cssi/SciSciGPT-SciSciNet huggingface dataset:
Cyber-Human-Physical Heterogeneous Traffic Systems for Enhanced Safety

Automated vehicles have immense potentials for improving the safety, efficiency and environmental problems in our existing transportation systems. Despite the tremendous ongoing efforts from both industry and academia, fully autonomous vehicles have not yet been widely deployed in public traffic. In the foreseeable future, automated vehicles will very likely be expected to operate in traffic that involve heterogeneous agents including automated vehicles, human-driven vehicles and pedestrians. Such heterogeneity will bring new challenges to the safety of the traffic system. This paper reviews some existing works related to heterogeneous traffic systems and presents a vision of cyber-human-physical heterogeneous traffic systems that can substantially enhance overall safety.
Ultrafast Nonlinear Plasmon Decay Processes in Silver Nanoclusters

Tunable plasmonic properties of metallic nanostructures play a significant role in enhancing various photo-optical phenomena including solar energy conversion, nonlinear optics, photoluminescence a...
Evidence for interstellar magnetic field re-connection in the Galactic center

Recent observations have revealed interstellar features that apparently connect energetic activity in the central region of our Galaxy to its halo. The nature of these features, however, remains largely uncertain. We present a Chandra mapping of the central 2 times 4 deg^2 field of the Galaxy, revealing a complex of X-ray-emitting threads plus plume-like structures emerging from the Galactic center (GC). In particular, we find that a distinct X-ray thread, G0.17-0.41, is embedded well within a nonthermal radio filament, which is locally inflated. This thread with a width of ~1.6'' (FWHM) is ~2.6' or 6 pc long at the distance of the GC and has a spectrum that can be characterized by a power law or an optically-thin thermal plasma with temperature ~8 keV. The X-ray-emitting material is likely confined within a rope of magnetic field with its strength ~1 mG, not unusual in such radio filaments. These morphological and spectral properties of the radio/X-ray association suggest that magnetic field re-connection is the energy source, providing probably the best evidence so far for this process to occur in the interstellar space. Such re-connection events are probably common when flux tubes of antiparallel magnetic fields collide and/or become twisted in and around the diffuse X-ray plumes, representing blowout superbubbles driven by young massive stellar clusters in the GC. The understanding of the process, theoretically predicted in analog to solar flares, can have strong implications for the study of interstellar hot plasma heating, cosmic-ray acceleration and turbulence.
Medical and Non-surgical Conditions That Can Cause or Contribute to Back Pain in a Child or Adolescent

Traditional teaching has been that back pain in children is rare and warrants a thorough work-up for pathologic causes. While this remains true in younger children, adolescents most frequently experience non-specific, or mechanical, back pain. Identifying patterns of presentation by pathologic causes helps determine when further work-up is warranted in teenagers and helps guide the work-up in younger children. Pathologic causes range from infection of the vertebral body, disc, epidural space, or surrounding soft tissues; benign tumors and malignancies of bone, spinal cord, and nerve roots; leukemia; spondylolytic fractures of the pars interarticularis or vertebral body insufficiency fractures; Scheuermann kyphosis; and systemic or extra-skeletal disease, such as spondyloarthropathy, pneumothorax, and pyelonephritis. Radiographic imaging and laboratory analysis assist in identifying specific etiologies and guiding treatment. Mechanical, or non-specific, back pain remains a diagnosis of exclusion. Recognizing important characteristics of the pain helps determine the degree of work-up warranted before prescribing physical therapy and modification of exacerbating factors.
Targeting regional economic development

Part I: Policy Background 1. Introduction and Overview, Stephan J. Goetz, Steven C. Deller, and Thomas R. Harris 2. Historical Description of Economic Development Policy, Steven C. Deller and Stephan J. Goetz 3. Industry Clusters and Industry Targeting, Martin Shields, David Barkley, and Mary Emery 4. Overview of the Theory Behind TRED, Steven C. Deller 5. Porter's Cluster Strategy and Industrial Targeting, Douglas Woodward and Paulo Guimaraes 6. Impact of Agglomerations on the Economy, Todd Gabe Part II: Empirical Modeling Approaches 7. Modeling the Probability of Manufacturing Activity in the Great Plains John C. Leatherman and Terry L. Kastens 8. Regional Variation in the Location Choice of Goods- and Service-Producing Industries Hanas A. Cader, John C. Leatherman, and John M. Crespi 9. An Application of a Double Hurdle Firm Location Model: The Example of Montana, Alison Davis and Thomas R. Harris 10. Targeting Industry Clusters for Regional Economic Development: The REDRL Approach David L. Barkley and Mark S. Henry 11. Rural-Urban Economic Linkages: Implications for Industry Targeting Recommendations, David W. Hughes 12. Regional Cluster Analysis with Interindustry Benchmarks, Edward Feser, Henry Renski, and Jun Koo 13. Targeting with the Analytic Hierarchy Process, Thomas G. Johnson 14. The Community Business Matching Model: Combining Community and Business Goals and Assets to Target Rural Economic Development, Linda J. Cox, Jonathan E. Alevy, Thomas R. Harris, Barbara Andreozzi, Joan Wright, and George "Buddy" Borden Part III: Applications and Case Studies 15. Identifying Food Industry Clusters: A Comparison of Analytical Tools, Stephan J. Goetz, Martin Shields, and Qiuyan Wang16. Targeted Industry Analysis in a "Comprehensive" Economic Development Extension Program, James R. Nelson, Michael D. Woods, La Dee Homm, and Gerald A. Doeksen 17. TRED as an Educational Tool, Steven C. Deller, John Leatherman, and Martin Shields 18. Industry Targeting: Theoretical Underpinning and Practical Application, David W. Hughes 19. Import Substitution and the Analysis of Gaps and Disconnects, Steven C. Deller 20. What Have We Learned?Steven C. Deller, Stephan J. Goetz, and Thomas Harris.
Skin and Soft Tissue Infections in the Geriatric Patient

Geriatric patients are more prone to the development of necrotizing skin and soft tissue infections because of the risk factors associated with aging. Because this diagnosis is not always obvious by physical exam, laboratory testing, and imaging, these patients must be approached with a high index of suspicion in order to appropriately manage these infections. Necrotizing soft tissue infections are classified by microbiologic etiology and proper key providers into correct identification of offending pathogens; however, surgery is the mainstay of therapy. Nonoperative treatment modalities offer helpful adjuncts but cannot replace source control. Ultimately, these infections in the geriatric population can be devastating and are associated with high morbidity and mortality as patients have decreased physical reserve and ability to recover from the septic insult. Prompt diagnosis and management give these patients the best opportunity for survival and recovery.
Post-transplant Cyclophosphamide Versus Thymoglobulin in HLA-Mismatched Unrelated Donor Transplant for Acute Myelogenous Leukemia and Myelodysplastic Syndrome.

ABSTRACT Limited information is available on the efficacy of post-transplantation cyclophosphamide (PTcy) or thymoglobulin for graft-versus-host disease (GVHD) prophylaxis in mismatched unrelated donor (MMUD) transplants. We retrospectively compared outcomes of 76 adult patients with acute myelogenous leukemia (AML) or myelodysplastic syndrome (MDS) who underwent 7/8 HLA-MMUD transplantation and received either PTcy (50 mg/kg on day 3 and 4) or thymoglobulin (total dose 4.5 mg/kg) for GVHD prophylaxis. In addition, tacrolimus and mycophenolate were used in both groups. Propensity score-based multivariable analyses (PSCA) were performed to adjust confounding effects of patient characteristics between both groups. Between January 2006 and June 2019, 25 patients received PTcy, and 51 received thymoglobulin. Median age of the population was 57 years, 78% of patients had AML, most common graft source was peripheral blood (96%), and 46% received myeloablative conditioning regimens. Median time to neutrophil (15 versus 11 days, P
Modeling and analysis of cilia generated shear-rate dependant flow

Abstract The ciliated channel is a universal structure that is involved in organism-tube, and cilia beating makes a significant impact on bio-fluid transport. Inspired by the biological discovery of the cilia applications, in this novel study, we illustrate the characteristics of the mass transfer of non-Newtonian fluid in a ciliated channel. We assume that a metachronal wave of cilia generates a two-dimensional wavy channel. We consider Carreau materials, whose viscosities are dependent on both the infinite-shear-rate and zero-shear-rate. The transformation from fixed coordinates to moving coordinates is employed. We reduce the constitutive equations by hypotheses of small Reynolds number and wave number. The simplified system is solved via a perturbation method with a stream function. Finally, we sketch visualizations of velocity, pressure gradient, and pressure difference versus different parameters of physical interests. We analyze the effects of different boundary layers on fluid flow. Besides, graphical results for pressure rise, velocity field, and streamline are attained. This study is the provision of suggestive results in designing biomaterial nanotechnology.
Utility of machine learning algorithms in degenerative cervical and lumbar spine disease: a systematic review

Machine learning is a rapidly evolving field that offers physicians an innovative and comprehensive mechanism to examine various aspects of patient data. Cervical and lumbar degenerative spine disorders are commonly age-related disease processes that can utilize machine learning to improve patient outcomes with careful patient selection and intervention. The aim of this study is to examine the current applications of machine learning in cervical and lumbar degenerative spine disease. A systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A search of PubMed, Embase, Medline, and Cochrane was conducted through May 31st, 2020, using the following terms: “artificial intelligence” OR “machine learning” AND “neurosurgery” AND “spine.” Studies were included if original research on machine learning was utilized in patient care for degenerative spine disease, including radiographic machine learning applications. Studies focusing on robotic applications in neurosurgery, navigation, or stereotactic radiosurgery were excluded. The literature search identified 296 papers, with 35 articles meeting inclusion criteria. There were nine studies involving cervical degenerative spine disease and 26 studies on lumbar degenerative spine disease. The majority of studies for both cervical and lumbar spines utilized machine learning for the prediction of postoperative outcomes, with 5 (55.6%) and 15 (61.5%) studies, respectively. Machine learning applications focusing on degenerative lumbar spine greatly outnumber the current volume of cervical spine studies. The current research in lumbar spine also demonstrates more advanced clinical applications of radiographic, diagnostic, and predictive machine learning models.
Normalized vertebral-level specific range of motion corridors for female spines in rear impact.

OBJECTIVE It is well known that the biomechanical responses of female and male spines are different in rear impacts. Female-specific finite element models are being developed as improvements over generic models. Such advancements need female-specific segmental responses for validation. The objectives of the study were to develop vertebral level-specific range of motion corridors from female human cadaver head-neck complexes exposed to rear impact loading. METHODS Previously conducted experiments from five human cadaver head-neck complexes were used in this analysis-based study. Briefly, the female head-neck complexes were isolated at the second thoracic vertebral level from the whole body such that the skin and the surrounding tissues of the osteoligamentous complex were intact. The distal end was fixed to the platform of a min-sled testing device. The anterior angulation of T1 was at 25 degrees with respect to the horizontal axis to simulate the normal driver posture. The occipital condyles were directly superior to the T1 body, and the Frankfort plane was horizontal. Rear impact loading were applied at a velocity of 2.6 m/s. The range of motion was defined as the inter-segmental angle at each level of the subaxial spinal column, and it was obtained by tracking the motion of the retroreflective targets that were secured on vertebral bodies and lateral masses of C2 through C7 vertebrae. Data were normalized with respect to the fifth percentile female total body mass, and corridors were developed using the equal stress equal velocity approach and expressed as mean ± 1 standard deviation corridors for each segment. RESULTS The segmental motions of the subaxial cervical spinal column were such that the upper regions responded with flexion while the lower regions responded with extension during the initial accelerative loading phase of the impact, resulting in a non-physiological curvature. During the later phase, all segments were in extension. individual corridors are presented as temporal responses in the body of the manuscript. A comparison of the mean temporal responses at each segment are presented to depict the angulation motion differences within the spinal column. CONCLUSIONS The present corridors are unique to the female spines. Because female spines have significantly (p < 0.05) different biomechanical responses when compared to male spines, local anatomical differences exist between male and female spines, and field data and clinical studies show female bias to whiplash associated disorders under the rear impact of loading, the present set of corridors serve as a fundamental dataset for the validation of female-specific finite element models. Current computational models can also use these corridors for improved validation to add confidence in their outputs.
Practical Procedures for Technical and Economic Investigation of Ship Structural Details

Local structural problems in ships are generally the result of stress concentrations in structural details. The intent of this paper is to bring to the attention of the marine industry that costly repairs and lay-up time of a vessel can often be prevented, if these problem areas are recognized and investigated in the design stages. Such investigations can be performed for minimal labor and computer costs using finite element analysis techniques. Practical procedures for analyzing structural details are presented in the paper including discussions of the results, and the analysis costs expended. It is shown that the application of the finite element analysis technique can be economically employed in the investigation of structural details.
Mobilizing Poor Voters : Machine Politics, Clientelism, and Social Networks in Argentina

Democracy has provided opportunities for political representation and accountability, but it has also created incentives for creating and maintaining clientelistic networks. Why has clientelism consolidated with the introduction of democracy? Drawing on network analysis, Mobilizing Poor Voters answers this question by describing and explaining the emergence, maintenance, and disappearance of political, partisan, and social networks in Argentina. Combining qualitative and quantitative data gathered during twenty-four months of field research in eight municipalities in Argentina, Mobilizing Poor Voters shows that when party leaders distribute political promotions to party candidates based only on the number of voters they mobilize, party leaders incentivize the use of clientelistic strategies among candidates competing to mobilize voters in poor neighborhoods. The logic of perverse incentives examined in this book explains why candidates who use clientelism succeed in getting elected and re-elected over time, contributing to the consolidation of political machines at the local level.
Spiral-based 3D MR thermometry

Real time MR thermometry, usually based on the proton-resonance frequency shift, is a key aspect of MR-guided focused ultrasound procedures. The desire to monitor the entire sonicated volume has led the field towards the development of rapid, 3D methods; however, acquiring fully sampled 3D volumetric data to monitor heating is time consuming, and so fast methods must be developed in order to meet the spatial and temporal requirements for adequate monitoring of thermal therapy. The data acquisition efficiency of spiral trajectories is higher than that of Cartesian scanning. Therefore, spiral trajectories are an attractive way to improve temporal resolution while maintaining spatial resolution in MR thermometry. We have recently reported that a variation on the traditional spiral-out trajectory, called the redundant spiral-in/out trajectory, has certain advantages in terms of off-resonance performance. We hypothesize this trajectory to also be advantageous for PRF thermometry. Here, we have implemented this –in/out trajectory, compared its performance in terms of the focal spot size and position shift versus a Cartesian and spiral-out acquisition, and have generated rapid 3D temperature maps using the method.
Compared performances of trellis coded QDPSK modulation and CPFSK modulation with discrimination detection

The performance of a trellis coded four phase differential phase shift keying (TC QDPSK) modem with symbol decoding is compared with a continuous phase frequency shift keying (CPFSK) modem using noncoherent detection. The bit error rate (BER) performance as a function of signal-to-noise ratio per bit is obtained by simulation of both systems. It is shown that the trellis coded system provides a better BER performance for a given signal-to-noise ratio per bit. The bandwidth requirements for both systems are analyzed and compared. The TC 4DPSK system trades off part of the maximum achievable coding gain for a simpler implementation. >
A soft error monitor using switching current detection

Technology scaling has led to a reduction in the stored charge in SRAM memories. This has increased their vulnerability to soft errors. Conventional approaches to detect/correct soft errors, such as ECC, have limitation in the number of soft errors that can be tolerated. In this paper, we propose a soft error detection circuit which utilizes a current mirror to translate switching current pulses induced by soft errors into voltage pulses. This pulse is then sensed by a Schmitt trigger to generate an error signal. Our experimental results show that the proposed scheme is tolerant to process variation and results in low power overhead without significantly affecting performance.
Pharmacokinetics and Pharmacodynamics of Labetalol in Elderly and Young Hypertensive Patients Following Single and Multiple Doses

Several physiologic changes accompany the aging process and may alter the pharmacokinetics and pharmacodynamics of drugs given to elderly patients. The primary purpose of the present investigation was to compare the pharmacokinetics of labetalol in young and elderly hypertensive patients. Limited data regarding the pharmacodynamics of labetalol in each of these age groups were also evaluated. Ten young (age 32-48 yrs) and nine elderly (age 60-68 yrs) patients with essential hypertension were evaluated after the first and last doses of a 15-day regimen of labetalol. The young group received 200 mg orally at 9:00 P.M. and 9:00 A.M.; the elderly group received 200 mg once daily at 9:00 P.M. No significant differences in the mean (SD) apparent oral clearance of the drug existed between groups after the first [4.8 (1.9) and 4.3 (1.2) L/hr/kg] and final [4.4 (2.2) and 3.4 (1.0) L/hr/kg] doses of labetalol. No changes in any pharmacokinetic values for labetalol were detected as a function of age. Changes in standing blood pressure and heart rate after the first and last doses were generally similar between the young and elderly hypertensives. Labetalol was effective and well tolerated in both groups.
IFNγ attenuates of yellow fever virus 17D vaccine strain in vivo and its implication for severe adverse events (VIR1P.966)

The yellow fever virus (YFV) vaccine strain 17D elicits long-lasting immunity against wild-type YFV infection. The success of 17D has led to vaccine candidates using 17D as a vector to deliver heterologous antigen against other pathogens. However, the attenuation mechanism for 17D remains elusive and reports of rare but potentially lethal severe adverse events (SAE) post-vaccination raise questions about the continued use of 17D. Type I IFN receptor-deficient mice (AB6) are susceptible to subcutaneous infection with WT virus and display clinical signs of disease similar to humans whereas 17D infection is self-limiting. In mice lacking both type I and type II IFN receptors (AGB6), 17D results in a lethal infection, suggesting that the vaccine virus is attenuated by IFNγ. Intact IFNγ responses restrict 17D replication to lymphoid organs whereas 17D spreads viscerally and neuroinvades leading to paralysis in the absence of IFNγ. Interestingly, IFNγ production is largely restricted to draining lymph nodes (DLN) but antiviral gene induction is observed globally. In the presence of IFNγ, we observe more robust expression of MIG, MCP-1 and IFIT1, indicative of potential downstream effectors against 17D. We are investigating the DLN immune infiltrates and identifying the IFNγ producing cells. Our data suggest that host-specific variations in the IFNγ signaling network may increase susceptibility to SAE following vaccination.
Anthranilate Synthetase from Serratia marcescens ON THE MECHANISM OF TRYPTOPHAN INHIBITION

Abstract Reactivity of sulfhydryl groups with 5 ,5'-dithiobis(2-nitrobenzoate) in 4 m urea and fluorescence emission of 1-anilinonaphthalene-8-sulfonate were used to probe changes in enzyme conformation. The substrate chorismate and the end product inhibitor tryptophan caused conformational alterations in anthranilate synthetase which were related to the mechanism of catalysis and inhibition, respectively. Tryptophan increased the rate of reaction of enzyme sulfhydryl groups while chorismate decreased the rate. Tryptophan and chorismate both decreased the fluorescence emission of enzyme-bound 1-anilinonaphthalene-8-sulfonate, but to different extents. The concentration dependence for changes in conformation correlated with saturation of catalytic and inhibitory sites with chorismate and tryptophan, respectively. Binding of chorismate and tryptophan was measured by equilibrium dialysis. Sites for 1 to 2 eq of each ligand were detected. Mg2+ reduced the dissociation constant for chorismate binding by 3- to 4-fold but did not change the number of available sites. Binding of tryptophan antagonized binding of chorismate and vice versa. Binding of tryptophan and chorismate appeared to be mutually exclusive although the data were not sufficiently precise to prove this point unequivocally. It is proposed that inhibition of anthranilate synthetase activity results when tryptophan binds to a regulatory site and maintains the enzyme in a conformation having poor affinity for substrates. The chorismate-dependent conformational change which was detected may facilitate binding of the second substrate glutamine.
An Adaptive Algorithm for the Optimal Sample Size in the Non-Stationary Data-Driven Newsvendor Problem

We investigate the impact of the sample size in the non-stationary newsvendor problem when the underlying demand distribution is not known, and performance is measured by the decision-maker’s average regret. The approach we propose is entirely data-driven, in the sense that we do not estimate the probability distribution of the demand and instead rely exclusively on historical data. We propose an iterative algorithm to determine the number of past observations that should be included in the decision-making process, provide insights into the optimal sample size and perform extensive computational experiments.
CFD-based modeling and design for energy-efficient VOC emission reduction in surface coating systems

Volatile organic compounds (VOC’s) are among the most hazardous substances generated in surface coating operations. Hence, VOC emission must be strictly controlled. In this paper, we introduce a CFD-based system modeling and analysis approach to investigate VOC emission mechanisms and to identify the key design and operation parameters of a general surface coating application system for energy-efficient emission reduction. A case study on paint spray in different design environments demonstrates the efficacy of the introduced modeling and analysis approach. It shows that a redesign of the ventilation system of a spray booth and an adjustment of the operational parameter can reduce VOC emission to the level below the threshold limit value; meanwhile, the energy efficiency can be improved significantly. The introduced modeling and analysis technique for energy-efficient VOC reduction is applicable to various industrial practices.
Lower urinary tract pharmacology III. Neuropharmacologic basis for lower urinary tract dynamics

In vivo studies. Electrical stimulation of the sympathetic and parasympathetic systems is often combined with intravenous administration of autonomic drugs. The effects of receptor stimulation or blockade are recorded as changes in intravesical pressure and flow,lm3 as changes in intraurethral pressure,4 or as variation in the tension of the bladder musculature.5 In situ evaluation with discontinuity of bladder and urethra. In Jonas and Tanagho’s model,6 the bladder and urethra are left in situ but are surgically separated. The blood supply remains intact. This arrangement makes it possible to record separately, simultaneous intravesical and intraurethral pressures while eliminating the factor of direct continuity. In vitro perfusion of bladder outlet region (bladder base, bladder neck, and proximal urethra). 7*10 The specimen is perfused in an organ bath, and the effect of various autonomic drugs are studied as a function of variation in the resistance to flow through the bladder outlet. This technique preserves the anatomic configuration of the outlet region. In vitro studies on isolated strips of bladder and urethra. Muscle segments from the lower urinary tract are studied in a tissue bath.‘l,” The use of isolated muscle segments avoids modification of the response to pharmacologic agents by spinal reflexes and humoral factors. This technique fulfills the requirements for pharmacologic evaluation of receptors as specified by Furchgott. l3 However, extrapolation of results to the intact organ may be difficult. Electron microscopic and histochemical techniques. Delineating the distribution of cholinergic and adrenergic nerves in the bladder and bladder outlet provides a basis for understanding the nature of these fibers and the site and mode of action of drugs acting on them. 14-20 Disagreements concerning the role of sympathetic and parasympathetic nervous system in the regulation of bladder outlet function are largely due to two factors: (1) the response of an in vitro experimental laboratory model does not always reflect the in vivo response, and (2) responses vary with different species of investigational animals. For instance, sympathetic nerve stimulation and epinephrine will bring about contractions of the outlet region in the cat21-23 and man,24 while divergent responses are obtained in the dog and rabbit to the same type of activation.22 This may be caused by species variations in localization and function of adrenergic receptors. 25
Visible Light Emission from Erbium Doped Yttria Stabilized Zirconia

ABSTRACT: One of the major shortcomings of silicon (Si) as a semiconductor material is its inability to yield efficient light emission. There has been a continued interest in adding rare earth ion impurities such as erbium (Er) to the Si lattice to act as light emitting centers. The low band gap of Si however has complicated this practice by quenching and absorbing this possible emission. Increasing the band gap of the host has been successfully tried in the case of gallium nitride (GaN) [1] and Si-rich oxide (SRO) [2] alloys. A similar approach has been tried here, where Er oxide (ErO x ) nanocrystals have been formed in a yttria stabilized zirconia (YSZ) host deposited on a Si (100) substrate. The YSZ is deposited as a heteroepitaxial, insulating layer on the Si substrate by a reactive sputtering technique. The Er is also incorporated by a sputtering process from a metallic target and its placement in the YSZ host can be easily controlled. The device structure formed is a simple metal contact/insulator/phosphor sandwich. The device has been found to emit visible green light at low bias voltages. The advantage of this material is that it is much more structured than SiO 2 which can theoretically lead to higher emission intensity.
Medical ethics curriculum for surgical residents: results of a pilot project

Abstract Introduction: This study sought to develop and evaluate a medical ethics curriculum designed specifically for surgical residents. Methods: The learning needs of surgical residents relevant to ethics were determined by using a structured literature review and synthesis strategy. We identified 5 primary areas of importance for ethics education for surgical residents: withdrawing and withholding treatment, advance directives, do-not-resuscitate orders, informed consent, and communicating bad news. Learning objectives were developed, and teaching plans were designed for four 90-minute interactive teaching episodes on the basis of adult learning principles. We surveyed residents using a published survey instrument modified for surgery to identify residents' beliefs about the usefulness of ethics training, confidence in addressing ethical issues, and factual knowledge of ethics questions. Results: Twenty surgical residents at a single institution completed the pretest and posttest close-ended surveys. Results showed that although 88% had formal ethics exposure in medical school, 93% considered ethics education at the resident level to be a “very important” or “important” topic. Residents' confidence in addressing ethical issues showed statistically significant improvement between pretest and posttest surveys for 13 of 23 items. There were no statistically significant linear relationships between postgraduate year of residency and the pretest confidence items or the number of correct responses on the pretest multiple-choice items. Conclusions: Despite the prevalence of ethics education during medical school, surgical residents welcome formal instruction on numerous ethical issues pertinent to surgical practice. A focused curriculum can be developed that has a measurable impact on residents' confidence in addressing ethical issues. (Surgery 1999;126:701-7.)
Metallic glasses as novel catalysts

Metallic glasses are nonequilibrium amorphous metal alloys which combine the metallic electronic structure with a disorered atomic structure usually reserved for ceramic and polymeric materials. Amorphous silicon-based structures have already been shown to be effective in semiconductor1,2 and photovoltaic applications3, where single crystal structures were previously thought to be required. The properties of metallic glasses have been reviewed recently by Gilman4 and Turnbull5. Recent reports demonstrate that metallic glasses are indeed both catalytically active6 and uniquely selective7. Here we disclose the nature of this unique selectivity. We report observations of glassy Pd–Si and Pd–Ge alloys which exhibit different selectivity in catalysis of hydrogen reactions than their crystalline Pd systems. We also observe an increase in the activity of these amorphous catalysts when partial crystallization occurs.
Preparation of iron oxide-based calcium sensors for MRI.

We describe a protocol for the preparation of a family of calcium indicators for MRI. The indicators consist of superparamagnetic iron oxide nanoparticles functionalized with the calcium-sensing protein, calmodulin, and its target peptides. Calcium-dependent protein–protein interactions drive particle clustering and produce large changes in T2 relaxivity. To prepare these indicators, interacting polypeptides are purified, biotinylated and then conjugated to streptavidin-coated nanoparticles. Conjugates are isolated, mixed to obtain functional sensors and incubated in the presence or absence of calcium to test response properties. Calcium-dependent responses are assayed by dynamic light scattering and MRI. The whole series of procedures can be carried out in ∼12 h. The iron oxide-based calcium sensors discussed here are suitable for the detection of calcium concentration changes of ∼1 μM in vitro.
A comparison of pore structural properties of carbons with combustion synthesized titanium carbides

Abstract A systematic study was undertaken to investigate the pore structural properties of combustion synthesized titanium carbides by varying the surface areas of graphitic and activated carbons. Adsorption-desorption isotherms were constructed following the principles of gas adsorption by using nitrogen as an adsorbent at liquid nitrogen temperature. Pore structural properties such as surface area, total pore volume, cumulative pore volume and pore size distributions were calculated for both the carbons and combustion synthesized titanium carbides. The results indicate a collapse of the original porosity of carbon after a carbide has been synthesized, immaterial of the type of carbon and its surface area. Microstructures of non-stoichiometric carbides exhibited melting and spreading of titanium. Collapse of the original porosity of carbon has been attributed to the capillary diffusion of liquid titanium aided by its high diffusivity and low viscosity forming a titanium carbide at the combustion temperatures involved.
Processing of Bacillus subtilis small cytoplasmic RNA: evidence for an additional endonuclease cleavage site

Small cytoplasmic RNA (scRNA) of Bacillus subtilis is the RNA component of the signal recognition particle. scRNA is transcribed as a 354-nt precursor, which is processed to the mature 271-nt scRNA. Previous work demonstrated the involvement of the RNase III-like endoribonuclease, Bs-RNase III, in scRNA processing. Bs-RNase III was found to cleave precursor scRNA at two sites (the 5' and 3' cleavage sites) located on opposite sides of the stem of a large stem-loop structure, yielding a 275-nt RNA, which was then trimmed by a 3' exoribonuclease to the mature scRNA. Here we show that Bs-RNase III cleaves primarily at the 5' cleavage site and inefficiently at the 3' site. RNase J1 is responsible for much of the cleavage that releases scRNA from downstream sequences. The subsequent exonucleolytic processing is carried out largely by RNase PH.
Homothallic Sordariaceae from nature: The absence of strains containing only thea mating type sequence

Abstract An efficient procedure is described for the isolation of heterothallic and homothallic Sordariaceae from soil. New strains obtained by this method were classified to genus on the basis of ascospore morphology and ornamentation. Hetero- and homothallic Neurospora spp. were most often isolated from soils collected in the tropics, whereas Gelasinospora spp. were obtained from both tropical and temperate zone soils. The use of molecular probes on genomic DNA of the isolates showed that all of the new homothallic Neurospora strains contained a sequence similar to the A mating type sequence of N. crassa , but none contained a sequence similar to the a mating type. In contrast, all of the homothallic Gelasinospora strains contained sequences similar to both the A and a mating type sequences of N. crassa . Genomic DNA from type cultures of homothallic species of Gelasinospora ( G. calospora, G. reticulospora , and Gelasinospora S23), Sordaria ( S. fimicola and S. macrospora ), and Anixiella ( A. sublineata ) also contained sequences similar to the N. crassa A and a sequences. Unlike the homothallic Gelasinospora , heterothallic Gelasinospora isolates contained a sequence corresponding to either the A mating type or the a mating type, but not both. Hybridization with additional molecular probes was performed to characterize the new isolates further on the basis of restriction fragment length polymorphisms (RFLPs). Surprisingly, many of the homothallic strains could not be distinguished from one another either morphologically or on the basis of several molecular probes, although they were isolated from distinct geographical regions. This is in contrast to numerous RFLPs detected between heterothallic Gelasinospora and Neurospora isolates.
Resource-aware broadcast encryption for selective-sharing in mobile social sensing

The rapid proliferation of smartphones has led to the emergence of mobile social sensing applications, spanning sharing of health data, location-based encounters, and transportation. A major concern for such applications is selective sharing, i.e., how does a user publish a sensor data stream confidentially to only authorized members in his/her social network? The needs of mobile sensing applications, such as dynamic communities and data dissemination from resource-constrained handhelds, make this problem more challenging than apparent. The novelty of this paper lies in the use of a cryptographic scheme called broadcast encryption to enable selective sharing for mobile social sensing. This is in contrast to unicast or pairwise encryption that is commonly used today. We evaluate state-of-art broadcast encryption schemes and note that they provide either efficiency, or adaptation to dynamic group sizes, but not both. We propose ECS (Extended Complete Subtree), a resource-aware broadcast encryption scheme that can efficiently support dynamic groups. We implement each encryption scheme on the Nokia N800 handheld device and demonstrate that ECS is more feasible than other schemes in terms of key storage, code size, and encryption and decryption efficiency.
Advantages of Open Mitral Commissurotomy Using a Triple-Orifice Technique

Our experience over an eight-year period with the operative relief of mitral stenosis is reviewed and detailed. Of the 106 patients in the series, 80% had minimal or no calcification, 17% had moderate calcification, and 4% had severe calcium deposits in the valve. Four patients have required reoperation for recurrent stenosis, with valve replacement in 3 and a second commissurotomy in the fourth. Left atrial thrombus was encountered in 16%, and no patient with thrombus experienced embolization in the postoperative period. One postoperative death occurred within 30 days, and a single late death occured 35 days after operation. For the scarred, retracted mitral valve we have utilized a multiple-orifice technique that provides maximal flow without the risk of inducing significant mitral insufficiency.
Calculation of Stresses in Crosslinking Polymers

A general constitutive model is presented for calculating the evolution of stresses in crosslinking polymers. The analysis is valid for thermo- and chemorheologically simple polymers and for time-dependent strain histories where the total strain at any time is not large, such that linear viscoelasticity applies. We identify the material parameters required and outline experimental and theoretical methods for their determination. This formalism is then used to calculate the development of cure stresses for an epoxy wherein the glass transition temperature exceeds the cure temperature during the reaction. Finally, we discuss practical methods of stress minimization through control of the cure cycle.
Optical Properties of Distyrylbenzene Chromophores and their Segmented Copolymers

Abstract : A new segmented polymer (3) consisting of a distyrylbenzene chromophore separated by polyethylene glycol segments has been prepared by two independent methods: a novel, polymer analogous Mitsunobu reaction and conventional double displacement reaction. The polymer is soluble in a variety of organic solvents, forms excellent, optically clear films and exhibits strong fluorescence. The properties of the chromophore and the polymer, as well as the scope and limitations of the novel Mitsonobu polymerization are presented. Attempts to use polymer (3) in electroluminescent devices are also discussed.
A new multi-locus timescale reveals the evolutionary basis of diversity patterns in triggerfishes and filefishes (Balistidae, Monacanthidae; Tetraodontiformes)

Balistoid fishes (triggerfishes, filefishes, leatherjackets) represent one of the most successful radiations of tetraodontiform fishes across the world’s oceans. Balistids (triggerfishes) are largely circumtropical in coral reef environments while most monacanthids (filefishes, leatherjackets) are distributed across reef and non-reef habitats in the Indo-western Pacific. Although members of these clades share a distinctive mode of locomotion that relies upon coordinated oscillation or undulation of enlarged dorsal and anal fins, species richness as well as morphologial and ecological diversity are generally considered to be higher in monacanthids than in triggerfishes. Explicit evolutionary comparisons of diversity patterns between these sister clades have been hampered by the paucity of systematic studies of filefishes relative to triggerfishes. Furthermore, a well-sampled molecular timescale for balistoids is lacking, hindering our understanding of the evolutionary history of these fishes. Here, we produce the largest balistoid molecular dataset to date, based on two mitochondrial and three nuclear loci, for a total of 86 species, and we time-calibrate it using three tetraodontiform fossils. We show that several of the traditional monacanthid genera are not monophyletic and that the balistid Xenobalistes tumidipectoris is nested within the genus Xanthichthys, and suggest that the generic name Xenobalistes be dissolved. Our timetree reveals a Late Miocene origin of balistids, in accordance with previous studies, but a Late Eocene age for the crown monacanthids, which experienced significant diversification during the Late Oligocene and Early Miocene. Comparative analyses reveal no significant family-level differences in rates of speciation or body size evolution, suggesting that the greater diversity of filefishes can be attributed to their more ancient crown age compared to triggerfishes.
Amplitudes of the two-nucleon interaction at 579 MeV

A complete amplitude analysis is presented of the 579-MeV data set for p-p elastic scattering. Although all continua of ambiguities are eliminated by the extensive nature of the data, discrete ambiguities remain, as expected from general criteria for such ambiguities. In particular, four solutions are found. Further experiments are specified which can resolve this remaining ambiguity also. A comparison is also made with previous amplitude results at this energy.
Karmarkar's algorithm with improved steps

We define a function of the interior of the feasible region of Karmarkar's canonical linear program with the property that its supremum is bounded above by one, if and only if the optimal value of the linear program is zero. We use this function to obtain data-dependent steps for Karmarkar's algorithm. The corresponding reduction in the potential function improves upon the data-independent reduction derived by Padberg. We analyze the general step and consider its potential practical advantages.
Effects of Mutations of Proline Residues Located in the Complementary Subunit of the Acetylcholine Receptor Transmitter Binding Site

Nicotinic acetylcholine receptor-channels (AChRs) are allosteric proteins that isomerize between a non-conducting/low-affinity and a conducting/high-affinity conformation. Each neuromuscular AChR has two transmitter binding sites located at the interface between adjacent subunits (αeor αδ.We studied the gating properties of AChRs with mutations at the vicinal prolines located at these interfaces. In both cases, mutations of the N-terminal residue had little effect but those of the C-terminal residue (eP121 or δP123) decreased substantially the open channel probability (500 μM ACh). We estimated the unliganded (E0) and diliganded (E2) gating equilibrium constants for mutations of these two prolines from single-channel currents (30 mM ACh, +100mV). All of the tested substitutions decreased both gating constants. The slope of the rate-equilibrium plot (Φ)for eP121/δP123 was ∼0.96 (diliganded) and ∼0.70 (unliganded). Some of the mutations caused a large decrease in the closed/open equilibrium dissociation constant ratio for ACh (λACh) while others had more modest effects. Probing the effects of eP121 and δP123 mutations should allow an estimation of the binding and gating properties of each of the two transmitter binding sites, separately.
Landslide-driven distribution of aspen and steppe on Kathul Mountain, Alaska

Abstract The patchy arrangement of woodland and steppe on the south face of Kathul Mountain, Alaska, challenges common distribution theories based on slope, aspect, and elevation, and poses questions about the effects of disturbance and the process of succession in the bluff environment.Populus tremuloides(quaking aspen) andPopulus balsamifera(balsam poplar) on Kathul Mt. show a strong affinity for areas prone to frequent, catastrophic landslide disturbance and associated substrate. A study of substrate and vegetation reinforces surficial evidence and eliminates some possible explanations. Slope, aspect, elevation, and soil type were found to have no discernible effect upon distribution. The failure of existing theory to explain this distribution prompts several hypotheses, based on topographic effects on snowfield accumulation, vegetative influences upon soil moisture, and competitive attributes of the steppe community. Many of these processes have long been recognized in semi-arid grasslands around the world.
Zinc and human development: A review

In the last few years, considerable evidence has been obtained regarding the importance of zinc in human nutrition. Zinc is an important component of many metalloenzymes and is also required for metabolism of nucleic acids and synthesis of protein. Human requirements for zinc vary at different times in development, but appear to be particularly high during embryonic life, during periods of rapid growth, and during pregnancy. Although zinc is widely distributed in foods, a number of types of diets appear to be deficient or marginal in terms of available zinc. In addition, there is physiological loss of zinc in bleeding and sweating which may lead to low levels of body zinc. A syndrome characterized by markedly retarded growth and sexual development that occurs in the Middle East has been shown to be due to zinc deficiency. This syndrome is reviewed. It is thought that the zinc deficiency syndrome is only one end of a continuum of growth-related problems associated with low levels of physiologically available zinc. In rats, zinc deficiency during pregnancy has been shown to lead to congenital malformations in a large percentage of the offspring. A number of these malformations involve the central nervous system. We have suggested that epidemiological data support the possible importance of maternal zinc deficiency as an etiological factor in human CNS malformations. These data are discussed.