cssi/SciSciGPT-SciSciNet huggingface dataset:
A modal logic for role-based access control

Making correct access-control decisions is central to security, which in turn requires accounting correctly for the identity, credentials, roles, authority, and privileges of users and their agents. In networked systems, these decisions are made more complex because of delegation and differing access-control policies. Methods for reasoning rigorously about access control and computer-assisted reasoning tools for verification are effective for providing assurances of security. In this paper we extend the access-control logic of [11,1] to also support reasoning about role-based access control (RBAC), which is a popular technique for reducing the complexity of assigning privileges to users. The result is an access-control logic which is simple enough for design and verification engineers to use to assure the correctness of systems with access-control requirements but yet powerful enough to reason about delegations, credentials, and trusted authorities. We explain how to describe RBAC components such as user assignments, permission assignments, role inheritance, role activations, and users' requests. The logic and its extensions are proved to be sound and implemented in the HOL (Higher Order Logic version 4) theorem prover. We also provide formal support for RBAC's static separation of duty and dynamic separation of duty constraints in the HOL theorem prover. As a result, HOL can be used to verify properties of RBAC access-control policies, credentials, authority, and delegations.
Experiencing Venus: Clues to the origin, evolution, and chemistry of terrestrial planets via in-situ exploration of our sister world

We review the current state of knowledge of (1) the origin and evolution of Venus and (2) the photochemical and thermochemical processes occurring in the middle and lower atmosphere there. For each, we review the promise of on-going and planned orbital observations by ESA's Venus Express and Japan's Venus Climate Orbiter missions. We review the need for future in-situ measurements for understanding Venus origin and evolution and present-day chemistry, and the implications for understanding the origin and history of the Earth and other bodies in the inner solar system, as well as for understanding terrestrial planets in other solar systems. We prioritize the goals remaining in the post Venus Express era, based on the Decadal Survey (National Research Council, 2003). Using past experience with Pioneer Venus, VEGAs, Veneras, and, most recently, Venus Express as guides, we suggest appropriate techniques and measurements to address these fundamental science issues.
"El Agua No Se Vende: Water is Not For Sale!" The Latin American Water Tribunal as a Model for Advancing Access to Water

Nestled in the mountains of central Mexico, the tight-knit community of indigenous Mazahua people had remained relatively unaltered by the changes taking place in the rest of the world. The Mazahua Indians remained this way until the Mexican government created the oppressive water regime known as the Cutzamala System, which shipped water from Mazahua lands to the capital, Mexico City. Now, the Mazahua people are in constant conflict with the Mexican government and in constant struggle to survive. Mexico City needs water for the booming metropolis. The Mazahua people live in a region with copious natural water resources. The powerful Mexican government commandeers the water from the Mazahua
Protein kinase C regulation of dopamine transporter initiated by nicotinic receptor activation in slices of rat prefrontal cortex

We previously reported that activation of nicotinic receptors causes an enhancement in amphetamine-stimulated release of dopamine via its transporter from slices of prefrontal cortex, but no such enhancement of release from slices of nucleus accumbens or striatum. The nicotinic receptors mediating the enhancement most likely contain α4 and β2 subunits based upon pharmacological characterization. In this study, we sought to characterize the second messenger systems associated with the nicotine-mediated response. Sodium channel involvement was confirmed by the observation that tetrodotoxin blocked nicotine-mediated enhancement, whereas veratridine or elevated K+ mimicked the enhancement seen with nicotine. Inclusion of EGTA blocked nicotine-mediated enhancement, suggesting that, even though no exogenous Ca2+ was added, endogenous stores were required for the enhancement. The enhancement by nicotine was also abolished by the L-type voltage-dependent calcium channel (VDCC) antagonist nitrendipine, but not by the N-type VDCC antagonist ω-conotoxin GVIA. Finally, inhibition of protein kinase C also abolished the nicotine-mediated enhancement of amphetamine-stimulated dopamine release, whereas inhibitors of Ca2+/calmodulin kinase II did not. These findings establish that nicotine can exert selective effects on dopamine transporter activity in prefrontal cortex, an area involved in cognition and learning.
The impact of sustainable governance and practices on business performance: an empirical investigation of global firms

In a globally-competitive market, can sustainable policies and operations sustain business performance? Considering the current substantial focus on sustainable practices in companies around the world, this study investigates the effects of sustainable practices on overall business performance. This research forwards a hypothesised framework that traces interlinkages between sustainability governance, supply chain (SC) operations and business performance followed by a time-lagged empirical investigation using archival data for Fortune-100 global environmentally-sustainable companies in line with World Summit on Sustainable Development (WSSD) green productivity measures. The study surprisingly reveals the disparity in translating governance policies in sustainable SC practices and dismal direct effects of sustainable SC practices on business performance. However, lackluster direct effects are mitigated by institutionalised sustainable reporting transparency that positively impacts overall business performance, highlighting the imperative role of sustainability reporting as a prerequisite to financial performance in a global market.
Graduate Medical Education: Issues and Options

Frank C. Wilson. Oxford: Radcliffe Publishing; 2009. 136 pages. $49.00. ISBN: 978-1-84619-378-1. The monograph Graduate Medical Education is about the current status of graduate medical education in the United States, and the Issues and Options rejoinder is the author’s assessment of the future of graduate medical education. Written by Frank C. Wilson, MD, a master orthopaedic surgeon and educator, this work is for a wider audience than orthopaedic surgeons. The intended readership includes orthopaedists who are involved with the education and training of residents and/or the administration of programs that support orthopaedic training. This book will also bring much needed information to surgeons who are curious about the graduate medical education system, shedding light on topics that are often not visible to those who …
From Cheerleader to Coach: The Developmental Progression of Bedside Teachers in Giving Feedback to Early Learners.

BackgroundMedical students learn clinical skills at the bedside from teaching clinicians, who often learn to teach by teaching. Little is known about the process of becoming an effective clinical teacher. Understanding how teaching skills and approaches change with experience may help tailor faculty
The Effect of a Vitamin A Acetate Diet on Ultraviolet Radiation–induced Immune Suppression as Measured by Contact Hypersensitivity in Mice†¶

The adverse health effects caused by increased exposure to ultraviolet radiation (UVR) due to deterioration of stratospheric ozone are of major concern. These health effects include sunburn, skin cancer, cataracts and immune suppression. Immune suppression has been associated with the release of cytokines, a defect in antigen presentation, induction of suppressor T cells and suppression of contact hypersensitivity (CH). CH is typically assessed by the mouse ear swelling test (MEST). Previous studies have demonstrated enhanced CH responses with vitamin A acetate (VAA) dietary supplementation assessed by MEST and the local lymph node assay (LLNA). To determine the effect that VAA has on UVR-induced immune suppression, we examined both the induction and elicitation phases of CH using murine models. The MEST was used to evaluate the interaction of UVR and VAA on CH elicitation. However, a positive MEST response requires that the induction phase as well as the elicitation phase of CH be functional. The LLNA was used to evaluate the interaction of UVR and VAA only on CH induction. We tested the hypothesis that mice maintained on a VAA-enriched diet are more resistant to UVR-induced immune suppression (CH) than those maintained on a control diet. Mice were maintained on a VAA-enriched or the control diet for 3 weeks and then exposed to UVR 3 days prior to sensitization with 2,4-dinitrofluorobenzene (DNFB). VAA enhanced the MEST response in both UVR-exposed and non-UVR-exposed mice. The VAA-enriched diet did not significantly alter the LLNA response in either UVR- or non-UVR-exposed mice. However, there was significant suppression in CH by UVR as measured by the LLNA. These results indicate that (1) the VAA-enriched diet does not restore the number of proliferating cells in the CH induction phase of UVR-induced immunosuppression; (2) the immunosuppressive effects of UVR affect the induction phase of CH; and (3) the LLNA should be examined as an alternative to the MEST for measurement of UVR-induced immunosuppression. The data indicate that the VAA-enriched diet enhanced the elicitation response (MEST) but not the earlier induction phase (LLNA). Further studies are necessary to define mechanisms of action, but modulation of cytokines and effects of specific lymphocyte subsets, as well as systemic effects and local modulation at the site of elicitation are possible. Additionally, future studies to evaluate the effect of the VAA-enriched diet when multiple doses of both UVR and DNFB are used would be of interest for both the LLNA and MEST end-points.
Role of Cell Cycle Regulatory Proteins in Cerebellar Granule Neuron Apoptosis

Cerebellar granule neurons (CGNs) undergo apoptosis when deprived of depolarizing concentrations of KCl, but the underlying molecular mechanisms are not yet clear. Although caspases have been postulated to be involved in CGN cell death, inhibitors of caspases failed to prevent apoptosis under our culture conditions, suggesting an involvement of other molecules and pathways. We find that inhibitors of cyclin-dependent kinases—flavopiridol, olomoucine, and roscovitine—protect CGNs from KCl withdrawal-induced apoptosis, suggesting that cell cycle components play a significant role in the death of these neurons. Analysis of the different cell cycle regulatory elements in this model revealed that apoptosis is preceded by an increase in the level of cyclin E protein, with elevated nuclear levels of cyclin D1 and with enhanced activity of the cyclin D1- and E- associated kinases. In addition, there was a significant decrease in the level of the cyclin-dependent kinase (cdk) inhibitor p27. In agreement with these changes, analysis of a major substrate of cyclin-activated cdks, retinoblastoma protein (Rb), showed an increase in the level of phosphorylated forms within 1 hr of KCl withdrawal. Moreover, the overall levels of Rb protein were significantly reduced within 6–12 hr of KCl withdrawal and did so by a caspase-independent mechanism. All of these responses were blocked by cdk inhibitors. These findings indicate that cdks act at an early step in the pathway by which KCl withdrawal induces apoptotic death of cerebellar granule cells and suggest that additional elements of the cell cycle machinery participate in this mechanism.
The use of curvilinear fiber format to improve buckling resistance of composite plates with central circular holes

The gains in buckling performance are explored that can be achieved by deviating from the conventional straightline fiber format and considering the situation whereby the fiber orientation in a layer, or a group of layers, can vary from point to point. The particular situation studied is a simply supported square plate with a centrally located hole loaded in compression. By using both a sensitivity analysis and a gradient-search technique, fiber orientation in a number of regions of the plate are selected so as to increase the buckling load relative to baseline straightline designs. The sensitivity analysis is used to determine which regions of the plate have the most influence on buckling load, and the gradient search is used to find the design that is believed to represent the absolute maximum buckling load for the conditions prescribed. Convergence studies and sensitivity of the final design are discussed. By examining the stress resultant contours, it is shown how the curvilinear fibers move the load away from the unsupported hole region of the plate to the supported edges, thus increasing the buckling capacity. The tensile capacity of the improved buckling design is investigated, and it is shown that both tensile capacity and buckling capacity can be improved with the curvilinear fiber concept.
Hemodynamic and renin responses to (±)-DOI, a selective 5-HT2 receptor agonist, in conscious rats

Abstract The effect of the selective 5-HT2 agonist (±)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane HCl (DOI) on arterial pressure (AP), heart rate (HR), renal blood flow (RBF) and plasma renin activity (PRA) was determined in conscious rats. DOI increased AP and PRA, but decreased HR and RBF. All responses to DOI were abolished by central (LY 53857) or peripheral (xylamidine) 5-HT2 antagonists. Prazosin did not alter the AP or HR response to DOI. Chlorisondamine abolished the bradycardia but slightly increased the hypertension produced by DOI, while enalapril attenuated the pressor response. No further reduction was produced by the combination of enalapril and prazosin. Propranolol attenuated but did not eliminate the renin response, and blocked the bradycardia elicited by DOI. The data suggest that DOI activates 5-HT2 receptors located on vascular smooth muscle and/or the circumventricular organs of the brain to: (1) increase AP and reflexly decrease HR, (2) decrease RBF and (3) increase PRA. The hypertension is mediated by angiotensin II and direct vascular effects whereas the increase in PRA is mediated by an interaction of increased sympathetic nerve activity and decreased renal perfusion pressure.
Research Note: An Error Correction Analysis of Visitor Arrivals in the Bahamas:

Tourism is a major activity for many countries in the Caribbean. Accurate forecasts of visitor arrivals can assist planning efforts in the public and private sectors. This study uses error correction models (ECMs) to analyse visitor arrivals in the Bahamas. Findings suggest that income and habit persistence/word-of-mouth advertising are primary determinants of tourism to the Bahamas, while the cost of travel is generally insignificant. To assess the model reliability further, ECM forecasts are compared to random walk and random walk with drift benchmarks. The ECMs provide fairly reliable forecasts, but are less accurate than the benchmarks.
Motivations to Serve: The Soviet Soldier in the Second World War

This article argues that the willingness of the average Soviet citizen to serve in the armed forces in the Second World War, which enabled the Red Army and the Soviet Union to survive the calamities of 1941 and then defeat the German invasion, was based on the socialist ideals of the Stalinist state, a patriotic love for the historic Russian motherland that transcended politics, and a variety of other social and personal reasons, as well as fear of the consequences of draft evasion and desertion. Service, however, was not an endorsement of the oppression of the Stalinist state.
Comprehensive MMF–MFL inspection for corrosion detection and estimation in embedded prestressing strands

This paper describes the development of a magnetic sensor system for the evaluation of the condition of prestressed strands inside the bottom layer of concrete box beams. The sensor consists of an electromagnet which magnetizes embedded prestressing strand and measures the magnetic field response of the strands using Hall sensors embedded at different positions on the electromagnet. The novel aspect of this comprehensive system is the integration of measuring magnetic flux leakage (MFL) and main magnetic flux (MMF) signals. A computer-aided simulation model has also been developed to use these signals in estimating corrosion. The MFL signal gives indications of the presence of corrosion and cracks or fractures in the strands. The MMF signal quantifies the amount of steel loss in the strands due to corrosion or rusting. Both these techniques have been independently evaluated using magnetic inspection systems which made them suitable to be used in a single sensor system. This comprehensive system was evaluated in a laboratory setting to identify corrosion and strand breaks in prestressing strands. It was observed that the MFL signal could identify the presence of corrosion and strand breaks, while the MMF signal could be used to estimate the loss of steel due to corrosion. This system was also evaluated using it in an inspection of decommissioned prestressed box beams removed from Ohio’s oldest prestressed box-beam bridge. The findings from this inspection revealed a good match with the dissected areas of the box beams. Steps to move the system to implementation are also discussed. With further development improving the accuracy of this inspection system, it can become a valuable tool to bridge engineers for box-beam inspection.
Intermediate coupling collision strengths for Δn = 0 transitions produced by electron impact on highly charged He- and Be-like ions☆

Coulomb--Born-exchange data for intermediate coupling scaled collision strengths Z/sup 2/..cap omega.. for all fine-structure transitions of type 2l/sub a/2l/sub b//sup 2S//sub a/+1L/sub a//sub J/a -2l'/sub a/2l'/sub b//sup 2S/'/sub a/+1L'/sub a//sub J/'/sub a/ in Be-like ions with 12 < or =Z< or =74 and the kind 1s2l/sub b//sup 2S//sub a/+1L/sub a//sub J/a -1s2l'/sub b//sup 2S/'/sub a/+1L'/sub a//sub J/'/sub a/ in He-like ions with 6< or =Z< or =74 are fitted by simple functions of the impact electron energy epsilon in threshold units. To obtain collision rates these functions can be readily integrated over a Maxwellian distribution for the electrons. Fits to the data for transitions between energy terms are also included. In addition results are given for the transition energies and the electric-dipole radiative line strengths. The basic collision strength data cover impact electron energies less-than-or-equal-tilde3.25 Z/sup 2/ Ry or 44.3 Z/sup 2/ eV.
Repair of an Alar Defect

A healthy, 44-year-old white man was referred for Mohs micrographic surgery of a biopsy-proven basal cell carcinoma of the left ala. At presentation, the patient had a nodular plaque measuring 0.6×0.5 cm with ill-defined clinical borders of the left ala. Given the critical anatomic location and ill-defined borders, Mohs micrographic surgery was indicated. The tumor was subsequently extirpated in two stages using the Mohs technique producing a surgical defect measuring 1.4×1.0 cm in greatest dimension. The resultant sur-gical defect extended into the subcutaneous tissue of the left ala but did not perforate into the nasal vesti-bule (Figure 1). Reconstructive options considered included second intention healing, full-thickness skin graft, composite graft, island pedicle flap, and a two-stage interpolation flap. As a dermatologic surgeon, how would you address this patient's surgical defect to yield the optimum functional and aesthetic restoration? Figure 1. Download figure to PowerPoint
Tailoring click models to user goals

Click models provide a principled way of understanding user interaction with web search results in a query session and a statistical tool for leveraging search engine click logs to analyze and improve user experience. An important component in all existing click models is the user behavior assumption -- how users scan, examine and click web documents listed in the result page. Usually the average user behavior pattern is summarized in a small set of global parameters. Can we fit multiple models with different user behavior parameters on a click data set? A previous study showed that the mixture modeling approach did not lead to better performance despite extra computational cost.In this paper, we present how to tailor click models to user goals in web search through query term classification. We demonstrate that better predicative power could be achieved by fitting two click models for navigational queries and informational queries respectively, as evidenced by the likelihood and perplexity evaluation results on a subset of the MSN 2006 RFP data which consists of 121,179 distinct query terms and over 2.8 million query sessions. We also propose search relevance score (SRS) as a flexible evaluation metric of search engine performance. This metric can be derived as summary statistics under any click model, and is applicable to a single query session, a particular query term and the search engine overall.
Maintaining availability in partitioned replicated databases

In a replicated database, a data item may have copies residing on several sites. A replica control protocol is necessary to ensure that data items with several copies behave as if they consist of a single copy, as far as users can tell. We describe a new replica control protocol that allows the accessing of data in spite of site failures and network partitioning. This protocol provides the database designer with a large degree of flexibility in deciding the degree of data availability, as well as the cost of accessing data.
Abstract 1240: Bioactive proanthocyanidins from grape seeds inhibit cigarette smoke condensate-enhanced invasion of human non-small cell lung cancer cells by targeting NADPH oxidase and epithelial-mesenchymal transition

Lung cancer is the leading cause of cancer-related deaths in the United States, and the dismal 5-year survival rate of approximately 14% has shown no improvement over the past three decades. Cigarette smoke (CS) is the cause of ∼90% of lung cancer cases, and promotes drug resistance in lung cancer patients and is even known to limit effectiveness of treatment of cancers of other organs. It is therefore important to develop more effective strategies targeting CS-induced molecular abnormalities. Cigarette smoking increases oxidative stress particularly via activation of NADPH oxidase (NOX), a key source of superoxide anion production. Here we report the inhibitory effects of bioactive phytochemicals, grape seed proanthocyanidins (GSPs), on the migration potential of human non-small cell lung cancer (NSCLC) cells (A549, H460 and H1299) and assessed whether CS-induced NOX activation is their target. Using an in vitro invasion assay, we found that treatment of NSCLC cells with CS condensate (CSC) increased the migration of NSCLC cells in a dose-dependent manner, via enhancing NOX mediated-reactive oxygen species (ROS) accumulation. Treatment of NSCLC cells with GSPs inhibited the cell migration via reduction in ROS accumulation or oxidative stress and subsequent reduction of epithelial-to-mesenchymal transition. To examine the molecular targets of GSPs, we studied the effect of GSPs on CSC-induced alterations in the levels of key NOX components, namely, p22 phox and p47 phox , using A549 cells. We also determined the effect of GSPs on CSC-induced interaction between p22 phox and p47 phox proteins, a key event in NOX activation. Our results indicate that treatment of A549 cells with GSPs not only reverse CSC-induced expression levels of p22 phox and p47 phox , but also inhibit CSC-induced NOX activation by decreasing the binding of p22 phox and p47 phox proteins. This new insight into the anti-lung cancer cell migration activity of GSPs could serve as a basis for chemoprevention or therapy of advanced stage of lung cancer in human patients. Citation Format: Mudit Vaid, Santosh K. Katiyar. Bioactive proanthocyanidins from grape seeds inhibit cigarette smoke condensate-enhanced invasion of human non-small cell lung cancer cells by targeting NADPH oxidase and epithelial-mesenchymal transition. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1240. doi:10.1158/1538-7445.AM2014-1240
Differences in protein staining by Coomassie Brilliant Blue and neutron activated Coomassie Brilliant Blue dyes

The degree of interaction between protein and stains depends in large part upon the protein's content of basic amino acids. We have compared “staining” characteristics of Coomassie Brilliant Blue R-250 with a dye that was rendered radioactive by neutron bombardment. The protein-dye intensities were compared to amino acid composition as in our previous study (Electrophoresis 1986, 7, 327–332). While the data for “colored” dye reflected involvement of basic amino acid residues, quite unexpectedly, the radioactive dye appeared to act in part with the acidic amino acids. This may be due to enhanced binding of dye impurities or radiolysis products.
Infrared and Raman spectra, conformational stability, vibrational assignment, and ab initio calculations of 2-bromo-3-chloropropene

Abstract The infrared (3400-70 cm −1 ) and Raman (3300-20 cm −1 ) spectra of 2-bromo-3-chloropropene, H 2 CC(Br)CH 2 Cl, have been recorded for the gas and solid. Additionally, the Raman spectrum of the liquid has been recorded. Variable temperature (−60–−100°C) studies of the infrared spectrum (3400-400 cm −1 ) of 2-bromo-3-chloropropene dissolved in liquid xenon have been performed. Utilizing two sets of conformer doublets, the enthalpy difference has been determined to be 197 ± 20 cm −1 (563 ± 57 cal mol −1 ), with the anti conformer the more stable form (Cl atom cis to the double bond). Both anti and gauche conformers have been identified in the liquid phase, with the gauche conformer remaining in the annealed solid. The fundamental asymmetric torsional mode for the anti conformer is observed at 88.9 cm −1 . A complete vibrational assignment is proposed based on group frequencies and relative infrared and Raman intensities. The conformational energy difference and optimized geometries of both conformers have also been obtained from ab initio calculations with the RHF/LANL-1DZ, MP2/LANL-1DZ and RHF/4-31G∗/MIDI-4∗ basis sets. Normal coordinate analyses have also been performed with force fields determined from the RHF/4-31G∗/MIDI-4∗ basis set. The calculated frequencies support the proposed vibrational assignment. These data are compared to corresponding data for some similar molecules.
Internet-based home monitoring and education of children with asthma is comparable to ideal office-based care: results of a 1-year asthma in-home monitoring trial.

OBJECTIVE: The goal was to determine whether home asthma telemonitoring with store-and-forward technology improved outcomes, compared with in-person, office-based visits. METHODS: A total of 120 patients, 6 to 17 years of age, with persistent asthma were assigned randomly to the office-based or virtual group. The 2 groups followed the same ambulatory clinical pathway for 12 months. Office-based group patients received traditional in-person education and case management. Virtual group patients received computers, Internet connections, and in-home, Internet-based case management and received education through the study Web site. Disease control outcome measures included quality of life, utilization of services, and symptom control. RESULTS: A total of 120 volunteers (45 female) were enrolled. The groups were clinically comparable (office-based: 22 female/38 male; mean age: 9.0 +/- 3.0 years; virtual: 23 female/37 male; mean age: 10.2 +/- 3.1 years). Virtual patients had higher metered-dose inhaler with valved holding chamber technique scores than did the office-based group at 52 weeks (94% vs 89%), had greater adherence to daily asthma symptom diary submission (35.4% vs 20.8%), had less participant time (636 vs 713 patient-months), and were older. Caregivers in both groups perceived an increase in quality of life and an increase in asthma knowledge scores from baseline. There were no other differences in therapeutic or disease control outcome measures. CONCLUSIONS: Virtual group patients achieved excellent asthma therapeutic and disease control outcomes. Compared with those who received standardized office-based care, they were more adherent to diary submission and had better inhaler scores at 52 weeks. Store-and-forward telemedicine technology and case management provide additional tools to assist in the management of children with persistent asthma.
Critical exponents for alternation in Heisenberg antiferromagnetic chains

Abstract The ground-state energy per site, λ(δ), and singlet-triplet gap, ΔE(δ), of regular ( δ =0) and alternating (δ ≤ 0.01) Heisenberg antiferromagnetic chains are obtained by extrapolating exact numerical solutions of even and odd rings and chains of N ≤ 20 spins. The critical exponents of 1.72 ± 0.02 for λ(δ) and 0.9 ± 0.1 for ΔE(δ) are compared with recent theoretical results for spin-Peierls transitions. Interactions among spinless fermions alter the instability to alternation.
A fracture mechanics based seismic analysis of concrete gravity dams using discrete cracks

Abstract New models for the efficient simulation of discrete crack closure, and fracture mechanics based model for crack propagation, both under transient dynamic conditions, are developed. Following simple validation problems, those two models are integrated into an interactive graphics program which was used to analyse Koyna dam.
The treatment of resonance interference effects in the subgroup method

Abstract This paper describes the development of a method to treat resonance interference effects within the framework of the subgroup method. The new procedure provides for the treatment of multiple resonance absorbers in which the subgroup weights are determined using a least squares technique and based on the cross sections generated from a mixture of multiple resonance isotopes and a suitably wide range of background cross sections. The method was implemented in the Method of Characteristics code DeCART and validated using MCNP. In order to implement the new method, the NJOY code was used for the calculation of neutron spectra and resonance parameters in for each representative LWR mixture. The resonance parameters, lambda, of the scattering isotopes are computed not just with U-238 as the resonance isotope as in previous applications of the subgroup method, but also with U-235 as resonance isotope for the energy groups in which U-238 has no significant resonances. After developing a procedure for generating lambda factors for scattering isotopes, a method is then described for generating subgroup parameters in a homogeneous system. Again NJOY is used for resonance calculations of a set of mixtures for each resonance isotope at each selected temperature. The group average cross sections instead of the resonance integrals of these mixtures are used to generate subgroup parameters using an optimization algorithm. The generated library is then verified by comparing the solution from DeCART with the solution from MCNP. The method is then extended to a heterogeneous system. The code RMET21 is used for transport calculations for the heterogeneous system. The interference effect from the most important resonance isotopes is treated by generating subgroup weights with resonance cross sections for the cases with two resonance isotopes. The results indicate that the subgroup method can accurately represent resonance interference effects within the framework of the subgroup method.
Cost effectiveness model comparing trimethoprim sulfamethoxazole and ciprofloxacin for the treatment of chronic bacterial prostatitis.

Abstract Objectives: Antibiotics are the mainstay for the treatment of men with bacterial prostatitis. Despite numerous treatment strategies involving various types, dosages and duration of antibiotics, no uniform standard has been widely adapted. Moreover, the economic burden of these therapies has been heretofore poorly described. The purpose of this study was to compare the cost effectiveness of various antibiotic treatment regimens for chronic bacterial prostatitis. Methods: After reviewing the literature, we constructed a model that compared 90 days of double strength trimethoprim–sulfamethoxazole and 14, 28 and 60 days of ciprofloxacin 500mg. Parameters examined included initial cure rates, relapse rates, total cure rates, pharmaceutical costs, and total cost of treatment. Using a spreadsheet Markov model, we applied cure rates and relapse rates to a hypothetical cohort of 100 men with culture positive chronic bacterial prostatitis. We then calculated cost of medications and total healthcare costs for the various drug regimens. Results: Twice daily ciprofloxacin @ 500mg for 28 days proved to be the most cost effective treatment for chronic bacterial prostatitis. Yet, after sensitivity analysis, only twice daily ciprofloxacin @ 500mg for 60 days demonstrated consistent benefit over trimethoprim–sulfamethoxazole but at a substantially increased cost. Conclusions: Our model implies that ciprofloxacin 500mg twice daily for 28 days appears to be the most cost effective treatment for chronic bacterial prostatitis. Given the limitations of this type of modeling, long term, prospective, comparative trials will provide the most definitive method of evaluating optimal therapy for chronic bacterial prostatitis.
1991 I.I. Rabi Award. Estimating oxygen saturation of blood in vivo with MR imaging at 1.5 T.

The use of magnetic resonance (MR) imaging is investigated for noninvasively estimating the oxygen saturation of human blood (%HbO2) in vivo by means of relaxation characteristics identified in earlier MR spectrometry studies. To this end, a sequence is presented for determining the T2 of vascular blood in regions in which motions of the body and of the blood itself present a major challenge. With use of this sequence on a commercial 1.5-T whole-body imager, the relationship between the T2 and %HbO2 of blood is calibrated in vitro for the conditions expected in vivo. T2 varies predictably from about 30 to 250 msec as %HbO2 varies from 30% to 96%. T2 values measured in situ for vascular blood in the mediastinum of several healthy subjects qualitatively reflected the behavior observed in vitro. Estimates of %HbO2 for these vessels obtained with the in vitro calibration appear reasonable, particularly for venous blood, although difficulties arise in selecting the appropriate calibration factors. These encouraging initial results support a more systematic study of potential sources of error and an examination of the accuracy of in vivo measurements by comparison with direct measurements of %HbO2 in vessels.
Does necrosis on frozen-section analysis of a mass after chemotherapy justify a limited retroperitoneal resection in patients with advanced testis cancer?

Objective To evaluate morbidity and relapse in patients with advanced testis cancer who underwent a post-chemotherapy resection of a residual mass and a limited retroperitoneal lymph node dissection. Patients and methods A total of 62 patients underwent complete resection of retroperitoneal masses after chemotherapy and a limited lymph node dissection if frozen sections of the mass showed necrosis (37 patients) or a bilateral dissection if the frozen section indicated viable germ cell tumour or teratoma (25 patients). Results With a median follow-up of 6 years, 14 (23%) patients relapsed, but only one within the retroperitoneum (teratoma) after a limited lymphadenectomy. There was a concordance of 89% between the frozen section of the post-chemotherapy mass and the permanent-section histological diagnosis of the entire lymphadenectomy specimen. Of the 37 patients whose masses showed necrosis on frozen section, three had viable germ cell tumour and one had teratoma on final histology. In all four false-negative cases, residual tumour was confined to the resected mass. Six patients (10%) had surgical complications (one after limited and five after bilateral lymph node dissection). Conclusion The surgical resection of all residual masses after chemotherapy, followed by limited retroperitoneal lymphadenectomy if frozen-section analysis shows necrosis, is a safe approach in selected patients with advanced testicular cancer.
Expansion of β-cell mass in response to pregnancy

Inadequate β-cell mass can lead to insulin insufficiency and diabetes. During times of prolonged metabolic demand for insulin, the endocrine pancreas can respond by increasing β-cell mass, both by increasing cell size and by changing the balance between β-cell proliferation and apoptosis. In this paper, we review recent advances in our understanding of the mechanisms that control the adaptive expansion of β-cell mass, focusing on the islet's response to pregnancy, a physiological state of insulin resistance. Functional characterization of factors controlling both β-cell proliferation and survival might not only lead to the development of successful therapeutic strategies to enhance the response of the β-cell to increased metabolic loads, but also improve islet transplantation regimens.
Basal lamina and extracellular matrix alterations in the caudal neural tube of the delayed Splotch embryo

Regional patterns of deposition of laminin (LN), fibronectin (FN), type IV collagen (IV), and heparan sulfate proteoglycan (HSPG) were examined during the formation of the caudal neural tube in embryos homozygous for the delayed Splotch gene and in their normal littermates. Delayed Splotch embryos had neural tube closure defects which extended from the posterior neuropore into the region formed by secondary neurulation. During posterior neuropore closure these components were normally restricted to forming basal laminae, with FN and HSPG additionally deposited in the mesenchyme. Unlike control embryos in which medial regions of the neuroepithelial basal lamina contained greatest amounts of all four, the dorsolateral zone contained less LN and IV and more FN and HSPG, in affected embryos these components were less densely deposited medially, reflecting perhaps the poor structural organization of the notochord. The neuroepithelial basal lamina was often disorganized and wavy compared to the linear pattern typical of controls. By the 12th day, the posterior neuropore of controls had closed and secondary neurulation was underway; however in delayed Splotch embryos, the neural folds remained widely splayed and epithelium newly formed via secondary neurulation extended that abnormally open configuration to the tip of the tailbud. In controls, with mesenchymal cell aggregation FN and HSPG were displaced from between cells to the forming basal lamina. As a central lumen formed within the aggregate LN and IV were added to the basal lamina, and the newly formed epithelium merged with the anterior neural tube. In delayed Splotch embryos, FN and HSPG were incompletely removed from aggregating cell surfaces, the normal morphogenetic cell shaping changes failed to occur and in many embryos a central lumen did not form; the overgrown, aggregated cells merging with the abnormally splayed anterior neural folds. In addition, the critical enrichment of FN and HSPG present between newly formed and consolidated neuroepithelium was displaced in delayed Splotch embryos.
Divalent and mixed divalent/monovalent conduction in β″-alumina: A Monte Carlo study

Abstract A Monte Carlo method is developed for simulation of mixed ionic conductivity in β″-alumina-type materials. The conduction plane of these materials is represented by a lattice gas model in which monovalent and divalent cation carriers diffuse via a vacancy mechanism and interact through a nearest-neighbor coulombic repulsion. By comparing experimental data for pure Na+ and pure Ba2+ β″-aluminas with simulation results, it is possible to estimate the near-neighbor interaction energies ei and jump barriers Ui for both kinds of ions. On the basis of these estimations the total ionic conductivity of Na+Ba2+ β″-alumina is calculated as a function of temperature and concentration of carriers. As Ba2+ replaces Na+, the conductivity initially increases as more vacancies become available. For very high temperatures, this increase continues until exchange is complete; but at lower temperatures, the conductivity reaches a peak for some optimal Ba2+ Na+ composition, and then drops off as the number of Ba2+, and hence the strength of ionic correlation, goes up. The presence of ordering in the fully exchanged (all Ba2+) case manifests itself in substantial curvature of the Arrhenius plots for conductivity. The activation energy for conductivity as a function of Ba2+ mole fraction (XBa2+) shows a pronounced rise near an X value of 2 3 , in agreement with recent experimental observations.
Surface chemistry of dihydromyrcenol (2,6-dimethyl-7-octen-2-ol) with ozone on silanized glass, glass, and vinyl flooring tiles

Abstract The surface-phase reaction products of dihydromyrcenol (2,6-dimethyl-7-octen-2-ol) with ozone (O3), air, or nitrogen (N2) on silanized glass, glass and vinyl flooring tile were investigated using the recently published FACS (FLEC (Field and Laboratory Emission Cell) Automation and Control System). The FACS was used to deliver ozone (100 ppb), air, or N2 to the surface at a specified flow rate (300 mL min−1) and relative humidity (50%) after application of a 2.0% dihydromyrcenol solution in methanol. Oxidation products were detected using the derivatization agents: O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) and N,O-bis(trimethysilyl)trifluoroacetamide (BSTFA). The positively identified reaction products were glycolaldehyde, 2,6-dimethyl-5-heptenal, and glyoxal. The proposed oxidation products based on previously published VOC/O3 reaction mechanisms were: 2,6-dimethyl-4-heptenal, 6-methyl-7-octen-2-one and the surface-specific reaction products: 6-methyl-6-hepten-2-one, 6-methyl-5-hepten-2-one, and 6-hydroxy-6-methylheptan-2-one. Though similar products were observed in gas-phase dihydromyrcenol/O3 reactions, the ratio, based on peak area, of the reaction products was different suggesting stabilization of larger molecular weight species by the surface. Emission profiles of these oxidation products over 72 h are also reported.
Epilogue: agricultural occupational and environmental health policy strategies for the future.

Farmers' health and safety are critical public health problems that have historically been ignored in the United States and in many countries by health policy developers. The challenges to reduce the hazards are significant. However, by mobilizing the resources, the public will, and the structure to carry out preventive programs, progress is possible. Sweden has shown that research, education, engineering, and regulation have resulted in significant reductions of tractor rollover deaths, chainsaw injuries, and hearing loss. Language: en
A compact radiation source for digital subtractive angiography

Abstract Beam requirements for 33 keV radiation used in digital subtraction angiography have been established through extended experimentation first at Stanford and later at the National Synchrotron Light Source in Brookhaven. So far research and development of this medical procedure to image coronary blood vessels have been undertaken on large high energy electron storage rings. With progress in this diagnostic procedure, it is interesting to look for an optimum concept for providing a 33 keV radiation source which would fit into the environment of a hospital. A variety of competing effects and technologies to produce 33 keV radiation are available, but none of these processes provides the combination of sufficient photon flux and monochromaticity except for synchrotron radiation from an electron storage ring. The conceptual design of a compact storage ring optimized to fit into a hospital environment and producing sufficient 33 keV radiation for digital subtraction radiography will be discussed.
The responsibility of the pediatrician in amblyopia

Summary Amblyopia is a common cause of preventable blindness in the United States. It is usually associated with strabismus and is preventable by early and proper prophylactic measures. Pleoptic methods, as succinctly related, are a well-recognized contribution to the treatment of amblyopia and especially amblyopia with eccentric fixation. At large pleoptic centers like the New York Eye and Ear Infirmary, over 5,000 pleoptic treatments are given in a single year.6, 7 But despite the emergence of active methods to treat amblyopia, the major hope still lies in early discovery and prophylaxis by an alert medical team. The responsibility of the pediatrician is to recognize the preamblyope, and by his awareness of the problem, to give the potentially amblyopic child the full benefit of modern prophylactic and pleoptic therapy.
The impact of positive property tax differentials on the timing of development

Abstract To date, few empirical studies have focused on the location decision by residential developers in response to changes in the property tax. Based on a dynamic time-to-development model by Turnbull, this paper finds, using 17 years of parcel level data from Saint Louis County, Missouri, that higher than average tax rates increase the time-to-development for vacant parcels by between 4 and 11%, all else equal. Additionally this paper finds that the tax differential effect is cumulative, resulting in about a 20% increase in the time-to-development for the parcel facing the average number of years with a higher than average rate. These results support the analytical results by both Turnbull [Turnbull, G.K., 1988. The effects of local taxes and public services on residential development patterns. Journal of Regional Science, 28 (4), 541–562.] and McMillen [McMillen, D.P., 1990. The timing and duration of development tax rate increases. Journal of Urban Economics, 28, 1–18.] that the property tax can distort residential capital markets leading to inefficient urban growth, or sprawl.
The use of flow cytometry as a tool for monitoring filament formation of fungi

Flow cytometry (FC) has the ability to discriminate a variety of cell parameters including cell size and complexity, and fluorescence intensity. As yeast cells or fungal spores germinate they undergo a morphological transformation from round oval shaped cells to elongate filamentous forms. To date, monitoring these events has been performed using microscopic examination. Microscopic examination is a labor intensive process that examines a very small percentage of the total cell population. We have developed a method using FC that is rapid, simple to perform, and reproducible. The major advantages of FC include analysis of a larger number of cells, increased objectivity due to nonselective measurements of all cells in the population studied, and the computer related data analysis capability of the flow cytometer.
NMR assignment of polymerase β labeled with 2H, 13C, and 15N in complex with substrate DNA

DNA Polymerase β is a multifunctional enzyme involved in base excision repair of nuclear DNA in vertebrate cells. We present here the first assignments of the full-length protein (335 residues, 39 kDa) in the presence of a double gap—double hairpin DNA (22 nucleotides, 7 kDa).