cssi/SciSciGPT-SciSciNet huggingface dataset:
Monoids on groups with BN-Pairs

The theory of linear algebraic monoids has been developed in the last few years by L. Renner and the author [21-361 as a generalization of the theory of linear algebraic groups [16,40]. In applications of the theory of linear algebraic groups, one is naturally led to consider groups with BNpairs (or Tits systems) 12, 4, 9, 42,431. This class of groups includes in particular the groups of Lie type, so that the abstract properties of Tits systems are useful in studying the conjugacy classes and representations of groups of Lie type (see [4,9]). Our interest is in monoids. So let M be a monoid such that the group of units G has a BN-pair. In general G has very little to do with the rest of M. In fact, for a given G, M\G could be an arbitrary semigroup. So we introduce three axioms which intimately connect the idempotent structure of M with the structure of G. We then say that M is a monoid on G. The prime example is a connected regular linear algebraic monoid with zero. But there are other natural examples. For instance, Renner [37] is developing a theory of “monoids of Lie type” along the lines of Steinberg [41] for groups. Another example arises from the work of Smith [39] and Cabanes [3]. From their work, one can associate with certain irreducible modular representations, 4 : G + GL( V), a set of idempotents Es End(V). Then the monoid M generated by 4(G) and E is a monoid on 4(G) in the examples we have worked out, and very likely in general. In the situation of linear algebraic monoids, there is a natural type map from the finite lattice % of conjugacy classes of idempotents (g the lattice of f-classes) into the power set of the Dynkin diagram of G. The idea of the type map is due to Lex Renner and is exploited by Renner and the author [31] to show in particular that the system of idempotents can be constructed from the type map. In the present situation of monoids on G, there is again a type map I which characterizes the system of idempotents. 139 0021~8693/89 $3.00
Quantitative assessment of cancer risk from exposure to diesel engine emissions

Quantitative estimates of lung cancer risk from exposure to diesel engine emissions were developed using data from three chronic bioassays with Fischer 344 rats. Human target organ dose was estimated with the aid of a comprehensive dosimetry model. This model accounted for rat-human differences in deposition efficiency, normal particle clearance rates, transport of particles to lung-associated lymph nodes, respiration rates, and lung surface area, as well as high-dose inhibition of particle clearance. Recent evidence indicates that the inert carbon core of the diesel particulate matter is likely to be the primary source of carcinogenicity. The epithelial tissue lining the alveoli and lower airways is the primary target site for induction of lung tumors. Dose was therefore based upon the concentration of carbon particulate matter per unit lung surface area. Unit risk estimates were developed using either a time-to-tumor or a linearized multistage model. The unit risk estimates, defined as the 95% upper confidence limit of the cancer risk from continuous lifetime exposure to 1 microgram/m3 of diesel exhaust particulate matter, varied from 1.0 to 4.6 x 10(5) with a geometric mean of 1.7 x 10(5).
Teachers' perceptions of students' excuses for academic difficulties

Ninety-seven teachers described situations in which their students experienced academic difficulties and gave reasons (excuses) to explain their difficulties. Teachers indicated whether or not they believed the reasons students gave, what they thought the “real” reasons for the students' difficulties were, and how they reacted and behaved toward the students. Analysis of teachers' reports indicated that students were most likely to attribute their academic difficulties to external, uncontrollable factors, whereas teachers tended to believe that the “real” reasons for students' difficulties were internal and controllable. Teachers reported that they would react in a positive manner toward the students whether or not they believed the reasons the students gave to explain their difficulties. Implications of these findings for student motivation are discussed.
Dependence of Gonadotropin-releasing Hormone-induced Neuronal MAPK Signaling on Epidermal Growth Factor Receptor Transactivation

The hypothalamic decapeptide, gonadotropin-releasing hormone (GnRH), utilizes multiple signaling pathways to activate extracellularly regulated mitogen-activated protein kinases (ERK1/2) in normal and immortalized pituitary gonadotrophs and transfected cells expressing the GnRH receptor. In immortalized hypothalamic GnRH neurons (GT1-7 cells), which also express GnRH receptors, GnRH, epidermal growth factor (EGF), and phorbol 12-myristate 13-acetate (PMA) caused marked phosphorylation of ERK1/2. This action of GnRH and PMA, but not that of EGF, was primarily dependent on activation of protein kinase C (PKC), and the ERK1/2 responses to all three agents were abolished by the selective EGF receptor kinase inhibitor, AG1478. Consistent with this, both GnRH and EGF increased tyrosine phosphorylation of the EGF receptor. GnRH and PMA, but not EGF, caused rapid phosphorylation of the proline-rich tyrosine kinase, Pyk2, at Tyr(402). This was reduced by Ca(2+) chelation and inhibition of PKC, but not by AG1478. GnRH stimulation caused translocation of PKC alpha and -epsilon to the cell membrane and enhanced the association of Src with PKC alpha and PKC epsilon, Pyk2, and the EGF receptor. The Src inhibitor, PP2, the C-terminal Src kinase (Csk), and dominant-negative Pyk2 attenuated ERK1/2 activation by GnRH and PMA but not by EGF. These findings indicate that Src and Pyk2 act upstream of the EGF receptor to mediate its transactivation, which is essential for GnRH-induced ERK1/2 phosphorylation in hypothalamic GnRH neurons.
The Validity of Job Knowledge Measures

The validity of written job knowledge tests as predictors of job performance and training success was examined. Based on a sample of 363,528 persons and 502 coefficients, meta-analyses were performed to investigate the extent of validity generalization and the effects of two hypothesized moderator variables: content similarity and job complexity. Corrected mean validities were 0.45 for studies predicting job performance and 0.47 for studies of training success. Support was found for both moderators since validities were higher for high complexity jobs and when job-test content similarity was high. The implications of this study for personnel selection and research in the area of work performance are discussed.
Mechanical behaviour of partially crystallized amorphous alloys

Deformation and fracture of partially crystallized Ni55Pd35P10 amorphous alloys have been investigated. The samples with a few percent crystallization show a fracture stress (175 kg mm−2) and apparent Young's modulus (19.5×103kg mm−2) greater than those completely amorphous or partially crystallized 50%. On the other hand, the fracture strain of the former are lower than those of the two latter. A simulated model with mixtures of carborundum powder with grease, shows accord with morphological and mechanical aspects of the partially crystallized alloys. As expected, microcrystals embedded in an amorphous material act as obstacles to plastic flow.
Beyond Implications and Applications: the Story of ‘Safety by Design’

Using long-term anthropological observations at the Center for Biological and Environmental Nanotechnology in Houston, Texas, the article demonstrates in detail the creation of new objects, new venues and new modes of veridiction which have reoriented the disciplines of materials chemistry and nanotoxicology. Beginning with the confusion surrounding the meaning of ‘implications’ and ‘applications’ the article explores the creation of new venues (CBEN and its offshoot the International Council on Nanotechnology); it then demonstrates how the demands for a responsible, safe or ethical science were translated into new research and experiment in and through these venues. Finally it shows how ‘safety by design’ emerged as a way to go beyond implications and applications, even as it introduced a whole new array of controversies concerning its viability, validity and legitimacy.
Purification and properties of 3′-phosphoadenosine-5′-phosphosulphate: Desulphoglucosinolate sulphotransferase from Brassica juncea cell cultures

Abstract The enzyme 3′-phosphoadenosine-5′-phosphosulfate:desulphoglucosinolate sulphotransferase was partially purified from Brassica juncea cell cultures by fractional precipitation with ammonium sulphate, anion-exchange chromatography and gel filtration. The resulting enzyme preparation had a specific activity of ⋔ ∼ 2 nmol/hr mg protein, representing a 230-fold purification and an overall yield of 58%, compared with crude cell extract. The enzyme had no absolute requirements for cations, and was inhibited by various SH-group reagents. The enzyme was stable up to 40° for at least 1 hr. Maximum activity was exhibited between pH 8.5 and 9.0 at 30°. The enzyme had an apparent pI and M r of 4.84 and 44 000, respectively. The K r values for desulphobenzylglucosinolate (DSBG) and 3′-phosphoadenosine-5′-phosphosulphate (PAPS) were 2.3 and 0.78 μM, respectively. The enzyme did not sulphate DSBG in the presence of adenosine-5′-phosphosulphate. Product inhibition studies established that 3′-phosphoadenosine-5′-phosphate was competitive with PAPS ( K i 0.4 μM).
Gain changes of the cat's vestibulo-ocular reflex after flocculus deactivation

Motor learning can be demonstrated in the vestibulo-ocular reflex (VOR) by changing its gain (eye velocity/head velocity) with goggles and optokinetic (OK) drums. It is known that the flocculus is essential for this plasticity but there is controversy about whether the modifiable synapses mainly responsible are in the flocculus. To investigate this further we utilized the known reciprocal relationship between complex spikes and simple spikes in Purkinje cell discharges. By stimulating climbing fibers from the olive to the flocculus at 7 Hz, the simple spike rate of almost all recorded floccular cells could be driven to zero. This was termed floccular shutdown and is felt to effect a functional, reversible flocculectomy. Sixty single units in the flocculi of four cats were recorded. Stimulation of the climbing fibers at 7 Hz caused the discharge rate to decrease to zero in 95% of these cells. The gain of the horizontal VOR in three cats was driven repeatedly to twice or half its normal value by rotation within a moving OK drum and also by wearing magnifying or fixed-field goggles; this process required 3 days. If, on the 4th day, the cat was exposed to an OK drum rotating in the opposite direction, the gain was driven back to normal in 30 min. If, however, the climbing fibers were stimulated at 7 Hz during these 30 min, the gain did not return — learning was blocked. This verified that loss of floccular activity by this method abolishes VOR gain plasticity. Moreover, when 7 Hz stimulation first began, after 3 days of adaptation, the adapted gain remained at its adapted value, either half or twice normal, even in the face of floccular shutdown. This result appears incompatible with the hypothesis that the modifiable synapses are in the flocculus.
Spectroscopic study of laser-produced plasmas in hydrogen.

A 300-mJ, 7-ns, 1064-nm pulse from a Q-switched neodymium-doped yttrium aluminum garnet laser was tightly focused into ${\mathrm{H}}_{2}$ at pressures of the order of 1 atm or less. Charge-coupled-device images, time-resolved schlieren, and time-resolved spectra from the vacuum ultraviolet through the visible distinguish the prompt centrally localized emission during the initial breakdown from the subsequent blast wave and shock dissociation of the gas. Schlieren images show that the shock wave expands from the center with a velocity in excess of 13 km/s, and then slows to close to sound wave speed within 1.5 \ensuremath{\mu}s. Inside the shock front, starting with an initial electron density greater than 4\ifmmode\times\else\texttimes\fi{}${10}^{18}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}3}$ and a temperature of ${10}^{5}$ K, the emitting atomic gas cools and leaves a low-density core surrounded by a cylindrical shell of slowly expanding excited H about 1.5 mm from the focal axis after 8 \ensuremath{\mu}s. The regions responsible for visible and vacuum ultraviolet emission are in local thermodynamic equilibrium. The density, temperature, and flow agree quantitatively with the predictions of Saha ionization and excitation equilibrium in a cylindrical blast wave with counterpressure. These models characterize the postplasma gas close to the region of breakdown and permit the source to be used for quantitative spectroscopic studies of atomic and molecular processes.
Photorefractive keratectomy in the cat eye: Biological and optical outcomes

Purpose To quantify optical and biomechanical properties of the feline cornea before and after photorefractive keratectomy (PRK) and assess the relative contribution of different biological factors to refractive outcome. Setting Department of Ophthalmology, University of Rochester, Rochester, New York, USA. Methods Adult cats had 6.0 diopter (D) myopic or 4.0 D hyperopic PRK over 6.0 or 8.0 mm optical zones (OZ). Preoperative and postoperative wavefront aberrations were measured, as were intraocular pressure (IOP), corneal hysteresis, the corneal resistance factor, axial length, corneal thickness, and radii of curvature. Finally, postmortem immunohistochemistry for vimentin and α-smooth muscle actin was performed. Results Photorefractive keratectomy changed ocular defocus, increased higher-order aberrations, and induced myofibroblast differentiation in cats. However, the intended defocus corrections were only achieved with 8.0 mm OZs. Long-term flattening of the epithelial and stromal surfaces was noted after myopic, but not after hyperopic, PRK. The IOP was unaltered by PRK; however, corneal hysteresis and the corneal resistance factor decreased. Over the ensuing 6 months, ocular aberrations and the IOP remained stable, while central corneal thickness, corneal hysteresis, and the corneal resistance factor increased toward normal levels. Conclusions Cat corneas exhibited optical, histological, and biomechanical reactions to PRK that resembled those previously described in humans, especially when the OZ size was normalized to the total corneal area. However, cats exhibited significant stromal regeneration, causing a return to preoperative corneal thickness, corneal hysteresis and the corneal resistance factor without significant regression of optical changes induced by the surgery. Thus, the principal effects of laser refractive surgery on ocular wavefront aberrations can be achieved despite clear interspecies differences in corneal biology.
Lived Body and Environment

Merleau-Ponty developed a phenomenology of the body that promoted a non-dualistic account of human existence. In this paper I intend to develop Merleau-Ponty's analysis further by questioning his account of the body on the issues of body perception, and the body's relation to its environment. To clarify these issues I draw from both the phenomenological tradition and recent psychological investigations.
Occipital neuralgia secondary to CerebroSpinal fluid leak.

Spontaneous CSF leakage is now recognized as a secondary chronic daily headache (CDH) and its characteristic feature is a postural (orthostatic) headache. Despite occipital headaches being common, only one published case report exists of occipital neuralgia associated with significant cerebral descent from CSF leakage. Our case is the first one, occurring without prominent cerebral descent. Potential pathogenic mechanisms are discussed.
The effect of policy and background variables on total factor productivity for public transit

This paper investigates total factor productivity as a unified measure of transit performance. The approach uses the shift in the cost function of inputs and outputs as the measure of change in productivity. A three step regression procedure was used to estimate model parameters. The approach was applied to a sample of transit agencies. Predictor variables were tested for a two-year period representing different financial and background situations. Hypotheses were tested for static and dynamic measures of environment and policy with capacity and efficiency and for measures of capacity and efficiency with productivity. It was found that when vehicle-miles was the output measure, only vehicle efficiency was related to labor productivity. Further, it was found that when passenger-miles was the output variable, only population and fleet size were good predictors of total factor productivity. Productivity is, in general, stable and approximately constant for these agencies. The implication for transit agencies is to concentrate efforts to improve productivity on highly congested corridors and, overall, through the use of vehicle and manpower scheduling.
Energy-linked reactions in photosynthetic bacteria: Pi ⇋ HOH oxygen exchange catalyzed by the membrane-bound inorganic pyrophosphatase of Rhodospirillum rubrum

Abstract The inorganic phosphate-water oxygen exchange reaction has been studied in chromatophores of Rhodospirillum rubrum . Under appropriate conditions, chromatophores catalyzed this exchange at a rate of up to 150 μatom oxygen/h/mg bacteriochlorophyll. The reaction is largely inhibited by inhibitors of the membrane-bound inorganic pyrophosphatase, fluoride and methylene diphosphonate, and is not inhibited by oligomycin. These results indicate that the P i ⇋ HOH oxygen exchange is almost entirely due to the pyrophosphatase. In the presence of ADP, the exchange reaction was stimulated by about 40% and this portion of the exchange was sensitive to oligomycin, but not to fluoride or methylene diphosphonate. Thus this portion of the exchange can be attributed to the ATP synthese complex. The rates of the oxygen exchange reaction and other chromatophore-catyalyzed reactions are compared.
Effect of Egg Age, Storage Temperature, and Storage Duration on Egg Hatch of Diabrotica undecimpunctata howardi (Coleoptera: Chrysomelidae)

The effect of egg age and storage temperature and duration on the percentage of hatch and time to 50% hatch for eggs of Diabrotica undecimpunctata howardi Barber, southern corn rootworm, was determined by exposing 1-, 3-, and 5-d-old eggs at 6 temperatures from 0 to 15°C for durations of 1-6 wk. Egg age, storage temperature, storage duration, and their interactions had a significant influence on percentage of egg hatch and time to 50% hatch. Regression models were developed to allow prediction of percentage of hatch and time to 50% hatch. Eighteen treatment combinations maintained egg viability >94%. Percentage of hatch and time to 50% hatch were optimized with 1-d-old eggs incubated at 15°C for 3 wk.
Hyposmotically induced amino acid release from the rat cerebral cortex: role of phospholipases and protein kinases.

Abstract In an evaluation of the contribution of swelling-induced amino acid release, through the regulatory volume decrease (RVD) process, to cerebral ischemic injury, studies of the role of phospholipases and protein kinases in the response to hyposmotic stress were undertaken using an in vivo rat cortical cup model. Hyposmotic stress induced significant releases of aspartate, glutamate, glycine, phosphoethanolamine, taurine and GABA from the rat cerebral cortex. Taurine release was most affected, exhibiting a greater than 9-fold increase during the hyposmotic stimulus. The phospholipase A2 (PLA2) inhibitors 4-bromophenacyl bromide (1 μM) and 7,7-dimethyleicosadienoic acid (5 μM) had no significant effects on hyposmotically induced amino acid release. AACOCF3 (50 μM), an inhibitor of cytosolic PLA2 decreased taurine release to 84% of DMSO controls. The release of the other amino acids was not affected. The phospholipase C inhibitor U73122 (5 μM) had no significant effects on amino acid release. The protein kinase C (PKC) inhibitor chelerythrine (5 μM) significantly reduced hyposmotically induced taurine release to 72% of saline controls but had no significant effects on the other amino acids. Stimulation of PKC with phorbol 12-myristate, 13-acetate (10 μM) did not significantly change taurine, glutamate, glycine or phosphethanolamine release. The releases of aspartate and GABA were enhanced 2 to 3 fold. Phorbol 12,13-didecanoate (10 μM), another potent stimulator of PKC, significantly increased taurine release to 122% of DMSO controls. The releases of aspartate, glutamate and glycine were enhanced 2.5 to 3.5 fold. Similarly, stimulation of protein kinase A with forskolin (100 μM) significantly increased taurine, aspartate, and glycine release 1.5- to 2-fold compared to DMSO controls. In summary, phospholipases may play a minor role in volume regulation. These studies also support the hypothesis that protein kinases play a modulatory role in the RVD response. The results show that although RVD may play a role, additional mechanisms, including phospholipase activation, must be involved in the ischemia-evoked release of excitotoxic amino acids.
Exercise Coaching and Rehabilitation Counseling Improve Quality of Life for Predialysis and Dialysis Patients

Advances in medical treatment have improved the rehabilitation potential of predialysis (P) and dialysis (D) patients, but deficits remain in their physical and vocational functioning. We studied 18 P
Altered glycosaminoglycan composition of rat forelimb-buds during hydroxyurea teratogenesis: an indication of repair.

We report here the effect of hydroxyurea (HU), which is an inhibitor of DNA synsthesis and a known cytotoxic and teratogenic agent, on the composition of glycosaminoglycans (GAGs) in the extracellular matrix of the developing forelimb of the rat. HU injected on day 12 has been shown to produce one missing digit and multiple missing digits on day 13 (Ritter et al., '73). Pregnant Wistar rats were treated (IP) with 1,000 mg/kg HU on either day 12 or day 13 (9:00 a.m.) of gestation and sacrificed 0–96 hours later. Forelimbs were dissected and pooled by litter. GAGs were extracted and then separated by microzone electrophoresis on cellulose acetate membranes. Identification of GAG was confirmed by digestion with specific polysaccharidases. Such analysis of control forelimb-buds revealed hyaluronic acid decreasing from 62% of total GAG at day 12 to 36% total GAG at day 16, whereas chondroitin sulfate increased from 34% to 58%. HA content of forelimb-buds treated on day 12 was 22% greater than controls at 12 hours posttreatment, 45.5% at 24 hours posttreatment, returning to control levels at 60 hours after treatment. Chondroitin sulfate (CS) level decreased by 20% at 48 hours after treatment, returning to control level by 72 hours. Hyaluronate levels of HU 13 treated forelimb-buds were 46% greater than controls at 24 hours after HU treatment, returning to control levels at 36 hours. CS levels were significantly lower than controls at 36 hours posttreatment. Histochemical analysis was performed to localize these alterations in GAG composition within the forelimbs. Beginning 12 hours posttreatment and continuing until 48 hours, an increase in HA content was observed in the mesenchymal compartment of the forelimb (1) beneath the apical ectodermal ridge and (2) between the ectoderm and prechondrogenic blastema (peripheral zone). This HA increase may be interpreted as a recovery (repair) phase of the pathogenesis of the HU malformation. To confirm that this shift in GAG is indicative of a compensatory phenomenon mitotic indices of the forelimbs were examined. At 36 hours posttreatment substantial increase in mitotic activity was observed in the subridge and peripheral regions of forelimbs treated on day 12, whereas those treated on day 13 demonstrated a significant increase only in the subridge zone. The increase in HA composition in the zones of the forelimb correlated well with the increase of mitotic activity. It is suggested that elevated HA/CS ratio allowed for increased proliferation and reorganization of the mesenchymal cell population, whereas the return to control levels marked the cessation of repair and resumption of differentiation.
THE t-J AND FRUSTRATED HEISENBERG MODELS: A STATUS REPORT ON NUMERICAL STUDIES

Recent numerical work on the t-J model and the frustrated spin- Heisenberg antiferromagnet is reviewed. Lanczos results are mainly discussed but other methods are also mentioned. Static and dynamical properties of one and more holes in the t-J model are presented. The current active search for nontrivial ground states of the frustrated Heisenberg model is summarized. It is concluded that numerical methods are providing useful information in the study of these models.
Thin-layer chromatographic separation of cystine and the N-ethylmaleimide adducts of cysteine and glutathione

Abstract Interest in cystine metabolism related to human cystinuria and cystinosis has lead to increased investigation of cysteine and glutathione formation from cystine by various tissues (1, 2). Advantage has been taken of the extremely rapid and quantitative reaction reported initially by Friedmann et al. (3) and investigated further by others (4–6) in which cysteine and reduced glutathione combine with N -ethylmaleimide (NEM) to form the stable adducts S ( N -ethylsuccinimido) cysteine (cysteine-NEM) and S ( N -ethylsuccinimido) glutathione (glutathione-NEM), respectively. The use of radioactive substrates has proved to be an extremely sensitive method for detection of these compounds in metabolic studies (1, 7). Presently, however, S ( N -ethylsuccinimido) cysteine, S ( N -ethylsuccinimido) glutathione, and cystine are separated by lengthy paper chromatography (8–10), by combined ion-exchange chromatography with flow counting through an anthracene-packed cell in a liquid scintillation counter (11), or by high-voltage electrophoresis (12). This communication describes the quick, efficient separation of cysteine-NEM by thin-layer chromatography on silica gel or MN300 cellulose sheets and the usefulness of N -ethylmaleimide-1- 14 C and 35 S- l -cystine in conjunction with thin-layer chromatography to study the formation of these adducts in metabolic systems.
The Production and Thermal Stability of a Refined Dispersion of Er2O3 in Ti3Al using Rapid Solidification Processing

The use of rapid solidification processing to produce a refined dispersion of second phase in Ti3Al is demonstrated. Laser surface melting produces a disordered solid solution of Ti and Al with a supersaturation of Er and 0. A refined dispersion of Er2O3 is formed on heat treatment at 973 K. This oxide is found to be stable at elevated temperatures up to 1173 K.
Determination of Trace Atrazine Levels in Water by a Sensitive Magnetic Particle-Based Enzyme Immunoassay

Atrazine is a pre- and post-emergence selective herbicide specific for broad-leaved weeds and grasses. Although extensively applied in the United States, its use in Europe is limited and restricted. European drinking water regulations are strict: allowable atrazine contamination levels are 100 parts per trillion (ppt, ng/L). As a result of European regulations, increased method sensitivity is needed to detect atrazine-contaminated water supplies. A sensitive and rapid enzyme immunoassay using specific atrazine antiserum covalently coupled to a magnetic particle solid phase has been developed for the quantitation of atrazine in water at parts per trillion levels. The immunoassay provides accurate detection to as low as 15 ppt of atrazine directly from a 250 μL water sample. Recovery from water samples without sample pretreatment averaged 100% and compared favorably to samples with GC/MS results (r = 0.993). The immunoassay represents a valuable method to detect trace amounts of atrazine in ground, surface...
Incorporating Monte Carlo Simulation into Physiologically Based Pharmacokinetic Models Using Advanced Continuous Simulation Language (ACSL): A Computational Method

Biologically based models with physiological parameters are becoming more popular as a tool to estimate target tissue doses from chemical exposures. However, the majority of current physiologically based pharmacokinetic (PBPK) models do not take into account the uncertainty and/or variability within the various model parameters. Consideration of uncertainty is important to evaluate the predictive ability and complexity of a model as well as identification of parameters which contribute disproportionately to variability in model output. In order to estimate the uncertainty in PBPK model output, a versatile and simple computational method is presented which can be readily incorporated into the majority of PBPK models without extensive additions to model computer code. In this paper, a separate computer program for Monte Carlo simulation is furnished that randomly samples values for model parameters and writes them into a run-time language (command file) format which can then be utilized to execute individual PBPK models. Modifications to the PBPK model allow the desired output to be written to a data file for statistical analysis. The method presented in this paper is applied to a simple PBPK model for benzene disposition.
PET imaging of tumor angiogenesis in mice with VEGF-A targeted 86Y-CHX-A″-DTPA-bevacizumab

Bevacizumab is a humanized monoclonal antibody that binds to tumor-secreted vascular endothelial growth factor (VEGF)-A and inhibits tumor angiogenesis. In 2004, the antibody was approved by the US Food and Drug Administration (FDA) for the treatment of metastatic colorectal carcinoma in combination with chemotherapy. This report describes the preclinical evaluation of a radioimmunoconjugate, (86)Y-CHX-A″-DTPA-bevacizumab, for potential use in Positron Emission Tomography (PET) imaging of VEGF-A tumor angiogenesis and as a surrogate marker for (90)Y-based radioimmunotherapy. Bevacizumab was conjugated to CHX-A″-DTPA and radiolabeled with (86)Y. In vivo biodistribution and PET imaging studies were performed on mice bearing VEGF-A-secreting human colorectal (LS-174T), human ovarian (SKOV-3) and VEGF-A-negative human mesothelioma (MSTO-211H) xenografts. Biodistribution and PET imaging studies demonstrated highly specific tumor uptake of the radioimmunoconjugate. In mice bearing VEGF-A-secreting LS-174T, SKOV-3 and VEGF-A-negative MSTO-211H tumors, the tumor uptake at 3 days postinjection was 13.6 ± 1.5, 17.4 ± 1.7 and 6.8 ± 0.7 % ID/g, respectively. The corresponding tumor uptake in mice coinjected with 0.05 mg cold bevacizumab were 5.8 ± 1.3, 8.9 ± 1.9 and 7.4 ± 1.0 % ID/g, respectively at the same time point, demonstrating specific blockage of the target in VEGF-A-secreting tumors. The LS-174T and SKOV3 tumors were clearly visualized by PET imaging after injecting 1.8-2.0 MBq (86)Y-CHX-A″-DTPA-bevacizumab. Organ uptake quantified by PET closely correlated (r(2) = 0.87, p = 0.64, n = 18) to values determined by biodistribution studies. This preclinical study demonstrates the potential of the radioimmunoconjugate, (86)Y-CHX-A″-DTPA-bevacizumab, for noninvasive assessment of the VEGF-A tumor angiogenesis status and as a surrogate marker for (90)Y-CHX-A″-DTPA-bevacizumab radioimmunotherapy.
Magnetic anisotropy of substituted R 2 Co 17 compounds (R = Nd, Sm, Er and Yb)

Saturation magnetization (M s ), Curie temperature (T c ) and easy direction of magnetization have been measured on Yb 2 Co 17-x Fe x , Er 2 Co 17-x M x (M = Fe, Mn, Ni), Nd 2 Co 17-x Al x and Sm 2 Co 17-x Al x compounds. The T c and M s vary in a similar manner for all the compounds investigated. Anisotropy field variation also shows a similar trend. It is proposed that the observed variations can be used as a guide for future experiments on the substituted R 2 Co 17 compounds.
A comparison of obtaining field data using electronic and written methods

The use of electronic measurement and recording devices was investigated during the Alaska Department of Fish and Game 2002 red king crab (Paralithodes camtschaticus) stock assessment survey in Southeast Alaska. Because of the importance of survey data to fishery management, these data were also collected by written methods, allowing direct comparison of the two methods. Including data collection and transferring to computer format, electronic sampling was about three times faster than written methods. Additionally, when electronic methods were used, the sampling time, in person seconds, was about half that needed for written methods, potentially increasing the sample size for the survey. The few discernable differences between data collected by the two methods were primarily attributable to intersampler variability. Even with a prototype data collection system that was cumbersome to use, large savings in time and money could be realized with little effect on data collected. The limitations of the system used could easily be overcome with different equipment and careful attention to programming, further increasing data collection efficiency and accuracy.
Degradation of a low-carbon steel in long operation in an oil-hydraulic unit

We present an atypical example of corrosion fracture of a low-strength high-plasticity steel from an internal surface formed by a hole in a choke of an oil-hydraulic unit, operated for 35 years. The conclusion that, in terms of the effect on the mechanical behavior of the metal operated for a long time, oil can be considered to be an aggressive medium is made. Its influence is enhanced by the preliminary plastic deformation of subsurface layers of the metal using force drilling of the hole in the choke. We detected fractographically the subcritical growth of a crack from the internal surface of the choke with multiple secondary cracking, which is interpreted as a manifestation of the mechanism of hydrogen embrittlement of the metal degraded during long operation.
Adenovirus-mediated Hepatocyte Growth Factor Expression in Mouse Islets Improves Pancreatic Islet Transplant Performance and Reduces Beta Cell Death *

Hepatocyte growth factor (HGF) increases beta cell proliferation and function in rat insulin promoter (RIP)-targeted transgenic mice. RIP-HGF mouse islets also function superiorly to normal islets in a transplant setting. Here, we aimed to determine whether viral gene transfer of the HGF gene into mouse islets ex vivo could enhance the performance of normal islets in a streptozotocin-diabetic severe combined immunodeficient mouse marginal islet mass model in which 300 uninfected or adenovirus (Adv) LacZ-transduced islet equivalents were insufficient to correct hyperglycemia. In dramatic contrast, 300 AdvHGF-transduced islet equivalents promptly (day 1) and significantly (p
SU-E-T-92: The Field Size Dependence of the ArcCheck 4D Diode Array and Its Correction Strategy

Purpose: The ArcCheck 4D diode array was designed specifically for rotational therapy QA and records data every 50 milliseconds. This work quantifies its field size dependence and designs strategy for its correction. Methods: The field size dependence was measured using a 6 MV photon beam of a linac and compared with ion chamber measurements in the same geometry. Square field sizes of 4×4 cm2 to 30×30 cm2 as well as rectangular fields of 6×4 to 6×30 cm2 elongated in both the X and Y directions were measured. To correct for the field size dependence, the field size for each signal update was automatically detected and a correction factor that corresponded to the equivalent square was applied to the raw data. Five fixed‐gantry IMRT plans (18 fields) that covered a variety of sites were used to test the correction strategy. Treatment plans were generated using the Pinnacle3 (v9.0) with a density override of 1.05 g/cc for the entire cylinder. Only beams that did not go through the treatment couch were used for the comparison to eliminate the uncertainty associated with couch transmission. Results: Normalized to a field size of 10×10 cm2, the diodes over responded by 2.1% at 30×30 cm2 and under responded by 2.0% at 4×4 cm2. The biggest improvement in passing rates was seen in the head and neck plan which exhibited the largest treatment fields, with the average passing rates improved from 79.5% and 90.4% for 2%/2mm and 3%/3mm, respectively, when no field size dependence was corrected, to 95.7% and 98.7%, respectively, with field size dependence correction. Conclusions: The ArcCheck diodes exhibit a measurable field size dependence which can be corrected using its 4D raw data. This correction is important for large and small treatment fields which allows for the use of more stringent criteria.
A cellular automation model of excitable media: IV. untwisted scroll rings

Abstract We study the motion of untwisted circular scroll rings in an excitable medium modeled by a cellular automation that includes the effects of curvature and dispersion on wave propagation. We find that scroll rings either shrink or expand, with a velocity that is a function of the curvature of the ring, and they drift along their axis of symmetry.
Prolonging the female reproductive lifespan and improving egg quality with dietary omega‐3 fatty acids

Women approaching advanced maternal age have extremely poor outcomes with both natural and assisted fertility. Moreover, the incidence of chromosomal abnormalities and birth defects increases with age. As of yet, there is no effective and practical strategy for delaying ovarian aging or improving oocyte quality. We demonstrate that the lifelong consumption of a diet rich in omega-3 fatty acids prolongs murine reproductive function into advanced maternal age, while a diet rich in omega-6 fatty acids is associated with very poor reproductive success at advanced maternal age. Furthermore, even short-term dietary treatment with a diet rich in omega-3 fatty acids initiated at the time of the normal age-related rapid decline in murine reproductive function is associated with improved oocyte quality, while short-term dietary treatment with omega-6 fatty acids results in very poor oocyte quality. Thus, omega-3 fatty acids may provide an effective and practical avenue for delaying ovarian aging and improving oocyte quality at advanced maternal age.
Geology of the Carnegie museum dinosaur quarry site of Diplodocus carnegii, Sheep Creek, Wyoming

Abstract The holotype of Diplodocus carnegii Hatcher, 1901, consists of a partial skeleton (CM 84) that was recovered, along with a second partial skeleton of the same species (CM 94), from the upper 10 m of the Talking Rock facies of the Brushy Basin Member of the Morrison Formation exposed along Bone Quarry Draw, a tributary of Sheep Creek in Albany County, Wyoming. A composite measured section of the stratigraphic interval exposed adjacent to the quarry indicates that the Brushy Basin Member in this area is a stacked succession of lithofacies consisting of hackly, greenish gray, calcareous mudstone and greenish brown, dense, fine-grained limestone. The more erosion resistant limestone layers can be traced over many hundreds of meters. Thus, these strata do not appear to represent a highly localized deposit such as a stream channel, oxbow lake, or backwater pond. The Sheep Creek succession is interpreted as representing a clastic-dominated lake where high turbidity and sediment influx produced depositio...
Reliability of a repairable standby system with imperfect sensing and switching

A reliability model for a repairable standby system with imperfect sensing and switching units is developed. The system has two unequal units which have energized as well as quiescent failure rates and have corresponding repair rates. The system has a sensing unit with a nonzero failure rate and a switching unit which has both cyclic and continuous failure rates, with the continuous mode including failing-open and failing-closed function modes. The system's reliability is obtained in an explicit form. Numerical examples are given, and the effects of the sensing and switching unit's failure rates on the system's reliability are discussed. >
Climatic variability and episodic Pinus ponderosa establishment along the forest-grassland ecotones of Colorado

The primary objective of this study was the detection of possible climatic influences on the recent (i.e., past c. 40 years) establishment of ponderosa pine (Pinus ponderosa) at or near forest-grassland ecotones in the northern Front Range of Colorado. Germination dates were precisely determined for >500 juvenile ponderosa pine collected in six widely dispersed sample areas. All sites sampled were open areas lacking an overstory tree cover but located near seed sources. To evaluate the effects of recent climatic variation on recruitment and survival patterns, three types of climate data were used: (1) instrumental climate records from nearby local weather stations; (2) a multivariate index of El Nino/Southern Oscillation (ENSO); and (3) a regional, ponderosa pine tree-ring index sensitive to moisture variation. There is a strong association between episodic recruitment of ponderosa pine and years in which spring and fall moisture availability is high in the instrumental climate record. During the past 40 years, tree establishment was highly episodic and concentrated mainly in four years—1973, 1979, 1983, and 1990. These years are also associated with large-scale warming of sea-surface temperatures in the eastern tropical Pacific (i.e., El Nino events). These years of abundant seedling establishment also coincide with years of above average radial growth in mature ponderosa pine. Thus, at open sites suitable for the survival of shade-intolerant ponderosa pine, successful establishment of seedlings is highly episodic depending on local moisture availability related to broad-scale climatic variation. This study demonstrates the climatic sensitivity of ponderosa pine recruitment at low elevation sites along forest-grassland ecotones in the northern Colorado Front Range. # 2006 Elsevier B.V. All rights reserved.
Electroweak gauge boson production at hadron colliders through O(α s 2 )

We describe a calculation of the O({alpha}{sub s}{sup 2}) QCD corrections to the fully differential cross section for W and Z boson production in hadronic collisions. The result is fully realistic in that it includes spin correlations, finite width effects, {gamma}-Z interference and allows for the application of arbitrary cuts on the leptonic decay products of the W and Z. We have implemented this calculation into a numerical program. We demonstrate the use of this code by presenting phenomenological results for several future LHC analyses and recent Tevatron measurements, including the W cross section in the forward rapidity region and the central over forward cross section ratio.
Special considerations for carvedilol use in heart failure

Abstract Remarkable improvements in morbidity and mortality caused by heart failure have been realized because of a greater understanding of the pathobiologic mechanisms of left ventricular dysfunction and the subsequent application of neurohormonal antagonism to the heart failure milieu. The median survival of patients with chronic heart failure has greatly increased with the use of effective medical therapy that includes angiotensin-converting enzyme inhibitors and β-blockers, especially carvedilol. Still to be addressed is the issue of clinical trials that underrepresent special populations of patients who are affected with heart failure (eg, the elderly, women, and African Americans). Even though heart failure may be a somewhat different illness in etiology, epidemiology, or responsiveness to medical therapy for each of these groups, it is of utmost importance that patients affected by heart failure be treated with agents that have been shown to be of benefit in the major controlled clinical trials in heart failure.
Biological Evaluation of Protein Quality of Radiation-Pasteurized Haddock, Flounder and Crab

SUMMARY— The effects of radiation sub-sterilization or heat-treatment on the protein quality of haddock, crab and flounder were evaluated by determining the protein efficiency ratio (PER). The PER value of haddock radiated at either level was statistically equal to that of non-radiated haddock. The PER value of crab radiated at either level was statistically equal to non-radiated crab in one replication and significantly higher than non-radiated crab in another replication. The PER value of flounder radiated at the low level was significantly less than that of non-radiated flounder, whereas the PER value of flounder radiated at the high level was statistically equal to that of non-radiated flounder. Low PER values were obtained for heat-treated marine products and these values were significantly lower than those for all other marine product treatments investigated. The protein quality of haddock, crab and flounder was not significantly changed as a result of radiation pasteurization.
Dimer formation by a “monomeric” protein

Dimeric proteins can arise by the swapping of structural domains between monomers. The prevalence of this occurrence is unknown. Ribonuclease A (RNase A) is assumed to be a monomer near physiological conditions. Here, this hypothesis is tested and found to be imprecise. The two histidine residues (His12 and His119) in the active site of RNase A arise from two domains (S-peptide and S-protein) of the protein. The H12A and H119A variants have 10(5)-fold less ribonucleolytic activity than does the wild-type enzyme. Incubating a 1:1 mixture of the H12A and H119A variants at pH 6.5 and 65 degrees C results in a 10(3)-fold increase in ribonucleolytic activity. A large quantity of active dimer can be produced by lyophilizing a 1:1 mixture of the H12A and H119A variants from acetic acid. At pH 6.5 and 65 degrees C, the ribonucleolytic activity of this dimer converges to that of the dimer formed by simply incubating the monomers, as expected for a monomer-dimer equilibrium. The equilibrium dissociation constant for the dimer is near 2 mM at both 65 and 37 degrees C. This value of Kd is only 20-fold greater than the concentration of RNase A in the cow pancreas, suggesting that RNase A dimers exist in vivo. The intrinsic ability of RNase A to form dimers under physiological conditions is consistent with a detailed model for the evolution of homodimeric proteins. Dimers of "monomeric" proteins could be more prevalent than is usually appreciated.
Reply to comment by F. A. Dahlen and G. Nolet on 'On sensitivity kernels for 'wave-equation' transmission tomography'

SUMMARY We thank Dahlen & Nolet for the comments (DN05) on our paper (HH05). There are many points of agreement, as we think is clear from HH05, but we respectfully continue to differ in opinion on some fundamental aspects of the finite frequency sensitivity kernels known as ‘banana doughnut’ kernels—hereinafter BDKs, as per the original nomenclature of Dahlen et al.—and their benefit to global tomography. In contrast to DN05’s summary statement, HH05’s main concern about BDKs is not the effect of uncertainty in the earthquake source signature or origin time. HH05 argue that (i) the evaluation of sensitivity kernels in simple media has limitations for the interpretation of broad-band signals by means of (linearized) finite frequency tomography; (ii) finite frequency kernels are (indeed) oscillatory, but in general heterogeneity their structure will be complex and different from BD features; (iii) the resolved length scales of model variations are induced by the spectral scales present in the data, which makes the notion of ‘hole’ irrelevant; and (iv) with the need for ‘damping’ (regularization) and without a basis that matches properly the multi-scale aspects of finite frequency sensitivity, ray theory or finite frequency theory inversions are likely to yield results that are practically the same.
Identification of three flavan-3-ols from grapes

Abstract Three phenolic substances present in sizable amount in grapes, particularly in underripe grape seeds, are relatively easily extracted into ether and were isolated and unequivocally identifed as (+)-catechin, (+)-(2R:3S)-5,7,3′,4′-tetrahydroxyflavan-3-ol; (−)-epicatechin, (−)-(2R:3R)-5,7,3′,4′-tetrahydroxyflavan-3-ol; and (−)-epicatechin-3-gallate. These identifications clear up previous conflicting and incomplete reports and show that the grapevine synthesizes the catechin isomers to be expected from work with other plants.