cssi/SciSciGPT-SciSciNet huggingface dataset:
Stabbing Delaunay Tetrahedralizations

A Delaunay tetrahedralization of $n$ vertices is exhibited for which a straight line can pass through the interiors of $\Theta(n^2)$ tetrahedra. This solves an open problem of Amenta, who asked whether a line can stab more than $O(n)$ tetrahedra. The construction generalizes to higher dimensions: in $d$ dimensions, a line can stab the interiors of $\Theta(n^{\lceil d / 2 \rceil})$ Delaunay $d$-simplices. The relationship between a Delaunay triangulation and a convex polytope yields another result: a two-dimensional slice of a $d$-dimensional $n$-vertex polytope can have $\Theta(n^{\lfloor d / 2 \rfloor})$ facets. This last result was first demonstrated by Amenta and Ziegler, but the construction given here is simpler and more intuitive.
Dynamics of 2-worker bucket brigade assembly line with blocking and instantaneous walk-back

We analyze the dynamics of 2-worker m-stations bucket brigade assembly lines where the velocities of the workers on the stations are arbitrary, albeit fixed constants over each station. We provide a complete characterization of the dynamics under blocking and instantaneous walk-back.
Comparative effects of propofol, pentobarbital, and isoflurane on cerebral blood flow and blood volume.

While intravenous and volatile anesthetics have widely differing effects on cerebral blood flow (CBF), clinical studies suggest that the relative differences in their effects on intracranial pressure (ICP) may be smaller. Because acute changes in ICP are determined primarily by changes in cerebral blood volume (CBV), we compared the impact of propofol, pentobarbital, and isoflurane on CBF and CBV in rats. Equipotent doses of the three agents were determined by tail-clamp studies. Animals were then anesthetized with propofol (20 mg/kg load, 38 mg.kg-1.h-1 infusion), pentobarbital (30 mg/kg load, 20 mg.kg-1.h-1 infusion), or isoflurane 1.6-1.8%. Two hours later, CBF and CBV were measured using 3H-nicotine as a CBF tracer, and 14C-dextran and 99mTc-labeled red cells as markers for cerebral plasma and red blood cell volumes (CPV and CRBCV), respectively. Total CBV was the sum of CPV and CRBCV. CBF was 2.0-2.6 times greater with isoflurane than with propofol or pentobarbital (137 vs. 67 and 52 ml.100 g-1.min-1, respectively). By contrast, while CBV was greater in the isoflurane group than in either the propofol or pentobarbital groups, the magnitude of the intergroup differences were much smaller (propofol = 2.49 +/- 0.28 ml/100 g; pentobarbital = 2.27 +/- 0.15 ml/100 g; isoflurane = 2.77 +/- 0.24 ml/100 g, mean +/- SD). These results suggest that the simple measurement of CBF may not adequately describe the cerebrovascular effects of an anesthetic, at least with respect to predicting the magnitude of the agents likely effects on ICP.
Variation of Radiation Sensitivity of Paramecium aurelia as a Function of Time of Irradiation in the Interdivision Growth Cycle

THE larger ciliate protozoa provide a system which is particularly favourable for the investigation of the relationship between radiation sensitivity and events in vegetative growth and division. Individual animals can be isolated in the visible stages of cell division in sufficient numbers to provide a synchronized population for experimentation. Synchronization in this manner produces a minimum of the growth abnormalities which occur when synchronization is produced by such means as heat shock or antibiotics.
The spectropolarimetric back-titrations of tin(IV) and antimony(III) ions from their d-(-)-trans-1,2-cyclohexane-diaminetetraacetate complexes

Abstract Spectropolarimetric back-titrations are described for tin(IV) and antimonyIII); the optically active ligand D-(-)- trans -l,2-cyclohexanediaminetetraacetic acid (D(-)CDTA) is used as the complexing agent and cadmium(II) ion as the backtitrant. The optical rotation is monitored throughout the titration, and the optically active ligand and stereospecifically formed complexes serve as self-indicators. The end-points are determined graphically by straight-line extrapolations from a plot of volume-corrected observed rotations versus ml of titrant. The tin(IV) titration plots are representative of normal Spectropolarimetric back-titrations and the antimony(III) titration plots are representative of spectropolarimetric back-titrations where metal-metal ion exchange occurs after the end-point. These analyses are carried out in aqueous systems and the procedures for both the tin and antimony are rapid and simple.
Metabolism of platelet activating factor by intrapulmonary vascular smooth muscle cells. Effect of oxygen on phospholipase A2 protein expression and activities of acetyl-CoA acetyltransferase and cholinephosphotransferase

We have demonstrated that platelet activating factor (PAF) plays an important physiological role in the maintenance of high pulmonary vascular tone in fetal lambs, a role attributable to increased PAF receptor binding (J. Appl. Physiol. 85 (1998) 1079; Am J. Physiol. 278 (2000) H1168). In this study, we examined the possibility that increased PAF synthesis via de novo and remodeling pathways as well as decreased PAF catabolism in hypoxic state of fetal lungs may account for the PAF action in vivo. We investigated effect of oxygen tension on PAF synthesis by ovine fetal intrapulmonary venous (PV) and arterial (PA) smooth muscle cells pulsed with [3H]choline (de novo), or [3H]acetate (remodeling), while PAF catabolism was studied by assay of acetylhydrolase (PAF-Ah) activity. Hypoxia stimulated PAF synthesis by choline incorporation (pmol/10(6)cells) in both PVSMC (1.14+/-0.13 vs 0.53+/-0.05) and PASMC (0.39+/-0.12 vs 0.22+/-0.04). Hypoxia stimulated PAF synthesis via remodeling pathway only in PVSMC (408+/-32 vs 225+/-17) which was 5-fold greater than in PASMC (77+/-15 vs 105+/-24), however, with A23187 in remodeling pathway, PAF synthesis increased 5-fold compared to baseline conditions and then synthesis in hypoxia was greater than in normoxia in both cell types. Phospholipase A2 protein expression was significantly higher in hypoxia in both cells and was approximately 2-fold higher in PVSMC. PAF-Ah activity (nmol lyso-PAF/min/mg protein) was greater in hypoxia vs normoxia in PVSMC (0.81+/-0.24 vs 0.44+/-0.088), but in PASMC activity was less in hypoxia vs normoxia (1.68+/-0.24 vs 3.93+/-0.44). Compared to PVSMC PAF-Ah activity in PASMC was 4-fold higher in hypoxia. Our data demonstrate that (1) PAF synthesis in intrapulmonary SMC of fetal lambs occurs by both de novo studied by choline incorporation and remodeling pathways, the latter being predominant. (2) There is heterogeneity in PAF synthetic and catabolic activities in lung vasculature of fetal lambs. We conclude that increased PAF synthesis in veins by the two synthetic pathways coupled with decreased catabolism will result in a higher venous PAF levels in the hypoxic environment of fetal lungs. We speculate that in vivo, a high PAF level in veins will make more PAF available for binding to its receptors so as to sustain the desired high venous tone in the fetal pulmonary circulation.
Maintenance of GPIIb-IIIa avidity supporting "irreversible" fibrinogen binding is energy-dependent.

Abstract The interaction between fibrinogen and GPIIb-IIIa on stimulated platelets is multiphasic, progressing from reversible to irreversible ligand binding, associated with stabilization of platelet aggregates and clot retraction. Because fibrinogen binding to platelets has been linked to “outside-in” signaling events such as postreceptor occupancy protein tyrosine kinase and phosphatidylinositol-3 kinase activation, this study examined intracellular signaling requirements involved in stabilizing 125I-fibrinogen binding to adenosine diphosphate-treated platelets with selective inhibitors of protein tyrosine kinase (herbimycin A) (10 μmol/L) and phosphatidyl-inositol-3 kinase (Wortmannin) (10 nmol/L) and metabolic inhibitors antimycin A (7.3 μmol/L) and 2 deoxyglucose (6 mmol/L). Preincubation of platelets with herbimycin A or Wortmannin inhibited fibrinogen binding by 80% to 92% and was accompanied by markedly decreased tyrosine phosphorylation of a range of proteins migrating between 60 kDa and 125 kDa. The addition of inhibitors 5 minutes after adenosine diphosphate-induced fibrinogen binding also resulted in decreased tyrosine phosphorylation and dissociation of approximately 50% of bound fibrinogen within 60 minutes but failed to cause dissociation of irreversibly bound fibrinogen. In contrast, platelet exposure to metabolic inhibitors 5 minutes or 60 minutes after fibrinogen binding resulted in complete, spontaneous fibrinogen dissociation. These data suggest that the maintenance of GPIIb-IIIa avidity supporting irreversible fibrinogen binding to intact platelets is not affected by inhibitors of protein tyrosine kinase or phosphatidylinositol-3 kinase but involves other energy-dependent pathways. (J Lab Clin Med 1999;133:398-404)
Gas transport properties of polyarylates part I: Connector and pendant group effects

Gas transport of helium, hydrogen, oxygen, nitrogen, methane, and carbon dioxide gases in a series of polyarylates based on isophthalic acid has been examined. These polyarylates were prepared from bisphenol A, hexafluorobisphenol A, phenolphthalein, and fluorene bisphenol monomers to study the effects of varying the bisphenol connector group size and shape. Substitution of a tertiary butyl group at position five on the isophthalate ring increases polymer permeability. The incorporation of a large, bulky connector group increases gas permeability and maintains permselectivity while the substitution of t-butyl groups increases gas permeability by two- to fourfold but lowers permselectivity. Most of the increases in permeability can be related to increases in the diffusion coefficients of all the gases. All the polyarylates have high glass transition temperatures and may be suitable for high temperature gas separation applications. ©1995 John Wiley & Sons, Inc.
Bubble memories for microcomputers and minicomputers

An analysis has been made of the utilization of 65,536 bit bubble memory chips in small memory hierarchies for microcomputers and minicomputers. Two basic chip organizations were considered. One chip organization was assumed to be equivalent to that of Ypma, Gergis, and Archer with a conventional major minor loop configuration. The other organization considered employed a major-minor loop configuration in which the minor loops were broken into two segments to facilitate stacking and implementation of multilevel hierarchies as suggested by Tung, Chen, and Chang. The analysis shows that a near optimum organization for 65,536-bit chips with segmented minor loops consists of 64 minor loops of 1024 bits with each minor loop broken into a 64-bit segment and a 960-bit segment.
The World Trade Organisation's Doha Cotton Initiative: A Tale of Two Issues

Four West African nations have demanded that the World Trade Organization's Doha Development Agenda include a Cotton Initiative that involves two issues: cutting cotton subsidies and tariffs, and assisting farm productivity growth in Africa. The authors provide estimates of the potential economic impacts of (1) complete or partial removal of cotton subsidies and import tariffs globally, and (2) cotton productivity growth through the adoption of genetically modified (GM) cotton varieties. They use the latest version of the GTAP database and model. Their results confirm that-unlike for other agricultural subsidies and tariffs-for cotton it is subsidy reductions rather than tariff cuts that would make by far the largest impact. For Sub-Saharan Africa the potential gains are huge relative to the effects on that region of reforming other merchandise trade policies. And they could be more than doubled if that reform provided the cash for farmers to take advantage of the biotechnology revolution and adopt GM cotton varieties. But those potential gains, and the affordability of switching to costly GM seed, depend crucially on the extent to which high-income countries are willing to lower domestic support to their cotton farmers.
EFFECTS OF GENDER, AGE, LOCUS OF CONTROL, AND SELF-ESTEEM ON ESTIMATES OF COLLEGE GRADES

Test scores of four age-groups (<19, 20—24, 25—34, 35+ yr.) of students (N = 169) on the Rotter I-E Locus of Control Scale, Coopersmith Self-esteem Inventory, and Marlowe-Crowne Social Desirability Scale were correlated with the students' accuracy in estimating their final course grades. Analysis showed that a combination of either high school self-esteem and internal control (females, 35+ yr. of age) or low school self-esteem and an external locus of control (18- and 19-yr.-old males) were associated with similar unrealistic estimates of classroom grades.
On intercomponent rank tests for the bivariate two-sample location model

The intercomponent rank test suggested by Thompson (1991a) for the bivariate two sample problem is compared with the intracomponent rank test discussed by Puri and Sen (1971) and Hettmansperger (1984) and with the Hotelling T 2 test. Asymptotic relative efficiencies are discussed and the results of a simulation study are presented. Power studies show that for small sample sizes and small Type 1 error rates, say n = 5 and α = .01, the intercomponent rank test of Thompson (1991a) is somewhat liberal and the intracomponent test is quite conservative. For larger sample sizes and larger Type 1 error rates, both rank tests have improved properties under the null hypothesis. In almost all simulated cases, the intercomponent test is more powerful. In light of these studies it is suggested that the intercomponent rank test of Thompson (1991a), which has the added advantage of being easily computed with standard statistical software, is a strong competitor to the intracomponent rank test.
A Likelihood-Based, Counterfactual Approach to Accounting for Treatment Failures in Clinical Trials

Consider a two-armed, placebo-controlled trial in which subjects may experience treatment failure. For ethical reasons, it is necessary to administer emergency or rescue medications for such subjects. However, the emergency medications may bias the set of response measurements. When analyzing the data from clinical trials, the standard approach is to perform an intent-to-treat (ITT) analysis, wherein the data are analyzed according to treatment assignment. Secondary statistical analyses that supplement the ITT analysis can be performed to account for the impact of treatment failures and emergency medications. A likelihood-based, counterfactual approach to supplemental analyses uses the expectation maximization (EM) algorithm for parameter estimation and a likelihood ratio test to test the equality of the placebo and experimental treatment means for subjects who would not fail under either treatment assignment. A simulation study is performed to assess the operating characteristics of the likelihood ratio test. An example from the Asthma Clinical Research Network (ACRN) is used to draw comparisons between the standard ITT procedure and the developed supplemental analysis.
NVO, surveys and archiving ground-based data

The era of extremely large, public databases in astronomy is upon us. Such databases will open (are opening!) the field to new research and new researchers. However it is important to be sure the resources are available to properly archive groundbased astronomical data, and include the necessary quality checks and calibrations. An NVO without a proper archive will have limited usefulness. This also implies that with limited resources, not all data can or should be archived. NASA already has a very good handle on US space-based astronomical data. Agencies and organizations that operate astronomical facilities, particularly groundbased observatories, need to plan and budget for these activities now. We should not underestimate the effort required to produce high quality data products that will be useful for the broader community.
Searching on the secondary structure of protein sequences

In spite of the many decades of progress in database research, surprisingly scientists in the life sciences community still struggle with inefficient and awkward tools for querying biological data sets. This work highlights a specific problem involving searching large volumes of protein data sets based on their secondary structure. In this paper we define an intuitive query language that can be used to express queries on secondary structure and develop several algorithms for evaluating these queries. We implement these algorithms both in Periscope, a native system that we have built, and in a commercial ORDBMS. We show that the choice of algorithms can have a significant impact on query performance. As part of the Periscope implementation we have also developed a framework for optimizing these queries and for accurately estimating the costs of the various query evaluation plans. Our performance studies show that the proposed techniques are very efficient in the Periscope system and can provide scientists with interactive secondary structure querying options even on large protein data sets.
A new multiresolution predictive scheme for lossless compression of medical images

This paper introduces a new multiresolution predictive scheme for lossless compression of medical images. The proposed scheme consists of three successive steps: namely, multiresolution decomposition, hierarchical interpolation and predictive coding using two-dimensional multiplicative autoregressive models. The performance of the proposed technique is compared with three alternative techniques: namely, difference pyramid (DP), reduced difference pyramid (RDP) and hierarchical interpolation (HINT) method. The experimental results indicate that the proposed scheme achieves significantly higher compression compared to the other techniques considered. >
Room-temperature oxidation of ultrathin TiB 2 films

Titanium diboride has been claimed as a very promising candidate material for protective applications in the magnetic recording. Its oxidation resistance at room temperature is a critical criterion in assessing this application potential. In this paper, the oxidation characteristics of ultrathin TiB2 thin films, such as overcoat erosion and oxide thickness, are investigated via a combination of x-ray reflectivity, x-ray photoelectron spectroscopy (XPS), and atomic force microscopy. It was found that a <2-h exposure to air at room temperature led to the formation of approximately 15-A-thick, well-defined oxides at the expense of an approximately 9-A erosion of the TiB2 overcoats, coupled with the existence of a sharp oxide/TiB2 interface. XPS studies confirmed the existence of the oxides. Considering the decreasing allowable thickness for such protective overcoats, oxidation and the resultant thickness gain negate such a potential of ultrathin TiB2 films. The results in our current report provide a new perspective on its potential as protective overcoats in magnetic recording.
The dielectric behavior of polycrystalline ferroelectric films with fiber textures

We consider the effects of crystallographic symmetry, texture, and internal strain on the dielectric properties of polycrystalline ferroelectric thin films with fiber textures, including spontaneous polarization, coercivity, dielectric constant, dielectric tunability, and strain-induced phase transition, by combining Landau–Ginzburg–Devonshire phenomenological theory for ferroelectrics with the micromechanics theory for polycrystalline thin films. Cubic and tetragonal BaxSr1� xTiO3 (BST) films with [0 0 1] fiber texture, and cubic and rhombohedral BST films with [1 1 1] texture are considered. The results show that for [0 0 1]-textured film compressive strain enhances the spontaneous polarization, coercivity, and tunability while it decreases the dielectric constant; for [1 1 1]-textured film the effects are the opposite. It is also noted that [1 1 1]-textured films are less sensitive to internal strain than [0 0 1]-textured films. Good agreement with experimental data is also observed.
Candidate Support in Presidential Nomination Campaigns: The Case of Iowa in 1984

We analyze three explanations of candidate choice in presidential nomination campaigns: (1) a preference model, which contends that nomination choice is based on the ideological, issue, or candidate preferences of the voter; (2) a candidate-chances explanation that argues choice is motivated by the chances candidates have of winning the nomination or the general election; and (3) an expected utility model that includes both preferences and candidate chances by discounting ideological, issue, and candidate-trait preferences by the perceived chances each candidate has of winning in November. We test these explanations on samples of Democratic caucus attenders and state convention delegates from Iowa in 1984. The expected utility model most successfully predicts candidate choice in both samples. Even with appropriate controls for candidate affect, both preference and candidate chances measures have significant independent effects on candidate choice. Our analysis suggests that the interests of individual nom...
Microtiter enzyme-linked immunosorbent assay for immunoglobulin g cholera antitoxin in humans: sensitivity and specificity.

Serum samples were obtained from 92 informed, community volunteers before and 10, 21, and 28 days after they ingested 103 to 106Vibrio cholerae of Inaba or Ogawa serotype and classical or El Tor biotype as part of a cholera vaccine development program. Pre- and postchallenge sera were examined for neutralizing antibody to cholera toxin by the rabbit skin permeability factor and adrenal cell techniques. Immunoglobulin G-binding antibodies to cholera toxin were quantitated by enzyme-linked immunosorbent assay (ELISA) in serum diluted 1:200. The results obtained in these cholera volunteers were compared with a negative control population comprising 30 people who ingested enteropathogenic Escherichia coli or E. coli which produced heat-stable but not heat-labile enterotoxin. Although all three antitoxin assays correlated closely with each other in both groups of volunteers, ELISA was more sensitive than either neutralization assay in detecting both subclinical and overt cholera infections. Seroconversion was demonstrated by ELISA in 58 of 66 (88%) volunteers who excreted V. cholerae, including 50 of 54 (93%) with clinical cholera, compared with 47 of 66 (71%) and 52 of 66 (79%) by the rabbit skin permeability factor and adrenal cell techniques, respectively. Although ELISA does not measure the toxin-neutralizing activity of antibodies directly, it provides a practical alternative to the rabbit skin permeability factor and adrenal cell assays.
Effect of a Limited Time Feeding System on Reproductive Performance of Heavy Breed Pullets

Abstract SEVERAL methods of restricting body weight gains of heavy breed pullets and hens have been reported. Total feed-intake has been limited by feeding a measured amount or by limiting the time feed is available. Other systems have been used in which the level of energy, protein, or an amino acid has been lowered to reduce body weight gains and delay sexual maturity even though pullets consume feed ad libitum. Sexual maturity has been delayed by restricting pullets to 77% of ad libitum intake (Howes and Cottier, 1965). Smaller delays in sexual maturity were obtained by feeding low protein diets in comparison with feed restriction. Waldroup et al. (1966) concluded that body weight gain could be reduced during both the growing and laying periods by reducing the protein level without adversely affecting performance factors. Singsen et al. (1958) restricted feed intake of laying hens to 78% of ad libitum without affecting…
Functional localization of the nitric oxide/cGMP pathway in the salamander retina.

Nitric oxide (NO) is a gaseous neuromodulator that has physiological functions in every cell type in the retina. Evidence indicates that NO often plays a role in the processing of visual information in the retina through the second messenger cyclic guanosine monophosphate (cGMP). Despite numerous structural and functional studies of this signaling pathway in the retina, none have examined many of the elements of this pathway within a single study in a single species. In this study, the NO/cGMP pathway was localized to specific regions and cell types within the inner and outer retina. We have immunocytochemically localized nitric oxide synthase, the enzyme that produces NO, in photoreceptor ellipsoids, four distinct classes of amacrine cells, Muller and bipolar cells, somata in the ganglion cell layer, as well as in processes within both plexiform layers. Additionally, we localized NO production in specific cell types using the NO-sensitive dye diaminofluorescein. cGMP immunocytochemistry was used to functionally localize soluble guanylate cyclase that was activated by an NO donor in select amacrine and bipolar cell classes. Analysis of cGMP and its downstream target, cGMP-dependent protein kinase II (PKGII), showed colocalization within processes in the outer retina as well as in somata in the inner retina. The results of this study showed that the NO/cGMP signaling pathway was functional and its components were widely distributed throughout specific cell types in the outer and inner salamander retina.
Physically-aware N-detect test pattern selection

N-detect test has been shown to have a higher likelihood for detecting defects. However, traditional definitions of N-detect test do not necessarily exploit the localized characteristics of defects. In physically-aware N-detect test, the objective is to ensure that the N tests establish N different logical states on the signal lines that are in the physical neighborhood surrounding the targeted fault site. We present a test selection procedure for creating a physically- aware N-detect test set that satisfies a user-provided constraint on test-set size. Results produced for an industrial test chip demonstrate the effectiveness and practicability of our pattern selection approach. Specifically, we show that we can virtually detect the same number of faults 10 or more times as a traditional 10-detect test set and increase the number of neighborhood states and the number of faults with 10 or more states by 18.0 and 4.7%, respectively, without increasing the number of tests over a traditional 10-detect test set.
Dose optimization with computer-controlled gantry rotation, collimator motion and dose-rate variation

The applications of a computer-controlled radiation therapy system to optimize dose distributions in two dimensions are explored. This study is limited to a target volume with constant cross-section along an axis parallel to the long axis of the patient. The machine components that are continuously varied during treatment are the dose rate, the gantry angle, and the four independent collimator jaws, two of which can cross the beam centerline. Basic control strategies, treatment planning and delivery techniques are illustrated with clinical examples. We conclude that the computer-controlled radiation therapy system can easily and reliably deliver dose distributions which are significantly better than those produced by conventional multiple-field techniques.
Water soluble polymers: 70. Effects of methylene versus propylene spacers in the pH and electrolyte responsiveness of zwitterionic copolymers incorporating carboxybetaine monomers

Abstract Water soluble polyzwitterions have been synthesized by free radical copolymerization of acrylamide with the novel carboxybetaine monomer, 2-(2-acrylamido-2-methylpropyldimethylammonio) ethanoate (AMPDAE). Feed ratios of 10 to 100 mol% AMPDAE were employed to give the polyzwitterion series, DAEAM. Copolymer compositions of low conversion samples were determined from 13 C n.m.r. by integration of the carbonyl resonances. Reactivity ratios were determined yielding an r 1 r 2 value of 0.6. Molecular weights range from 6.3 to 10.4 × 10 6 g mol −1 as determined by low angle laser light scattering. Dilute solution properties of the copolymers have been studied as a function of added electrolytes and pH. Intrinsic viscosity behaviour in NaCl solutions is dependent on the mol% of AMPDAE incorporated into the copolymers. Reduced viscosities were also examined as a function of the nature of added electrolytes, displaying higher viscosity values in accord with the Hoffmiester lyotropic series. The copolymers exhibit an enhancement in viscosity as pH is lowered due to protonation of the carboxylate groups which renders the polymer coil cationic due to the presence of quaternary ammonium groups. The solution behaviour of the copolymer containing 25 mol% AMPDAE, which possesses one methylene unit between the quaternary ammonium group and the carboxylate group, is compared to that of a copolymer containing 25 mol% 4-(2-acrylamido-2-methylpropyldimethylammonio) butanoate, which possesses three methylene units between the charged centres.
The effect of hyperthermia on the early and late appearing mouse foot reactions and on the radiation carcinogenesis: Effect on the early and late appearing reactions

Abstract The effect of hyperthermia on radiation-induced early- and late-appearing foot reactions was studied in C3Hf/Sed mice derived from our defined flora mouse colony. The animal foot was irradiated with 137 Cs gamma-rays under hypoxic, air, or hyperbaric oxygen (O 2 30 psi) conditions. Hyperthermia of 43.5°C for 45 min was given locally in a water bath where a constant temperature ± 0.1°C was maintained. Treatment intervals between the 2 treatments were 20 min and 2 days. For the early-appearing reactions scores taken between the 14th and 35th post-irradiation days were averaged. Late-appearing reactions became apparent after approximately the 200th post-treatment day and increased with time. The foot reaction was enhanced by hyperthermia given 20 min before or after irradiation. Dose response curves for radiation given 20 min after hyperthermia for acute-appearing reactions lacked shoulders, whereas those following the same treatment schedule for late-appearing reactions showed significant shoulders. The thermal enhancement ratios (TER) for score 2.0 (complete epilation) early- and late-appearing reactions depended on the treatment interval and sequence. The TER values were greater for a short treatment interval (20 min.) than for a long treatment interval (2 days). Thermal enhancement was greater for hyperthermia given before irradiation compared to the reverse sequence. The TER values were always smaller for the late-appearing reactions than for the acute-appearing reactions. The relationships between early reaction scores and late reaction scores showed that the late reactions following combined heat and radiation are less extensive than those following radiation alone if they were compared at radiation doses which induced an equal level of early reactions. This difference was most significant at low early reaction scores and decreased with increasing score level.
Personal and relationship challenges of adults with type 1 diabetes: a qualitative focus group study.

OBJECTIVE Little is known about the psychosocial challenges of adults living with type 1 diabetes or its impact on partner relationships. This qualitative study was undertaken to gain better understanding of these issues. RESEARCH DESIGN AND METHODS Four focus groups were held, two with adult type 1 diabetic patients ( n = 16) and two with partners ( n = 14). Two broad questions were posed: “What are the emotional and interpersonal challenges you have experienced because you have (your partner has) type 1 diabetes?” and “How does the fact that you have (your partner has) type 1 diabetes affect your relationship with your partner, positively and/or negatively?” Sessions were recorded and transcribed, and analyzed by a team of four researchers, using constant comparative methods to identify core domains and concepts. RESULTS Four main domains were identified: 1 ) impact of diabetes on the relationship, including level of partner involvement, emotional impact of diabetes on the relationship, and concerns about child-rearing; 2 ) understanding the impact of hypoglycemia; 3 ) stress of potential complications; and 4 ) benefits of technology. Themes suggest that, although partner involvement varies (very little to significant), there exists significant anxiety about hypoglycemia and future complications and sources of conflict that may increase relationship stress. Partner support is highly valued, and technology has a positive influence. CONCLUSIONS Adults with type 1 diabetes face unique emotional and interpersonal challenges. Future research should focus on gaining a better understanding of how they cope and the effect of psychosocial stressors and coping on adherence, quality of life, and glycemic control.
Carbon‐13 NMR spectra of some chlorinated polycyclodiene pesticides

Carbon-13 NMR spectra have been obtained for aldrin, dieldrin, isodrin, endrin, heptachlor, heptachlor oxide and 24 of their degradation/conversion products. Chemical shifts were assigned on the basis of (1) comparison among the spectra, (2) single frequency, off-resonance decoupling experiments, (3) substituent effects derived for norbornanes and (4) spectra obtained with an added lanthanide shift reagent. The substituent effects previously reported for norbornanes were found to be applicable for establishing trends in the chemical shifts for many of the compounds studied.
Risk for metabolic control problems in minority youth with diabetes.

OBJECTIVE: We examined and quantified the degree of risk for poor glycemic control and hospitalizations for diabetic ketoacidosis (DKA) among black, Hispanic, and white children and adolescents with diabetes. RESEARCH DESIGN AND METHODS: We examined ethnic differences in metabolic control among 68 black, 145 Hispanic, and 44 white children and adolescents with type 1 diabetes (mean age 12.9 [range 1-21] years), who were primarily of low socioeconomic status. Clinical and demographic data were obtained by medical chart review. Glycohemoglobins were standardized and compared across ethnic groups. Odds ratios among the ethnic groups for poor glycemic control and hospitalizations for DKA were also calculated. RESULTS: The ethnic groups were not different with respect to age, BMI, insulin dose, or hospitalizations for DKA, but black children were older at the time of diagnosis than Hispanics (P
Dear Professor: The Influence of Recipient Sex and Status on Personalization and Politeness in E-Mail:

Although previous research has demonstrated a number of factors that affect the linguistic style of e-mails (e.g., sex of the sender and recipient), the present study emphasized the important role of recipient status on the personalization and politeness of educational e-mails. A total of 66 female undergraduates were asked to compose e-mails to a male or female peer or professor requesting study help for an upcoming exam. Results showed that participants wrote significantly more personalized and polite e-mails to peers, although e-mails to professors displayed significantly more written complexity.
Managing communication in integrated modular architectures

Summary form only given. Safety-critical real-time systems are being designed using off-the-shelf components connected together to provide the different functions expected from the system. In such architectures, the communication backbone plays an important role in helping systems meet their timing constraints. Components are typically connected via buses, and often components are connected to more than one bus. We describe an approach to synthesizing routes such that all messages meet their deadlines in distributed systems built using bus-based networks when the traffic characteristics are known in advance. This work is the starting point for further work, which will allow network resources to be allocated dynamically when traffic patterns cannot be determined at design-time.
Selective potentiation of paclitaxel (taxol)-induced cell death by mitogen-activated protein kinase kinase inhibition in human cancer cell lines.

Activation of the mitogen-activated protein kinase (MAPK) pathway in HeLa and Chinese hamster ovary cells after treatment with paclitaxel (Taxol) and other microtubule interacting agents has been investigated. Using a trans-reporting system, the phosphorylation of the nuclear transcription factors Elk-1 and c-jun was measured. Concentration- and time-dependent activation of the Elk-1 pathway, mediated primarily by the extracellular signal-regulated kinase (ERK) component of the MAPK family, was observed. Inactive drug analogs and other cytotoxic compounds that do not target microtubules failed to induce similar levels of activation, thereby indicating that an interaction between these drugs and the microtubule is essential for the activation of MAPKs. Evaluation of the endogenous levels of MAPK expression revealed cell-dependent expression of the ERK, c-jun N-terminal kinase, and p38 pathways. In the case of HeLa cells, time-dependent activation of ERK coincided with increased poly(ADP-ribose) polymerase (PARP) cleavage, phosphatidylserine externalization, and increased accumulation of cells in G2M. In both cell lines, inhibition of ERK activity potentiated paclitaxel-induced PARP cleavage and phosphatidylserine externalization, suggesting that ERK activity coincided with, but did not mediate, the cytotoxic effects of paclitaxel. We evaluated the nature of the interaction between paclitaxel and the MAPK kinase inhibitor U0126 in three cell lines, on the basis of a potential chemotherapeutic advantage of paclitaxel plus ERK inhibition. Our data confirmed additivity in those cells lines that undergo paclitaxel-induced ERK activation, and antagonism in cells with low ERK activity, suggesting that in tumors with high ERK activity, there may be an application for this strategy in therapy.
Compartmentation Analysis of Paraquat Fluxes in Maize Roots as a Means of Estimating the Rate of Vacuolar Accumulation and Translocation to Shoots.

Efflux analysis conducted after five loading periods of various lengths (2, 6, 12, 18, or 24 h) was used to investigate uptake, compartmentation, and translocation of [14C]paraquat in maize (Zea mays L.) seedlings. The time course for net paraquat uptake (paraquat concentration in uptake solution = 25[mu]M) into maize roots was linear (56.7 nmol g-1 root fresh weight h-1) for 24 h. Estimates of changes in paraquat content in the vacuole, cytoplasm, and cell wall after 2-, 6-, 12-, 18-, and 24-h loading periods indicated that the cell wall saturated rapidly, whereas accumulation of paraquat into the vacuole increased linearly (12.4 nmol g-1 root fresh weight h-1) over 24 h. In contrast to vacuolar accumulation, cytoplasmic paraquat content appeared to approach saturation. The half-time for paraquat efflux from the cell wall (16.6 min [plus or minus] 1.2 SD) and cytoplasm (58.8 min [plus or minus] 8.9 SD remained relatively constant regardless of the length of the loading period, whereas the half-time for efflux from the vacuole was considerably longer and increased linearly with increased loading time (6.1–18.7 h). The time course for paraquat translocation to the shoot was linear within a 24-h exposure to radiolabeled herbicide, but translocation did not begin until 5 h after initiation of treatment. The experimental approach used in these experiments provides a valuable method for examining the movement of paraquat in maize seedlings. Results indicate that the herbicide slowly accumulates in the vacuole of root cells but is also translocated to the shoot.
Chemical basis of ion transport specificity in biological membranes

This review addresses the issues of the chemical and physical processes whereby inorganic anions and cations are selectively retained by or passed through cell membranes. The channel and carrier mechanisms of membranes permeation are treated by means of model systems. The models are: the planar lipid bilayer for the cell membrane, Gramicidin for the channel mechanism, and Valinomycin for the carrier mechanism.
The Harmonic Oscillator

As an extended example of Newtonian dynamics, let us examine the motion of a particle under the influence of a force whose magnitude is proportional to the displacement of the particle from an equilibrium position, and whose direction is toward that equilibrium position. If we choose the coordinate system so that the origin is at the point of equilibrium, the force may be written $${\rm{F = - kr,}}$$ (4.1) where k is a positive constant. This linear restoring force is often referred to as a Hooke’s law force, after Robert Hooke, who first observed that the deformation of a solid (such as the stretch of a spring or the bending of a bar) is resisted by a force whose magnitude is approximately proportional to the deformation, as long as the deformation is not so large as to exceed the elastic limit. It is one of the most important forces in the study of physics because it provides a good approximation to many real physical systems and because its equations of motion in both classical and quantum mechanics have analytic solutions.
Schrödinger’s cat

We show that the classical framework of probability spaces, which does not admit a model-theoretical treatment, is equivalent to that of probability algebras, which does. We prove that the category of probability algebras is a stable cat, where non-dividing coincides with the ordinary notion of independence used in probability theory.
Quantifying the signals contained in heterogeneous neural responses and determining their relationships with task performance

The responses of high-level neurons tend to be mixtures of many different types of signals. While this diversity is thought to allow for flexible neural processing, it presents a challenge for unde...
Specific inhibition of rat brain phospholipase D by lysophospholipids.

Although the importance of phospholipase D (PLD) in signal transduction in mammalian cells is well documented, the negative regulation of PLD is poorly un- derstood. This is primarily due to a lack of known specific inhibitors of PLD. We herein report that the activity of par- tially purified rat brain PLD is inhibited by certain lysophos- pholipids, such as lysophosphatidylinositol, lysophosphati- dylglycerol, and lysophosphatidylserine in a highly specific manner. Inhibition of PLD by lysophospholipids was dose- dependent: the concentration of lysophosphatidylinositol required for half-maximal inhibition was about 3 m m . An analysis of the enzyme-kinetics suggested that lysophospho- lipids act as non-competitive inhibitors of PLD activity. As expected, PLD activity was stimulated by ADP-ribosylation factor (Arf) and phosphatidylinositol 4,5-bisphosphate (PIP 2 ). The inhibition of PLD by lysophospholipids, however, was not affected by the presence or absence of Arf or by an in- crease in PIP 2 concentration. A protein-binding assay sug- gested that lysophospholipids bind directly to PLD. These results indicate that the observed inhibition of PLD by lysophospholipids is due to their direct interaction rather than to an interaction between lysophospholipids and either Arf or PIP 2 . The present study suggests that certain lyso- phospholipids are specific inhibitors of rat brain PLD in a cell-free system and may provide the new opportunities to investigate mechanisms by which PLD is regulated by lyso- phospholipids, presumably liberated by phospholipase A 2 activation, in mammalian cells. —Ryu, S. B. and J. P. Palta. Specific inhibition of rat brain phospholipase D by lyso- phospholipids. J. Lipid Res. 2000. 41: 940-944.
Anti-oestrophilin antibodies as probes for receptor structure and function

The original discovery of steroid hormone receptors (Glascock and Hoekstra, 1959; Jensen and Jacobson, 1960) and essentially all our understanding of hormone-receptor interaction in responsive tissues (Jensen and DeSombre, 1973; Gorski and Gannon, 1976; O’Malley and Schrader, 1976) have depended on experiments in which a radiolabeled hormone serves as a marker for the receptor protein to which it binds. This ligand-binding approach has proved useful in detecting and measuring receptor substances as well as for following the receptor through purification procedures or during its biochemical interaction within the target cell. But despite the wealth of information they have furnished during the past 20 years, ligand-binding procedures suffer from certain limitations. Although strong, the association of hormone with receptor is non-covalent, so the bound steroid is subject to displacement during experimental manipulation of receptor preparations. Furthermore, the receptor proteins are labile substances that irreversibly lose their ability to bind hormone by partial denaturation or by the action of factors present in extracts of many tissues and tumours. Unless some kind of exchange assay is carried out, which usually requires warming, the labelled steroid fails to detect receptor that is already occupied by endogenous hormone. It may also fail to recognise receptor in its early stages of synthesis before it has acquired the ability to bind hormone or in the later stages of its action where the steroid and receptor may have parted company.
Paleoenvironmental Change in Central Texas: The Palynological Evidence

Analysis of pollen spectra from Boriack and Weakly bogs provides a 16,000 year sequence for central Texas. Fluctuations between grass and arboreal pollen indicate that numerous shifts between fores...
Behavioral and Neurologic Assessment: Using the National Institutes of Health Toolbox

Cognition, psychological well-being, stress, functional status, and pain are all priority outcomes of interest to oncology nurses. However, it can be challenging to choose an instrument for clinical assessment or for use in research projects that assess these constructs. The National Institutes of Health Toolbox for Assessment of Neurological and Behavioral Function was created for measuring emotional health and cognitive, motor, and sensory function. The toolbox can be a potentially useful resource for clinicians and nurse researchers.
Ignorance and Economics

AbstractIgnorance—or the limits in our knowledge, is a major issue in economics. This paper argues that economic policy should be treated as an art and craft, much as engineers do in their own field, and not as a science. This in turn leads to a number of simple rules that could guide methodology in our field, such as understanding our work as that of problem solvers, not truth seekers, and recognizing the ad hoc nature of our models and other heuristics. We would also be well advised to add a fudge factor to our policy recommendations and be more creative in thinking about policy.