cssi/SciSciGPT-SciSciNet huggingface dataset:
Virtual timeline: a formal abstraction for verifying preemptive schedulers with temporal isolation

The reliability and security of safety-critical real-time systems are of utmost importance because the failure of these systems could incur severe consequences (e.g., loss of lives or failure of a mission). Such properties require strong isolation between components and they rely on enforcement mechanisms provided by the underlying operating system (OS) kernel. In addition to spatial isolation which is commonly provided by OS kernels to various extents, it also requires temporal isolation, that is, properties on the schedule of one component (e.g., schedulability) are independent of behaviors of other components. The strict isolation between components relies critically on algorithmic properties of the concrete implementation of the scheduler, such as timely provision of time slots, obliviousness to preemption, etc. However, existing work either only reasons about an abstract model of the scheduler, or proves properties of the scheduler implementation that are not rich enough to establish the isolation between different components. In this paper, we present a novel compositional framework for reasoning about algorithmic properties of the concrete implementation of preemptive schedulers. In particular, we use virtual timeline, a variant of the supply bound function used in real-time scheduling analysis, to specify and reason about the scheduling of each component in isolation. We show that the properties proved on this abstraction carry down to the generated assembly code of the OS kernel. Using this framework, we successfully verify a real-time OS kernel, which extends mCertiKOS, a single-processor non-preemptive kernel, with user-level preemption, a verified timer interrupt handler, and a verified real-time scheduler. We prove that in the absence of microarchitectural-level timing channels, this new kernel enjoys temporal and spatial isolation on top of the functional correctness guarantee. All the proofs are implemented in the Coq proof assistant.
Necking and drawing of rubber–plastic laminate composites: Finite element simulations and analytical model

Abstract Many plastics show necking and drawing behavior in tension, sometimes called “cold drawing”. In contrast, elastomers stretch homogeneously in tension. We examine the tensile behavior of rubber–plastic laminate composites using 3D finite element simulations and an analytical model. A rate-independent constitutive behavior was adopted in which the modulus at small-strain, strain hardening at large strain, and yield stress (only for the plastic) can all be varied independently. For sufficiently small rubber/plastic thickness ratio, layered composites show necking and drawing wherein a tensile bar coexists in two strain states, one with a large stretch (necked region) and the other with a modest stretch (unnecked region). With increasing rubber/plastic thickness ratio, the two strain states approach each other in a manner resembling a second order phase transition culminating in a critical point. Above this critical rubber/plastic thickness ratio, the layered composites stretch homogeneously. An analytical model based on adding the First Piola–Kirchoff stresses of the rubber and plastic layers, along with a modification for inelastic deformation, is shown to capture most of the results of 3D simulations accurately. We comment on the practical relevance of these results to toughening relatively brittle plastics, and more specifically, the critical importance of strain hardening of the rubber.
Tibiometry: A non-invasive in vivo method for testing the strength of the tibia

Publisher Summary Testing bone strength in the living subject should be useful in evaluating the treatment and progress of metabolic bone disease. The results could be used as a basis of comparison amongst study groups as well as for long-term evaluation of individual patients and could be used to assess the effects of disease, the effectiveness of treatment, the adverse side effects in treatment of non-osseous disease and the consequences of physiological stress, such as diving and space flight. Investigators and clinicians rely on indirect and semi-quantitative methods, such as radiography, gamma absorption, biopsy, neutron activation, and mineral balance studies; however, at present, there is no reliable, non-invasive, in vivo method of testing bone strength. It is because the tests on human subjects must be safe, non-invasive and painless, while bones are mostly deeply buried in soft tissue and not accessible for mechanical testing. A method for in vivo human bone testing has been developed. Most technical obstacles have been cleared, and the technique is fast approaching the threshold of clinical applicability.
Turn-Taking in Shakespeare

Dr. Oliver Morgan, at the end of Turn-taking in Shakespeare, writes “This book has been a success if it sends the reader back to Shakespeare with a heightened sensitivity to dramatic dialogue—more ...
Efavirenz versus Protease Inhibitors in Patients with HIV: A Systematic Review and Meta-Analysis

Efavirenz- and protease inhibitor (PI)-based regimens remain viable options across the globe. We conducted a meta-analysis to compare the effectiveness of efavirenz-based regimens relative to PI-based regimens. EMBASE, PubMed, Cochrane, and clinicaltrials.gov were searched for randomized controlled trials conducted between 1987 and 2018 comparing efavirenz- with PI-based regimens. This was followed by title, abstract, and full-text screens. The quality of selected studies was assessed using the Cochrane risk of bias tool. Meta-analysis of the odds of virological suppression was conducted using the robust variance estimation approach. Fifteen studies met the inclusion criteria and totaled 6712 patients (efavirenz arm = 3339; PI arm = 3373), of which 1610 (24.0%) were females. Follow-up ranged from 24 to 144 weeks. Mean/median age ranged from 33 to 44 years. Mean/median baseline CD4 count ranged from 32 to 557 cells/mL while mean/median baseline viral load ranged from log10 4.5 to log10 5.5 copies/mL. Meta-analysis showed that patients receiving efavirenz-based regimens had 37% higher odds of virological suppression compared to PI-based regimens (odds ratio = 1.37, 95% confidence interval = 1.06-1.77, p = 0.02). The Egger test suggested the presence of publication bias (B = 0.927, t = 2.214, p = 0.033). The main threat to the quality of evidence was attrition bias. Regarding virological suppression, efavirenzbased regimens were more effective than PI-based regimens and, therefore, might be ideal for the management of treatment naive patients with HIV in settings where NNRTIs and PIs are used.
Stress Physiology and Physiometrics

Psychological stressors, including acute stressors such as public speaking, short-term stressors such as exam periods, and long-term stressors such as caregiving have all been associated with changes in physiological systems. Much of the literature relating psychological stress and physiology has ignored how physiometrics—the reliability and validity of physiological parameters and biomarkers—might affect the estimation of relationships between these parameters and measures of stress. Acute physiological reactivity to experimental stress can serve as a meaningful predictor of future health outcomes and disease risk. Biomarkers used in studies of stress and other psychosocial variables have a wide range of variability. Cortisol, for example, does not generalize well from one day to the next, but if multiple days are collected at each time point, stability over weeks to months is low to moderate. Every study of stress physiology should use sufficiently reliable and generalizable measurement to avoid misestimation and both Type I and Type II errors.
Diminished Protective Effects of Household Income on Internalizing Symptoms among African American than European American Pre-Adolescents.

Aim: To investigate the differential role of race on the effect of household income on pre-adolescents’ internalizing symptoms in a national sample of U.S. pre-adolescents. Methods: This is a cross-sectional study that used data from the Adolescent Brain Cognitive Development (ABCD) study. Wave 1 ABCD data included 5,913 adolescents between ages 9 and 10 years old. The independent variable was household income. The primary outcome was internalizing symptoms measured by the teacher report of the Brief Problem Monitor (BPM) scale. Results: Overall, high household income was associated with lower levels of pre-adolescents internalizing symptoms. Race showed statistically significant interaction with household income on pre-adolescents’ internalizing symptoms, controlling for all confounders, indicating weaker protective effect of high household income on internalizing symptoms for African American than European pre-adolescents. Conclusion: High household income is a more salient protective factor against internalizing symptoms of socially privileged European American pre-adolescents than of historically marginalized African Americans pre-adolescents. Elimination of internalizing behavioral gaps across racial groups requires more than equalizing socioeconomic status. Future research should study the moderating role of institutional and structural racism experienced by African American families across all income levels. Such research may explain why pre-adolescent African Americans with high household income remain at high risk of internalizing symptoms.
Efficient Transition from a Traditional Planar Transmission Line to a Topological Line Wave

An efficient design for coupling energy from a traditional planar microwave transmission line to a topological metasurface line wave is presented. An antipodal slotline is used as the starting transmission line, which is then coupled to the metasurface along a specific point that maximizes field matching. Additional modifications to the interface between the two structures improves the coupling further. A simulated loss analysis isolates the effect of the transitions from the rest of the structure, showing a $S_{21}$ contribution of only −0.28 dB/transition. The choice of transition allows for broadband operation, with less than −0.5 dB/transition $S_{21}$ contribution over most of the operating region of the metasurface. This efficient design is the first effort to integrate topologically robust metasurface transmission lines to traditional microwave systems, opening the door to future uses of such structures in practical systems.
Genomic Heterogeneity of Aggressive Pediatric and Adult Diffuse Astrocytomas

Glioblastoma, formerly known as glioblastoma multiforme (GBM), is remarkable for its degree of both morphologic and genomic heterogeneity. In children and adults, as defined by the World Health Organization (WHO), GBM is a grade IV neoplasm with a diffusely infiltrative growth pattern populated by cells showing predominately astrocytic differentiation. As discussed in previous chapters, GBM features prominent nuclear atypia and cellular pleomorphism, as well as high tumor cell mitotic activity accompanied by microvascular proliferation and/ or necrosis. As its former name indicates, GBM may include one or many morphologic patterns within a single tumor. In some tumors, this reflects underlying clonal evolution with newly acquired genetic changes in tumor cell subpopulations. Even more variable than GBM morphology is the range of genomic heterogeneity, creating multiple molecular signatures that define tumor behavior, prognosis and treatment response independent of tumor histopathology. Furthermore, while pediatric and adult glioblastoma share many histopathologic similarities, they are unequivocally biologically distinct neoplasms. In many pediatric and adult gliomas, the molecular subgroup is a better predictor of tumor behavior than histologic grade. In particular, WHO grade II or III diffuse astrocytomas lacking morphologic features associated with GBM (microvascular proliferation and necrosis), but with certain defined molecular alterations, should be considered GBM for prognostic and therapeutic purposes due to their expected WHO grade IV-like behavior. The focus of this chapter centers on the genomic heterogeneity and pathobiology of aggressive pediatric and adult diffuse astrocytomas with WHO grade IV behavior independent of morphologic features.
A qualitative study on the impact of long-distance travel for gynecologic cancer care.

Abstract Background Women with gynecologic malignancies experience improved clinical outcomes when they are treated by gynecologic oncologists and in high-volume cancer centers. However, geography is a major barrier to high-volume care for patients. This qualitative study was undertaken to identify facilitators and barriers to patients traveling long distances for gynecologic cancer care. Methods Semi-structured interviews were conducted with 19 women with gynecologic malignancies traveling >50 miles for treatment at Wake Forest Comprehensive Cancer Center. Eight interviews included caregivers. Four interview domains focused on personal challenges and coping strategies related to accessing cancer care. Results Mean distance traveled for care was 87 miles (range: 54–218). Most participants reported that recommendations from physicians, friends, and family motivated travel. 10/19 participants were aware of closer sites for cancer care; 5 had unfavorable experiences elsewhere. Barriers to travel included time, cost, childcare, difficulty navigating, and physical discomfort. Social support was an important facilitator of travel for care; some patients utilized loaned money or vehicles. Participants reported significant energy expenditure scheduling travel, coordinating time off work, and arranging overnight stays near the cancer center. Suggestions for care improvement included travel vouchers, transportation assistance, signage and personnel to help with navigation, and appointments later in the day. Participants supported in-person oncologist outreach to rural areas and appointments via telemedicine; few preferred the current infrastructure. Conclusion Patients who travel long distances for gynecologic cancer care encounter significant burdens and rely heavily on social and financial support. Interventions should be developed and evaluated to reduce the burden of long-distance travel and develop efficient methods of outreach, including telemedicine.
Electoral Fraud, Strategic Oversight and Development

Does electoral fraud affect development? In a weak institutional environment the answer is not obvious. This paper demonstrates that electoral fraud can lower development and this effect is mediated through the partisan control of electoral institutions and the resultant ability of the incumbent to reshape electoral constituencies (strategic use of weak institutions). This paper identifies a form of electoral fraud in India in which parties register non-citizens as voters closer to the international border. Electoral constituencies are reshaped because the oversight of electoral roll cleaning is strategic; lax in a border state where the incumbent national party and the state party are allies and strict in a border state where the incumbent national party and the state party are non-allies. Finally the paper indicates poorer development outcomes in regions where non-citizens are used for electoral support.
The mechanism of nucleation for in vitro collagen fibril formation.

The formation of collagen fibrils from soluble monomers and aggregates by thermal gelation at neutral pH can be divided into two distinct stages: a nucleation phase and a growth phase. Turbidity studies of the kinetics of the precipitation reaction show that the lag-phase time or nucleation reaction time, t′l, is markedly temperature dependent while the growth reaction time is temperature independent. The activation energy of the nucleation reaction is essentially constant over the temperature range studied. In monitoring the nucleation-phase reaction by various physicochemical techniques, including viscosity, sedimentation equilibrium, and light scattering, no evidence for the formation of aggregates was observed. Enrichment of the initial collagen solution with aggregates accelerates nucleation, but de novo nuclei formation is still required even in highly aggregated collagen preparations. Removal of pepsin and pronase susceptible peptides lengthens the nucleation reaction time and increases the sensitivity of the rate of nuclei formation to changes in ionic strength. Electron microscope studies show the fibrils formed from the protease-treated collagen to be less well organized. With pepsin-treated collagen, subfibrils and obliquely striated fibrils are seen, showing that while microfibrils are formed interactions between them are modulated by the enzyme susceptible peptides in the same way that these regions modulate nuclei assembly. It appears that pepsin and pronase susceptible peptide regions of collagen play a more prominent role in the in vitro assembly of collagen molecules to form D-stagger nuclei and fibrils than do ionic interactions between helical molecular regions. A mechanism of nucleation of collagen fibrillogenesis is discussed.
Identification of Interflow Pathways and Potential Wetland Sites in the Kelly Hayfields

In support of Grand Teton National Park Service plans to restore the Kelly Hayfields to pre-homesteading conditions an inventory of soils and associated vegetation was conducted over a two year period, 2010 and 2011. Measurements from 37 soil pits and 19 associated vegetation descriptions revealed little evidence for the presence of riparian wetlands anywhere within the historic hayfields. The exception was a small area near the north eastern end of Blacktail Butte. Faint soil redoximorphic features associated with about 5% wetland indicator plant cover implies the existence of riparian wetlands at the time of homesteading. Differences in soil texture across the hayfields indicates that a mosaic of herbaceous and mountain big sagebrush/grass communities existed when agricultural conversion began. Based on these results Grand Teton National Parkâs restoration efforts should focus on re-establishment of sagebrush-grassland complexes.
Environmental Monitoring of Aircraft

Current aircraft life prediction methodologies do not take into account the effect that environmental degradation has on the structural integrity of a component. This has led to the setting of limits on the amount of damage, usually based on maintaining residual strength that can be present on a component. These arbitrary limits have caused a significant increase in the maintenance cost of aircraft, since components must undergo a repair procedure when the detected damage is above the preset limits. To better assess the state of an aircraft, sensors can be placed in areas known to be susceptible to environmental degradation, such as corrosion. These sensors can monitor the environment in the area of concern to determine if conditions are present to cause corrosion. Sensors can also be used to directly determine if corrosion damage is present on a particular component and to what level. However, procedures need to be developed to relate the parameters that are monitored by a particular sensor type to the life of the component. This may include the development of algorithms to relate the environmental parameters that favor the growth of corrosion to the corrosion damage present on the particular component. Keywords: corrosion; sensors; life assessment; maintenance
Compression of the posterior fossa venous sinuses by epidural hemorrhage simulating venous sinus thrombosis: CT and MR findings.

Background Posterior fossa dural venous sinus thrombus is a well-described complication of head trauma, especially when fracture crosses the dural sinus grooves or in association with epidural hemorrhage. We have found that post-traumatic posterior fossa epidural hematoma compressing a dural venous sinus can mimic dural venous thrombus.
Modeling and verification of hybrid systems

A hybrid system models both discrete event and continuous dynamics. We present a modeling formalism, and a verification methodology for hybrid systems. The verification methodology is based on abstracting the continuous dynamics in the hybrid system by simpler continuous dynamics. We present two methods for doing this: 1) the differential inclusion is replaced with a simpler differential inclusion; and 2) we look at the timing information that is relevant to the verification problem, and construct an abstraction of the hybrid system with a timed automaton.
Disseminated intravascular coagulation. Approach to treatment.

Disseminated intravascular coagulation (DIC) is a syndrome caused by the systemic generation of thrombin. Most cases are due to pathological activation of the intrinsic coagulation systems (e.g. in sepsis), and/or the extrinsic system (e.g. in malignancy and head trauma). Diagnosis is made by finding abnormalities in at least 3 of 4 laboratory values, namely prothrombin time, platelet count, fibrinogen and fibrinogen/fibrin degradation products. The most common clinical manifestation of DIC is bleeding, with thrombosis in less than 10% of acute cases but more frequently encountered in chronic DIC associated with malignancy. Acute DIC must first be treated by specific therapy of the underlying disease and general support measures. If serial clinical and laboratory monitoring improves, no further treatment is required. If severe or life-threatening haemorrhage occurs or a thrombotic event ensues, heparin anticoagulation followed by aggressive replacement with platelets, fresh plasma and possibly cryoprecipitate is indicated. Heparin doses should be ‘therapeutic’ (i.e. adequate to overcome the coagulant forces that may have produced a relative heparin-resistant state in the blood). Chronic DIC with haemorrhage, or more usually thrombosis, should also be treated with heparin; warfarin is ineffective. If DIC persists because, for example, a tumour does not regress, long term outpatient subcutaneous heparin therapy may be required.
P01.31. Yoga therapy associated with increased brain GABA levels and decreased depressive symptoms in subjects with major depressive disorder: a pilot study

Results MDD subjects (n=2) had PHQ-9 scores of 22 (severe depression) and 20 (moderately severe depression) at the beginning of the yoga intervention and scores of 7 (mild depression) and 4 (not depressed enough to be considered MDD) at the end of the study, respectively. The MDD subjects had mean thalamic GABA/Creatine ratios (GABA Levels) of 0.039 ± 0.004 for Scan 1 and mean GABA levels of 0.049 ± 0.010 for Scan 2 for a change of 0.014 ± 0.006. Normal subjects had mean thalamic GABA levels of 0.065 ± 0.021 for Scan 1, and 0.061 ± 0.021 for Scan 2, for a change of -0.004± 0.017.
Pitch ranking, electrode discrimination, and physiological spread-of-excitation using Cochlear's dual-electrode mode.

This study compared pitch ranking, electrode discrimination, and electrically evoked compound action potential (ECAP) spatial excitation patterns for adjacent physical electrodes (PEs) and the corresponding dual electrodes (DEs) for newer-generation Cochlear devices (Cochlear Ltd., Macquarie, New South Wales, Australia). The first goal was to determine whether pitch ranking and electrode discrimination yield similar outcomes for PEs and DEs. The second goal was to determine if the amount of spatial separation among ECAP excitation patterns (separation index, Σ) between adjacent PEs and the PE-DE pairs can predict performance on the psychophysical tasks. Using non-adaptive procedures, 13 subjects completed pitch ranking and electrode discrimination for adjacent PEs and the corresponding PE-DE pairs (DE versus each flanking PE) from the basal, middle, and apical electrode regions. Analysis of d′ scores indicated that pitch-ranking and electrode-discrimination scores were not significantly different, but rather produced similar levels of performance. As expected, accuracy was significantly better for the PE-PE comparison than either PE-DE comparison. Correlations of the psychophysical versus ECAP Σ measures were positive; however, not all test/region correlations were significant across the array. Thus, the ECAP separation index is not sensitive enough to predict performance on behavioral tasks of pitch ranking or electrode discrimination for adjacent PEs or corresponding DEs.
Mycoserology: Its Vital Role in Diagnosing Systemic Mycotic Infections

Serologic procedures are widely used in establishing the diagnosis of aspergillosis, blastomycosis, candidiasis, coccidioidomycosis, cryptococcosis, histoplasmosis, and paracoccidioidomycosis. Frequently, they are the primary basis for detecting these diseases. The serodiagnosis of aspergillosis, candidiasis, cryptococcosis, and histoplasmosis is reviewed here in detail, since these are cosmopolitan diseases. All of these mycoses have assumed greater importance in the last two decades because of their ability to affect immunocompromised persons. Some of these mycoses have restricted geographic limits, but physicians far from their endemic areas should know how to diagnose them because travel to and transient work in foreign nations have become commonplace. In some situations, however, conventional mycoserologic tests are inadequate, and newer serologic procedures and reagents are being developed and evaluated. The usefulness and pitfalls of both the conventional and the newer tests are reviewed. Because immunologic testing of cerebrospinal fluid for diagnosing mycotic infections of the central nervous system is frequently neglected, the life-saving value of such examinations is emphasized in this review.
Two-Stage Budgeting: A Difficult Problem

Utility maximization with a weakly separable utility function requires a consumer create an optimal budget for each separable subgroup. We show that computational complexity of optimal budgeting is the maximum of an exponential in the number of alternatives and a quadratic in the number of budget increments. From a budget survey of undergraduates we show that an undergraduate procedural consumer can obtain a budget estimate from the experience of previous students and can monitor the flow of funds and can make adjustments at a minuscule fraction of the calculations needed for optimal budgeting.
A Comparative Study of Photoconductivity and Luminescence

Measurements of luminescence emission and photoconductivity as a function of (1) operating temperature during excitation, (2) time during decay, and (3) temperature during thermostimulation were made for a zinc sulfide crystal. The results indicate that the processes of luminescence and photoconductivity are dissimilar. Evidence is presented for the presence of surface conductivity, especially important in measurements made with acicular crystals.
The nonholonomic and chaotic nature of a rolling isolation system

Abstract This paper presents the modeling of a rolling isolation platform used to protect objects from the hazards of horizontal shaking. The platform is built from four pairs of recessed steel bowls: four concave-up, attached to a shaking floor via a steel frame, and four concave-down, attached to the isolated object via a steel frame. Four steel ball-bearings, located between these bowls, allow the bottom- and top-frames to roll with respect to one another. In order for the four ball-bearings to remain in contact with the bowls during times of large angular rotation, the top-frame is assumed to conform to a saddle shape. The kinematics of the rolling contact impose a set of eight nonholonomic constraints to the translational and rotational dynamics of the platform center. The nonholonomic equations of state are found from the fundamental form of Lagrange's equation, which incorporates velocity constraints via Lagrange multipliers. A viscous damping model calibrated to experimental free-responses depends upon the mass of the isolated object. Precise photogrammetric measurements of a sample of these steel bowls provide the data required to calibrate the potential energy function for this system. It is shown that for the non-quadratic potential energy function of this particular system, free response trajectories are strongly sensitive to slight perturbations in initial conditions, and that the system is, in fact, chaotic. Even in the absence of any mass or stiffness eccentricity, translational and rotational motions are nonlinearly coupled through the constraint of slip-free rolling. Uni-axial models cannot be used to predict responses of these systems.
Atomic displacements in iron martensite

Abstract The effect of a carbon interstitial in iron martensite is simulated by two equal doublet forces in the [110] directions and a third doublet force in the [001] direction. The iron is treated as a finite elastically isotropic medium containing a uniform distribution of such singularities and the predicted lattice dilitations are matched to experiment to determine the strengths of the singularity. From the strengths the elastic displacement field around one carbon interstitial is calculated and compared to the displacement fields of Johnson, et al ., Krivoglaz and Tikhonova, and Fisher. There are wide divergences amongst the displacements predicted by the four theories. However, the mean-square displacements normal to the tetragonal axis are small and similar for all theories, while the elastic displacement field predicts the largest mean-square displacement in the tetragonal direction. Assuming the elastic field sets an upper limit on the magnitude of the displacements an expression for the attenuation of the Bragg reflections in martensite is given which involves three parameters. The parameters are the mean-square displacement normal to the tetragonal axis, the mean-square displacement (not including the contribution of first neighbors) in the direction of the tetragonal axis, and the first neighbor displacement. From measurement of the attenuation of the Bragg reflections in martensite the first neighbor displacement can be determined.
Instructions and reinforcement in the elimination of encopresis: A case study

Abstract A 7-yr-old boy was reported by school officials and his mother to exhibit chronic fecal soiling (encopresis). A reinforcer sampling procedure was used to expose the boy to potential reinforcers to be used in a home-based motivation system. The mother provided instructions which served to make explicit a contingency between appropriate toileting and reinforcement. Within 10 days fecal soiling was eliminated, and a token system was added to maintain this positive change. An 11-month follow-up indicated no evidence of remission or symptom substitution. Pre- and post-psychodiagnostic evaluations were at variance with the child's behavior.
The evolution and extinction of science fiction

Science fiction literature reflects our constantly evolving attitudes towards science and technological innovations, and the kinds of societal impacts believed possible. The newly popular subgenre 'steampunk' shows that these attitudes have significantly shifted. Examined from a cognitive anthropological perspective, science fiction reveals the cultural evolution of the genre as intelligently designed, and implies a cognitive mechanism of group membership reliant on implicit memory. However, such an analysis also suggests that genre science fiction as it was in the 20th century may no longer exist.
Determination of the Major Component of Some U.S.P. Adrenocortical Steroids

The determination of the total steroid content and the isolation and determination of the major steroid component in pharmaceuticals by continuous ascending chromatography and a blue tetrazolium colorimetric procedure are described. Isolation of the major steroid is achieved in 1.5 to 2 hours on 8 × 8 in. paper. The method has been applied to products containing prednisolone, hydrocortisone, prednisone, and the acetates of prednisolone, hydrocortisone, and cortisone. Accuracy within plus or minus 2 per cent was achieved.
Flexible mapping of homology onto structure with Homolmapper

Over the past decade, a number of tools have emerged for the examination of homology relationships among protein sequences in a structural context. Most recent software implementations for such analysis are tied to specific molecular viewing programs, which can be problematic for collaborations involving multiple viewing environments. Incorporation into larger packages also adds complications for users interested in adding their own scoring schemes or in analyzing proteins incorporating unusual amino acid residues such as selenocysteine. We describe homolmapper, a command-line application for mapping information from a multiple protein sequence alignment onto a protein structure for analysis in the viewing software of the user's choice. Homolmapper is small (under 250 K for the application itself) and is written in Python to ensure portability. It is released for non-commercial use under a modified University of California BSD license. Homolmapper permits facile import of additional scoring schemes and can incorporate arbitrary additional amino acids to allow handling of residues such as selenocysteine or pyrrolysine. Homolmapper also provides tools for defining and analyzing subfamilies relative to a larger alignment, for mutual information analysis, and for rapidly visualizing the locations of mutations and multi-residue motifs. Homolmapper is a useful tool for analysis of homology relationships among proteins in a structural context. There is also extensive, example-driven documentation available. More information about homolmapper is available at http://www.mcb.ucdavis.edu/faculty-labs/lagarias/homolmapper_home/homolmapper%20web%20page.htm .
Soft Budget Constraints and the Property Rights Theory of Ownership

Abstract Modeling the government make-or-buy decision, Hart and colleagues [Hart, O., Shleifer, S. and Vishny, R.W., 1997, The proper scope of government: Theory and an application to prisons, Quarterly Journal of Economics 112, 1127–1161] assume government providers are exogenously more replaceable than private providers. Instead, we posit government managers' soft incentives arise endogenously from their lack of control rights, because of rationally softer budget constraints.
Mixed diatom assemblages in glacigenic sediment from the central Ross Sea, Antarctica

We have investigated diatom assemblages and their distribution in piston and trigger cores from six sites in the central Ross Sea, including analysis of absolute abundance of diatom valves and diatom fragments, with the aim of characterising different glacigenic sediment facies and sediment packets. These data provide a new perspective on the current texturally based classification of diamicton, mud, and diatomaceous mud. All samples investigated include diatom taxa characteristic of the modern Ross Sea flora, thus all deposits evaluated are interpreted to be upper Quaternary in age. Reworked diatoms are ubiquitous, but they vary in terms of species content and concentration. Sediment units classified as diamicton are enriched in robust reworked valves of long-ranging taxa such as Paralia spp., Stephanopyxis spp., and Stellarima microtrias, but different diamicton packets can be distinguished based on variable concentrations of biostratigraphically constrained taxa including Denticulopsis spp., Thalassiosira spp., and Actinocyclus spp. Absolute abundance of diatoms and diatom fragments provide another useful criterion for distinguishing sedimentary processes. Together, these criteria permit interpretations of past glacial and glacial marine processes with greater certainty than allowed by textural analyses alone. We are able to distinguish between tills deposited beneath ice streams from those emplaced by slow-moving ice—information that is important in ice sheet reconstruction.
Impulse control disorders and attention deficit disorder in pathological gamblers.

Little systematic research has been done on psychiatric comorbidity of pathological gambling, an impulse control disorder. This report describes the occurrence of attention deficit disorder and imp...
Creep properties of a zirconium-hydrogen uranium alloy

BS>The temperature and stress dependence of the steadystate creep rate of a zirconium-hydrogen-uranium alloy (atomic ratio of 1: 1: 0.03) was determined in the tempera ture range of 500 deg to 600 deg C which includes a eutectoid transformation. The stress ( sigma ) dependence of the creep rate ( epsilon ) can be represented by an equation of the form: epsilon = k sigma /sup n/, with n = 4.1 below the transformation temperature and n = 4.7 to 4.9 above the transformation temperature. An activation energy of 80,000 cal/g atom was observed below the transformation temperature, whereas values of 65,000 to 73,000 cal/g atom were observed above the transformation temperature. (auth)
Self-consistent rate theory of submonolayer homoepitaxy with attachment/detachment kinetics

The reversible nucleation and growth of two-dimensional islands during the submonolayer stage of epitaxial growth is studied with self-consistent rate equations and kinetic Monte Carlo simulations. In contrast to most previous work, we take account of the effects of both a finite energy barrier to the detachment of atoms from islands and a finite barrier to the incorporation of adatoms into islands. A correct boundary condition for the diffusion field at island edges is derived that takes account of these processes. For small detachment rates, quantitative agreement is obtained between the solutions to the rate theory and the simulations for the average monomer and island densities as a function of coverage. {copyright} {ital 1997} {ital The American Physical Society}
Does timing matter? How priority effects influence the outcome of parasite interactions within hosts

In nature, hosts are exposed to an assemblage of parasite species that collectively form a complex community within the host. To date, however, our understanding of how within-host–parasite communities assemble and interact remains limited. Using a larval amphibian host (Pacific chorus frog, Pseudacris regilla) and two common trematode parasites (Ribeiroia ondatrae and Echinostoma trivolvis), we experimentally examined how the sequence of host exposure influenced parasite interactions within hosts. While there was no evidence that the parasites interacted when hosts were exposed to both parasites simultaneously, we detected evidence of both intraspecific and interspecific competition when exposures were temporally staggered. However, the strength and outcome of these priority effects depended on the sequence of addition, even after accounting for the fact that parasites added early in host development were more likely to encyst compared to parasites added later. Ribeiroia infection success was reduced by 14 % when Echinostoma was added prior to Ribeiroia, whereas no such effect was noted for Echinostoma when Ribeiroia was added first. Using a novel fluorescent-labeling technique that allowed us to track Ribeiroia infections from different exposure events, we also discovered that, similar to the interspecific interactions, early encysting parasites reduced the encystment success of later arriving parasites by 41 %, which could be mediated by host immune responses and/or competition for space. These results suggest that parasite identity interacts with host immune responses to mediate parasite interactions within the host, such that priority effects may play an important role in structuring parasite communities within hosts. This knowledge can be used to assess host–parasite interactions within natural communities in which environmental conditions can lead to heterogeneity in the timing and composition of host exposure to parasites.
Pulmonary toxicity, hepatic, and extrahepatic metabolism of 2-methylnaphthalene in mice.

Abstract Male mice ( C57BL 6J ) were injected once ip with 0.1, 1, 100, 200, 400, 600, 800, or 1000 mg/kg of 2-methylnaphthalene dissolved in corn oil. After 24 hr, the animals were killed and the lungs, livers, and kidneys were prepared for light microscopy. In addition, some lungs were subjected to scanning and transmission electron microscopy. A dose of 200 mg/kg produced a bronchiolar necrosis which affected the nonciliated bronchiolar (Clara) cell; the parenchymal cells remained unaffected. At higher doses of 2-methylnaphthalene (800 mg/kg), in addition to the damaged Clara cell, severe damage to the upper respiratory tract was noted. No liver or kidney pathology was detected by light microscopy in animals treated with the highest dose. No cellular damage was noted in any organ at doses less than 200 mg/kg. Forty-eight hours after a dose of 200–1000 mg/kg of 2-methylnaphthalene, less pulmonary damage was detected by light microscopy. The metabolism of 2-methylnaphthalene was investigated in hepatic, pulmonary, and renal microsomes from C57BL 6J mice. Lung and liver microsomes produced three isomeric dihydrodiols of 2-methylnaphthalene as well as other monohydroxylated metabolites. Only trace amounts of these metabolites were produced by the kidney.
Ecumenicity or Orthodoxy: The Dilemma of The Protestants in the Lands of the Austrian Habsburgs

The call for the reform of the life and teachings of the church which emanated from Wittenberg early in the sixteenth century elicited an almost immediate response in southeast central Europe. In the lands which came under the rule of Ferdinand I after the disastrous battle at Mohacs, reformation doctrines and practices spread quickly. By the middle of the sixteenth century the majority of the population in the lands ruled by the Austrian Habsburgs adhered to one of the several evangelical reform movements. Hussite, Lutheran, Helvetic, Anabaptist and Anti-Trinitarian theologies all found supporters in the region.
An association between periodontal disease and peripheral vascular disease.

BACKGROUND: Periodontal disease has been shown to be associated with increased risk of coronary heart disease. Because coronary heart disease and peripheral vascular disease (PVD) have similar pathophysiologies, we hypothesized that periodontal disease might be a risk factor for PVD. METHODS: Using the combined data from the Normative Aging Study and Dental Longitudinal Study of the US Department of Veterans Affairs, we examined the relationship between PVD and periodontal disease. Multivariate logistic regression analysis was used. RESULTS: Over the 25 to 30 years of follow-up, 80 of these initially healthy subjects developed PVD. Compared with controls (n = 1,030), subjects with clinically significant periodontal disease at baseline had a 2.27 increment in the risk of developing PVD (95% confidence interval 1.32 to 3.9, P value = 0.003). CONCLUSIONS: Periodontal disease emerged as a significant independent risk factor for PVD in a multivariate analysis that adjusted for other established risk factors.
Human Carbonic Anhydrase III: Structural and Kinetic Study of Catalysis and Proton Transfer

The residue phenylalanine 198 (Phe 198) is a prominent cause of the lower activity of human carbonic anhydrase III (HCA III) compared with HCA II and other isozymes which have leucine at this site. We report the crystal structures of HCA III and the site-directed mutant F198L HCA III, both at 2.1 A resolution, and the enhancement of catalytic activity by exogenous proton donors containing imidazole rings. Both enzymes had a hexahistidine extension at the carboxy-terminal end, used to aid in purification, that was ordered in the crystal structures bound in the active site cavity of an adjacent symmetry-related enzyme. This observation allowed us to comment on a number of possible binding sites for imidazole and derivatives as exogenous proton donors/acceptors in catalysis by HCA III. Kinetic and structural evidence indicates that the phenyl side chain of Phe 198 in HCA III, about 5 A from the zinc, is a steric constriction in the active site, may cause altered interactions at the zinc-bound solvent, and is a binding site for the activation of catalysis by histidylhistidine. This suggests that sites of activation of the proton-transfer pathway in carbonic anhydrase are closer to the zinc than considered in previous studies.
Leveraging Memristive Systems in the Construction of Digital Logic Circuits

The recent emergence of the memristor has led to a great deal of research into the potential uses of the devices. Specifically, the innate reconfigurability of memristors can be exploited for applications ranging from multilevel memory, programmable logic, and neuromorphic computing, to name a few. In this work, memristors are explored for their potential use in dense programmable logic circuits. While much of the work is focused on Boolean logic, nontraditional styles including threshold logic and neuromorhpic computing are also considered. In addition to an analysis of the circuits themselves, computer-aided design (CAD) flows are presented which have been used to map digital logic functionality to dense complementary metal-oxide-semiconductor (CMOS)-memristive logic arrays. As exemplified through the circuits described here memristor-based digital logic holds great potential for high-density and energy-efficient computing.
Tree-structured extreme value model regression

This paper gives a method for fitting piecewise Weibull regression models to censored survival data. Recursive stratification is performed using statistical tests for variances and residual analysis. The average squared error of the residuals is used as a splitting criterion in cross-validation. The bootstrap resampling is used to keep the probability of a type I error of the method (the error of finding two or more strata when there is one). Real and simulated data are used for illustration.
Glucose and lysogenesis in Bacillus megatherium.

CELLS of Bacillus megatherium strain 1.0 can carry on metabolic activity, including multiplication, simultaneously with virus formation, for an infinite time; this balance between the cells and their virus is called lysogenesis. Evidence that lysogenic Bac. megatherium strain 1.0 can return to the normal uninfected state on a glucose nutrient medium was presented by Ehrlich and Watson1. Further study of this phenomenon showed that other sources of carbon, such as fructose, maltose, sucrose, glycerol, pyruvate and succinate in the basal medium all cause recovery from the lysogenic state. In postulating an explanation for this behaviour, it was thought that the virus and the source of carbon might compete for organic phosphate and that the virus was the weaker competitor. The work of Kozloff and Putnam suggested such a hypothesis2. However, initial studies showed that this hypothesis could not explain the effect of glucose on lysogenic Bac. megatherium strain 1.0.
Calibration of the magnetic compass of a migratory bird by celestial rotation

MIGRATORY birds use a variety of environmental stimuli in orientation. Species that migrate primarily at night can use compasses based on the geomagnetic field, stars, the Sun and patterns of skylight polarization1–4. These compass mechanisms can interact both when migratory birds make day-to-day orientation decisions5 and during their ontogeny in young birds6,7. All of the known compasses used by migratory birds seem to be modifiable by experience during early development. For example, a functional magnetic compass develops in birds that have never seen the sky8–11. But the preferred direction of orientation by the magnetic compass may be modified during the first three months of life by exposing naive birds to the sky under conditions in which magnetic directions differ substantially from compass directions indicated by the Sun and stars (true or geographic directions)6,9,10. For hand-raised Savannah sparrows (Passerculus sandwichensis), experience with either the clear daytime or night sky is sufficient to effect this calibration of the magnetic compass11. We therefore proposed that celestial rotation, which provides a source of geographic directions both day and night, is the calibrating reference. Here we report that the rotation of an artificial pattern of 'stars' calibrates the preferred direction of magnetic orientation of young Savannah sparrows.