow-up for up to 18 months of age, the longer-term neurodevelopmental impact of hypothermia for HIE are pending.23,24 This, they concluded, should lead to an overall measure of caution in applying the new therapy of hypothermia indiscriminately for all cases of HIE. Table 1 Comparison of Categories of Gaps in Knowledge and Change from 2005 to 2010 Based on the available data and large knowledge gaps, the expert panel suggested that although hypothermia is unequivocally a promising therapy for HIE, a substantial proportion of infants still suffer from death or disability despite treatment. Further analysis of existing trial data, development of adjuvant therapies to hypothermia, development of biomarkers and further refinements of hypothermia therapy for use in infants suffering from HIE and clinical trials of therapeutic hypothermia in mid resource settings with different risk factors but adequate facilities and infrastructure are all urgently needed and were identified as areas of high priority for study.
Retroviral delivery of dominant-negative vascular endothelial growth factor receptor type 2 to murine wounds inhibits wound angiogenesis.

Vascular endothelial growth factor (VEGF) is a potent paracrine signal for initiating angiogenesis. Although VEGF can bind to several cell surface receptors, VEGF receptor type 2 (VEGFR2, a.k.a. KDR or flk-1) is the primary receptor responsible for VEGF-induced endothelial cell proliferation. To determine whether the VEGF-VEGFR2 signaling axis has an important role in wound healing angiogenesis, we used a retrovirus to deliver a signaling-defective truncated VEGFR2 (tm VEGFR2) to block VEGF-VEGFR2-induced endothelial cell proliferation in murine wounds. We show that the retroviral construct effectively blocked phosphorylation of VEGFR2 in vitro and we were able to express the truncated receptor in murine wounds. We achieved significant reduction of angiogenesis and granulation tissue formation in murine wounds, but this did not lead to delayed wound closure. In contrast, there was a corresponding increase in wound contraction, showing that functional VEGFR2 intracellular signaling is not critical for normal closure of excisional dermal wounds. Our results show a novel relationship between wound bed vascularity and wound contraction.
Channel-Adaptive Optimal OFDMA Scheduling

Joint subcarrier, power and rate allocation in orthogonal frequency division multiple access (OFDMA) scheduling is investigated for both downlink and uplink wireless transmissions. Using a time-sharing argument, a convex formulation is obtained avoiding the NP-hardness of the usual 0-1 integer program solution. It is rigourously established that the optimal allocation can be obtained almost surely through a greedy water-filling approach with linear complexity in the number of users and subcarriers. Stochastic approximation is further employed to develop on-line algorithms which are capable of dynamically learning the underlying channel distribution and asymptotically converges to the off-line optimal solution from arbitrary initial values.
Modeling the user acceptance of e-mail

The technology acceptance model (TAM) predicts whether users will ultimately use software applications based upon causal relationships among belief and attitudinal constructs that influence usage behavior. Electronic mail, or email, is a collaborative technology available to virtually all members of an organization, and typically, there are alternative email applications available for use. This study applies TAM to assess the user acceptance and voluntary usage of a particular email application, cc:mail, in two different organizations. The results largely validate TAM, although the findings suggest that certain external variables, namely length of time since first use, and level of education, directly affect email usage behavior apart from their influence as mediated through the perceived usefulness (PU) and perceived ease of use (PEOU) constructs.