cssi/SciSciGPT-SciSciNet huggingface dataset:
RESISTing reliability degradation through proactive reconfiguration

Situated software systems are an emerging class of systems that are predominantly pervasive, embedded, and mobile. They are marked with a high degree of unpredictability and dynamism in the execution context. At the same time, such systems often need to satisfy strict reliability requirements. Most current software reliability analysis approaches are not suitable for situated software systems. We propose an approach geared to such systems, which continuously furnishes refined reliability predictions at runtime by incorporating various sources of information. The reliability predictions are leveraged to proactively place the software in the optimal configuration with respect to changing conditions. Our approach considers two representative architectural reconfiguration decisions that impact the system's reliability: reallocation of components to processes and changing the architectural style. We have realized the approach as part of a framework intended for mission-critical settings, called REsilient SItuated SofTware system (RESIST), and evaluated it using a mobile emergency response system.
Anesthetic Efficacy of Lidocaine/Meperidine for Inferior Alveolar Nerve Blocks in Patients with Irreversible Pulpitis

The purpose of this prospective, randomized, single-blind study was to compare the anesthetic efficacy of lidocaine with epinephrine to lidocaine plus meperidine with epinephrine for inferior alveolar nerve blocks (IAN) in patients with mandibular posterior teeth experiencing irreversible pulpitis. Forty-eight emergency patients diagnosed with irreversible pulpitis of a mandibular posterior tooth randomly received, in a single-blind manner, 36 mg of lidocaine with 18 mug epinephrine or 36 mg of lidocaine with 18 mug of epinephrine plus 36 mg meperidine with 18 mug epinephrine, using a conventional inferior alveolar nerve block. Endodontic access was begun 15 minutes after solution deposition, and all patients were required to have profound lip numbness. Success was defined as no or mild pain (visual analog scale recordings) upon endodontic access or initial instrumentation. The success rate for the inferior alveolar nerve block using the lidocaine solution was 26%, and for the lidocaine/meperidine solution, the success rate was 12%. There was no significant difference (p = 0.28) between the two solutions. In conclusion, for mandibular posterior teeth with irreversible pulpitis, the addition of 36 mg of meperidine to a lidocaine solution administered in a conventional IAN block did not improve the success rate over a standard lidocaine solution.
Caspase-dependent secondary lens fiber cell disintegration inα A-/αB-crystallin double-knockout mice

αB-crystallin has been demonstrated, in tissue culture experiments, to be a caspase 3 inhibitor; however, no animal model studies have yet been described. Here, we show that morphological abnormalities in lens secondary fiber cells of αA-/αB-crystallin gene double knockout (DKO) mice are consistent with, and probably result from, elevated DEVDase and VEIDase activities, corresponding to caspase 3 and caspase 6, respectively. Immunofluorescence microscopy revealed an increased amount of caspase 6, and the active form of caspase 3, in specific regions of the DKO lens, coincident with the site of cell disintegration. TUNEL labeling illustrated a higher level of DNA fragmentation in the secondary fiber lens cells of DKO mice, compared with wild-type mice. Using a pull-down assay, we show interaction between caspase 6 and αA- but not αB-crystallin. These studies suggest that α-crystallin plays a role in suppressing caspase activity, resulting in retention of lens fiber cell integrity following degradation of mitochondria and other organelles, which occurs during the apoptosis-like pathway of lens cell terminal differentiation.
Homochiral coordination polymer with infinite double-stranded helices.

Hydrothermal reaction of 4,4-trimethylenedipyridine (tmdp) with ZnI2 under 175 °C yields a novel compound, {[Zn2I4(tmdp)2]n·[Zn2I4(tmdp)2]n}, which has a chiral infinite double-stranded helical structure consisting of two single-stranded helices of the same handedness.
A Ring-Laser Type Quasi-Optical Oscillator Using Leaky-Wave Antenna

This paper presents a novel ring-laser type quasi-optical oscillator based on leaky-wave antenna, which can be used as an alternative to conventional configurations employing VCOs. It consists of a gain-control amplifier, a phase-shifter and a microstrip leaky-wave antenna. The feature of this structure is that the leaky-wave antenna not only serves as a radiation element, but also provides oscillation feedback. The beam-scanning capability of this quasi-optical oscillator is also demonstrated experimentally.
Rigorous and Accurate Enclosure of Invariant Manifolds on Surfaces

Knowledge about stable and unstable manifolds of hyperbolic fixed points of certain maps is desirable in many fields of research, both in pure mathematics as well as in applications, ranging from forced oscillations to celestial mechanics and space mission design. We present a technique to find highly accurate polynomial approximations of local invariant manifolds for sufficiently smooth planar maps and rigorously enclose them with sharp interval remainder bounds using Taylor model techniques. Iteratively, significant portions of the global manifold tangle can be enclosed with high accuracy. Numerical examples are provided.
Quarkonium Spectral Function from Anisotropic Lattice

Abstract We discuss the behavior of charmonia and bottomonia correlators and spectral functions above the deconfinement temperature and determine melting temperatures for different mesonic states.
Effects of vocal training and phonatory task on voice onset time.

Summary Objectives/Hypothesis: The purpose of this study was to examine the temporal-acoustic differences between trained singers and nonsingers during speech and singing tasks. Methods: Thirty male participants were separated into two groups of 15 according to level of vocal training (ie, trained or untrained). The participants spoke and sang carrier phrases containing English voiced and voiceless bilabial stops, and voice onset time (VOT) was measured for the stop consonant productions. Results: Mixed analyses of variance revealed a significant main effect between speech and singing for /p/ and /b/, with VOT durations longer during speech than singing for /p/, and the opposite true for /b/. Furthermore, a significant phonatory task by vocal training interaction was observed for /p/ productions. Conclusions: The results indicated that the type of phonatory task influences VOT and that these influences are most obvious in trained singers secondary to the articulatory and phonatory adjustments learned during vocal training.
Phenotypic lag and mutation to 6-thioguanine resistance in diploid human lymphoblasts

Abstract Mutants of a diploid human lymphoblast line resistant to 6-thioguanine (6TG) appear 6–16 generations after treatment with any of a diverse group of mutagens: methylnitrosourea (MNU), methylnitrosoguanidine (MNNG), ICR-191 5-bromodeoxyuridine (BUdR). A hypothesis is advanced that expression of the 6-thioguanine-resistant state may require the removal of essentially all pre-existing hypoxanthine—guanine phosphoribosyl transferase (HGPRT) molecules via division, dilution, and protein turnover. Design of protocols for quantitative mutation assays requires attention to this phenomenon.
Simulation study of chiral two-dimensional ultraviolet spectroscopy of the protein backbone.

Amide n−π* and π−π* excitations around 200 nm are prominent spectroscopic signatures of the protein backbone, which are routinely used in ultraviolet (UV) circular dichroism for structure characterization. Recently developed ultrafast laser sources may be used to extend these studies to two dimensions. We apply a new algorithm for modeling protein electronic transitions to simulate two-dimensional UV photon echo signals in this regime and to identify signatures of protein backbone secondary (and tertiary) structure. Simulated signals for a set of globular and fibrillar proteins and their specific regions reveal characteristic patterns of helical and sheet secondary structures. We investigate how these patterns vary and converge with the size of the structural motif. Specific chiral polarization configurations of the UV pulses are found to be sensitive to aspects of the protein structure. This information significantly augments that available from linear circular dichroism.
Alkaline phosphatase reactivity in the vagina and uterovaginal junction sperm-storage tubules of turkeys in egg production: implications for sperm storage

1. Currently there remains contradictory information on the localisation and possible role of alkaline phosphatase (AP) in the chicken and Japanese quail oviducts. 2. Using turkeys with a hard-shelled egg in their uteri, vaginal and uterovaginal junction mucosae were stretched and fixed as whole mounts prior to the histochemical localisation of AP activity. 3. Scattered AP reactive cells were observed in the vaginal and uterovaginal junction surface epithelia and intense AP reactivity of the sperm-storage tubule (SST) epithelium, localised to its apical border. 4. We suggest that such AP reactivity in hens in egg production may reflect cell differentiation and proliferation in the vagina and SST and possibly a mechanism for the transfer of lipid from the SST epithelia to resident sperm.
Characteristics of cascade impactors in size determination of diesel particles

Abstract Cascade impactors of various designs have been used extensively in air sampling and inhalation toxicology to determine the size distribution of airborne aerosols. In this study, the internal losses of diesel exhaust particles in a multijet Mercer impactor, a low pressure Battelle impactor, and an Anderson impactor were determined by scintillation counting of gamma tagged diesel particles. Total interstage losses were 8–33%. However, losses in the three impactors were comparable on stages where most of the mass was found, ranging from 17 to 25%. Apiezon and Vaseline coated impaction surfaces reduced the internal losses of diesel particles and yielded larger mass median aerodynamic diameters compared to the uncoated impactors.
Ligand occupation and the functional states of the nicotinic-cholinergic receptor

Abstract Simultaneous measurements of receptor occupation and the change in ion permeability elicited by the ligands enable one to define the linkage between agonist association and activation of the ion channel. The nicotinic receptor behaves effectively as a co-operative dimer. Two agonist molecules are required for activation while a single bound antagonist is sufficient to block the response of the receptor oligomer. The two agonist binding sites on the oligomer do not show precise functional equivalence as might be anticipated from the arrangement of subunits of this protein in the membrane.
Bayesian Updating with Structural Reliability Methods

Bayesian updating is a powerful method to learn and calibrate models with data and observations. Because of the difficulties involved in computing the high-dimensional integrals necessary for Bayesian updating, Markov chain Monte Carlo (MCMC) sampling methods have been developed and successfully applied for this task. The disadvantage of MCMC methods is the difficulty of ensuring the stationarity of the Markov chain. We present an alternative to MCMC that is particularly effective for updating mechanical and other computational models, termed Bayesian updating with structural reliability methods (BUS). With BUS, structural reliability methods are applied to compute the posterior distribution of uncertain model parameters and model outputs in general. An algorithm for the implementation of BUS is proposed, which can be interpreted as an enhancement of the classic rejection sampling algorithm for Bayesian updating. This algorithm is based on the subset simulation, and its efficiency is not dependent on the number of random variables in the model. The method is demonstrated by application to parameter identification in a dynamic system, Bayesian updating of the material parameters of a structural system, and Bayesian updating of a random field–based finite-element model of a geotechnical site.
The public choice of educational choice

The very small literature explaining (i) how citizens have voted in two California voucher referenda, (ii) how legislators have voted on voucher bills in the State of Florida and the US Congress, and (iii) the variation across states in charter school provisions is summarized. New empirical evidence documenting the cross-state variation in the success of voucher referenda and voucher bills is examined. Voucher bill characteristics and state characteristics play important roles. Voucher bills have been passed only in the more conservative Republican states, and almost all of the successful voucher programs have been targeted at large, struggling school districts.
Allotransplantation de tissus composites et chirurgie plastique: Les premières applications cliniques

L'allotransplantation tissulaire est definie par le transfert de tissus preleves sur un sujet donneur en etat de mort encephalique et revascularises chez un sujet receveur. Elle repose sur la maitrise des techniques microchirurgicales et sur l'induction d'une immunosuppression therapeutique chez le receveur. Les premieres allogreffes (de tendons flechisseurs, de diaphyses femorales et de genoux, de mains, de nerfs, de larynx) ont ouvert le champ de l'allotransplantation de tissus composites (A.T.C.) en chirurgie reconstructrice. Les agents immunosuppresseurs sont devenus assez efficaces pour prevenir le rejet des greffons. Les premiers patients operes n'ont pas souffert de complication majeure ou irreversible de l'immunosuppression, mais certains effets secondaires potentiels restent un obstacle au developpement des allogreffes en chirurgie reconstructrice. Les premiers resultats fonctionnels des allogreffes sont encourageants mais leur evolution a long terme reste inconnue. Des phenomenes immunologiques (le rejet chronique) ou psychologiques (le refus du greffon ou de ses contraintes) pourraient degrader le resultat fonctionnel, esthetique et psychologique des allogreffes. Actuellement consideree comme une solution exceptionnelle pour des indications bien selectionnees, l'A.T.C. represente un formidable espoir pour l'avenir de la chirurgie reconstructrice.
Replacement versus adaptation investments and equity value

Abstract I examine the relative effects of replacement investments (RX) and adaptation investments (AX) on equity value. My analysis draws from the real-options theory that stresses the link between firm value and the option a firm holds to continue current practice or to adapt resources to new opportunities. The key prediction is that replacement and adaptation investments reflect the exercise of different investment options that have different implications for firm value; the effect of each investment type on firm value depends on the relative attractiveness of the underlying investment option. The results show that, in the presence of earnings, the effect of replacement investments on equity value is negative and increasing in earnings performance; by contrast, the effect of adaptation investments on equity value is positive and decreasing in earnings performance. Further analyses show that asset sales mediate the importance of adaptation investments in determining equity value.
Foraging Behavior of Pogonomyrmex owyheei in Southeast Idaho

Foraging behavior of Pogonomyrmex owyheei Cole was studied from 1977 to 1979 in Raft River Valley, Idaho. Average foraging distances were positively correlated with the estimated number of foragers per colony. Foraging trips took an average of 11.3 min, with 64% of this time spent in transit and 36% searching. Of the foragers, 75% returned with food, 21% with rock or debris, and 4% without a payload. Foraging ranges of individual colonies seldom overlapped, and aggressive encounters between ants of neighboring colonies were not observed. Concepts of territoriality may be unnecessary to explain space and resource partitioning among adjacent colonies of P. owyheei .
The social environment of the agitated nursing home resident

This study describes the characteristics of the social environment of 24 highly agitated and cognitively impaired nursing home residents, and the relationship between manifestations of agitation and attributes of the social environment. Results showed that the composition of the social environment of the agitated nursing home resident does not vary much with respect to time of day or day of the week. Additionally, most agitated behaviors were not generally affected by attributes of the social environment. The interaction of agitated behaviors with persons in the social environment is also examined. When agitated behaviors were directed towards someone, they were most likely to be directed towards staff members. Agitated behaviors were rarely triggered by any observable event, and few reactions to agitation were observed.
1,2,3-Thiadiazole: a novel heterocyclic heme ligand for the design of cytochrome P450 inhibitors.

The 1,2,3-thiadiazole heterocycle has been explored as a heme ligand and mechanism-based inactivator for the design of cytochrome P450 inhibitors. One 4,5-fused bicyclic and three 4,5-disubstituted monocyclic 1,2,3-thiadiazoles have been examined for their spectral interactions, inhibition, mechanism-based inactivation, and oxidation products by the versatile microsomal P450s 2B4, 2E1, and 1A2. The compounds generally show heteroatom coordination to the heme iron; however, the binding mode is influenced by the architecture of the active site. For example, 4,5-diphenyl-1,2,3-thiadiazole shows type I and type II difference spectra with P450s 2B4 and 2E1, respectively, and no spectral perturbation with P450 1A2. Except for the fused bicyclic compound, the spectral dissociation constants are in the 2−50 μM range. The effectiveness as an inhibitor depends on the substituents at the 4- and 5- positions and on the P450 examined. Inhibition of the P450-catalyzed 1-phenylethanol oxidation to acetophenone by the th...
Excitation Energy Transfer Pathways in Asymmetric Covalent Chlorophyll a Tetramers

We report the observation of multiple excitation energy transfer (EET) pathways in a covalently linked, chlorophyll (Chl) tetramer having three different fixed Chl−Chl distances. The tetramer was synthesized by covalently attaching 20-(4-ethynylphenyl)Chl to the 1,3,6,8-positions of pyrene to give Chl4-py. Reference Chl oligomers were prepared by attaching 20-(4-ethynylphenyl)Chl to the 1-position of pyrene (Chl-py), the 1,8 and 3,6 positions of pyrene (para-Chl2-py and ortho-Chl2-py, respectively), and the 1,3,5-positions of benzene (meta-Chl3). The Chlx-py derivatives were studied using femtosecond transient absorption (TA) and transient absorption anisotropy (TAA) spectroscopy, and compared with data obtained earlier on meta-Chl3. Using femtosecond TA, the decay of 1*Chl4-py was monitored after photoexcitation of its Qy band with a 655 nm, 130 fs laser pulse. A triexponential decay of 1*Chl4-py (τ = 7 ps, 152 ps, and 4.2 ns) was observed, with the two shorter time constants being laser intensity depend...
Magnetic resonance imaging in two dogs with central nervous system disease

Accurate localization of the lesions in two dogs with progressive neurological disease was demonstrated with magnetic resonance imaging (MRI). The first dog had unilateral cerebellar signs with associated paradoxical vestibular symptoms. The CSF tap and clinical localization suggested a right-sided cerebellar tumour and this was confirmed with MRI scanning. The second dog had predominantly asymmetrical fore-brain signs with circling, personality changes, seizures and contralateral proprioceptive deficits. CSF analysis suggested an inflammatory or neoplastic condition. MRI showed a diffuse oedematous lesion of the left cerebral hemisphere which corresponded exactly with the lesions seen at necropsy. The advantages of MRI over CT scans are discussed.
Scene-cut detection in image sequences using multiresolutional information features

This paper proposes to use a multiresolutional spatio- temporal metric for the segmentation of an image sequence. In particular, scene-cut detection performance from an image sequence will be furnished. Wavelet decomposition is used for the multiresolutional analysis. The segmentation results obtained here can be used in the video browsing and indexing in multimedia applications.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Architectural implications of daily life in ancient Tollán, Hidalgo, Mexico

Abstract Recent archaeological investigations at Tollan, Hidalgo, Mexico have produced evidence of a type of residential compound referred to as a house group. Two of these house groups are described architecturally, and inferences based upon the architectural data are made concerning the nature of the human groups that occupied them. The house groups are clearly domestic in nature and each housed a number of possibly related families; there is also evidence of economic and ritual specializations within these house groups. The architectural data further provides some insight into the general attributes of the house group as a mode of adaptation to urban life.
Genetic Counseling, Insurance Status, and Elements of Medical Home: Analysis of the National Survey of Children with Special Health Care Needs

Objective: To examine associations between receiving genetic counseling and the enabling factors of insurance and medical home. Methods: This study uses data from the National Survey of Children with Special Health Care Needs (CSHCN). We use descriptive statistics to characterize families of CSHCN who needed and received genetic counseling as well as families who needed but did not receive genetic counseling. We conduct logistic regression to calculate the association between receiving genetic counseling, insurance status, and medical home while adjusting for child’s age, mother’s education, race, ethnicity, and severity of condition. Results: Seven percent of families with CSHCN, representing 643,432 CSHCN nationwide, reported needing genetic counseling in 2001. Of those in need of genetic counseling, an estimated 123,117 CSHCN reported not receiving genetic counseling. Compared to CSHCN with continuous insurance coverage, CSHCN with interrupted insurance coverage and CSHCN without insurance are significantly less likely to receive genetic counseling. The odds of receiving genetic counseling by CSHCN with medical homes are 2.70 times higher compared to peers without medical homes (95% CI: 1.58, 4.61; p ≤ .001). Among the four elements comprising medical home in this study, family-centered care is the only element significantly associated with receiving genetic counseling. Conclusions: Our analysis presents evidence that receiving genetic counseling is positively associated with having continuous insurance coverage and receiving family-centered care. We discuss how researchers and policy makers may use these finding to explore strategies for improving care systems for CSHCN.
Influence of the percolation network geometry on electron transport in dye-sensitized titanium dioxide solar cells

Percolation theory is applied to understand the influence of network geometry on the electron transport dynamics in dye-sensitized nanocrystalline TiO2 solar cells, and the predicted results are compared with those measured by transient photocurrent. The porosity of the films was varied experimentally from 52 to 71%. Electron transport was modeled using simulated mesoporous TiO2 films, consisting of a random nanoparticle network, and the random-walk approach. The electron transport pathway through the network was correlated with the film porosity and the coordination numbers of the particles in the film. The experimental measurements and random-walk simulations were in quantitative agreement with percolation theory, which predicts a power-law dependence of the electron diffusion coefficient D on the film porosity as described by the relation: D ∝ |P − Pc|μ. The critical porosity Pc (percolation threshold) and the conductivity exponent μ were found to be 0.76 ± 0.01 and 0.82 ± 0.05, respectively. The frac...
Kinematic analyses over eastern Asia during a subperiod of the air mass transformation experiment 1975

This study examines the large-scale vorticity and vertical motion fields over eastern Asia during a subperiod (13–16 February) of the Air Mass Transformation Experiment (AMTEX) 1975. This represents a period of cyclogenesis and subsequent formation of mesoscale cellular convection (MCC) over the AMTEX region. Vertical motion and vorticity fields reflect the developing cyclone and a short synoptic-scale upper wave which propagated across the computational region. Results for the AMTEX region reveal that during MCC occurrences large-scale downward motion and a change from negative to positive vertical gradient of vorticity in the lower troposphere occur. DOI: 10.1111/j.2153-3490.1977.tb00750.x
Metabolism of O,S-dimethyl propionyl- and hexanoylphosphoramidothioate in the house fly and white mouse

Abstract The metabolism of O,S -dimethyl propionyl- and hexanoylphosphoramidothioate was investigated in the white mouse and house flies. Compared to the hexanoylphosphoramidothioate, the propionyl analog is approximately 35-fold more toxic to house flies and is 10-fold less toxic to mice. On a percentage basis, substantially larger amounts of methamidophos were detected in house flies treated topically with the propionylphosphoramidothioate than in flies treated with the hexanoyl derivative. The reverse was evident in the case of the mouse where much larger amounts of methamidophos were formed after oral treatment with the hexanoylphosphoramidothioate. Minor amounts of other metabolic products also were detected, including an unknown from the hexanoylphosphoramidothioate. Metabolism of the S -methyl moiety to carbon dioxide appeared to be a major pathway for metabolic degradation of both compounds in both the white mouse and house fly. The difference in toxicity of the two acylphosphoramidothioates to the mouse and house fly is attributed to difference in the amounts of methamidophos formed in the animals.
Specificity and mechanisms of gymnemic acid antagonism (inhibition)

In her letter, Kennedy had several objections to our recent review of our conclusions about the effects of gymnemic acid (GA) on the mammalian sugar taste response (Jakinovich and Sugarman, 1988). Because our review focus was confined to the mammalian taste response, we will not address objections concerning insects or amino acids. In our response letter, we will only address the objections concerning the specificity and mechanism of GA antagonism (inhibition) of the mammalian sugar taste response
Activation of the JNK/SAPK and P38 Mitogen-Activated Protein Kinase Signaling Pathways Sensitize Tumor Cells to Cisplatin-Induced Apoptosis

INTRODUCTION. Chemoresistance is a major impediment to the successful treatment of cancer. However, the mechanisms of chemoresistance are poorly understood. Cisplatin (CDDP) treatment activates multiple signal transduction pathways that can lead to diverse cellular responses, including cell cycle arrest (G2/M), DNA repair, or apoptosis. Differences in early signal transduction activity in response to chemotherapy could provide insight regarding the ultimate outcome of treatment. In this study, we attempted to elucidate the mechanisms of resistance to cisplatin in a cisplatin-sensitive human ovarian cancer cell line and a cisplatinresistant clone (2008 and 2008.C13 respectively).
Are HMO physicians more price sensitive in prescribing brand‐name drugs?

Purpose – The purpose of this paper is to estimate whether health maintenance organizations (HMO) physicians are more price sensitive than non‐HMO physicians in their prescribing behavior of brand‐name substitutes.Design/methodology/approach – The study uses physician level data and a set of 13 drugs for the years 1997‐2000 to estimate the price sensitivity of HMO and non‐HMO physicians. A two‐part model is used to measure the price elasticity of brand‐name prescribing for HMO physicians. The first part uses a logit model to examine the physician's choice to prescribe the same drug to all patients with the same medical condition, or whether physicians alternate prescriptions among brand‐name substitutes. The second part employs OLS to estimate the influence of managed care, i.e. HMOs, on physician price sensitivity.Findings – The results suggest that HMO physicians are less likely than non‐HMO physicians to prescribe a common drug to all patients with a specific medical condition, but rather HMO physician...
Mathematical modeling of topotecan pharmacokinetics and toxicodynamics in mice.

The objective of this study was to investigate the pharmacokinetics and toxicodynamics of topotecan (TPT) in mice and to develop an integrated pharmacokinetic/toxicodynamic (PK/TD) model to characterize the relationship between the time course of TPT disposition and the time course of TPT-induced toxicity. TPT was administered to groups of 3–5 mice via i.v. bolus injection, i.p. bolus injection, and by i.p. infusion over 24, 72 and 168 h. Body weight was monitored to assess TPT-induced toxicity, and serial blood samples were collected and analyzed via HPLC to assess TPT pharmacokinetics. We found that TPT-induced toxicity increased dose-dependently for each mode of dosing investigated. The time course of topotecan-induced body weight-loss was delayed relative to the time course of topotecan disposition; nadir body weight was observed as late as 6 days following i.p. bolus dosing, and 3–5 days following termination of i.p. infusion. TPT exhibited non-linear disposition, which was well-characterized through the use of a two-compartment model with saturable elimination from the central compartment. Toxicodynamic data were characterized with an integrated PK/TD model that incorporated an indirect-effect model and four transit compartments to describe transduction events associated with TPT-induced toxicity. This model will be used to support the development of an inverse-targeting strategy that aims to enhance topotecan safety and efficacy.
Microwave measurements in the N.B.S. Electronic Calibration Center

In the Electronic Calibration Center of the National Bureau of Standards Radio Standards Laboratory, Boulder, Colorado, work is proceeding towards the establishment or extension of calibration services over a broad range of frequencies in the microwave region. At the present time, measurements can be made over limited portions of the frequency spectrum for the quantities of low-level c.w. power, reflection coefficient, frequency and attenuation. Calibration services are currently provided for all of these quantities. Instrumentation for the measurement of microwave noise is near completion. A survey is given of the microwave measurement techniques employed in this work.
Calorimetric determination of the enthalpy of ionization of oxidized and reduced horse heart cytochrome c

The heats of ionization of protons, ΔHi, of oxidized and reduced horse heart cytochrome c in 0.15M KCl at 20°C were determined using a titration calorimeter which simultaneously afforded the potentiometric titration curve. Reproducibility of the thermal titrations is within 2%, and evaluation of the heats observed after the heat loss corrections is estimated to be within 5%. A single titration of oxidized cytochrome c from pH 11 to 3 is in excellent agreement with the thermal titration of this protein obtained with flow calorimetry. The thermal titration, however, is not reversible, due in part to the loss of titratable group(s) in this pH region and to the heat contribution of the acid and alkaline conformational changes which occur. Although of lesser magnitude, the reduced form also indicates similar thermal transitions. These differences are due solely to conformational contributions to the thermal process, since the potentiometric curves are reversible. The nature of the irreversibility for oxidized cytochrome c appears to involve the loss of a group with pK′ 8.9 and the shift of two groups from pK′ 5.6 to 4.8. Thermal difference curves for this process indicate that heats of −7.8 and −24.1 kcal/mol are liberated which are centered at pH 9.3 and 3.9, respectively.
International network of treatment alternatives for recovery – INTAR

The International Network of Treatment Alternative for Recovery (INTAR; http://www.intar.org) was founded in 2003 by a group of U.S. practitioners and advocates in mental health recovery including world renowned psychiatrists, people who have recovered from mental distress, psychologists, family members and other mental health professionals. The international organization grew out of the shared experience and expert body of research that demonstrates a strong need to promote non-medical humane, non-coercive ways of helping people in emotional crisis. INTAR is a key international organization dedicated to advancing the knowledge and availability of alternative approaches for individuals experiencing severe mental distress. This presentation will focus on strategies to increase the knowledge base about effective, non-coercive alternatives and to promote their dissemination.
Using peer-to-peer technology for collaborative knowledge management: concepts, frameworks and research issues

As organizations struggle with how to develop and use their inherent expertise, the importance of knowledge management and collaboration has grown in both academic and practitioner communities. This paper outlines a new concept of collaborative knowledge management (CKM), which bridges the two fields. Drawing from literature, we present a conceptual framework for understanding the concepts underlying CKM. Next, this paper explores how a new technology, peer-to-peer (P2P), fits in the CKM paradigm. A discussion on P2P tools and a comparison of these tools with client server tools for enabling the CKM process is presented. P2P has great appeal for CKM because it allows people to work in a more natural fashion. As technology and practitioners needs evolve, it is important to recognize the existence of various CKM levels in the organization. This paper outlines a framework recognizing five different levels. The final section of the paper identifies research themes concerning the use of P2P applications for CKM both within each of the levels and across levels.
What impact does a specialized center for transplantation and heptobiliary disease have on post-graduate resident training of gastroenterologists and surgeons?

What impact does a specialized center for Hepatobiliary disease and transplantation have on the training of general Gastroenterologists and Surgeons? Currently, the postgraduate medical training environment in the United States is in tremendous evolution. Many changes are already common practice in the European community. In July 2003, guidelines regarding trainee work-hours and programmatic curricular topics became requirements for continued accreditation by the Accreditation Council for Graduate Medical Education (ACGME) in the United States. In order to ensure efficient resident education and compliance with work-hour guidelines, trainee clinical rotations are assigned more for the educational value of the clinical experience versus ‘service’ requirements for house staff. Due to limited work hours, training programs must now be meticulously organized in order to cover mandatory topics in a shorter time period. More burden is being placed on the house officer to supplement his or her clinical exposure with independent study and readings when not in the hospital [1]. Traditional models of immersion learning in academic medical centers, where large volumes of patients are cared for, is being re-examined. The current trend in post-graduate residency training is to expose the trainee to broad-based clinical training with limited numbers of patients [2] which often leaves the trainee ill-equipped to handle intricate and complicated disease states in an individual patient. With the increasing technological advances, sophistication of antiHepatitis therapy and complexity of patients with liver disease requiring operative and/or medical interventions, specialized Transplant/Hepatobiliary centers, or disease specific centers, are alternatives to care for these types of patients. Other specialties such as Cardiology and Cardiac Surgery, Neurology, Orthopedics and Ophthalmology have established specialized free-standing hospitals or disease specific centers within traditional academic medical settings with demonstrable improvement in efficiency in patient
Phase transition of DNA-linked gold nanoparticles

Abstract Melting and hybridization of DNA-capped gold nanoparticle networks are investigated with optical absorption spectroscopy. Single-stranded, 12-base DNA-capped gold nanoparticles are linked with complementary, single-stranded, 24-base linker DNA to form particle networks. Compared to free DNA, a sharp melting transition is seen in these networked DNA-nanoparticle systems. The sharpness is explained by percolation transition phenomena.
Surface analysis of Ln2−xCexCuO4 (Ln = Pr and Nd) single crystals grown by the top seeded solution method

Large single crystals of Ln2−xCexCuO4 (Ln = Pr and Nd), of the average size of approximately 5 mm × 5 mm × 1 mm, were grown by the top seeded solution growth (TSSG) technique. The optical constants of the crystals were determined by variable angle spectroscopic ellipsometry (VASE) and the results seem to indicate that a 1.5 eV absorption peak appears in the undoped material and is weakened and shifted downward in energy upon annealing. The compositions and crystal structure were examined using rutherford backscattering spectroscopy (RBS) with ion beam channeling. Also, the effect of annealing on the crystalline structure was probed by ion beam channeling. The orientation and lattice parameters of the crystals were determined by X-ray diffraction and the superconductivity of the specimens was monitored using a SQUID magnetometer. The results indicate that the crystals grown by the TSSG method are very uniform in composition and well-oriented. However, analysis of the RBS data indicated up to 1% Pt inclusion in the crystals from contact with the Pt crucibles. The inclusion of Pt acted to quench the superconducting transition temperatures and Pt was found to substitute for Cu.
Analysis of the spectrin binding domains of globin

This study describes the results of binding studies between human spectrin and peptides obtained by trypsin digestion of human globin. The globin digest when passed through an affinity column of spectrin-coupled sepharose retained one peptide from both alpha and beta chains of globin. The absorbed peptides were eluted with 4 M guanidine hydrochloride and separated on a reverse phase column by high pressure liquid chromatography. Their amino acid sequence was determined and their position located in the globin molecule.
The effects of changeover delays of fixed or variable duration on concurrent variable-interval performance in pigeons

The effects of changeover delays of fixed or variable duration on concurrent variable-interval performance in pigeons were investigated in a series of three experiments. Experiment 1 compared the effects of a fixed, variable, or variable signaled changeover delay on interchangeover times and responding during and after the changeover delay. The duration of the changeover delays was systematically varied in Experiment 2, and the relative reinforcement frequencies were manipulated in Experiment 3. Interchangeover times were found to be shorter when changeover delays of variable duration were compared with those of fixed duration. Changeover delays of fixed duration produced higher response rates during the changeover delay than after the changeover delay had elapsed; changeover delays of variable duration produced such differences to a lesser extent. It was concluded that the changeover delay in concurrent variable-interval schedules of reinforcement functionally acts as a delay period to the next opportunity for reinforcement, possibly serving as a conditioned reinforcer for the behavior preceding it (the interchangeover time) and as a discriminative stimulus for the behavior in its presence (response rates during the delay).
Long-range alpha detector (LRAD) technology, results, and applications

The usefulness of traditional alpha detectors for contamination monitoring is limited by the size and sensitivity of the detectors and by the short range of alpha particles in air. The long-range alpha detector (LRAD) detects the ions produced by the alpha particles passing through air, rather than the alpha particles themselves. Thus, LRAD detection is limited by the range of the ions (tens of meters), rather than the range of the alpha particles (a few centimeters). Since it collects all ions simultaneously, an LRAD monitor will be sensitive to all of the sources of contamination contained within it. In addition, the electronic noise within the LRAD can be reduced so that better sensitivity than that of traditional detectors is possible. Both soil surface and object monitors incorporate these advantages in their designs. Field-test results for these monitors are discussed. >
Metamorphic changes in haemolymph and midgut proteins of the southwestern corn borer, Diatraea grandiosella☆

Abstract Haemolymph and midgut proteins of the southwestern corn borer, Diatraea grandiosella, were studied for developmental changes and possible relationships at the onset of metamorphosis. The protein content of both tissues was found to increase markedly during the last two larval instars before falling sharply during the pharate pupal stage. However, a comparative study of their rates of protein biosynthesis revealed that, unlike midgut cells, larval haemocytes were unable rapidly to synthesize protein. Further electrophoretic results indicated that midgut cells, like those of the larval fat body, have the potential to synthesize at least the two major haemolymph proteins. The observed decrease in protein content of the haemolymph during the pharate pupal stage could be partially attributed to the uptake of at least one of its proteins by the fat body. The origin and fate of haemolymph proteins in metamorphosing insects are discussed.
Litter sex composition affects life-history traits in yellow-bellied marmots

Summary 1. The presence of siblings might have long-lasting fitness consequences because they influence the early environment in which an animal develops. Several studies under laboratory conditions have shown long-lasting consequences from the presence of male siblings in utero on morphology and life-history traits. However, in wild animals, such effects of litter sex composition are unexplored. 2. We capitalized on a long-term study of individually marked yellow-bellied marmots (Marmota flaviventris) and documented the effects of weaned litter sex composition and anogenital distance on several life-history and fitness traits. 3. First, we demonstrated that the number of males in a litter influenced anogenital distance. Then, we found that masculinized females, those with larger anogenital distances, were less likely to survive their first hibernation, were more likely to disperse and were less likely to become pregnant and wean young. Males from male-biased litters had lower growth rates, but we failed to detect longer-term consequences. 4. Taken together, our results show profound sex-dependent effects of litter sex composition, probably due to differential prenatal exposure to androgens, in free-living animals. We conclude that masculinization might constitute an alternative mechanism explaining variation in different demographic traits. This finding highlights the importance of studying these maternal effects, and they enhance our concern over the widespread use of endocrine disrupting compounds.
A model of the chemistry in cometary comae: deuterated molecules

ABSTRA C T We have developed a combined chemical and hydrodynamical model of cometary comae. The model is described and used to follow the deuterium chemistry occurring in the coma after the sublimation of D-rich nuclear ices. It is shown that the molecular D/H ratios in parent species remain unchanged in the coma gas, confirming that observations of such molecules can be used to infer the D/H ratio in the nuclear ices. The D/H ratios in daughter molecules reflect that of their parents, and so can potentially be used to elucidate the formation mechanisms of these species. In particular, observations of DNC may be able to resolve the uncertainty surrounding the origin of HNC in cometary comae.
Effects of the H 3 antagonist, thioperamide, on behavioral alterations induced by systemic MK-801 administration in rats

Rationale Recent studies have raised the possibility that antagonists of H3 histamine receptors possess cognitive-enhancing and antipsychotic properties. However, little work has assessed these compounds in classic animal models of schizophrenia.
Cocaine withdrawal enhances long‐term potentiation induced by corticotropin‐releasing factor at central amygdala glutamatergic synapses via CRF1, NMDA receptors and PKA

Cocaine addiction is an enduring, relapsing, behavioural disorder in which stressors reinstate cocaine-seeking even after prolonged abstinence. Evidence suggests that the 'anxiety-like' behaviour and stress associated with protracted withdrawal may be mediated by increased corticotropin-releasing factor (CRF) in the central nucleus of the amygdala (CeA), a part of the limbic circuitry engaged in the coding and transmission of stimulus-reward associations. In the present study we describe a long-lasting potentiation of glutamatergic transmission induced at lateral amygdala (LA)-to-CeA synapses by rat/human CRF. After 2 weeks of withdrawal from repeated intermittent exposure to cocaine, CRF-induced long-term potentiation (LTP) was greatly enhanced compared to the respective saline control group while, after short-term withdrawal (24 h), there was no significant difference between the two treatment groups, indicating alterations in CRF systems during protracted withdrawal from chronic cocaine. After prolonged withdrawal, CRF-induced LTP was dependent on activation of CRF 2 , Cav2.3 (R-type) calcium channels and intracellular signalling through protein kinase C in both saline- and cocaine-treated groups. The enhanced CRF-induced LTP after 2 weeks of withdrawal was mediated through augmented CRF 1 receptor function, associated with an increased signalling through protein kinase A, and required N-methyl-D-aspartate (NMDA) receptors. Accordingly, single-cell recordings revealed a significantly increased NMDA/AMPA ratio after prolonged withdrawal from the cocaine treatment. These results support a role for CRF 1 receptor antagonists as plausible treatment options during withdrawal from chronic cocaine and suggest Cav2.3 blockers as potential candidates for pharmaceutical modulation of CRF systems.
Performance simulation of nanoscale silicon rod field-effect transistor logic

We have simulated the behavior of a rod shaped nanoscale ring-gated field-effect transistor (RG-FET) using the PISCES-IIb semiconductor drift-diffusion solver. The results from these simulations are used by a customized SPICE 3f5 kernel to simulate several simple logic gates. The usefulness of this kind of transistor is examined within the context of a self-assembling fabrication technique that we outline.