cssi/SciSciGPT-SciSciNet huggingface dataset:
Inhibition of Gamma-Secretase Activity Promotes Differentiation of Embryonic Pancreatic Precursor Cells into Functional Islet-like Clusters in Poly(Ethylene Glycol) Hydrogel Culture

We assessed the ability of a gamma-secretase inhibitor to promote the in vitro differentiation of induced embryonic pancreatic precursor cell aggregates into functional islet-like clusters when encapsulated within a three-dimensional hydrogel. Undifferentiated pancreatic precursor cells were isolated from E.15 rat embryos, dissociated into single cells, and aggregated in suspension-rotation culture. Aggregates were photoencapsulated into poly(ethylene glycol) hydrogels with entrapped collagen type 1 and cultured for 14 days with or without a gamma-secretase inhibitor. Gene expression, proinsulin content, and C-peptide release were measured to determine differentiation and maturation of encapsulated precursor cell aggregates. In the control medium, scattered breakthrough beta cell differentiation was observed; however, cells remained largely insulin negative. Upon addition of a gamma-secretase inhibitor the majority of cells in clusters became insulin positive, and insulin per DNA and glucose-stimulated in...
The Center for Reservoir Research over Its First Twenty Years with Special Reference to the Long-term Monitoring Program

ABSTRACT The Center for Reservoir Research (CRR) at Murray State University is nearing its 20th year. A series of papers on CRR research and education were presented at the 2006 meeting of the Ohio River Basin Consortium for Research and Education, and a selection of these is included in this issue of the Journal of the Kentucky Academy of Science. A major component of CRR is the Long-term Monitoring Program on Kentucky Lake and the resulting database. The database contains suites of physicochemical and biological data that have been collected primarily on 16 or 32 day cycles since 1988. These data are available to students and scientists through the CRR website.
The direct determination of the ionization potentials of CH and CH3 using the electron propagator method with a multiconfigurational second-order perturbation theory wavefunction as the initial state (EPCASPT2)

Abstract We directly determine the first two vertical ionization potentials (IPs) of two small organic radicals, CH and CH3, using a new method, the electron propagator method with a multiconfigurational second-order perturbation theory wavefunction (EPCASPT2) and using the multiconfigurational spin tensor electron propagator method (MCSTEP). Our IPs using EPCASPT2 are in excellent agreement compared to full configuration interaction (ΔFCI). For CH MCSTEP and EPCASPT2 give very accurate IPs to the lowest two cation states. For CH3, the lowest MCSTEP IP is inaccurate while the EPCASPT2 IPs effectively mimics ΔFCI IPs for all the IPs determined.
Reducing transmission investment to meet Renewable Portfolio Standards Using Smart Wires

Increasing societal concern for global warming and energy security have led many of the US states to adopt policies like Renewable Portfolio Standards (RPS). Introduction of these environmental policies in the energy market are expected to have significant impact on grid operation as well transmission investment. The energy delivery system has to be upgraded significantly in order to make it capable of handling these changes. It has been claimed that upgrading the present transmission system to a Smart Grid would facilitate the integration of renewable resources. Smart Wires are distributed, low cost, autonomous smart assets that are capable of controlling power flow in a meshed transmission network. This paper studies the benefit of Smart Grid technologies like Smart Wires in reducing transmission investment that is required to implement policies like the RPS.
Charge delocalization and structural response in layered La 1.2 Sr 1.8 Mn 2 O 7 : Enhanced distortion in the metallic regime

Temperature-dependent neutron diffraction studies on melt-grown crystals of the layered compound La{sub 1.2}Sr{sub 1.8}Mn{sub 2}O{sub 7} reveal a dramatic structural response to the onset of ferromagnetism and the coincident insulator-metal transition. Unlike the related manganite perovskites, whose Jahn-Teller distorted octahedra become more regular at temperatures below the insulator-metal transition, the MnO{sub 6} octahedra of this layered material are more severely distorted when the charge is itinerant than when it is localized. {copyright} {ital 1997} {ital The American Physical Society}
Post therapy imaging in high dose I‐131 radioimmunotherapy patients

The biodistribution of a trace-labeled I-131 antibody is used to predict the biodistribution of a high dose I-131 antibody for therapy. Internal radiation dose estimates derived from the trace-labeled antibody have been used to determine the I-131 doses in a phase I escalating dose therapy trial for hematologic malignancy. To confirm the hypothesis that the distribution of a trace- and high-dose labeled antibodies are similar, both trace (7-11 mCi, 259-407 MBq) and high-dose (100-800 mCi, 3700-29600 MBq) I-131 radiolabeled antibody infusion were imaged in 12 patients who were treated for leukemia or lymphoma. With specialized imaging techniques using lead attenuation sheets, clearance data from organs were obtained from serial gamma camera images. Biological clearance half times of I-131 from both trace and therapy level doses were in agreement. An exception was a patient who developed human antimouse antibody before therapy, and subsequently had rapid clearance of the therapy dose. The method was feasible, yielded reproducible results, and provided critical data for relating therapy toxicity to radiation absorbed dose estimates.
Chronic stress, metabolism, and metabolic syndrome

The prevalence of obesity has rapidly escalated and now represents a major public health concern. Although genetic associations with obesity and related metabolic disorders such as diabetes and cardiovascular disease have been identified, together they account for a small proportion of the incidence of disease. Environmental influences such as chronic stress, behavioral and metabolic disturbances, dietary deficiency, and infection have now emerged as contributors to the development of metabolic disease. Although epidemiological data suggest strong associations between chronic stress exposure and metabolic disease, the etiological mechanisms responsible remain unclear. Mechanistic studies of the influence of chronic social stress are now being conducted in both rodent and nonhuman primate models, and phenotypic results are consistent with those in humans. The advantage of these models is that potential neural mechanisms may be examined and interventions to treat or prevent disease may be developed and tested. Further, circadian disruption and metabolic conditions such as diabetes mellitus could increase susceptibility to other stressors or serve as a stressor itself. Here, we review data from leading investigators discussing the interrelationship between chronic stress and development of metabolic disorders.
Proportional heading control for planar navigation: The Chaplygin beanie and fishlike robotic swimming

We present a simple method for the coupled propulsion and steering of certain single-input planar vehicles. We demonstrate the applicability of this method to two distinct systems, one a hybridization of canonical systems from the mechanics literature and the other a fishlike robot. The first system is examined analytically, the second experimentally.
Neuroprotective concentrations of the N-methyl-D-aspartate open-channel blocker memantine are effective without cytoplasmic vacuolation following post-ischemic administration and do not block maze learning or long-term potentiation.

Abstract The potential of most N-methyl- D -aspartate antagonists as neuroprotectants is limited by side effects. We previously reported that memantine is an open-channel N-methyl- D -aspartate blocker with a faster off-rate than many uncompetitive N-methyl- D -aspartate antagonists such as dizocilpine maleate. This parameter correlated with memantine's known clinical tolerability in humans with Parkinson's disease. Memantine is the only N-methyl- D -aspartate antagonist that has been used clinically for excitotoxic disorders at neuroprotective doses. Therefore, we wanted to investigate further the basis of its clinical efficacy, safety, and tolerability. Here we show for the first time for any clinically-tolerated N-methyl- D -aspartate antagonist that memantine significantly reduces infarct size when administered up to 2 h after induction of hypoxia/ischemia in immature and adult rats. We found that at neuroprotective concentrations memantine results in few adverse side effects. Compared to dizocilpine maleate, memantine displayed virtually no effects on Morris water maze performance or on neuronal vacuolization. At concentrations similar to those in brain following clinical administration, memantine (6–10 μM) did not attenuate long-term potentiation in hippocampal slices and substantially spared the N-methyl- D -aspartate component of excitatory postsynaptic currents, while dizocilpine maleate (6–10 μM) or D-APV (50 μM) completely blocked these phenomena. We suggest that the favorable kinetics of memantine interaction with N-methyl- D -aspartate channels may be partly responsible for its high index of therapeutic safety, and make memantine a candidate drug for use in many N-methyl- D -aspartate receptor-mediated human CNS disorders.
Characterizations of the values of differential games

The upper and lower directional derivates of the value function of a differential game are shown to satisfy certain relationships. These relationships imply that the value is a viscosity solution of the Isaacs equation.
Benefits of IEC 61850 standard for power monitoring and management systems in forest products industries

The IEC 61850 standard, using Ethernet as its primary communication architecture, can be utilized in a fashion to significantly benefit pulp and paper process users. While IEC 61850 defines three types of communication: Generic Object Oriented Substation Event (GOOSE), Manufacturing Message Specification (MMS), and Sampled Measured Values (SMV), this paper will focus on the benefits of Manufacturing Message Specification (MMS) communications. Utilizing the IEC 61850 communications, measurands can be gathered into a central system. This repository of data can be accessed by multiple users anywhere on the factory or enterprise networks. This data can be used for energy management, load shedding, and complete power system monitoring and control. Additionally, IEC 61850 allows for the command and control, or actuation of protection equipment in the system; therefore reducing start time between failures while also increasing safety levels as remote actuation does not require local access and the use of Personal Protection Equipment (PPE). In modern Supervisory Control and Data Acquisition (SCADA) systems, the measurands and targets are visually displayed providing a visual representation of the electrical and process control system performance. This paper will discuss the merits of constructing an IEC 61850 based monitoring and management solution for forest products and pulp and paper process industries.
Mechanism of synergistic activation of Arp2/3 complex by cortactin and N-WASP

Nucleation promoting factors (NPFs) initiate branched actin network assembly by activating Arp2/3 complex, a branched actin filament nucleator. Cellular actin networks contain multiple NPFs, but how they coordinately regulate Arp2/3 complex is unclear. Cortactin is an NPF that activates Arp2/3 complex weakly on its own, but with WASP/N-WASP, another class of NPFs, potently activates. We dissect the mechanism of synergy and propose a model in which cortactin displaces N-WASP from nascent branches as a prerequisite for nucleation. Single-molecule imaging revealed that unlike WASP/N-WASP, cortactin remains bound to junctions during nucleation, and specifically targets junctions with a ∼160-fold increased on rate over filament sides. N-WASP must be dimerized for potent synergy, and targeted mutations indicate release of dimeric N-WASP from nascent branches limits nucleation. Mathematical modeling shows cortactin-mediated displacement but not N-WASP recycling or filament recruitment models can explain synergy. Our results provide a molecular basis for coordinate Arp2/3 complex regulation. DOI:http://dx.doi.org/10.7554/eLife.00884.001.
SEX DIFFERENCES IN RENAL TOXICITY OF MERCURY IN THE RAT.

A PRONOUNCED sex difference was found to exist in the renal tubules of rats injected intravenously with minimally toxic doses of bichloride of mercury. Mercury, in toxic doses, produces an acute tubular necrosis in a wide variety of experimental animals and man1,2. Histologically, when minimally toxic doses are given to rats, the lesions are confined to the straight portions of the proximal tubules.
High performance GaSb/InAs superlattice long-wave infrared focal plane array

We describe the demonstration of a ¼ VGA format long-wavelength infrared focal plane array based on an InAs/GaSb superlattice absorber surrounded by an electron-blocking and a hole-blocking unipolar barrier. An 8.8 µm cutoff focal plane without antireflection coating based on this complementary barrier infrared detector design has yielded noise equivalent differential temperature of 18.6 mK at operating temperature of 80K, with 300 K background and f/2 cold-stop.
Conzelmann on Luke

HAT this English translation should have appeared at the same time as the third revised edition in German is highly unfortunate. It prompts an open question to English-language publishers: Why is it that readers of such works as this -and this applies above all to students-should be forced to trail behind in scholarly discussion because of tardy and hence dated translations? Even if we make generous allowance for a time differential, why is there such strong resistance to revised editions? In the case of Conzelmann's work, it is indeed good fortune for us to have it in English, but there seems to be no good reason why the publisher should have settled for a version that was dated the day it came off the press. (The history of English-language publishing in theology is full of comparable cases, but one thinks immediately today of the unfortunate situation created in connection with James M. Robinson's A New Quest of the Historical Jesus which has already appeared in German in a revised form.) This unhappy state of affairs explains why references to Conzelmann in what follows here often have to be to the new German edition; in such cases, the references are placed in brackets ( []).1 As Conzelmann indicates, Form-criticism arose in part out of the destruction of the chronological and topographical framework of the life of Jesus, and then concerned itself with the form and content of the tradition-
Dissolution kinetics of calcite at 50–70 °C: An atomic force microscopic study under near-equilibrium conditions

Abstract Direct measurements of calcite ( 10 1 ¯ 4 ) faces were performed using in situ atomic force microscopy (AFM) to reveal the dissolution processes as a function of solution saturation state and temperature. Time-sequential AFM images demonstrated that step velocities at constant temperature increased with increasing undersaturation. The anisotropy of obtuse and acute step velocities appeared to become more significant as solutions approached equilibrium and temperature increased. At saturation state Ω > 0.02, a curvilinear boundary was formed at the intersection of two acute steps and the initially rhombohedral etch pit exhibited a nearly triangular shape. This suggests that the [ 4 ¯ 41 ] a and [ 48 1 ¯ ] a steps may not belong to the calcite-aqueous solution equilibrium system. Further increase in the saturation state (Ω ⩾ 0.3) led to a lack of etch pit formation and dissolution primarily occurred at existing steps, in accordance with Teng (2004) . Analysis of step kinetics at different temperatures yielded activation energies of 25 ± 6 kJ/mol and 14 ± 13 kJ/mol for obtuse and acute steps, respectively. The inconsistencies in etch pit morphology, step anisotropy, and step activation energies from the present study with those of studies far-from-equilibrium can be explained by increased influence of the backward reaction, or growth, near-equilibrium. We propose that the backward reaction occurs preferentially at the acute–acute kink sites. The kinetics and effective activation energies of near-equilibrium calcite dissolution presented in this work provide accurate experimental data under likely CO2 sequestration conditions, and thus are crucial to the development of robust geochemical models that predict the long-term performance of mineral-trapped CO2.
A managed care curriculum developing a managed care curriculum for primary care residents

Introduction Managed care in its numerous forms is continuing to change the face of the healthcare system in the United States. Impact of managed care on medical education As managed care continues to invade the market, it has a substantial influence in shaping the parameters of graduate medical education. Various surveys have shown that residents are under-trained in managed care principles and practice. There is a clear need for a residency curriculum that fully prepares students to keep pace with modern markets. Educational methodology This manuscript describes a curriculum which emphasizes the role of the primary care physician, cost-effective practice, multidisciplinary practice and evidenced-based strategies. Educational methods and concepts presented here are based on the recommendations of healthcare educators, extensive literature searches and United States advisory panels. After the curriculum is completed, the resident will: 1 Practice cost-effectively under 100% capitation and learn proper risk management. 2 Utilize epidemiological thinking and community-oriented primary care. 3 Function as a part of healthcare team and understand how to achieve cost-effective care for patients. 4 Practice the principles of continuous quality improvement and assess patient satisfaction. 5 Practice and adopt evidence-based medicine and guidelines. 6 Become skilled with computers including facility with literature searches, databases and the internet. 7 Practice a full spectrum of primary care emphasizing patient education and psychosocial health. 8 Understand the ethical issues pertinent to managed care practices. Evaluation The residency curriculum committee will evaluate the managed care curricular elements on an on-going basis. Conclusion This comprehensive curriculum for primary care residents can help ensure success in the new healthcare marketplace.
Stimulation of liver detoxication enzymes by dietary cadmium acetate.

Cadmium compounds and other heavy metals usually inhibit enzymic and metabolic processes (Webb 1966). The inhibition of detoxication activity of liver microsomal enzymes would be particularly detrimental to an organism, because the toxicity of many other substances would be increased. In fact, it has recently been reported (Hadley and Miya 1972) that hexobarbital sleep time was prolonged after injection of rats with cadmium acetate. In contrast, the present report contains observations on stimulation of liver microsomal enzyme activity in rats fed cadmium acetate (CdAc) and the interaction of effects of CdAc with those of phenobarbital sodium (PB).
Thick-Restart Lanczos Method for Electronic Structure Calculations

This paper describes two recent innovations related to the restarted Lanczos method for eigenvalue problems, namely the thick-restart technique and dynamic restarting schemes. Previous restarted versions of the Lanczos method use considerably more iterations than the non-restarted versions, largely because too much information is discarded during restarting. The thick-restart technique provides a mechanism to preserve a large portion of the existing basis and dynamic restarting schemes decide exactly how many vectors to save. Combining these two new techniques we are able to implement an efficient eigenvalue problem solver. This paper will demonstrate its effectiveness on one particular class of problems for which this method is well suited: linear eigenvalue problems generated from non-selfconsistent electronic structure calculations.
Biochemical genetics of mitochondrial biogenesis

Abstract Considerable success in understanding the biogenesis of mitochondria has been achieved by a combined biochemical and genetic attack.
Refinement of Netropsin Bound to DNA: Bias and Feedback in Electron Density Map Interpretation

The X-ray crystal structure of the complex of the B-DNA dodecamer CGCGAATTCGCG with the antitumor drug netropsin has been reexamined to locate the drug accurately for computer-based drug design. The optimum solution is with the drug centered in the AATT region of the minor groove, making three good bifurcated hydrogen bonds with adenine N3 and thymine O2 atoms along the floor of the groove. Pyrrole rings of netropsin are packed against the C2 positions of adenines, leaving no room for the amine group of guanine and, hence, providing a structural rationale for the A.T specificity of netropsin. An alternative positioning in which the drug is shifted along the minor groove by ca. one-half base pair step is rejected on the basis of free R factor calculations and the appearance of the original drug-free difference maps. Final omit maps, although of more pleasing appearance, are not a dependable means of discriminating between right and wrong structures. The shifted alternative drug position ignores potential hydrogen bonding along the floor of the groove, provides no explanation for netropsin's observed A.T specificity, and is contradicted by NMR results [Patel, D. J. (1982) Proc. Natl. Acad. Sci. U.S.A. 79, 6424].
Helpful and unhelpful therapy experiences of LGBT clients

The purpose of this study was to identify a broad range of variables that characterize the helpful and unhelpful therapy experiences of lesbian, gay, bisexual, and transgender (LGBT) individuals. Interviews were completed with a diverse sample of 42 LGBT individuals who have been in therapy, and a content analysis was conducted. Results indicated that basic counseling skills and relationships were key determinants of the quality of LGBT clients' therapy experiences. Also important to the helpfulness of the therapy experience were therapist variables such as professional background and attitudes toward client sexual orientation/gender identity; client variables such as stage of identity development, health status, and social support; and environmental factors such as confidentiality of the therapy setting.
Regulator Characteristics: A Conparision of Two Speed Regulations

The importance of the transient characteristics of analog regulators used on paper machine drives is shown. The speed regulator was chosen as a model since it is the regulator that is most often used. Two different forms of speed regulators were used to demonstrate the differences between different forms of regulators with comments on these differences. A program from the General Electric time-sharing system was used to simulate the two speed regulators, subjecting the regulators to changes in reference and load to determine their transient performance characteristics. The traces of the regulated values are discussed as to their behavior and possible effects when used as a regulator on a paper machine drive.
Postischemic Estrogen Reduces Hypoperfusion and Secondary Ischemia After Experimental Stroke

Background and Purpose—Estrogen is a known neuroprotective and vasoprotective agent in experimental cerebral ischemia. Preischemic steroid treatment protects animals of both sexes from focal cerebral ischemia. This study determined whether intravenous estrogen acts as a vasodilator when administered on reperfusion and whether the resulting increase in cerebral blood flow (CBF) provides tissue protection from middle cerebral artery occlusion. Methods—Adult male Wistar rats were treated with reversible middle cerebral artery occlusion (2 hours), then infused with intravenous estrogen (Premarin; 1 mg/kg) or vehicle during the first minutes of reperfusion (n=15 per group). Cortical laser-Doppler flowmetry was used to assess adequacy of occlusion. Ischemic lesion volume was determined at 22 hours after occlusion by 2,3,5-triphenyltetrazolium chloride staining and image analysis. Cortical and striatal CBF was measured by 14[C]iodoantipyrine autoradiography at 10 (n=10) or 90 (n=11) minutes of reperfusion. Resul...
Fabrication of aligned and molecularly oriented electrospun polyacrylonitrile nanofibers and the mechanical behavior of their twisted yarns

Abstract The fiber spinning technique of electrospinning was optimized in order to prepare unidirectional aligned, structurally oriented, and mechanically useful carbon precursor fibers with diameters in the nanoscale range. The fiber spinning velocity and fiber draw ratio was measured to be between 140 and 160 m/s and 1:300,000, respectively, for fibers spun from 10 wt% polyacrylonitrile (PAN) solutions with dimethylformamide (DMF). A high-speed, rotating target was used to collect unidirectional tows of PAN fibers. Aligned and (+) birefringent fibers with diameters between 0.27 and 0.29 μm (FESEM) were collected from electrospinning 15 wt% PAN in DMF solutions at 16 kV onto a target rotating with a surface velocity between 3.5 and 12.3 m/s. Dichroism measurements (Polarized FTIR) of the nitrile-stretching vibration show an increase in the molecular orientation with take-up speed. Wide angle X-ray diffraction patterns (WAXD) show equatorial arcs from the (10 1 0) reflection at d∼5.3 A and (1120) reflection at d∼3.05 A . A maximum chain orientation parameter of 0.23 was determined for fibers collected between 8.1 and 9.8 m/s. Twisted yarns of highly aligned PAN nanofibers with twist angles between 1.1 and 16.8° were prepared. The ultimate strength and modulus of the twisted yarns increase with increasing angle of twist to a maximum of 162±8.5 MPa and 5.9±0.3 GPa, respectively, at an angle of 9.3°.
Pulsed laser techniques for solar cell processing

Q-switched lasers can serve as energy sources to replace conventional high-temperature furnaces in p-n junction formation in solar cells. They have been used to anneal ion-implantation damage, to produce laser-assisted dopant diffusion, and to regrow doped amorphous layers deposited on single-crystal Si substrates. It has been demonstrated that all these methods are suitable candidates for the processing of high-efficiency Si solar cells. Because they provide ultrarapid heating and cooling of the near-surface region, these laser techniques can be used for p-n junction formation in thin-film polycrystalline material to prevent enhanced dopant diffusion along grain boundaries and for compound semiconductors, such as GaAs, to avoid the need for surface encapsulation during the annealing of ion implantation damage. Defects in the near-surface region such as the "dead layer" produced by conventional high-temperature diffusion can be completely removed by laser irradiation.
Effects of Particle Size Distribution on Opacity Curves of Protoplanetary Disks around T Tauri Stars

Abstract A new interpretation for observed opacity indices at submillimeter- and millimeter-wavelength regions of circumstellar disks around T Tauri stars is presented. Recent photometric observations of T Tauri stars at submillimeter and millimeter wavelength regions by Beckwith and Sargent (1991, Astrophys, J. 381, 250-258) have revealed that power law indices β of frequency dependence of particle opacities in circumstellar disks around T Tauri stars are 0-1; and these values of β are lower than the interstellar value of β ≅ 2. There is distinct difference in β between interstellar and circumstellar dust particles. We have found that the particle growth can explain this difference in observed opacity indices β without considering any change in composition. That is, the interstellar matter is so sparse that particles will rarely collide with each other and will hardly grow, but in denser environments such as circumstellar disks around T Tauri stars particles will grow through coagulation by mutual collisions; this accounts for the distinct difference in β. We performed the Mie calculations to obtain the particle opacity curves of sufficiently grown dust particles on the order of centimeters or more in addition to submicrometer-sized dust particles, composed of the usual dielectric crystalline materials of silicate and H2O-ice mixture assuming the solar elemental abundance; we found that the low β can be realized as a result of the superposition of small particles of β ≅ 2 (Rayleigh scattering regime) and large particles of β ≅ 0 (geometrical optics regime). Furthermore, we show that dust particles with some size distributions (a power law size distribution with an exponent of 3.5 or less and minimum and maximum cut-off radii of 0.01 μm and 0.1-10 cm, respectively) produce larger opacities at submillimeter- and millimeter-wavelength regions than the standard value of particle opacity (Hilde-brand, 1983, Q. J. R. Astron. Soc. 24, 267-282), from which we can estimate typical disk masses as low as minimum-mass solar nebula models. Also we can show that dust particles with such size distributions give, at the same time, opacities consistent with a "turnover" around λ = 100μm for the observed spectral energy distributions of circumstellar disks around some typical T Tauri stars.
Isolation and analysis of mutants of Pseudomonas aeruginosa unable to assimilate nitrate.

Pseudomonas aeruginosa can reduce nitrate to nitrite and evenutally to nitrogen gas by the denitrification pathway, thereby providing the organism with a mode of respiration and ATP generation in the absence of oxygen. P. aeruginosa can also reduce nitrate to nitrite through an assimilatory pathway that provides the cell with reduced nitrogen for biosyntheses. In order to establish whether this organism synthesizes a single nitrate reductase protein that functions in both pathways, or produces one for each pathway, we isolated mutants blocked in the assimilation of nitrate. These mutants are unaffected in the reduction of nitrate be the denitrification pathway, although they produce low or undectable levels of assimilatory nitrate reductase. On the basis of transductional analysis, the mutations were found to be distributed among four genes designated nasA, nasB, nasC, and nasD. Shifting a nasA mutant from anaerobic to aerobic growth eliminated the culture's ability to reduce nitrate, i.e. the anaerobic nitrate reductase cannot function in the presence of oxygen. Thus P. aeruginosa can synthesize two distinct proteins which reduce nitrate to nitrite: an assimilatory nitrate reductase and a dissimilatory nitrate reductase. If conditions of growth are fully aerobic, the latter is not synthesized and does not function. The former, synthesized under the control of at least four genes, is repressed by readily available nitrogen sources.
Distribution of ITPA P32T alleles in multiple world populations

Dose-limiting toxicity from azathioprine treatment affects up to 37% of patients. Screening for thiopurine methyltransferase (TPMT) polymorphisms will prospectively identify approximately 10% of patients. Recently, a polymorphism in the inosine triphosphate pyrophosphatase gene (ITPA) has been associated with severe azathioprine toxicity. We demonstrate here that this proline to threonine substitution at codon 32 in the ITPA gene is found at low frequency in Central/South American populations (1–2%), at a constant frequency across Caucasian and African populations (6–7%), and is highest in Asian populations (14–19%). This data is consistent with previously described allele frequencies in other Caucasian (7%), African (5%), and Asian (11–15%) populations. This data provides a foundation on which prospective screening studies can be planned to identify patients at risk for severe toxicity from azathioprine therapy.
The uranium monocarbide-plutonium monocarbide system

Abstract The (U, Pu)C phase field of the U-Pu-C ternary system for temperatures below 635° C has been constructed from metallographic and X-ray diffraction data. Uranium monocarbide forms a complete series of solid solutions with plutonium monocarbide. The (U, Pu) C phase is stoichiometric as regards its carbon content in a composition range from 0 to 35 atomic percent Pu. With a further increase in Pu content it deviates from ideal stoichiometry toward greater metal-to-carbon ratios to form the defect (U, Pu) C phase. Pu expands the unit cell of the monocarbide over the composition range in which it retains its stoichiometric character. In the region of the defect structure the lattice parameter decreases with increasing Pu content, the extent of the decrease being dependent upon the C content. Metallographic observations on cast alloys show that a transition in the microstructures occurs at about 10 atomic percent Pu: Alloys containing less Pu show a homogeneous carbide phase while alloys of higher Pu content have a cored carbide phase.
Modifications to improve the accuracy of a four-ball test apparatus

The four-ball wear test machine is one of the most widely used tribological tools in both research and industry. In general, the test geometry is self-aligning and minimises the opportunity for random variation. Nonetheless, accurate control of the test parameters remains vital to repeatability and reproducibility. The present paper details a number of modifications to a commercially available test apparatus that have been found to improve accuracy. The applied load on some apparatus was found to vary from the correct value, probably due to frictional drag in the loading system. A feedback control loop was designed and fitted to the applied load mechanism, which resulted in significantly improved accuracy. Finally, the apparatus was fully automated, with complete computer control of all test parameters. Under this, following cleaning and assembly of the test specimens, the required test procedure could be selected from a menu of standard methods, and the computer program then adjusted the test parameters according to the method selected, greatly reducing the possibility of operator error.
Racial-Ethnic Differences in Subjective Survival Expectations for the Retirement Years:

Prior research finds a race anomaly in subjective life expectancy such that Blacks expect to live longer than Whites even though their actual life expectancy is lower, but it does not include other racial-ethnic groups. Using data from the 1998 Health and Retirement Study (n = 8,077), the authors find that the race anomaly in subjective survival expectations can be extended to Mexican Americans: Mexican Americans, regardless of their nativity, expect a lower chance of living to ages 75 and 85 than do Whites net of age and gender even though their actual life expectancy is higher. In addition, foreign-born Mexican Americans expect a lower chance of survival to older ages than native-born Mexican Americans, which is also opposite of actual mortality patterns.We also find that education and wealth interact with race-ethnicity to influence subjective survival expectations.
Safe use of heparin-coated bypass circuits incorporating a pump-oxygenator

Durable, covalently bonded, heparin-coated cardiopulmonary bypass (CPB) circuits with oxygenators have been developed. Proposed advantages of heparin-coated CPB circuits include improved biocompatibility and thromboresistance. The purpose of this study was to evaluate our experience with heparin-coated CPB circuits in 20 patients. Heparin was given to maintain an activated clotting time equal to or greater than 200 seconds, while flow rates were kept equal to or greater than 2 L/min. Indications for use of this circuit included recent stroke, posttraumatic injuries, recent gastrointestinal bleeding, protamine allergies, combined cardiac and noncardiac procedures, and ventricular assist. Mean heparin dosage was 0.50 +/- 0.18 mg/kg and protamine dosage was 57.14 +/- 39.36 mg. Postoperative blood loss and transfusion requirements were minimal. Postoperative complement levels of C3a and C5a were normal, suggesting excellent biocompatibility. There were no deaths or perioperative complications. Heparin-coated CPB circuits using a pump oxygenator can be used safely with low-dose heparin administration in select patients requiring CPB.
Maternal attachment, depression, and body dissatisfaction in pregnant women

Maternal attachment, or the affiliation a mother feels towards her child, is an important predictor of maternal health and fetal/infant outcomes. Thus, it is important to identify psychological factors which may impact maternal attachment. This study examined associations among maternal attachment, depression, and body dissatisfaction (BD) throughout weeks of pregnancy. Pregnant women (n = 196) were recruited to complete a self‐report questionnaire about their experiences during pregnancy. There was no direct association between maternal attachment and BD. However, BD moderated the association between maternal attachment and weeks of pregnancy, and this association was not mediated by depression. High BD may contribute to poorer maternal health and poorer fetal outcomes through blunted growth of maternal attachment during pregnancy. Thus, high BD may be an important target for intervention in women during pregnancy. Future studies should examine longitudinal associations among these variables throughout t...
The role of inter-α-trypsin inhibitor and other proteinase inhibitors in the plasma clearance of neutrophil elastase and plasmin

Abstract The plasma clearance of neutrophil elastase, plasmin, and their complexes with human inter-α-trypsin inhibitor (IαI) was examined in mice, and the distribution of the proteinases among the plasma proteinase inhibitors was quantified in mixtures of purified inhibitors, in human or murine plasma, and in murine plasma following injection of purified proteins. The results demonstrate that IαI acts as a shuttle by transferring proteinases to other plasma proteinase inhibitors for clearance, and that IαI modulates the distribution of proteinase among inhibitors. The clearance of IαI-elastase involved transfer of proteinase to α 2 -macroglobulin and α 1 -proteinase inhibitor. The partition of elastase between these inhibitors was altered by IαI to favor formation of α 2 -macroglobulin-elastase complexes. The clearance of IαI-plasmin involved transfer of plasmin to α 2 -macroglobulin and α 2 -plasmin inhibitor. Results of distribution studies suggest that plasmin binds to endothelium in vivo and reacts with IαI before transfer to α 2 -macroglobulin and α 2 -plasmin inhibitor. Evidence for this sequence of events includes observations that plasmin in complex with IαI cleared faster than free plasmin, that plasma obtained after injection of plasmin contained a complex identified as IαI-plasmin, and that a murine IαI-plasmin complex remained intact following injection into mice. Plasmin initially in complex with IαI more readily associated with α 2 -plasmin inhibitor than did free plasmin.
Suprascapular neuropathy after distal clavicle excision

Two cases of suprascapular neuropathy after excision of the distal clavicle are reported. Both patients were treated successfully with neurolysis of the suprascapular nerve starting at the upper trunk of the brachial plexus. Anatomic dissections revealed that the suprascapular nerve is quite close (<1.4 cm) to the posterior aspect of the distal clavicle, within 2 to 3 cm of the acromioclavicular joint. To avoid the complication of suprascapular neuropathy that could be associated with this close relationship, it is recommended that no more than 1 cm of the distal clavicle be removed posteriorly. It is also recommended that minimal periosteal elevation should be performed on the posteroinferior border of the distal clavicle.
An encyclopaedia of sexuality

Abstract Primate Sexuality. Comparative Studies of the Prosimians, Monkeys, Apes and Human Beings by Alan F. Dixson, Oxford University Press, 1998. £75.00 hbk, £32.50 pbk (656 pages) ISBN 0 19 850183 8/0 19 850182 X
ED evaluation of infants after an apparent life-threatening event

The objective of this study was to determine the rate of positive ED diagnostic evaluations and significant interventions during the hospitalization of infants after an apparent life-threatening event (ALTE). The study was performed at a single, tertiary care children's hospital. Patients under 6 months of age were identified for a potential ALTE from the ED chief complaint log. The charts of patients meeting the definition of an ALTE were abstracted for data pertaining to the patient's history, physical examination, ED diagnostic evaluation, and admission. The yield of the ED diagnostic evaluation and hospitalization was noted. A positive ED evaluation was defined as a diagnostic intervention that resulted in a specific treatment for a defined condition. Significant medical interventions were derived from a validated instrument assessing the risk of admission for pediatric patients presenting to an ED. Such interventions included, but were not limited to, parenteral antibiotics for documented infections, supplemental oxygen, endotracheal intubation, airway suctioning, and intensive-care unit admission. Over a 5-year period with 253,408 patient visits, 523 patents met the initial search criteria for a potential ALTE. From this group, 483 charts were reviewed (92.4%) and 150 patients met the definition for an ALTE. The mean age of the patients was 61.7 days and 115 (76.7%) were admitted. Of the patients with an ALTE, 122 patients had ED diagnostic tests performed and three had a positive result (2.5%; 95% confidence interval [CI]; 0.5-7.0). The rate of significant medical interventions among admitted patients was 7.% (9 of 115, 95% CI, 3.6-14.3). No patients with a positive ED diagnostic evaluation were discharged from the ED. Risk factors for significant medical interventions included prematurity, a positive medical history, and age >60 days. The overall rate of either positive ED diagnostic evaluations or significant medical interventions during hospitalizations of infants after an ALTE is low. A majority of these patients can be best managed with a limited ED diagnostic evaluation and a period of observation.
Step-flow growth of ZnO(0 0 0 1) on GaN(0 0 0 1) by metalorganic chemical vapor epitaxy

Abstract We studied the properties of 500–900 nm thick ZnO(0 0 0 1) layers grown by metalorganic chemical vapor deposition on GaN(0 0 0 1) templates. A two-step growth process was employed where a buffer layer was first grown at 350 – 400 ∘ C . The temperature was then ramped up to 750 – 950 ∘ C for the growth of the epitaxial layer. Atomic force micrographs over a 20 × 20 μ m 2 area revealed locally straight steps, indicating step-flow growth. The root-mean-square roughness was less than 2.6 nm. Hexagonal pits were also observed with a pit density of 7.5 × 10 5 – 2.1 × 10 8 cm - 2 . The full width at half maximums of ω -scans across the symmetric (0 0 0 2) and the ( 2 0 2 ¯ 1 ) reflections were as narrow as 0 . 091 ∘ and 0 . 159 ∘ , respectively. Reciprocal space maps showed that the ZnO films were fully relaxed. Transmission electron microscopy revealed that the defects were mainly of mixed or pure edge dislocation type. No pure screw dislocations or stacking faults were observed.
Retention of hemopoiesis in tail vertebrae of newborn rats

In newborn rats, the marrow cavity of tail vertebrae is hemopoietic and contains no adipose tissue. The latter develops soon after birth to replace the hemopoietic tissue within the nonexpansile volume of the marrow cavity. By transposing the tail into the warmer environment of the abdomen, hemopoiesis was retained, and the development of adipose tissue was prevented in the transposed segment, when the operation was done in preweanling but not in adult animals. Systemic stimuli of erythropoiesis (phlebotomy, induced hemolysis) acted synergistically with the temperature increment to retain hemopoiesis. The findings support the concept that adipose cells in the yellow marrow are relatively stable and once developed, they are not readily mobilized. The findings may also explain the discrepancies in the results obtained by rat tail transposition.
Modelling of the Supercritical Fluid Extraction of Monocrotaline from Crotalaria Spectabilis

Abstract In our extractions of Crotalaria spectabilis with supercritical carbon dioxide and carbon dioxide-ethanol mixtures, we observed history-dependent extraction, possible monocrotaline-lipid fluid phase repulsive interactions and cosolvent retention-release phenomena. In this work, we have developed a solid-to-fluid phase mass transfer model to explain the history dependence of the concentration, a thermodynamic model to fit the experimental equilibrium solubility, and a dynamic model to explain the complex concentration-history data observed in the presence of the cosolvent.
Proper government of antecedentless VP in English and Spanish

It has been argued that null VP structures in English occur where they are properly governed by INFL. Proper government was shown to be satisfied by INFL where it is lexically headed and it fully θ-marks VP: that is, it both assigns a θ-role to VP and assigns a referential index to VP in the form of identification for a time — a value for the feature [PAST]. This latter requirement, which is not fully met when INFL is [-TENSE], accounts for the restricted distribution of null VP in infinitives. In clauses with auxiliaries, Head-Head Agreement allows the Minimality condition to be observed, and allows a non-sister of INFL (or of perfectivehave) to be θ-governed.
Structural transitions, melting, and intermediate phases for stripe- and clump-forming systems

We numerically examine the properties of a two-dimensional system of particles which have competing long-range repulsive and short-range attractive interactions as a function of density and temperature. For increasing density, there are well-defined transitions between a low-density clump phase, an intermediate stripe phase, an anticlump phase, and a high-density uniform phase. To characterize the transitions between these phases we propose several measures which take into account the different length scales in the system. For increasing temperature, we find an intermediate phase that is liquidlike on the short length scale of interparticle spacing but solidlike on the larger length scale of the clump, stripe, or anticlump pattern. This intermediate phase persists over the widest temperature range in the stripe phase when the local particle lattice within an individual stripe melts well below the temperature at which the entire stripe structure breaks down, and is characterized by intrastripe diffusion of particles without interstripe diffusion. This is followed at higher temperatures by the onset of interstripe diffusion in an anisotropic diffusion phase and then by breakup of the stripe structure. We identify the transitions between these regimes through diffusion, heat capacity, and energy fluctuation measurements and find that within the intrastripe liquid regime, the excess entropy goes into disordering the particle arrangements within the stripe rather than affecting the stripe structure itself. The clump and anticlump phases also show multiple temperature-induced diffusive regimes which are not as pronounced as those of the stripe phase.