cssi/SciSciGPT-SciSciNet huggingface dataset:
Influence of preparative procedures on the membrane viscoelasticity of human red cell ghosts

Abstract The effects of systematic variations in the preparative procedures on the membrane viscoelastic properties of resealed human red blood cell ghosts have been investigated. Ghosts, prepared by hypotonic lysis at 0°C and resealing at 37°C, were subjected to: (1) measurement of the time constant for extensional recovery ( t c ); (2) measurement of the membrane shear elastic modulus (μ) via three separate techniques; (3) determination of the membrane viscosity ( η m ) via a cone-plate Rheoscope. Membrane viscosity was also determined as η m =μ·t c . Compared to intact cells, ghosts had shorter t c , regardless of their residual hemoglobin concentration (up to 21.6 g/dl). However, prolonged exposure to hypotonic media did increase their recovery time toward the intact cell value. The shear elastic modulus, as judged by micropipette aspiration of membrane tongues ( μ p ), was similar for all ghosts and intact cells. This result, taken with the t c data, indicates that ghosts have reduced membrane viscosity. Rheoscopic analysis also showed that η m was reduced for ghosts, with the degree of reduction (approx. 50%) agreeing well with that estimated by the product μ p ·t c . However, flow channel and pipette elongation estimates indicated that the ghost membrane elastic modulus was somewhat elevated compared to intact cells. We conclude that: (1) ghosts have reduced membrane viscosity; (2) ghosts have membrane rigidities close to intact cells, except possibly when the membrane is subjected to very large strains; (3) the reduction in η m is not directly related to the loss of hemoglobin; (4) prolonged exposure of ghosts to low-ionic strength media increases the membrane viscosity toward its initial cellular level. These data indicate that the mechanical characteristics of ghost membranes can be varied by changing the methods of preparation and thus have potential application to further studies of the structural determinants of red cell membrane viscoelasticity.
Effectiveness of nupercaine hydrochloride and phenobarbital sodium in the suppression of ventricular tachycardia associated with acute myocardial infarction.

In 22 dogs with ventricular tachycardia accompanying myocardial infarction, Nupercaine hydrochloride was found to be a potent suppressor of ectopic impulses. When used alone Nupercaine also produced vomiting and convulsive movements. When combined with morphine, vomiting was eliminated, but convulsions still occurred. When combined with phenobarbital sodium or pentobarbital sodium, the ectopic impulse suppressor action of Nupercaine was enhanced and both vomiting and convulsive movements were prevented. The duration of ectopic impulse suppressor action was significantly greater in the phenobarbital-Nupercaine experiments than in any other group. No deaths occurred.
Interactions of gold with cytosolic selenium-containing proteins in rat kidney and liver

Rats injected with aurothioglucose (ATG) for 5 days were subsequently injected with [75Se]selenious acid and killed after 3 days. Kidney and liver cytosols were chromatographed on Sephadex G-150. 75Se in kidney was associated with high molecular weight (HMW), 85,000 Mr, 26,000 Mr, and 10,000 Mr proteins and with a nonprotein fraction. The elution profile of liver cytosol was similar to that of kidney, but without a 26,000 Mr protein. ATG injection increased the association of 75Se with all fractions of kidney cytosol except the 85,000 Mr fractions, which contained Se-glutathione peroxidase (SeGSHPx) activity; 75Se in liver was increased only in HMW fractions. Unfractionated kidney cytosolic SeGSHPx activity was decreased 14% by ATG injection, but liver enzyme activity was not changed. However, Sephadex G-150 chromatography showed that total and specific activities, respectively, were decreased 28 and 23% in kidney and 25 and 16% in liver. Au coeluted with HMW and 10,000 Mr 73Se-containing kidney proteins; the latter contained 50% of the Au eluted from the column. DEAE Sephacel chromatography of the 10,000 Mr kidney protein showed that both Au and 75Se were tightly associated with metallothionein-like proteins. This study demonstrates the interaction of Au with rat liver and kidney 75Se-containing proteins.
Vacuolar-proton-ATPase is involved in the response of cancer cells to ionizing radiation and is a new target for radiosensitization

Purpose: We have recently described a novel response of human cancer cells to radiation consisting of accumulation of acidic vesicular organelles (AVO) (Cancer Research, 61:439-444, 2001). Acidification of AVO was inhibited by bafilomycin A1 - a specific inhibitor of vacuolar-proton-ATPase. To examine the role of AVO function in the cellular response to radiation, we determined the effect of specific inhibitors of v-H+-ATPase (bafilomycin and concanamycin) on the clonogenic survival of various cancer cell lines. In addition, Northern analysis of mRNA encoding v-H+-ATPase was performed to elucidate possible mechanisms of post-radiation v-H+-ATPase regulation. Materials and Methods: Total RNA was isolated from human cancer cell lines including MCF-7 (breast), LoVo (colon), and LNCaP (prostate) cells 48 hours post-irradiation, and Northern analyses were performed. RNA was separated on a denaturing formaldehyde gel and blotted to a nylon membrane. Probes made from cDNAs to v-H+-ATPase were radioactively labeled, hybridized to the membranes, and exposed to X-ray film for determination of mRNA expression levels. Clonogenic survival assays were performed with MCF-7 and LoVo cell lines. Cells were plated at 30 cells/cm2, and irradiated 24 hours post-plating. Bafilomycin or concanamycin were added to culture media in various concentrations at the time of irradiation. The media was changed after a 24-hour incubation, and colonies were stained with crystal violet for counting 7 days post-irradiation. Results: Radiation-induced accumulation of acidic vesicular organelles in MCF-7, LoVo and LNCaP cells was associated with a two-fold increase in the steady-state level of mRNA for subunit c of v-H+-ATPase. Bafilomycin and concanamycin increased clonogenic cell death after irradiation in a dose-dependent manner. At low concentrations (bafilomycin 2nM, concanamycin 2pM) these agents acted as radiosensitizers, without significant toxicity to unirradiated cells. At 2nM, bafilomycin reduced the clonogenic survival of MCF-7 cells from 0.70 to 0.51 following 2 Gy (p=0.01) and from 0.27 to 0.17 following 4 Gy (p<0.01). Concanamycin (2 pM) reduced the clonogenic survival following exposure to 3 Gy from 0.45 to 0.28 (p=0.015). LoVo cells exhibited a surviving fraction of 0.42 after 3 Gy, versus 0.21 with bafilomycin (p<0.01). Conclusion: These results suggest that formation of acidic vesicular organelles after irradiation serves to protect cells against radiation damage, and that interference with their acidification can decrease clonogenic cell survival post-radiation. Low concentrations of v-H+-ATPase inhibitors such as bafilomycin A1 and concanamycin sensitize cancer cells to radiation without affecting non-irradiated cells. The vacuolar-proton-ATPase can therefore provide a new target for modulation of the radiosensitivity of human epithelial cancer cells.
Modelling evacuation behavior during the three mile island reactor crisis

Abstract This paper reports on the results of an empirical test of a causal model of nuclear reactor emergency evacuation decision-making which we have developed to assist emergency management officials to better understand public behavior during the TMI crisis. Logistic regression analyses on the survey data compiled for the Nuclear Regulatory Commission in the aftermath of the accident support all of the hypothesized direct linkages in the proposed model. The findings lead us to conclude that nuclear emergency evacuation behavior is predictable on the basis of locational, life-cycle, social status, attitudinal, and risk perception variables. Implications for future-oriented radiological emergency preparedness and response planning, and for reactor siting policies are discussed.
Underexcited Operations of Generators

This paper discusses two methods for controlling line-charging kilovars (kvar) and voltages on a lightly loaded 345-kv system. One method utilizes shunt reactors, while the other takes advantage of underexcited capabilities of modern turbine generators utilizing appropriate control. The conclusion, supported by experience, favors the underexcited operation in this situation.
Typologies of Violence Among Youth Who Encounter Child Welfare Systems

This study explored patterns of violent delinquent behaviors using latent class analysis (LCA). The study sample consisted of 1,013 11- to 17-year-olds who participated in Wave 1 of the second National Survey of Child and Adolescent Well-Being (NSCAW II). LCA was used to identify distinct patterns of violent delinquent behavior among youth involved in the child welfare system. The study found a model consisting of the two following classes: violent and normative. The study also examined how exposure to domestic violence, youths’ mental health, and youths’ substance abuse function as characteristics of the latent classes. Results showed members of the violent class were significantly more likely to report clinically significant depression and substance abuse. Racial differences did exist, showing members of the violent class were more likely to be Black than members of the normative class. The study found no differences on whether members of each class had been physically or sexually abused, experienced ph...
Mathematical modeling of chain-end scission using continuous distribution kinetics

Abstract Mathematical models that use continuous distributions to represent reacting polymer populations have been highly successful, and the method of moments is often used as a convenient means for obtaining solutions for the properties of the polymer population over time. However, there has been some controversy regarding the application of the method of moments for polymer degradation by chain-end scission. Here, we provide a rigorous treatment of chain-end scission using a continuous distribution for the polymer population and show that the method of moments has shortcomings for general use. As an alternative to the method of moments, we propose a solution method in which the continuous distribution is mapped to a set of discretized points, and the time-evolution of the distribution is obtained at the grid points. The results using this method are shown to agree well with the solution to the discrete model. The method is particularly well-suited for solving problems involving broadly distributed populations that are often found in nature.
Demonstration and characterization of the specific binding of growth hormone-releasing peptide to rat anterior pituitary and hypothalamic membranes.

Abstract Since the growth hormone-releasing peptide (GHRP), His- d -Trp-Ala-Trp- d -Phe-Lys-NH2, was found to specifically release growth hormone by a complementary but yet not clearly defined action on the pituitary as well as the hypothalamus, in vitro studies have been performed to demonstrate and characterize GHRP binding sites on peripheral membranes of both the rat anterior pituitary and hypothalamus. Optimum binding assay conditions were established using [ 125 I]Tyr-Ala-GHRP as the radioligand. The membrane binding sites were specific, reversible, saturable and time, temperature, pH and concentration dependent. Computerized analyses of competition experiments suggested two classes of binding sites in both pituitary and hypothalamic membranes. The maximum specific binding was observed at pH 5.0 than the physiological pH in both tissues. Pretreatment of the membranes with trypsin prevented specific binding. The increase in B max was statistically significant and showed a 2.0- to 8.9-fold and 5.8- to 11.2-fold in pituitary and hypothalamus, respectively, whereas the affinity constants (Kds) were not significant. Of the synthetic and natural neuropeptides that influence the release of GH from somatotrophs, only ( d -Lys 3 )GHRP, substance P antagonists and growth hormone-releasing factor analog were potent inhibitors of GHRP binding in both tissues.
Prevalence of Rape Myths in Headlines and Their Effects on Attitudes Toward Rape

The present research investigated the prevalence and effects of rape myths in newspaper headlines. In study 1, a content analysis of online news headlines from US media (N = 555) surrounding the 2003–2004 Kobe Bryant sexual assault case showed that 10% endorsed a rape myth. In study 2, students at a mid-sized university in the mid-western USA (N = 154) read headlines endorsing or not endorsing rape myths. Male participants exposed to myth-endorsing headlines were (a) less likely to think Bryant was guilty than those exposed to non-myth headlines, (b) more likely to hold rape-supportive attitudes than those exposed to non-myth headlines, and (c) more likely to hold rape-supportive attitudes than were female participants exposed to myth-endorsing headlines.
What Makes an Osteoclast Special

A paper published in Developmental Cell that I have continuously enjoyed over the years is "Induction and Activation of the Transcription Factor NFATc1 Integrate RANKL Signaling in Terminal Differentiation of Osteoclasts" by Takayanagi et al. I like this paper for many reasons. The first one is that it asks without preconceived idea a simple question: why the osteoclast differentiation factor RANKL, and not IL-1, triggers osteoclast differentiation, because both cytokines affect seemingly the same signaling cascade and transcription factors NF-KB and c-FOS. The approach was simple: a microarray of bone marrow stromal cells treated or not with RANKL or IL-1 to induce osteoclast differentiation. This analysis identified NFATc1, which the authors showed is the target of both c-FOS and NF-KB in osteoclasts. The authors checked all the boxes that need to be checked for a transcription factor determining cell differentiation, and more. Indeed, they identified calcium signaling as an activator of NFATc1, as well as genes whose expression is regulated by both c-FOS and NFATc1. This paper is beautifully written, the question posed is important, the experiments are of superb quality, and the advance for the field is highly significant. I always thought it was one of the better papers published in Developmental Cell pertaining to skeleton development. This PaperPick refers to "Induction and Activation of the Transcription Factor NFATc1 (NFAT2) Integrate RANKL Signaling in Terminal Differentiation of Osteoclasts," by H. Takayanagi, S. Kim, T. Koga, H. Nishina, M. Isshiki, H. Yoshida, A. Saiura, M. Isobe, T. Yokochi, J.-i. Inoue, E.F. Wagner, T.W. Mak, T. Kodama, and T. Taniguchi, published in December 2002. Video Abstract The first author of the original paper, Hiroshi Takayanagi, discusses how he decided at the time to investigate the transcriptional effectors of osteoclast RANKL signaling, within Tadatsugu Taniguchi's group.
Nucleic-acid immobilization, recognition and detection at chronopotentiometric DNA chips

Wide-scale DNA testing requires the development of fast, small, easy-to-use biosensing devices. Various synthetic oligonucleotides and DNA have thus been immobilized onto microfabricated thick-film carbon transducers for performing several new nucleic-acid assay protocols. These include hybridization detection of nucleic acid sequences, determination of small molecules (drugs, pollutants) based on their collection into the dsDNA layer or via monitoring their effect upon the intrinsic DNA oxidation signal, and direct adsorptive stripping measurements of ultratrace levels of nucleic acids. Transduction of these DNA recognition processes is accomplished by a new highly-sensitive constant-current stripping chronopotentiometric operation. Comparison to traditional electrodes indicates that the biosensing performance is not compromised by the use of mass-producible disposable transducers. Such thick-film DNA biosensors have been coupled to a compact, user-friendly, hand-held analyzer. Applicability for the detection of sequences from M. tuberculosis and HIV-1 DNAs is illustrated. Such activity in the author's laboratory, aimed at developing DNA-coated screen-printed electrodes, is reviewed.
Establishment of a consultation to announce the results of a breast biopsy.

Abstract Purpose Establishment of post-breast biopsy consultations to announce the results. Evaluation of this system in order to help improve the practice. Patients and methods The radio-senologists benefited from continuing medical education for the in-house announcement. Fifty patients (with malignant results) received questionnaires comprising 13 items and the possibility of free and anonymous comments. Results The authors present tools to help in the interview. Thirty-one questionnaires were returned by the patients and were analysed. Thirty patients (96.8%) considered the information provided as rather or fully sufficient, and only one considered that she did not have enough time to ask all of the questions she wanted to ask. Two patients (6.6%) found the scheduling of the subsequent appointments insufficient. The patients had a rather positive overall judgement about this consultation. Conclusion The radiologist may provide one of the consultations to announce the results, depending on their involvement in senology, their personal expertise and their integration in the care network.
A comparison of the effects of high frequency-low tidal volume and low frequency-high tidal volume mechanical ventilation

Ten neonates with severe lung disease were studied while mechanically ventilated with standard volume preset infant ventilators, using two different ventilatory patterns. Slow ventilatory rates and high tidal volumes were alternated with rapid rates and low tidal volumes; minute ventilation, F1o 2 , PEEP, and I:E ratios were held constant. Peak inspiratory pressure, mean airway pressure, expiratory time, Pa o 2 , Pa co 2 , pH, and arterial blood pressure were measured and compared for each frequency-tidal volume combination. The best arterial oxygenation occurred at the combination of settings that produced the highest mean airway pressure and always during low frequency-high tidal volume ventilation (P
Modeling freshwater fish distributions using multiscale landscape data: A case study of six narrow range endemics

Species distribution models (SDMs) have become integral tools in scientific research and conservation planning. Despite progress in the assessment of various statistical models for use in SDMs, little has been done in way of evaluating appropriate ecological models. In this paper, we evaluate the multiscale filter framework as a suitable theoretical model for predicting freshwater fish distributions in the upper Green River system (Ohio River drainage), USA. The spatial distributions of six fishes with contrasting biogeographies were modeled using boosted regression trees and multiscale landscape data. Species biogeography did not appear to affect predictive performance and all models performed well statistically with receiver operating characteristic area under the curve (AUC) ranging from 0.87 to 0.98. Predictive maps show accurate estimations of ranges for five of six species based on historical collections. The relative influence of each type of environmental feature and spatial scale varied markedly with between species. A hierarchical effect was detected for narrowly distributed species. These species were highly influenced by soil composition at larger spatial scales and land use/land cover (LULC) patterns at more proximal scales. Conversely, LULC pattern was the most influential feature for widely distributed at all spatial scales. Using multiscale data capable of capturing hierarchical landscape influences allowed production of accurate predictive models and provided further insight into factors controlling freshwater fish distributions.
The computer background of incoming freshman: looking for emerging trends

As part of a longitudinal study begun in 1985, incoming Bentley College freshmen were asked to complete questionnaires about their pre-college computer experience. Although nearly all students came from high schools with computers and more than 80% of them had studied BASIC, just under half had used a word processor. Even fewer (less than 20%) had used either a spreadsheet or a database management system, though the actual percentage has risen over the three years for which data exist. The increase in the number of schools teaching Pascal noticed between 1984 and 1985 persisted in 1986. However, though nearly 46% of the schools from which 1986 graduates came taught Pascal, only half that percentage actually studied the language. Almost half the students used computers outside school during their high school years, but most of that use involved playing games.
Automating probabilistic environmental decision analysis

Environmental Decision Analysis (EDA) appears to be evolving into a recognized environmental specially. Decision analysis can be challenging in all fields, but appears to be particularly difficult in environmental applications because of the diverse constituencies participating in decisions, the debatable and rapidly evolving state of environmental science and engineering, the structure and mandates of environmental regulation, the constant struggle with economic, ethical, social and political considerations, and the high degree of uncertainty about much of the available information. This manuscript presents quantitative algorithms for analyzing environmental decisions. Details will also be provided on a computational expression of these algorithms titled PDA - Probabilistic Decision Analysis. PDA automates the essential computations of deterministic or probabilistic EDA. PDA also provides several pre- and post-processor features that allow users to experiment with alternative methods of expressing uncertainty, and supports algorithms for examining the robustness of implied decisions.
Rapid acquisition of oral phencyclidine self-administration in food-deprived and food-satiated rhesus monkeys: Concurrent phencyclidine and water choice

Eight rhesus monkeys were trained to self-administer orally-delivered phencyclidine, with water concurrently available, under a fixed ratio (FR) schedule during daily 3-hr sessions. Liquid deliveries (0.55 ml) were contingent upon lip-contact responses on solenoid-operated drinking spouts. During the sessions, phencyclidine and water were available under FRs ranging from 1 to 16. Water was always available between sessions (FR 1), and food initially was available 24 hr/day. In Experiment 1 the monkeys initially were given access to water (FR 1) during the 3-hr sessions. Subsequently, phencyclidine (0.25 mg/ml) was substituted for water, and the monkeys were reduced to 85 percent of their free-feeding weights. The FR value was then increased from 1 to 8. Next, the monkeys received concurrent access to water from one spout and phencyclidine from the other (each under the FR 8 schedule), then the FR value was increased to 16 for both drug and water. Orally-delivered phencyclidine was rapidly demonstrated to function as a reinforcer (37.2 sessions) without using food to induce drinking. In Experiment 2 a similar procedure was used for another group of monkeys, except the monkeys remained food satiated throughout the acquisition phase. Phencyclidine was rapidly demonstrated to function as a reinforcer (25.9 sessions), although intakes were lower than in Experiment 1. After concurrent phencyclidine- and water-maintained performance stabilized at FR 16, the monkeys were food deprived, and phencyclidine intake increased to the levels reported in Experiment 1. Food deprivation greatly enhanced the reinforcing effect of phencyclidine and changed the temporal pattern of responding, but neither food deprivation nor food-induced drinking were necessary conditions to demonstrate the drug's reinforcing effects.
Very Low Drive Voltage Substrate Removed GaAs/A1GaAs Electro-Optic Modulators

We report electro-optic modulators with drive voltages as low as 0.3 V at 1.55 mum. The device was realized by removing the growth substrate and utilizes doped quantum wells as electrodes to obtain tight optical confinement and high electrical field. This is more than an order of magnitude reduction in drive voltage from our previous design. The on chip propagation loss was less than 8 dB/cm, 3 dB/cm of which was due to free carrier loss. To our knowledge, this is the lowest drive voltage obtained for any optical modulator.
Nonlinear interactions in a parametrically excited system with widely spaced frequencies

An investigation is presented into the transfer of energy from high- to low-frequency modes. The method of averaging is used to analyze the response of a two-degree-of-freedom system with widely spaced frequencies and cubic nonlinearities to a principal parametric resonance of the high-frequency mode. The conditions under which energy can be transferred from high- to low-frequency modes, as observed in the experiments, are determined. The interactions between the widely separated modes result in various bifurcations, the coexistence of multiple attractors, and chaotic attractors. The results show that damping may be destabilizing. The analytical results are validated by numerically solving the original system.
Pharmacokinetics of inhibition of adenosine deaminase by erythro-9-(2-hydroxy-3-nonyl)adenine in CBA mice

The pharmacokinetics of erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA) inhibition of adenosine deaminase (ADA) was measured in vivo in CBA mice. The in vivo assay utilized injection of 10-100 nmoles [2-3H]adenosine and measurement of blood 3H2O 20 min later. A single oral dose of EHNA (50 mg/kg) totally inhibited ADA for 4 hr and caused a large increase in conversion of [2-3H]adenosine to [2-3H]ATP. EHNA (3 mg/kg) decreased deamination by 50% for 2-6 hr, depending on the dose of adenosine used. Mice dosed with EHNA (100 mg/kg) once daily for 7 days showed the same ADA recovery rate as mice dosed only once. High single oral doses of EHNA had no effect on blood ATP and GTP pools.
Kalman-filter fringe tracking in an optical interferometer

In a class of optical interferometers, two samples of the captured light are combined in the pupil plane, dispersed, and focused to form a channeled spectrum. Shifts of the resulting fringe pattern due, for example, to the rotation of the instrument or changes in the propagation medium, must be tracked and, in some cases, compensated for the instrument to perform properly. The performance of the fringe-tracking estimator sets the faint limit of the instrument for a given suite of disturbances to the optical path difference (OPD) through the two sides of the interferometer. A nearly optimal fringe tracker may be constructed as a Kalman filter that includes a correct representation of the statistical properties of the OPD time series and that processes the detected photons individually. The use of a suboptimal filter is likely to be necessary both because of the difficulty of properly representing the OPD statistics and because of the computational burden of the complete, nonlinear, photon-by-photon estimator running in real time. We discuss a portion of the study of fringe trackers that has been carried out at SAO for the IOTA (ground-based) and POINTS (space-based) interferometry projects. We also present the results obtained from a Kalman filter fringe tracker running on simulated data. When the simulated OPD is obtained by numerically solving a second order differential equation with a white Gaussian driving term, an augmented state extended Kalman filter substantially outperforms a similar filter with an unaugmented state.
Rethinking healthcare transitions and policies: Changing and expanding roles in transitional care:

The breakdown of care transitions between various healthcare facilities, providers, and services is a major issue in healthcare, and accounts for over US$15 billion in healthcare expenditures annually. The transition between inpatient care and home care is a very delicate period where, too often, chronically ill patients get worse and wind up back in the hospital. This re-admission roller coaster is due in part to weak transitional care planning compounded by poor communication and coordination between healthcare providers, patients, and caregivers. The lack of a health information network and the resulting gap in transitional care exacerbates the incidence of preventable errors, increases the number of inpatient re-admissions, and adds to the rising cost of healthcare. Care navigation models provide a viable solution to address the unique characteristics of each patient transition and to prevent the current gap in care delivery. These models offer a framework for patient information exchange, interdiscip...
Nonlinear Effects on the Stiffness of Bolted Joints

Axisymmetric finite element modeling of bolted joints was performed to show the effects of the magnitude and position of the external load, member thickness, and member material on the bolt and member stiffnesses. The member stiffness of the bolted joint was found to decrease 10 to 42 percent for the 20-mm to 8-mm bolts, respectively, as the magnitude of the external load was increased. Member stiffness appears to be independent of the radial location of the external load and increases as the member thickness decreases. Member stiffness decreased by a factor of 2.5 to 3 with a change in the member material from steel to aluminum. The cast iron members had a decrease in member stiffness of a factor of 1.7 to 1.9. The aluminum over cast iron combination had a member stiffness between the aluminum and cast iron alone. Bolt stiffnesses varied by less than two percent for changes in the magnitude of the external load for all bolt sizes and member materials, except for the 8-mm bolt where stiffness increased by approximately 11 percent. Changes in radial position of the external load had no effect on the bolt stiffness. A 3 to 13-percent decrease in the bolt stiffnessmore » was found when changing from steel to aluminum members. A 2 to 3-percent bolt stiffness decrease resulted when the member material was changed from steel to cast iron and similarly from steel to the aluminum over cast iron combination.« less
A new model for preclinical testing of dermal substitutes for human skin reconstruction

Background Currently, acellular dermal substitutes used for skin reconstruction are usually covered with split-thickness skin grafts. The goal of this study was to develop an animal model in which such dermal substitutes can be tested under standardized conditions using a bioengineered dermo-epidermal skin graft for coverage.
Scattering of μ − Mesons by Nuclei

The effect of finite nuclear size on the scattering of ${\ensuremath{\mu}}^{\ensuremath{-}}$ mesons is calculated for a nucleus $Z=80$, $R=1.2{A}^{\frac{1}{3}}\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}13}$ cm. The nucleus is considered as a uniformly charged sphere. The ${\ensuremath{\mu}}^{\ensuremath{-}}$ mesons have $\frac{v}{c}=0.2$ corresponding to an energy $E=2.1$ Mev. It is found that the left-right asymmetry in the scattering of polarized ${\ensuremath{\mu}}^{\ensuremath{-}}$ mesons is decreased from that for a point nucleus. However, considerable asymmetry remains at large angles.
Exact Lattice Supersymmetry: the Two-Dimensional N = 2 Wess-Zumino Model

We study the two-dimensional Wess-Zumino model with extended $N=2$ supersymmetry on the lattice. The lattice prescription we choose has the merit of preserving exactly a single supersymmetric invariance at finite lattice spacing a. Furthermore, we construct three other transformations of the lattice fields under which the variation of the lattice action vanishes to ${O(ga}^{2})$ where g is a typical interaction coupling. These four transformations correspond to the two Majorana supercharges of the continuum theory. We also derive lattice Ward identities corresponding to these exact and approximate symmetries. We use dynamical fermion simulations to check the equality of the mass gaps in the boson and fermion sectors and to check the lattice Ward identities. At least for weak coupling we see no problems associated with a lack of reflection positivity in the lattice action and find good agreement with theory. At strong coupling we provide evidence that problems associated with a lack of reflection positivity are evaded for small enough lattice spacing.
Methyl bromide deposition to soils

Abstract Methyl bromide is the single largest contributor of stratospheric Br and an important contributor to stratospheric ozone depletion. Soils have recently been identified as a significant sink of methyl bromide ( Shorter et al., 1995 , Nature 377 (6551), 717–719). As is the case for other trace gases, methyl bromide deposition rates vary for different ecosystems and depend on soil characteristics. The limited data available prevents an accurate global estimate but does allow initial attempts to establish the importance of this sink. We have investigated the methyl bromide sink for four different ecosystems, and found deposition rates that range from about 0.02±0.005–0.38±0.170 cm s -1 . These rates result in a global sink that is higher, although of the same order of magnitude, than that reported by Shorter et al. (1995) . The partial lifetime of methyl bromide with regard to soil sink is estimated to be between 0.97 and 3.54 yr resulting in a mean total lifetime of 0.61 yr. Estimates of a methyl bromide ozone depletion potential (ODP) range between 0.22 and 0.48. About half of the uncertainty in the ODP estimates is associated with current global methyl bromide soil-sink estimates.
RNA synthesis inhibitors increase melatonin production in Y79 human retinoblastoma cells

Y79 human retinoblastoma cells synthesize melatonin in cell culture thus providing a unique preparation for studying the regulation of melatonin biosynthesis in mammalian retinas. We have previously demonstrated that Y79 cells express NAT and HIOMT activity and produce melatonin in a cAMP- and protein synthesis-dependent manner by increasing NAT, and not HIOMT activity, as has been demonstrated in other retinal and pineal melatonin synthesizing systems. We have extended these studies to investigate the role of RNA synthesis in melatonin regulation, and report here that RNA synthesis inhibitors do not suppress melatonin production in Y79 retinoblastoma cells. Rather, at intermediate concentrations, the inhibitors actinomycin D and camptothecin increase melatonin levels. Camptothecin, a topoisomerase I inhibitor, also increased NAT activity and accumulated cAMP levels in a calcium-dependent manner. This effect on cAMP did not appear to occur through phosphodiesterase, and other regulators of retinal melatonin such as melatonin degradation or components of the dopamine system were unaffected. These results are in contrast with the suppression of melatonin synthesis by RNA synthesis inhibitors observed in rat and chick pineal glands and in chick retinas.
Chronoamperometric current at finite disk electrodes

Abstract The chronoamperometric current at a stationary finite disk electrode is studied using both analytical and digital simulation techniques. The exact long-time expansion of the current is obtained and its short-time behavior is considered. Digital simulation of the current using an explicit hopscotch algorithm is presented. In contrast to the usual explicit difference method, the ‘hopscotch’ algorithm is unconditionally stable, and thus, it is particularly suited for studying electrochemical problems at intermediate and long times. A simple analytic expressions for the current, which is accurate to 0.6% for all times, is presented.
Relationships of the common femoral artery

The relationships of the femoral artery to the anterior superior spine, the pubic symphysis, and the public tubercle were measured in 100 adult males. The average distance from the pubic tubercle to the femoral artery pulsation was 4.5 cm, from the symphysis pubis to the femoral artery pulsation was 7.7 cm, and the position of the femoral artery on a line between the symphysis and the anterior superior spine averaged its mid point. From a clinical point of view, the femoral artery is most easily located along the inguinal ligament at a point between two and three finger breadths from the pubic tubercle.
Structural Realism for Secondary Qualities

This paper outlines and defends a novel position in the color realism debate, namely structural realism. This position is novel in that it dissociates the veridicality of color attributions from the claim that physical objects are themselves colored. Thus, it is realist about color in both the semantic and epistemic senses, but not the ontic sense. The generality of this position is demonstrated by applying it to other “secondary qualities,” including heat, musical pitch, and odor. The basic argument proceeds by analogy with the theory of measurement. I argue that perceptual experiences are analogous to numerical structures in that they are suitable for measurement, but only report measured values after they have been linked to states of a measurement device via calibration. Since the calibration of our sensory apparatus varies with context, it is inappropriate to identify specific experiences with specific properties in the world. Rather, it is structural relations between possible experiences which represent relations between possible external properties, and it is at the level of these structural relationships that veridicality is appropriately assessed.
Vortex-lattice melting in Nb.

Detailed measurements and analysis of the temperature and magnetic field dependence of the magnetization and the magnetic relaxation of Nb films have been carried out. An irreversibility line has been identified, below which the remanent magnetization was found to decay logarithmically in time. The data were quantitatively compared to predictions of flux creep, vortex glass, and vortex-lattice-melting models. Only the vortex-lattice-melting model self-consistently explained the data.
Use the Forces, Luke: Soldiers and the Democratic Peace

Civil–Military Dynamics, Democracy, and International Conflict: A New Quest for International Peace. By Seung–Whan Choi, Patrick James. New York: Palgrave Macmillan, 2005. 224 pp., $69.95 (ISBN: 1-4039-6485-8). Civil–Military Dynamics, Democracy, and International Conflict is an ambitious and methodologically sophisticated, but conceptually underdetermined, monograph. In it, Seung-Whan Choi and Patrick James propose to extend recent advances in the democratic peace literature. Focusing on Bruce Russett and John Oneal's (2001) blending of systemic and dyad-specific variables, they seek in particular to fill what they identify as two conceptual lacunae in the democratic peace literature: the impact of military influence and political communications, respectively, on policy. Unfortunately, the book suffers from too much ambition and too little conceptual clarity. Choi and James simply attempt to do too much, with too little, in too many scholarly domains—including formal models of decision making, civil–military relations, the democratic peace, crisis bargaining, and formal models of conflict, among others. Their ambitions exceed the empirical evidence they bring to bear. Moreover, their variables are poorly operationalized, and they spend far too little time theorizing about civil–military relations and political communications to do justice to either concept. Advanced graduate students and formal modelers will find their application of neural network models to be technically interesting. However, students of the democratic peace and of civil–military relations will find little to commend this slim volume. Choi and James start with an important theoretical puzzle. Whatever the “peace-proneness” of democracies might be, they ask, if soldiers exercise decisive influence over foreign policy decision making, will their professional “war-proneness” override democracy's peace-proneness? In asking this question, …
Generating a Random Signed Permutation with Random Reversals

Signed permutations form a group known as the hyperoctahedral group. We bound the rate of convergence to uniformity for a certain random walk on the hyperoctahedral group that is generated by random reversals. Specifically, we determine that O(n log n) steps are both necessary and sufficient for total variation distance and l2 distance to become small. This random walk arose as the result of an effort in molecular biology to model certain types of genome rearrangements.
The effect of nonnormality on near-replicate lack-of-fit tests

We examine the effect of nonnormality on the distributions of near-replicate lack-of-fit F-tests. We show that when the number of clusters is large, the distributions of the lack-of-fit tests depend on the kurtosis of the error distribution, and that heavy-tailed error distributions can inflate significantly the sizes of the tests. This behaviour is also evident in small samples, where some lack-of-fit tests are clearly more affected than others by nonnormality. Two modifications of the F-tests are suggested to eliminate the effect of the kurtosis on the limiting null distributions, and their behaviour is studied for small samples. Les auteurs decrivent l'effet de la non normalite sur la loi, sous l'hypothese nulle, de tests d'adequation de Fisher pour des quasi-replicats. Ils montrent que lorsque le nombre de groupes est grand, la distribution de ces tests depend du degre d'aplatissement de la loi de l'erreur et que si les queues de cette derniere sont lourdes, le seuil observe des tests peut augmenter de facon significative. Ce comportement se manifeste aussi dans de petits echantillons, ou certains tests souffrent davantage que d'autres de l'absence de normalite. Ceci conduit les auteurs a proposer deux modifications des tests qui affranchissent la loi asymptotique de sa dependance par rapport au coefficient d'aplatissement. Ils examinent alors l'impact de ces suggestions methodologiques dans de petits echantillons.
Split liver transplantation

We analyzed the results of 55 patients who underwent split liver transplantation at our center between September 1996 and December 2008, 30 adults (54.5%) and 25 children (45.5%). Median follow-up was 12 years. Overall patient survival was 71%, adult 70% and pediatric 72%. Mean patient survival was 61.58 months, and mean graft survival was 44.35 months. Pediatric survival and pediatric graft survival after 1 and 5 years were 84% and 72% and 72% and 52.4%, respectively. Adult survival and adult graft survival after 1 and 5 years were 75% and 66.2% and 60.7% and 51.5%, respectively. Twelve patients required retransplantation, 6 for primary nonfunction, 3 for chronic rejection, and 3 for vascular complications. Blood groups of the recipient patients were: 34 O, 14 A, 7 B, and 0 AB. The use of split liver for adult and pediatric populations allows us to expand the cadaveric donor pool and has the potential to significantly reduce waiting list mortality, especially for certain blood groups.
Sibling species in the Lutzomyia longipalpis complex differ in levels of mRNA expression for the salivary peptide, maxadilan

Maxadilan is a small ( ∪ 7 kDa) protein found in the saliva of sand fly species in the Lutzomyia longipalpis complex, vectors of the parasite causing visceral leishmaniasis, Leishmania chagasi . It is a potent vasodilator and also has immunomodulatory affects. Maxadilan recovered from different sibling species of the Lu. longipalpis complex differ in amino acid content by as much as 23%, however all variants possess equivalent vasodilatory activity. Therefore, the dramatic differences in vasodilatory activity of the saliva from different sibling species is probably due to differences in the amounts of maxadilan in their saliva. This is significant because it has been suggested that maxadilan may influence the pathogenesis of leishmanial infections. In this study we measured the amount of maxadilan messenger RNA (mRNA) per pair of salivary glands from individual sand flies by quantitative reverse transcription polymerase chain reaction (RT-PCR) using a competitive method. We report a method using the gene of interest, in this case maxadilan, amplified by the PCR from genomic DNA, as a competitor in the quantitative RT-PCR, taking advantage of differences in the size of these products due to the presence of an intron. Significant differences in amounts of maxadilan mRNA among colonies from Central and South America are described. We found a strong correlation between the amount of maxadilan mRNA detected in salivary glands of different Lu. longipalpis sibling species and previously described differences in the size of erythemas produced by the bite of these species. Therefore, variation in the amount of mRNA suggests that differences in the vasodilatory properties of saliva among the different sibling species are the result of differences in the amount of maxadilan present in the saliva and not differences in the potency of maxadilan peptide variants. The geographical distribution of species with high or low levels of maxadilan gene expression are concordant with the distribution of atypical cutaneous leishmaniasis resulting from infection with Le. chagasi , lending credence to earlier suggestions that maxadilan may be involved with visceralization of this parasite.
Analysis of a Model with Multiple Infectious Stages and Arbitrarily Distributed Stage Durations

Infectious diseases may have multiple infectious stages with very different epidemiological attributes, including infectivity and disease progression. These stages are often assumed to have exponentially distributed durations in epidemiological models. However, models that use the exponential distribution assumption (EDA) may generate biased and even misleading results in some cases. This discrepancy is particularly damaging if the models are employed to assist policy-makers in disease control and interventions. This paper studies a mathematical model that includes multiple infectious stages and general distributions for the stage durations (with the exponential distribution as a special case). Formulas for the control reproductive number, Rc, and the basic reproductive number, R0, are derived, which can be conveniently applied to models in which specific stage distributions are assumed. It is also shown that the disease dynamics are determined by the reproductive numbers.
A Comparative Study of the Effects of a Developmentally Based Instructional Model on Young Children with Autism and Young Children with Other Disorders of Behavior and Development

The progress made by two different groups of preschool children, those with autism or related disorders and those with other emotional/behavioral and developmental disorders, in a particular instru...