cssi/SciSciGPT-SciSciNet huggingface dataset:
Can a 3D task transfer function accurately represent the signal transfer properties of low-contrast lesions in non-linear CT systems?

The purpose of this study was to investigate how accurately the task-transfer function (TTF) models the signal transfer properties of low-contrast features in a non-linear CT system. A cylindrical phantom containing 24 anthropomorphic liver lesions (modeled from patient lesions) was designed using computer-aided design software (Rhinoceros 3D). Lesions had irregular shapes, 2 sizes (523, 2145 mm3), and 2 contrast levels (80, 100 HU). The phantom was printed with a state-of-the-art multimaterial 3D printer (Stratasys J750). CT images were acquired on a clinical CT scanner (Siemens Flash) at 4 dose levels (CTDIVol, 32 cm phantom: 1.5, 3, 6, 22 mGy) and reconstructed using 2 FBP kernels (B31f, B45f) and 2 iterative kernels (SAFIRE, strength-2: I31f, and I44f). 3D-TTFs were estimated by combining TTFs measured using low-contrast rod inserts (in-plane) and a slanted edge (z-direction) printed in-phantom. CAD versions of lesions were blurred by 3D-TTFs and virtually superimposed into corresponding phantom images using a previously validated technique. We compared lesion morphometry (i.e., size and shape) measurements between 3D printed “physical” and TTF-blurred “simulated” lesions across multiple acquisitions. Lesion size was quantified using a commercial segmentation software (Syngo.via). Lesion shape was quantified by measuring the Jaccard index between the segmented masks of paired physical and simulated lesions. The relative volume difference D between physical and simulated lesions was mostly less than the natural variability COV of the physical lesions. For large and small lesions, the COV1,&#119896;,&#119897; was greater or similar to D&#119896;,&#119897; in 12 and 13 out of 16 imaging scenarios, respectively. Simulated and physical lesion shapes were similar, with an average simulated-physical Jaccard index of 0.70 (out of max value of unity). These results suggest 3D-TTFs closely models the signal transfer properties of linear and non-linear CT conditions for low-contrast objects.
F211. Finding and fixing attentional dysfunction in schizophrenia

Background Schizophrenia is the most debilitating health problem that exists, and its cognitive impairments are the greatest predictor of disability. Since the earliest clinical descriptions of the illness, abnormalities of attention have been at the core of the cognitive symptoms of schizophrenia. Theories of attentional dysfunction in schizophrenia propose that the deficits arise from either an inability to maintain working memory representations that guide attention, or difficulty focusing lower-level visual attention mechanisms. However, these theoretical accounts neglect the role of long-term memory representations in controlling attention.
Phenotypic changes and DNA methylation status in cryopreserved seeds of rye (Secale cereale L.).

Abstract Conserving genetic diversity is a major priority of the National Laboratory for Genetic Resources Preservation (NLGRP), operated by the U.S. Department of Agriculture, Agricultural Research Service. There are two long-term preservation methods employed in the NLGRP: storage in a −18 °C freezer (conventional storage) and storage in liquid nitrogen vapor phase at −135 to −180 °C (cryopreservation). To test the phenotypic and epigenetic effects of long-term cryopreservation of orthodox seeds, we evaluated 40 cereal rye accessions (20 spring habit and 20 winter habit) stored for 25 years under both conventional storage and cryogenic conditions. In laboratory evaluations of winter habit rye, seeds from cryopreserved samples had significantly higher normal germination percentage (P
Representing Design Objects in SORAC

In this paper, we apply our experience in developing ArchObjects, an intelligent architectural design system, towards the development of a general data modeling language appropriate for design representations. An adequate design representation language is crucial to the ability to reason about designs. Current object-oriented and semantic data models are not well-suited to complex design domains, however. The built-in relationship types of the traditional semantic data models do not adequately support the needs of design applications nor do they provide adequate behavioral support. Although object-oriented models are popular, and provide encapsulation of behavior, these do not support built-in relationships or reuse of relationship semantics. Neither model includes constraints, which are a fundamental concept in ArchObjects and other intelligent design systems. To solve these problems, we are building SORAC, an object-oriented model with semantic relationships and constraints. This model has several major features. Relationships are represented as objects, with a relationship class hierarchy. In addition, relationship classes are derived from a core set of semantic relationships by selecting certain semantic options. Complex constraints are also represented as objects; these are constraints over several relationships and can represent domain knowledge such as fire safety codes. First, we discuss the requirements imposed on this data model from the design domain. Next, we present the core semantic relationships of SORAC, optional semantics, and an overview of the data modeling language. Finally, some examples of using relationship semantics to simplify triggering and evaluation of domain constraints are presented.
Probabilistically Shaped 8-PAM Suitable for Data Centers Communication

We study non-uniform 8-PAM signaling schemes, based on Maxwell-Boltzmann and exponential source distributions, as candidates suitable for data centers’ communications. We evaluate mutual information of these schemes against corresponding uniform 8-PAM scheme, for different parameters of source distributions. The properly chosen variable parameters for different SNR-regions allows us to closely approach Shannon limit, and to significantly outperform the corresponding uniform counterpart. We demonstrate that LPDC-coded 8-PAM with exponential distribution outperforms the LDPC-coded 8-PAM with uniform distribution of the same achievable information rate by 1.8 dB, and this improvement is comparable to that obtained from mutual information calculations.
Latent Tuberculosis and Current Health Disparities in California: Making the Invisible Visible.

Tuberculosis (TB) continues to have devastating consequences for patients both globally and locally, with disease risk concentrated in specific subgroups defined by race, ethnicity, and nativity. W...
To Tie or Not to Tie: A Systematic Review of Postaxial Polydactyly and Outcomes of Suture Ligation Versus Surgical Excision:

Background: Ulnar polydactyly is frequently encountered in the newborn nursery and is commonly treated with bedside suture ligation. However, growing concern about the complications associated with suture ligation has led some practitioners to advocate for primary surgical excision instead. Thus, we set out to compare outcomes of suture ligation and surgical excision by systematic appraisal of the literature. Methods: Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, a systematic review was performed to identify studies published between 1950 and 2017 that described outcomes of suture ligation, surgical excision, or both. Baseline characteristics, complications, and study quality were extracted for each included article. Results: A total of 900 articles were reviewed, of which 10 studies (8 case series, 2 comparative analyses) met the inclusion criteria. There was considerable heterogeneity among the studies with respect to patient characteristics and reported outcomes. There were 2 retrospective case series of suture ligation that reported no acute complications and a variable proportion of patients with residual remnants or neuromas. Studies evaluating surgical ligation reported no acute or long-term complications, with only 1 case series reporting a small percentage of residual remnants. However, in the largest cohort analysis, the difference in complication rate was reported to be as high as 23.5% for suture ligation compared with 3% for surgical excision. Conclusions: There is a paucity of literature limiting the comparison of suture ligation and surgical excision for ulnar polydactyly. Further studies are required to determine the optimal treatment.
In vivo measurements of irreversible and reversible transverse relaxation rates in human basal ganglia at 7 T: making inferences about the microscopic and mesoscopic structure of iron and calcification deposits.

The goal of this study was to measure irreversible and reversible transverse relaxation rates in the globus pallidus and putamen at 7 T, and to use these rates to make inferences about the sub-voxel structure of iron and calcification deposits. Gradient Echo Sampling of a Spin Echo (GESSE) data were acquired at 7 T on eighteen volunteers spanning a large range of ages (23-85 years), with calcifications in the globus pallidus incidentally observed in one volunteer. Maps of transverse relaxation rates were derived from the GESSE data, and the mean value of these rates in globus pallidus and putamen was estimated for each volunteer. Both irreversible and reversible transverse relaxation rates increased with the expected age-dependent iron content in these structures, except for the individual with calcifications for whom extremely large reversible relaxation rates but normal irreversible relaxation rates were found in the globus pallidus. Given the sensitivity of irreversible and reversible transverse relaxation rates to microscopic and mesoscopic field variations, respectively, our findings suggest that joint consideration of these rates may yield information not only about the amount of iron and calcification deposited in the brain, but also about the sub-voxel structure of these deposits, perhaps revealing certain aspects of their geometry and cellular distribution.
Practical Application of Aspiration as an Outcome Indicator in Extension Evaluation.

Extension educators need simple and accurate evaluation tools for program evaluation. This article explains how to use aspiration as an outcome indicator in Extension evaluation and introduces a practical evaluation tool. Aspiration can be described as the readiness for change. By recording participants' levels of aspiration, we will be able to determine whether the program is effective in achieving desired results. This aspiration-recording tool is easy to use in terms of data collection, analysis, and interpretation. Evaluation data collected from this tool can be used to document accountability and make decisions for program modifications.
Sound and robust solid modeling via exact real arithmetic and continuity

Algorithms for solid modeling, i.e., Computer-Aided Design (CAD) and computer graphics, are often specified on real numbers and then implemented with finite-precision arithmetic, such as floating-point. The result is that these implementations do not soundly compute the results that are expected from their specifications. We present a new library, StoneWorks, that provides sound and robust solid modeling primitives. We implement StoneWorks in MarshallB, a pure functional programming language for exact real arithmetic in which types denote topological spaces and functions denote continuous maps, ensuring that all programs are sound and robust. We developed MarshallB as an extension of the Marshall language. We also define a new shape representation, compact representation (K-rep), that enables constructions such as Minkowski sum and analyses such as Hausdorff distance that are not possible with traditional representations. K-rep is a nondeterminism monad for describing all the points in a shape. With our library, language, and representation together, we show that short StoneWorks programs can specify and execute sound and robust solid modeling algorithms and tasks.
The efficacy of obesity polygenic risk scores in an autistic population

Polygenic risk scores (PRS) bear great promise in understanding complex diseases and improving clinical diagnoses, but the competency of these risk scores in different populations is known to vary significantly, especially between those of European ancestry and those of other ethnic ancestries. However, the applicability of these risk scores across populations different by disease, instead of ethnicity, is poorly understood. A current and largely unexplored population for the accuracy of PRS is that of individuals with autism. Combined with the increased prevalence of obesity in autistic populations, we seek to evaluate the difference in efficacy of PRS for obesity in autistic versus non-autistic populations. We show that genetic variants strongly associated with obesity in non-autistic populations are significantly less representative of the disease in autistic populations. Rather, these cases of obesity phenocopies in patients with autism may follow a different and non-conventional mechanism of action involving the regulation of oxytocin in the brain among other potential behavioral factors. Our findings elucidate the limits of PRS across populations contrasting by disease and suggest that obesity may be regulated differently in individuals with autism as compared to those without autism.
Development of a Low-Cost Electrical Impedance-Based Microflow Cytometer

Sickle Cell Disease (SCD) is a genetic condition caused by a mutated hemoglobin molecule (HbS) found in red blood cells (RBCs). HbS polymerizes in low oxygen environments and contribute to painful vaso-occlusion in patients. Laboratory diagnosis of SCD is typically made by detection of the presence of sickle cells by peripheral blood smear, and presence of HbS by electrophoresis and high-performance liquid chromatography. Recently, flow cytometry technique in companion with sickling assays has demonstrated the capability in quantitative measurements of sickle cells at single-cell level, using software algorithm for cell-imaging analysis (Van Beers et. al. American Journal of Hematology 2014), and electrical impedance (Liu et. al. Sensors and Actuators B: Chemical 2018). Here, we show a portable, cost-efficient electrical impedance-based sensor and its capability to be used in conjunction with microfluidics-based sickling assay for microflow cytometry of sickle cells. The impedance microflow cytometer is based on a commercially available integrated circuit (IC), the AD5933. Using a microcontroller and additional circuitry on a custom designed printed circuit board, we are able to produce sinusoidal signals of up to 100kHz in frequency and sample up to 200 data points per second, at a cost under $60 in materials to create. The impedance measurement range is optimized to work in companion with microfluidic chips in general. In order to measure sickle cells, the impedance microflow cytometer is used in companion with our unique Polydimethylsiloxane (PDMS) microfluidic cell sickling assay (Du et. al. PNAS 2014). Cells are suspended in phosphate buffered saline (PBS) medium and move in the microchannel using a pressure driven flow. Impedance measurement is achieved using two Ti/Au electrodes embedded in the microchannel as cells flow past the electrodes. Data is captured and made available for post processing using a customized MATLAB script. RBCs from healthy donors and SCD patients were used to demonstrate the capability of the developed system. The results showed that our system can separate between normal RBCs and sickle cells, as well as between sickled and unsickled cells. The performance in detection of sickle cells is comparable to a commercial impedance analyzer. This proof-of-concept design aims to minimize the physical space needed for cytometry as well as bring affordable and reliable cytometry results within its given limitations. Download : Download high-res image (229KB) Download : Download full-size image Figure . Disclosures Alvarez: Forma Therapeutics: Consultancy; Novartis: Consultancy.
Is the Glass Always Half Full? Examining the Relationship Between Dispositional Optimism and Risky Decision Making

Dispositional optimism is considered a stable personality trait and as such may influence expectations about outcomes in a variety of decision-making scenarios. The current study assessed the relationship between dispositional optimism and decision-making behavior when risk is present. To investigate whether optimism was associated with risky decision-making behavior, we examined the relationships between dispositional optimism and two correlates (attributional style and trait hope) and risk-taking behavior on the Iowa Gambling Task (IGT) for 61 participants (Mage = 19.62). Correlational analyses between the three measures of optimism and IGT performance indicate that dispositional optimism and risky decision-making behavior are not significantly related to one another. This study contributes to the literature examining how individual differences influence decision-making. A broader perspective on the factors that influence decision making is necessary so that the mechanisms that predict and explain risky decision making can be better understood. Keywords: dispositional optimism, decision making, risk, attributional style, hope, Iowa Gambling Task
Neuroimaging and the localization of function in visual cognition

Several recent studies have interpreted multivariate evidence for stimulus-specific patterns of activity in parietal and/or frontal cortex as evidence for a representational function in those regio...
A structure-function study of C-terminal residues predicted to line the export channel in Salmonella Flagellin.

Abstract Background Structural studies of a Salmonella Typhimurium flagellin protein indicated that four polar or charged C-terminal amino acid residues line the inner channel of the flagellum. The hydrophilic character of these putative channel-lining residues was predicted to be essential to facilitate the transport of unfolded flagellin monomers during flagellar assembly. The structure-function relationship of these putative channel-lining residues was investigated by site-directed mutagenesis to examine effects of side chain polarity and size on flagella assembly and function. Methods Channel-lining residue variants were generated using site-directed mutagenesis to substitute alanine and other residues to examine the effects of altered side-chain polarity on export and assembly. The export, in vivo motility function, and flagellar structure of variants was characterized by agar motility, video microscopy, immunofluorescence, and SDS-PAGE. Results Alanine substitution yielded decreased motility and flagellar assembly for three of the four residues. However, alanine substitution of residue Arg 494 did not alter export, although substitution with negatively charged glutamate decreased motility and flagellar filament length. Furthermore, many of the C-terminal mutations affected flagellar filament morphology and stability, often resulting in more tightly coiled and/or more brittle flagella than the wild type. Conclusions The four channel-lining C-terminal residues may facilitate monomer protein transport but also have structural roles in determining the stability and morphology of the flagellum. General significance These results provide further insight into the complex process of bacterial flagellin export and flagellar assembly and provide evidence of previously unknown structural functions for the four putative channel-lining residues.
Predicting protein secondary structure by an ensemble through feature-based accuracy estimation

Protein secondary structure prediction is a fundamental task in computational biology, basic to many bioinformatics workflows, with a diverse collection of tools currently available. An approach from machine learning with the potential to capitalize on such a collection is ensemble prediction, which runs multiple predictors and combines their predictions into one, output by the ensemble. We conduct a thorough study of seven different approaches to ensemble secondary structure prediction, several of which are novel, and show we can indeed obtain an ensemble method that significantly exceeds the accuracy of individual state-of-the-art tools. The best approaches build on a recent technique known as feature-based accuracy estimation, which estimates the unknown true accuracy of a prediction, here using features of both the prediction output and the internal state of the prediction method. In particular, a hybrid approach to ensemble prediction that leverages accuracy estimation is now the most accurate method currently available: on average over standard CASP and PDB benchmarks, it exceeds the state-of-the-art Q3 accuracy for 3-state prediction by nearly 4%, and exceeds the Q8 accuracy for 8-state prediction by more than 8%. A preliminary implementation of our approach to ensemble protein secondary structure prediction, in a new tool we call Ssylla, is available free for non-commercial use at ssylla.cs.arizona.edu.
Inclusion in limited distribution drug network reduces time to dalfampridine access in patients with multiple sclerosis at a health-system specialty pharmacy.

BACKGROUND: Dalfampridine improves walking speed in patients with multiple sclerosis (MS), but accessing specialty medications such as dalfampridine can be hindered by insurance restrictions, high ...
Labor productivity forecasts based on a Beveridge–Nelson filter: Is there statistical evidence for a slowdown?

Abstract In this paper, I assess the evidence for a structural break in labor productivity growth in the years before the Great Recession with the use of out-of-sample forecasting exercises for the years 2010 to 2019 and the recently developed Beveridge–Nelson filter. Models based on a Beveridge–Nelson filter with no structural breaks outperform those allowing for a structural break, and there is statistically significant evidence that they outperform the random walk, though all models were too optimistic about labor productivity growth. Recently developed statistical tests do point to the presence of a structural break before the Great Recession, but uncertainty about the data-generating process for labor productivity growth or the timing and magnitude of the break may be too great to be helpful in forecast preparation.
The Haiti Reader: History, Culture, Politics: Edited by Laurent Dubois, Kaiama L. Glover, Nadève Ménard, Millery Polyné, and Chantalle F. Verna

Dubois, Laurent, Kaiama L. Glover, Nadeve Menard, Millery Polyne, and Chantalle F. Verna, eds. The Haiti Reader: History, Culture, Politics. Durham, NC: Duke University Press, 2020.
Computer Teaching of Strabismus

Traditional methods of teaching strabismus diagnosis and management to orthoptists, ophthalmology residents and practitioners include lectures, conferences, a home study course, books and journals....
U(1) symmetric α-attractors

We present a class of supergravity α-attractors with an approximate global U(1) symmetry corresponding to the axion direction. We also develop a multi-field generalization of these models and show that the α-attractor models with U(1) symmetries have a dual description in terms of a two-form superfield coupled to a three-form superfield.
An analysis of the impact of school closings on gifted services: Recommendations for meeting gifted students’ needs in a post-COVID-19 world

Gifted support services were directly impacted by the COVID-19 shutdown in Spring 2020. This qualitative research study consisting of parents (n = 110) and gifted support teachers (n = 53) explored the impact on gifted students? services and instruction. Utilizing surveys, open-ended response questions, and in-depth interviews, teachers and parents shared their thoughts and perceptions about challenge, enrichment, and students? social-emotional health throughout the shutdown. Data analysis found that gifted services were directly impacted by the COVID-19 shutdown and parents and teachers shared that challenge and enrichment were lacking. However, data collected also showed that there is much potential to meet students? academic and social-emotional needs virtually. Utilizing the data collected, a model was created to help teachers, parents, and school districts provide challenge, enrichment, and acceleration, as well as address social-emotional concerns in a virtual environment.
Lifetime Depth Profile Measurement Method in Heavily Doped Semiconductors Using Electron Beams

A method for depth profiling the minority carrier lifetime of heavily doped semiconductors is described. The technique utilizes an electron beam to generate electron hole pairs as a function of depth. By utilizing an exact numerical model for the semiconductor current flow equations, the minority carrier lifetime as a function of depth can be determined.
The Structure of the Muscle Protein Complex 4Ca2+·Troponin C·Troponin I

Analysis of scattering data based on a Monte Carlo integration method was used to obtain a low resolution model of the 4Ca2+·troponin C·troponin I complex. This modeling method allows rapid testing of plausible structures where the best fit model can be ascertained by a comparison between model structure scattering profiles and measured scattering data. In the best fit model, troponin I appears as a spiral structure that wraps around 4Ca2+·troponin C which adopts an extended dumbbell conformation similar to that observed in the crystal structures of troponin C. The Monte Carlo modeling method can be applied to other biological systems in which detailed structural information is lacking.
Prenatal exposure to metronidazole and risk of childhood cancer: a retrospective cohort study of children younger than 5 years.

BACKGROUND To evaluate the role of in utero exposure to metronidazole (a carcinogen in some animal models) and the risk of subsequent cancer, the authors conducted a retrospective cohort study of childhood cancer. METHODS The cohort included 328,846 children younger than 5 years born to women enrolled in Tennessee Medicaid at any time between the last menstrual period (LMP) and the date of delivery. The cohort was identified by linking files of Tennessee Medicaid mothers ages 15-44 years and children and the children's birth and death certificates for the period January 1, 1975 through December 31, 1992. Exposure data were obtained from Medicaid pharmacy records and exposure was defined as filling a metronidazole prescription that had at least a day's supply between the 30 days prior to the LMP and the date of delivery. Study cases were cohort children diagnosed with a first primary cancer before age 5 years, identified by linking the cohort with a statewide childhood cancer database for the study period. RESULTS Cohort members contributed 1,172,696 person-years of follow-up for analysis, with children exposed (8.1%) and not exposed (91.9%) in utero to metronidazole contributing 79,716 and 1,092,980 person-years, respectively. Of 952 children younger than 5 years in the statewide cancer database, 175 met study eligibility criteria. Of these, 42 had leukemia, 30 had central nervous system (CNS) tumors, 28 had neuroblastoma, and 75 had other cancers. Using Poisson regression modeling, children exposed to metronidazole in utero had no significant increase in adjusted relative risk (RR) for all cancers (RR: 0.81; 95% confidence interval [95% CI], 0.41-1.59), leukemia (no exposed case), CNS tumors (RR: 1.23; 95% CI, 0.29-5.21), neuroblastomas (RR: 2.60; 95% CI, 0.89-7.59), and other cancers (RR: 0.57; 95% CI, 0.18-1.82). CONCLUSIONS The authors conclude that although there was no increase in risk for all cancers associated with in utero exposure to metronidazole, the observed increased risk for neuroblastomas, although not significant, requires further evaluation. Cancer 1998;83:1461-1468. © 1998 American Cancer Society.
Organic Enrichment of the Seafloor; Impact Assessment Using a Geographic Information System

Two state-of-the-art techniques involving computer analysis are used in the study of pollution impact assessment. A synoptic survey of Narragansett Bay (USA), conducted in 1988, is presented as an example. A REMOTS® camera, an optical instrument that photographs vertical in-situ profiles of the upper 20 cm of the sediment, was deployed at 56 stations throughout the Bay. REMOTS® sediment-profile images were analyzed with SAIC Image Analysis Software that allows systematic measurement of up to 21 seafloor variables (e.g. modal grain-size, apparent RPD depth). Gradient maps of REMOTS® parameters, as well as bathymetry and traditional measurements of dissolved oxygen, vertical salinity differences, and sediment densities of Clostridium perfringens (a microbial indicator of fecal pollution) were digitized and transferred to a Geographic Information System (GRASS). Diverse overlay analysis tools within GRASS allowed us to identify severely degraded sites in the upper Bay. Areas at risk could also be defined in the mid Bay. Advantages of such a protocol are discussed.
Some Low-Angle X-Ray Evidence on the Structural Changes in Thermally- and Plasma-Treated Wool:

A series of events occurred when wool was heated in vacuum. At some stages structural changes in the thermally-treated wool were observed, as reflected in the low-angle x-ray diffraction patterns. An increase in the intensity of the 39 A meridional reflection and the appearance of a 4-point diagram with azimuthal angle of 45° at about 46 A spacing were observed when wool was heated near 170°C for 90 min. Similar results were found in samples heated at higher temperatures but for shorter time. The most heat-resistant meridional reflection is the 66 A.The low-angle x-ray diffraction patterns of plasma-treated wool showed only disappearance of the sharp lipid ring at 48 A. No intensification of any reflection was observed. Prolonged treatment with plasma destroys the low-angle x-ray diffraction pattern of wool.
From trusted to secure: building and executing applications that enforce system security

Commercial operating systems have recently introduced mandatory access controls (MAC) that can be used to ensure system-wide data confidentiality and integrity. These protections rely on restricting the flow of information between processes based on security levels. The problem is, there are many applications that defy simple classification by security level, some of them essential for system operation. Surprisingly, the common practice among these operating systems is simply to mark these applications as "trusted", and thus allow them to bypass label protections. This compromise is not a limitation of MAC or the operating system services that enforce it, but simply a fundamental inability of any operating system to reason about how applications treat sensitive data internally--and thus the OS must either restrict the data that they receive or trust them to handle it correctly. These practices were developed prior to the advent security-typed languages. These languages provide a means of reasoning about how the OS's sensitive data is handled within applications. Thus, applications can be shown to enforce system security by guaranteeing, in advance of execution, that they will adhere to the OS's MAC policy. In this paper, we provide an architecture for an operating system service, that integrate security-typed language with operating system MAC services. We have built an implementation of this service, called SIESTA, which handles applications developed in the security-typed language, Jif, running on the SELinux operating system. We also provide some sample applications to demonstrate the security, flexibility and efficiency of our approach.
λ cro Represser complex with OR3 operator DNA: 19F nuclear magnetic resonance observations

Abstract The interaction of λ cro represser with DNA is probed using synthetic 17 base-pair O R 3 operators in which 5-fluorodeoxyuridine has been systematically incorporated at each of the nine positions normally occupied by a thymidine residue. By monitoring changes in chemical shift of the fluorine resonances upon cro represser binding in aqueous buffers of varying 2 H 2 O content, we have examined the specific cro repressor-O R 3 DNA complex in detail. The results are interpreted in the context of the popular model for cro repressor-O R 3 complex derived from the three-dimensional structure of the cro repressor in the absence of DNA. The results presented here not originally predicted by the model are: (1) there is an asymmetry in the environment at the two ends of the operator, although the base-pairs involved and the cro repressor dimer are symmetric; (2) there appears to be distortion of the DNA helix at two distinct positions; (3) changes of the DNA environment in the middle of the helix suggest additional DNA distortion not near the contact areas proposed in the model.
A Method for Determining Crack Opening Load from Load-Displacement Data

The fatigue crack opening load is determined as the tangent point on the ascending load-displacement data between the curved portion and the upper linear region. A model for the 'unzipping' behavior of the crack indicates that the curved portion of the load-deflection curve is second order. The opening load is determined by a nonlinear, least squares fit of the data to the model, which optimally locates the tangent point of the two curves. The method provided consistent results for determining opening load P(op) for 7475-T731 aluminum using data from a crack tip opening gage.
Polysaccharide That May Serve as a Carbon and Energy Storage Compound for Sporulation in Bacillus cereus

An intracellular, glucose-containing polysaccharide accumulates in Bacillus cereus early in sporulation and is degraded at the time of spore maturation. This pattern of accumulation and degradation occurred when growth was limited by glucose or a component of yeast extract. These data suggest that the polysaccharide may be serving as a carbon and energy storage compound for sporulation. A somewhat similar pattern of accumulation and degradation of poly-β-hydroxybutyric acid (PHB) was shown earlier by Kominek and Halvorson (1965) to occur in Bacillus cereus. When cells were grown in a medium buffered strongly at pH 7.4, however, very little accumulation of PHB occurred. We have found that polysaccharide accumulates in cells grown in both the strong and weakly buffered media. Perhaps polysaccharide is the major carbon and energy storage compound when cells are grown under conditions preventing significant accumulation of PHB. The lack of polysaccharide accumulation during the exponential phase of growth may be an indication that the needed biosynthetic enzymes are controlled by catabolite repression during growth. The polysaccharide was purified and found to consist of glucose. The iodine absorption spectrum suggests a degree of branching between that of glycogen and amylopectin.
Computers in hospitals nursing practice defined and validated

Computers in hospitals offer Nursing a unique challenge to define and validate its own practice. This definition will begin first within those hospitals implementing computer systems with nursing applications. These first pioneers must take great care to develop application content that reflects valid nursing roles and to communicate to each practitioner the standards of practice which will guide the planning and delivery of quality nursing care.
Liver impairment in the obese.

Summary 1.Eighteen obese subjects were studied. All but 1 had abnormal liver function tests. Bromsulphalein retention was the most consistently abnormal test. 2.Needle biopsy of the liver was performed in 12 patients. All but 1 had abnormal histologic findings. 3.Eleven of 17 patients had diabetic type glucose tolerance tests. 4.There was no correlation between the degree of liver impairment and abnormal glucose tolerance tests. 5.Weight reduction is associated with reduction in liver impairment.
Cesarean deliveries for medicaid patients: a comparison in public and private hospitals in Los Angeles county.

Abstract Objective: The aims of the study were to describe the difference in cesarean delivery rates for Medicaid patients according to hospital type and adjusted for case mix and to determine cost implications for additional cesarean deliveries. Study Design: This retrospective study used California discharge data for 92,800 patients delivered in 78 hospitals in Los Angeles County during 1991. Multivariable logistic regression was used to adjust for case mix and to calculate adjusted cesarean delivery rates according to hospital type. Cost estimates assumed $821 per day hospital reimbursement. Results: The unadjusted cesarean delivery rate in private nonteaching hospitals (reference group) was 24.5%, compared with 13.2%, 17.4%, and 16.5% in public, health maintenance organization, and private teaching hospitals, respectively. Adjustment for case mix decreased the cesarean delivery rate in public (9.0%), health maintenance organization (12.0%), and private teaching hospitals (8.0%). Cesarean deliveries performed on patients in private nonteaching hospitals result in an additional $13.6 million in Medicaid health care expenses. Conclusions: There are increased health care costs related to increased cesarean deliveries performed on Medicaid patients in private nonteaching hospitals. (Am J Obstet Gynecol 1999;180:1177-84.)
Oxatriquinane and oxatriquinacene: extraordinary oxonium ions.

Oxatriquinane, a fused, tricyclic alkyl oxonium ion of unprecented stability, was synthesized in five steps from 1,4,7-cyclononatriene. It survives reflux in H2O, chromatography, and attack by alcohols, alkyl thiols, halide ions, and hindered amine bases. The X-ray crystal structure shows longer C−O bond distances and more acute C−O−C bond angles than any reported alkyloxonium salt. The corresponding oxatriquinene and oxatriquinacene were also synthesized and represent the first examples of stable allyl oxonium species.
Isomer shift reference scales

The relative isomer shift values of materials commonly used as source and absorber standards for 17 common Mossbauer transitions have been evaluated. This data allows the comparison of isomer shifts among various laboratories despite differences in standards used as zero velocity standards.
Endocrine studies in 8 patients with dystrophia myotonica.

DYSTROPHIA myotonica (also called myotonia atrophica) is a relatively rare disease of unknown etiology. In addition to the myotonia the disease is often characterized clinically by cataracts, baldness, hypometabolism and testicular atrophy. It is therefore understandable that various endocrine factors should have been implicated as being causally important. However, objective evaluation of these factors has been incomplete. In the past five years, 8 patients with dystrophia myotonica have been studied in a special effort to evaluate the endocrinologic aspects of this disease. An attempt has been made to study the functions of the thyroid, parathyroid, adrenal, gonadal and pituitary glands. METHODS The basal metabolic rate was determined in the accepted manner, using a standard type Benedict-Roth closed circuit respiration apparatus. In patients having several basal metabolism tests, the lowest value was accepted as the most valid. The total blood cholesterol concentration was determined by the method of S...
ENUMERATION OF FRESHWATER PHYTOPLANKTON CONCENTRATED ON THE MEMBRANE FILTER1

Individuals of the phytoplankton become distributed at random when concentrated on the membrane filter. The percentage of microscopic fields in which a species occurs may therefore be validly converted to a theoretical average number of individuals per field. The theoretical density thus obtained and the actual density determined by time-consuming counting are very nearly similar values when 25 or more fields are scored. An enumeration technique using this relationship is described. It has many advantages over commonly used procedures for concentrating the plankton and estimating the number of individuals in a sample.
A STUDY OF PLASMA PROTEIN ALTERATIONS IN RABBITS INFECTED WITH TYPE I PNEUMOCOCCI

An investigation of the plasma protein changes in rabbits infected intradermally with Type I pneumococci has been carried out, utilizing a cationic detergent method of protein fractionation. A consistent pattern of change was observed. There was an increase in the alpha globulins and fibrinogen concentration which reached maximal levels at the height of the infection. Albumin fell to a minimal concentration when the increment of alpha globulins and fibrinogen was greatest. The beta-gamma concentration showed a significant decrease during the most severe phase of the infection but returned to normal several days after spontaneous subsidence of bacteremia. The magnitude of these plasma protein alterations depended on the severity of the infection and the response of the host. Significantly greater changes were observed in rabbits severely bacteremic than in those with mild bacteremia. Administration of penicillin suppressed the infection and decreased the usual plasma protein alterations. Injection of cortisone prior to the onset of the Type I pneumococcus infection caused an early inhibition of the expected plasma protein changes, but later the protein pattem developed in the same manner as it did in the severely infected animals.
Preliminary experience with monoenergetic photon mammography

We are using a beam port at the National Synchrotron Light Source Facility at Brookhaven National Laboratory as a source of monoenergetic photons. The photon source is radiation from a bending magnet on the x-ray storage ring and provides a usable x-ray spectrum from 5 keV to over 50 keV. A tunable crystal monochromotor is used for energy selection. The beam is 79 mm wide and 0.5 mm high. We imaged the ACR mammography phantom and a contrast-detail phantom using a phosphor plate as the imaging detector. Phantom images were obtained at 16, 18, 20, and 22 keV. Phantom thickness varied from 15 mm to 82 mm. These images were compared to images obtained with a conventional dedicated mammography unit. Subjective preliminary results show that image contrast of the monoenergetic images is similar to those obtained from the conventional x-ray source with somewhat sharper and cleaner images from the monoenergetic source. Quantitative analysis shows that the monoenergetic images have improved contrast compared to the polyenergetic derived images. Entrance skin dose measurements show a factor of 5 to 10 times less radiation for the monoenergetic images with equivalent or better contrast. Although there remain a number of technical problems to be addressed and much more work to be done, we are encouraged to further explore the use of monoenergetic imaging.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Monocytes in Sterile Inflammation: Recruitment and Functional Consequences

Monocytes play an important role in initiating innate immune responses. Three subsets of these cells have been defined in mice including classical, nonclassical and intermediate monocytes. Each of these cell types has been extensively studied for their role in infectious diseases. However, their role in sterile injury as occurs during ischemia–reperfusion injury, atherosclerosis, and trauma has only recently been the focus of investigations. Here, we review mechanisms of monocyte recruitment to sites of sterile injury, their modes of action, and their effect on disease outcome in murine models with some references to human studies. Therapeutic strategies to target these cells must be developed with caution since each monocyte subset is capable of mediating either anti- or pro-inflammatory effects depending on the setting.
Evidence and modeling of paired ions and other loss mechanisms in erbium-doped silica fibers

To explain the sub-optimal performance of erbium-doped resonant fiber lasers and superfluorescent fiber sources observed experimentally, the effects of potential loss mechanisms are explored via computer simulations. Pump excited-state absorption (ESA) at 980 nm and 1.48 micrometers , and signal ESA are unable to explain the dependence of the observed effects on concentration. Cooperative upconversion among uniformly distributed erbium ions fails to explain the observed reduction in source slope efficiency with increasing concentration. On the other hand, rapid cross-relaxation between paired ions, which might form in high concentration fibers, can produce the observed dependences. Rate equations for paired ions are used to understand their saturation behavior and their effect on the slope and threshold of fiber sources. Methods to assess the fraction of paired ions are discussed. Measurements suggest that about 18% of the ions in an aluminum co-doped silica fiber with 5 X 10 19 Er 3+ /cm 3 are paired. The effects of paired ions on the gain of Er-doped fiber amplifiers are also briefly discussed.
On requirements for software fault tolerance for flight controls

The need for the application of software fault tolerance techniques in digital flight control systems is argued to follow from the requirements derivable from the safety constraints of such systems, requirements which can be stated in terms of minimum acceptable system reliability levels and, moreover, stated quantitatively. It is argued further that, while fault tolerance appears to be a viable mechanism in general, individual fault tolerance schemes need to be analyzed to ensure that they are adequate to the task and being properly utilized, that such analysis is essentially an exercise in software 'reliability' estimation involving software characteristics not currently included in software 'reliability' modeling (most especially, the degree of correlation of malfunctions among redundant, dissimilar software modules), and that, consequently, further research and studies in the characterization of software behavior and malfunctions is required.
The light : nutrient ratio in lakes: a test of hypothesized trends in bacterial nutrient limitation

The light-to-nutrient hypothesis explores how the balance between energy (as light energy) and nutrients (as total phosphorus) shapes aquatic ecosystem structure and process. The balance of energy and nutrients is thought to regulate ecosystem structure and process such that, in a “high” light-to-nutrient environment, bacteria would probably be driven towards phosphorus (P) limitation, whereas, in a “low” light-to-nutrient environment, bacteria would be driven towards carbon (C) limitation. We assessed the growth limitation of bacteria in two reservoirs of the southern U.S.A. using a mortality-corrected dilution-growth approach. We compared the frequency of P and C growth limitation with the intralake variation in the light-to-nutrient environment. As a metric of the light-to-nutrient environment, we used the ratio of the mean light in the surface mixed layer (Im) to the total phosphorus concentration (TP ). In each lake, bacterial growth was more often P-limited when the Im : TP ratio was above the median ratio than below. We believe our data provide the first evidence supporting this aspect of the light-to-nutrient hypothesis.