cssi/SciSciGPT-SciSciNet huggingface dataset:
Gastrointestinal dysfunction in Parkinson's disease

Gastrointestinal dysfunction is common and clinically important in patients with PD. Evidence continues to accumulate to indicate that these symptoms reflect, for the most part, the direct involvement of the gastrointestinal tract by the PD process. Gastrointestinal symptomatology may arise not only as a consequence of the effects of PD on skeletal muscles in the oropharynx, anorectum, and pelvic floor but also through the direct involvement of the autonomic and enteric nervous systems in the PD process. While many aspects of gastrointestinal dysfunction in PD continue to be delineated, therapeutic approaches to gut symptoms in this common disorder remain in their infancy. Gut involvement in PD can be seen to serve as a paradigm for gut-CNS interactions. The recent demonstration of neuropathologic abnormalities in the enteric nervous system analogous to those regarded as pathognomonic of the parkinsonian process in the CNS suggests that the enteric and central nervous systems may demonstrate parallel pathologic changes in a number of disease processes previously regarded as confined to the central and somatic nervous systems. In this way, the enteric nervous system may well serve as a more accessible "window" to a variety of degenerative neurologic disorders. With respect to PD itself, we can begin to relate both the neurologic and gastrointestinal manifestations of this disorder to defects at a number of levels (Table 1).
Assessment of hemodynamic tolerance from a 24-hour intravenous infusion of fenoldopam mesylate in congestive heart failure

To determine the maintenance of pharmacodynamic effects of fenoldopam mesylate, a dopamine-1 agonist, the invasive hemodynamic profiles of 33 patients with New York Heart Association functional class III to IV congestive heart failure were examined. Fenoldopam mesylate was initiated at 0.1 micrograms/kg/min and titrated to a cardiac index greater than or equal to 25% above baseline. Upon achievement of optimal hemodynamics, maintenance infusion was begun (mean dose 0.6 micrograms/kg/min). Fenoldopam mesylate (baseline vs maximal effect) decreased systemic vascular resistance by 37% (p less than 0.001), left ventricular filling pressure by 16% (p less than 0.05) and mean arterial pressure by 11% (p less than 0.05), with an associated augmentation in cardiac index and stroke volume index by 27% (p less than 0.001). Attenuation of hemodynamic effect (maximal effect vs time) was noted in cardiac index (14% p less than 0.001), systemic vascular resistance (13% p less than 0.05) and stroke volume index (13% p less than 0.05). None of the parameters exhibited complete attenuation to baseline values. Fenoldopam mesylate improves cardiac output and lowers systemic vascular resistance with relative attenuation of pharmacodynamic effect during a 24-hour intravenous infusion.
Molecular-dynamics simulation of the static pair-pair correlation function for classical fluids

We have used a molecular-dynamics simulation to calculate the first seven nonzero Legendre coefficients, ${\mathit{Q}}^{(\mathit{l})}$(r,r'), of the static pair-pair correlation function Q(r,r'). The interaction potential was taken to be Lennard-Jones. The simulations were done at two different values of density and temperature, one coinciding with that of liquid argon near its triple point and the other with liquid argon at 181.0 K. Q(r,r') can be expressed in terms of two, three-, and four-body distribution functions. We use the Kirkwood superposition approximation to estimate the three-body contribution to Q(r,r'). We argue that at low densities the three-body correlations are substantially more important than the four-body correlations. The three-body part of the l=4 and 6 coefficients emphasizes configurations composed of nearest-neighbor triplets with internal angles of approximately 90\ifmmode^\circ\else\textdegree\fi{} and 60\ifmmode^\circ\else\textdegree\fi{}, respectively. We find that the l=6 coefficient shows a dramatic increase in structure at elevated density. Furthermore, this coefficient exhibits nearly periodic oscillations in its off-diagonal structure. Directions for future work are given.
Electrical and Optical Properties of Permalloy Oxide grown by dual ion beam sputtering.

Electrical and Optical measurements were carried out on permalloy oxide (PyO) thin films made by reactive dual ion beam sputtering at room temperature. VSM measurements at room temperature and 15 Kelvin did not reveal any magnetic moment in 120 nm thick films. The optical refraction and extinction spectra from 200-1000 nm were determined from ellipsometry measurements using a Cody-Lorentz model and provided in a reproducible method to determine the film thickness of PyO films on different substrate materials. PyO is transparent above 700 nm and is strongly absorbing below 500 nm. The resistivity values of PyO samples sputtered at room temperature depend on the oxygen flow rate and is approximately 4E3 Ohm cm for films prepared at 10 sccm. The resistivity of PyO decreases as a function of temperature. The dielectric constant is strongly frequency dependent, decreasing from 500 at 500 Hz to 10 at 1 MHz.
Improved hurricane active/passive simulated wind vector retrievals

Microwave scatterometers are the standard for satellite ocean vector winds (OVW) measurements, and they provide the major source of global ocean surface winds observations for scientific and operational applications. A major challenge for Ku-band scatterometry missions is to provide reliable retrievals in the presence of precipitation, particularly in extreme ocean wind events that are usually associated with intense rain. This paper explores the advantages of combining dual frequency (C- and Ku-band) scatterometer measurements and passive microwave observations to improve high wind speed retrievals. For this study, a conceptual design proposed by the Jet Propulsion Laboratory for a Dual Frequency Scatterometer (DFS) to fly onboard the future Japan Aerospace Exploration Agency (JAXA) GCOM-W2 mission with the Advanced Microwave Scanning Radiometer (AMSR) was adopted. A computer simulation that combines the DFS and AMSR measurements was used to develop an artificial neural network OVW retrieval algorithm. The Weather Research and Forecasting (WRF) numerical weather model of Hurricane Katrina (2005) was used as the nature run (surface truth), and simulated OVW retrievals demonstrate that this new technique offers a robust option to extend the useful wind speed measurements range beyond the current operating scatterometers for future satellite missions.
A Novel Cardiolipin-remodeling Pathway Revealed by a Gene Encoding an Endoplasmic Reticulum-associated Acyl-CoA:Lysocardiolipin Acyltransferase (ALCAT1) in Mouse

Cardiolipin is a major membrane polyglycerophospholipid that is required for the reconstituted activity of a number of key mitochondrial enzymes involved in energy metabolism. Cardiolipin is subjected to remodeling subsequent to its de novo biosynthesis to attain appropriate acyl composition for its biological functions. Yet, the enzyme(s) involved in the remodeling process have not been identified. We report here the identification and characterization of a murine gene that encodes an acyl-CoA:lysocardiolipin acyltransferase 1 (ALCAT1). Expression of the ALCAT1 cDNA in either insect or mammalian cells led to a significant increase in acyl-CoA:monolysocardiolipin acyltransferase and acyl-CoA: dilysocardiolipin acyltransferase activities that exhibited a dependence upon ALCAT1 enzyme levels. The recombinant ALCAT1 enzyme recognizes both monolysocardiolipin and dilysocardiolipin as substrates with a preference for linoleoyl-CoA and oleoyl-CoA as acyl donors. In contrast, no significant increases in acyltransferase activities by the recombinant ALCAT1 were detected against either glycerol-3-phosphate or a variety of other lysophospholipids as substrates, including lysophosphatidylcholine, lysophosphatidylethanolamine, and lysophosphatidylserine. Immunocytohistochemical analysis showed that the ALCAT1 enzyme is localized in the endoplasmic reticulum, which is supported by a significant ALCAT activity in isolated liver and heart microsomes. Northern blot analysis indicates that the mouse ALCAT1 is widely distributed, with the highest expression in heart and liver. In support of a role for ALCAT1 in maintaining heart function, the ALCAT1 gene is conserved among different species of vertebrates, but not in non-atrium organisms. ALCAT1 represents the first identified cardiolipin-remodeling enzyme from any living organism; its identification implies a novel role for the endoplasmic reticulum in cardiolipin metabolism.
Metamaterial Spheroidal Cavity to Enhance Dipole Radiation

Metamaterials have been considered for their potential to improve the radiation characteristics of sources. A novel geometry consisting of a semioblate spheroidal cavity containing two layers, one made of DPS and the other made of DNG metamaterial, and built underneath an aperture in infinite metallic plane is considered. An exact analytical solution is obtained and its numerical evaluation demonstrates a significant improvement of the directive radiation of a dipole source, with the appropriate combination of the ordinary double positive (DPS) and DNG layers.
Computer personnel research group, 1966 survey of test use in computer personnel selection

The growth in the number of Programmers has been spectacular; from an estimated 6,000 in 1954 and an estimate of 50,000 in 1963 (Ref. 1), it has increased to a present population of 120,000-150,000 Programmers and some 50,000 Systems Analysts. This number is expected to jump to 400,000 Programmers and Systems Analysts by 1970 (Ref. 2). It is obvious then, that the problem of attracting, selecting, and hiring for this future growth in the computer industry will become more critical each year. As a step in planning further research in this field, information on current selection criteria has been obtained by use of a survey sent to computer installation managers in both the United States and Canada, the results of which make up this report.
Comparison of the protective effects of verapamil, diltiazem, nifedipine, and buffer containing low calcium upon global myocardial ischemic injury

This study was designed to compare the effects of the Ca2+ slow channel blocking agents verapamil (2×10−6 m ), diltiazem (7.5×10−6 m ), nifedipine (7.5×10−7 m ), and buffer containing reduced Ca2+ content (0.95 m m ) on myocardial ischemic injury. These treatments were equiactive, reducing cardiac function to 20% of the control value, and fully reversible in nonischemic, isolated, working rat hearts. Hearts which were reperfused (30 min) following 27 min of global ischemia recovered 17% of control cardiac function and had a markedly reduced ATP and creatine phosphate content and ATP/ADP ratio compared to nonischemic hearts. When verapamil, diltiazem, nifedipine, or low Ca2+ treatments were given before and during ischemia, equal improvement in cardiac function was observed upon reperfusion, and tissue ATP levels, creatine phosphate levels, and ATP/ADP ratio were significantly higher than in hearts which did not receive the treatments or which received the drug vehicle. Large increases in recovery of contractile function were observed with a partial preservation of ATP reserves. These treatments, which were equiactive in nonischemic hearts, provided equivalent presevation of cardiac function, ATP, and creatine phosphate in the reperfused ischemic hearts. When the ischemic period was increased to 33 min and the effective concentrations reduced to depress cardiac function to 40% of the control value (4.5×10−7 m verapamil, 2.5×10−6 m diltiazem, 3×10−7 m Nifedipine, 1.25 m m Ca2+) equal improvement in cardiac function was again observed. Thus, major differences among these Ca2+ slow channel blockers or low Ca2+ treatment were not detected in this experimental system.
A Single Vegetative Actin Isovariant Overexpressed under the Control of Multiple Regulatory Sequences Is Sufficient for Normal Arabidopsis Development

The relative significance of gene regulation and protein isovariant differences remains unexplored for most gene families, particularly those participating in multicellular development. Arabidopsis thaliana encodes three vegetative actins, ACT2, ACT7, and ACT8, in two ancient and highly divergent subclasses. Mutations in any of these differentially expressed actins revealed only mild phenotypes. However, double mutants were extremely dwarfed, with altered cell and organ morphology and an aberrant F-actin cytoskeleton (e.g., act2-1 act7-4 and act8-2 act7-4) or totally root-hairless (e.g., act2-1 act8-2). Our studies suggest that the three vegetative actin genes and protein isovariants play distinct subclass-specific roles during plant morphogenesis. For example, during root development, ACT7 was involved in root growth, epidermal cell specification, cell division, and root architecture, and ACT2 and ACT8 were essential for root hair tip growth. Also, genetic complementation revealed that the ACT2 and ACT8 isovariants, but not ACT7, fully rescued the root hair growth defects of single and double mutants. Moreover, we synthesized fully normal plants overexpressing the ACT8 isovariant from multiple actin regulatory sequences as the only vegetative actin in the act2-1 act7-4 background. In summary, it is evident that differences in vegetative actin gene regulation and the diversity in actin isovariant sequences are essential for normal plant development.
Curve-drawing algorithms for Raster displays

The midpoint method for deriving efficient scan-conversion algorithms to draw geometric curves on raster displays in described. The method is general and is used to transform the nonparametric equation f(x,y) = 0, which describes the curve, into an algorithms that draws the curve. Floating point arithmetic and time-consuming operations such as multiplies are avoided. The maximum error of the digital approximation produced by the algorithm is one-half the distance between two adjacent pixels on the display grid. The midpoint method is compared with the two-point method used by Bresenham, and is seen to be more accurate (in terms of the linear error) in the general case, without increasing the amount of computation required. The use of the midpoint method is illustrated with examples of lines, circles, and ellipses. The considerzations involved in using the method to derive algorithms for drawing more general classes of curves are discussed.
Developing haptic and visual perceptual categories for reaching and grasping with a humanoid robot

Abstract Properties of the human embodiment — sensorimotor apparatus and neurological structure — participate directly in the growth and development of cognitive processes against enormous worst case complexity. It is our position that relationships between morphology and perception over time lead to increasingly comprehensive models that describe the agent’s relationship to the world. We are applying insight derived from neuroscience, neurology, and developmental psychology to the design of advanced robot architectures. To investigate developmental processes, we have begun to approximate the human sensorimotor configuration and to engage sensory and motor subsystems in developmental sequences. Many such sequences have been documented in studies of infant development, so we intend to bootstrap cognitive structures in robots by emulating some of these growth processes that bear an essential resemblance to the human morphology. In this paper, we will show two related examples in which a humanoid robot determines the models and representations that govern its behavior. The first is a model that captures the dynamics of a haptic exploration of an object with a dextrous robot hand that supports skillful grasping. The second example constructs constellations of visual features to predict relative hand/object postures that lead reliably to haptic utility. The result is a first step in a trajectory toward associative visual-haptic categories that bounds the incremental complexity of each stage of development.
Non-catalyzed addition reactions of Cl3SiSiCl3 with 1,2-diketones, 1,2-quinones and with a 1,4-quinone

Abstract The first uncatalyzed reactions of a disilane with 1,2-diketones, 1,2-quinones and with a 1,4-quinone are reported. Thus, Si 2 Cl 6 reacts under mild conditions with such substrates to give bis-trichlorosiloxy addition compounds. The structure of the corresponding addition compound of benzyl, namely, cis -PhC(OSiCl 3 )C(OSiCl 3 )Ph was structured by X-ray diffraction analysis. Evidence for the intermediacy of five-coordinate species in these reactions is discussed. A reaction of Si 2 Cl 6 with LiNMeC(O)Et aimed at making a hypercoordinate silicon complex led to the disproportionation product cis -Cl 2 Si[NMeC(O)Et] 2 (whose structure was also determined by X-ray diffraction analysis) in which the amide ligands chelate the silicon via the nitrogen and oxygen to form five-membered rings whose bond lengths suggest substantial electron delocalization.
Air entrainment in mortars and concrete: The effect of superplasticizer/salt combinations

The use of salt-saturated solutions in mixing super plasticized mortars and concretes will sometimes lead to the entrainment of large quantities of air (in excess of 20 per cent, often as high as 50 per cent). The author describes a test to quantify the potential of various superplasticizers to entrain air when used in salt-containing mortars and concrete. A solid form of a sulphonated naphthalene formaldehyde condensate (SNFC) was mixed with saturated brine solution, with and without defoaming agents, and the level of foaming was measured. The test was repeated using 20 per cent active liquid sulphonated melamine formaldehyde condensate (SMFC) in place of SNFC. In the case of SNFC, reaction with the salt produced a large amount of relatively stable foam, only partially controlled by defoamers. In the case of SMFC there is less foaming and it can be effectively controlled with a defoamer. The test described is a simple one which allows quick determination of the potential for foaming. (TRRL)
Percutaneous Tube Pericardiostomy.

The classic subxiphoid pericardial window technique and the newer, minimally invasive percutaneous fluoroscopy- controlled method of surgical treatment of pericardial effusions and/or tamponade are reviewed and compared based on 12 years of surgical experience. Since 1988, 114 patients underwent surgery for treatment of pericardial effusion and/or tamponade. The classic subxiphoid approach was used on 66 patients, and since 1993, the percutaneous tube pericardiostomy method was employed on 48 patients. In choosing a method for pericardial decompression, disease etiology and patient characteristics must be considered as well as the experience of the surgeon.
Structure of a bacterial photosynthetic membrane: Integrity of reaction centers following proteolysis and detergent solubilization

The photosynthetic membranes of the purple bacterium Rhodopseudomonas viridis are composed of a semi-crystalline lattice of subunits. Proteolysis of isolated membranes with trypsin or pronase results in the degradation of polypeptides associated with the photosynthetic reaction center. However, two low molecular weight peptides which may form the light-harvesting complex survive the enzymatic treatment. The proteolysis does not affect the major absorbance peak (830 nm) associated with the reaction center. However, treatment of proteolyzed membranes with detergents such as LDAO abolishes the 830 nm absorbance peak. The 830 nm peak is stable following LDAO solubilization of non-proteolyzed membranes. These results suggest that a combination of covalent and non-covalent interactions are important in maintaining the configuration of the reaction center, and are consistent with a model of membrane organization in which the light-harvesting components are buried in a lipid phase of the membrane and reaction center components form the large structures which electron microscope studies have shown to extend from either membrane surface.
SCOLICA ENCHIRIADIS AND THE ‘NON-DIATONIC’ PLAINSONG TRADITION

Although medieval plainsong is known as a primarily diatonic repertory, the presence of a ‘non-diatonic’ tradition was brought to light long ago in the work of Jacobsthal, Delalande and others. This essay considers some aspects of this practice that have not been fully examined in previous studies and explores their relationship to early medieval theory and pedagogy. In the solo verses of the offertory chants, large sections are displaced from the diatonic background scale, sometimes permanently. The conception of irregular semitones presented in Scolica enchiriadis yields insight into this extensive ‘non-diatonic’ practice and has implications for interpreting variant readings of these problem spots. The final section of the essay explores some aspects of the Enchiriadis reception that point to changes in tone-system and pitch conception, shedding light on the contexts surrounding the suppression of irregular semitones.
Property Reductive Emergent Dualism

This paper sketches and motivates a metaphysics of mind that is both substance dualist and, to a large extent, property reductive. Call it “property reductive emergent dualism”. Section “Emergent Dualism” gives the broad outlines of the view. Sections “Problems of Mental Causation” and “Theoretical Virtues” argue that it can claim several advantages over non-reductive physicalist theories of mind. Section “Problems of Mental Causation” considers metaphysical challenges to mental causation in detail. Section “Theoretical Virtues” considers overall theoretical virtues: ontological and ideological economy, unification with physical sciences, the promise of explanatory gain. On these grounds, I propose that the view coupling substance dualism with property reductivism deserves further philosophical attention.
Vertebral artery stenting utilizing distal embolic protection with filter wire and a drug-eluting Taxus stent.

Percutaneous intervention of the vertebral artery stenosis is associated with the risk of distal embolization and restenosis, which can manifest with stroke. We describe a case of vertebral artery percutaneous intervention utilizing the embolic protection FilterWire and a drug‐eluting Taxus stent, to overcome these issues of distal embolization and restenosis respectively.
The interaction of semantic memory with storage and retrieval processes.

A procedure for separating storage from retrieval (R. Chechile & D. L. Meyer, Journal of Mathematical Psychology, 1976, 14, 430–437) lead to the conclusion that memory development involves changes in both storage and retrieval. Nevertheless, these changes resulted from the interaction of storage and retrieval mechanisms with the age-related elaboration of the semantic memory system. This study shows that the memory improvement with age, between kindergarten and second grade, vanished when the meaningfulness of the materials were equated. The most plausible interpretation of the results is the hardware invariance hypothesis. According to that hypothesis, the memory apparatus for information processing is constant across ages, but the hardware is used more effectively if there is a better-developed semantic memory system.
Copepods of the Family Taeniacanthidae Parasitic On South Indian Fishes

[J'ai donne dans cet article la description de huit especes dont trois appartiennent au genre Taeniacanthus, deux a Parataeniacanthus, une a Irodes, une autre a Anchistrotos, et la derniere a Metataeniacanthus nov. Toutes ces especes, a une exception pres, sont de nouvelles especes et l'une appartient a un nouveau genre. On trouvera aussi ici une discussion sur l'imperfection de la definition des genres groupes dans la famille des Taeniacanthidae., J'ai donne dans cet article la description de huit especes dont trois appartiennent au genre Taeniacanthus, deux a Parataeniacanthus, une a Irodes, une autre a Anchistrotos, et la derniere a Metataeniacanthus nov. Toutes ces especes, a une exception pres, sont de nouvelles especes et l'une appartient a un nouveau genre. On trouvera aussi ici une discussion sur l'imperfection de la definition des genres groupes dans la famille des Taeniacanthidae.]
Comparison of DNA facilitators in the uptake and intracellular fate of infectious herpes simplex virus type 2 DNA

The comparative efficiencies of polyornithine, CaCl2 and DEAE-dextran in enhancing the infectivity of exogenous herpes simplex virus (HSV) type 2 DNA were examined. CaCl2 was 12-times more effective in promoting genetic expression of viral DNA than DEAE-dextran, while polyornithine did not mediate any HSV DNA infectivity. A comparison of sedimentation profiles of DNA extracted from cells inoculated with viral DNA in the presence of each facilitator revealed that input 56 S HSV DNA underwent marked alteration with time. There was also extensive processing of a 20 S DNA species. The data indicated that the biological efficiency of each facilitator was related to the amount of 20 S DNA remaining at the final time periods. One possible explanation for the efficiency of CaCl2 as a facilitator was that it allowed for the reutilization of the 20 S DNA species during HSV replication. The persistence of the 20 S peak in cells treated with DEAE-dextran was a measure of the decreased efficacy of this facilitator. Finally, the absence of a 56 S peak and the greatly elevated levels of 20 S DNA at final time points in polyornithine-treated cells accounted for the failure of this compound to promote HSV DNA infectivity.
Synthesis and in vitro and in vivo evaluation of 18F-labeled positron emission tomography (PET) ligands for imaging the vesicular acetylcholine transporter.

A new class of vesicular acetylcholine transporter inhibitor that incorporates a carbonyl group into the benzovesamicol structure was synthesized, and analogues were evaluated in vitro. (±)-trans-2-Hydroxy-3-(4-(4-[18F]fluorobenzoyl)piperidino)tetralin (9e) has Ki values of 2.70 nM for VAChT, 191 nM for σ1, and 251 nM for σ2. The racemic precursor (9d) was resolved via chiral HPLC, and (±)-[18F]9e, (−)-[18F]9e, and (+)-[18F]9e were respectively radiolabeled via microwave irradiation of the appropriate precursors with [18F]/F− and Kryptofix/K2CO3 in DMSO with radiochemical yields of ∼50−60% and specific activities of >2000 mCi/μmol. (−)-[18F]9e uptake in rat brain was consistent with in vivo selectivity for the VAChT with an initial uptake of 0.911 %ID/g in rat striatum and a striatum/cerebellum ratio of 1.88 at 30 min postinjection (p.i.). MicroPET imaging of macaques demonstrated a 2.1 ratio of (−)-[18F]9e in putamen versus cerebellum at 2 h p.i. (−)-[18F]9e has potential to be a PET tracer for clinical ...
Acquisition of Speech by Children Who Have Prolonged Cochlear Implant Experience

The four purposes of this investigation were to assess whether children acquire intelligible speech following prolonged cochlear-implant experience and examine their speech error patterns, to exami...
Intrinsic Amino Acid Side-Chain Hydrophilicity/Hydrophobicity Coefficients Determined by Reversed-Phase High-Performance Liquid Chromatography of Model Peptides: Comparison with Other Hydrophilicity/Hydrophobicity Scales

An accurate determination of the intrinsic hydrophilicity/hydrophobicity of amino acid side-chains in peptides and proteins is fundamental in understanding many area of research, including protein folding and stability, peptide and protein function, protein-protein interactions and peptide/protein oligomerization, as well as the design of protocols for purification and characterization of peptides and proteins. Our definition of intrinsic hydrophilicity/hydrophobicity of side-chains is the maximum possible hydrophilicity/hydrophobicity of side-chains in the absence of any nearest-neighbor effects and/or any conformational effects of the polypeptide chain that prevent full expression of side-chain hydrophilicity/hydrophobicity. In this review, we have compared an experimentally derived intrinsic side-chain hydrophilicity/hydrophobicity scale generated from RP-HPLC retention behavior of de novo designed synthetic model peptides at pH 2 and pH 7 with other RP-HPLC-derived scales, as well as scales generated from classic experimental and calculation-based methods of octanol/water partitioning of Nalpha-acetyl-amino-acid amides or free energy of transfer of free amino acids. Generally poor correlation was found with previous RP-HPLC-derived scales, likely due to the random nature of the peptide mixtures in terms of varying peptide size, conformation and frequency of particular amino acids. In addition, generally poor correlation with the classical approaches served to underline the importance of the presence of a polypeptide backbone when generating intrinsic values. We have shown that the intrinsic scale determined here is in full agreement with the structural characteristics of amino acid side-chains.
Effect of inhibitors of protein synthesis on rat liver spermidine N1-acetyltransferase

Abstract The increase in spermidine N1-acetyltransferase activity in rat liver produced by carbon tetrachloride was completely prevented by simultaneous treatment with inhibitors of protein and nucleic acid synthesis suggesting that the increase results from the synthesis of new protein rather than the release of the enzyme from a cryptic inactive form. Treatment with cycloheximide 2 h after carbon tetrachloride also completely blocked the rise in spermidine N1-acetyltransferase seen 4 h later. Such treatment completely prevented the fall in spermidine and rise in putrescine in the liver 6 h after carbon tetrachloride confirming the importance of the induction of spermidine N1-acetyltransferase in the conversion of spermidine into putrescine. When cycloheximide was administered to rats in which spermidine N1-acetyltransferase activity had been stimulated by prior treatment with carbon tetrachloride or thioacetamide, the activity was lost rapidly showing that the enzyme protein has a rapid rate of turnover. The half-life for the enzyme in thioacetamide-treated rats was 40 min, whereas the half-life for ornithine decarboxylase (which is well known to turn over very rapidly) was 27 min. In carbon tetrachloride-treated rats the rate of protein degradation was reduced and the half-life of spermidine N1-acetyltransferase was 155 min and that for ornithine decarboxylase was 65 min. It appears that three of the enzymes involved in the synthesis and interconversion of putrescine and spermidine namely, ornithine decarboxylase, S-adenosylmethionine decarboxylase and spermidine N1-acetyltransferase have rapid rates of turnover and that polyamine levels are regulated by changes in the amount of these enzymes.
Interaction of adsorbates with electric-field fluctuations near surfaces: Nonradiative lifetimes and energy-level shifts

In the vacuum above surfaces, there are zero-point fluctuations in the electromagnetic field generated by zero-point charge fluctuations in the substrate. A molecule near the surface will couple to such fluctuations, with the consequence that excited states may decay via nonradiative transitions in which energy is transferred to the electronic excitations of the substrate (surface plasmons, particle hole pairs). In addition, coupling to the fluctuations will produce energy-level shifts not included in the standard version of density-functional theory. We develop a formalism that allows one to calculate the nonradiative lifetimes from this interaction, and also the energy-level shifts. We treat the electric-field fluctuations within the framework of a phenomenological theory that relates their amplitude and frequency spectrum to the optical dielectric constants of the materials from which the substrate complex is fabricated. We demonstrate that when the formalism is applied to a structureless, highly localized electron, the energy-level shift is just that given by the image potential of classical dielectric theory. In real systems one must include the effect of virtual transitions to excited states in the analysis of the level shifts. We present a quantitative study of the nonradiative lifetime of the lowest unoccupied molecular orbital $(\mathrm{LUMO})+1$ state of the magnesium porphine molecule, adsorbed on the oxide covered NiAl(110) surface, along with calculations of the energy-level shifts induced by the field fluctuations for this system. Our calculated nonradiative lifetime is in good accord with experimental data.
Distribution of ionospheric currents induced by the solar wind interaction with Venus

Abstract The electric currents induced in the atmosphere of a non-magnetic planet such as Venus by the interaction of the solar wind satisfy a generalized Ohm's Law relationship with tensor conductivity. The distribution of these currents within the planetary ionosphere may be calculated by a variational technique which minimizes the Joule heating over the ionospheric volume. In this paper, we present the development of the variational technique, and apply it to a model of the solar wind interaction with Venus. Potential and current distributions are shown, and the use of these distributions in determining convective transport patterns of planetary ions is discussed.
Philosophy of (Lived) Religion

The cohabitation of philosophy with the study of religion has such a long history that we have not been motivated to consider the terms of that relationship. This paper proposes that this relationship needs to be examined radically. That is to say it proposes to query the nature, or possible natures, of the relationship of philosophy to the study of religion by posing such questions as the following: What kind of philosophy belongs in the study of religion? Constructive? Critical? Does philosophy have an independent role in the study of religion or does it, rather, best play the role of ‘handmaiden’? To the extent that philosophy plays an integral part in the study of religion, how should philosophy reflect the global and cross-cultural nature of the study of religion? To what extent does a philosophy that is integral to the study of religion need to change in order to reflect the philosophical agendas integral to other religions than Christianity? La cohabitation de la philosophie avec l’etude de la reli...
Point mutations in the guanine phosphoribosyltransferase from Giardia lamblia modulate pyrophosphate binding and enzyme catalysis.

Guanine phosphoribosyltransferase (GPRTase) from Giardia lamblia, an enzyme required for guanine salvage and necessary for the survival of this parasitic protozoan, has been kinetically characterized. Phosphoribosyltransfer proceeds through an ordered sequential mechanism common to many related purine phosphoribosyltransferases (PRTases) with α-D-5-phosphoribosyl-1-pyrophosphate (PRPP) binding to the enzyme first and guanosine monophosphate (GMP) dissociating last. The enzyme is a highly unique purine PRTase, recognizing only guanine as its purine substrate (Km = 16.4 µm) but not hypoxanthine (Km > 200 µm) nor xanthine (no reaction). It also catalyzes both the forward (kcat = 76.7 s−1) and reverse (kcat = 5.8·s−1) reactions at significantly higher rates than all the other purine PRTases described to date. However, the relative catalytic efficiencies favor the forward reaction, which can be attributed to an unusually high Km for pyrophosphate (PPi) (323.9 µm) in the reverse reaction, comparable only with the high Km for PPi (165.5 µm) in Tritrichomonasfoetus HGXPRTase-catalyzed reverse reaction. As the latter case was due to the substitution of threonine for a highly conserved lysine residue in the PPi-binding loop [Munagala et al. (1998) Biochemistry37, 4045–4051], we identified a corresponding threonine residue in G. lamblia GPRTase at position 70 by sequence alignment, and then generated a T70K mutant of the enzyme. The mutant displays a 6.7-fold lower Km for PPi with a twofold increase in the Km for PRPP. Further attempts to improve PPi binding led to the construction of a T70K/A72G double mutant, which displays an even lower Km of 7.9 µm for PPi. However, mutations of the nearby Gly71 to Glu, Arg, or Ala completely inactivate the GPRTase, suggesting the requirement of flexibility in the putative PPi-binding loop for enzyme catalysis, which is apparently maintained by the glycine residue. We have thus tentatively identified the PPi-binding loop in G. lamblia GPRTase, and attributed the relatively higher catalytic efficiency in the forward reaction to the unusual loop structure for poor PPi binding in the reverse reaction.
Beryllium doping and silicon amphotericity in (1 1 0) GaAs-based heterostructures: structural and optical properties

Abstract The use of beryllium as an acceptor at high doping levels in (1 1 0)GaAs-based heterostructures is found to be deleterious to the structural and optical properties of these epi-layers. This may limit the use of beryllium as a p-type dopant on the (1 1 0) surface. Because silicon is amphoteric on the (1 1 0), it can be used as an alternative p-type dopant, in addition to its traditional role as an n-type dopant. Transmission electron microscopy, optical absorption, and luminescence data indicate that high quality multiple quantum well structures with p-type GaAs buffer layers doped with silicon, rather than beryllium, can be grown.
The biosynthesis of isoprenoid lipids including ubiquinone in muscle from normal and genetically dystrophic mice.

Abstract The concentration and rates of biosynthesis of ubiquinone, squalene, and cholesterol were studied in muscle from genetically dystrophic mice and their heterozygous normal littermates. The biosynthesis of ubiquinone from its 14 C-benzoic acid precursor was studied in vivo , and from its isoprenoid sidechain precursor 2- 14 C-MVA lactone, in vitro . The ubiquinone and cholesterol content per gram of dystrophic skeletal muscle was increased above normal 80–100%, whereas squalene concentration was unchanged. The rate of biosynthesis of ubiquinone was increased in dystrophic muscle by a factor of 1.5–3.4 over controls. The mitochondrial content of ubiquinone in normal and dystrophic muscle was the same, but extramitochondrial ubiquinone was increased in the dystrophic mouse. Succinic dehydrogenase activities were also unchanged in mitochondria from dystrophic muscle. These data do not support the view that a deficiency of ubiquinone exists in the dystrophic muscle. In fact, the excess in synthesis of ubiquinone and squalene indicate a disturbance in the regulation of the biosynthesis of isoprenoid compounds in muscle which may be intrinsic to the genetic disorder of muscular dystrophy.
Plasma protein thiol oxidation and carbonyl formation in chronic renal failure

Plasma protein thiol oxidation and carbonyl formation in chronic renal failure. Background Myeloperoxidase-catalyzed oxidative pathways have recently been identified as an important cause of oxidant stress in uremia and hemodialysis (HD), and can lead to plasma protein oxidation. We have examined patterns of plasma protein oxidation in vitro in response to hydrogen peroxide (H 2 O 2 ) and hypochlorous acid (HOCl). We measured thiol oxidation, amine oxidation, and carbonyl concentrations in patients on chronic maintenance HD compared with patients with chronic renal failure (CRF) and normal volunteers. We have also examined the effect of the dialysis procedure on plasma protein oxidation using biocompatible and bioincompatible membranes. Methods Plasma proteins were assayed for the level of free thiol groups using spectrophotometry, protein-associated carbonyl groups by enzyme-linked immunosorbent assay, and oxidation of free amine groups using a fluorescent spectrophotometer. Results In vitro experiments demonstrate HOCl oxidation of thiol groups and increased carbonyl formation. In vivo, there are significant differences in plasma-free thiol groups between normal volunteers (279 ± 12 μmol/L), CRF patients (202 ± 20 μmol/L, P = 0.005) and HD patients (178 ± 18 μmol/L, P = 0.0001). There are also significant differences in plasma protein carbonyl groups between normal volunteers (0.76 ± 0.51 μmol/L), CRF patients (13.73 ± 4.45 μmol/L, P = 0.015), and HD patients (16.95 ± 2.62 μmol/L, P = 0.0001). There are no significant differences in amine group oxidation. HD with both biocompatible and bioincompatible membranes restored plasma protein thiol groups to normal levels, while minimally affecting plasma protein carbonyl expression. Conclusions First, both CRF and HD patients have increased plasma protein oxidation manifested by oxidation of thiol groups and formation of carbonyl groups. Second, HD with biocompatible and bioincompatible membranes restored plasma protein thiol groups to normal levels. Third, these experiments suggest that there is a dialyzable low molecular weight toxin found in uremia that is responsible for plasma protein oxidation.
Sex differences in arterial stiffness and ventricular-arterial interactions.

Objectives This study sought to assess sex differences in ventricular-arterial interactions. Background Heart failure with preserved ejection fraction is more prevalent in women than in men, but the basis for this difference remains unclear. Methods Echocardiography and arterial tonometry were performed to quantify arterial and ventricular stiffening and interaction in 461 participants without heart failure (189 men, age 67 ± 9 years; 272 women, age 65 ± 10 years). Aortic characteristic impedance (Z c ), total arterial compliance (pulsatile load), and systemic vascular resistance index (steady load) were compared between men and women, and sex-specific multivariable regression analyses were performed to assess associations of these arterial parameters with diastolic dysfunction and ventricular-arterial coupling (effective arterial elastance/left ventricular end-systolic elastance [Ea/Ees]) after adjustment for potential confounders. Results Z c was higher and total arterial compliance was lower in women, whereas systemic vascular resistance index was similar between sexes. In women but not men, higher log Z c was associated with mitral inflow E/A ratio (β ± SE: −0.17 ± 0.07), diastolic dysfunction (odds ratio: 7.8; 95% confidence interval: 2.0 to 30.2) and Ea/Ees (β ± SE: 0.13 ± 0.04) (p ≤ 0.01 for all). Similarly, total arterial compliance was associated with E/A ratio (β ± SE: 0.12 ± 0.04), diastolic dysfunction (odds ratio: 0.33; 95% confidence interval: 0.12 to 0.89), and Ea/Ees (β ± SE: −0.09 ± 0.03) in women only (p ≤ 0.03 for all). Systemic vascular resistance index was not associated with diastolic dysfunction or Ea/Ees. Conclusions Proximal aortic stiffness (Z c ) is greater in women than men, and women may be more susceptible to the deleterious effects of greater pulsatile and early arterial load on diastolic function and ventricular-arterial interaction. This may contribute to the greater risk of heart failure with preserved ejection fraction in women.
Influence of agricultural practices on nitrates in the water table aquifer

Abstract Water samples for nitrate testing were collected from over 200 wells in Kent and Sussex counties in Delaware over an 18-month period in areas with different agricultural land use. Nearly 70% of the wells were individual home water supplies. The rest of the wells, constructed from 3·2-cm diameter PVC pipe, were installed at selected locations. Water samples were also collected from monitoring wells around two potato-growing sites, on irrigated corn and soybean areas, a field spread with poultry manure, two animal-waste lagoon sites, and near stockpiled poultry manure. Certain agricultural activities cause higher nitrate concentrations in the ground water. Poultry manure has increased nitrate concentrations in the ground water in southern Delaware more than commercial fertilizer. Highest nitrate concentrations are found in areas with excessively well-drained soils. Some clay-lined, animal-waste lagoons may cause ground-water contamination. Potato growing in Delaware is not causing high nitrate concentrations in the water table aquifer because of the heavier soils that are not as susceptible to nitrite leaching.
Rhodanese-iron protein association in bovine liver extracts

Abstract In semi-crude liver extracts, rhodanese is associated with iron protein. A component purified from mitochondrial extracts exhibits the properties of a rhodanese-apoprotein complex. It can be converted to a rhodanese-iron protein complex by incubation with iron ions, mercaptoethanol, and the sulfur-donor substrate, thiosulfate ion. The protein complex evidences an extinction coefficient close to 5000 per mole of bound iron near 400 nm. Estimates of labile sulfide for these preparations range from 0.6–0.9 mole per mole of bound iron. Furthermore, in the rhodanese-catalyzed thiosulfate-cyanide reaction, iron ion is an inhibitor competitive with cyanide suggesting that iron ion serves as a physiological sulfur-acceptor substrate for the enzyme.
Two-rate method for simultaneous determination of l-amino acid mixtures

Abstract A new kinetic-based method for simultaneous determination of binary mixtures is proposed that is simple, rapid, and minimizes errors arising from drift. This new method is based on the measurement of the rate at two points during the course of the enzymatic reaction and is therefore referred to as a two-rate method. The performance of the method is evaluated by the l -amino acid oxidase/Trinder reaction for the determination of binary mixtures of l -amino acids under the same conditions using air-segmented continuous flow/stopped-flow methodology. Some assumptions with this method are presented and supported by experimental data.
Simple relations between principal stratification and direct and indirect effects

The concepts of principal strata direct and indirect effects are compared with and contrasted to definitions of direct and indirect effects which make reference to interventions on intermediate variables. Certain simple relations hold for direct effects but not indirect effects.
Role of Fas–FasL interactions in the pathogenesis and regulation of autoimmune demyelinating disease

Abstract Multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE) represent complex processes that lead to destruction of oligodendrocytes (ODCs) and myelin. T cells are integral to the development of these diseases, but whether T cell-mediated cytolytic mechanisms are involved in the destruction of MHC Class II-negative targets, such as oligodendroglia and myelin, in the CNS is unclear. The primary lytic mechanism employed by CD4 + T cells is Fas-dependent, but can be MHC- un restricted. Thus, T cell-mediated Fas–FasL interactions could directly contribute to the pathology of EAE and MS. This review summarizes studies from our laboratory and others that implicate Fas–FasL interactions in both the pathogenesis and regulation of demyelinating diseases.