cssi/SciSciGPT-SciSciNet huggingface dataset:
Automated quantitative assessment of wall motion in patients with poor acoustic windows

Abstract Background No technique exists for objective evaluation of left ventricular wall motion in contrast-enhanced images. We tested a new technique for quantification of regional fractional area change using contrast-enhanced power modulation imaging with color kinesis. Methods The feasibility of this technique for detecting acute ischemia was first tested in 11 pigs. Next, the accuracy for detecting resting wall-motion abnormalities was determined in 52 patients requiring contrast and compared with conventional interpretation of 2-dimensional images by inexperienced readers. Expert interpretation of 2-dimensional images served as the gold standard. Results In pigs, coronary occlusion resulted in reversible hypokinesis and reduced regional fractional area change. In patients with poor acoustic windows, this technique's accuracy for quantitative detection of resting wall-motion abnormalities was 86% compared with 81% for conventional interpretation by inexperienced readers ( P Conclusions Regional wall motion can be accurately assessed using color-encoded power modulation imaging for patients requiring contrast. This technique may prove a useful diagnostic aid to echocardiographers of varying levels of experience.
Workforce Projections for Emergency Medicine: How Many Emergency Physicians Does the United States Need?

Objective: To mathematically model the supply of and demand for emergency physicians (EPs) under different workforce conditions. Methods: A computer spreadsheet model was used to project annual EP workforce supply and demand through the year 2035. The mathematical equations used were: supply = number of EPs at the beginning of the year plus annual residency graduates minus annual attrition; demand = 5 full-time equivalent positions/ED X the number of hospital EDs. The demand was empirically varied to account for ED census variation, administrative and teaching responsibilities, and the availability of physician extenders. A variety of possible scenarios were tested. These projections make the assumption that emergency medicine (EM) residency graduates will preferentially fill clinical positions currently filled by EPs without EM board certification. Results: Under most of the scenarios tested, there will be a large deficit of EM board-certified EPs well into the next century. Even in scenarios involving a decreasing “demand” for EPs (e.g., in the setting of hospital closures or the training of physician extenders), a significant deficit will remain for at least several decades. Conclusions: The number of EM residency positions should not be decreased during any restructuring of the U.S. health care system. EM is likely to remain a specialty in which the supply of board-certified EPs will not meet the demand, even at present levels of EM residency output, for the next several decades.
Simultaneous vs. sequential analysis for population PK/PD data I: best-case performance.

Dose [-concentration]-effect relationships can be obtained by fitting a predictive pharmacokinetic (PK)-pharmacodynamic (PD) model to both concentration and effect observations. Either a model can be fit simultaneously to all the data (“simultaneous” method), or first a model can be fit to the PK data and then a model can be fit to the PD data, conditioning in some way on the PK data or on the estimates of the PK parameters (“sequential” method). Using simulated data, we compare the performance of the simultaneous method with that of three sequential method variants with respect to computation time, estimation precision, and inference. Using NONMEM, under various study designs, observations of one type of PK and one type of PD response from different numbers of individuals were simulated according to a one-compartment PK model and direct Emax PD model, with parameters drawn from an appropriate population distribution. The same PK and PD models were fit to these observations using simultaneous and sequential methods. Performance measures include computation time, fraction of cases for which estimates are successfully obtained, precision of PD parameter estimates, precision of PD parameter standard error estimates, and type-I error rates of a likelihood ratio test. With the sequential method, computation time is less, and estimates are more likely to be obtained. Using the First Order Conditional Estimation (FOCE) method, a sequential approach that conditions on both population PK parameter estimates and PK data, estimates PD parameters and their standard errors about as well as the “gold standard” simultaneous method, and saves about 40% computation time. Type-I error rates of likelihood ratio test for both simultaneous and sequential approaches are close to the nominal rates.
Synthesis, structure and DFT study of a pyrazolate stabilized mononuclear Rh(II) complex

Reaction of 3,5-(CF3)2PzLi with anhydrous RhCl3 in THF gives [Li(THF)]2Rh(μ-3,5-(CF3)2Pz)4 (1) as a rare example of a mononuclear, paramagnetic Rh(II) complex (Pz = pyrazolate).
p53 mutations, O6-alkylguanine DNA alkyltransferase activity, and sensitivity to procarbazine in human brain tumors.

Background. In human brain tumors, sensitivity to procarbazine as measured by sensitivity in a xenograft tumor model correlated inversely with amounts of the DNA repair enzyme O6-alkylguanine DNA alkyltransferase(AT). Methods. To test the hypothesis that mutations of the p53 tumor suppressor gene in human tumors also can correlate with the response to chemotherapy, p53 mutations were identified in primary human malignant brain tumors and cell lines in which AT activity and procarbazine sensitivity in a xenograft model was ascertained. Results. Mutations were identified in 7 of 21 (33%) specimens tested. Specimens containing p53 mutations tended to exhibit an increased growth delay in procarbazine-treated xenografts and lower amounts of AT. Conclusions. p53 mutations in brain tumors may contribute to procarbazine sensitivity by failing to induce arrest at the G1/S cell-cycle checkpoint, thereby preventing the repair of procarbazine-induced genetic alterations. Cancer 1995;75:1339-42.
The effect of added light pulses on overwintering and diapause, under natural light and temperature conditions, of four species of Lepidoptera.

Pupae of the tobacco budworm, Heliothis virescens (F.), diapausing and developing larvae of the codling moth, Laspeyresia pomonella (L.), diapausing larvae of the pink bollworm, Pectinophora gossypiella (Saunders), and diapausing pupae of an oak silk-worm, Antheraea pernyi Guerin-Meneville, were exposed in cubicles to 1-h light breaks interjected into the scotophase following the photophase during fall, winter, spring, and early summer. The emergence of adult oak silkworms in the spring and early summer was accelerated compared with the controls by a 1-h light break interjected any time during the night. Termination of diapause in pink bollworm and codling moth larvae was delayed by a 1-h light break interjected into the dark period 20 h after dawn. Diapausing tobacco budworm pupae did not survive the winter but development to pharate adults occurred when 1-h light breaks were interjected 15, 16, 20, or 22 h after dawn.
Optimal traversal planning in road networks with navigational constraints

A frequent query in geospatial planning and decision making domains (e.g., emergency response, data acquisition, street cleaning), is to find an optimal traversal plan (OTP) that traverses an entire area (e.g., a city) by navigating through all its streets. The optimality is defined in terms of the time it takes to complete the traversal. This time depends on the number of times each street segment is traversed as well as the navigation time such as the time spent on changing direction at each intersection.While the problem roots in the classic problems of graph theory, real-world geospatial constraints of road network introduce new application-specific challenges. In this paper, we propose two algorithms to find OTP of a directed road network. Our greedy algorithm employs a classic graph traversal algorithm. During the traversal, it utilizes a set of heuristics at each intersection to minimize the total travel time. Our near-optimal algorithm, however, reduces an OTP problem to an Asymmetric Traveling Salesman Problem (ATSP) by extracting the dual graph of the original network in which each edge is represented by a graph node. Using an approximate solution for ATSP, our algorithm finds a near optimal answer. Our experiments using real-world road networks verify that our near-optimal algorithm outperforms the greedy algorithm in terms of the overall cost of its generated traversal by a factor of two, while its complexity is tolerable in real-world cases.
Stress-related activation of Epstein-Barr virus

Herpesviruses characteristically persist in a latent state in the body over the lifetime of an individual. Under certain conditions, any one of the herpesviruses can be reactivated. The mechanisms underlying the establishment of latent virus infection or viral reactivation are not well understood; however, it is known that the cellular immune response plays a very important role in the maintenance of latency and in virus reactivation. One of the factors thought to be associated with the reactivation of latent herpes-viruses is psychological stress. Using an examination stress model with medical student subjects, we previously demonstrated the reactivation of latent Epstein-Barr virus (EBV), as measured by increases in antibody titers. In this follow-up study using the same group of medical students, we found evidence for incomplete reactivation of latent EBV, with only selective expression of the latent virus genome.
Plastic deformation and fracture of binary TiAl-base alloys

The mechanical behavior of binary TiAl alloys containing 46 to 60 at. pct Al has been studied in bulk materials preparedvia rapid solidification processing. Bending and tensile tests were carried out at room temperature as a function of Al concentration. A few alloys were also tested from liquid nitrogen temperature to ∼ 1000°C. Deformation substructures were studied by analytical transmission electron microscopy and fracture modes by scanning electron microscopy (SEM). It was found that both microstructure and composition strongly affect the mechanical behavior of TiAl-base alloys. A duplex structure, which contains both primary y grains and transformedγ/α 2 lamellar grains, is more deformable than a single-phase or a fully transformed structure. The highest plasticities are observed in duplex alloys containing 48–50 at. pct Al after heat treatment in the center of theγ + α phase field. The deformation of these duplex alloys is facilitated by 1/2[110] slip and {111} twinning, but very limited superdislocation slip occurs. The twin deformation is suggested to result from a lowered stacking fault energy due to oxygen depletion or an intrinsic change in chemical bonding. Other factors, such as grain size and grain boundary chemistry and structure, are important from a fracture point of view. The results on the deformation and fracture modes as a function of test temperature are also discussed.
Time-Variable Refraction of the Internal Tide at the Hawaiian Ridge

AbstractThe interaction of the dominant semidiurnal M2 internal tide with the large-scale subtidal flow is examined in an ocean model by propagating the tide through an ensemble of background fields in a domain centered on the Hawaiian Ridge. The background fields are taken from the Simple Ocean Data Assimilation (SODA) ocean analysis, at 2-month intervals from 1992 through 2001. Tides are computed with the Primitive Equation Z-coordinate Harmonic Analysis of Tides (PEZ-HAT) model by 14-day integrations using SODA initial conditions and M2 tidal forcing. Variability of the tide is found to occur primarily as the result of propagation through the nonstationary background fields, rather than via generation site variability. Generation of incoherent tidal variability is mapped and shown to occur mostly in association with waves generated at French Frigate Shoals scattering near the Musicians Seamounts to the north of the ridge. The phase-coherent internal tide loses energy at a domain-average rate of 2 mW m−...
Growth of Perturbations in Gravitational Collapse and Accretion

When a self-gravitating spherical gas cloud collapses or accretes onto a central mass, the inner region of the cloud develops a density profile ρ ∝ r^(-3/2) and the velocity approaches free fall. We show that in this region nonspherical perturbations grow with decreasing radius. In the linear regime, the tangential velocity perturbation increases as r^(-1), while the Lagrangian density perturbation, Δρ/ρ, grows as r^(-1/2). Faster growth occurs if the central collapsed object maintains a finite multiple moment, in which case Δρ/ρ increases as r^(-l), where l specifies the angular degree of the perturbation. These scaling relations are different from those obtained for the collapse of a homogeneous cloud. Our numerical calculations indicate that nonspherical perturbations are damped in the subsonic region and that they grow and approach the asymptotic scalings in the supersonic region. The implications of our results to asymmetric supernova collapse and to black hole accretion are briefly discussed.
Semiclassical electron models: Casimir self-stress in dielectric and conducting balls

Abstract The Casimir self-stress, due to fluctuations of the electromagnetic field, for a solid dielectric ball is calculated using a formalism previously employed for the reevaluation of the repulsive Casimir stress on a conducting spherical shell. Even after volume energy subtractions are performed, the results are cutoff dependent. It is argued that the cutoff-dependent term is spurious, perhaps being a modification to the phenomenological description of the medium, and so should be cancelled by a contact term. If so, we are left with an attractive Casimir stress, which could play the role of the Poincare stress in classical electron theory. The limit ϵ → ∞, a perfectly conducting ball, is more convergent and gives a parameter-free value for the fine-structure constant, α ⋍ 1 4π .
Jim Gray - A Talk with THE SQL Guru and Architect

Jim Gray is a distinguished engineer in Microsoft's Scalable Servers Research Group and manager of our Bay Area Research Center. That doesn't even start to do justice to the role Jim has played in the development of databases. You might know him as the guy behind Terra Service or Sky Server. We sat down with Jim for a couple of hours. Here's the first part. We talk about everything about new database architectures to new trends in computing to his role in Terra Service. http://channel9.msdn.com/Blogs/TheChannel9Team/Jim-Gray-A-talk-with-THE-SQL-Guru-and-Architect
Observation of hyperfine quantum beats in two-color laser-induced grating spectroscopy of nitric oxide

Abstract Two-color laser-induced grating spectroscopy of NO via the A 2 Σ + , v ′=0 state has been used to study the time evolution of population gratings produced in a supersonic molecular beam. For a specific polarization configuration of the input laser beams, quantum beats due to the hyperfine structure of the A 2 Σ + , v ′=0 state have been observed by varying the delay between the grating-forming laser pulses and the grating-probing laser pulse. This form of quantum beat spectroscopy has the advantages of background-free detection, two-color state selectivity, a quadratic dependence on the level population, and a beat signal independent of the decay mode.
Coronal Heating by the Resonant Absorption of Alfven Waves: Importance of the Global Mode and Scaling Laws

Numerical simulations of the MHD equations for a fully compressible, low-beta, resistive plasma are used to study the resonance absorption process for the heating of coronal active region loops. Comparisons with more approximate analytic models show that the major predictions of the analytic theories are, to a large extent, confirmed by the numerical computations. The simulations demonstrate that the dissipation occurs primarily in a thin resonance layer. Some of the analytically predicted features verified by the simulations are (a) the position of the resonance layer within the initial inhomogeneity; (b) the importance of the global mode for a large range of loop densities; (c) the dependence of the resonance layer thickness and the steady-state heating rate on the dissipation coefficient; and (d) the time required for the resonance layer to form. In contrast with some previous analytic and simulation results, the time for the loop to reach a steady state is found to be the phase-mixing time rather than a dissipation time. This disagreement is shown to result from neglect of the existence of the global mode in some of the earlier analyses. The resonant absorption process is also shown to behave similar to a classical driven harmonic oscillator.
Dynamics of Palmitic Acid Complexed with Rat Intestinal Fatty Acid Binding Protein

Dynamics of palmitic acid (PA), isotopically enriched with 13C at the second, seventh, or terminal methyl position, were investigated by 13C NMR. Relaxation measurements were made on PA bound to re...
Family Financial Stress, Parental Support, and Young Adolescents' Academic Achievement and Depressive Symptoms

This study investigated the relationship among family financial stress, parents' emotional-affective support for their children, and academic achievement and depressive symptoms in 105 sixth-, seventh-, and eighth-graders from farm and nonfarm families. ANOVA results indicated that parents from farm families reported higher levels of family financial stress and of depression than parents from nonfarm families. While multiple regression analyses did not reveal a relationship between family financial stress and maternal or paternal levels of emotional-affective support for their adolescent children, or between family financial stress and the adolescents' academic performance, they did show that family financial stress as reported by parents was strongly related to adolescents' reports of depressive symptoms.
Medication Nebulizer Performance: Effects Of Diluent Volume, Nebulizer Flow, and Nebulizer Brand

Background Medication nebulizers are commonly used to delivery aerosolized medications to patients with respiratory disease. We evaluated output and respirable aerosol available to the patient (inhaled mass) for 17 medication nebulizers using a spontaneous breathing lung model. Methods Three nebulizer fill volumes (3, 4, and 5 mL containing 2.5 mg of albuterol) and 3 oxygen flows (6, 8, and 10 L/min) were evaluated using the 17 nebulizers. A cotton plug at the nebulizer mouthpiece was used to trap aerosol during simulated spontaneous breathing. Following each trial, the amount of albuterol remaining in the nebulizer and the amount deposited in the cotton plug were determined spectrophotometrically. Aerosol particle size was determined using an 11-stage cascade impactor. Results Increasing fill volume decreased the amount of albuterol trapped in the dead volume (p Conclusions The performance of medication nebulizers is affected by fill volume, flow, and nebulizer brand. When they are used for research applications, the nebulizer characteristics must be evaluated and reported for the conditions used in the investigation.
Cell pattern formation controlled by microscale interfaces

Regenerative medicine aims at cell-based therapy to rebuild the non-regenerative tissue. To mimic the tissue development, supportive scaffolds have been intensively studied to allow cell attachment, migration, and to control delivery of essential factors. However, tissue is characterized by self-organization, which can limit the attempts to directly control the tissue development. Previously we applied local substrate discontinuity to cultured vascular stem cells (VSCs), which spontaneously aggregate into periodic multicellular patterns resembling normal tissue architectures [1], and showed that the substrate interface can led to change of pattern morphology via their inherent self-organization [2]. In the present study, we study the effects of 1) geometrical interface (micromachined surface geometrical step), 2) chemical interface (substrate discontinuity), and 3) cellular interface (stepwise cell distributions) to the development of global pattern formations. The findings suggest that cells sense the local stimuli and unfold it into multicellular structures, providing a new way for cell-based engineering of tissue architecture.
Clinical tests for subscapularis integrity: A “hole” in one?

Abstract Thorough physical examination is especially important in the diagnosis of subscapularis tears; given that many tears are missed on MRI evaluation. The belly-press test may be the best test in cases where internal rotation is limited, while the belly-off sign is very sensitive for partial subscapularis tears as long as the external rotators are intact. The internal rotation lag sign, followed by the lift-off test, is the most sensitive test for predicting complete deficiency of the subscapularis when range of motion is not limited.
Research on Teacher Quality: Improving Reading and Writing Instruction

Across the United States, a growing consensus of key elements in a successful reading program is being reached. In this consensus, the focus is on the teacher. Without a doubt, the quality of the i...
Design and performance of a time-of-flight system for particle identification at the Fermilab collider

Abstract The design and performance of a TOF system used in a Fermilab collider experiment is evaluated in terms of time, mass, and spatial resolution. The system is designed to survive in a high rate and high background environment. The overall time resolution of the TOF system is measured to be σ = 110 ps.
Optimal appropriateness measurement

The test-taking behavior of some examinees may be so idiosyncratic that their test scores may not be comparable to the scores of more typical examinees. Appropriateness measurement attempts to use answer patterns to recognize atypical examinees. In this report appropriateness measurement procedures are viewed as statistical tests for choosing between a null hypothesis of normal test-taking behavior and an alternative hypothesis of atypical test-taking behavior. Most powerful tests for inappropriateness are described together with methods for computing their power. A recursion greatly simplifying the calculation of optimal test statistics is described and illustrated.
Angle-resolved photoemission from atomic-layer-resolved quantum well states in Ag/Fe(100)

Abstract Angle-resolved photoemission from thin films of Ag on Fe(100) grown with a low temperature deposition and annealing technique shows clear quantum well peaks for coverages up to 12 monolayers. Pairs of peaks are sometimes observed in the spectra; atomic layer resolution is demonstrated and used to explain these pairs without invoking spin splitting. The peaks are observed only within an energy window defined by the minority spin hybridization gap within the Fe substrate. Large intensity variations of the quantum well states with photon energy are observed.
Secondary renal neoplasms

The widespread use of computed tomography (CT) and sonography has led to the increased detection of renal masses, many of which are small and asymptomatic. In general, solid renal masses are treated as renal adenocarcinomas until proven otherwise [1]. This treatment often results in nephrectomy, some of which are unnecessary. A renal metastasis can be suspected when there is an underlying primary tumor. Although the imaging characteristics are not pathognomonic, the imaging features in the appropriate clinical setting may lead to the correct diagnosis and the most appropriate management.
Spin-up and wrapping of cryogenic helium bubble around dewar well from rest in microgravity

Abstract Time dependent animation of spherically shaped bubble sitting at one-side of the dewar container, which is spin-up from rest to certain rotating speed of interests, has been investigated. Time dependent deformation of bubble with or without a completion of wrapping around the inner well of the rotating dewar, are numerically studied and simulated. Some similarity parameters are considered for a completion of bubble wrapping around the dewar well. Illustrative examples show that the degree of the completion of bubble wrapping around the dewar well increases with increasing container rotating speed and Weber number.
Fusarium oxysporum f. sp. palmarum, a Novel Forma Specialis Causing a Lethal Disease of Syagrus romanzoffiana and Washingtonia robusta in Florida

A new disease of Syagrus romanzoffiana (queen palm) and Washingtonia robusta (Mexican fan palm) has spread across the southern half of Florida during the past 5 years. The initial foliar symptom is a one-sided chlorosis or necrosis of older leaf blades, with a distinct reddish-brown stripe along the petiole and rachis and an associated discoloration of internal tissue. Within 2 to 3 months after onset of symptoms, the entire canopy becomes desiccated and necrotic but the leaves do not droop or hang down around the trunk. Based on pathogenicity and morphological and molecular characterization, the etiological agent has been identified as a new forma specialis of Fusarium oxysporum, designated f. sp. palmarum. Sequence analysis of a portion of the translation elongation factor 1-α gene (EF-1α) separated 27 representative isolates into two EF-1α groups, which differed by two transition mutations. Members of both EF-1α groups are pathogenic on both species of palm. A phylogenetic analysis inferred from partial EF-1α sequences from a genetically diverse set of F. oxysporum isolates, including three other formae speciales pathogenic on palm (i.e., f. sp. albedinis, f. sp. canariensis, and f. sp. elaeidis), suggested that f. sp. palmarum and f. sp. albedinis may be more closely related to one another than either is to the two other palm pathogens.
A three-fold introduction to computer science

We have developed a new introduction to the computer science major, consisting of two courses, called Science of Computing 1 and Science of Computing 2. This sequence emphasizes balanced development of basic abilities in all three of computer science's fundamental methods of inquiry (design, theory, and empirical analysis), as opposed to the more traditional emphasis on programming and data structures. Science of Computing 1 introduces students to all three methods of inquiry, in the context of recursive algorithms and their mathematical and experimental analysis. Science of Computing 2 extends, and provides extensive practice in, all three methods. Both courses use a strongly hands-on approach to demonstrate the importance of, and interactions between, the three methods of inquiry. Preliminary results indicate that these courses successfully teach basic design, theory, and empirical analysis, and encourage students to continue studying computer science at a rate as high as or higher than that of traditional introductory courses.
The application of sequential sampling to simulation: an example inventory model

Four different sequential sampling procedures are applied to the analysis of data generated by a computer simulation experiment with a multi-item inventory model. For each procedure the cost of computer time required to achieve given levels of statistical precision is calculated. Also the cost of computer time using comparable fixed sample size methods is calculated. The computer costs of fixed sample size procedures versus sequential sampling procedures are compared.
Raman spectroscopy of molecules adsorbed on surfaces: progress, issues and prospects

Abstract Over the past decade, Raman Spectroscopy has become a powerful probe of structures and reactions of molecules adsorbed on solid surfaces. Key developments in this field are reviewed; a discussion of outstanding issues, which include selection rules and intensities, is presented and prospects for future progress are outlined.
1163 SEQUENTIAL PULMONARY FUNCTION STUDIES IN VERY LOW BIRTH WEIGHT INFANTS (VLBW) DURING THE FIRST WEEK OF LIFE

1163 SEQUENTIAL PULMONARY FUNCTION STUDIES IN VERY LOW BIRTH WEIGHT INFANTS (VLBW) DURING THE FIRST WEEK OF LIFE
Epifluorescence microscopy with a pulsed nitrogen tunable dye laser source.

SUMMARY This paper describes an epifluorescence system that uses a pulsed laser source as an excitation source for quantitative fluorescence measurements. A 1 μm diameter portion of the sample can be illuminated with high intensity, short light pulses and the fluorescence can be measured with a fast detection system. Selective excitation is possible at 337 nm and from 357 to 710 nm by using different dyes in the laser system. The spectral bandwidth is 0·1–3 nm. Several advantages over the commonly used systems with continuum spectral sources are indicated, especially when measured intensities are low, as in the case of intrinsic fluorescence of the sample, and where reflection of unwanted excitation light may cause appreciable errors when using conventional light sources.
Manipulating light with photonic crystals

We review some of the recent advances in the theory of photonic crystals, drawing examples from our own work in magneto-optical and dynamic photonic crystals. The combination of theory and simulations shows that these crystal structures exhibit rich optical physics effects, and can provide new ways to accomplish sophisticated optical information processing tasks.
A first-year medical school pilot program for early clinical exposure.

Abstract A weekly out‐patient elective in a medical oncology clinic was established for first‐ and some second‐year medical students. Interviews were carried out immediately after the elective experience and two years later to evaluate the degree of success in achieving specific goals in this elective. Such clinical experience appeared to introduce the medical students to some of the major medical and psychosocial issues involved in the clinical care of patients, to be highly motivating for the students with regard to their standard concurrent basic science curriculum, and to relieve the impatience that first‐year medical students have for clinical exposure. The usefulness of the elective, as perceived by the participating students, appeared to increase from the first to the second interview, that is as the students entered the clinical teaching program. The clinical setting was perceived by the students as more useful than either their increased understanding of medicine or observation of physicians as r...
Physical investigations of the hemocyanin of the chiton, Cryptochiton stelleri (Middendorff).

Abstract 1. 1. The hemocyanin of the giant Pacific chiton, Cryptochiton stelleri has a molecular weight of 4.2 ± 0.3 × 10 6 , determined by light-scattering, and a sedimentation coefficient of 60S. 2. 2. The fully dissociated subunits in nondenaturing solvents, at pH 10.6, 1 × 10 −2 M EDTA and in 8.0 M urea, pH 7.4 have molecular weights of 4.10 × 10 5 and 4.35 × 10 5 , close to one-tenth of the molecular mass of the parent hemocyanin decamers. 3. 3. In the pH region from about 3.5 to 11 the molecular weight (M w ), determined at constant protein concentration of 0.10 g 1 −1 exhibits a bell-shaped molecular weight profile centering about the physiological pH of the hemolymph of 7.2. The pH-M w profile is best accounted for in terms of a three state, decamer-dimer-monomer dissociation scheme. 4. 4. Analysis of the Mg 2+ and Ca 2+ effects on the molecular weight transitions suggest stabilization of the hemocyanin decamers through one bound divalent ion per hemocyanin monomer or dimer. 5. 5. Urea, GdmCl, and the higher members of the chaotropic salt series are effective dissociating agents for Cryptochiton stelleri hemocyanin. The dissociation profile obtained with urea at pH 8.5, 0.01 M Mg 2+ , 0.01 M Ca 2+ has been analyzed in terms of both the two- and three-species schemes of subunit-dissociation. 6. 6. Hydrophobic stabilization of the subunit contacts is suggested by the large number of apparent amino acid groups ( N app ), of the order of 30 between dimers stabilizing the decamers, and 120 apparent amino acid groups between each monomer forming the constituent dimers.
Synthesis of RNA oligomers on heterogeneous templates

The concept of an RNA world in the chemical origin of life is appealing, as nucleic acids are capable of both information storage and acting as templates that catalyse the synthesis of complementary molecules. Template-directed synthesis has been demonstrated for homogeneous oligonucleotides that, like natural nucleic acids, have 3',5' linkages between the nucleotide monomers. But it seems likely that prebiotic routes to RNA-like molecules would have produced heterogeneous molecules with various kinds of phosphodiester linkages and both linear and cyclic nucleotide chains. Here we show that such heterogeneity need be no obstacle to the templating of complementary molecules. Specifically, we show that heterogeneous oligocytidylates, formed by the montmorillonite clay-catalysed condensation of actuated monomers, can serve as templates for the synthesis of oligoguanylates. Furthermore, we show that oligocytidylates that are exclusively 2',5'-linked can also direct synthesis of oligoguanylates. Such heterogeneous templating reactions could have increased the diversity of the pool of protonucleic acids from which life ultimately emerged.
Urgent Surgical Airway Intervention: A 3 Year County Hospital Experience

Objectives: To review the indications, complications, and outcomes of patients undergoing urgent surgical airway intervention. Methods: The inpatient and outpatient charts of patients who underwent awake tracheostomy or were converted from cricothyrostomy to tracheostomy at our institutional-affiliated County Hospital over a 3 year period were reviewed. Results: Ninety patients underwent awake tracheotomy, and seven were converted from cricothyrostomy to tracheostomy. Indications for awake tracheotomy included impending airway obstruction from malignancy of the aerodigestive tract or that causing extrinsic compression of the airway in 72 (80%) patients, neck abscess in 4 (4.4%), subglottic stenosis in 3 (3.3%), and a variety of other etiologies in 11 (12.2%). Thirty-eight (42%) patients were noted to have stridor. On fiberoptic laryngoscopy, 66 (80%) patients had moderate or severe airway obstruction, whereas 17 (20%) had mild or no obstruction. Of the 72 patients with squamous cell carcinoma, only 6 (8%) have been subsequently decannulated. Among the remainder, 13 of 18 (72%) have been decannulated. Complications occurred in seven (7.8%) patients after awake tracheotomy, none with untoward sequelae. Three severe complications occurred among the seven patients converted from cricothyrostomy to tracheostomy: anoxic brain injury in each, leading to death in two. Conclusions: Awake tracheostomy should be considered in any patient with impending or ongoing airway obstruction or with potential for difficult intubation. This should be performed in a timely manner before an emergent situation arises because the complications of emergency surgical airway can be devastating.
Estimating cost and time of wellbore drilling for Engineered Geothermal Systems (EGS) – Considering uncertainties

Abstract Wellbore drilling for any resource extraction—and particularly for EGS—is subject to many uncertainties, ranging from those related to geology to those related to the drilling procedures. Since well drilling and related subsurface activities for EGS represent a significant portion (above 50%) of the total EGS development cost, assessing the risk is essential. This requires that one can estimate the cost and time uncertainties for EGS well drilling. The paper describes a method and associated computer code, the Decision Aids for Tunneling (DAT) that have been adapted to EGS well drilling. Very importantly, the paper shows a detailed application to the case that was originally developed by Sandia National Laboratories. This was done in form of parametric studies, in which uncertainty in cost components, in trouble events, in geology, and in temperature related effects were investigated separately and then in combination. This not only shows that the DAT are well suited for this purpose but it also provides a guideline for interested users. Most importantly, all this shows that wellbore drilling cost and time that are subject to a variety of uncertainties can be systematically assessed.
Hydrocarbons in Open Ocean Waters

Nonvolatile hydrocarbons in Atlantic Ocean and nearby waters were found to contain aromatics at lower concentrations than would be expected if the source of the hydrocarbons were crude oil or petroleum refinery products. Hydrocarbons appear to persist in the water to varying degrees with the most persistent being the cycloparaffins, then the isoparaffins, and finally the aromatics.
Purine enzyme activities as markers of lymphocytic differentiation: studies of lymphocytes from horses with severe combined immunodeficiency (SCID).

Severe combined immunodeficiency (SCID) occurs in horses of the Arabian breed and is inherited as an autosomal recessive trait1. Affected foals are severely lymphopenic with an absence of functional B and T lymphocytes.2 The few lymphocytes that can be found in affected foals resemble large granular lymphocytes (LGL) and can be grown long-term with media containing interleukin-2 (IL-2).3 The disorder is restricted to the lymphoid system, as other leukocytes are functionally and quantitatively normal.4
Role of C-reactive protein in acute lung injury

Excessive inflammation caused by unregulated inflammatory processes can lead to disease. One example of this is seen in acute lung injury in which an individual is unable to regulate an inflammatory response in the lungs, with the net effect of self-induced tissue injury and loss of organ function. The acute-phase reactant, C-reactive protein, inhibits acute lung injury in animal models and, in this regard, acts as a major anti-inflammatory agent. Therefore, understanding the mechanism by which C-reactive protein elicits this inhibitory effect may provide important information about the design of therapeutic agents for the prevention or treatment of inflammation-mediated tissue injury and resultant loss of organ function.
PHOTOSYNTHETIC RESPONSE OF THE GIANT KELP MACROCYSTIS PYRIFERA (PHAEOPHYCEAE) TO ULTRAVIOLET RADIATION1

Solar ultraviolet radiation (UVA + UVB) impairs photosynthesis in marine algae. Canopy blades of the giant kelp Macrocystis pyrifera (L.) C. Agardh are exposed to high levels of solar UV in the field. To determine the effects of UV radiation on photosynthesis in the giant kelp and to identify sites of UV damage, O2 evolution, reaction center organization, light harvesting, and energy transfer efficiency were measured in canopy blades that had been exposed to elevated levels of UV in the laboratory. UV treatment reduced both the light-saturated rate and the light-limited rate of photosynthesis by 50% but produced no significant change in the rate of dark respiration. A significant impairment of photosystem II (PSII) reaction center function was observed, suggesting that PSII is a major site of damage in chromophytes. Reduced quantum efficiency of photosynthesis and loss of energy transfer from light-harvesting pigments (fucoxanthin, chlorophyll a, and chlorophyll c) to PSII indicate that the major light-harvesting complex of M. pyrifera, the fucoxanthin-chlorophyll protein complex (FCPC), was another site of UV damage. These measures provide the first evidence of a direct effect of UV radiation on specific sites in the photosynthetic apparatus of chromophytes and indicate that in situ fluorescence excitation analysis may be a simple means to detect UV stress in algae.
Evolution's Pedagogy: An Adaptationist Model of Pretense and Entertainment

The portrayal of the actions of fictive characters for purposes of entertainment is a familiar phenomenon. Theories that seek to explain why we are attracted to such fictions and whether we learn from them have produced no consensus and no adequate overall account. In this paper, we present the hypothesis that entertainment relies on cognitive adaptations for pretend play. As a simplified model system, we draw on our field study of children's chase play, which is characterized by an elementary form of pretense. The children pretend, at first without consciously representing their pretense, to be chased by predators. The details of this behavior, widespread among mammals, indicate that the biological function of the game may be to train predator-evasion strategies. Chase play, we suggest, evolved in early mammals because it enabled cheap and plentiful resources to be used to train strategies for events that are rare, dangerous, and expensive. More generally, we argue that pretense is used to access spaces of possible actions in order to locate and practice new strategies. It relies on the creation of a simulated scenario and requires sophisticated source monitoring. The simulation is experienced as intrinsically rewarding; boredom is a design feature to motivate the construction of a more appropriate pedagogical situation, while the thrill of play signals optimal learning conditions. The conscious narrative elaboration of chase games involves an elementary form of role play, where we propose a virtual agent is created that tracks and acts on the memories required for coherent action within the simulation. These complex if familiar design features, we suggest, provide a minimalist functional and adaptationist account of the central features of entertainment: that it is fun, that it involves us imaginatively and emotionally, and that it has a tacit pedagogical effect. The model provides a principled and testable account of fiction-based entertainment grounded in evolutionary and cognitive processes.
Tariquidar (TAR, XR‐9576) selectively inhibits P‐glycoprotein (P‐gp) in t‐lymphocytes compared to that in the blood‐brain barrier (BBB)

Background Modulation of P-gp in humans has been hampered by the lack of potent and selective inhibitors. TAR does not have these limitations, thus, certain of its in vivo effects were investigated. Methods A double-blind, placebo controlled study was performed in 9 healthy subjects following an initial dose-finding/safety study with oral loperamide (LOP). Intravenous TAR (150 mg over 30 min) or placebo was given on different days followed 30 min later by oral LOP (32 mg). Pupil diameter was determined prior to and every 30 min for 12 hr; serial plasma samples for measurement of LOP levels and the ex vivo efflux of the fluorescent dye DiOC2(3) were obtained over the same period. Results TAR had no effect on LOP's plasma levels, however, it rapidly produced over 90% inhibition of P-gp mediated efflux of DiOC2(3) in T-lymphocytes that was maintained over the study period. Considerable interindividual variability in LOP's effect on the change in pupil diameter was observed which appeared to be related to the opioid's plasma level. Even in “responders”, however, TAR did not change the extent of the pupillary effect. Conclusions Despite producing nearly complete inhibition of P-gp function in T-lymphocytes, TAR had negligible effect on the BBB and brain uptake of LOP. The reason(s) for such selectivity is unknown, but suggests that modulation of brain uptake of P-gp substrates may be more difficult than previous animal studies suggest. Clinical Pharmacology & Therapeutics (2005) 77, P39–P39; doi: 10.1016/j.clpt.2004.12.041
Marinobufagenin, resibufogenin and preeclampsia

Abstract The bufodienolides are cardiac glycosides which have the ability to inhibit the enzyme, Na + /K + ATPase (sodium potassium adenosine triphosphatase). They are cardiac inotropes, cause vasoconstriction (and, potentially, hypertension) and are natriuretic. Evidence has accrued over time which supports the view that they are mechanistically involved in volume expansion-mediated hypertension. In this communication, the authors summarize data which support the view that the bufodienolides and, in particular, marinobufagenin (MBG) are involved in the pathogenesis of preeclampsia. In a rat model of the syndrome, MBG causes hypertension, proteinuria, intrauterine growth restriction and increased weight gain. All of these phenotypic characteristics are prevented by an antagonist to MBG, resibufogenin (RBG). The “preeclamptic” animals also develop a vascular leak syndrome, resulting in hemoconcentration. Abnormalities in the MAPK (mitogen-activated protein kinase) system play a role in the mechanism by which MBG produces the abnormalities in the pregnant rat. Studies to discover the relevance of these findings to human preeclampsia are currently underway in several laboratories and clinics.
Ensembles of uncertain mathematical models can identify network response to therapeutic interventions

The role of mechanistic modeling and systems biology in molecular medicine remains unclear. In this study, we explored whether uncertain models could be used to understand how a network responds to a therapeutic intervention. As a proof of concept, we modeled and analyzed the response of the human coagulation cascade to recombinant factor VIIa (rFVIIa) and prothrombin (fII) addition in normal and hemophilic plasma. An ensemble of parametrically uncertain human coagulation models was developed (N = 437). Each model described the time evolution of 193 proteins and protein complexes interconnected by 301 interactions under quiescent flow. The 467 unknown model parameters were estimated, using multiobjective optimization, from published in vitro coagulation studies. The model ensemble was validated using published in vitro thrombin measurements and thrombin measurements taken from coronary artery disease patients. Sensitivity analysis was then used to rank-order the importance of model parameters as a function of experimental or physiological conditions. A novel strategy for the systematic comparison of ranks identified a family of fX/FXa and fII/FIIa interactions that became more sensitive with decreasing fVIII/fIX. The fragility of these interactions was preserved following the addition of exogenous rFVIIa and fII. This suggested that exogenous rFVIIa did not alter the qualitative operation of the cascade. Rather, exogenous rFVIIa and fII took advantage of existing fluid and interfacial fX/FXa and fII/FIIa sensitivity to restore normal coagulation in low fVIII/fIX conditions. The proposed rFVIIa mechanism of action was consistent with experimental literature not used in model training. Thus, we demonstrated that an ensemble of uncertain models could unravel key facets of the mechanism of action of a focused intervention. Whereas the current study was limited to coagulation, perhaps the general strategy used could be extended to other molecular networks relevant to human health.
Antenna optimization for vehicular environments

This paper presents a multi-antenna optimization for communication in a Rockwell T-39 Sabreliner, a mid-size aircraft with a metallic body. The aircraft channel at 2.45 GHz is modeled using site specific 3D ray-tracing software. Added effects from system details including the antenna radiation patterns, mutual coupling, etc. are incorporated into a network theory based detailed signal model. The paper considers traditional antennas including dipoles, square patches, PIFAs, and polarization agile patches along with some more complex shaped patches and PIFAs. A random search algorithm was used to optimize capacity for arrays with widely divergent element count, element type, matching, directivity, polarization alignment, efficiency, spatial correlation and coupling. The polarization agile patch provides the best capacity for locations near the aircraft ceiling while the PIFAs with more variety in shape (spiral shapes) provide the best capacity for locations near the floor. This is because the signals reaching the roof and sides contain more polarization diversity than those in the center of the body where the nonconductive floor is located.