cssi/SciSciGPT-SciSciNet huggingface dataset:
Invariant domain preserving discretization-independent schemes and convex limiting for hyperbolic systems

Abstract We introduce an approximation technique for nonlinear hyperbolic systems with sources that is invariant domain preserving. The method is discretization-independent provided elementary symmetry and skew-symmetry properties are satisfied by the scheme. The method is formally first-order accurate in space. Then, we introduce a series of higher-order methods. When these methods violate the invariant domain properties, they are corrected by a limiting technique that we call convex limiting. After limiting, the resulting methods satisfy all the invariant domain properties that are imposed by the user (see Theorem 7.24) and is formally high-order accurate. The two key novelties are that (i) limiting is done by enforcing bounds on quasiconcave functionals; (ii) the bounds that are enforced on the solution at each time step are necessarily satisfied by the low-order approximation.
System of Classification

Perennial or annual herbs or less commonly shrubs, vines, or small trees. Leaves alternate or opposite, simple or pinnately or palmately compound. Flowers axillary or terminal, solitary or in small cymose clusters or dense heads, perfect. Calyx pentamerous, synsepalous, regular or sometimes zygomorphic, wholly herbaceous or with herbaceous lobes and membranous sinuses. Corolla pentamerous, sympetalous, regular or rarely bilabiate, aestivation contorted. Stamens 5, epipetalous, alternate with corolla lobes, the point of insertion varying, anthers 2-celled, dehiscing longitudinally. Ovary superior, inserted on a basal disk, 3-celled, rarely 2- or 4-celled, style single, stigma 3-lobed or rarely 2- or 4-lobed. Fruit a capsule, mostly loculicidal, with 1 to numerous seeds. Seeds mostly with copious endosperm and straight or slightly curved embryo, the seed coat frequently becoming mucilaginous when wet.
The Ambivalent Space(s) of Tourism in Italian Colonial Libya

In the Italian colony of Libya during the course of the 1920s and 1930s there developed an extensive and quite elaborate tourist system that facilitated travel through the Mediterranean coastal region as well as deep into the pre-Saharan interior. This system combined what was among the most advanced networks of transportation and accommodation of any Western colony – providing a level of service that was coincident with or even superior to the standards that could be expected in Italy – along with a number of “authentic” local settings that brought tourists in relatively direct contact with the indigenous populations – in this case offering a vicarious, though entirely safe, experience of the local culture.
Development of a Luminal Esophageal Temperature Monitoring Device for Use During Treatment for Atrial Fibrillation

Author(s): Garner, Scott | Advisor(s): Talke, Frank E | Abstract: Luminal esophageal temperature monitoring is of high importance during catheter-based ablation procedures in the left atrium of the heart. An electrophysiologist’s ability to reliably monitor significant temperature increase created by local ablative heat transfer is crucial to preventing thermal injury of the esophagus. The work presented here describes the initial development of a device intended to accurately measure temperature of the inner esophageal wall during treatment for atrial fibrillation. An experimental setup has been developed using porcine esophageal and left atrial tissue and tests have been performed to better understand heat flow through the biomaterials in contact. To compliment ex vivo experiments, a numerical study using thermal finite element analysis has been implemented to investigate the temperature distribution across tissue layers as a function of tissue thickness, as well as heat source application time. Both the ex vivo study and finite element simulations aid in development of a practical prototype device for potential use during catheter ablation.
Incidence of late effects in long-term childhood cancer survivors.

e22009Background: As therapies for children with cancer have improved, the need for greater attention to adult survivors is becoming more recognized. Our study examined the rates of physician-deter...
Factors influencing burn-out among resident physicians and the solutions they recommend

Residency is a crucial phase of medical training in which trainees acquire the skills and knowledge needed to practise medicine. It has been described as a challenging rite of passage, and in one survey 74% of resident physicians reported they would not recommend their job to their own friends.1 One explanation for this might be found in studies reporting that 76% of internal medicine (IM) resident physicians2 and 65% of emergency medicine (EM) resident physicians3 experience burn-out. Burn-out is defined by Maslach and Jackson (p99)4 as having three key components: ‘(1) increased feelings of emotional exhaustion’; (2) ‘the development of negative, cynical attitudes and feelings about one’s clients’ (eg, patients); and (3) ‘the tendency to evaluate oneself negatively’ (eg, perceptions of poor work performance). One important reason to address the high prevalence of burn-out among resident physicians is due to the association between burn-out with suboptimal patient care2 and patient safety.3 Thomas5 found in her review of 67 studies that the factors associated with burn-out among resident physicians could be divided into three major categories: (1) work-related, (2) demographic and (3) personal. However, almost all published studies have relied exclusively on quantitative survey methods to identify factors related to burn-out. Additionally, resident physicians have not been involved in selecting the interventions used to reduce burn-out. Including the perspective of resident physicians might help to …
Voltage-gated proton channels exist in the plasma membrane of human oocytes

Study question Do human oocytes express voltage-gated proton channels? Summary answer Human oocytes exhibit voltage-gated proton currents. What is known already Voltage-gated proton currents have been reported in human sperm, where they contribute to capacitation and motility. No such studies of human oocytes exist. Study design, size, duration Voltage-clamp studies were undertaken using entire oocytes and vesicles derived from oocytes and in excised patches of membrane from oocytes. Participants/materials, setting, methods Frozen, thawed human metaphase II oocytes were obtained from material donated to the gamete repository at the Rush Center for Advanced Reproductive Care. Prior to patch clamping, oocytes were warmed and equilibrated. Formation of an electrically tight seal requires exposing bare oolemma. Sections of the zona pellucida (ZP) were removed using a laser, followed by repeated pipetting, to further separate the oocyte from the ZP. Patch-clamp studies were performed using the whole-cell configuration on oocytes or vesicles derived from oocytes, and using inside-out patches of membrane, under conditions optimized to detect voltage-gated proton currents. Main results and the role of chance Proton currents are present at significant levels in human oocytes where they exhibit properties similar to those reported in other human cells, as well as those in heterologous expression systems transfected with the HVCN1 gene that codes for the voltage-gated proton channel. Large scale data N/A. Limitations, reasons for caution Human oocytes are large cells, which limits our ability to control the intracellular solution. Subtle effects of cryopreservation by vitrification and subsequent warming on properties of HVCN1, the HVCN1 gene product, cannot be ruled out. Wider implications of the findings Possible functions for voltage-gated proton channels in human oocytes may now be contemplated. Study funding/competing interest(s) NIH R35GM126902 (TED), Bears Care (DM). No competing interests. Trial registration number N/A.
Topological behavior and Zeeman splitting in trigonal PtBi2-x single crystals

Transition-metal dipnictide PtBi2 exhibits rich structural and physical properties with topological semimetallic behavior and extremely large magnetoresistance (XMR) at low temperatures. We have investigated the electrical and magnetic properties of trigonal-phase PtBi2-x single crystals with x ~ 0.4. Profound de Haas–van Alphen (dHvA) and Shubnikov-de Haas (SdH) oscillations are observed. Through fast Fourier transformation (FFT) analyses, four oscillation frequencies are extracted, which result from α, β, γ, and δ bands. By constructing the Landau fan diagram for each band, the Berry phase is extracted demonstrating the non-trivial nature of the α, β, and δ bands. Despite Bi deficiency, we observe the Zeeman splitting in dHvA and SdH oscillations under moderate magnetic field and the moderate Lande g factor (4.97–6.48) for the α band. Quantitative analysis of the non-monotonic field dependence including the sign change of the Hall resistivity suggests that electrons and holes in our system are not perfectly compensated thus not responsible for the XMR effect.
Association of Federal Regulations in the United States and Canada With Potential Corneal Donation by Men Who Have Sex With Men.

Importance Federal policy in the United States prohibits corneal donation by men who have had sex with another man (MSM) in the preceding 5 years, whereas Canada enforces a 12-month ban. The potential consequences of these policies on corneal donations should be evaluated. Objective To estimate the number of potential corneal donations associated with MSM deferral policies in the United States and Canada. Design, Setting, and Participants A nonvalidated telephone survey study was conducted of all 65 eye banks in the United States and Canada to investigate how many potential corneal donors were disqualified in 2018 because of federal MSM restrictions. Published demographic data were also used to arrive at a separate estimate. Survey data were gathered from May 2019 to February 2020. Main Outcomes and Measures Eye banks were asked if they keep records of referrals disqualified specifically because of the federal MSM restrictions and, if so, how many referrals they disqualified in 2018 owing to MSM status. Results Fifty-four of 65 eye banks (83%) responded to the survey, with 30 eye banks reporting they do not keep specific records of MSM deferrals. The remaining 24 eye banks reported disqualifying 360 referrals in 2018 because of MSM status, equating to 720 corneas. The 24 eye banks accounted for 46.2% of corneal donations in the United States and Canada in 2018, yielding an estimate of approximately 1558 corneas rejected that year because of MSM status. A separate estimate using published MSM demographic data indicates that up to 3217 potential corneal donations may have been disqualified in 2018 because of these federal policies. Conclusions and Relevance Findings suggest that between 1558 and 3217 corneal donations were disqualified in 2018 because of federal regulations prohibiting corneal donation by men who have had sex with another man in the preceding 5 years in the United States or 1 year in Canada. With modern virologic testing that is reliable within days of HIV exposure and given the global shortage of corneal tissue, these policies should be reevaluated using current scientific evidence to increase the availability of vision-restoring surgery worldwide.
Hybrid Voltage Balancing Approach for Series-Connected 10 kV SiC MOSFETs for DC-AC Medium-Voltage Power Conversion Applications

This paper focuses on voltage balancing control of series-connected 10 kV SiC MOSFETs for medium-voltage dc-ac power conversion applications. Under ac load current conditions, gate delay time control is used as an example to analyze the limitation of active voltage balancing control methods: 1) active voltage balancing control has a limitation to adjust delay time accurately under a wide-range of load current; 2) the voltage unbalance of body diodes cannot be solved by active voltage balancing control for MOSFETs. For two series-connected 10 kV SiC MOSFETs realized by one half bridge module, the analysis indicates that the unbalance parasitic capacitors inside the power module is the dominant factor causing the voltage unbalance. To achieve voltage balancing control of series-connected SiC MOSFETs and body-diodes, a hybrid approach is proposed in this paper: 1) one small compensation capacitor is applied to balance the non-uniform distribution of package parasitic capacitors inside the power module ; 2) close-loop gate signal turn-off time adjustment is applied to compensate the gate signal error. To verify the proposed balancing approach, a single phase pump-back test is conducted to show the improvement of voltage sharing of both MOSFETs and body-diodes.
Embolic MCA Stroke Treated With tPA and TICI-3 Mechanical Thrombectomy Complicated by Hemiballismus: A Case Study and Literature Review

This report examines the etiology of hemiballistic movements that began 24 hours after a 63-year-old male with vascular risk factors received tissue plasminogen activator (tPa) and thrombolysis in cerebral ischemia 3 (TICI3) thrombectomy for a left middle cerebral artery (MCA) ischemic stroke. The clinical course was reviewed from an admission at a large academic institution where assessments included physical exams, head and neck computed tomography angiography (CTA), and head magnetic resonance imaging (MRI) without contrast. The patient's initial physical exam was consistent with a left MCA syndrome and included a National Institute of Health Stroke Scale (NIHSS) of 20. CTA showed an embolic M2 occlusion. After tPA and TICI 3 thrombectomy, NIHSS improved to 3 for dysarthria, facial weakness, and language deficits. MRI showed left insular diffusion restriction. New right-sided hemiballistic movements began 24 hours after treatment. At his six-week follow-up outpatient appointment, the movements were no longer present, and his neurologic exam was unremarkable, including an NIHSS of zero. No prior cases of hemiballism have been reported as a likely complication of treatment with tPa and thrombectomy. The globus pallidus is the suspected origin of the ballistic movements either from a decreased insular signal or embolic event during treatment. As stroke interventions improve, the susceptibility of certain tissues to brief ischemic events during treatment must be assessed.
Negotiating the Meanings of Adolescent Motherhood Through the Medium of Identity Collages

Responding to flyers posted in high school hallways, and distributed by counselors working at an in-school program for pregnant and parenting teens, the girls gather around a large table strewn with popular magazines, scissors, glue, and poster board. They have come to participate in the Art Project, advertised as an opportunity to meet with other teen mothers for the purpose of discussing their experiences, defining their goals, and exploring their dreams for the future.
Abstract 3272: Heart Failure Disease Management Strategies In Medicare Beneficiaries With Heart Failure Are Cost Effective

Introduction: Clinical trials of heart failure disease management (HFDM) programs have been shown to reduce readmission rates without significant increases in overall cost of care for older patients with heart failure (HF) Hypothesis: We assessed the hypothesis that HFDM versus usual care for Medicare beneficiaries are cost effective. Methods: We performed a cost-effectiveness analysis using a Markov decision analytic model to compare a variety of published HFDM programs versus usual care (UC). Medicare reimbursement data for year 2006 were used to derive estimates for cost of care. Outcomes data were taken from published randomized controlled trials available up to September 2006.HFDM programs were deconstructed and classified based on distinct differences in the components for outpatient care: single home visit (SHV), frequent telephone contact (FTC), increased clinic follow-up (ICF), and extended home care services (EHC). Analyses were conducted from a societal perspective with cost per quality adjusted life year (QALY) as the primary outcome measure. Results: Base-case analyses showed that ICF, EHC and SHV strategies for HFDM had lower costs yet generated more QALYs than UC ie these strategies dominated UC. FTC had higher costs than UC but resulted in more QALYs with incremental cost-effectiveness ratio (ICER) of $16,810 per QALY. Univariate sensitivity analyses showed base case results were insensitive to all parameter variation except for total and readmission costs for ICF, EHC and FTC interventions. Acceptability curves drawn using Monte Carlo simulations showed that no intervention had 90% of simulations below ICER threshold of $50,000/QALY. Conclusion: In conclusion, currently available disease management strategies are economically superior to usual care for Medicare beneficiaries with HF and should be adopted as the standard of care.
Novel Extreme Value Estimation Procedures: Application to Extreme Wind Data

The past two decades have seen the development of a large body of extreme value theory based on the application of the Generalized Pareto Distribution (GPD) to the excess of the extreme variate over a fixed threshold. For sufficiently large values of the extreme variates, the GPD with tail length parameters c > 0 and c < 0 is equivalent, respectively, to the Type II (Frechet) and Type III (reverse Weibull) distribution of the largest values. The Type I (Gumbel) distribution is equivalent to the limit of the GPD as c→0. Owing to these equivalences, the GPD can be used to model extreme data obtained by either the ’peaks over threshold’ approach or the epochal approach.
Building the Civic Community in Geopolitically Fragmented Communities

A constant challenge for every community is to engage residents in the civic life of the community. The challenge is particularly acute in rural environments where geopolitical fragmentation (counties divided into multiple governmental units) often provides barriers to meaningful civic engagement and in urban areas where socioeconomic fragmentation and social anonymity isolate residents from meaningful civic interaction. The program “What Makes This Community Tick?” offers extension educators a good model to draw citizens into the civic life of their communities.
Oxidation Catalysis by Transition Metal Complexes

Oxidation catalysis is reviewed with emphasis on radical versus nonradical pathways, autoxidation, and mechanistic studies. Bioinorganic model catalysts are discussed, including the distinction between monooxygenase and dioxygenase pathways. Some organic synthetic applications as well as applications to green chemistry are discussed. Finally some organometallic oxidation catalysts are discussed. Keywords: epoxidation; asymmetric catalysis; hydroxylation; peroxides; oxygen
Deformation of Nonstoichiometric CuO Polycrystals

The current interest in fabrication methods for high-temperature superconductors has fostered heightened interest in the precursor materials. It has been shown that the reaction kinetics for formation of Bi2Sr2CaCu2Ox, (Bi, Pb)2Sr2Ca2Cu3Ox, and YBa2Cu3Ox are related to the copper oxide precursor through both the particle size of the starting powder1 and the oxidation state,2, 3 with finer CuO powders reacting faster. Many proposed fabrication methods include a high-temperature mechanical working step during the reaction process.4, 5 However, little is known about the diffusional and mechanical properties of CuO at the fabrication temperatures of interest. The literature indicates only that the electrical conductivity of CuO is independent of oxygen partial pressure (P02).6, 7 Therefore, only intrinsic ionization occurs in CuO. Thus, for a given temperature, the concentrations of electrons and holes are fixed.
Undersaturation of inert gases at the ocean surface: A thermal pumping mechanism

[1] A diurnal ‘thermal pumping’ mechanism is proposed to explain why undersaturation of inert gases may develop at the sea surface during extended periods of low wind speed and net warming. A simple two-layer model of the upper ocean with parameterized air-sea gas exchange is used to explain the process. The model predicts maximum undersaturations of 0.25% for Ne, 0.75% for N2, 0.88% for Ar, and 1.12% for Kr for an assumed diurnal warming signal of 2°C, a gas transfer rate appropriate to a wind speed of 4 ms−1, and the simplifying assumption of no net warming over the day. The model results depend on the air-sea gas transfer rate and the details of the upper ocean heating and mixing cycle. Observations of N2 undersaturation from the tropical Atlantic provide supporting experimental evidence.
Specific transcriptional inhibition of bone marrow-derived macrophage tumor necrosis factor-alpha gene expression and protein production using novel enantiomeric carbocyclic nucleoside analogues.

Tumor necrosis factor-alpha (TNF-alpha) is a powerful macrophage-derived proinflammatory cytokine, via both direct effects on host tissues as well as indirectly through the induction of other proinflammatory mediators, including interleukin- (IL) 1 beta and IL-6. Activation of murine bone marrow-derived macrophages (BMDM phi) with lipopolysaccharide (LPS) causes rapid expression of TNF-alpha, which as an autocrine factor enhances BMDM phi function through IL-1 beta and IL-6 production. In this study, we have examined the specific transcriptional inhibition of BMDM phi TNF-alpha using novel enantiomeric carbocyclic nucleoside analogues. BMDM phi were derived in vitro from murine bone marrow progenitors using colony stimulating factor-1 and treated with combinations of LPS (1-100 nG/ml) and the enantiomeric carbocyclic nucleoside (10-100 microM) analogues MDL 201, 112 (9-[(1S,3R)-cis-cyclopentan-3-ol]adenine); MDL 201,451 (9-[1R,3S)-cis-cyclopentan-3-ol]adenine); MDL 201,449 (9-[(1R,3R)-trans-cyclopentan-3-ol]adenine) and MDL 201,484 (9-[(1S,3S)-trans-cyclopentan-3-ol]adenine). Northern blot analysis showed that MDL 201,449 was the most effective agent in vitro at selectively inhibiting TNF-alpha. MDL 201,449 reduced TNF-alpha mRNA levels by nearly 50% for up to 4 hr after the simultaneous addition of LPS and the synthetic agent. In contrast, mRNA and secreted protein levels for IL-1 beta (measured by the D10.S bioassay) and mRNA for TNF-alpha receptor p60 and TNF-alpha receptor p80 were not significantly affected. Carbocyclic nucleoside analogues were effective when added to BMDM phi up-to 2 hr after LPS treatment and at concentrations as low as 10 microM. Regulation of BMDM phi IL-6 by carbocyclic nucleoside analogues in response to LPS appears to be both concentration and time dependent, because IL-6 mRNA and secreted protein levels were inhibited at only high drug concentrations (100 microM) and effective only at longer exposure times (+4 hr of incubation) to LPS. These data support the concept that M phi-derived proinflammatory cytokine gene expression is differentially, rather than coordinately, regulated by selective signal transduction and/or molecular pathways. Enantiomeric carbocyclic nucleoside analogues that specifically inhibit TNF-alpha may have therapeutic potential in inflammatory diseases, such as systemic inflammatory response syndrome, where TNF-alpha has been shown to have an important role in initiating the early stages of disease.
Essentials of noninvasive cardiac stress testing

AbstractPurpose:To provide advanced practice nurses (APNs) with practice recommendations for noninvasive cardiac stress testing (NCST) to enhance diagnostic test selection and to improve the interpretation of the test results.Data sources:A review and synthesis of current scientific literature on no
Intrastriatal transplantation of bone marrow nonhematopoietic cells improves functional recovery after stroke in adult mice

The authors transplanted adult bone marrow nonhematopoietic cells into the striatum after embolic middle cerebral artery occlusion (MCAO). Mice (n = 23; C57BL/6J) were divided into four groups: (1) mice (n = 5) were subjected to MCAO and transplanted with bone marrow nonhematopoietic cells (prelabeled by bromodeoxyuridine, BrdU) into the ischemic striatum, (2) MCAO alone (n = 8), (3) MCAO with injection of phosphate buffered saline (n = 5), and (4) bone marrow nonhematopoietic cells injected into the normal striatum (n = 5). Mice were killed at 28 days after stroke. BrdU reactive cells survived and migrated a distance of approximately 2.2 mm from the grafting areas toward the ischemic areas. BrdU reactive cells expressed the neuronal specific protein NeuN in 1% of BrdU stained cells and the astrocytic specific protein glial fibrillary acidic protein (GFAP) in 8% of the BrdU stained cells. Functional recovery from a rotarod test (P < 0.05) and modified neurologic severity score tests (including motor, sensory, and reflex; P < 0.05) were significantly improved in the mice receiving bone marrow nonhematopoietic cells compared with MCAO alone. The current findings suggest that the intrastriatal transplanted bone marrow nonhematopoietic cells survived in the ischemic brain and improved functional recovery of adult mice even though infarct volumes did not change significantly. Bone marrow nonhematopoietic cells may provide a new avenue to promote recovery of injured brain.
Ice nucleation temperature influences recovery of activity of a model protein after freeze drying

Abstract The objective of this study was to determine whether a relationship exists between ice nucleation temperature and recovery of activity of a model protein, lactate dehydrogenase, after freeze drying. Aqueous buffer systems containing 50 µg/mL of protein were frozen in vials with externally mounted thermocouples on the shelf of a freeze dryer, then freeze dried. Various methods were used to establish a wide range of ice nucleation temperatures. An inverse relationship was found between the extent of supercooling during freezing and recovery of activity in the reconstituted solution. The data are consistent with a mechanism of inactivation resulting from adsorption of protein at the ice/freeze–concentrate interface during the freezing process. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:3495–3498, 2009
The genesis of RNA interference, its potential clinical applications, and implications in gynecologic cancer.

Abstract Objective. This review will discuss the discovery and development of RNA interference (RNAi) technology, small interfering RNA (siRNA) design and delivery, and the implications of RNAi on gynecologic cancers. Methods. Systematic review of English language literature using searches for RNAi and gynecologic cancers in established databases, including Pubmed and Ovid, was employed. Results. The high degrees of efficiency and specificity are the main advantages of RNAi. Consequently, RNAi is used in functional genomics and developing therapies for the treatment of viral infection, dominant disorders, neurological disorders, and cancers, including gynecologic cancers. Conclusion. RNAi represents an exciting technology for functional genomics by selective targeting of genes. While issues regarding delivery remain, the therapeutic advantages of siRNA in cancer treatment warrant further investigation.
Fidelity of supported employment: lessons learned from the National Evidence-Based Practice Project.

Purpose To describe the implementation of supported employment in the National Evidence-Based Practices Project, examining and interpreting fidelity changes over two years of program implementation. Method Nine new supported employment programs were evaluated by examining supported employment fidelity ratings at baseline and every 6 months thereafter. Site reports based on the nine case studies were used to interpret the fidelity findings. Results At two years, eight of nine sites achieved high fidelity. Most changes occurred within the first year. Twelve of the 15 supported employment fidelity items showed rapid improvement. Discussion A review of the site reports suggested four factors that facilitated movement toward high fidelity: (1) Discontinuing non-evidence-based vocational services, (2) Making rapid structural changes through administrative action, (3) Measuring key process indicators to move toward desired changes, and (4) Gradually improving integration of the employment specialists with clinical services, primarily through supervisor leadership.
Integral-C—a practical environment for C programming

Integral C1 is an industrial grade integrated programming environment for C programming on an engineering workstation. A single interactive tool replaces a syntax checking editor, a compiler, and a source-level debugger. Its multi-window user interface allows program editing and animated source level debugging, tailored to the needs of a C programmer. The compiler accepts standard C code and reacts to editing changes with function-level incremental compilation. Compilation is done without prompting to maintain the client program in a ready-to-run state. Emitted code is instrumented to catch run-time errors and to permit fine grained debugging. Debugging support code is written in C in a 'workspace', which grants it direct access to a local scope while keeping it separate from the client program.
THE STANDARDIZED LETTER OF RECOMMENDATION: IMPLICATIONS FOR SELECTION

In an effort to standardize academic application procedures, the Standardized Letter of Recommendation (SLR) was developed to capture important cognitive and noncognitive qualities of graduate school candidates. The SLR consists of seven scales (knowledge, analytical skills, communication skills, motivation, self- organization, professionalism and maturity, and teamwork) and was applied to an intern-selection scenario. Both professor ratings (N = 414) during the application process and mentor ratings of the selected students (N = 51) after the internship was completed were collected using the SLR. A multidimensional Rasch investigation suggests that the seven scales of the SLR displayed satisfactory psychometric properties in terms of reliability, model fit, item fit statistics, and discrimination. The two cognitive scales, knowledge and analytical skills, were found to be the best predictors for intern selection. The professor ratings and mentor ratings had moderate to high correlations, with the professor ratings being systematically higher than the mentor ratings. Possible reasons for the rating discrepancies are discussed. Also, implications for how the SLR can be used and improved in other selection situations are suggested.
Small Area Silicon Diffused Junction X-Ray Detectors

The low temperature performance of silicon diffused junction detectors in the measurement of low energy x-rays is reported. The detectors have an area of 0.04cm2 and a thickness of 100?m. The spectral resolutions of these detectors were found to be in close agreement with expected values indicating that the defects introduced by the high temperature processing required in the device fabrication were not deleteriously affecting the detection of low energy x-rays. Device performance over a temperature range of 77°K to 150°K is given. These detectors were designed to detect low energy x-rays in the presence of miniumum ionizing electrons. The successful application of silicon diffused junction technology to x-ray detector fabrication may facilitate the development of other novel silicon x-ray detector designs.
Aqueous Ln(III) luminescence agents derived from a tasty precursor.

The synthesis, aqueous stability and photophysical properties are reported for a novel tetradentate ligand derived from maltol, a commonly used flavor enhancer. In aqueous solution, this chelate forms stable complexes with Ln(III) cations, and sensitized emission was observed from Eu(III), Yb(III), and Nd(III). A comparison with recently reported and structurally analogous ligands reveals a slightly higher basicity but lower complex stability with Eu(III) [pEu = 14.7 (1)]. A very poor metal centered quantum yield with Eu(III) was observed ({Phi}{sub tot} = 0.04%), which can be rationalized by the similar energy of the ligand triplet state and the Eu(III) {sup 5}D{sub 0} emissive level. Instead, sensitized emission from the Yb(III) and Nd(III) cations was observed, which emit in the Near Infra-Red (NIR).
Managing new and differentiated remanufactured products

We study a firm that makes new products in the first period and uses returned cores to make remanufactured products (along with new products) in future periods. The remanufactured product is differentiated from the new product, so the firm needs to choose differentiated prices. We analyze the monopoly environment in two-period, multi-period (three, four and five) and infinite planning horizons, and characterize the optimal remanufacturing and pricing strategy for the firm. In the process, we identify remanufacturing savings thresholds that determine the production and pricing strategy for the firm. Among other results, we find—counter to intuition—that in a finite-horizon, multi-period setting, the optimal policy is not necessarily monotone in remanufacturing savings.
K-shell ionization cross sections by electron bombardment at low energies

Abstract Measurements have been made of the total cross sections for ionization of the K-shell by bombarding thin foil targets with 50 keV electrons from a gun in the case of the elements Ti, Cr, Ni and Cu. The corrections for electrons reflected by the substrate were performed using a bipartition model of electron transport. The results are compared with the theoretical calculations and the earlier experimental results.
The relationship between age, size, and reproduction in Trillium grandiflorum (Liliaceae)

The relative importance of age and size as predictors of demographic parameters such as survivorship or reproductive status is generally unknown for herbaceous perennials, due primarily to the difficulty in estimating the age of herbaceous plants. We investigated the relationship between age, size, and reproductive status in Trillium grandiflorum, a rhizomatous perennial herb in which age can be estimated. We measured the leaf area and rhizome volume and estimated the age of plants in a study population that included reproductive and nonreproductive individuals. Reproductive plants were significantly older (X = 22.8 years) than nonreproductive plants (X = 13.3 years). Reproductive plants also had significantly larger total leaf areas and rhizome volumes. Total leaf area, rhizome volume, and age were positively correlated in both groups. Reproduction in this population occurred once plants reached a threshold leaf area or rhizome volume. Both measures of plant size, i.e., total leaf area and rhizome volume, were better predictors of plant reproductive status than was plant age. Numerous studies of annual, biennial, and monocarpic perennial plants suggest that plant size is frequently a
DETERMINATION OF NON-THERMAL VELOCITY DISTRIBUTIONS FROM SERTS LINEWIDTH OBSERVATIONS

Non-thermal velocities obtained from the measurement of coronal Extreme Ultraviolet (EUV) linewidths have been consistently observed in solar EUV spectral observations and have been theorized to result fro m many plausible scenarios including wave motions, turbulence, or magnetic reconnection. Constraining these velocities can provide a physical limit for the available energy resulting from unresolved motions in the corona. We statistically determine a series of non-thermal velocity distributions from linewidth measurements of 390 emission lines from a wide array of elements and ionization states observed during the Solar Extreme Ultraviolet Research Telescope and Spectrograph 1991-1997 flights covering the spectral range 174-418 A and a temperature range from 80,000 K to 12.6 MK. This sample includes 248 lines from active regions, 101 lines from quiet-Sun regions, and 41 lines were observed from plasma off the solar limb. We find a strongly peaked distribution corresponding to a non-thermal velocity of 19-22 km/s in all three of the quiet-Sun, active region, and off-limb distributions. For the possibility of Alfven wave resonance heating, we find thai velocities in the core of these distributions do not provide sufficient energy, given typical densities and magnetic field strengths for the coronal plasma, to overcome the estimated coronal energy losses required to maintain the corona at the typical temperatures working as the sole mechanism. We find that at perfect efficiency 50%-60% of the needed energy flux can be produced from the non-thermal velocities measured.
Comparison of four numerical algorithms for solving the Liapunov matrix equation

This paper summarizes four alternative methods for computing the solution to the Liapunov matrix equation. A comparison of the methods is presented, along with sample computer runs. The necessity for solving this equation arises not only in certain phases of nonlinear stability analysis, but also in the design of optimal systems with fixed control structures. A more general form of this equation, which often appears in structural analysis, can be handled directly by one of the methods, and by the others with minor modifications.
Quantum well infrared photodetectors - recent advances at NRC

Recent advances on quantum well infrared photodetectors (QWIP) at the National Research Council Canada are reviewed. These include the demonstration of QWIP-LED pixelless imaging, the development of THz, ultrafast, and two-photon QWIPs.
Nonlinear Characterization of Thin Films by the Dual-Arm Z-scan Method

We report nonlinear refraction and absorption of organic (polymethine) and semiconductor (ZnO) thin films on thick substrates using the dual-arm Z-scan method to remove the substrate signals, thus allowing the discrimination of very small signals.
Characterization of pisatin-inducible cytochrome p450s in fungal pathogens of pea that detoxify the pea phytoalexin pisatin.

Many fungi that are pathogenic on pea have the ability to demethylate and thus detoxify the pea phytoalexin pisatin. This detoxification reaction has been studied most thoroughly in Nectria haematococca MP VI where it functions as a virulence trait. The enzyme catalyzing this reaction [pisatin demethylase (pda)] is a cytochrome P450. In the current study, the induction of whole-cell pda activity and the biochemical properties of pda in microsomal preparations from the pea pathogens Ascochyta pisi, Mycosphaerella pinodes, and Phoma pinodella are compared to the pda produced by N. haematococca. Based on cofactor requirements and their inhibition by carbon monoxide, cytochrome P450 inhibitors, and antibodies to NADPH:cytochrome P450 reductase, we conclude that the pdas from the other pea pathogens also are cytochrome P450s. All of the enzymes show a rather selective induction by pisatin, have a low K(m) toward pisatin, and have a fairly high degree of specificity toward pisatin as a substrate, suggesting that each pathogen may have a specific cytochrome P450 for detoxifying this plant antibiotic. Since the pdas in these fungi differ in their pattern of sensitivity to P450 inhibitors and display other minor biochemical differences, we suggest that these fungi may have independently evolved a specialized cytochrome P450 as a virulence trait for a common host.
Characteristics of gold/cadmium sulfide nanowire Schottky diodes

Abstract Schottky diode junctions were formed between nanowires of cadmium sulfide and nanowires of gold, through sequential cathodic electrodeposition into the pores of anodized aluminum oxide (AAO) templates. Lengths of CdS and Au nanowires were 100–500 nm and 300–400 nm respectively, while the diameter was 30 nm, each. Analysis of Schottky diodes yielded an effective reverse saturation current (Jo), of 0.32 mA/cm2 and an effective diode ideality factor (A) of 8.1 in the dark. Corresponding values under one sun illumination were, Jo = 0.92 mA/cm2 and A = 10.0. Dominant junction current mechanisms are thought to be tunneling and/or interface state recombination.
Relative contribution of trunk muscles to the stability of the lumbar spine during isometric exertions

Abstract Objective. To compare the relative contribution of various trunk muscles to the stability of the lumbar spine. Design. Quantification of spine stability with a biomechanical model. Background. Modern low back rehabilitation techniques focus on muscles that stabilize the lumbar spine. However, the relative contribution of various trunk muscles to spine stability is currently unknown. Methods. Eight male subjects performed isometric exertions in trunk flexion, extension, lateral bending, and axial rotation, and isometric exertions under vertical trunk loading and in a lifting hold. Each isometric trial was repeated three times at 20%, 40%, and 60% of the maximum trunk flexion force or with a load of 0%, 20%, 40%, and 60% of body weight for the latter two exertions. Surface EMG data from 12 major trunk muscles were used in the biomechanical model to estimate stability of the lumbar spine. A simulation of each trial was performed repeatedly with one of the 10 major trunk muscle groups removed from the model. Results. Relative contribution of each muscle to spine stability was significantly affected by the combination of loading magnitude and direction (3-way interaction). None of the removed muscles reduced spine stability by more than 30%. Conclusions. A single muscle cannot be identified as the most important for the stability of the lumbar spine. Rather, spine stability depends on the relative activation of all trunk muscles and other loading variables. Relevance This study will improve our understanding of individual trunk muscles' contribution to overall stability of the lumbar spine.
The electroencephalogram in cases of subdural hematoma and hydroma.

Abstract The EEG findings in 32 patients with subdural effusion are reported. Twenty-four of these were unilateral subdural hematomas, 4 were bilateral hematomas, and 4 were unilateral hydromas. The EEG abnormalities were of two types: (A) suppression of alpha activity on the side of the lesion in 13 of the 24 unilateral hematomas and in 2 of the unilateral hydromas; (B) slow wave activity of either low or increased voltage, which occurred in 11 of the unilateral lesions and 3 of the bilateral ones. The slow activity characteristically was irregular, from 1 to 5 per sec. and non-paroxysmal in character. Suppression of alpha activity was a specific effect and was best demonstrated between electrodes closely spaced in an anterior-posterior line. In 5 anteriorly placed hematomas suppression of alpha activity was encountered. Spiking did not occur; and sharp waves were rare. The EEG gave a correct lateralization in 75 per cent of the cases and a correct localization on the side indicated in 47 per cent. The EEG did not distinguish between unilateral and bilateral subdural accumulations. Only 4 per cent of the group showed normal EEG's with subdural hematoms; whereas EEG's from 2 of the 4 patients with unilateral hydromas were normal. A total figure of 90 per cent abnormality was encountered in the entire group. The data reported agree very well with other reviews and cases reports in the literature.
Thermodynamic properties, magnetism and Mott–Hubbard-like transitions in nanoscale clusters

Abstract The charge–spin response thermodynamics in the presence of a magnetic field are calculated using analytical diagonalization of small clusters. Rigorous criteria for the Mott–Hubbard, Neel and zero-field (spin) weak pseudogap singularities ( crossovers ) in the thermodynamic charge and spin density of states are found for the first time in the exactly solvable two- and four-site Hubbard ( U ⩾ 0 ) clusters. These exact calculations of the chemical potential, magnetization, charge and spin susceptibilities show the presence of true Mott–Hubbard (charge), antiferromagnetic (spin) and zero-field (spin) ground state gaps and pseudogaps that develop at infinitesimal temperatures. These pseudogaps exist in a limited range of temperature or/and doping levels and disappear at the critical temperatures of crossovers ( bifurcations ), reminiscent of the pseudogaps and normal-state phase diagram in the high T c cuprates.
Market theory and moral theory in health policy.

Recent efforts to introduce competition, consistent with microeconomic theory, into the United States health care system raise questions of distributive justice. Similarities between microeconomic theory and libertarian philosophy suggest the possibility of confusing economic goals of efficiency and cost containment with social goals of equity of access to care. This paper raises the fear that if the two are confused, society may unwittingly abandon any serious effort to ensure that the poor have access to essential types of medical care, because libertarian philosophy cannot justify placing any constraints, however beneficient, on the actual distribution of benefits and burdens of illness resulting from free trade.
Trophic ecology of striped bass, Morone saxatilis, in a freshwater reservoir (Lake Texoma, U.S.A.)

Many vertebrate predators consume a wide variety of prey types, depending upon availability and vulnerability. In contrast, striped bass, Morone saxatilis, that have been introduced to Lake Texoma (Oklahoma-Texas, U.S.A.) use a very limited array of fish (mostly clupeids of the genus Dorosoma) as prey. As a large, mobile predator, M. saxatilis should be capable of capturing and consuming numerous other species of fish that are available in the reservoir. However, examination of 1845 stomachs year-around over 5 years showed that the only marked ‘switching’ among prey was from Dorosoma to a diet including a high percentage of insects during spring–early summer, ignoring most other fish taxa that could have served as food. Even under essentially starvation conditions in late summer of years with scarce Dorosoma, M. saxatilis in Lake Texoma did not switch to other available fish as prey. Patterns of predation by M. saxatilis are trenchantly different from place to place: very narrow prey selectivity even under starvation conditions has been reported once previously for the species in a freshwater reservoir, but in its native marine and estuarine environment and in some other reservoirs the species is more catholic in its use of prey. Why this large predator shows fidelity in some environments to particular prey, even to the extent of starvation, remains an enigma.
Itch, Eosinophils, and Autoimmunity: A Novel Murine Model of Bullous Pemphigoid

Mice carrying a deletion in the NC14A domain of murine type XVII collagen begin scratching at age 2 months and then develop erosions, subepidermal vesicles, eosinophil-rich skin infiltrates, and autoantibodies directed against a 180 kDa skin protein that appears to be type XVII collagen. These mice represent a bullous pemphigoid animal model featuring pruritus in immunocompetent, mature, and largely unmanipulated animals.
Comparative skeletal mass and radial bone mineral content in black and white women

The age-related changes in both skeletal mass and muscle mass were directly measured in normal black women ages 30 to 80 yr. The levels of total-body calcium (TBCa) were determined with the use of in vivo neutron activation. The muscle mass was measured by whole-body counting of /sup 40/K. In the same population, the bone mineral content of the radius was measured using a photon absorptiometric technique. Although there was no significant difference in stature, black women had a greater skeletal mass and bone mineral content of the radius than age-matched white female subjects. When the TBCa values were normalized for body size (i.e., corrected for height and lean body mass), the TBCa was still higher for the black women but not as high as the absolute TBCa values. Clearly, it is the larger muscle mass (as reflected by the /sup 40/K measure) in relation to weight and height that accounts for this difference. The lower prevalence of fracture and osteoporosis observed in black women relative to white women is due in part to this greater quantity of skeleton. American black women with a higher bone density (i.e., skeletal mass) maintain mechanical integrity of the skeleton longer than individuals withmore » a lower bone density. It is suggested that the larger muscle mass in black women is, in part, a determinant of their increased skeletal mass and is partly responsible for their apparent resistance to osteoporosis and fracture of the skeleton.« less