cssi/SciSciGPT-SciSciNet huggingface dataset:
Elevated intranuclear dihydrotestosterone in prostatic hyperplasia of aging dogs

Abstract 5α-Dihydrotestosterone (DHT) content is several fold higher than normal in whole tissue in hyperplastic prostate of aging men and dogs. The postulate was tested that selective nuclear accumulation of either DHT or 3α-androstanediol (3α-diol) might contribute to the development of benign prostatic hyperplasia (BPH) of aging dogs. The nuclear, mitochondrial, microsomal and cytosolic fractions of both normal ( n = 12) and hyperplastic ( n = 6) prostate were isolated by differential centrifugation and the content of DHT and 3α-diol were measured in each fraction by specific radioimmunoassays. DHT levels were elevated significantly in the nuclei (Wilcoxon rank sum test; 2.4 ± 1.3 ng/g wet weight tissue, mean ± SD, P P P P P P P P P P
A Critical Role for IκB Kinase β in Metallothionein-1 Expression and Protection against Arsenic Toxicity

Arsenic is a widespread environmental toxic agent that has been shown to cause diverse tissue and cell damage and at the same time to be an effective anti-cancer therapeutic agent. The objective of this study is to explore the signaling mechanisms involved in arsenic toxicity. We show that the IκB kinase β (IKKβ) plays a crucial role in protecting cells from arsenic toxicity. Ikkβ-/- mouse 3T3 fibroblasts have decreased expression of antioxidant genes, such as metallothionein 1 (Mt1). In contrast to wild type and IKKβ-reconstituted Ikkβ-/- cells, IKKβ-null cells display a marked increase in arsenic-induced reactive oxygen species (ROS) accumulation, which leads to activation of the MKK4-c-Jun NH2-terminal kinase (JNK) pathway, c-Jun phosphorylation, and apoptosis. Pretreatment with the antioxidant N-acetylcysteine (NAC) and expression of MT1 in the Ikkβ-/- cells prevented JNK activation; moreover, NAC pretreatment, MT1 expression, MKK4 ablation, and JNK inhibition all protected cells from death induced by arsenic. Our data show that two signaling pathways appear to be important for modulating arsenic toxicity. First, the IKK-NF-κB pathway is crucial for maintaining cellular metallothionein-1 levels to counteract ROS accumulation, and second, when this pathway fails, excessive ROS leads to activation of the MKK4-JNK pathway, resulting in apoptosis.
Esophageal perforation: Emphasis on management

Background. Perforation of the esophagus is a deadly injury that requires expert management for survival. Methods. We performed a retrospective clinical review of 66 patients treated at Emory University affiliated hospitals for esophageal perforation between 1973 and 1993. Results. Iatrogenic perforations accounted for 48 injuries (73%), barogenic perforations occurred in 12 patients (17%), trauma was causative in 3 (5%), and 3 patients had esophageal infection and other causes. Lower-third injuries occurred in 43 cases (65%), middle third in 14 (21%), and upper third in 9 (14%). Early contained perforations were managed successfully by limiting oral intake and giving parenteral antibiotics in 12 patients. Cervical perforations were drained without attempt at closer of the leak. Perforations with mediastinal or pleural conlamination recognized early were managed by primary closure and drainage in 28 patients. Reinforcement of the primary closure using stomach fundus, pleural, diaphgramatic, or pericadial flap was performed in 16 patients. Those perforations that escaped ealy recognition required thoughtful management, using generous debridement and drainage and sometimes esophageal resection. The esophageal T tube provided control of leaks in 3 of these patients and was a useful adjunct. Using these management principles, we achieved a 76% survival rate for all patients. Six patients with perforations complicating endoesophageal management of esophageal varices were a high-risk subset with an 83% mortality rate. Conclusions. Esophageal perforation remains an important thoracic emergency. Aggressive operative therapy remains the mainstay for treatment; however, conservative management may be preferred for contained perforations and the esophageal T tube may be used for late perforations.
THE OXYGEN CONSUMPTION OF RABBIT RED CELLS DURING LYSIS, WITH SOME OBSERVATIONS ON THE OXYGEN CONSUMPTION OF PLASMA

1. When rabbit erythrocytes suspended in saline are haemolysed the resulting consumption cannot be predicted with certainty. The usual response is a very small “burst” in oxygen consumption, but very large bursts are sometimes obtained. 2. When the cells are permitted to stand some hours in saline a substance escapes from them which inhibits the bursts. In its absence the small burst is increased in magnitude, but never to that of the large ones. 3. Numerous variables which do not determine the size of the burst are listed, and evidence is given which indicates that the burst is probably not related to the normal metabolism of the cells. 4. The plasma of normal rabbits consumes a small amount of oxygen (about 1·7 mm.3/c.c./hr.). This is probably due to autoxidation of the lipoids and proteins present. 5. The oxygen consumption of plasma is increased to show a burst when cells are haemolysed in it or when non-respiring haemolysed cells are added. This burst is heat-stable and only slightly cyanide-sensitive. It is probably due to catalysis of lipoid and protein autoxidation by the pigments of the lysed cells. 6. When rabbit blood-cells are suspended in plasma the observed oxygen consumption is the sum of that due to the cells and that of the plasma.
A planar resonant-tunneling field-effect transistor

Summary form only given. The authors report on the fabrication of double-barrier planar resonant-tunneling field-effect transistors. The layers used are modulation-doped GaAs/AlGaAs heterostructures grown by molecular beam epitaxy. The devices can be operated in a regular FET mode by lowering the gate-induced barriers below the Fermi energy. A clear oscillatory behavior of the source-drain current I/sub DS/ as a function of gate bias V/sub GS/ below threshold can be observed at 4.2 K, with both gates connected together, a manifestation of resonant tunneling. >
Method for calculating self-noise spectra and operating ranges for seismographic inertial sensors and recorders

Understanding the performance of sensors and recorders is prerequisite to making appropriate use of them in seismology and earthquake engineering. This paper explores a critical aspect of instrument performance, the “self” noise level of the device and the amplitude range it can usefully record. Self noise limits the smallest signals, while instrument clipping level creates the upper limit (above which it either cannot produce signals or becomes unacceptably nonlinear). Where these levels fall, and the “operating range” between them, determines much of the instrument's viability and the applications for which it is appropriate. The representation of seismic-instrument self-noise levels and their effective operating ranges (cf., dynamic range) for seismological inertial sensors, recorders (data acquisition units, or DAUs), and integrated systems of sensors and recorders (data acquisition systems, or DASs) forces one to address an unnatural comparison between transient finite-bandwidth signals, such as earthquake records, and the instrument's self noise, an effectively stationary signal of infinite duration. In addition to being transient, earthquakes and other records of interest are characterized by a peak amplitude and generally a narrow, peaked spectral shape. Unfortunately, any power spectrum computed for such transient signals is ill defined, since the maximum of that spectrum depends strongly upon signal and record durations. In contrast, the noise floor of an instrument is approximately stationary and properly described by a power spectral density (PSD) or its root (rPSD). Put another way, earthquake records have units of amplitude ( e.g. , m/s2) while PSDs have units of amplitude-squared per hertz ( e.g. , (m/s2)2/Hz) and the rPSD has units of amplitude per root of hertz ( e.g. , (m/s2)/Hz1/2). Thus, this incompatability is a conflict between earthquake (amplitude) and PSD (spectral density) units that requires one to make various assumptions before they can be compared. …
Nursing Home Policies on Items Brought in From the Outside for Facility Residents

Objective To identify nursing home standards related to items brought in from the community for residents through a nationwide survey of directors of nursing. Specifically we examined the policies with regard to food, cigarettes, alcoholic beverages, and over-the-counter medications. Methods A national survey was distributed online and was completed by 299 directors of nursing of skilled nursing facilities. The directors of nursing were asked about policies regarding whether family and friends of residents are permitted to bring in items such as food, cigarettes, alcohol, and over-the-counter medications. Specifically, questions were related to monitoring, staff involvement, safety precautions, and policy implementation. Results The results of the survey demonstrated a consistent policy practiced among facilities. Items commonly restricted for all residents included over-the-counter medications, alcohol, and cigarettes. On the other hand, food was significantly less likely to be restricted. Conclusion Despite overall strict policies regarding the monitoring of access to over-the-counter medications, alcohol, and cigarettes by nursing home residents, ingestion of outside food remains fairly unrestricted. This is especially concerning given the growing number of residents with end-stage congestive heart failure, diabetes, dysphagia, or food allergies where access to outside food could result in an adverse event. Perhaps, facilities need to identify at-risk residents and better communicate to residents and their families regarding dietary restrictions on outside food.
Analysis of PIC and total mass emissions from an incinerator

Abstract The destruction of Resource Recovery and Conservation Act Appendix VIII compounds in hazardous waste incinerators and their residual stack emissions have been studied extensively. Complete characterization of organic compounds emitted in all effluents from an incinerator has not been conducted. This paper presents study plans and preliminary results of such a characterization, to the extent that the emitted compounds can be identified and quantified. Measurements will be made of both Appendix VIII and non-Appendix VIII compounds in all effluents (stack, ash, water, etc.) from an incinerator operating both under steady state conditions and during typical transient conditions. A broad array of sampling and analysis techniques will be used. Sampling methods include Modified Method 5, volatile organic sampling train, and specific techniques for compounds such as formaldehyde; and analysis techniques include gas chromatography, gas chromatography/mass spectrometry, and high performance liquid chromatography. Continuous measurements will also be made for a variety of compounds including total hydrocarbons by flame ionization detector.
Mechanism of excitation block by the insecticide allethrin applied externally and internally to squid giant axons.

Abstract The mechanisms of excitability block by allethrin have been studied by means of internal electrode, internal perfusion, and sucrose-gap voltage-clamp techniques in the giant axons of the squid. Allethrin at a concentration of 10–100 μM blocked the action potential with slight depolarization either from inside or from outside the nerve membrane. The effect was partially reversible. The membrane currents associated with step depolarizations were inhibited by allethrin. With external application of allethrin, the early transient component of the membrane conductance was more strongly inhibited than the late steady-state component, whereas both components were inhibited to the same extent by internal application of allethrin. The time to peak early transient membrane current was slightly delayed either by external or by internal application of allethrin. There was an indication that with internal application of allethrin the sodium conductance increase was not as quickly inactivated as normal. The excitability block by allethrin can primarily be ascribed to the inhibition of the early transient membrane conductance. Further mechanisms of allethrin action are discussed in comparison with other blocking agents.
Measurements of functional outcomes in children with cerebral palsy

This review describes functional measures applicable to children, adolescents, and young adults with cerebral palsy. The World Health Organization (WHO) and National Center for Medical Rehabilitation Research (NCMRR) Models of Impairment, Functional Limitations, Disability, Social Limitations, and Handicap as applied to persons with cerebral palsy are discussed. Motor measurements of impairment include developmental postural control, gross motor function and motor performance rates, and various classifications of cerebral palsy severity. Measures of functional skills in daily living include the Pediatric Evaluation of Disability Inventory (PEDI), Pediatric Functional Independence Measure (WeeFIM), Vineland Adaptive Behavior Scales (VABS), Scales of Independent Behavior (SIB), and Battelle Developmental Inventory. Measures of handicap include family stressors, extended activities of daily living, and health-related quality-of-life. If the promise of legislative policies and family-centered support programs are to be realized, research is required to evaluate the functional effects of developmental therapies, assistive technologies, neuropharmacology, surgical interventions, and educational curricula. MRDD Research Reviews 3:194-203, 1997. © 1997 Wiley-Liss, Inc.
“Nothing Exists Except an Earthenware Pot”: Resisting Sovereignty on Robinson’s Island

In this essay I would like to focus on “The Beast and the Sovereign”—and especially the Second Volume—as being something of an exception to Derrida’s usual hesitations about sovereignty. In other works, such as “Rogues”, Derrida displays a deep ambivalence about sovereignty insofar as for all of his condemnation of sovereign authority, he fears that what might replace it could be even worse (and, to be fair, he also sees positive aspects of sovereignty as well). In “The Beast and the Sovereign,” we find evidence of this ambivalence as well but here, Derrida comes a bit closer to the kind of position advocated by Walter Benjamin wherein sovereignty is an idolatrous practice of politics one which must not be eliminated so much as subverted. In particular, I focus on Derrida’s reading in Volume II of “Robinson Crusoe” as a text that both founds the sovereign subject and subverts it (by revealing its vulnerability, its fictional nature). In looking at how the book disappoints as much as it answers sovereign phantasms of authority and unity, I argue that Derrida transfers his own ambivalence about sovereignty to sovereignty itself, subverting and rupturing its central tenets in the process.
Retreat of glaciers on Puncak Jaya, Irian Jaya, determined from 2000 and 2002 IKONOS satellite images

Puncak Jaya, Irian Jaya, Indonesia, contains the only remaining tropical glaciers in East Asia. The extent of the ice masses on Puncak Jaya has been mapped from high-resolution IKONOS satellite images acquired on 8 June 2000 and 11 June 2002. Exclusive of Southwall Hanging Glacier, the ice extent on Puncak Jaya was 2.326km 2 and 2.152km 2 in 2000 and 2002, respectively. From 2000 to 2002, the Puncak Jaya glaciers lost a surface area of 0.174km 2 or 7.48% of their 2000 ice extent. Comparison of the IKONOS-based glacier extents with previous glacier extents demonstrates a continuing reduction of ice area on Puncak Jaya. By 2000, ice extent on Puncak Jaya had reduced by 88% of its maximum neoglacial extent. Between 1992 and 2000 Meren Glacier disappeared entirely. All remaining ice masses on Puncak Jaya continue their retreat from their neoglacial maxima. Comparison of 2000/2002 ice extents with previous extents suggests that these glaciers have not experienced accelerating rates of retreat during the last half of the 20th century. If the recession rates observed from 2000 to 2002 continue, the remaining ice masses on Puncak Jaya will melt within 50 years.
Nonlinear excitation of capillary waves by the Marangoni motion induced with a modulated laser beam.

We have studied the amplitude and phase relationships of capillary waves produced by modulated laser light on the surface of strongly absorbing liquids. For increasing laser fluences a strong nonlinear behavior is observed. This is connected with the convective motion of the liquid created by surface tension gradients known as the Marangoni motion. The abrupt changes in both the capillary wave amplitude and the phase are found to be due to an autoblocking effect of the heat flux from the region of the laser absorption as the result of the development of a closed circulating flow of the liquid.
Extended drug delivery by contact lenses for glaucoma therapy

Abstract We combine laboratory-based timolol release studies and in vivo pharmacodynamics studies in beagle dogs to evaluate the efficacy of glaucoma therapy through extended wear contact lenses. Commercial contact lenses cannot provide extended delivery of ophthalmic drugs and so the studies here focused on increasing the release duration of timolol from ACUVUE® TruEye™ contact lenses by incorporating vitamin E diffusion barriers. The efficacy of timolol delivered via extended wear contact lenses was then compared to eye drops in beagle dogs that suffer from spontaneous glaucoma. The lenses were either replaced every 24 h or continuously worn for 4 days, and the pharmacodynamics effect of changes in the intraocular pressure (IOP) of timolol from the ACUVUE® TruEye™ contact lenses can be significantly increased by incorporation of vitamin E. The in vivo studies showed that IOP reduction from baseline by pure contact lens on daily basis was comparable with that by eye drops but with only 20% of drug dose, which suggested higher drug bioavailability for contact lenses. In addition, by inclusion of vitamin E into the lenses, the IOP was reduced significantly during the 4-day treatment with continuous wear of lens.
Adaptive Prognostics for Rotary Machineries

Abstract The success of condition-based-maintenance (CBM) of mechanical components, in terms of cost and reliability, hinges closely on the ability to accurately estimate the remaining life of the components at point. In the case of rotary machineries, special attention for remaining life estimation is warranted in view of the dynamic behaviors associated with repetitive contact motions. This paper discusses the rotary machinery prognostics using rolling element bearing – one of the foremost causes of breakdown in rotary machinery – as an example to illustrate the treatments of self-leaning prediction of remaining life. To date bearing remaining life prediction issue has not been fully addressed, as a result of the highly random nature of the bearing defect growth behavior in fatigue cycles. This paper addresses the lack of current bearing condition monitoring techniques by proposing a remaining life adaptation methodology based on the approaches of mechanistic modeling of vibration and self-training of parameter adaptation, thus the instantaneous rate of defect propagation can be apprehended, even when the initial health condition is unknown and the defect growth behavior is time-varying, to deliver a reliable prediction of the remaining life.
Erratum: Iron biofortification and homeostasis in transgenic cassava roots expressing an algal iron assimilatory protein, FEA1.

We have engineered the starchy root crop cassava (Manihot esculenta) to express the Chlamydomonas reinhardtii iron assimilatory protein, FEA1, in roots to enhance its nutritional qualities. Iron levels in mature cassava storage roots were increased from 10 to 36 ppm in the highest iron accumulating transgenic lines. These iron levels are sufficient to meet the minimum daily requirement for iron in a 500 gm meal. Significantly, the expression of the FEA1 protein did not alter iron levels in leaves. Transgenic plants also had normal levels of zinc in leaves and roots consistent with the specific uptake of iron mediated by the FEA1 protein. Relative to wild-type plants, FEA1 expressing plants had reduced Fe(III) chelate reductase activity and gene expression levels consistent with the more efficient uptake of iron in FEA1 transgenic plants. We also show that genes involved in iron homeostasis in cassava have altered tissue-specific patterns of expression in transgenic plants. Steady state transcript levels of the metal-chelate transporter MeYSL1, and the iron storage proteins, MeFER2 and MeFER6, were elevated in various tissues of FEA1 transgenic plants compared to wild-type plants. These results suggest that these gene products play a role in iron translocation and homeostasis in FEA1 transgenic cassava plants. These results are discussed in terms of enhanced strategies for the iron biofortification of plants.
Developing acquired foreign subsidiaries: the experience of MNES in transition economies

Drawing on subsidiary evolution and dynamic capabilities research, I test how development and growth of subsidiaries recently acquired in transition economies are affected by multinational enterprise (MNE) and target capabilities. These subsidiaries often lack important resources; their cross-border transfer, enhancement, and exploitation are problematic, however. Data on 170 acquisitions in Central and Eastern Europe confirmed the importance of the pre-acquisition experiences of both target and MNE for subsidiary growth, although cultural differences moderated the predicted effects notably.
Convective instabilities during the solidification of an ideal ternary alloy in a mushy layer

We consider a model for the solidification of an ideal ternary alloy in a mushy layer that incorporates the effects of thermal and solutal diffusion, convection and solidification. Our results reveal that although the temperature and solute fields are constrained to the liquidus surface of the phase diagram, the system still admits double-diffusive modes of instability. Additionally, modes of instability exist even in situations in which the thermal and solute fields are each individually stable from a static point of view. We identify these instabilities for a general model in which the base-state solution and its linear stability are computed numerically. We then highlight these instabilities in a much simpler model that admits an analytical solution.
Hydroxyl Radical Production via the Photo-Fenton Reaction in the Presence of Fulvic Acid

The photo-Fenton reaction, the reaction of photoproduced Fe(II) with H2O2 to form the highly reactive hydroxyl radical (OH*), could be an important source of OH* in sunlit natural waters. To determine if the photo-Fenton reaction is significant in mildly acidic surface waters, we conducted experiments simulating conditions representative of natural freshwaters using solutions of standard fulvic acid and amorphous iron oxide at pH 6.0. A probe method measuring 14CO2 produced by the reaction of 14C-labeled formate with OH* was used to detect small OH* production rates without otherwise influencing the chemical reactions occurring in the experiments. Net H2O2 accumulation was simultaneously measured using an acridinium ester chemiluminescence method. Measured losses of H2O2 by reaction with Fe(II) in dark experiments produced approximately the expected quantities of OH*. The difference between H2O2 accumulation in the presence and absence of Fe(III) in fulvic acid solutions exposed to light was interpreted as the loss of H2O2 by reaction with photoproduced Fe(II), consistent with measured OH* production rates. The Fe ligand desferrioxamine mesylate eliminated both OH* production and H2O2 photoloss induced by Fe. Our results imply that when Fe is a major sink of H2O2, the photo-Fenton reaction is likely to be the most important source of OH*, leading to a significant sink of organic compounds in a wide variety of sunlit freshwaters.
The effect of tyrosine-deficient total parenteral nutrition on the synthesis of dihydroxyphenylalanine in neural tissue and the activities of tyrosine and branched-chain aminotransferases

The poor solubility of tyrosine (Tyr) limits the amount of this amino acid in total parenteral nutrition (TPN). In rats maintained on a standard pediatric TPN mixture, plasma and brain concentrations of Tyr are reduced to about 25% of the levels in chow-fed controls. To determine whether these low concentrations of Tyr affect the synthesis of catecholamines in neural tissue, the rate-limiting step (conversion of Tyr to dihydroxyphenylalanine [DOPA]) is studied by administering NSD-1015 to block the pyridoxal phosphate (PLP)-dependent decarboxylation of DOPA. However, in TPN rats, plasma concentrations of Tyr are increased by drug treatment. Because brain Tyr is also increased, these and other experiments using NSD-1015 clearly overestimate the rate of DOPA synthesis for drug-free rats on TPN. Nevertheless, in TPN rats, there is less DOPA in the brain in one experiment and less DOPA in the olfactory bulbs in another, versus control rats. Further examination of the metabolic effects of NSD-1015 reveals that the drug also elevates the concentration of branched-chain amino acids (BCAAs) in the plasma of TPN rats. These findings result from inhibition by NSD-1015 of the PLP-dependent aminotransferases that initiate catabolism of Tyr in the liver and BCAAs in the muscle. Despite the pronounced reduction in plasma Tyr, TPN rats showed a marked increase in the activity of hepatic Tyr aminotransferase compared with chow-fed controls. Conversely, although TPN elevates BCAA concentrations in plasma, the activity of branched-chain aminotransferase (BCAT) in the heart muscle of TPN rats is not different from control values. Different values but the same relationships are seen in drug-free rats.
Optical spectra of glasses

Abstract This presentation focuses on several ways in which structural and dynamical information can be obtained from optical spectroscopy by examining results of infrared and Raman studies of selected oxide glasses. Though these studies represent only a small fraction of the work on most of the glasses mentioned, and many other important forms of optical spectroscopy are not treated here, they illustrate useful approaches to the study of amorphous materials by optical methods.
Performance of large inert-gas thrusters

The performance of large inert-gas thrusters is predicted based on present knowledge of ion optics performance and discharge chamber operation. Calculated performance data are given for argon and xenon propellants. The effect of varying propellant utilization and thruster diameter is discussed and the optimum choice of beam diameter for very large systems is indicated for low, intermediate, and high specific impulses. Optimum discharge chamber depths are also specified. Although detailed design considerations may modify the predictions, the general trends indicated should still be useful for directing future technology efforts and evaluating mission studies involving large thrusters.
How trustworthy are the standard errors of translog coefficients

Abstract A simulation study indicates that the conventionally computed asymptotic standard errors of the ML estimates of the parameters of the indirect translog model underestimate the true variability of these estimates.
Development and Validation of the Virgilio Teacher Behavior Instrument

This study was an attempt to develop an easily coded, research-oriented instrument to assess teacher effectiveness in the class- room. A 35-item Likert format scale was developed which included three subscales of teacher effectiveness: classroom management, instruction, and classroom climate. The results of the study indicated that the Virgilio Teacher Behavior Inventory (VTBI) is a reliable and valid instrument which can be administered with confidence either in elementary or junior high schools. Instrument development included the generation of an initial pool of 80 items which was refined during pilot testing to a final 35-item version. Content validity of the VTBI was indicated by an assessment of a panel of judges. Estimates of internal consistency (coefficient alpha) were .96 for the total inventory and .88, .96, and .85 for the classroom management, instruction, and classroom climate subscales, respectively. The relationship between the VTBI and a time-on-task measure (r = .64, p < .0001) provided ...
MODIFICATION OF THE CLOZE PROCEDURE AND CHANGES IN READING TEST PERFORMANCES1

In general, the cloze procedure is a means of measuring the degree of correspondence between the language of a message and the language system of a reader. To the extent that the reader's language facility allows him to utilize the semantic and syntactic information in a passage, he is able to complete the cloze task and communication (comprehension) is assumed to have occurred. A passage that uses an unknown vocabulary or grammatical patterns different from those of the reader is difficult for the reader to complete. Also, a reader with a limited vocabulary or restricted grammatical sophistication has more difficulty in completing a given passage than does a more adequate reader.
Functional magnetic resonance (fMR) imaging of a rat brain tumor model: implications for evaluation of tumor microvasculature and therapeutic response

Functional MR (fMR) imaging techniques based on blood oxygenation level dependent (BOLD) effects were developed and applied to a rat brain tumor model to evaluate the potential utility of the method for characterizing tumor growth and regression following treatment. Rats bearing 9L brain tumors in situ were imaged during inhalation of room air and after administration of 100% oxygen + acetazolamide (ACZ) injected 15 mg/kg intravenously. Pixel-to-pixel fMR maps of normalized signal intensity change from baseline values were calculated from T2 weighted spin echo (SE) images acquired pre- and post- oxygen + ACZ administration. Resultant fMR maps were then compared to gross histological sections obtained from corresponding anatomical regions. Regions containing viable tumor with increased cellular density and localized foci of necrotic tumor cells consistent with hypoxia were visualized in the fMR images as regions with decreased signal intensities, indicating diminished oxyhemoglobin concentration and blood flow as compared to normal brain. Histological regions having peritumor edema, caused by increased permeability of tumor vasculature, were visualized in the fMR images as areas with markedly increased signal intensities. These results suggest that fMR imaging techniques could be further developed for use as a non-invasive tool to assess changes in tumor oxygenation/hemodynamics, and to evaluate the pharmacologic effect of anti-neoplastic drugs.
The relationship between insulin resistance and dyslipidaemia in cigarette smokers.

Aim: Considerable evidence shows that cigarette smokers tend to have the dyslipidemic pattern of high plasma triglyceride (TG) and low high-density lipoprotein cholesterol (HDL-C) concentrations, a highly atherogenic lipoprotein profile also typical of the insulin-resistant state even in the absence of cigarette smoking. However, because cigarette smokers are frequently insulin resistant, it is unclear if this dyslipidaemia is secondary to smoking, per se, or simply to the fact that smokers tend to be insulin resistant. The present study was initiated to determine whether this dyslipidaemia prevalent in cigarette smokers and characteristic of insulin-resistant individuals is a function of cigarette smoking or of insulin resistance. Methods: As measured using vertical auto profile-II methodology, the lipid and lipoprotein concentrations were compared in 34 cigarette smokers divided into insulin-sensitive and insulin-resistant subgroups. The two groups were similar in age and body mass index, differing only in their insulin-mediated glucose uptake as quantified by the steady-state plasma glucose concentration determined during the insulin suppression test. Results: While levels of TG and very low-density lipoprotein cholesterol (VLDL-C) were significantly elevated in insulin-resistant cigarette smokers, total cholesterol (C), low-density lipoprotein cholesterol (LDL-C), narrow-density (ND) LDL-C, intermediate-density lipoprotein-C (IDL-C), HDL-C and non-HDL-C were not different in the two groups. The insulin-resistant smokers also had a preponderance of small, dense LDL particles, while the reverse was true of the insulin-sensitive cigarette smokers. Conclusions: These data suggest that the dyslipidaemia previously attributed to smoking occurs primarily in those smokers who are also insulin resistant.
X-ray induced mutations, DNA and target theory.

THAT X-ray induced, specific locus, germ-line mutation rates vary significantly in eukaryotes is generally known, but the factors that are responsible for such differences have not been assessed in detail. It was recently proposed1 for a variety of species that mutability is closely and simply related to total DNA per genome. This approach, however, has not stood the test of critical review2; in fact, even within one species (mouse) there are major differences between the rates for different genes, and even for different germ cells3–5. I have therefore taken a different approach by considering the radiobiology of the individual gene. The analysis leads to three major conclusions. (1) Mutation rates tend to be much lower than radiation theory predicts. (2) Selection and/or repair are major factors that determine the rates. (3) The mouse 7-locus test, which provides a principal data base for the standards of human radiation hygiene, may not provide adequate overall representation of the mutability of the mammalian genome, so more research is needed.
Epilepsy surgery and the racial divide

Racial minorities in the United States receive poorer quality health care and have poorer health outcomes than do nonminorities.1 Differences in economic status and health insurance rates explain some but not all of the disparities in quality of care. There is no evidence that racial differences in health care quality and outcomes are caused by inherent differences in disease or in response to treatment.2 In this issue of Neurology , Burneo et al.3 present a study of seizure surgery among blacks and whites discharged from the University of Alabama at Birmingham hospital after video-EEG monitoring between 1998 and 2000. They studied 130 patients with refractory temporal lobe epilepsy caused by mesial temporal lobe sclerosis. Using multivariate analyses that accounted for socioeconomic status, the authors demonstrated that race is independently associated with a lower likelihood of epilepsy surgery. The results of this study concur with those of others investigating disparities in the use of surgical procedures.1 Why would black patients referred to the same center with the same diagnosis have a lower likelihood of undergoing epilepsy surgery? Patient and physician factors …
TH-C-224C-04: Radiobiological Concerns On Prolonged IMRT Delivery for Head-And-Neck Carcinoma

Purpose: Radiobiological effect of the prolonged IMRT delivery time on head‐and‐neck cancer has remain to be defined. The purpose of this work is to estimate a plausible set of radiobiological parameters (α/β, sublethal damage repair halftime, potential doubling time) for squamous cell carcinomas of head‐and‐neck (SCCHN) based on in vitro measurement and clinical data, and to examine the potential radiobiological influence due to the prolonged delivery time using the newly estimated parameters of SCCHN. Methods and Materials: In vitro cell survival measurements were performed for two cell lines of SCCHN irradiated by a series of specially‐designed single and split dose regimens using a 6 MV machine. The obtained survival data were fitted to the Linear‐Quadratic (LQ) model using the least χ2 technique. Other radiobiological models, such as equivalent uniformly dose (EUD) and tumor control probability (TCP), were used to analyze published clinical outcome to validate the parameters estimated from the in vitro data. Results: Based on the present in vitro measurements, we have estimated a set of radiobiological parameters for SCCHN: repair half‐time Tr = 16 ± 21 min, the potential doubling time Td = 48 ± 10 hours, radiosensitivity parameters α/β = 7.9 ± 4.5 Gy, α = 0.22 ± 0.08 Gy. This set of parameters was found to be able to fit the available clinical data. The calculation based on these parameters indicated that prolonged delivery time, if comparable/longer with the repair half‐time, would result in noticeable reduction in treatment effectiveness. For example, an IMRT delivery time of 30 minutes would result in a reduction of 11% in tumor EUD (compared to a 5‐minute fraction). Conclusions: The present measurement and analysis show that the repair half‐time and potential doubling time for head‐and‐neck cancer are relatively short, indicating that optimal IMRT delivery time needs to be clinically considered.
ILT3.Fc inhibits the production of exosomes containing inflammatory microRNA in supernatants of alloactivated T cells

Immune activation needs to be tightly regulated to control immune-mediated tissue damage. Inhibitory pathways serve to terminate an immune response and resolve inflammation. Persistent exposure to antigens can drive development of adaptive regulatory cells. Similarly exposure of activated T cells to the recombinant ILT3-Fc molecule during priming triggers the differentiation of CD8 T suppressor cells and the induction of CD4 T helper anergy. Ts express high levels of immunoregulatory signature genes together with low levels of microRNA which control their function. Analysis of microRNA contained by exosomes from cultures in which T cells were alloactivated in the presence or absence of ILT3.Fc, demonstrated that this agent inhibits the release of inflammatory microRNA. The source of such inflammatory microRNA was found to reside in alloactivated CD4 T cells, since exosomes from MLC primed CD4 T cells were shown to diminish the suppressive activity of ILT3-Fc-induced CD8+ Ts at high effector to suppressor T cell ratios. This indicates that inflammatory exosomes can swing the balance between effector and regulatory T cells in favor of immunity. These data suggest that isolation and characterization of micro-RNA containing exosomes in patients’ circulation may be of use for treatment, prevention and monitoring of immune activation.
Homomorphisms of progenerator modules under a change of base ring

A covariant functor has been defined in [1] which assigns to a commutative ring R an abelian monoid m(R). The elements of m(R) are equivalence classes (called homotopy classes) of homomorphisms of progenerator modules over R. The monoid homomorphism m(σ): m(R) → m(S) associated with a homomor-phism of rings σ: R → S is studied. Both necessary condi­tions and sufficient conditions for m(σ)1 {1} = {1}, for m(σ) to be injective and for m(σ) to be surjective are presented.
Toward a Spatially-Resolved Model of Metabolism in Dense Bacterial Colonies

An individual cell's metabolic behavior is dependent on several factors, including both its protein-expression state as well as the availability of nutrients in its local environment. These two factors are not always independent; several transcription and translational regulatory systems allow the cell to respond to changes in its environment by adjusting the expression of metabolic enzymes, and thereby shifting its usage among different substrates. By integrating two methods for modeling whole cell phenomena, namely time-dependent reaction-diffusion master equation (RDME) sampling and steady-state flux-balance analysis (FBA), we are able to study how the competition for resources among bacteria in a dense colony gives rise to local micro-environments, and how these micro-environments in turn give rise to drastically different metabolic behaviors among cells. We find, in particular, that cooperative behavior can emerge among cells within the colony. Cells in the anaerobic interior of the colony partially metabolize glucose to acetate, which can then be taken up and metabolized by cells on the more aerobic periphery of the colony.
Vision-based stereo ranging as an optimal control problem

The recent interest in the use of machine vision for flight vehicle guidance is motivated by the need to automate the nap-of-the-earth flight regime of helicopters. Vision-based stereo ranging problem is cast as an optimal control problem in this paper. A quadratic performance index consisting of the integral of the error between observed image irradiances and those predicted by a Pade approximation of the correspondence hypothesis is then used to define an optimization problem. The necessary conditions for optimality yield a set of linear two-point boundary-value problems. These two-point boundary-value problems are solved in feedback form using a version of the backward sweep method. Application of the ranging algorithm is illustrated using a laboratory image pair.
Laser velocimetry measurements in an MHD aerodynamic duct

Fluid flow profile measurements made by a laser Doppler velocimeter just downsteam of the combustor nozzle at the DOE Coal-Fired Flow Facility at the University of Tennessee Space Institute are described. Attention is given to a proof-of-concept test program consisting of long-duration coal-fired tests of equipment that is envisioned for use in an MHD power system. A combination of high velocities, intense background radiation, small particle sizes, and a small-diameter collection aperture resulted in low amplitude signal bursts. A forward scatter detection configuration would significantly improve signal quality for these measurement conditions. 6 refs.
Revisiting Oral Barium Sulfate Contrast Agents

Oral contrast agents used during CT colonography (CTC) are valuable and may reduce false positive and false negative detections due to stool and residual fluid. Electronic cleansing algorithms are feasible, and oral contrast agents can eliminate the CTC requirement for a clean colon. Recent work shows oral contrast frequently adheres to polyps, with a preference for those with villous histology, a characteristic of advanced polyps. This finding encourages the development of contrast agents that highlight polyps at greatest risk for progression to malignancy. Our review summarizes numerous aspects of oral barium sulfate contrast agents as well as tests to assess adherence and coating ability of the agents, offering arenas to explore and tools for evaluation.
Phase-Field Simulation of Long-Wavelength Line Edge Roughness in Diblock Copolymer Resists

We examine stochastic computer simulations of the Leibler-Ohta-Kawasaki (LOK) phase-field model [1,2] and demonstrate that long-wavelength line edge roughness (LER) and line width roughness (LWR) in a lamellar diblock copolymer resist depend monotonically on quench depth and noise strength, and that the LER and LWR spectra both exhibit a peak at k 0 -the characteristic wave-number of mesophase separation in diblock copolymers. For k ≲ k o , we find that the LER spectrum approximately scales like k -1.6 . These observations are consistent with previous theoretical, computational, and experimental examinations LER and LWR in diblock copolymer melts, and thus the LOK phase-field model should be considered a capable and appropriate framework for future examination of long-wavelength LER and LWR in block copolymer resist systems.
High-risk carotid endarterectomy: challenges for carotid stent protocols

Abstract Background: Carotid angioplasty and stenting is under investigation in clinical trials as an alternative to endarterectomy. Some clinicians have hypothesized that stenting would be applicable for patients at high risk who need carotid revascularization. To further test this hypothesis, we stratified our carotid endarterectomy procedures according to current carotid stent protocols. Methods: We reviewed our computerized registry and the clinical charts of patients who underwent carotid endarterectomy. Each procedure was categorized as high risk or low risk, according to the following six separate high-risk factors: 1, severe cardiac dysfunction; 2, the requirement for combined coronary and carotid vascularization; 3, severe pulmonary dysfunction; 4, contralateral internal carotid artery occlusion; 5, previous ipsilateral carotid endarterectomy; and 6, anatomically limited access for carotid endarterectomy. Rates of stroke at 30 days, cardiac complications, and death were tabulated Results: Between January 1, 1998, and December 31, 2000, 415 carotid endarterectomies were performed on 389 patients. Ninety-eight procedures (23.6%) were classified as high risk on the basis of the following factors: 1, severe cardiac dysfunction (n = 30); 2, requirement for combined coronary and carotid revascularization (n = 14); 3, severe pulmonary dysfunction (n = 8); 4, contralateral carotid occlusion (n = 31); 5, previous ipsilateral carotid endarterectomy (n = 25); and 6, anatomically limited access (n = 4). Seven patients had ipsilateral postoperative strokes (1.7%), with two additional patients having contralateral hemispheric strokes. One patient died from exacerbation of congestive heart failure 9 days after undergoing a second carotid endarterectomy. The total stroke and death rate was 2.6% for all the patients. Two of the 98 procedures in the high-risk group were complicated with ipsilateral stroke (2.0%) as compared with six of the 317 low-risk procedures (1.9%; P = 1). Six procedures were complicated with cardiac dysfunction after surgery, including myocardial infarction, congestive heart failure, or the new onset of atrial fibrillation. Three cardiac complications occurred in the low-risk group (1%), and three occurred in the high-risk group (3.1%; P =.15) Conclusion: This series shows that patients at high risk can undergo carotid endarterectomy with stroke rates equivalent to the rates of patients at low risk. The cardiac morbidity rate may be increased in the high-risk group. Carotid stenting is unlikely to offer any improvement in stroke risk as compared with carotid endarterectomy, but stenting may reduce non-stroke morbidity rates associated with some high-risk cases. (J Vasc Surg 2002;35:16-22.)
A simple class of U( N) Racah coefficients and their application

Using permutation group techniques, a general expression is derived for the special class ofU(N) Racah coefficients for which the representations [f1] and [f3] in the recoupling matrix for [f1]×[f2]×[f3]→[f] are either both totally antisymmetric or both totally symmetric. For the totally antisymmetric case further specialization gives a simple expression for aU(N) Racah coefficient which is needed in taking the average of the product of operators over the states of an irreducible representation ofU(N), where this result can be useful in the study of identical fermion systems by spectral distribution methods.
Structure of a Psoralen Cross-Linked DNA in Solution by Nuclear Magnetic Resonance

One- and two-dimensional nuclear magnetic resonance (NMR) methods were used to determine a three-dimensional model of an eight-base-pair DNA fragment (d-GGGTACCC) cross-linked with psoralen in solution. Two-dimensional nuclear Overhauser effect experiments were used to assign the spectrum and estimate distances for 171 proton pairs in the cross-linked DNA. The NMR-derived model shows a 53 degree bend into the major groove that occurs primarily at the site of drug addition and a 56 degree unwinding that spans the eight-base-pair duplex.