cssi/SciSciGPT-SciSciNet huggingface dataset:
Current management of anemia in adult hemodialysis patients with end-stage renal disease.

The management of anemia in adult end-stage renal disease (ESRD) patients receiving hemodialysis in dialysis facilities is examined. Clinical information was collected for a random sample of adult (age > or = 18 years) patients who received hemodialysis for ESRD between October and December 1999 and included hemoglobin concentrations, epoetin alfa doses and routes of administration, iron prescribing patterns, transferrin saturation levels, and serum ferritin concentrations. Patients whose data did not include hemoglobin concentrations with the weekly epoetin dose were excluded from the analysis. Associations by patient characteristics and geographic region were examined for clinical intermediate outcomes and epoetin alfa and iron prescribing practice patterns. Data were submitted for 8154 patients, and hemoglobin values linked to weekly epoetin alfa doses were available for 7573 of those patients. The mean hemoglobin concentration for patients in the sample was 11.4 +/- 1.3 g/dL. Sixty-seven percent of patients had mean hemoglobin values > or = 11 g/dL. Females, blacks, patients 18-44 years old, and patients receiving hemodialysis for less than six months exhibited significantly lower mean hemoglobin values despite being prescribed, on average, significantly higher epoetin alfa doses than males, whites, older patients, and patients receiving hemodialysis for six months or more (p 11 g/dL and certain patient characteristics, including white race, hemodialysis for six months or longer, lower prescribed weekly epoetin alfa doses, prescription of i.v. iron, mean transferrin saturation levels > or = 20%, mean Kt/V > or = 1.2, and higher mean serum albumin values. Prescribing patterns for i.v. iron did not vary by the status of patients' iron stores. Regional and patient-specific variations in parameters of anemia management provide pharmacists with the opportunity to contribute to a multidisciplinary team approach to improve the care of hemodialysis patients.
Measuring Intra‐Cultural Bimodality and Cross‐Cultural Diversity in American‐Japanese Business Negotiations

One of the greatest challenges facing managers and administrators in an international environment is effectively communicating and negotiating with their foreign counterparts. Yet, a main portion of their time is spent in these most critical activities. Much has been written about the differences in the perception, motivation and behavior of people from different cultures, especially about the American and Japanese interface. However, very little scientific confirmation and measurements exist. In this empirical study the nature and intensity of cross‐cultural similarities and dissimilarities have been tested and measured with selected statements on a Likert‐type scale on a sample of 41 American and 29 Japanese practicing managers pointing to weak intra‐cultural bimodality, but strong cross‐cultural contrasts.
Tracing immigrant identity through the plate and the palate

This article brings together scholarship on foodways and identity with discourses of sustainable and local food to illuminate the food practices of Latino/a immigrants living in Seattle, WA. Drawing upon 4 years of ethnographic research, this article argues that migration and placemaking impact the maintenance of culturally meaningful foodways and that reclaiming and reshaping one's foodways plays a central role in both longing for home and building new lives in the United States. Through describing how Latino/a foodways often parallel, yet remain marginal to, the values and priorities of the movements for sustainable and local food, I make the case for more inclusive food movement advocacy.
Crustal Structure of the Northern Mississippi Embayment and a Comparison with other Continental Rift Zones

Abstract Previous geological and geophysical investigations have suggested that the Mississippi Embayment is the site of a Late Precambrian continental rift that was reactivated in the Mesozoic. New information on the deep structure of the northern Mississippi Embayment, gained through an extensive seismic refraction survey, supports a rifting hypothesis. The data indicate that the crust of the Mississippi Embayment may be characterized by six primary layers that correspond geologically to unconsolidated Mesozoic and Tertiary sediments (1.8 km/s), Paleozoic carbonate and clastic sedimentary rocks (5.9 km/s), a low-velocity layer of Early Paleozoic sediments (4.9 km/s), crystalline upper crust (6.2 km/s), lower crust (6.6 km/s), modified lower crust (7.3 km/s), and mantle. Average crustal thickness is approximately 41 km. The presence and configuration of the low-velocity layer provide new evidence for rifting in the Mississippi Embayment. The layer lies within the northeast-trending upper-crustal graben reported by Kane et al. (1981), and probably represents marine shales deposited in the graben after rifting. The confirmation and delineation of a 7.3 km/s layer, identified in previous studies, implies that the lower crust has been altered by injection of mantle material. Our results indicate that this layer reaches a maximum thickness in the north-central Embayment and thins gradually to the southeast and northwest, and more rapidly to the southwest along the axis of the graben. The apparent doming of the 7.3 km/s layer in the north-central Embayment suggests that rifting may be the result of a triple junction located in the Reelfoot Basin area. The crustal structure of the Mississippi Embayment is compared to other continental rifts: the Rhinegraben, Limagnegraben, Rio Grande Rift, Gregory Rift, and the Salton Trough. This comparison suggests that alteration of the lower crust is a ubiquitous feature of continental rifts.
Digit serial multipliers

Abstract Digit serial data transmission can be used to an advantage in the design of special purpose processors where communication issues dominate and where digit pipelining can be used to maintain high data rates. VLSI signal processing is one such problem domain. We propose detailed designs of unidirectional systolic and semisystolic programmable digit pipelined (serial) multipliers. These multipliers are programmable; i.e., one operand is prestored in the multiplier and the other operand is fed in a digit serial fashion. The VLSI implementation of the systolic multiplier is given. This systolic multiplier is used in our VLSI signal processing system. Lastly, for the sake of completeness we also propose designs of nonprogrammable unidirectional and bidirectional digit serial multipliers.
Theoretical Articulation on Immigration and Crime

This article reviews the contributions of social disorganization, cultural, and strain perspectives to criminological understanding of the relationship between immigration and crime. In efforts to draw parallels between the theories and strands of scholarship on immigration, various hypotheses are outlined to encourage expansion of knowledge on immigration and crime, theoretical extension, revision, and perhaps integration as well.
Reduction of aliasing in modulation transfer function measurements

The images formed by many radiological systems are difficult to sample at spatial intervals small enough to avoid aliasing in the calculation of the system's modulation transfer function. However, if a system's response can be assumed to be symmetrical, this assumption can be used to effectively double the sampling density and to double the frequency limit before aliasing occurs. To accomplish this, a more complex algorithm is required. In this work, the formula for the calculation of the modulation transfer function from a symmetrical, one-dimensional line spread function is derived and a similar result for a symmetrical, two-dimensional point spread function is presented. The effect of noisy data and errors in the estimation of the offset of the center of the line spread function from a sampling point are investigated by simulation studies. For low noise (relative standard deviation of 1%) and an offset error of no more than 2% or 3% of a sampling interval, reasonable precision is obtained. These conditions appear to be achievable, especially when the noise is Poisson distributed.
PROPERTIES OF ADENOSINE DEAMINASE FROM CANDIDA ALBICANS

Adenosine deaminase (ADA; adenosine aminohydrolase, E.C. 3.5.4.4), a purine catabolic enzyme, was studied in Candida albicans, an opportunistic yeast that causes diseases ranging from superficial infections to the deep systemic disease, candidiasis, in immunosuppressed humans. The fungus was grown as a yeast form in LEE's synthetic medium, pH 4.5, at room temperature for various growth periods. Adenosine deaminase (ADA) activity was determined from the cell free extract by measuring the change in absorbance 265 nm resulting from the deamination of adenosine. In yeast form, maximum growth and ADA activity were found at 72 and 24 hours, respectively, whereas in the mycelial form both the growth and ADA activity were maximum after 48 hours. Among the three media tested, tryptic soy broth supported maximum growth and enzyme production, compared to LEE synthetic medium or SABOURAUD dextrose broth. The enzyme was active over the pH range 4-8 and the optimum temperature for ADA activity was found to be 37 degrees C.
Some characterizations of discrete distributions by properties of their moment distributions

The moment distributions of a nonnegative random variable are defined and their applications in life length studies are indicated. Some properties of the moment distributions are employed to characterize the discrete distributions in the class of modified power series distributions introduced by the author (1974). In particular, characterisations of Poisson, binomial and negative binomial distributions are obtained.
The activation of unrelated and canceled intentions.

Theintention superiority effect is the finding that intentions to perform an activity are stored in a heightened state of activation. The effect has also been generalized to the finding that once an intention is fulfilled, it is inhibited relative to more neutral material about which no intentionality has been formed. In two experiments, we tested some ecological and naturally occurring situations taken from the literature on prospective memory and demonstrated that they have consistent consequences for the activation level of an intention. In Experiment 1, a constellation of unrelated activities displayed heightened activation prior to completion and displayed inhibition after completion. In Experiment 2, canceling the intention resulted in inhibition just as completing the intention does in this paradigm. The results are discussed in terms of their practical and theoretical importance to theories of prospective memory.
Effects of plating parameters on the Ni–P–Al2O3 composite coatings prepared by pulse and direct current plating

Abstract In this study, Al 2 O 3 nanoparticles were incorporated into Ni–P alloy matrix by pulse current (PC) and direct current (DC) plating. The effects of bath composition and operating conditions of electrodeposited Ni–P–Al 2 O 3 composite coatings were studied, and the micro-hardness of the deposits was determined. The results showed that with increasing current density as well as Al 2 O 3 content in the bath for DC plating, the embedding volume percentage of Al 2 O 3 of coating increased and the phosphorus content decreased. The incorporation percentage of Al 2 O 3 particles in the composite coatings prepared by PC plating was significantly affected by pulse plating parameters such as average current density, duty cycle and frequency as well as the bath composition. It is also found that PC plating leads to higher embedding percentages and more homogeneous distribution of Al 2 O 3 particles in the Ni–P matrices compared with deposits prepared under DC conditions. The incorporation percentage of Al 2 O 3 particles in PC plated composite coatings increased when high duty cycles and high frequencies were used. The hardness of the composite coatings deposited with a pulse current increased as the duty cycle increases from 0.2 to 0.7.
La voz fronteriza: Óscar Monroy Rivera and the Corrido Tradition along the US-Mexico Border

By examining Joaquin Murrieta in Sonoran literature and his unique appearance in the work of Oscar Monroy Rivera, this paper seeks to demonstrate how his appearance may indicate a shift in the cultural discourse emanating from Sonora and the border during the critical period of the 1980s. His appearance reflects the desire on the part of the local communities at a time of social change and growth to engage in a dialogue concerning their collective identity, re-centering it on the geographical space of the border itself and material conditions there.
Food Insecurity, Depression, and Social Support in HIV-Infected Hispanic Individuals

Previous research has identified an association between food insecurity and depression in a variety of world regions in both healthy and HIV-infected individuals. We examined this association in 183 HIV-infected Hispanic adults from the greater Boston area. We measured depression with the Burnam depression screen and food insecurity with the Radimer/Cornell Questionnaire. Dietary intake was assessed with an adapted version of the Block Food Frequency Questionnaire. Logistic regression models were created with depression as the outcome variable and food insecurity as the main predictor. In bivariate analyses, food insecurity was significantly associated with depression [odds ratio (OR) 2.5; 95% confidence interval (CI) 1.1, 5.5; p = 0.03]. When we accounted for social support, food insecurity was no longer significant. We found no differences in the quality or quantity of dietary intake between the food insecure and food secure groups. Our findings highlight the importance of social support in the association between food insecurity and depression. Food insecurity may reflect social support more than actual dietary intake in this population.
The deteriorating status of African rhinos

Rhinos have given conservationists cause for concern for many decades, and there have been regular reports in Oryx of their deteriorating status in several countries. Now the authors, former Chairman and Executive Officer, respectively, of the IUCN/SSC African Elephant and Rhino Specialist Group, give an up-to-date account of rhinos in Africa, their numbers, distribution, and descriptions of areas where they are particularly vulnerable, as well as those where conservation action is having a positive effect.
The potential role of vehicle automation in reducing traffic-related energy and emissions

In the last few years, there has been a significant increase of interest related to vehicle automation, even though the fundamental building blocks for automating vehicles have been developed over the last several decades. In parallel, there has been a big push to make vehicles more energy efficient and less polluting, through the development of advanced powertrains, the development and promotion of alternative lower-carbon fuels, better managing vehicle miles traveled, and improving traffic operations. One of the key questions is how can vehicle automation contribute to energy efficiency and reducing emissions. In this paper, we outline some of these potential impacts, examining issues such as vehicle design, vehicle and traffic operations, and even potential changes in activity patterns.
Abstract LB-289: Synthetic Hsp90 inhibitor, PF-04928473 and prodrug PF-04929113, demonstrates potent antitumor activity in head and neck cancer by inhibiting multiple proliferative and prosurvival signaling pathways

Purpose: Heat shock protein 90 (Hsp90) is a molecular chaperone that stabilizes client substrates involved in cell proliferation, survival, and apoptosis. Cancer cells display increased dependency on Hsp90 and client oncoproteins, and Hsp90 has been identified as a druggable target. This study investigated the biological activity of a synthetic small molecule inhibitor of Hsp90, PF-04928473 and the orally available pro-drug PF-04929113 in head and neck squamous cell carcinoma (HNSCC). Experimental Design: Hsp90 expression was examined in nine human HNSCC cell lines (UMSCC). In vitro, the effect of PF-04928473 on cell proliferation, death and cell cycle were examined by MTT assay and flow cytometry. The effects on signaling molecules and cytokine production were determined using Western blot, reporter gene, and Luminex assays. In vitro combination with radiation was examined using the clonogenic survival assay. The effect of pro-drug PF-04929113 on UMSCC-11A tumor growth and Hsp90 client proteins were examined in the murine xenograft model and by immunohistochemistry (IHC). Results: UMSCC cell lines over-expressed Hsp90 mRNA and protein when compared with normal keratinocytes. In vitro, PF-04928473 potently inhibited UMSCC cell growth, induced cell death and modulated cell cycle, with an IC50 range of 32-73nmol/L. Combining radiation and PF-04928473 increased radiation sensitivity by a dose modifying effect of 1.4. PF-04928473 significantly modulated signaling molecules, including down-regulation of c-Met receptor, IKK, IKK, and BCLXL, as well as up-regulation of cleaved PARP, pro-apoptotic p53, PUMA, and p21 protein expression. The drug inhibited AKT, ERK, and STAT3 phosphorylation, suppressed NF- B, AP-1, BCLXL, and IL8 reporter activities, and blocked IL8, IL6, and VEGF production. In vivo, pro-drug PF-04929113 20mg/kg daily for 3-7 weeks significantly inhibited tumor growth. After treatment, tumor specimens showed increased IHC staining for p53, PUMA, and TUNEL, and decreased staining for c-Met, SRC, p-STAT3, p-AKT, p-ERK, IKK, RELB, Ki67 and CD31. Conclusion: Synthetic Hsp90 inhibitor PF-04928473 effectively modulated proliferation, cell survival, and inflammatory and angiogeneic cytokine production in HNSCC in vitro. Pro-drug PF-04929113 inhibits tumor growth in vivo by promoting apoptosis through inhibition of several key signaling pathways. [Supported by NIDCD project ZIA-DC-000073] Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-289.
Comparison of myosin and creatine kinase isoforms in left ventricles of young and senescent Fischer 344 rats after treatment with triiodothyronine.

Abstract The effects of perturbation of thyroid hormone levels on expression of myosin and creatine kinase isoforms were examined in maturing and senescent rats. Whereas LV of maturing rats contain only α-MHC, LV of senescent rats contain nearly equal mounts of both α-MHC and β-MHC. When maturing rats were made hypothyroid by treatment for 14 days with the antithyroid agent, propylthiouracil (PTU), β-MHC and β-MHC mRNA levels increased significantly. Administration of T3 to senescent rats, or maturing rats made hypothyroid by PTU treatment produced similar decreases in levels of both β-MHC and β-MHC mRNA. In contrast, treatment with T3 produced little change in creatine kinase isoform distribution. Thus, thyroid hormone appears to play a critical role in regulating expression of the isoforms of myosin but not of creatine kinase.
Impinging laminar jets at moderate Reynolds numbers and separation distances.

An experimental and numerical study of impinging, incompressible, axisymmetric, laminar jets is described, where the jet axis of symmetry is aligned normal to the wall. Particle streak velocimetry (PSV) is used to measure axial velocities along the centerline of the flow field. The jet-nozzle pressure drop is measured simultaneously and determines the Bernoulli velocity. The flow field is simulated numerically by an axisymmetric Navier-Stokes spectral-element code, an axisymmetric potential-flow model, and an axisymmetric one-dimensional stream-function approximation. The axisymmetric viscous and potential-flow simulations include the nozzle in the solution domain, allowing nozzle-wall proximity effects to be investigated. Scaling the centerline axial velocity by the Bernoulli velocity collapses the experimental velocity profiles onto a single curve that is independent of the nozzle-to-plate separation distance. Axisymmetric direct numerical simulations yield good agreement with experiment and confirm the velocity profile scaling. Potential-flow simulations reproduce the collapse of the data; however, viscous effects result in disagreement with experiment. Axisymmetric one-dimensional stream-function simulations can predict the flow in the stagnation region if the boundary conditions are correctly specified. The scaled axial velocity profiles are well characterized by an error function with one Reynolds-number-dependent parameter. Rescaling the wall-normal distance by the boundary-layer displacement-thickness-corrected diameter yields a collapse of the data onto a single curve that is independent of the Reynolds number. These scalings allow the specification of an analytical expression for the velocity profile of an impinging laminar jet over the Reynolds number range investigated of 200<=Re<=1400.
Monosynaptic inhibition of neck motoneurons by the medial vestibular nucleus.

Stimulation of the brain stem in cats anesthetized with pentobarbital evoked short-latency IPSPs in many neck motoneurons. From the segmental delay of these IPSPs, and from comparison of their latencies with those of monosynaptic EPSPs evoked in the same motoneuron population by stimulation of the brain stem, it is concluded that the IPSPs are monosynaptic and are produced by descending inhibitory fibers.
Feasibility of separations for distillation of nonideal ternary mixtures

The product compositions in single-feed distillation columns can be specified only in certain regions of the composition space, which depend only on the pressure, feed, and vapor-liquid equilibrium for the mixture. In nonideal mixtures, even without azeotropes, the regions may allow unusual product distributions. For example, the distillate in a direct split is composed primarily of the lightest component. Intuition and experience with relatively ideal mixtures suggest that the next most plentiful component is the intermediate boiler. In nonideal mixtures, however, with or without azeotropes, the next most plentiful component may be the highest-boiling species with only trace amounts of the intermediate boiler. For azeotropic mixtures, distillation boundaries may give rise to additional restrictions on the product compositions. The authors describe how simple distillation boundaries deform into continuous distillation boundaries and, in a limited number of cases, how the simple distillation boundaries can be crossed in continuous columns for certain ranges of the design variables. Unfortunately, such designs may be quite sensitive to model uncertainties or to disturbances in the parameters.
Robust stability and stabilization of uncertain delay systems

This paper considers the problem of robust stability and stabilization of uncertain time delay systems. We focus on the class of Metzlerian delay systems and use the interesting properties of Metzler matrix to provide the necessary ingredients for the main results of the paper. It is shown that Metzlerian delay system is asymptotically stable if and only if the Metzlerian system without delay∗ is asymptotically stable. This fact allows one to establish strong results on constrained stabilization for delay systems. The robust stability of Metzlerian delay system is also revisited and, without requiring long derivation, direct formulas for calculating the stability radius of this class of systems are provided. Finally, we consider the problem of constrained robust stabilization of interval delay systems and outline an LMI based solution for it. The paper concludes with two numerical examples to support the theoretical results.
The Response of Hardwood Flakes and Flakeboard to High Temperature Drying

Abstract This study assesses the effect of high temperature drying on chemical and mechanical properties of flakes and correlates changes in flake quality with board properties. The high temperature drying of flakes was found to have a significant effect on the internal bond (IB) of the resulting panels. The highest IB values were observed in boards produced from flakes dried at 150°C. Boards produced from flakes dried at 20°C and 350°C exhibited consistently lower values for IB. Opposite trends were noted for total acid content of flake. Multiple regression and correlation analysis revealed a strong relationship between IB, total acid content, and dryer temperature. A significant species effect was also present. Increased levels of flake total acids. acid buffering capacity, and the ratio of acid to base buffering capacities resulted in decreased board property values. Flake bending tests indicated that, in general, the strength and stiffness of the flakes were adversely affected by high temperature dryi...
Macrophage insulin receptor deficiency increases ER stress-induced apoptosis and necrotic core formation in advanced atherosclerotic lesions

Insulin resistance in diabetes and metabolic syndrome is thought to increase susceptibility to atherosclerotic cardiovascular disease, but the underlying mechanisms are poorly understood. To evaluate the possibility that decreased insulin signaling in macrophage foam cells might worsen atherosclerosis, Ldlr(-/-) mice were transplanted with insulin receptor Insr(+/+) or Insr(-/-) bone marrow. Western diet-fed Insr(-/-) recipients developed larger, more complex lesions with increased necrotic cores and increased numbers of apoptotic cells. Insr(-/-) macrophages showed diminished Akt phosphorylation and an augmented ER stress response, leading to induction of scavenger receptor A and increased apoptosis when challenged with cholesterol loading or nutrient deprivation. These studies suggest that defective insulin signaling and reduced Akt activity impair the ability of macrophages to deal with ER stress-induced apoptosis within atherosclerotic plaques.
Longitudinal predictors of progression of carotid atherosclerosis in rheumatoid arthritis.

Objective To explore predictors of change in measures of carotid atherosclerosis among rheumatoid arthritis (RA) patients without known cardiovascular disease (CVD) at baseline. Methods RA patients underwent carotid ultrasonography at 2 time points separated by a mean ± SD of 3.2 ± 0.3 years. The associations of baseline and average patient characteristics with the average yearly change in the mean maximal intima-media thickness (IMT) of the common carotid artery (CCA) and the internal carotid artery (ICAs) and with incident or progressive plaque in the ICA/carotid bulb, were explored. Results Among the 158 RA patients, the maximal CCA-IMT increased in 82% (median 16 μm/year; P < 0.001) and the maximal ICA-IMT increased in 70% (median 25 μm/year; P < 0.001). Incident plaque was observed in 14% of those without plaque at baseline (incidence rate 4.2 per 100 person-years [95% confidence interval 1.6, 6.8]). Plaque progression was observed in 5% of those with plaque at baseline. Among RA predictors, the adjusted average yearly change in the maximal CCA-IMT was significantly greater in patients with earlier RA than in those with disease of longer duration. Those taking tumor necrosis factor (TNF) inhibitors at baseline had a 37% lower adjusted rate of progression in the maximal CCA-IMT compared with nonusers (14 μm/year versus 22 μm/year; P = 0.026). For the maximal ICA-IMT, cumulative prednisone exposure was associated with progression after adjustment (1.2 μm/year per gm [95% confidence interval 0.1, 2.4]) and was lower in patients who were prescribed statins concomitant with prednisone. Higher swollen joint counts and higher average C-reactive protein levels were both associated with incident or progressive plaque, primarily in patients with elevated CVD risk at baseline based on the Framingham Risk Score. Conclusion These prospective data provide evidence that inflammation is a contributor to the progression of subclinical atherosclerosis in RA and that it is potentially modified favorably by TNF inhibitors and detrimentally by glucocorticoids.
An evaluation of fluorometric proteinase assays which employ fluorescamine

The sensitivity and utility of proteinase assays employing fluorescamine, a compound which reacts with primary amines to form a fluorescent adduct, was assessed. As little as 1 ng of purified trypsin or clostridiopeptidase A could be detected within 3 h of incubation at 37 degrees C, using casein or gelatin as substrates. Increasing the incubation period to 18 h permitted the detection of 250 pg of each enzyme. When gelled collagen was utilized as substrate, the sensitivity to clostridiopeptidase A was reduced to 2.5 ng at 3 h and 500 pg at 18 h. The techniques could be used to measure the gelatinase, caseinase, and collagenase activities of culture media conditioned by synovial tissue. The main disadvantage of this assay is its susceptibility to interference by compounds which fluoresce or quench. This, in turn, necessitates additional blanks, which may render the assay tedious.
The use of harmonics in 3-D magnetic fields

Motivated by the need for new means for specification and determination of 3-D fields that are produced by electromagnetic lens elements in the region interior to coil windings and seeking to obtain techniques that will be convenient for accurate conductor placement and dynamical study of particle motion, we have generalized the representation of a 2-D magnetic field to 3-D. We have shown that the 3-D magnetic field components of a multipole magnet in the curl-free divergence-free region near the axis r=0 can be derived from one dimensional functions A/sub n/(z) and their derivatives. >
The scatter focussing of multi-GeV charged particles and neutral hadrons

The multiple Coulomb scattering of charged particles and the nuclear elastic scattering of neutral hadrons may serve as a basis for the design of lenses for beams of such particles. The optical and spectral properties of such lenses are explored and numerical examples are given.
Micromechanics of isolated sickle cell hemoglobin fibers: bending moduli and persistence lengths.

Abstract Pathogenesis in sickle cell disease depends on polymerization of deoxyhemoglobin S into rod-like fibers, forming gels that rigidify red cells and obstruct the systemic microvasculature. Fiber structure, polymerization kinetics and equilibria are well characterized and intimately related to pathogenesis. However, data on gel rheology, the immediate cause of obstruction, are limited, and models for structure and rheology are lacking. The basis of gel rheology, micromechanics of individual fibers, has never been examined. Here, we isolate fibers by selective depolymerization of gels produced under photolytic deliganding of CO hemoglobin S. Using differential interference contrast (DIC) microscopy, we measure spontaneous, thermal fluctuations in fiber shape to obtain bending moduli (κ) and persistence lengths (λ p ). Some fibers being too stiff to decompose shape accurately into Fourier modes, we measure deviations of fiber midpoints from mean positions. Serial deviations, sufficiently separated to be independent, exhibit Gaussian distributions and provide mean-squared fluctuation amplitudes from which κ and λ p can be calculated. λ p ranges from 0.24 to 13 mm for the most flexible and stiffest fibers, respectively. This large range reflects formation of fiber bundles. If the most flexible are single fibers, then λ p =13 mm represents a bundle of seven single fibers. Preliminary data on the bending variations of frozen, hydrated single fibers of HbS obtained by electron microscopy indicate that the value 0.24 mm is consistent with the persistence length of single fibers. Young’s modulus is 0.10 GPa, less than for structural proteins but much larger than for extensible proteins. We consider how these results, used with models for cross-linking, may apply to macroscopic rheology of hemoglobin S gels. This new technique, combining isolation of hemoglobin S fibers and measurement of micromechanical properties based on thermal fluctuations and midpoint deviations, can be used to study fibers of mutants, hemoglobin A/S, and mixtures and hybrids of hemoglobin S.
Structure, mechanism and evolution of chloroplast transfer RNA processing systems.

Chloroplasts of land plants have an active transfer RNA processing system, consisting of an RNase P-like 5′ endonuclease, a 3′ endonuclease, and a tRNA:CCA nucleotidyltransferase. The specificity of these enzymes resembles more that of their eukaryotic counterparts than that of their cyanobacterial predecessors. Most strikingly, chloroplast RNase P activity almost certainly resides in a protein, rather than in an RNA protein complex as in Bacteria, Archaea, and Eukarya. The chloroplast enzyme may have evolved from a preexisting chloroplast NADP-binding protein. Chloroplast RNase P cleaves pre-tRNA by a reaction mechanism in which at least one of the Mg2+ ions utilized by the bacterial ribozyme RNase P is replaced by an amino acid side chain.
Finite element modeling of damage accumulation in trabecular bone under cyclic loading.

A two-dimensional finite element model of an idealized trabecular bone specimen was developed to study trabecular bone damage accumulation during cyclic compressive loading. The specimen was modeled as a two-dimensional honeycomb-like structure made up of an array of hexagonal cells. Each trabecula was modeled as a linearly elastic beam element with the same material properties as cortical bone. Initial microcracks were assumed to exist within the oblique trabeculae and to grow according to the Paris law. Forces and moments were computed in each trabecula and the microcracks were allowed to propagate until fracture occurred. Between cycles, fractured trabeculae were removed from the finite element mesh, and force and moment distributions were calculated for the next cycle. This iterative process was continued until the simulated trabecular bone specimen showed a 10% reduction in modulus. Creep failure was also studied using a single cell analysis, in which a closed-form solution was obtained after prescribing the creep properties of the trabeculae. The results of the crack propagation analysis showed that fractures of only a small number of individual trabeculae can cause a substantial reduction in the modulus of the trabecular bone specimen model. Statistical tests were performed to compare the slopes and intercepts of the S-N curves of our model predictions to those of experimentally derived S-N curves for bovine trabecular bone. There was no significant difference (p > 0.2 for both slope and intercept) between our model predictions and the experimentally derived S-N curves for the low-stress, high-cycle range. For the high-stress, low-cycle range, the crack propagation model overestimated the fatigue life for a given stress level (for slope, p 0.2). These findings suggest that the primary failure mechanism for low-stress, high-cycle fatigue of trabecular bone is crack growth and propagation, while the primary failure mechanism for high-stress, low-cycle fatigue is creep deformation and fracture. Furthermore, our results suggest that the modulus of trabecular bone at the specimen level may be highly sensitive to fractures of individual trabeculae.
Forms of Hydrogen and Hydrogen Diffusion in Realistic Models of a-Si:H

Using ab initio density functional calculations we investigate the energetics of hydrogen in a-Si:H starting from a basic supercell that contains 142 atoms and is completely free of defects. The study includes isolated H atoms bonded to dangling bonds, H atoms bonded to dangling bonds in regions of clustered H, bond centered hydrogen, and molecular hydrogen. In particular, the difference between clustered and isolated hydrogen has been largely ignored in the past. Energetics of doped as well as undoped cells are considered. The results are discussed with particular emphasis on H diffusion and the replacement of atoms in molecular hydrogen with those bonded.
Synchronized videostroboscopy and electroglottography

Summary A synchronized videostroboscopic/electroglottographic procedure was used to evaluate laryngeal physiology in 10 consecutive female patients referred to the University of Chicago Center for Speech and Swallowing Disorders. The results show that the technique provides a useful cross-validation function in the clinical analysis of videostroboscopic and electroglottographic data. When used as described, the procedure is technically simple to perform and valuable for documentation of results.
Why symbolic computation in robotics

Abstract This article is organized to demosttrate various applications of symbolic computation in robot manipulator design and analysis. Four major areas—kinematics, dynamics, trajectory planning and control, and pose error modeling—are extensively surveyed. A concept of an intermediate symbolic manipulator module is also described to automate and couple the processes of an interactive robot geometry design and numerical simulation.
Associations of Diabetes Mellitus, Insulin, Leptin, and Ghrelin With Gastroesophageal Reflux and Barrett's Esophagus

Background & Aims Insulin and leptin have proliferative and anti-apoptotic effects. Ghrelin promotes gastric emptying and secretion of growth hormone and inhibits inflammation. We assessed whether diabetes mellitus and serum levels of insulin, leptin, and ghrelin are associated with gastroesophageal reflux disease (GERD) and Barrett's esophagus. Methods We conducted a case-control study in 822 men undergoing colorectal cancer screening who were recruited to also undergo upper endoscopy. We identified 70 with Barrett's esophagus; 80 additional men with Barrett's esophagus were recruited shortly after their clinical diagnoses. Serum levels of insulin, leptin, and ghrelin were assayed in all 104 fasting men with Barrett's esophagus without diabetes and 271 without diabetes or Barrett's esophagus. Logistic regression was used to estimate the effects of diabetes and levels of insulin, leptin, and ghrelin on GERD and Barrett's esophagus. Results Among men with GERD, diabetes was inversely associated with Barrett's esophagus (adjusted odds ratio [OR] = 0.383; 95% confidence interval [CI]: 0.179−0.821). Among nondiabetics, hyperinsulinemia was positively associated with Barrett's esophagus, but the association was attenuated by adjustment for leptin and ghrelin. Leptin was positively associated with Barrett's esophagus, adjusting for obesity, GERD, and levels of insulin and ghrelin (OR for 3 rd vs 1 st tertile = 3.25; 95% CI: 1.29−8.17); this association was stronger in men with GERD ( P = .01 for OR heterogeneity). Ghrelin was positively associated with Barrett's esophagus (OR for an increment of 400 pg/mL = 1.39; 95% CI: 1.09−1.76), but inversely associated with GERD (OR for 3 rd vs 1 st tertile = 0.364; 95% CI: 0.195−0.680). Conclusions Based on a case-control study, leptin was associated with Barrett's esophagus, particularly in men with GERD. Serum insulin level was associated with Barrett's esophagus, but might be mediated by leptin. Serum ghrelin was inversely associated with GERD, as hypothesized, but positively associated with Barrett's esophagus, contrary to our hypothesis. Additional studies are needed in men and women to replicate these findings.
A cytoplasmic membrane-like fraction from cells of the Ehrlich mouse ascites carcinoma.

THE nature of the surface structure of many mammalian cells is still a matter of some uncertainty. Most of the evidence on this point has been garnered as a result of microscopic studies on sectioned cells1, except in the case of the erythrocyte; here, stromata can be prepared in quantity and studied by diverse means. To our knowledge, no isolations of analogous structures from other mammalian cells have been reported, although schemes for cell fractionation are available2,3. A search for methods of obtaining mammalian cell membranes in quantity is of importance, since availability would make possible a variety of studies which can be approached only by indirect means at present. This communication describes the isolation and partial characterization of a membranous, morphologically reproducible fraction from Ehrlich mouse ascites carcinoma cells.
A repetitive Dictyostelium gene family that is induced during differentiation and by heat shock

Abstract Clone pB41-6 (2.5 kb) contains sequences that are repeated 200–300 times in the Dictyostelium genome; about 40 of these sequences are part of a 4.5 kb repeated and apparently transposable genomic element. Clone pB41-6 hybridizes to a large number of cytoplasmic polyadenylated RNAs whose accumulation begins in the first hour of differentiation. In order to understand the regulation of these repeated sequences, we have sequenced pB41-6. It contains three long open reading frames in the "sense" strand. Remarkably, about 70 bases upstream of the transcription initiation site is a sequence identical to that responsible for induction of the Drosophila heat shock genes. A search of published sequences also generated a similar sequence upstream of one of the Dictyostelium actin genes. Indeed, we found that both pB41-6-related RNAs and actin mRNAs are increased as a result of heat shocking growing cells, and that transcription of pB41-6 sequences is induced by heat shock. Thus Dictyostelium contains a set of genes that are induced as a response to heat shock or to the stresses that trigger the initiation of development. We show here that the principal component of this "stress" is not amino acid starvation but the high density of the cells.
Production of achondroplasia in the chick embryo with thallium.

SummaryThallium sulfate produces a consistent and severe degree of achondroplasia in the chick embryo when injected on the fourth day of incubation. This abnormality appears to be similar to the genetic, and to some of the nutritional deficiency, types of chondrodystrophy. Thallium induced achondroplasia is not prevented by treating the embryo with manganese, biotin, nicotinamide or riboflavin, deficiencies of which have been reported to result in some type of chondrodystrophy in the chick embryo.
Incubation temperature and gonadal sex affect growth and physiology in the leopard gecko (Eublepharis macularius), a lizard with temperature-dependent sex determination.

Temperature-dependent sex determination (TSD), in which the temperature at which an egg incubates determines the sex of the individual, occurs in egg-laying reptiles of three separate orders. Previous studies have shown that the embryonic environment can have effects lasting beyond the period of sex determination. We investigated the relative roles of incubation temperature, exogenous estradiol, and gonadal sex (testis vs. ovary) in the differentiation of adult morphological and physiological traits of the leopard gecko, Eublepharis macularius. The results indicate that incubation temperature, steroid hormones, and gonads interact in the development of morphological and physiological characters with incubation temperature resulting in the greatest differences in adult phenotype. Incubation temperature did not affect reproductive success directly, but may influence offspring survival in natural situations through effects on adult female body size. Postnatal hormones seem to be more influential in the formation of adult phenotypes than prenatal hormones. These results demonstrate that TSD species can be used to investigate the effects of the physical environment on development in individuals without a predetermined genetic sex and thus provide further insight into the roles of gonadal sex and the embryonic environment in sexual differentiation. © 1995 Wiley-Liss, Inc.
Dance and Sport: The Tie that Binds, or the Bind that Ties?

Abstract Movement as an expressive act has surrendered to the more acceptable, secure, safer, and pedestrian forms of fitness and games. As a result, movement as a means of expression is a phrase without meaning to many young physical educators.
Effects of self‐monitoring and contingent reinforcement on on‐task behavior and academic productivity of learning‐disabled students: A social validation study

The purpose of this study was to investigate the social validity of behavior change produced by self-monitoring and contingent reinforcement upon the on-task behavior and academic productivity of six learning-disabled students using a single-case, multiple-treatment design. Subjects self-monitored their on-task behavior while concurrent measures of academic productivity were collected. This study employed two phases of self-monitoring and contingent reinforcement. Self-monitoring was broken down into its component parts: self-observation and self-recording. Contingent reinforcement consisted of verbally reinforcing improvements and meeting goals set for both on-task behavior and academic productivity. On-task behavior and academic productivity improved under both interventions. Improvements were commensurate to levels of on-task behavior and academic productivity exhibited by the subjects' nonhandicapped peers. Implications for research and practice are discussed.
Preservation and collection management: some common concerns

Awareness of the integral and necessary relationship between collection management and development and preservation programs has been increasing in recent years. At long last, collection managers and preservation specialists have begun to work together more closely and to identify areas of common concern.
Rationale for influx enhancement versus efflux blockade to increase drug exposure to the brain

Various methods of optimizing brain exposure to polar compounds have been examined. However, direct comparisons of the potential efficacy of these methods have not been forthcoming. The present study utilized a mathematical approach to compare the efficacy of two pharmacologic methods of improving brain drug distribution: uptake enhancement and efflux blockade. In the present simulation study, the pharmacokinetics of a hypothetical marker and modifier were described by differential equations. The relationship between modifier effect on marker uptake into, or efflux from, the brain and modifier concentration in serum (uptake enhancement) or brain tissue (efflux blockade) was described by the Hill equation. Uptake enhancement increased both the rate and extent of marker penetration into the brain. Efflux blockade resulted in delayed attainment of maximum marker concentration, and prolonged marker residence, in brain tissue. Under all conditions and doses examined, uptake enhancement was more effective than efflux blockade in maximizing brain tissue exposure to the marker. Although development of agents that enhance uptake of polar compounds may be limited by the potential deleterious effects of blood-brain barrier disruption, use of this approach in theory could represent a significant advancement in the treatment of brain disorders.
Contrasting patterns of coupling between the CH stretches and the large-amplitude motions in the molecules, CH3NH2, CH3OH2+ and CH3CH2

Abstract In each of the title molecules, torsional and inversion tunneling occurs between six equivalent minima. The coupling between these large-amplitude motions and the CH stretch vibrations stems from the variation of the CH stretching force constants as a function of the torsional and inversion coordinates. First principles 2D maps of the variation of the CH-stretch force constants are reported. Although the torsional barriers differ by more than a factor of 20, the torsion–inversion–vibration coupling is similar for two of the species, CH 3 NH 2 and CH 3 CH 2 , but is much weaker and qualitatively different in form for the third species, CH 3 OH 2 + .