cssi/SciSciGPT-SciSciNet huggingface dataset:
Mutations in a putative zinc-binding domain inactivate the mitochondrial intermediate peptidase.

Abstract The mitochondrial intermediate peptidase (MIP) cleaves characteristic octapeptides, (F/L/I)XX(T/S/G)XXXX(↓), from the N-terminus of many imported mitochondrial proteins. This leader peptidase is activated by divalent cations and inactivated by thiol-blocking agents, properties which are typical of metallo- and cysteine-proteases, respectively. To elucidate the mechanism of action of MIP, we analyzed by site-directed mutagenesis the functional role of a putative zinc-binding domain (F- H-E-X-G-H -(X)2-H-(X)12-G-(X)5-D-(X)2- E -X-P-S-(X)3-E) and two cysteine residues (C131 and C581), which are highly conserved in evolutionarily distant MIP sequences. We show that two histidines and a glutamic acid in the H-E-X-G-H motif and a glutamic acid 25 residues from the second histidine are essential for MIP functionin vivo.In contrast, C131 and C581 are important for protein stability but are not required for activityin vivoorin vitro.These findings are consistent with MIP being a metallopeptidase.
Modeling Balance of Plant Components for a PEM Fuel Cell

To integrate a fuel cell into a vehicle platform many subsystems must be engineered to support the electrical power production of the fuel cell plant. These subsystems include the control of fuel and air supply as well as managing thermal and water throughput in the fuel cell stack. For the fuel cell plant to operate at optimum performance, one must examine the individual components that make up the “balance of plant” of the fuel cell system. Specifically, the power used to run the system must be scrutinized with the power produced by the system. Knowing how individual balance of plant components perform is the first step in design and optimization studies, as well as automated control system development. To address these issues, this paper examines how balance of plant components and subsystems affect parasitic power consumption, fuel cell power production, membrane hydration, hydrogen usage, and water production.Copyright © 2006 by ASME
Emergency magnetic resonance imaging of cervical spinal cord injuries: clinical correlation and prognosis.

Objective The goal of this study was to determine the prognostic and clinical value of magnetic resonance imaging (MRI) performed within hours after cervical spinal cord injuries in human patients. Methods Fifty-five patients with acute cervical vertebral column and spinal cord injuries underwent MRI as part of their initial treatment at the University of Michigan Medical Center. All images were obtained within 21 hours after injury (mean, 7.8 h) and were interpreted by an attending neuroradiologist who was blinded to the clinical status of the patients. Neurological function at presentation and in long-term follow-up examinations was compared with MRI characteristics assessed immediately after the injury. Results The presence and rostrocaudal length of intra-axial hematoma, the rostrocaudal length of spinal cord edema, the presence of spinal cord compression, and spinal cord compression by extra-axial hematoma were each significantly associated with poor neurological function at presentation and in long-term follow-up examinations. Although the best single predictor of long-term improvement in neurological function was the neurological function at presentation, four MRI characteristics, i.e., the presence of intra-axial hematoma, the extent of spinal cord hematoma, the extent of spinal cord edema, and spinal cord compression by extra-axial hematoma, provided significant additional prognostic information. MRI data demonstrated spinal cord compression for 27 of 55 patients (49%), leading to emergency surgery. Among patients who underwent imaging after restoration of normal vertebral alignment using closed cervical traction, 13 of 26 (50%) underwent emergency surgery for treatment of persistent, MRI-demonstrated, spinal cord compression. Conclusion Emergency MRI after spinal cord injury provides accurate prognostic information regarding neurological function and aids in the diagnosis and treatment of persistent spinal cord compression after vertebral realignment.
A negative electroretinogram (ERG) in a case of probable multiple system atrophy (MSA)

Recent articles have described negative ERGs in a small number of patients with cerebellar degeneration. Five of the previously reported seven cases were hereditary (2/5 had spinocerebellar ataxia-1 (SCA-1) gene mutations) and the other two were sporadic. We report a negative ERG in a case of cerebellar degeneration that differs significantly from earlier cases. The 65-year-old man had a 5-year history of ataxia, unsteady gait, orthostatic hypotension, and bladder and erectile dysfunction, with no family history of neurological or retinal disease. Visual acuity was 20/30 OD, 20/40 OS, but reportedly was never 20/20. His fundus exam showed optic nerve pallor, but otherwise was normal. Visual fields had enlarged blind spots but no central scotomas. Autofluorescence was normal. Photopic flash and 30-Hz ERG responses were normal. Rod b-waves were reduced and delayed. Standard flash a-waves were normal, but the b-waves were smaller than the a-waves. Blood tests were negative for Leber's hereditary optic neuropathy, dominant optic atrophy, and for expansions in SCA genes including SCA-1. This is only the third reported case of sporadic ataxia with a negative ERG. The patient's prominent autonomic dysfunction differs from the previous cases, and meets the clinical criteria for probable multiple system atrophy (MSA). This introduces another possible diagnosis in cases of negative ERGs with ataxia, and suggests that the visual system may be affected in MSA.
Complex chemistry of hydrous chromium(III) oxide sol formation

Abstract Complex solution chemistry associated with formation and growth of hydrous chromium(III) oxide particles of narrow size distribution was investigated. The sols were prepared by heating dilute solutions of chromium(III) salts in the presence of sulfate ions. Upon removal of sol particles by filtration, complex solute species present in the electrolyte medium were separated and characterized using radio-paper electrophoresis. The results indicate that two solute species are involved in solid formation, and that multi-component equilibria are established. The effects of anion concentration and temperature are also discussed.
Phononics: colloidal crystals go hypersonic.

Hypersonic phononic crystals provide a wealth of opportunities to reflect, focus and localize high-frequency acoustic waves. Using colloidal crystals for this purpose provides opportunities for simplified fabrication and flexible tuning of the properties.
Paleobotany and Palynology of the Bristol Hill Coal Member (Bond Formation) and Friendsville Coal Member (Mattoon Formation) of the Illinois Basin (Upper Pennsylvanian)

Late Pennsylvanian coal swamps of the Illinois Basin were dominated by Psaronius tree ferns with a spatially heterogeneous distribution of medullosan pteridosperms (subdominant), calamites, sigillarian lycopsids, and cordaites. Miospore and coal-ball plant assemblages from the Missourian-age Bristol Hill Coal Member (Bond Formation) and Friendsville Coal Member (Mattoon Formation) of southeastern Illinois were quantified to analyze vegetational patterns in Late Pennsylvanian peat swamps and to compare vegetational composition of the coals. In the Bristol Hill Coal (95 coal balls, 2613 cm 2 coalball peels), tree ferns are dominant (75.6%), followed by pteridosperms (11.5%), lycopsids (10.6%), sphenopsids (0.6%), small ferns (1.6%), and cordaites (0.1%)
Shocking Numbers and Graphic Accounts: Quantified Images of Drug Problems in the Print Media

This paper examines how journalists and graphic artists in the national print media used statistical results from annual surveys of student drug use to construct quantified claims about a cocaine epidemic and other drug problems in 1986 and in subsequent years. Editorial and creative decisions entailed in transforming modest yearly changes in time-series data into a dramatic graphic image of “a coke plague” early in 1986 are reconstructed. The changing character of quantified images in the print media during the summer and fall of 1986 provides additional insights into how the rise and decline of a media “feeding frenzy” altered the claims-making activity of media workers. Finally, a recent case of the construction of a “new” drug problem on the eroding foundation of the cocaine epidemic is presented. The paper concludes with a discussion of how competitive conditions in the journalistic arena affect the production and distortion of quantified images of drug problems.
D1 dopamine receptor mediates dopamine-induced cytotoxicity via the ERK signal cascade

Postsynaptic striatal neurodegeneration occurs through unknown mechanisms, but it is linked to high extracellular levels of synaptic dopamine. Dopamine-mediated cytotoxicity of striatal neurons occurs through two distinct pathways: autoxidation and the D1 dopamine receptor-linked signaling pathway. Here we investigated the mitogen-activated protein kinase (MAPK) signaling pathways activated upon the acute stimulation of D1 dopamine receptors. In SK-N-MC neuroblastoma cells, endogenously expressing D1 dopamine receptors, dopamine caused activation of phosphorylated (p-)ERK1/2 and of the stress-signaling kinases, p-JNK and p-p38 MAPK, in a time- and dose-dependent manner. Selective stimulation of D1 receptors with the agonist SKF R-38393 caused p-ERK1/2, but not p-JNK or p-p38 MAPK activation, in a manner sensitive to the receptor-selective antagonist SCH 23390, protein kinase A inhibition (KT5720), and MEK1/2 inhibition (U0126 or PD98059). Activation of ERK by D1 dopamine receptors resulted in oxidative stress and cytotoxicity. In cells transfected with a catalytically defective mutant of MEK1, the upstream ERK-specific kinase, both dopamine- and SKF R-38393-mediated cytotoxicity was markedly attenuated, confirming the participation of the ERK signaling pathway. Cell fractionation studies showed that only a small amount of p-ERK1/2 was translocated to the nucleus, with the majority retained in the cytoplasm. From coimmunoprecipitation studies, p-ERK was found to form stable heterotrimeric complexes with the D1 dopamine receptor and beta-arrestin2. In cells transfected with the dominant negative mutant of beta-arrestin2, the formation of such complexes was substantially inhibited. These data provide novel mechanistic insights into the role of ERK in the cytotoxicity mediated upon activation of the D1 dopamine receptor.
Lattice dynamics of NdSb

Phonon dispersion curves for NdSb obtained by inelastic-neutron-scattering techniques have been analyzed on the basis of an axially symmetric force-constant model, a simple shell model, and a screened Coulomb force model. The last model gave the best fit to the experimental data. Various physical properties such as the effective ionic charges, the tetragonal distortion due to the magnetoelastic effect, and the Stark broadening of the transition between the crystal-field levels have been calculated from the model, and the results have been found to be in good agreement with experimental observations.
The public intellectual trope in the United States

This article takes the “public intellectual” trope as a theoretical case study, and traces how it has been used in the elite public sphere of the contemporary United States since its coining in 1987. The analysis challenges the notion that the “public intellectual” is primarily about broad democratic publics. It documents instead how the trope is used to frame meaning and practice within specific intellectual publics, namely science, higher education, and journalism. By focusing on the play of tropes around the “public intellectual” and examining the authoritative cultural members who use the trope, the trope analysis identifies principles and strategies under contest in the journalistic, academic, and political fields of the contemporary United States.
Superfluid helium three in aerogel

We report measurements of the superfluid density and transition temperature of3He confined within 98.2% open aerogel. Both the superfluid fraction and the temperature at which the superfluid is manifested are suppressed strongly from their bulk values. The results suggest that the aerogel reduces the order parameter by a mechanism other than as a diffusely scattering surface.
The spin Hamiltonian for electron spin resonance of radicals in doublet states: calculations in the energy weighted maximum overlap model

The parameters of a spin Hamiltonian for the description of electron spin resonance spectra of oriented radicals, trapped in crystalline solids, are described within an approximate electron propagator framework. Only radicals in doublet states are considered, so that the pertinent parameters are the g-tensor, the hyperfine interaction tensor and the quadrupole interaction tensor. Various semiempirical approaches are discussed and a number of calculations are carried out in the energy weighted maximum overlap model (e. w. m. o.). Particularly satisfactory results were obtained for the g-tensors and ‘central’ atom hyperfine interaction tensors.
Peptides in ionic solutions: A comparison of the Ewald and switching function techniques

The methodological dependence of observed ion–peptide associations in molecular dynamics simulations is investigated. We compare the results from several simulations of a pentapeptide in explicit solvent and salt ions which differ in the their treatment of the long ranged electrostatic interactions. Results for both the Ewald and switching function techniques are presented. It was found that there were important differences between the two methods for the water dipole–dipole temporal and spatial correlations, total dipole moment fluctuations, and self‐diffusion constants. Electrostatic potentials calculated in the region of the peptide are also used to illustrate the large differences that can arise from different treatments of the electrostatic interactions. It appears that the switching function distorts the molecular electrostatic potential experienced by the salt ions to such a degree that their behaviour becomes highly dependent on the initial conditions. In summary, the use of a switching function is not recommended for the simulation of ions and their interactions with biomolecules.
Electron impact studies of some cyclic hydrocarbons

Abstract The formation of negative ions by collisions of low-energy electrons with cyclooctatetraene, biphenylene, triphenylene, fluorene, indene, acenaphthene, acenaphthylene, and fluoranthene was examined in the gas phase under single collision conditions. Long-lived negative ions (τ > 1 μsec) were observed in the cases of cyclooctatetraene and acenaphthylene at approximately zero energy with mean lifetimes of 6.4 and 88 μsec, respectively. The energy breadth of the negative ion resonances for these ions was equal to the electron energy resolution, and thus the measured lifetimes are averaged over the width of the resonance. Fluoranthene captures slow electrons with a maximum in the cross section at 0.2 eV, and the width of the resonance is approximately 0.4 eV. The lifetime was found to decrease from 180 μsec at ∼ eV to 80 μsec at ∼ 1.0 eV. Energy-loss processes were observed using the SF6 scavenger technique in biphenylene and triphenylene at electron energies of 2.15 and 2.35 eV, respectively, and are attributed to compound negative ion states.
The influence of gender labelling on preschoolers' gender constancy judgements

Criticism of traditional gender constancy assessment has focused on the unrealistic nature of the perceptual stimuli used to elicit gender judgements. Recent modifications of the traditional task have made use of more realistic perceptual information, but have also altered the linguistic structuring of constancy judgement requests. Subsequent improvements in preschooler performance have been attributed solely to changes in perceptual stimuli. This study examines the possibility that changes in linguistic structuring also affect performance in significant ways. Thirty-nine preschoolers completed one of two versions of a modified gender constancy task; in one version pictured changes in appearance and activity were accompanied by gender labelling (approximating traditional tests). The second version was identical to the first except that gender labels were eliminated (as in recent modified tasks). Performance was significantly improved when labels were omitted. Implications for interpreting preschooler performance under modified task conditions are discussed.
Coronal activity below 2 solar radii - 1980 February 15-17

Coronal observations concerning the area between the solar surface and 2.0 solar radii can now be conducted by making use of a new ground-based K-coronameter and a prominence monitor on Mauna Loa in Hawaii. Observations made by the K-coronameter on three consecutive days surrounding the eclipse of 1980 February 16 show that the solar corona was very active during this time. Definite changes occurred between each day's observations. During one period of K-coronameter observations (1980 February 15) a coronal transient was observed to move through the coronameter's field of view. A description is presented of the general changes which occurred in the corona during this period, taking into account the coronal transient observed by the prominence monitor and K-coronameter. The most important aspects of these new observations pertain to the relationship between the H alpha prominence and the surrounding coronal material.
Multi-structural variational transition state theory. Kinetics of the 1,4-hydrogen shift isomerization of the pentyl radical with torsional anharmonicity

We present a new formulation of variational transition state theory (VTST) called multi-structural VTST (MS-VTST) and the use of this to calculate the rate constant for the 1,4-hydrogen shift isomerization reaction of 1-pentyl radical and that for the reverse reaction. MS-VTST uses a multi-faceted dividing surface and provides a convenient way to include the contributions of many structures (typically conformers) of the reactant and the transition state in rate constant calculations. In this particular application, we also account for the torsional anharmonicity. We used the multi-configuration Shepard interpolation method to efficiently generate a semi-global portion of the potential energy surface from a small number of high-level electronic structure calculations using the M06 density functional in order to compute the energies and Hessians of Shepard points along a reaction path. The M06-2X density functional was used to calculate the multi-structural anharmonicity effect, including all of the structures of the reactant, product and transition state. To predict the thermal rate constant, VTST calculations were performed to obtain the canonical variational rate constant over the temperature range 200–2000 K. A transmission coefficient is calculated by the multidimensional small-curvature tunneling (SCT) approximation. The final MS-CVT/SCT thermal rate constant was determined by combining a reaction rate calculation in the single-structural harmonic oscillator approximation (including tunneling) with the multi-structural anharmonicity torsional factor. The calculated forward rate constant agrees very well with experimentally-based evaluations of the high-pressure limit for the temperature range 300–1300 K, although it is a factor of 2.5–3.0 lower than the single-structural harmonic oscillator approximation over this temperature range. We anticipate that MS-VTST will be generally useful for calculating the reaction rates of complex molecules with multiple torsions.
On the design of liquid metal divertors

The divertor technology has become the focus of concern for prospective steady state tokamak reactors. The imposed heat flux and particle flux conditions cast doubt on the feasibility of any solid surface divertor. The aim of this work is to evaluate the existing concepts of liquid metal divertors from the physics, engineering, and safety points of view. Lithium metal is found to relatively suffer from a large tritium inventory that may develop in the form of solid hydride LiH, in addition to the fire hazard potential. Gallium does not form hydride within the temperature range of interest and is inactive with oxygen, therefore it is considered a more favorable metal. The flowing film and pool type divertors are found to suffer from the possible blistering erosion and resulting plasma contamination. The self-cooled liquid metal film divertor suffers also from a linear MHD instability, in addition to complicating factors such as the variation of the liquid metal electric property, dynamics of halo current, and the possible incompatibility with the insulator coating. The liquid gallium droplet curtain divertor appears to be the most feasible and roust, but its high temperature vapor is corrosive to most structural materials.
Spectral linewidth narrowing in a strongly coupled atom-cavity system via squeezed-light excitation of a ‘‘vacuum’’ Rabi resonance

The system consisting of a two-level atom coupled strongly to a cavity mode behaves as a two-state system when excited near one of the ``vacuum'' Rabi resonances. With finite-bandwidth squeezed light incident upon the cavity and tuned to one of these resonances, we show that it is possible to realize a two-state system coupled to a squeezed vacuum. This system exhibits subnatural linewidths in the emitted spectra, as described by Gardiner [Phys. Rev. Lett. 56, 1917 (1986)] in a study of spontaneous emission of a two-level atom in a squeezed vacuum, but requires that only a single cavity mode be subject to squeezing rather than the entire three-dimensional vacuum.
Si, Zn-Modified Tricalcium Phosphates: A Phase Composition and Crystal Structure Study

Tricalcium phosphate modified by silicon and zinc was synthesized as a candidate for resorbable temporal bone implant having a controlled solubility and improved biocompatibility. Since Si and Zn are essential trace elements with stimulatory effects on bone formation, Si,Znmodified tricalcium phosphate can also promote bone formation. From XRD and ICP analyses, it was shown that up to 10 mol% Si and Zn can be incorporated in the tricalcium phosphate lattice without formation of a second phase. Changes in lattice parameters and unit volume of TCP as calculated by Rietveld refinement analysis indicate that Si and Zn substitute for P and Ca respectively.
Quantum dynamics of a nanomagnet driven by spin-polarized current

A quantum theory of magnetization dynamics of a nanomagnet as a sequence of scatterings of each electron spin with the macrospin state of the magnetization results in each encounter a probability distribution of the magnetization recoil state associated with each outgoing state of the electron. The quantum trajectory of the magnetization contains the average motion tending in the large spin limit to the semiclassical results of spin transfer torque and the fluctuations giving rise to a quantum magnetization noise and an additional noise traceable to the current noise.
Markov Chain Modeling of Pyelonephritis-Associated Pili Expression in Uropathogenic Escherichia coli

Pyelonephritis-associated pili (Pap) expression in uropathogenic Escherichia coli is regulated by a complex phase variation mechanism involving the competition between leucine-responsive regulatory protein (Lrp) and DNA adenine methylase (Dam). Population dynamics of pap gene expression has been studied extensively and the detailed molecular mechanism has been largely elucidated, providing sufficient information for mathematical modeling. Although the Gillespie algorithm is suited for modeling of stochastic systems such as the pap operon, it becomes computationally expensive when detailed molecular steps are explicitly modeled in a population. Here we developed a Markov Chain model to simplify the computation. Our model is analytically derived from the molecular mechanism. The model presented here is able to reproduce results presented using the Gillespie method, but since the regulatory information is incorporated before simulation, our model runs more efficiently and allows investigation of additional regulatory features. The model predictions are consistent with experimental data obtained in this work and in the literature. The results show that pap expression in uropathogenic E. coli is initial-state-dependent, as previously reported. However, without environment stimuli, the pap-expressing fraction in a population will reach an equilibrium level after approximately 50-100 generations. The transient time before reaching equilibrium is determined by PapI stability and Lrp and Dam copy numbers per cell. This work demonstrates that the Markov Chain model captures the essence of the complex molecular mechanism and greatly simplifies the computation.
A mathematical model that mimics the bursting oscillations in pancreatic β-cells

Abstract A revised version of Rossler's dual principle is used to realize a geometrical mechanism for chaos generation. The resulting mathematical model is a singularly perturbed system with three time scales. The system is then used to mimic the glucose-induced electrical activity of pancreatic β-cells.
Design of a projection TV zoom lens with the grin lens and aspherical surface

The optical design of projection zoom lens by using special surfaces, such as aspherical surface and grin lens are presented in this paper. The techniques to approach the special design from all-spherical design are described. The results show that the use of grin lens and glass modeling asphere can effectively reduce the element number and the image quality is kept meanwhile.
Structural characterization of III-nitride materials and devices

The electron microscope provides a wide range of techniques that are very well suited for structural characterization of nanophotonic materials and devices. High-resolution electron microscopy (defect identification and strain field analysis), Z-contrast imaging in the scanning transmission electron microscope (cation distribution), convergent-beam electron diffraction (local lattice parameter and strain), and off-axis electron holography (internal electrostatic fields), represent powerful complementary approaches for distinguishing between the often-competing effects of growth conditions and compositional differences. These various TEM techniques have been used separately or in tandem in our recent collaborative studies of III-nitride heterostructures and nanostructures, where lattice mismatch, compositional inhomogeneities and phase separation were all important considerations that can possibly impair the structural quality of the final material and/or device. Representative applications that illustrate the prospects and some of the problems include the following: i) relaxed InN quantum dots; ii) deep-UV-emitting AlGaN quantum wells; iii) near-UV light-emitting diodes based on InN/GaN quantum wells; and iv) blue-green LEDs based on GaN quantum-dot superlattices.
Adolescents Coping with Poverty-Related Family Stress: Prospective Predictors of Coping and Psychological Symptoms

Examined prospective associations among poverty-related family stress, coping, involuntary stress reactivity, and psychological symptoms in a sample of 79 rural, low-income adolescents. Poverty-related family stress predicted adolescents’ anxious/depressed and aggressive behavior 8 months later, controlling for prior symptoms. Coping interacted with initial symptoms and involuntary stress reactivity to predict changes in symptoms over time, showing that primary and secondary control coping were most strongly associated with changes in symptoms for adolescents with low initial symptoms and involuntary stress reactivity. The only significant predictor of coping over time was prior coping, suggesting that coping is not symptom-driven and may be somewhat trait-like. Implications for interventions and additional research are offered.
(−)-3,7-Dioxo-5β-cholanic acid: dual hydrogen-bonding modes in a diketonic bile-acid derivative

The asymmetric unit of the title compound, C(24)H(36)O(4), contains three molecules, all differing in their side-chain conformations and all linked by hydrogen bonding confined entirely within a three-molecule block. One connection is of the acid-to-ketone type [O...O = 2.7055 (19) Angstrom and O-H...O = 180 degrees ] and the other involves carboxyl pairing [O...O = 2.6485 (18) and 2.6598 (18) Angstrom, and O-H...O = 168 and 174 degrees ]. Numerous intermolecular C-H...O close contacts connect neighbouring molecules.
Application of the transmission line equivalent circuit model to the analysis of the PN junction admittance under d.c. bias

Abstract Exact non-equilibrium one-energy-level numerical solutions of the admittance of a p+n junction are obtained from the nonuniform transmission line equivalent circuit model. Capacitance and conductance curves for equilibrium and reverse-biased gold-doped silicon diode are calculated using experimental values of emission and capture rates. Comparisons between theoretical and experimental frequency dependences of the admittance using new experimental capture rates show good agreements over a wide range of reverse bias.
Studies of glucuronidation and sulfation in tumor-bearing rats.

Abstract Rats bearing subcutaneous Walker 256 carcinoma or intramuscular Reuber H-35 hepatoma were tested for their ability to metabolize 14 C- p -nitrophenol into its sulfate and glucuronide. Amounts of p -nitrophenyl glucuronide (PNPGA) and p -nitrophenyl sulfate (PNPS) excreted by the Walker hosts did not differ significantly from those excreted by the controls. Hepatoma hosts, compared with controls, excreted comparable amounts of PNPS but significantly higher amounts of PNPGA. To clarify the basis for the changes in the conjugate levels in urine of the hepatoma hosts, sulfotransferase and glucuronyl transferase activities of the hepatoma and of host and control livers were assayed. The hepatoma possessed significantly higher glucuronyl transferase activity than either type of liver, but had a very low sulfotransferase activity. Microsomal glucuronyl transferase of the hepatoma obeyed Michaelis-Menten kinetics; K m value for p -nitrophenol is 0.22 mM. Liver transferase(s) gave different and irregular kinetics, suggesting qualitative differences between the transferases of the hepatoma and liver.
Ethical dilemmas: The organization of family caregiving for the elderly

Abstract Analysis of sixty ethnographic interviews on the meaning of activity in family caregiving for frail community elderly generated a model of caregiving as a daily round of ethical dilemmas. Five ethical themes were derived from the data. The ethical maxim “above all do no harm” led to prominent patterns of tension within the principle of beneficence and between the principles of autonomy and beneficence. Justice was the principle most often perceived to be violated. The data suggest that professionals who work with family caregivers should seek to understand the caregiver's ethical framework in order to bring about an optimum therapeutic relationship in long term care.
Interrelationships Among Aphids, Tarnished Plant Bugs, and Alfalfas

Both aphid-resistant and aphid-susceptible alfalfa varieties, Medicago sativa L., were more attractive to the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), in cages containing spotted alfalfa aphids, Therioaphis maculata (Buckton), than in cages lacking aphids. However, plant bug increase on the aphid-resistant variety 'Kanza' was only 17.6%, compared with 123.2% for the aphid-susceptible variety 'Alfa.' In the absence of aphids, attractiveness of the 2 varieties was similar. Rate of tarnished plant bug mortality was markedly lower in cages containing aphids than it was in control cages. Tarnished plant bugs were observed feeding on pea aphids ( Acyrthosiphon pisum (Harris), and spotted alfalfa aphids. When caged on an aphid-susceptible alfalfaclone, adult plant bugs apparently destroyed an average of 2.4 spotted alfalfa aphid and 2.1 pea aphid nymphs per day. Alfalfa sprayed with a 10% sucrose solution attracted significantly more (72%) bugs than did unsprayed alfalfa. Bug increases from spraying were 33 and .143% for 'KSl0' and Alfa, respectively.
TRACE CONCENTRATIONS OF HALOTHANE IN HUMAN BREAST MILK

SUMMARY Halothane concentrations of 2 p.p.m. have been found in the breast milk of a lactating, practising anaesthetist. This concentration was consistent with the operating theatre environment. The authors feel that, in spite of the limited scope of the study, this is an additional reason for the elimination of waste anaesthetic agents from the operating theatre.
Communications: Yield Characteristics of the Free‐Living Nematode Panagrellus redivivus in Different Culture Media

Abstract The nematode Panagrellus redivivus was cultured in media composed of wheat flour, oatmeal, or cornmeal. Total yield of nematodes in wheat flour (4,000 Mg/100 cm2) was significantly greater than in oatmeal (I, 506 mg/ 100 cm2) or cornmeal (283 mg/ 100 cm2). Production of nematodes stopped after day 20 in cornmeal, day 33 in oatmeal, and day 53 in wheat flour. A second rearing trial was conducted with wheat flour, cottonseed meal, or ground shrimp feed as culture media. Wheat flour provided a significantly greater total yield (4,240 Mg/100 cm2) and longer production period (38 d) than either cottonseed meal (1,979 mg/100 cm and 28 d) or ground shrimp feed (959 mg/ 100 cm and 15 d). Addition of yeast during initial media preparation had no effect on nematode yield. The addition of yeast on a weekly basis to wheat flour medium gave a significantly greater yield of nematodes than did untreated wheat flour.
Debt to Society: Asset Poverty and Prisoner Reentry:

Every year, millions of people exit American jails and prisons and attempt to reintegrate into society. Ex-offenders face many obstacles during the transition. Scholars contend that securing employment is central to a successful transition. A job that allows an ex-offender to earn an income above the poverty line is especially significant, recent studies have shown. Consequently, many prisoner reentry initiatives are focused on expanding employment opportunities for ex-offenders. However, the almost exclusive emphasis on employment as the measurement of economic well-being is short-sighted because it ignores the importance of financial education and asset ownership. Prisoner reentry programs should include an emphasis on financial education in addition to an emphasis on employment as a means of reducing recidivism rates and improving the economic well-being of the ex-offenders and receiving communities. The paper concludes with a discussion of policy implications.
The permuted generator hypothesis for the origin of a genetic code

Protocells had no known means of ensuring that their randomly collected proteins would be duplicated. A possible, albeit inexact, mechanism for protein synthesis in a primitive t-RNA is presented, whereby an oligonucleotide (12 units) in a circular configuration is able to align a generator site with amino acid discriminator sites. In this way, unique anticodons could be specified for each site and replication could occur.
Nephrology Pharmaceutical Care Preceptorship: A Programmatic and Clinical Outcomes Assessment

OBJECTIVE:The University of Pittsburgh Nephrology Pharmaceutical Care Preceptorship (NPCP) program was conceived to acquaint health system pharmacists with the pharmacotherapeutic management of dialysis patients, enhance the delivery of pharmaceutical care, and improve clinical outcomes through the development of specialized professional skills. A survey designed to determine the impact of the NPCP program was sent to all 145 participants of the program.METHODS:The survey, designed to collect demographic information and data about the participants' practice sites, professional activities prior to and after the completion of the program, and markers of disease status, was mailed to all participants in September 1997. The 96 respondents (66.2%) were involved in a wide variety of clinical practices; inpatient management of peritoneal dialysis, hemodialysis, or renal transplant patients were most commonly reported.RESULTS:More than 80% of the participants believed that the educational content of the NPCP prog...
Performance Comparison of MPI Implementations over InfiniBand, Myrinet and Quadrics

In this paper, we present a comprehensive performance comparison of MPI implementations over Infini-Band, Myrinet and Quadrics. Our performance evaluation consists of two major parts. The first part consists of a set of MPI level micro-benchmarks that characterize different aspects of MPI implementations. The second part of the performance evaluation consists of application level benchmarks. We have used the NAS Parallel Benchmarks and the sweep3D benchmark. We not only present the overall performance results, but also relate application communication characteristics to the information we acquired from the micro-benchmarks. Our results show that the three MPI implementations all have their advantages and disadvantages. For our 8-node cluster, InfiniBand can offer significant performance improvements for a number of applications compared with Myrinet and Quadrics when using the PCI-X bus. Even with just the PCI bus, InfiniBand can still perform better if the applications are bandwidth-bound.
Decline in Renal Hemodynamic Function in Aging SHR: Role of Androgens

Although men and male rats are at increased risk for age-related renal and cardiovascular disease compared with women and female rats, the mechanisms are unknown. However, castration of male normotensive rats protects against age-related glomerular sclerosis, and castration of spontaneously hypertensive rats (SHR) attenuates the age-related progression of hypertension to levels found in female SHR. The present study was performed to determine whether there are differences between male and female renal function in SHR with aging, and if so, the role that androgens play in the age-related changes in renal function in SHR. Renal hemodynamics, glomerular filtration rate (GFR), and proteinuria were measured in anesthetized male and female SHR aged 7 to 8, 14 to 15, and 30 to 32 weeks (n=5 to 7 per sex per age group). Studies were also performed in male SHR that had been castrated at 4 weeks of age and allowed to age to 7 to 8, 14 to 15, and 30 to 32 months of age (n=5 to 9 per age group). At 7 to 8 weeks of age when blood pressures are similar between male, female, and castrated male SHR, there were no differences in renal hemodynamics between male and female SHR. As the rats aged, mean arterial blood pressure increased in all groups and was higher in the intact male SHR than in females. Blood pressure in aging castrated males was similar to the pressure in aging female SHR. With advancing age, GFR in intact male SHR decreased by 20% to 30% at 14 to 15 and 30 to 32 weeks of age, respectively. Renal plasma flow (RPF) also tended to decrease in male SHR but not statistically so. There was no age-related reduction in GFR or RPF in female or castrated male SHR. With advancing age, renal vascular resistance (RVR) increased in all rats. RVR increased by 40% and 60% at 14 to 15 and 30 to 32 weeks in male SHR. In comparison, RVR increased by 20% and 40% in female SHR at similar ages. RVR in castrated male SHR was similar to RVR in females. The levels of urinary protein excretion increased with aging to 14 weeks in the male SHR, but in females and castrated males urinary protein excretion reached a plateau at 6 to 8 weeks that was maintained until 14 weeks of age and was approximately sixfold lower than in male SHR. These data suggest that androgens may play an important role in mediating the hypertension and the age-related alterations in renal function in the male SHR.
The Repertoire of Infidelity among Low-Income Men: Doubt, Duty, and Destiny

In an effort to explain the rise of unwed parenthood in the inner city over the past several decades, a large body of research has attributed the phenomenon in part to low-income men’s unwillingness to commit to long-term, monogamous relationships. A major limitation of these studies, however, is that virtually none attempt to understand relationship dissolution by comparing low-income inner-city men in monogamous and nonmonogamous long-term heterosexual relationships. Drawing from a convenience sample of thirty-eight low-income monogamous and nonmonogamous men, this article develops a typology of three cultural logics of action used by respondents to motivate behavior in relationships: doubt, duty, and destiny. These cultural logics help to explain how poverty influences sexual action; nevertheless, this typology supports an emerging literature demonstrating the ways in which the sexual “culture of poverty” is contingent, contradictory, indeterminate, and multivocal.
Idiopathic Fistula Formation in the Gastrointestinal Tract. An Unusual Cause of Malabsorption Associated with Jejunal Diverticulosis and Obliteration of the Peritoneal Cavity by Adhesions

Summary A patient is reported with severe malabsorption and inanition due to multiple fistulous tracts between the small bowel and colon and between adjacent loops of small bowel. Jejunal diverticulosis and idiopathic obliteration of the peritoneal cavity by old adhesions were also present. Only two other similar cases have been found in a review of the literature. The etiology of the fistulous tracts in these patients is unknown. However, in view of the dense adhesions and marked obliteration of the peritoneal cavity it is possible that the fistulas developed between the closely bound loops of bowel, possibly through inflamed diverticula. This unusual malabsorption syndrome should be suspected in patients presenting with the following findings: 1) rapid intestinal transit of food or barium in the absence of a past history of intra-abdominal disease; 2) normal small bowel mucosal pattern by x-ray and essentially normal biopsy; and 3) small intestinal diverticulosis. Although the fistulous tracts may fail to visualize on radiological examination of the upper GI tract, they should be readily demonstrable by barium enema.
Optimizing snake locomotion in the plane

We develop a numerical scheme to determine which planar snake motions are optimal for locomotory efficiency, across a wide range of frictional parameter space. For a large coefficient of transverse...
How to increase locking range of coupled oscillator cells without lowering Q

The locking-range and phase error caused by the random free-running frequency distribution in coupled oscillator phased arrays are studied. A design method based on coupling optimization is proposed to improve the oscillator locking-range and thereby reduce the phase error. A qualitative analysis and experimental results are presented to demonstrate the viability of this method for improving the fabrication tolerance of coupled oscillator phased arrays.
Modeling and automatic real-time motion control of wheeled mobile robots among moving obstacles: theory and applications

Addresses the interesting and difficult problem of real-time planning and efficient motion control of a rigid mobile robot to dynamically avoid obstacle(s) as the latter moves. Most techniques described so far in the literature deal with the simpler problem of generating (generally off-line) a path among stationary obstacles. For practical purposes, however, obstacles are not always static and most interesting environments are in general not known precisely and/or time varying. In particular, robots capable of manoeuvring among moving obstacles will be capable of accomplishing a much larger and more versatile class of tasks. The authors tackle this problem from a different angle and present a powerful real-time collision avoidance technique using complex potential functions and conformal mapping. Based on complex potential models, a feedback controller with constant robot curvilinear velocity is derived for the automatic guidance and motion control of the mobile robot. The goals of the velocity feedback are twofold: (1) lowering the overhead of the higher level decision-making control and placing it in the lower level motion control, (2) allowing the robot to smoothly rotate and translate with a constant curvilinear speed to account for the physical limitation of the robot device dynamics. The idea is to navigate through the environment using only sensory information, which makes the method insensitive to physical changes such as moving obstacles. At the heart of the technique is the exploitation of the powerful and fundamental tool of conformal mapping to derive the path solution for obstacles of arbitrary shapes. Finally application results are presented which indicate the potential value of the theory and methodology. >
Measurement foundations for multiattribute psychophysical theories based on first order polynomials

The class of first order polynomial measurement representations is defined, and a method for proving the existence of such representations is described. The method is used to prove the existence of first order polynomial generalizations of expected utility theory, difference measurement, and additive conjoint measurement. It is then argued that first order polynomial representations provide a deep and far reaching characterization of psychological invariance for subjective magnitudes of multiattributed stimuli. To substantiate this point, two applications of first order polynomial representation theory to the foundations of psychophysics are described. First, Relation theory, a theory of subjective magnitude proposed by Shepard
Ultra-Fast CPU Performance Prediction: Extending the Monte Carlo Approach

Performance evaluation of contemporary processors is becoming increasingly difficult due to the lack of proper frameworks. Traditionally, cycle-accurate simulators have been extensively used due to their inherent accuracy and flexibility. However, the effort involved in building them, their slow speed, and their limited ability to provide insight often imposes constraints on the extent of design exploration. In this paper, we refine our earlier Monte Carlo based CPI prediction model (Srinivasan et al., 2006) to include software assisted data-prefetching and an improved memory model. Software-based prefetching is becoming an increasingly important feature in modern processors but to the best of our knowledge, existing frameworks do not model it. Our model uses micro-architecture independent application characteristics to predict CPI with an average error of less than 10% when validated against the Itanium-2 processor. Besides accurate performance prediction, we illustrate the applications of the model to processor bottleneck analysis, workload characterization and design space exploration
Perceptions of grief among university students

Abstract Although research on grief has proliferated in recent years, few studies have attempted to examine the grief perceptions of people surrounding the bereaved. In this investigation, 123 undergraduates responded to an open-ended survey that assessed their perceptions of various aspects of grief, including physical and emotional features, time course, interpersonal impact, coping strategies, and methods of intervening. Results revealed that many students possess an understanding of the grief process. It is speculated that this understanding may stem from the heightened attention that the media and others have focused on death and dying in recent years, and may also be due to participants having personally experienced different forms of grief in their lives.