cssi/SciSciGPT-SciSciNet huggingface dataset:
Effects of field broadening and pump line selection on multi-level absorption in molecular systems

Abstract The problem of multi-level absorption of i.r. laser radiation in polyatomic gases is examined using the density matrix formalism. The general condition under consideration is that field broadening effects are significant, but the detailed and discrete features of the absorption spectra remain very important. Collisional effects are taken into account through macroscopic relaxation terms, but the cumulative effects of collisional relaxation are assumed to cause only minor perturbations to the overall vibrational-rotational populations over the optical pumping time scale of interest. Various approximate formulae are then derived for locating the optimum frequency for optical pumping of three consecutive anharmonic vibrational levels within a given normal mode and for predicting the intensity- and frequency-dependence of the resultant uppermost level population density during a quasi-steady state balance among the absorption, stimulated emission, dephasing collision and rotational relaxation rates. Numerical examples are illustrated for pumping of the three lowest vibrational levels within the non-degenerate asymmetric stretching mode of the linear triatomic molecule CO2 for which the absorption spectra are relatively simple and well known. Some possible applications of these results to the problem of i.r. laser frequency conversion and to the interpretation of wavelength-selective i.r. photodissociation recently observed in many symmetric top molecules, such as BCl3, SiF4 and SF6 for which the absorption spectra are much more complex and the spectroscopic constants much less certain, are also discussed.
Wave propagation through a turbulent wake

Abstract Expressions are derived for the mean squared value of the phase fluctuations of a wave which has propagated through a turbulent wake. It is assumed that the index of refraction fluctuations within the wake can be approximated as the product of a random function and a decaying exponential.
Bug Infestation!: A Goal-Plan Analysis of CS2 Students' Recursive Binary Tree Solutions

A goal-plan analysis was conducted to examine the variety of plans students use in writing a recursive method for an operation on a binary search tree. Students were asked to write a recursive method to count the nodes in a binary search tree with exactly one child. The problem incorporated two goals: traversing the tree and counting nodes with one child. Three traversal plans and four counting plans were observed in student solutions. Over half of the students used the arm's-length recursion plan, which involves testing for the base case before it is actually reached in order to avoid making recursive calls. This strategy creates complex and error prone code. Making students aware of arm's-length recursion may help them avoid introducing bugs into their recursive code. Although nearly all of the 18 participants demonstrated viable plans for solving the problem, their solutions contained a variety of errors: 55 total errors of 15 types. Students had particular difficulty with base cases, misplaced calculations, and missing method calls. Knowledge of these errors can be useful for instructors when developing lecture examples, identifying distractors for peer instruction multiple-choice questions and for designing homework exercises. Instructors can counteract these problems by providing a variety of recursive examples.
A synthesis of aaptamine

Abstract A five-step synthesis of the unusual marine alkaloid aaptamine ( 1 ) from veratrole is described (Scheme 1).
Potential surfaces from the inversion of time dependent probability density data

This article presents an algorithm to assess the feasibility of inverting probability density data to extract potential surfaces. Such data admit the generation of a noniterative quantum inversion algorithm that does not require the solution of the Schrodinger equation. Tikhonov regularization is employed to manage the singular nature of the problem. The inversion in regular regions has excellent accuracy, and an error analysis also indicates that the potential in the regular regions is stable under perturbations from noisy data. The regular regions of the potential are identified by the algorithm. The algorithm does not require knowledge of the excitation process initiating the evolution of the system. Analysis indicates that the most detailed potential surface information will result from broadband excitation leaving the molecule with significant population in as many quantum states as possible. The inversion algorithm is tested in a simulation for the O–H potential, which shows that the algorithm is ve...
A Latent Contingency Table Approach to Dose Finding for Combinations of Two Agents

Two-agent combination trials have recently attracted enormous attention in oncology research. There are several strong motivations for combining different agents in a treatment: to induce the synergistic treatment effect, to increase the dose intensity with nonoverlapping toxicities, and to target different tumor cell susceptibilities. To accommodate this growing trend in clinical trials, we propose a Bayesian adaptive design for dose finding based on latent 2 x 2 tables. In the search for the maximum tolerated dose combination, we continuously update the posterior estimates for the unknown parameters associated with marginal probabilities and the correlation parameter based on the data from successive patients. By reordering the dose toxicity probabilities in the two-dimensional space, we assign each coming cohort of patients to the most appropriate dose combination. We conduct extensive simulation studies to examine the operating characteristics of the proposed method under various practical scenarios. Finally, we illustrate our dose-finding procedure with a clinical trial of agent combinations at M. D. Anderson Cancer Center.
Conceptions of the Market in Post-Mao China: An Interpretive Essay

Since late 1978, when China adopted modernization as its new development objective, many economic reforms have been introduced. The reforms are still ongoing, and their ultimate impact on the economy may be profound and far-reaching. Initial results from the agricultural sector indicate that the reforms in the rural areas have already produced impressive results in terms of raising peasant incentives and productivity. Although the reforms cover a wide area-agricultural responsibility system, tax reforms, greater enterprise autonomy, foreign investment, more free markets, and so on-the central underlying strategy is the combination of planning with the market mechanism in order to impart greater economic incentives and flexibility to the economic system, thereby raising productivity in all sectors of the economy. This introduction of the market mechanism into a society that has been hitherto ideologically
Analysis of Hubble Space Telescope Reaction Wheel Lubricant

The results of analyses of the lubricant from the Hubble Space Telescope reaction wheel bearings indicated that the lubricant was in excellent condition and that there was no mechanical distress. Evaporative loss of oil was measured and was consistent with the loss predicted by our oil evaporation analytical model. It is expected that the reaction wheel would have performed mechanically for manymore than the seven years accumulated on orbit.
Damage initiation under transverse loading of unidirectional composites with arbitrarily distributed fibers

Abstract A limiting property governing the thermomechanical behavior of composites is the strength transverse to the fibers. The present study investigates the dependence of this property on the distribution of fibers in the cross-section of a unidirectional composite. The approach taken is to consider actual distributions, which are arbitrary and are not necessarily described by random or periodic distributions. A fundamental issue in studying non-uniform distributions is the size of a representative volume element (RVE). By the use of an actual radial distribution function obtained for a ceramic-matrix composite by quantitative stereology in conjunction with a simulation technique developed in this study, the RVE size is investigated with respect to initiation of debonding and radial matrix cracking – two basic mechanisms governing the transverse strength of composites. Tensile loading transverse to the fibers and residual stresses induced by thermal cooldown are considered separately as loading modes for transverse failure. The results provide some useful insight into the importance of non-uniformity of fiber spatial distribution with regard to the transverse failure of composites.
Power distribution in industrial complexes

Every industrial distribution system has its own particular problems, which affect the final layout, but it is possible to lay down certain basic guidelines. In particular, the use of standard ranges of distribution switchgear is a significant factor in economic design.
Multilevel Factor Analysis and Structural Equation Modeling of Daily Diary Coping Data: Modeling Trait and State Variation

The current study used multilevel modeling of daily diary data to model within-person (state) and between-person (trait) components of coping variables. This application included the introduction of multilevel factor analysis (MFA) and a comparison of the predictive ability of these trait/state factors. Daily diary data was collected on a large (n = 366) multiethnic sample over the course of five days. Intraclass correlation coefficient for the derived factors suggested approximately equal amounts of variability in coping usage at the state and trait levels. MFAs showed that Problem-Focused Coping and Social Support emerged as stable factors at both the within-person and between-person levels. Other factors (Minimization, Emotional Rumination, Avoidance, Distraction) were specific to the within-person or between-person levels, but not both. Multilevel structural equation modeling (MSEM) showed that the prediction of daily positive and negative affect differed as a function of outcome and level of coping factor. The Discussion section focuses primarily on a conceptual and methodological understanding of modeling state and trait coping using daily diary data with MFA and MSEM to examine covariation among coping variables and predicting outcomes of interest.
Studies on possible mechanisms of programmed cell death in the chick embryo

Summary The cytological effects of DNA crosslinking agents, such as mitomycin C, nitrogen mustards, diepoxides, and dialkyl sulfonates were tested on 4-day chick embryos. At low dosage 12 of 14 of these agents produced cells morphologically identical to those found in naturally occurring areas of cellular death, e.g., the posterior necrotic zone (PNZ) and the presumptive interdigital spaces. Monofunctional analogs of the difunctional agents failed to produce the same type of cells at equivalent and higher doses. Other metabolic poisons, including actinomycin D, acridine orange, cycloheximide, colchicine, purine analogs, and cyanide were also negative; two exceptional compounds were daunomycin and hydroxyurea, both of which at moderate doses had the same cytological effects as the alkylating agents. Mitomycin C had the additional effect of producing severe quadrilateral phocomelia. An increased content of crosslinked DNA was detected in embryos treated with difunctional agents using the polyethylene glycoldextran phase separation procedure. Melting profiles and cesium sulfate equilibrium density gradients confirmed the bihelical nature of the renatured crosslinked DNA fractions. Examination of DNA isolated from presumptive interdigital spaces at several stages up to and including the stage of maximum cell death, revealed no increase in crosslinked DNA in these regions relative to controls. However, the number of effective crosslinks per cell could be well below the level of detection of the assay; thus the crosslinking hypothesis as a mechanism for programmed cell death in the chick embryo cannot be eliminated. Since crosslinking agents, daunomycin, and hydroxyurea are known to block the normal progress of the cell through its cycle, perhaps the cause of programmed cell death might be a similar block; other hypotheses are considered.
Toward a Model of the Office Building Sector

High rise office buildings represent large capital outlays in very competitive markets. Investment and development decisions require careful market analysis to assure sufficient demand to lease the office space at rental rates which will make the venture financially attractive. Present methodology for analyzing future commercial real estate market conditions can at best be said to be inadequate. This methodology relies on concepts such as “market absorption” rates and “normal” vacancy rates. These concepts usually rely on accounting type and trend line techniques to provide forecasts of space demand. In this paper we provide an alternative methodology for forecasting the key variables in the office space market by developing a statistical model of supply and demand. The key variables that need to be forecasted are the stock of office space (in square feet), the flow of new office construction (in square feet), the vacancy rate (in percent), and the rent for office space (net rent per square foot).
From Aggression to Just Occupation? The Temporal Application of Jus Ad Bellum Principles and the Case of Iraq

Abstract This paper considers whether an act of aggression can subsequently become a justified occupation. I use John Lango's theory of the temporalization of just war principles to argue that the jus ad bellum criteria should be reapplied over time, such that they can be newly met over the course of an intervention. Discussing each traditional principle of jus ad bellum, I outline inherent challenges in remaking an unjust war as a valid humanitarian intervention. In particular, I argue that right authority is a complex and difficult hurdle for a former aggressor's occupation. The US occupation of Iraq is used as an example of an intervention that initially violated most or all just war principles but came to satisfy them during later phases of the occupation. This paper contributes not only to the question of how to apply just war principles over time but also to the underdeveloped ethics of occupation and jus post bellum.
The Middle X Residue Influences Cotranslational N-Glycosylation Consensus Site Skipping

Asparagine (N)-linked glycosylation is essential for efficient protein folding in the endoplasmic reticulum (ER) and anterograde trafficking through the secretory pathway. N-Glycans are attached to nascent polypeptides at consensus sites, N-X-T/S (X ≠ P), by one of two enzymatic isoforms of the oligosaccharyltransferase (OST), STT3A or STT3B. Here, we examined the effect of the consensus site X and hydroxyl residue on the distributions of co- and post-translational N-glycosylation of a type I transmembrane glycopeptide scaffold. Using rapid radioactive pulse–chase experiments to resolve co-translational (STT3A) and post-translational (STT3B) events, we determined that NXS consensus sites containing large hydrophobic and negatively charged middle residues are frequently skipped by STT3A during protein translation. Post-translational modification of the cotranslationally skipped sites by STT3B was similarly hindered by the middle X residue, resulting in hypoglycosylation of NXS sites containing large hydrophobic and negatively charged side chains. In contrast, NXT consensus sites (barring NWT) were efficiently modified by the cotranslational machinery, reducing STT3B’s role in modifying consensus sites skipped during protein translation. A strong correlation between cotranslational N-glycosylation efficiency and the rate of post-translational N-glycosylation was determined, showing that the OST STT3A and STT3B isoforms are similarly influenced by the hydroxyl and middle X consensus site residues. Substituting various middle X residues into an OST eubacterial homologous structure revealed that small and polar consensus site X residues fit well in the peptide binding site whereas large hydrophobic and negatively charged residues were harder to accommodate, indicating conserved enzymatic mechanisms for the mammalian OST isoforms.
Application of a sediment Toxicity Identification Evaluation in support of Total Maximum Daily Load development for the Calcasieu Estuary

A Toxicity Identification Evaluation of sediments from various reaches of the Calcasieu Estuary in Louisiana was performed to improve the technical basis for Total Maximum Daily Loads under development for this water body. The Toxicity Identification Evaluation methodology involved manipulations of the physical/chemical properties of sediment pore water samples in order to sequentially remove or bind each of the major classes of contaminant compounds and confounding factors. Toxicity tests were performed in conjunction with these manipulations to directly correlate reduction in toxicity with the specifically targeted contaminant classes. Toxicity of sediment porewaters from seven locations was evaluated using the amphipod, Ampelisca abdita and the mysid, Americamysis bahia. Toxicity Identification Evaluation results demonstrated improved survival after filtration, indicating that suspended particulates and associated contaminants were a significant source of toxicity. Subsequent treatments with column ext...
Materials Challenges in Nuclear Energy

Abstract Nuclear power currently provides about 13% of electrical power worldwide, and has emerged as a reliable baseload source of electricity. A number of materials challenges must be successfully resolved for nuclear energy to continue to make further improvements in reliability, safety and economics. The operating environment for materials in current and proposed future nuclear energy systems is summarized, along with a description of materials used for the main operating components. Materials challenges associated with power uprates and extensions of the operating lifetimes of reactors are described. The three major materials challenges for the current and next generation of water-cooled fission reactors are centered on two structural materials aging degradation issues (corrosion and stress corrosion cracking of structural materials and neutron-induced embrittlement of reactor pressure vessels), along with improved fuel system reliability and accident tolerance issues. The major corrosion and stress corrosion cracking degradation mechanisms for light-water reactors are reviewed. The materials degradation issues for the Zr alloy-clad UO 2 fuel system currently utilized in the majority of commercial nuclear power plants are discussed for normal and off-normal operating conditions. Looking to proposed future (Generation IV) fission and fusion energy systems, there are five key bulk radiation degradation effects (low temperature radiation hardening and embrittlement; radiation-induced and -modified solute segregation and phase stability; irradiation creep; void swelling; and high-temperature helium embrittlement) and a multitude of corrosion and stress corrosion cracking effects (including irradiation-assisted phenomena) that can have a major impact on the performance of structural materials.
Fairness and Efficiency in Multiportfolio Optimization

We deal with the problem faced by a portfolio manager in charge of multiple accounts. We argue that because of market impact costs, this setting differs in several subtle ways from the classical single account case, with the key distinction being that the performance of each individual account typically depends on the trading strategies of other accounts, as well. We propose a novel, tractable approach for jointly optimizing the trading activities of all accounts and also splitting the associated market impact costs between the accounts. Our approach allows the manager to balance the conflicting objectives of maximizing the aggregate gains from joint optimization and distributing them across the accounts in an equitable way. We perform numerical studies that suggest that our approach outperforms existing methods employed in the industry or discussed in the literature.
A tactical game for the analysis of complex decision making in individuals and groups.

An experimental simulation is described as a prototype for research concerned with the analysis of human information processing characteristics in complex environments. The method employs a simulated war game environment which lends itself to the analysis of performance and perceptual characteristics of individuals and social groups. Suggestions for procedures, space requirements and measurement techniques are included.
Smaller pelvic volume is associated with postoperative infection after pelvic salvage surgery for recurrent malignancy

BACKGROUND: Patients with recurrent pelvic malignancy have few treatment options, and surgery is fraught with complications. We sought to characterize the relationship between radiographic pelvic volume and postoperative complications after pelvic salvage surgery. METHODS: A retrospective chart review of all patients undergoing pelvic exenteration or abdominoperineal resection for recurrent malignancy between 1998 and 2013 was performed. Preoperative computed tomography was used to determine pelvic volume. RESULTS: Forty-two patients underwent surgery for recurrent rectal (26, 62%), prostate (8, 19%), or anal squamous cell cancer (8, 19%). Thirty-eight patients (90%) suffered complications and there was one (2%) perioperative death. Decreasing pelvic volume was associated with deep or organ space infections (P 5 .01), sepsis (P 5 .03), and fistula (P 5 .05) on univariate analysis. Infections remained significant on multivariate analysis (odds ratio, 1.01; P 5 .02). CONCLUSIONS: Pelvic salvage surgery for recurrent malignancy is associated with a high complication rate yet low mortality. Decreasing pelvic volume is associated with increasing risk of deep or organ space infections.
Uniqueness and bifurcation for solutions of nonlinear Sturm-Liouville eigenvalue problems

A class of nonlinear Sturm-Liouville problems is considered. These problems admit zero as a trivial solution and the nonlinear operator linearized about zero has a purely continuous spectrum [0, ∞). Uniqueness of solutions with a prescribed number of nodes is obtained by a shooting argument. Moreover, combining with the previous existence results, we prove there are infinitely many continua of solutions, which are distinguished by nodal properties, bifurcate from the line of trivial solutions at the lowest point of the continuous spectrum.
Toward practical query pricing with QueryMarket

We develop a new pricing system, QueryMarket, for flexible query pricing in a data market based on an earlier theoretical framework (Koutris et al., PODS 2012). To build such a system, we show how to use an Integer Linear Programming formulation of the pricing problem for a large class of queries, even when pricing is computationally hard. Further, we leverage query history to avoid double charging when queries purchased over time have overlapping information, or when the database is updated. We then present a technique that fairly shares revenue when multiple sellers are involved. Finally, we implement our approach in a prototype and evaluate its performance on several query workloads.
Flight Mechanics of the Wright Aircraft 1903-1912

Perhaps the most curious aspect of the Wright Brothers' program to invent and commercialize the airplane is their decision in 1900 to use their novel canard configuration, and to persist with that geometry until 1910 despite the known deficiency that the aircraft were unstable in pitch. The reasons for their initial choice are well-known. Several studies in the part twenty years have proven beyond doubt that the Wrights did not intentionally make their canards unstable. The pitch instability of their machine was an unwitting byproduct of their design chosen partly out of fear of the conventional design and partly (they reasoned) for more positive control. With their great emphasis on control, the Wrights were able to develop a successful aircraft, albeit difficult to fly additionally because the 1903 aircraft also possessed a fast spiral instability. A canard design is not necessarily unstable, but owing chiefly to their airfoil, and an unfortunate fore-and-aft mass distribution, the Wright canards were all unstable. Though easier to fly, their 1909 aircraft was more unstable than the famous 1903 Flyer and the Brothers did not have a stable design until they finally adopted a conventional aft horizontal tail in 1910. Successful control of the canard aircraft depended heavily on large damping-in-pitch. The purpose of this paper is to apply modern analysis of flight mechanics to trace the detailed flying characteristics of their powered aircraft from 1903 to 1910 when they finally gave up the canard. Its a story in which technology, stubborness and commercialization are intimately mingled; we are concerned here only with the technology.
Age and Word Frequency Effects in Continuous Recognition Memory

Fifty-seven males representing groups with median ages of 20, 52, and 63 years were presented with a long sequence of words. Using a four point scale, they judged whether each word was presented for the first ("new") or second ("old") time in the sequence. High and low frequency words and separations of 0 to 64 words between the two presentations of a given word were employed. Analyses of errors confidence judgments and decision times revealed minimal or no age difference when the number of words intervening between successive presentations did not exceed the span of immediate memory. Older subjects' performance declined more rapidly than younger subjects from 3 to 12 second retention intervals, but declined at about the same rate from 12 to 192 second retention intervals. Low frequency words were better remembered by all age groups and there was no interaction between the effects of age and word frequency in any dependent measure.
Marketing for hospitality & tourism and tourism marketing a comparative review of two marketing textbooks from an Asian perspective

Marketing for Hospitality and Tourism. By Philip Kotler, John Bowen and James Maken, Prentice‐Hall. (Upper Saddle River, NJ 07458) ISBN: 0–13–395625–3, 1996, xv + 704‐pp. (tables, charts, photographs, references, index) $ 70.00 (hardcover). Tourism Marketing. By Les Lumsdon, International Thomson Business Press. (Berkshire House, 168–173 High Holbora, London WC1V 7AA, UK) ISBN: 1–86152–045‐X, 1997, xiv + 290‐pp. (tables, charts, references, select bibliography, index) $ 32.95 (soft).
Complicating the Local: Defining the Aymara at Tiwanaku, Bolivia

The archaeological site of Tiwanaku, Bolivia, is commonly held to be the “Spiritual Capital of the Aymara People.” But negotiating who qualifies as Aymara, and in what contexts, is decidedly more complicated. Local political divisions between residents of the village of Tiahuanacu (who are seen locally as less-Aymara but not as not-Aymara) and residents of the surrounding rural communities (who are considered to be unquestionably Aymara) structure discussions about who has the right to earn income at the Tiwanaku archaeological site, who manages major public events, and who is responsible for the site’s maintenance and security. The situation is complicated further by national-level events such as the Winter Solstice, where urban Aymara travel to Tiwanaku to seek their roots, and Bolivian Presidents and politicians come to participate in national Aymara “culture.” I focus on the intervencion (“Intervention”) that took place in Tiahuanacu in August 2000, which resulted in the transfer of management of the Tiwanaku archaeological site from the Bolivian state to local municipal and indigenous authorities. Heritage researchers should take such local divisions into account, rather than assuming that “locals” are politically unified or easily delineated by geographical boundaries.
[3H] prostaglandins binding to dispersed bovine luteal cells: evidence for discrete prostaglandin receptors.

Abstract Suspensions of dispersed bovine luteal cells prepared by collagenase digestion of luteal tissue specifically bound [3H]Prostaglandin (PG) E1 and [3H]PGF2α. While the number of sites per cell (∼ 1.8 × 105) were about the same for both [3H]PGs, the apparent Kds were different: [3H]PGE1 − 2.4 nM; [3H]PGF2α − 11 nM. The [3H]PGs binding was inhibited in a dose-dependent manner in the presence of increasing concentrations of unlabeled PGs. Potency order for inhibition of [3H]PGE1 binding was: PGE2 > PGE1 > PGF2α > PGF1α. The corresponding data for [3H]PGF2α was: PGF2α > PGF1α > PGE2 > PGE1. While [3H]PGE1 and [3H]PGF2α bind to their own receptors with high affinity, their affinities for each other's binding were extremely low. Thus, these results demonstrate that luteal cells, like plasma membranes isolated from luteal tissue, contain receptors for PGEs and PGF2α which are discrete with respect to specificity and affinity.
Effect of altering smooth muscle tone on maximal expiratory flows in patients with tracheomalacia

We obtained maximal partial expiratory flow-volume (PEFV) curves using the rapid compression technique in three infants with intrathoracic tracheomalacia. Maximum flows were quantitated at functional residual capacity (VmaxFRC). Studies were performed at baseline, after inhalation of methacholine (MCh) and after inhalation of albuterol. At baseline, all three patients had significantly lower than normal VmaxFRC values, and two patients displayed expiratory flow limitation during tidal breathing. VmaxFRC improved significantly after MCh administration, but fell back toward or below baseline after albuterol. Additionally, the ratio of forced to tidal flows at mid-tidal volume (Vmid(forced/tidal), a reflection of expiratory flow reserve, increased after MCh administration and decreased after albuterol. Two patients also received oral bethanechol: 2.9 mg/M2, q 8 hr for 10 days, after which PEFV curves were repeated. Both Vmax FRC and Vmid(forced/tidal) were increased over baseline after bethanechol administration, but decreased after albuterol. These results suggest that in patients with abnormally collapsible tracheae, stimulation of tracheal smooth muscle can improve airway stability, thereby increasing forced expiratory flows. Additionally, relaxation of airway smooth muscle by bronchodilators can have the opposite effect and exacerbate obstruction.
Computer models of the growth of monolayers

Preliminary results from a novel reversible computer model of monolayer nucleation and growth are compared with extant irreversible computer models of monolayer growth's early process stages. Attention is given to the microstructures resulting from direct impingement, the cluster density attributable to direct impingement, microstructures resulting from impingement combined with surface migration, and the cluster density attributable to impingement in combination with surface migration.
A problem-solving approach to preparing professional presentations

This paper describes a systematic approach to preparing presentations that uses a four-step problem-solving method familiar to most professionals. Step 1, understanding the problem, involves analyzing the speaker's purpose, the character of the audience, and the demands of the situation. Step 2, devising a plan, consists of selecting a strategy to integrate information from the first step with the speaker's knowledge of the subject. Step 3, carrying out the plan, uses conventional techniques of organization, explanation, and visual representation to compose a draft of the presentation. Step 4, examining the solution, compares the draft with the plan and modifies the presentation in response to feedback.
824 RESPIRATORY COMPROMISE AS A MAJOR CAUSE OF MORBIDITY AND MORTALITY IN HUNTER SYNDROME

Eleven patients with Hunter Syndrome (MPS II) have been followed at the University of Connecticut, of which 10 have been placed on a monthly leukocyte transfusion protocol. Positive effects of the transfusions have included softening of the skin and hair with resolution of nodular skin lesions and diarrhea. We have also noted marked subjective improvement of joint discomfort in those individuals who are able to communicate. No significant improvement of macroglossia, organomegaly, skeletal, cardiovascular or pulmonary changes have been noted. Previously, it was felt that mortality in Hunter syndrome was frequently secondary to cardiovascular complications. Our recent experience with 11 patients has shown that the major morbidity is related to respiratory disease, especially with regard to upper airway compromise. Because of the unusual tracheal cartilage conformation which develops in these individuals, tracheostomy has been necessary in 5/11 patients including 2/3 individuals with the mild form of Hunter syndrome. Tracheostomy is a complex procedure in these patients requiring non-standard techniques and appliances. These findings suggest that pulmonary abnormalities may be the primary cause of mortality in Hunter Syndrome. We are also considering that this change in the locus of morbidity may be due to the delay of cardiovascular decompensation secondary to the leukocyte transfusions.
In Appreciation Julian Schwinger: From Nuclear Physics and Quantum Electrodynamics to Source Theory and Beyond

Julian Schwinger’s influence on twentieth-century science is profound and pervasive. He is most famous for his renormalization theory of quantum electrodynamics, for which he shared the Nobel Prize in Physics for 1965 with Richard Feynman and Sin-itiro Tomonaga. This triumph undoubtedly was his most heroic work, but his legacy lives on chiefly through subtle and elegant work in classical electrodynamics, quantum variational principles, proper-time methods, quantum anomalies, dynamical mass generation, partial symmetry, and much more. Starting as just a boy, he rapidly became one of the preeminent nuclear physicists in the world in the late 1930s, led the theoretical development of radar technology at the Massachusetts Institute of Technology during World War II, and soon after the war conquered quantum electrodynamics, becoming the leading quantum-field theorist for two decades, before taking a more iconoclastic route during the last quarter century of his life.
New roles for connexons

Connexons or gap junction hemichannels are large, nonselective ion channels that reside in the nonjunctional plasma membrane before their assembly into gap junction channels. Increasing evidence su...
A PROPOSED METHOD FOR SHIP ROUTING USING LONG RANGE WEATHER FORECASTS

Two advances in the calculus of variations method for minimal time ship routing are described. The first is a scheme for constructing ocean wave field forecasts which may be expected to have considerable skill for perhaps a week. The second is an improved technique for varying time extremal ship tracks toward admissibility. Both ideas are illustrated by calculating the optimum track ship route of a VC2AP3 vessel on a transpacific voyage. Possible future developments are discussed.
Multiple components in ink of the sea hare Aplysia californica are aversive to the sea anemone Anthopleura sola

Abstract Sea hares of the genus Aplysia rely on an array of behavioral and chemical defenses, including the release of ink and opaline, to protect themselves from predation. While many studies have demonstrated that ink and opaline are repellent to predators, very little is known about which components of these secretions are active against predators. Ink was previously shown to facilitate the escape of Aplysia from predatory anemones ( Anthopleura ) by eliciting tentacle retraction and/or shriveling, and gastrovascular eversion, but the metabolites mediating this interaction were not identified. We investigated the metabolites in Aplysia californica secretions that were aversive to the anemone Anthopleura sola , as demonstrated by tentacle shriveling and/or retraction. We found that ink elicited tentacle shriveling and/or retraction, while opaline elicited a feeding response. The active components in ink do not appear to be diet-dependent, as ink was aversive regardless of diet (natural seaweed diet vs. Gracilaria ferox ). Furthermore, metabolites extracted from G. ferox were not aversive, suggesting that the aversive components are produced by the sea hares. We then examined escapin, a protein in ink with antimicrobial properties. Escapin quickly forms reaction products when mixed with the amino acids l -lysine and l -arginine, which would occur when ink and opaline are released into the sea hare mantle cavity. Neither escapin alone nor escapin mixed with its amino acid substrate l -lysine elicited aversive behaviors either immediately before or 2 min before applying to the tentacles. In addition, escapin mixed with opaline and applied to tentacles after 2 min did not elicit a significant aversive response. Using bioassay-guided fractionation, we attempted to isolate the components in A. californica ink that are aversive to A . sola . We determined that multiple components in ink, including both lipophilic and hydrophilic constituents, elicited aversive responses. We hypothesize that these components may facilitate A . californica 's escape from A. sola by eliciting tentacle shriveling and/or retraction, which lead to anemones dropping ensnared sea hares.
Patterns of Communication Breakdowns Resulting in Injury to Surgical Patients

Background Communication breakdowns are a common threat to surgical safety, but there are little data to guide initiatives to improve communication. Study design In surgeon-review of 444 surgical malpractice claims from 4 liability insurers, we identified 60 cases involving communication breakdowns resulting in harm to patients. Two surgeon-reviewers analyzed these cases to identify common characteristics and associated factors. Based on identified patterns, potential interventions to prevent communication breakdowns were developed and their potential impact was assessed. Results The 60 cases involved 81 communication breakdowns, occurring in the preoperative (38%), intraoperative (30%), and postoperative periods (32%). Seventy-two percent of cases involved one communication breakdown. The majority of breakdowns were verbal communications (92%) involving 1 transmitter and 1 receiver (64%). Attending surgeons were the most common team member involved. Status asymmetry (74%) and ambiguity about responsibilities (73%) were commonly associated factors. Forty-three percent of communication breakdowns occurred with handoffs and 39% with transfers in the patient's location. The most common communication breakdowns involved residents failing to notify the attending surgeon of critical events and a failure of attending-to-attending handoffs. Proposed interventions could prevent 45% to 73% of communication breakdowns in this cases series. Conclusions Serious communication breakdowns occur across the continuum of care, typically result from a failure in verbal communication between a surgical attending and another caregiver, and often involve ambiguity about responsibilities. Interventions to prevent these breakdowns should involve: defined triggers that mandate communication with an attending surgeon; structured handoffs and transfer protocols; and standard use of read-backs.
The Developmental Theory of the Gender Gap: Women's and Men's Voting Behavior in Global Perspective

Studies carried out in many countries in previous decades found that women were more conservative than men and less likely to participate in politics. Here, it is examined whether this traditional gender gap persists today, or whether gender cleavages in the electorate have converged, and whether the phenomenon of the modern gender gap, with women more left wing, has become evident elsewhere. The article draws on evidence from the World Values Surveys in the early 1980s, and the early and mid-1990s carried out in over sixty countries around the world. This study establishes that gender differences in electoral behavior have been realigning, with women moving toward the left of men throughout advanced industrial societies (though not in postcommunist societies or developing countries) and explores the reasons for this development, including the role of structural and cultural factors. The conclusion considers the political implications of the findings.
The Effect of Time and Frequency of Static Stretching on Flexibility of the Hamstring Muscles

Background and Purpose. Frequency and duration of static stretching have not been extensively examined. Additionally, the effect of multiple stretches per day has not been evaluated. The purpose of this study was to determine the optimal time and frequency of static stretching to increase flexibility of the hamstring muscles, as measured by knee extension range of motion (ROM). Subjects. Ninety-three subjects (61 men, 32 women) ranging in age from 21 to 39 years and who had limited hamstring muscle flexibility were randomly assigned to one of five groups. The four stretching groups stretched 5 days per week for 6 weeks. The fifth group, which served as a control, did not stretch. Methods. Data were analyzed with a 5 × 2 (group × test) two-way analysis of variance for repeated measures on one variable (test). Results. The change in flexibility appeared to be dependent on the duration and frequency of stretching. Further statistical analysis of the data indicated that the groups that stretched had more ROM than did the control group, but no differences were found among the stretching groups. Conclusion and Discussion. The results of this study suggest that a 30-second duration is an effective amount of time to sustain a hamstring muscle stretch in order to increase ROM. No increase in flexibility occurred when the duration of stretching was increased from 30 to 60 seconds or when the frequency of stretching was increased from one to three times per day.
Analysis of the contribution of cellular and viral RNA to the packaging of APOBEC3G into HIV-1 virions.

Background: Efficient incorporation of the cellular cytidine deaminase APOBEC3G (APO3G) into HIV-1 virions is necessary for its antiviral activity. Even though cellular RNAs are known to be nonspecifically incorporated into virus particles, we have previously found that encapsidation of APO3G into HIV-1 virions is specifically enhanced by viral genomic RNA. Intracellularly, APO3G was found to form large RNA-protein complexes involving a variety of cellular RNAs. The goal of this study was to investigate the possible contribution of host RNAs recently identified in intracellular APO3G ribonucleoprotein complexes to APO3G's encapsidation into HIV-1 virions. Results: Our results show that 7SL RNA, a component of signal recognition particles, and hY1, hY3, hY4, hY5 RNAs were present in intracellular APO3G complexes and were packaged into HIV1 particles lacking viral genomic RNA unlike APO3G, which was not packaged in significant amounts into genomic RNA-deficient particles. These results indicate that packaging of 7SL or hY RNAs is not sufficient for the packaging of APO3G into HIV-1 virions. We also tested the encapsidation of several other cellular RNAs including β-actin, GAPDH, α-tubulin, and small nuclear RNAs and determined their effect on the packaging of APO3G into nascent virions. Again, we were unable to observe any correlation between APO3G encapsidation and the packaging of any of these cellular RNAs. Conclusion: The results from this study support our previous conclusion that viral genomic RNA is a critical determinant for APO3G incorporation into HIV-1 virions. While most cellular RNAs tested in this study were packaged into viruses or virus-like particles we failed to identify a correlation between APO3G encapsidation and the packaging of these cellular RNAs.
College Persistence and Engagement in Light of a Mature English Language Learner (ELL) Student's Voice.

An interview study at a community college in the mid-Atlantic region of the United States reveals factors in the persistence of English language learners (ELLs) starting from their courses in English as a second language (ESL) through to their graduation or transfer to 4-year institutions. The results form a narrative of a day in the life of a mature ELL woman and continue by reporting the primary reasons that ELLs either remained in or left the community college. Students talked about 3 main obstacles to remaining enrolled: full-time jobs, family obligations, and lack of finances, all of which are common factors for community college students. But particular to ELLs were their feelings of marginalization at the college because of their multilingual identities and linguistic struggles in their ESL and subject classes. The study closes with suggestions on ways for everyone at the college to assist ELLs in succeeding along their college trajectories. Community college faculty and administrators can work tog...
Human growth hormone measurement by means of a sensitive ELISA of whole blood spots on filter paper

Abstract Background Measurements of human growth hormone (hGH) are a prerequisite for identifying a deficiency or excess. Our study is the first to investigate the reliability of a very sensitive assay for the quantification of GH in dried blood spots on filter paper. Objective Validation of a commercially-available enzyme-linked immunoassay (ELISA) for measuring hGH from filter paper samples of dried blood. Methods We used an assay system (ELISA, E022, Mediagnost) based on polyclonal rabbit antibodies. Its suitability is ascribable to its very high sensitivity (1.6ng/L) and virtual absence of interfering factors, excepting for a cross-reactivity with high pegvisomant concentrations. Results hGH was found to be stable in dried blood spots on filter paper (No. 903, Whatman) over eight days at 37°C. Extraction of hGH from filter paper, in comparison to EDTA plasma, was 107% (SD 8.1%; n =6) over a range from 2.4 to 34.5μg/L. Linear regression analysis ( n =119) showed a correlation of R 2 =0.97 for the hGH concentration in serum and on filter paper samples. Conclusion Our findings demonstrate the reliability of measurements of hGH in dried blood spots on filter paper. The advantages of this method are the low sample volume and the easy transport, storage, and handling of samples. This method contributes to the standardisation of diagnostics pertaining to abnormal hGH secretion as it facilitates the comparison of decisive measurements.
Sepiapterin Treatment in Atherosclerosis

Tetrahydrobiopterin (BH4) plays an important role in functional and metabolic cellular homeostasis, with additional effects on proliferation.,1,2⇓ immune responsiveness,3,4⇓ and neuronal activity.5–7⇓⇓ Mutations in either de novo biosynthetic or regeneration (salvage) pathways result in BH4 deficiency associated with diminished levels of seratonin and dopamine with progressive neurologic symptoms.8,9⇓ The phenotypic presentation of these synthetic mutations can be predicted in large part by the role of BH4 as an obligatory cofactor in phenylalanine, tryptophan, and tyrosine hydroxylases (the rate-limiting enzymes for catecholamine and seratonin synthesis). The function of BH4 in these aromatic amino acid hydroxylases involves redox-active donation of electrons and reductive enzyme activation and is associated with a tightly coupled system for regeneration of BH4 from the oxidized dihydrobiopterin.8,10⇓ See page 1655 In addition to its role in the biosynthesis of monoamine neurotransmitters, BH4 serves as an essential cofactor in all isoforms of nitric oxide synthases (NOS), with the Km for BH4 for NOS several orders of magnitude lower than for the aromatic amino acid hydroxylases: NOS, ≈0.3 μmol/L vs ≈3 μmol/L for phenylalanine hydroxylase, ≈30 μmol/L for tyrosine hydroxylase and tryptophan hydroxylase, suggesting tight coupling of the cofactor with enzyme.8 However, the precise function(s) of BH4 in NOS enzymatic activity is not as well defined as in the aromatic amino acid hydroxylase enzymes and may vary according to enzyme isoform. For endothelial NOS (eNOS), BH4 has been reported to …