cssi/SciSciGPT-SciSciNet huggingface dataset:
Uterine stromal sarcoma cell line. A cytogenetic and electron microscopic study.

Abstract Uterine sarcomas constitute approximately 3% of all malignant uterine corpus tumors. Of these, the tumors that originate solely in the stromal elements of the uterine wall are relatively infrequent and have not been well characterized cytogenetically. We report data from a low-grade endometrial stromal sarcoma both at the time of resection and after months in long-term tissue culture. Cytogenetic analysis showed a clonal population of cells with an abnormal karyotype of 46,XX,del(5)(q31.1), der(7)t(6;7)(p21;p22) which remained unchanged in long-term culture. Electron microscopy suggests that these cells are similar to other neoplastic cells in having immature-appearing nuclei surrounded by a relatively mature cytoplasm (with well-developed organelles). Determination of the specificity of these observations must await study of additional stromal sarcomas.
The structure of the oxidized form of clostridial flavodoxin at 1.9-A resolution.

Abstract An electron density map of the oxidized form of flavodoxin from Clostridium strain MP has been calculated to a resolution of 1.9 A employing isomorphous and anomalous scattering data from two heavy atom derivatives, Smiii and Aui. In the region from 3.0 to 1.9 A, the largest structure amplitudes (85% of the total | F | s) have been included in the computation. The over-all figure of merit is 0.808. The molecular model resulting from interpretation of this map has a chain length of 138 residues, in accord with the sequence (Tanaka, M., Haniu, M., Yasunobu, K. T., and Mayhew, S. G. (1974) J. Biol. Chem. 249, 4393–4396). As reported earlier, the molecule possesses a high degree of secondary structure, including a central parallel sheet and four helices. More than 70% of the residues appear to participate in backbone hydrogen bonding. Atomic coordinates, incorporating the sequence data, have been optimized by use of Diamond's model-building program. The flavin mononucleotide prosthetic group adopts a somewhat extended conformation. As expected for the oxidized state, the isoalloxazine ring is planar. It is partly shielded from solvent by a tryptophan residue and interacts on its inner surface with methionine. Protein atoms are also in appropriate positions for interaction with atoms N-1, O-2, and N-3 of the flavin ring, but N-5 appears too far removed to form a hydrogen bond with the apoprotein. The ribityl phosphate moiety also makes multiple contacts with protein groups. Two of the three O' oxygens are in positions where they may participate in hydrogen bonding; the phosphate is closely surrounded by four hydroxyamino acids and four backbone NH groups. However, the prosthetic group is accessible on one side to solvent. Peaks likely to represent solvent can be observed near the dimethylbenzene end of the isoalloxazine ring and adjacent to the 3'-ribityl oxygen. While the mutual arrangement of protein and ribityl phosphate is nearly identical with that found by Watenpaugh et al. (Watenpaugh, K. D., Sieker, L. C., Jensen, L. H., LeGall, J., and Dubourdieu, M. (1972) Proc. Nat. Acad. Sci. U. S. A. 69, 3185–3188) in Desulfovibrio vulgaris flavodoxin, the orientation and interactions of the flavin ring differ strikingly in the two flavodoxins. The structure of the oxidized form of Clostridium MP flavodoxin is very similar to that deduced earlier for the semiquinone form at 3.25 A, despite large differences in the x-ray intensities (Ri = 0.66).
Preliminary theoretical study on the flashover voltage of polymeric insulators

Presented in this paper are results of a flashover voltage study of polymeric insulating materials using a dynamic model. Since contamination performance of insulators depends both on the soluble (ESDD) and the non-soluble (NSDD) parts of air-borne contaminants deposited on the insulator surface and the nature of the surface, both ESDD/NSDD and surface resistance data have been used for this purpose. Use of surface resistance as an indicator of contamination severity is becoming popular, especially in the case of polymers, because the contaminant is encapsulated by the diffusion of polymeric chains from the bulk to the surface. Model results with good correlation to the experimental data have been obtained. Also reported are model results in close correlation with experimental observations that reflect the recovery characteristics of polymeric samples as a function of time and NSDD.
Metalinguistic explanations and self-reports as triangulation data for interpreting second language sociolinguistic performance

The study reported here explores the use of learners' metalinguistic explanations and self-reports of variable language production as triangulation data for interpreting second language (L2) sociolinguistic performance, focusing on the variable retention versus omission of the negative morpheme ne. Our central argument is that performance data alone are not sufficient for evaluating how L2 learners perceive social and stylistic variation in the language they are studying. To this end, an analysis of data from a variety of sources is presented. The results illustrate how multiple data sources can provide a multidimensional view of sociolinguistic performance that is not necessarily revealed when performance data alone are considered as a single source of analysis. Nous explorons l'utilisation d'explications metalinguistiques et d'auto-rapports de production langagiere variable d'apprenants en tant que donnees de triangulation pour l'interpretation de la performance sociolinguistique en langue seconde, tout en nous concentrant sur la retention et l'omission du morpheme de negation ne. Nous proposons que les donnees de performance ne sont pas suffisantes pour evaluer la comprehension de la variation sociale et stylistique de la part des etudiants dans la langue qu'ils apprennent. A cette fin, une analyse de donnees provenant de diverses sources est presentee. Les resultats montrent comment plusieurs sources de donnees peuvent fournir une perspective multidimensionnelle de la performance sociolinguistique, une perspective qui n'aurait pas ete revelee si nous n'avions considere que les donnees de performance.
Ventilation-perfusion relationships in children with heart disease and diminished pulmonary blood flow.

Pulmonary function of infants and children with diminished pulmonary blood flow was studied by measurement of alveolar ventilation and alveolar-arterial gas tension differences of O2, CO2, and N2. The increased ventilation of these subjects was found to be effective in CO2 elimination (arterial CO2 tension, 31 mm Hg), but there was evidence of considerable unevenness of distribution of ventilation/perfusion ratios (VAQ). A measure of the degree of VA/Q unevenness was obtained by use of the urine-alveolar nitrogen tension difference. It is likely, under the prevailing conditions of hyperventilation and hypoperfusion, that maldistribution of perfusion is the major abnormality. Uneven distribution of perfusion is most probably due to the effects of gravity enhanced by low pulmonary artery pressure and blood flow—an exaggenation of the normal physiologic relative overperfusion of the lower-most parts of the lung.
Operation and theory of a driven single-mode electron cyclotron maser.

A study is made of the operation of the electron cyclotron resonance maser (ECRM), when subjected to an external rf signal. The signal is introduced both via direct injection through a coupling hole in the oscillator and by modulating the electron beam in separate cavities, upstream of the oscillator. Experiments using both one and two ``prebunching'' cavities are reported. It is experimentally found that the gyromonotron, a specific embodiment of the ECRM, can be phase locked by premodulating the electron beam at drive power levels more than two orders of magnitude below that predicted by Adler's widely applicable theory for single-cavity oscillators. A perturbation theory is used to predict the phase-locking frequency band for a gyromonotron with any number of prebunching cavities. The predictions of this theory agree with the experimental results for two- and three-cavity phase locking. An investigation is made into the general amplitude and frequency response of the ECRM to an applied external signal. Experimentally, three distinct regions of qualitatively different ECRM behavior are noted: soft excitation, which is free, self-excited oscillation; hard excitation, where the oscillation requires an external impulse for startup; and amplifier, in which the output power level and frequency are linearly related to the drive in the small-signal regime.
The Ins2Akita mouse as a model of early retinal complications in diabetes.

PURPOSE This study tested the Ins2(Akita) mouse as an animal model of retinal complications in diabetes. The Ins2(Akita) mutation results in a single amino acid substitution in the insulin 2 gene that causes misfolding of the insulin protein. The mutation arose and is maintained on the C57BL/6J background. Male mice heterozygous for this mutation have progressive loss of beta-cell function, decreased pancreatic beta-cell density, and significant hyperglycemia, as early as 4 weeks of age. METHODS Heterozygous Ins2(Akita) mice were bred to C57BL/6J mice, and male offspring were monitored for hyperglycemia, beginning at 4.5 weeks of age. After 4 to 36 weeks of hyperglycemia, the retinas were analyzed for vascular permeability, vascular lesions, leukostasis, morphologic changes of micro- and macroglia, apoptosis, retinal degeneration, and insulin receptor kinase activity. RESULTS The mean blood glucose of Ins2(Akita) mice was significantly elevated, whereas the body weight at death was reduced compared with that of control animals. Compared with sibling control mice, the Ins2(Akita) mice had increased retinal vascular permeability after 12 weeks of hyperglycemia (P < 0.005), a modest increase in acellular capillaries after 36 weeks of hyperglycemia (P < 0.0008), and alterations in the morphology of astrocytes and microglia, but no changes in expression of Muller cell glial fibrillary acidic protein. Increased apoptosis was identified by immunoreactivity for active caspase-3 after 4 weeks of hyperglycemia (P < 0.01). After 22 weeks of hyperglycemia, there was a 16.7% central and 27% peripheral reduction in the thickness of the inner plexiform layer, a 15.6% peripheral reduction in the thickness of the inner nuclear layer (P < 0.001), and a 23.4% reduction in the number of cell bodies in the retinal ganglion cell layer (P < 0.005). In vitro insulin receptor kinase activity was reduced (P < 0.05) after 12 weeks of hyperglycemia. CONCLUSIONS The retinas of heterozygous male Ins2(Akita) mice exhibit vascular, neural, and glial abnormalities generally consistent with clinical observations and other animal models of diabetes. In light of the relatively early, spontaneous onset of the disease and the popularity of the C57BL/6J inbred strain as a background for the generation and study of other genetic alterations, combining the Ins2(Akita) mutation with other engineered mutations will be of great use for studying the molecular basis of retinal complications of diabetes.
In vitro fatty acid oxidation rates in rat heart and liver

Abstract Experiments were conducted to test the effects of age, sex, and level and type of dietary fat on the oxidation rates of carboxyl- and uniformly-labeled linoleate, oleate and palmitate. There were no significant differences due to age, sex, nor diet alone but a statistically significant (P palmitate ⩾ oleate. Incubation conditions, tissue interactions, position of label and end products recovered are discussed in relation to interpretation of results in studies of fatty acid metabolism.
Vibration Suppression in a Tension-Aligned Structure Through Sequential Application and Removal of Constraints

We present an efficient method for vibration suppression in a tension-aligned array structure using constraint actuators. The primary role of constraint actuators is to cyclically apply and remove constraints such that vibration energy is efficiently funneled into high-frequency modes of the structure, where it can be dissipated quickly and naturally due to high rates of damping. A cycle of constraint application and removal can never add energy and hence the method can potentially achieve vibration control without accurate knowledge of the system states. The vibration control methodology is applied to a tension-aligned array structure supported by a structure in compression. Our approach for vibration suppression has the potential to positively influence the development of tension-aligned architectures which are contemplated for large precision apertures in space.Copyright © 2012 by ASME
129I interlaboratory comparison

An interlaboratory comparison exercise for 129I has been organized and conducted. A total of seven laboratories participated in the exercise to either a full or limited extent. In the comparison, a suite of 11 samples was used. This suite of standards contained both synthetic “standard type” materials (i.e., AgI) and environmental materials. The isotopic 129I127I ratio of the samples varied from 10−8 to 10−14. Preliminary results of the comparison are presented.
Genetic heterozygosity in a natural population of Mus musculus assessed using two-dimensional electrophoresis.

Since the introduction of gel electrophoresis to population genetics, estimates of genie heterozygosity at allozyme loci have been made for many organisms1. However, attempts to extend the range of proteins surveyed2–4 have been hampered by concern that there may have been bias in the loci sampled: nearly all proteins for which population data are available are soluble in low-salt extracts and most are enzymes belonging to particular groups such as the nonspecific esterases and phosphatases, various dehydrogenases and the enzymes of the glycolytic pathways and the citric acid cycle. Until recently, there were no techniques for estimating protein variation which were without such bias. Two-dimensional gel electrophoresis5, however, offered hope of overcoming this bias, and it has proved useful for the resolution of proteins in crude homogenates and for estimating genetic variation6–9. We have examined heterozygosity in a wild population of the house mouse (Mus musculus) by means of two-dimensional electrophoresis of whole kidney. As we report here, the observed level (2%) is substantially below the level detected by starch gel electrophoresis10–12. Our results corroborate similar differences observed in Drosophila6 and man7,9.
Spermatophore Generation Times in Penaeus setiferus, P. vannamei, and P. stylirostris

Spermatophore development times were studied in three species of penaeid shrimp, Penueus setifcrus, P. vannumei, and P. stylirosrris. In the terminal ampoule, the progression of spermatophore formation occurred in 4 stages (I-IV). The duration of each stage varied with species and ablation state. In unablated males, with spermatophores manually or electrically removed, structnrally complete spermatophores containing high numbers of morphologically normal sperm were formed in 2–4 days for P. vannamei, 4–6 days for P. stylirostris and 5–7 days for P. setiferus. Unilateral eyestalk ablation of P. setiferus accelerated spermatophore production time by approximately 2 days, and significantly increased spermatophore weight and sperm count without affecting sperm quality. Spermatophore removal techniques had little effect on development time in P. vannamei. However, in P. setiferus, new spermatophores were produced faster in males mating naturally than in those males whose spermatophores were removed electrically.
Piperidine-Functionalized Supports Sequester Atrazine from Solution

To achieve irreversible (covalent) capture of monochlorotriazine herbicides such as atrazine, three commercially available poly(styrene) resins (Janda Jels) that vary in size were modified with reactive isonipecotic acid groups. The materials were characterized using the Kaiser test, infrared (IR) spectroscopy, and titration experiments that indicated the relative number of accessible nucleophiles. Sequestration of atrazine from aqueous solutions using these polymers was monitored using liquid chromatography−mass spectrometry. Large (50−100 mesh) and medium (100−200 mesh) resins remove all detectable traces of atrazine from water at similar rates, whereas the smallest resin (200−400 mesh) removes the herbicide at a slower rate. Generally, the sequestration of atrazine by reactive, nucleophilic resins seems to be a suitable strategy for additional inquiry, particularly as an alternative to the current method of wastewater treatmentactivated charcoal.
Repetitive Pulse Accelerator Technology for Light Ion Inertial Confinement Fusion

Successful ignition of an inertial confinement fusion (ICF) pellet is calculated to require that several megajoules of energy be deposited in the pellet's centimeter-sized shell within 10 ns. This implies a driver power of several hundreds of terawatts and power density around 100 TW/cm2 . The Sandia ICF approach is to deposit the energy with beams of 30 MV lithium ions. The first accelerator capable of producing these beams (PBFA II, 100 TW) will be used to study beam formation and target physics on a single pulse basis. To utilize this technology for power production, repetitive pulsing at rates that may be as high as 10 Hz will be required. This paper will overview the technologies being studied for a repetitively pulsed ICF accelerator. As presently conceived, power is supplied by rotating machinery providing 16 MJ in 1 ms. The generator output is transformed to 3 MV, then switched into a pulse compression system using laser triggered spark gaps. These must be synchronized to about 1 ns. Pulse compression is performed with saturable inductor switches, the output being 40 ns, 1.5 MV pulses. These are transformed to 30 MV in a self-magnetically insulated cavity adder structure. Space charge limited ion beams are drawn from anode plasmas with electron counter streaming being magnetically inhibited. The ions are ballistically focused into the entrances of guiding discharge channels for transport to the pellet. The status of component development from the prime power to the ion source will be reviewed.
A source of bias in the analysis of single channel data: assessing the apparent interaction between channel proteins

A recent study of single sodium channel currents in neuroblastoma cells suggested interaction between ion channels in close proximity to one another (T. Kiss and K. Nagy, Eur. Biophys. J. 12, 13, 1985). The opening of one channel appeared to affect the likelihood that neighboring channels might open. Some of the conclusions were based on the analysis of observed channel openings that were segregated depending on whether one channel or more than one channel was open at the same time. We hypothesized that the longer one channel remained open, the more likely another channel operating independently, would open, thereby creating the impression of an apparent coupling of channel behavior. We performed simulations and measurements of single sodium channel currents to determine whether the technique of event segregation could account for apparent channel interactions. The simulations showed that the segregation of overlapping (more than one channel open at the same time) and nonoverlapping events led to a bias in the estimated open time and the derived closing rate. To avoid the bias, we found that random pairing of opening and closing events provided an unbiased estimate of the mean closing rate. Using this random assignment approach, we showed that the mean closing rate of single sodium channels in neonatal rat myocytes decreased with depolarization over a limited range of membrane potential. This suggested that the underlying closure mechanism(s) was voltage dependent. From the analysis of open times, we found no evidence for channel interaction in the time scale of tens of milliseconds. Depolarizing steps without events occurred in runs suggesting the existence of long-lived shut state(s). Double pulse experiments with the prepulse and test pulse above threshold showed significant inactivation of channels that did not open. The rate of inactivation of shut channels was substantially slower than the closure rate of open channels. The rate of inactivation of cardiac sodium channels appeared to be strongly dependent on the initial channel state.
Theory of the time-dependent-thermal-lensing (TDTL) technique as used in energy-transfer experiments

Abstract A unified theory of the TDTL technique that incorporates energy-transfer rates, diffusion, and thermal conductivity is presented. In the appropriate limits, the unified approach reduces to simplified theories that have appeared in the literature. Example calculations are given and the physics of the effect is discussed.
Guest Editors' Introduction: Special Issue on Data-Intensive Computing in the Clouds

Scientific as well as commercial applications generate increasingly large amounts of data, often referred as the “data deluge”, which necessitates collaboration and sharing among the national and international research and industrial organization. Simply purchasing high-capacity, highperformance storage and networking systems and adding them to the existing infrastructure of the collaborating institutions does not solve the underlying and highly challenging data handling problem. Users are often forced to spend a great deal of time and energy on solving basic datahandling issues, such as the physical location of data, how to access it, and/or how to move it to visualization and/or compute resources for further analysis. The management of data resources and
Effect of glycerol and cryopreservation on oocyte penetration by human spermatozoa

A poor penetration rate of glycerol-treated, cryopreserved human spermatozoa as compared to untreated fresh control, was observed in the zona-free hamster oocyte test. Similarly, glycerol treatment of freshly ejaculated spermatozoa depressed the penetration rate unless the culture medium also contained glycerol. Immediately after thawing, glycerol-treated, cryopreserved spermatozoa possessed adequate progressive motility, but their incubation in glycerol-free culture medium caused a severe reduction in motility. Even if the same number of progressively motile, cryopreserved, glycerol-treated spermatozoa as unfrozen spermatozoa were added to the eggs, a much lower penetration rate was obtained by the treated spermatozoa. It is concluded that spermatozoa develop a glycerol dependence and that removal of glycerol from the surrounding medium, as most likely occurs when spermatozoa pass through the cervix, reduces both the motility and the ability of spermatozoa to become capacitated and fuse with oocytes. Thus, glycerol is not an optimal cryopreservative agent. Further, the decreased oocyte penetration rate of glycerol-treated, cryopreserved spermatozoa is due to other factors besides the decrease in sperm motility.
Fluorescence polarization studies of human and rhesus A-I apolipoproteins and their complexes with phosphatidylcholine.

Abstract Human and rhesus A-I apolipoproteins, covalently labelled with dansyl chloride, were used in fluorescence polarization studies of: 1) the monomeric structure of the free proteins in solution; 2) the interaction of the apolipoproteins with sonicated egg phosphatidylcholine; and 3) the size of the saturated complexes of protein with phospholipid. The results indicate that both monomeric apolipoproteins have relatively rigid, yet asymmetrical structures, with Stokes radii of 24.2 ± 0.5 A, in neutral aqueous solutions. Axial ratios are of the order of 6 1 or 4 1 for hydrated, prolate or oblate ellipsoids, respectively. A molar excess of about 200 phosphatidylcholine molecules are required to saturate each apolipoprotein. At saturation, the complexes with both proteins have Stokes radii of 40.6 ± 1.7 A. Since the radius of phosphatidylcholine vesicles is around 125 A, we conclude that the complexes are relatively small structures derived from disruption of the lipid vesicles, rather than from adsorption of the proteins on intact vesicles.
Analytic bounds for solutions of a class of boundary value problems in physiology

Abstract A method of obtaining pointwise upper and lower bounds for the solutions of a general class of nonlinear boundary value problems is discussed. As a illustrative example, this method is shown to yield sharp polynomial approximations to the solution of the oxygen diffusion problem in spherical cells with oxygen uptake by Michaelis-Menten kinetics.
Caspase-1 recognizes extended cleavage sites in its natural substrates

Abstract Objective The preferred amino acids in the proteolytic sites have been considered to be similar between caspase-1 and caspase-9, which do not support their differential functions in inflammatory pyroptosis and apoptosis. We attempted to solve this problem. Methods We analyzed the flanking 20 amino acid residues in the cleavage sites in 34 caspase-1 and 11 capase-9 experimentally identified substrates. Results This study has made the following findings: first, we verified that caspase-1 and caspase-9 shared 100% aspartic acid in the P1 position. However, the structures in the cleavage sites of most caspase-1 substrates are different from that of caspase-9 substrates in the following three aspects, (a) the amino acid residues with the statistically high frequencies; (b) the hydrophobic amino acid occurrence frequencies; and (c) the charged amino acid occurrence frequencies; second, the amino acid pairs P1–P1′ are different; third, our identified cleavage site patterns are useful in the prediction for the 91.4% cleavage sites of 35 new caspase-1 substrates. Conclusion Since most caspase-1 substrates are involved in vascular function, inflammation and atherogenesis, our novel structural patterns for the caspases’ substrates are significant in developing new diagnostics and therapeutics.
CENTRAL ROLE OF INSULIN IN GROWTH AND DEVELOPMENT

Abstract Insulin has been shown to have an impact on both prenatal and postnatal growth. Specific mechanisms of insulin action on adipose cell function and lipid storage are well defined. Insulin probably acts in concert with other anabolic factors (i.e., growth hormone and somatomedins) to stimulate muscle protein anabolism and suppress protein catabolism (Figure 2). Insulin also plays a role in energy balance regulation by the hypothalamus, however exact mechanisms of effects on brain metabolism have not been clearly identified.
Poster: retrofitting computer vision libraries for concurrent support on mobile devices

While computer vision algorithms and libraries have enabled and accelerated the adoption of vision processing into mobile and wearable applications, vision is a resource-hungry operation, and is thus not efficient enough to run on multiple applications simultaneously. However, we observe that many vision algorithms share identical sets of frames and features to perform their analyses, computed from the same library calls. Leveraging this observation, we design a split-process architecture to retrofit existing vision libraries to allow applications to transparently share the computational, memory, and energy overhead of vision processing.
Epidemiology of abusive abdominal trauma hospitalizations in United States children

Objectives (1) To estimate the incidence of abusive abdominal trauma (AAT) hospitalizations among US children age 0–9 years. (2) To identify demographic characteristics of children at highest risk for AAT.
“Academic Liaison Offices vs. Technology Transfer Units: Could they form a new joint mechanism towards the exploration of Academic/Research results?”

The effective management of industry/university research linkages has always been a challenge — for both partners. Moreover, a greater understanding is required for the role that these partners can play in developing strong linkages between them, particularly through mechanisms such as liaison offices and technology parks. This paper will examine the role of such mechanisms for the case of Greece. Basing on interviews with individuals in technology transfer process between academia and industry, it will examine the role and function of Academic Liaison Offices and Technology Transfer Units. Moreover, the development of effective strategies which is a matter for serious concern will be proposed in order to bridge the gap between them. Finally, the addressed model, such as a combined bridge linking both partners is to promote the liaison between the two and to overcome the traditional university structures which have not been designed for technology transfer purposes but for research and education only.
EPR and FTIR analysis of the mechanism of H2 activation by [FeFe]-hydrogenase HydA1 from Chlamydomonas reinhardtii.

While a general model of H2 activation has been proposed for [FeFe]-hydrogenases, the structural and biophysical properties of the intermediates of the H-cluster catalytic site have not yet been discretely defined. Electron paramagnetic resonance (EPR) spectroscopy and Fourier transform infrared (FTIR) spectroscopy were used to characterize the H-cluster catalytic site, a [4Fe-4S]H subcluster linked by a cysteine thiolate to an organometallic diiron subsite with CO, CN, and dithiolate ligands, in [FeFe]-hydrogenase HydA1 from Chlamydomonas reinhardtii (CrHydA1). Oxidized CrHydA1 displayed a rhombic 2.1 EPR signal (g = 2.100, 2.039, 1.997) and an FTIR spectrum previously assigned to the oxidized H-cluster (Hox). Reduction of the Hox sample with 100% H2 or sodium dithionite (NaDT) nearly eliminated the 2.1 signal, which coincided with appearance of a broad 2.3–2.07 signal (g = 2.3–2.07, 1.863) and/or a rhombic 2.08 signal (g = 2.077, 1.935, 1.880). Both signals displayed relaxation properties similar to tho...
Leptomeningeal spread of breast cancer: Report of case and review of the literature

Leptomeningeal metastasis--so-called "meningeal carcinomatosis"--of breast carcinoma has become a problem of some magnitude in recent years, in part a result of the increasing use of combination chemotherapy in the treatment of this disease. Early clinical diagnosis, based on the recognition of multifocal neurologic dysfunction, and aggressive therapy combining irradiation to severely symptomatic sites with intrathecal chemotherapy are considered primordial in order to improve the poor prognosis of the untreated lesion. This is especially true in view of the fact that meningeal metastasis often occurs as the sole site of recurrence in an otherwise asymptomatic patient. Hence, relief of neurologic symptoms can provide meaningful palliation and an occasional long-term survivor. If meningeal metastasis continues to increase in breast cancer patients, prophylactic CNS treatment may become a consideration.
A thermodynamic analysis of electricity and hydrogen co-production using a solid oxide fuel cell

This paper presents the electricity and hydrogen co-production concept, a methodology for the study of SOFC hydrogen co-production, and simulation results that address the impact of reformer placement in the cycle on system performance. The methodology is based on detailed thermodynamic and electrochemical analyses of the systems. A comparison is made between six specific cycle configurations, which use fuel cell heat to drive hydrogen production in a reformer using both external and internal reforming options. SOFC plant performance has been evaluated on the basis of methane fuel utilization efficiency and each component of the plant has been evaluated on the basis of second law efficiency. The analyses show that in all cases the exergy losses (irreversibilities) in the combustion chamber are the most significant losses in the cycle. Furthermore, for the same power output, the internal reformation option has the higher electrical efficiency and produces more hydrogen per unit of natural gas supplied. Electrical efficiency of the proposed cycles ranges from 41 to 44%, while overall efficiency (based on combined electricity and hydrogen products) ranges from 45 to 80%. The internal reforming case (steam-to-carbon ratio of 3.0) had the highest overall and electrical efficiency (80 and 45% respectively), but lower second law efficiency (61%), indicating potential for cycle improvements. Copyright © 2006 by ASME.
Effect of Solute Concentration on Sorption of Polyaromatic Hydrocarbons in Soil: Uptake Rates

The effect of solute concentration on sorption kinetics may be a factor in determining bioavailability and transport of organic pollutants in soils and sediments, but there is conflict in the literature over whether sorption is concentration-dependent. Sorption of phenanthrene and pyrene to seven soils ranging in organic carbon (OC) content from 0.18 to 43.9% was studied. Careful analysis revealed that experimentally the normalized rate of approach to equilibrium for compounds exhibiting a concave-down (with respect to the solute concentration axis) nonlinear isotherm increases with concentration. However, the effect is rather small and is most apparent when the fraction of total solute finally taken up by the solid (F) is low. The explanation is rooted in the nonlinearity of the isotherm and the finite-bath condition of the experiment and can be expressed in terms of two opposing effects. On the one hand, the apparent diffusivity of a (concave-down) nonlinearly sorbing compound within particles increases with concentration because its affinity for the solid phase decreases with increasing concentration. On the other hand, rates in finite-bath reactors carried out at the same liquid/solid ratio will suffer from a batch process temporal bias called the "shrinking gradient" effect. It is an artifact of the methodology and is due to gradient driving forces that slow the sorption rate as F declines. In nonlinear cases F declines as concentration increases. The shrinking gradient effect vanishes as the liquid/solid ratio approaches infinity. Although this effect is self-correcting when an appropriate nonlinear diffusion model is applied, consensus about such models has not yet been achieved. To provide bounds for the shrinking gradient effect in finite-bath systems semiempirically, two models that give lower and upper bounds of the characteristic sorption time tau in the limit of infinite bath have been employed: (a) a wetting front model, which assumes sorption is rate-limited by molecular migration, and (b) a fast diffusion model, which assumes a mass-transfer resistance at the sorption site. The results are consistent with an intrinsic positive concentration dependence of sorption kinetics.
Attitude Change Measuring the Effect of an Educational Program

Measurement of attitudes before and after an educational intervention generally reflects both the impact of the session and the fact that the best predictor of attitudes after the session are attitudes before the session. Statistics currently available provide contradictory information; both measures of association and measures of difference are statistically significant. Current tests of the significance of change either have restrictive assumptions or do not take into account people who do not change. A new measure is proposed which incorporates information on amount and direction of change. Delta is calculated from a contingency table of the pre-and postmeasurements. It ranges from + 1, signifying that everyone changed in one direction to -1, that is, everyone changed in the opposite direction, and becomes 0 when there is perfect correlation in scores or equal change in both directions. Delta is useful in assessing which attitudes have been most influenced by the educational intervention.
Analgesic Usage for Low Back Pain : Impact on Health Care Costs and Service Use

STUDY DESIGN Cross-sectional analysis of analgesic use by patients with low back pain (LBP). OBJECTIVES To describe patterns of analgesic use and their cost implications for the use of other care services among individuals with LBP enrolled in a health insurance plan during 2001. It was hypothesized that the use of analgesics would be most frequent among patients with LBP with neurologic findings. SUMMARY OF BACKGROUND DATA National guidelines have recommended analgesics as the primary pharmacologic treatment of LBP. The choice of specific analgesics has major cost and service use implications. METHODS The University of Pittsburgh Health System includes 18 affiliated hospitals, more than 5000 physicians, and a commercial health plan with 255,958 members in 2001. This study uses the System Health Plan's insurance claims database to identify members who had services provided for one of 66 International Classification of Diseases, Version 9, Clinical Modification codes that identify mechanical LBP (n = 17,148). RESULTS In 2001, 7631 (43.5%) members with claims for LBP services had no analgesic pharmacy claims. The other 9517 (55.5%) had analgesics claims costing a total of $1.4 million; 68% of claimants were prescribed an opioid and 58% nonselective nonsteroidal antiinflammatory drugs (NSAID). The costs of opioids, NSAID, and cyclooxygenase-2 selective NSAID for patients with LBP represented 48%, 24%, and 28%, respectively, of total health plan expenditures for all uses of these drugs, including cancer. Opioid use was associated with the high volume usage of LBP care services. Patients with LBP with and without neurologic involvement and those with acquired lumbar spine structural disorders had similar patterns of analgesic use: those with congenital structural disorders were less likely to use analgesics; and those with psychogenic pain and LBP related to orthopedic devices were more likely to use opioids. CONCLUSIONS With this health plan, a high proportion of patients with LBP had claims for opioids during 2001. The use of opioids by patients with LBP represents a major cost for the health plan, and is associated with specific patient characteristics and their use of other LBP services.
Geographical Affinities of the Barro Colorado Island Flora

The flora of Barro Colorado Island was examined for affinities with the floras of Central and South America. Trees, lianas, and epiphytes were treated as separate groups. Distributional classes were established, ranging from species endemic to Panama and those with distributions including both Central and South America as well as the West Indies. The Barro Colorado flora seems to consist of approximately equal numbers of both North (chiefly Central) and South American species. Twelve percent of the Barro Colorado Island species considered in this study are endemic to Panama, and 11% are restricted to Panama and to nearby regions of Colombia and Costa Rica. Trees, lianas, and epiphytes are endemic in roughly an inverse proportion to their ability to be wind-dispersed, with trees showing the highest level of endemism and also having the least significant wind dispersal. About 50% of all species in the study are common to both North and South America, indicating a significant migration of species from both directions. The evidence indicates that most migrations between North and South America were Late Tertiary.
Managed care, mental illness and African Americans: A prospective analysis of managed care policy in the United States

Abstract The shift in health care policy towards managed care is designed to decrease costs and increase health security. In this article, managed care policy and processes are analyzed, using a states‐rights framework, to determine the prospective impact on African Americans with mental illness. Historical and current data on the health status of the American population is presented to show the different patterns of help‐seeking, access, and utilization by race. This data suggests that without cultural guidelines, clinical services for African Americans are likely to increase costs. As a result of the incongruence between managed care goals and processes and the service usage patterns of African Americans, it is concluded that managed care organizations may have limited incentives to service this population. To counteract this tendency, managed care organizations need to develop/apply culturally competent guidelines and clinical standards for this population.
A unified optimization approach for diffusion tensor imaging technique.

Abstract An optimization approach for diffusion tensor imaging (DTI) technique is proposed, aiming to improve the estimates of tensors, fractional anisotropy (FA), and fiber directions. With the simulated annealing algorithm, the proposed approach simultaneously optimizes imaging parameters (gradient duration/separation, read-out time, and TE), b-values, and diffusion gradient directions either with or without incorporating prior knowledge of tensor fields. In addition, the method through which tensors are estimated, least squares in our study, was also considered in the optimization procedures. Monte-Carlo simulations were performed for three different scenarios of prior fiber distributions including fibers orientated in 1 (CONE1) and 3 (CONE3) cone areas (50 tensors orderly oriented within a diverging angle of 20° in each cone) and a uniform fiber distribution (UNIF). In addition, three imaging acquisition schemes together with different signal-to-noise ratios were tested, including M/N = 1/6, 2/12, and 5/30 for each prior fiber distribution where M and N were the number of b = 0 and b > 0 images, respectively. Our results show that the optimal b-value ranges between 0.7 and 1.0 × 109 s/m2 for UNIF. However, the optimal b-value ranges become both higher and wider for CONE1 and CONE3 than that of UNIF. In addition, the biases and standard deviations (SD) of tensors, and SD of FA are substantially reduced and the accuracy of fiber directional estimates is improved using the proposed approach particularly in CONE1 when compared with the conventional approaches. Together, the proposed unified optimization approach may offer a direct and simultaneous means to optimize DTI experiments.
Nitrogen management considerations for landspreading municipal solid waste compost.

Many municipalities have examined composting as an alternative to landfilling for the management of organic solid waste materials. Ultimately these materials will be land-applied and therefore some knowledge of nutrient availability will be necessary to optimize crop yield and minimize environmental risk. Field studies were conducted in 1993 and 1994 on a silt loam and a loamy sand soil in Wisconsin to determine the effect of municipal solid waste compost (MSWC) on corn (Zea mays L.) yield, plant nutrient concentration, and soil nitrate N content. Municipal solid waste composts with ages of 7, 36, and 270 d were applied at rates of 22.5, 45, and 90 Mg ha -1 to small plots. Rates of commercial nitrogen (N) fertilizer, ranging from 0 to 179 kg N ha -1 , were applied to separate plots to determine the N availability from the MSWC. Treatments were applied in the spring and incorporated before planting corn. The 270-d MSWC increased corn whole-plant dry matter and grain yield at each location in both years above the 7- and 36-d MSWC. Rate of MSWC only affected grain yield at the loamy sand site in 1994. Municipal solid waste compost had minimal effect on the levels of plant nutrients in the whole-plant tissue measured at physiological maturity. Nitrate N measured in the top 90 cm of soil was higher throughout the growing season in treatments receiving recommended N fertilizer when compared with any of the MSWC treatments. It was estimated that 6 to 17% of the total N in the 270-d MSWC became available in the first year. The land-application of mature MSWC at the tested rates would be an agronomically and environmentally admissible practice.
FORMATION OF MOLECULAR HYDROGEN FROM METHANE ICE

To study the formation of molecular hydrogen in the wake of the processing of interstellar ices by energetic cosmic-ray particles, we investigated the interaction of energetic electrons, as formed in the track of galactic cosmic-ray particles, with deuterated methane ices (CD4) at 11 K. The energetic electrons mimic energy-transfer processes that occur in the track of the trajectories of energetic cosmic-ray particles; deuterated methane ice was utilized to discriminate the molecular deuterium (m/z = 4) formed during the radiation exposure from the residual molecular hydrogen gas (m/z = 2) released inside the ultrahigh vacuum scattering chamber from outgassing of the stainless steel material. The ices were characterized online and in situ using Fourier transform infrared spectroscopy, while the evolution of the molecular deuterium (D2) into the gas phase was monitored using a mass spectrometer. A mass spectrometric signal proportional to the number density of the deuterium molecules generated inside the ice and released during the irradiation was analyzed kinetically using a set of coupled rate equations. From the fit to the experimental data, we obtain activation energies for the diffusion of atomic deuterium (E 0 = 37 ± 1 meV), and for the desorption of atomic (E 1 = 32 ± 1 meV) and molecular deuterium (E 2 = 32 ± 1 meV). These energies are placed in context and then transferred to atomic and molecular hydrogen to yield astrophysically relevant data. The experimental yield of molecular deuterium is then used to calculate the formation rate of molecular hydrogen due to cosmic-ray interaction with ice-covered grains in dense clouds.
Electrical properties and photoluminescence studies of Ge-implanted GaAs

Thedata presented here show that Ge- implanted GaAs has a complex amphoteric behavior which is controlled by the implantation dose, implantation temperature, and anneal temperature. Annealing was performed with rf plasma deposited Si3N4 as the encapsulant. Implantations at-100° C resulted in p-layers, while those performed at 100° C and above resulted in n-layers regardless of the dose and anneal temperature. Room temperature implants resulted in p- or n-layers depending on the combination of dose and anneal temperature. Electrical activation and carrier mobilities were low for anneal temperatures ≤ 850°C. Low temperature (6 K) photoluminescence indicated that a significant amount of residual damage remained after annealing. Atomic Ge distribution profiles, carrier con-centration profiles, and junction characteristics of Ge-implanted GaAs planar diodes are also presented.
Effect of reproductive status on twinning and on side of ovulation and embryo attachment in mares.

Abstract Brood-farm records were used to test several hypotheses concerning twinning and inequalities in the side of ovulation and embryo attachment. Ovulation occurred more frequently (P 9 32 ) than when the ovulations were synchronous ( 0 19 ). These results support the conclusion that an embryo-reduction mechanism exists in mares for the elimination of excess embryos and indicate that the mechanism loses its effectiveness when the embryos originate from asynchronous ovulations.
Electrostatically Tunable Coadsorption of Sodium Dodecyl Sulfate and Poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) Triblock Copolymer to Silica

Interfacial properties can be tuned by exploiting polymer/surfactant interactions. We find that coadsorption of the anionic surfactant sodium dodecyl sulfate (SDS) and the amphiphilic triblock copolymer poly(ethylene oxide-b-propylene oxide-b-ethylene oxide), Pluronic F108, to silica is extremely sensitive to SDS concentration and ionic strength. First, using a pyrene solubilization assay we identify the surfactant concentration regimes where different F108/SDS aggregates form in bulk solution at several ionic strengths. We then measure the total surface excess concentration of coadsorbing F108 and SDS using optical reflectometry. Above the critical aggregation concentration where F108/SDS aggregates form, the coadsorbed amount decreases with increasing surfactant concentration until an SDS concentration is reached at which adsorption is prevented entirely. Furthermore, although adsorbed layers containing only F108 are irreversibly adsorbed, F108/SDS layers are reversibly adsorbed. These results suggest t...