cssi/SciSciGPT-SciSciNet huggingface dataset:
Microbial ribulose 1,5-bisphosphate carboxylase/oxygenase: A different perspective

Marine and terrestrial photosynthetic and chemoautotrophic microorganisms assimilate considerable amounts of carbon dioxide. Like green plastids, the predominant means by which this process occurs is via the Calvin-Benson-Bassham reductive pentose phosphate pathway, where ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) plays a paramount role. Recent findings indicate that this enzyme is subject to diverse means of control, including specific and elaborate means to guarantee its high rate and extent of synthesis. In addition, powerful and specific means to regulate Rubisco activity is a characteristic feature of many microbial systems. In many respects, the diverse properties of microbial Rubisco enzymes suggest interesting strategies to elucidate the molecular basis of CO2/O2 specificity, the ‘holy grail’ of Rubisco biochemistry. These systems thus provide, as the title suggests, ‘different perspectives’ to this fundamental problem. These include vast possibilities for imaginative biological selection using metabolically versatile organisms with well-defined genetic transfer capabilities to solve important issues of Rubisco specificity and molecular control. This review considers the major issues of Rubisco biochemistry and regulation in photosynthetic microoganisms including proteobacteria, cyanobacteria, marine nongreen algae, as well as other interesting prokaryotic and eukaryotic microbial systems recently shown to possess this enzyme.
X-Ray Measurement of Material Properties in Composites

Advanced materials for use in the aerospace industry are presently being developed and applied at an astonishing rate. This pace is driven by the need for materials that can withstand higher operating temperatures and loads, yet remain cost competitive. As the performance demands of aerospace materials push nearer and nearer the theoretical limit for strength, the allowed flaw size in traditional materials is driven smaller, making quality control more stringent. This demand for improved performance characteristics is also generating strong interest in other materials such as: exotic alloys, ceramics and reinforced composites. A need exists for characterizing these advanced materials for composition variations, flaw content, inclusions and porosity using nondestructive techniques at all stages of the materials life cycle. These stages include initial characterization of a new material, process control during the manufacturing of the material, quality control of incoming material, and the in service inspection of the final part.
Organic Compound Concentrations of Size-Segregated PM10 during Sugarcane Burning and Growing Seasons at a Rural and an Urban Site in Florida, USA

ABSTRACTFlorida has the most land used to grow sugarcane crops in the United States. The preharvest sugarcane leaf burning elevates ambient particle matter (PM) concentrations in rural areas with dominant sugarcane agriculture (Belle Glade) and affects the air quality of coastal urban sites (Delray Beach). In this study, ambient particles segregated by size were analyzed to identify trace organic compounds from PM sources that may cause adverse health effects. The sampling campaign was conducted simultaneously at urban and rural sites, and revealed that the organic compound concentration of each particle size varies significantly between the sugarcane burning season (SBS) in January and sugarcane growing season (SGS) in May. The results indicated that PM3 contains at least 76% of the organic compound concentrations detected in the samples collected from both sites and during both seasons. The concentrations of trace organic compounds were higher in the SBS than in the SGS. Combustion-oriented hopanes, polycyclic aromatic hydrocarbons (PAHs), and oxygenated PAHs were mainly detected in PM0.49. The detection of elevated levoglucosan concentrations at the urban site indicates that fine particles generated from biomass burning traveled from the rural site to the urban site. Secondary organic compounds such as dicarboxylic acids, phytol, and 6,10,14-trimethyl-2-pentadecanone exhibited similar concentration patterns in the rural and urban sites during both seasons. In the SGS, PM10 concentrations at both sites were extremely similar; however, the organic compound levels were lower at the rural site than at the urban site in the SBS. This result should be investigated further by researchers investigating the health aspects of organic compound concentrations.
Distributed Computing Trade-offs with Random Connectivity

Trade-offs between distributed computation and communication are recently attracting significant interest; however, these works assume that all nodes that share the distributed computation task are within the same broadcast domain, and each can losslessly broadcast to every other node that takes part in the computation task. In this work, we dispose of this assumption, and consider the case where each node can broadcast to a subset of the nodes that take part in the computation task. We model the network via an Erdos-Renyi random graph model where a pair of nodes can communicate with each other with a probability p. We propose both uncoded and coded transmission schemes and give an achievable communication-computation tradeoff for large computational loads.
Learning and pricing models for repeated generalized second-price auction in search advertising

Abstract In search advertising how much an advertiser is willing to pay for a click or tap on his search ad is private information, which hampers an ad seller’s ability to set the best reserve price to increase the revenue for the generalized second-price (GSP) auctions used to allocate ad slots. We present a series of learning and pricing models for repeated GSP auctions selling multiple heterogeneous items. This paper contributes to the literature in dynamic pricing with learning and complements the existing off-line studies on impact of the reserve price in the multi-billion dollar online advertising business. With few restrictions on the distribution function of the unknown parameter, algorithms are developed to estimate the empirical distribution function and determine the best reserve price to reduce the revenue loss (regret) over time. When bidders bid in the locally envy-free equilibrium, we present an algorithm that has the best attainable regret upper bound. When bidders do not bid in the locally envy-free equilibrium, we propose a GSP auction with position-specific reserve prices and develop an algorithm with the same regret bound to mitigate the risk of strategic bidding. With a high volatility involved, learning becomes more active while earning is more effective. When bidders coordinate bidding, the properly selected starting reserve prices can substantially reduce the revenue loss from possible collusive bidding behaviors.
(Re)directing a university storytelling troupe for at-risk elementary students for course credit: a story of embodied empathy, literacy, and personal transformation

This essay maps a professor/director's experience designing and leading a university storytelling troupe that performs for children in local Title 1 elementary schools for course credit. The direct...
Addressing Critiques of the Proposed CMS Metric of Organ Procurement Organ Performance: More Data Isn't Better.

BACKGROUND Centers for Medicare and Medicaid Services (CMS) has proposed a rule change to redefine the metric by which organ procurement organizations (OPOs) are evaluated. The metric relies on Centers for Disease Control and Prevention (CDC) data on inpatient deaths from causes consistent with donation among patients <75 years of age. Concerns have been raised that this metric does not account for rates of ventilation, and prevalence of cancer and severe sepsis, without objective data to substantiate or refute such concerns. METHODS We estimated OPO-level donation rates using CDC data, and used Agency for Healthcare Research and Quality/Healthcare Cost and Utilization Project data from 43 State Inpatient Databases to calculate "adjusted" donation rates. RESULTS The CMS metric and the ventilation-adjusted CMS metric were highly concordant in absolute terms (Spearman and Pearson correlation coefficients ≥0.95). In the Bland-Altman plot, 100% (48/48) of paired values (standard deviations [SDs] of the CMS and "ventilation adjusted" metrics) were within 1.96 SDs of the mean difference, with near-perfect correlation in Passing and Bablok regression (Lin's concordance correlation coefficient: 0.97). The CMS metric and the ventilation/cancer/sepsis-adjusted metric were highly concordant in absolute terms (Spearman and Pearson correlation coefficients ≥0.94). In the Bland-Altman plot, 97.9% (47/48) of paired values (SDs of the CMS and "ventilation/cancer/sepsis adjusted" metrics) were within 1.96 SDs of the mean difference, with near-perfect correlation in the Passing and Bablok regression (Lin's concordance correlation coefficient: 0.97). CONCLUSIONS These conclusions should provide CMS, and the transplant community, with comfort that the proposed CMS metric using CDC inpatient death data as a tool to compare OPO is not compromised by its lack of inclusion of ventilation or other comorbidity data.
Pharmacodynamic Correlates of Linezolid Activity and Toxicity in Murine Models of Tuberculosis

Author(s): Bigelow, Kristina M; Deitchman, Amelia N; Li, Si-Yang; Barnes-Boyle, Kala; Tyagi, Sandeep; Soni, Heena; Dooley, Kelly E; Savic, Rada M; Nuermberger, Eric L | Abstract: BackgroundLinezolid (LZD) is bactericidal against Mycobacterium tuberculosis, but it has treatment-limiting toxicities. A better understanding of exposure-response relationships governing LZD efficacy and toxicity will inform dosing strategies. Because in vitro monotherapy studies yielded conflicting results, we explored LZD pharmacokinetic/pharmacodynamic (PK/PD) relationships in vivo against actively and nonactively multiplying bacteria, including in combination with pretomanid.MethodsLinezolid multidose pharmacokinetics were modeled in mice. Dose-fractionation studies were performed in acute (net bacterial growth) and chronic (no net growth) infection models. In acute models, LZD was administered alone or with bacteriostatic or bactericidal pretomanid doses. Correlations between PK/PD parameters and lung colony-forming units (CFUs) and complete blood counts were assessed.ResultsOverall, time above minimum inhibitory concentration (TgMIC) correlated best with CFU decline. However, in growth-constrained models (ie, chronic infection, coadministration with pretomanid 50 mg/kg per day), area under the concentration-time curve over MIC (AUC/MIC) had similar explanatory power. Red blood cell counts correlated strongly with LZD minimum concentration (Cmin).ConclusionsAlthough TgMIC was the most consistent correlate of efficacy, AUC/MIC was equally predictive when bacterial multiplication was constrained by host immunity or pretomanid. In effective combination regimens, administering the same total LZD dose less frequently may be equally effective and cause less Cmin-dependent toxicity.
Improvement in Back Pain Following Abdominoplasty: Results of a 10-Year, Single-Surgeon Series.

BACKGROUND Few studies have examined the impact of abdominoplasty on chronic back pain. OBJECTIVES The aim of this study was to test our hypothesis that patients undergoing abdominoplasty with anterior abdominal wall plication will show significant improvements in back pain and physical function compared with those without plication. METHODS We utilized Current Procedural Terminology (CPT) codes to identify patients who underwent abdominoplasty with the senior author over a 10-year period. The Oswestry Disability Index (ODI) and the RAND 36-Item Short-Form Health Survey (SF-36) were administered. All patients indicating preoperative back pain were reviewed. RESULTS Of 338 patients, 143 surveys (42.3%) were returned; 51 patients (35.7%; n = 28 aesthetic, n = 23 massive weight loss) reported preoperative back pain on the ODI. Paired t tests compared overall and strata-specific changes in ODI and SF-36 pre- and postsurgery. Multivariable linear regression models were fitted to model relations between scores and plication, adjusting for presurgery scores and patient variables. There were significant improvements in overall patient cohort in ODI (-15.14), SF-36 physical function (19.92), and pain (17.42) (P < 0.001), as well as when patients were stratified by plication status. However, outcomes between those with plication and those without were not significantly different. CONCLUSIONS Abdominoplasty with and without anterior abdominal wall plication significantly improves ODI and SF-36 scores relating to physical function and pain, in both aesthetic and massive weight loss patients. Outcomes did not differ based on plication status. All patients with preoperative back pain showed improvement regardless of operation performed, suggesting that abdominoplasty with or without abdominal wall plication improves chronic back pain in this patient population. LEVEL OF EVIDENCE: 4
Traveling Wave Line Selection Method Based on Multi-terminal Information Fusion and Artificial Neural Network

The existing line selection methods are affected by complex fault characteristics, such as transition resistance, line parameters and other factors, the accuracy is not high. The traveling wave line selection protection method is not affected by the grounding mode and the above factors. A traveling wave fault line selection method based on artificial intelligence and multi-terminal information fusion is proposed. The grounding fault traveling wave selection method chooses zero- mode voltage traveling wave as the basis of time detection. The classified relative fault time array samples are obtained through fault simulation, which are input into the neural network for training. And then, the result of line selection can be obtained by inputting the unclassified samples into the network. The simulation results show that the line selection method is feasible.
Host-Pathogen Interaction as a Novel Target for Host-Directed Therapies in Tuberculosis

Tuberculosis (TB) has been a transmittable human disease for many thousands of years, and M. tuberculosis is again the number one cause of death worldwide due to a single infectious agent. The intense 6- to 10-month process of multi-drug treatment, combined with the adverse side effects that can run the spectrum from gastrointestinal disturbances to liver toxicity or peripheral neuropathy are major obstacles to patient compliance and therapy completion. The consequent increase in multidrug resistant TB (MDR-TB) and extensively drug resistant TB (XDR-TB) cases requires that we increase our arsenal of effective drugs, particularly novel therapeutic approaches. Over the millennia, host and pathogen have evolved mechanisms and relationships that greatly influence the outcome of infection. Understanding these evolutionary interactions and their impact on bacterial clearance or host pathology will lead the way toward rational development of new therapeutics that favor enhancing a host protective response. These host-directed therapies have recently demonstrated promising results against M. tuberculosis, adding to the effectiveness of currently available anti-mycobacterial drugs that directly kill the organism or slow mycobacterial replication. Here we review the host-pathogen interactions during M. tuberculosis infection, describe how M. tuberculosis bacilli modulate and evade the host immune system, and discuss the currently available host-directed therapies that target these bacterial factors. Rather than provide an exhaustive description of M. tuberculosis virulence factors, which falls outside the scope of this review, we will instead focus on the host-pathogen interactions that lead to increased bacterial growth or host immune evasion, and that can be modulated by existing host-directed therapies.
Nondiagonal anisotropic quantum Hall states

Using the coupled wire construction, the authors investigate a novel Abelian quantum Hall state that possesses a symmetry-enriched topological order given a combination of internal and spatial symmetry. This is termed the ``nondiagonal'' state due to its relation to nondiagonal conformal field theory, and is characterized by quasiparticles with constrained motion, whose braiding statistics features a marriage of Laughlin state and \ensuremath{\mathbb{Z}}${}_{p}$ toric code. Dislocations in the wire model act as twist defects that implement the $\mathbf{e}\ensuremath{\leftrightarrow}\mathbf{m}$ anyonic symmetry.
Zero-Inflated gaussian mixed models for analyzing longitudinal microbiome data.

Motivation The human microbiome is variable and dynamic in nature. Longitudinal studies could explain the mechanisms in maintaining the microbiome in health or causing dysbiosis in disease. However, it remains challenging to properly analyze the longitudinal microbiome data from either 16S rRNA or metagenome shotgun sequencing studies, output as proportions or counts. Most microbiome data are sparse, requiring statistical models to handle zero-inflation. Moreover, longitudinal design induces correlation among the samples and thus further complicates the analysis and interpretation of the microbiome data. Results In this article, we propose zero-inflated Gaussian mixed models (ZIGMMs) to analyze longitudinal microbiome data. ZIGMMs is a robust and flexible method which can be applicable for longitudinal microbiome proportion data or count data generated with either 16S rRNA or shotgun sequencing technologies. It can include various types of fixed effects and random effects and account for various within-subject correlation structures, and can effectively handle zero-inflation. We developed an efficient Expectation-Maximization (EM) algorithm to fit the ZIGMMs by taking advantage of the standard procedure for fitting linear mixed models. We demonstrate the computational efficiency of our EM algorithm by comparing with two other zero-inflated methods. We show that ZIGMMs outperform the previously used linear mixed models (LMMs), negative binomial mixed models (NBMMs) and zero-inflated Beta regression mixed model (ZIBR) in detecting associated effects in longitudinal microbiome data through extensive simulations. We also apply our method to two public longitudinal microbiome datasets and compare with LMMs and NBMMs in detecting dynamic effects of associated taxa.
Variation in visual sensitivity predicts motion sickness in virtual reality

Abstract Motion sickness varies across observers. While some experience immediate and severe symptoms, others seem relatively immune. Multiple explanations have been advanced. Some argue that conflicting cues provided by the visual and vestibular systems are the underlying cause. Others claim postural sway, which differs between the sexes, can explain previously-reported motion sickness susceptibility differences. We used virtual reality to test these accounts. We found that an observer’s visual sensitivity to motion parallax predicted susceptibility, but found little evidence for differences based on sex (N = 95; 59 females, 36 males). Furthermore, our results suggest that sex differences are likely due to poor personalization of VR displays, which default to male settings and introduce cue conflicts for the majority of females. These results suggest that the probability of detecting cue conflicts is limited by an observer’s sensitivity to specific sensory cues and thus identify a cause for differences in motion sickness severity.
The time is now to improve the treatment of biodiversity in Canadian environmental impact statements

Abstract Global biodiversity loss is among the pressing environmental challenges facing the planet in the 21st century. Environmental impact assessment (EIA) offers one possible means to address some of the drivers of biodiversity loss, yet research over the past 20 years has shown that the treatment of biodiversity within EIA is often insufficient. This review addresses how well biodiversity has been treated in the environmental impact statements (EISs) for 14 projects conducted under the federal Canadian Environmental Assessment Act or its 2012 successor (CEAA2012). The selected projects commenced between 2005 and 2014, cover most Canadian provinces, and include a range of project types. A biodiversity assessment index (BAI) is calculated to assess the information quality of EISs with respect to biodiversity, scoring projects from zero to one based on 49 review criteria. Results are discussed for each stage of the EIA process. Average BAI for the 14 projects was just below 0.5, indicating many substantial deficiencies regarding the inclusion of biodiversity. The BAI between projects conducted under the two Acts did not differ significantly, while project footprint, EIS page-length, and the page-length of biodiversity-related chapters were all positively related with BAI. Some common problems in these EISs included not defining ecologically relevant study areas, poor consideration of alternatives with respect to biodiversity impacts, limited description of the methods for comparing alternatives, impact assessments and analysis, mitigation and monitoring, and a lack of information on the likely success of mitigation, among others. Recommendations for improving the poor treatment of biodiversity in EISs are provided and include, inter alia, setting clear requirements regarding minimum survey efforts, implementing measurable targets or thresholds for important biodiversity features, and adopting regional-EIA to improve the treatment of cumulative effects. Improving the quality of biodiversity considerations in EISs will be important if EIA is to play a role in meeting the measurable outcome-based conservation targets envisioned for the post-2020 global biodiversity framework.
Optimizing Operational Strategies for Mass Transit Systems in Response to a Global Pandemic

This study analyzes the risk involved in riding various transit modes during and after a global pandemic. The goal is to identify which factors are related to this risk, how such a relationship can be represented in a manner amenable to analysis, and what a transit operator can do to mitigate the risk while running its service as efficiently as possible. The resulted infection risk model is sensitive to such factors as prevalence of infection, baseline transmission probability, social distance, and expected number of human contacts. Built on this model, we formulate, analyze and test three versions of a transit operator’s design problem. In the first, the operator seeks to jointly optimize vehicle capacity and staff testing frequency while keeping the original service schedule and satisfying the infection risk requirement. The second model assumes the operator is obligated to meet the returning demand after the peak of the pandemic. The third allows the operator to run more than one transit line and to allocate limited resources between the lines, subject to the penalty of unserved passengers. We find: (i) The optimal profit, as well as the testing frequency and the vehicle capacity, decreases when passengers expect to come in close contact with more fellow riders in a trip; (ii) Using a larger bus and/or reducing the testing cost enables the operator to both test drivers more frequently and allow more passengers in each bus; (iii) If passengers weigh the risk of riding bus relative to taxi, a higher prevalence of infection has a negative effect on transit operation, whereas a higher basic transmission probability has a positive effect; (iv) The benefit of improving service capacity and/or testing more frequently is limited given the safety requirement imposed. When the demand rises beyond the range of the capacity needed to maintain sufficient social distancing, the operator has no choice but to increase the service frequency; and (v) In the multi-line case, the lines that have a larger pre-pandemic demand, a higher penalty for each unserved passenger, or a greater exposure risk should be prioritized.
A new efficient fully-decoupled and second-order time-accurate scheme for Cahn─Hilliard phase-field model of three-phase incompressible flow

Abstract For the highly coupled and nonlinear Cahn–Hilliard phase-field model of three-phase incompressible flow, how to establish a fully-decoupled numerical scheme with second-order time accuracy has always been a very difficult and unsolved problem. In this paper, we propose a novel decoupling method, which only needs to solve several decoupling linear elliptic equations with constant coefficients at each time step to obtain a numerical solution with second-order time accuracy. The key idea is to introduce two nonlocal auxiliary variables into the system, one of which is used to linearize the nonlinear potential, and the other is used to introduce an ordinary differential equation to deal with the nonlinear coupling terms with “zero-energy-contribution” characteristics. We strictly prove the solvability and unconditional energy stability of the scheme, and conduct numerical simulations in 2D and 3D to show the accuracy and stability of the scheme numerically. To the best of the author’s knowledge, the method developed in this paper is the first second-order fully-decoupled scheme for the hydrodynamics coupled phase-field model.
Life with habit and expectation: A new explanation of equity premium puzzle

Previous writers have attempted to resolve the equity premium puzzle by employing a utility function that depends on current consumption minus (or relative to) past habit consumption. This paper points out that an individual's current utility may also depend upon how well off in the recent past he or she had expected to be today. Hence we add the concept “expectation formation” to the utility modification term in a model with a habit‐formation utility function. We apply the model to the equity premium puzzle and find that it is able to fit the data with a relatively low coefficient of relative risk aversion. Furthermore, we introduce an updated data sample and apply different values of discounting factors, and find that in all circumstances, the model is able to generate coefficients of risk aversion that are consistent with theory. Hence we conclude that the model is able to resolve the equity premium puzzle.
Fairy rings, associated fungi, and assessment of their distribution across environmental variables using GIS

Abstract Fairy rings are conspicuous features of the Laramie Basin of southeastern Wyoming. Ten fairy ring sites chosen for intensive study were located using a small plane and 415 whole and partial fairy rings were georeferenced and ground-truthed. Fairy ring forming fungi were identified using a combination of taxonomy and ITS fungal barcode sequence comparisons. Precipitation, vegetation, soil type, elevation, slope, and slope aspect were queried using GIS. Eight fairy ring forming species were identified from the sites, including three unknown species, and two taxa not previously reported to form fairy rings. Most fairy rings occurred in drier mixed-grass prairie vegetation, whereas a small percentage occurred in mesic shrub dominated riparian vegetation. Most fungal species exhibited preferences for elevation and slope aspect, and rings were scarce on east facing slopes. The identity and autecology of individual fairy ring fungi and importance of environmental variables to fairy ring biology is discussed.
Role of YAP in early ectodermal specification and a Huntington’s Disease model of human neurulation

Abstract The Hippo pathway, a highly conserved signaling cascade that functions as an integrator of molecular signals and biophysical states, ultimately impinges upon the transcription coactivator Yes-associated protein 1 (YAP). Hippo-YAP signaling has been shown to play key roles both at the early embryonic stages of implantation and gastrulation, and later during neurogenesis. To explore YAP’s potential role in neurulation, we used self-organizing neuruloids grown from human embryonic stem cells on micropatterned substrates. We identified YAP activation as a key lineage determinant, first between neuronal ectoderm and non-neuronal ectoderm, and later between epidermis and neural crest, indicating that YAP activity can enhance the effect of BMP4 stimulation and therefore affect ectodermal specification at this developmental stage. Because aberrant Hippo-YAP signaling has been implicated in the pathology of Huntington’s Disease (HD), we used isogenic mutant neuruloids to explore the relationship between signaling and the disease. We found that HD neuruloids demonstrate ectopic activation of gene targets of YAP and that pharmacological reduction of YAP’s transcriptional activity can partially rescue the HD phenotype.
Efforts to Recruit Medical Students From Rural Counties: A Model to Evaluate Recruitment Efforts.

Background Over the past 40 years, the physician supply of North Carolina (NC) grew faster than the total population. However, the distribution of physicians between urban and rural areas increased, with many more physicians in urban areas. In rural counties, access to care and health disparities remain concerning. As a result, the medical school implemented pipeline programs to recruit more rural students. This study investigates the results of these recruitment efforts. Methodology Descriptive analyses were conducted to compare the number and percentage of rural and urban students from NC who applied, interviewed, and were accepted to the University of North Carolina's School of Medicine (UNC SOM). The likely pool of rural applicants was based on the number of college-educated 18-34-year-olds by county. Results Roughly 10.9% of NC's population of college-educated 18-34-year-olds live in rural counties. Between 2017 and 2019, 9.3% (n = 225) of UNC SOM applicants were from a rural county. An increase of just 14 additional rural applicants annually would bring the proportion of rural UNC SOM applicants in alignment with the potential applicant pool in rural NC counties. Conclusions Our model of analysis successfully calculated the impact of recruitment efforts to achieve proportional parity in the medical school class with the rural population of the state. Addressing rural physician workforce needs will require multiple strategies that affect different parts of the medical education and healthcare systems, including boosting college completion rates in rural areas. This model of analysis can also be applied to other pipeline programs to document the success of the recruitment efforts.
Music reading expertise affects visual change detection: Evidence from a music-related flicker paradigm.

To study the mechanisms and boundary conditions of expertise effects on change detection, we introduced a novel music-related variant of the flicker paradigm. Specifically, we monitored the eye movements of expert musicians (with 10 years of music experience) and non-musicians (who could not read music) while they located changes across two rapidly alternating versions of a music score, with a blank screen presented between each screen change. Relative to the non-musicians, experts were faster at change detection, with shorter fixations and larger saccade amplitudes. Expertise effects on accuracy and saccade amplitude were magnified for visually complex relative to simple music scores. Consistent with the assumptions of chunking and template theories of expertise, our results suggest that expert musicians can use chunking (i.e., perceptual grouping) mechanisms to facilitate perceptual encoding during change detection.
Strategies for the Retention of Undergraduate Hospitality Students

(1993). Strategies for the Retention of Undergraduate Hospitality Students. Hospitality & Tourism Educator: Vol. 5, No. 4, pp. 71-78.
Never-ending struggles with mid-spatial frequencies

Optical surfaces feature a wide range of length scales from “figure” down to “finish”, but the mid-spatial frequency structure (MSF) holds growing significance. Cost-effective production of systems demands answers to multiple layers of related questions, such as how best to quantify MSF, assess its optical impact, and employ existing production tools to meet MSF requirements. These answers evolve as new production technologies are introduced. I present general observations about a few of the associated challenges and attempt to clarify some essential aspects related to quantifying MSF as well as estimating its impact.
Structure of the Janus-faced C2B domain of rabphilin.

C2 domains are widespread protein modules that often occur as tandem repeats in many membrane-trafficking proteins such as synaptotagmin and rabphilin. The first and second C2 domains (C2A and C2B, respectively) have a high degree of homology but also specific differences. The structure of the C2A domain of synaptotagmin I has been extensively studied but little is known about the C2B domains. We have used NMR spectroscopy to determine the solution structure of the C2B domain of rabphilin. The overall structure of the C2B domain is very similar to that of other C2 domains, with a rigid β-sandwich core and loops at the top (where Ca2+ binds) and the bottom. Surprisingly, a relatively long α-helix is inserted at the bottom of the domain and is conserved in all C2B domains. Our results, together with the Ca2+-independent interactions observed for C2B domains, indicate that these domains have a Janus-faced nature, with a Ca2+-binding top surface and a Ca2+-independent bottom surface.
Generation and characterization of micron and sub-micron particulate using an electrothermal source

Summary form only given. The Surface Interaction Research Experiment at N.C. State (SIRENS) produces a pulsed (/spl sim/100 ms), low temperature (0.1- 3 eV), high density (10/sup 13/-10/sup 19/ cm/sup -3/), flowing plasma by ablating a liner material. As the plasma expands and cools, micron and sub-micron particles develop from the liner material. This study examines the size of the particulate generated and the associated plasma parameters for copper, aluminum, copper-aluminum, and polycarbonate liner materials at several locations downstream from the source for a 5.8 kJ input energy. The plasma is characterized using optical emission spectroscopy under the LTE assumption and Stark broadening of the H/sub /spl alpha// line and neutral copper lines, which are always present in the source. All linear materials produce a plasma with an electron temperature on the order of 0.5 eV with a range of electron densities between 10/sup 16/ and 10/sup 18/ cm/sup -3/ at all the downstream locations. The particulate was collected on a series of copper, stainless steel, woven, or non-woven fabric substrates for analysis. copper particulates collected on woven fabric. All the substrates showed spherical particles, but the metallic substrates showed evidence of short fibers developed from the liner material. The particles are characterized by scanning electron microscopy coupled to software capable of calculating particles' sizes. The analysis shows a range of particle sizes from 0.1 micron to 10 micron. By using EDX analysis, the composition of the droplets was determined. The composite copper-aluminium liner produces particles composed of both copper and aluminum without a visible separation of the materials.
Between monks: tales of monastic companionship in early Byzantium.

The Latin version of John Moschos's Spiritual Meadow preserves a story narrated to John and his companion Sophronios by Abba Stephen the Cappadocian while they visited Mount Sinai. Stephen was in church on the Thursday of Holy Week, the feast of the Lord's Supper, when in his words "as the holy sacrifice was being offered and all the fathers were present, I looked and saw two anchorites enter the church. They were naked, yet none of the other fathers perceived that they were naked except me." After communion, as the two monastic brothers left the church, Stephen followed them and begged them to take him with them. They refused, saying, "It is not possible for you to be with us; stay here; this is the place for you." The men offered prayer on his behalf, and then in Stephen's words, "before my eyes, they went onto the water of the Red Sea on foot and departed across the sea."1
Signalling through the lipid products of phosphoinositide-3-OH kinase

When a stimulatory agonist molecule binds at the exterior of the cell membrane, a second messenger transduces the signal to the interior of the cell. Second messengers can be derived from phospholipids in the membrane by the action of the enzymes phospholipase C or phosphoinositide-3-OH kinase (PI(3)K). PI(3)K is a key player in many cellular responses, including the movement of organelle membranes, shape alteration through rearrangement of cytoskeletal actin, transformation and chemotaxis. But how PI(3)K mediates these responses is only now becoming clear.
CCR5-Mediated Human Immunodeficiency Virus Entry Depends on an Amino-Terminal gp120-Binding Site and on the Conformational Integrity of All Four Extracellular Domains

The human immunodeficiency virus type 1 coreceptor activity of CCR5 depends on certain polar and charged residues in its amino-terminal domain. Since studies of chimeric receptors have indicated that the extracellular loops of CCR5 are also involved in viral fusion and entry, we have explored the role of bulky, polar and nonpolar residues in these regions. Selected amino acids in the three extracellular loops were individually changed to alanines, and the coreceptor activities of the mutant CCR5 proteins were tested in a luciferase reporter virus-based entry assay. We found that the cysteines in the extracellular loops of CCR5 are essential for coreceptor activity. However, only minor (two- to threefold) effects on coreceptor function were noted for all of the other alanine substitutions. We also demonstrated that when the first 19 residues of the amino-terminal region were separated from the rest of CCR5, by insertion of glycine/serine spacers between proline 19 and cysteine 20, coreceptor function decreased. Together with our previous studies, these data indicate that both an amino-terminal gp120-binding site and extracellular domain geometry play a role in viral entry.
Hemodynamics in patients with severe toxemia during labor and delivery

Abstract Three patients with severe pre-eclampsia-toxemia were studied with thermodilution tip pulmonary artery catheters. All patients were delivered by cesarean section with general anesthesia and endotracheal intubation. The left ventricular stroke work indices (LVSWI) of these patients were higher than those of normal nonpregnant subjects. There was no evidence of myocardial depression in terms of either cardiac index or the LVSWI-pulmonary capillary wedge pressure (Frank-Starling) relationship. Pulmonary arteriolar resistance (PAR) was found to be within or below the normal nonpregnant range, suggesting that in severe toxemia the pulmonary vasculature is not involved in a primary vasospastic process. At delivery a rise in cardiac index (CI) and mean pulmonary capillary wedge pressure ( PCWP) occurred. The PCWP was higher in the postpartum period than prior to delivery. This was felt to represent an increase in circulating blood volume. The therapeutic significance of these findings is discussed.
Endoscopic Nd: YAG Laser Therapy as Palliative Treatment for Advanced Adenocarcinoma of the Gastric Cardia

Abstract Fifteen patients with advanced adenocarcinoma of the gastric cardia were treated with endoscopic neodymium: yttrium aluminum garnet laser therapy. Four patients developed recurrence after previous surgery. In 7 patients, a decision was made at exploration that a palliative operation was not feasible. In the remaining 4 patients, surgery was not considered because of widespread disease or the patient's condition. Fourteen of fifteen were classified as stage IV (tumor, node, metastasis). Tumors ranged in length from 3 to 10 cm (mean 6.3). Luminal opening was 4 mm or less in 12 patients. The mean number of treatments required to alleviate symptoms and remove obstruction was 2.8 (range 1–5) and the mean number of days required was 5.7 (range 1–12). An average of 6129 W/s were given per treatment and the mean total energy was 17,570 W/s. Luminal diameter at the narrowest segment increased from 3.3 mm before treatment to 12.1 mm after treatment. Clinical benefit in terms of increased food intake was demonstrated in all patients. No major complications directly attributable to laser therapy were seen. The overall results are encouraging and hold promise for a patient population in whom the therapeutic options are generally very limited.
Combined Flexor-Pronator Mass and Ulnar Collateral Ligament Injuries

The anterior bundle of the ulnar collateral ligament (UCL) is the primary stabilizer against valgus stress in the elbow. However, when the UCL is compromised, the flexor-pronator mass becomes the primary dynamic valgus stabilizer of the elbow. Combined UCL and flexor-pronator mass injuries are a subset of medial elbow injuries sustained by overhead throwing athletes. Compared to athletes who suffer isolated UCL injuries, the group with combined UCL and flexor-pronator mass injuries tend to be older and have worse outcomes after surgical reconstruction. There are few studies describing these injuries in the orthopedic literature, and it is unclear what causes them to fail surgical management at a higher rate than UCL injuries alone. Treatment of this group requires a thorough history and physical exam, as well as a magnetic resonance imaging (MRI) for surgical planning. Based on the amount of flexor-pronator mass injury, different operative approaches may be warranted. It is important to counsel these patients about their prognosis, especially elite baseball players regarding their chances of returning to their previous level of play.
Power output of sound-producing muscles in the tree frogs Hyla versicolor and Hyla chrysoscelis.

Sound-producing muscles provide the opportunity of studying the limits of power production at high contractile frequencies. We used the work loop technique to determine the power available from the external oblique muscles in two related species of North American gray tree frog, Hyla chrysoscelis and Hyla versicolor. These trunk muscles contract cyclically, powering high-intensity sound production in anuran amphibians. The external oblique muscles in H. chrysoscelis have an in vivo operating frequency of 40–55 Hz at 20–25 degrees C, whereas in H. versicolor these muscles contract with a frequency of 20–25 Hz at these temperatures. In vivo investigations have shown that these muscles use an asymmetrical sawtooth length trajectory (with a longer shortening phase compared with the lengthening phase) during natural cycles. To study the influence of this particular length trajectory on power output, we subjected the muscles to both sinusoidal and sawtooth length trajectories. In both species, the sawtooth trajectory yielded a significantly higher power output than the sinusoidal length pattern. The maximum power output during sawtooth cycles was similar in both species (54 W kg(−)(1) in H. chrysoscelis and 58 W kg(−)(1) in H. versicolor). These values are impressive, particularly at the operating frequencies and temperatures of the muscle. The sinusoidal length trajectory yielded only 60 % of the total power output compared with the sawtooth trajectory (34 W kg(−)(1) for H. chrysoscelis and 36 W kg(−)(1) for H. versicolor). The optimum cycle frequencies maximizing the power output using a sawtooth length pattern were approximately 44 Hz for H. chrysoscelis and 21 Hz for H. versicolor. These frequencies are close to those used by the two species during calling. Operating at higher frequencies, H. chrysoscelis maximized power at a strain amplitude of only 8 % compared with a value of 12 % in H. versicolor. These strains match those used in vivo during calling. The stimulus timing observed in vivo during calling was also similar to that yielding maximum power at optimal frequency in both species (6 ms and 8 ms before the start of shortening in H. chrysoscelis and H. versicolor, respectively). As expected, twitch duration in H. chrysoscelis is much shorter than that in H. versicolor (23 ms and 37 ms, respectively). There was a less remarkable difference between their maximum shortening velocities (V(max)) of 13.6 L(0)s(−)(1) in H. chrysoscelis and 11.1 L(0)s(−)(1) in H. versicolor, where L(0) is muscle length. The force-velocity curves are very flat, which increases power output. At the myofibrillar level, the flat force-velocity curves more than compensate for the lower peak isometric force found in these muscles. The data presented here emphasize the importance of incorporating in vivo variables in designing in vitro studies.
FDTD calculation of the spontaneous emission coupling factor in optical microcavities

We present the detailed analysis of the spontaneous emission coupling factor (β factor) of the micro cavity based on a 2D photonic crystal in an optically thin dielectric slab. We investigate the maximum β value that can be achieved with this micro cavity and discuss its dependence on the quantum well position, as well as on the pumping area diameter. The analysis is performed using the general method for the β factor calculation that we developed. The method is based on the classical model for atomic transitions in a semiconductor active medium. Finite difference time domain method is used to solve the electromagnetic fields of the system and calculate the total radiated energy, as well as the energy radiated into the mode of interest.
Anaerobic, glycogen-dependent transport of amino acids by the placenta.

THE concentration of amino acids is greater in foetal than in maternal blood and their placental transport is fairly well established to depend on energy dependent processes1. Although it is reported that placental transport of amino acids occurs only in aerobic conditions2–4, we show here that the human placenta can accumulate amino acids anaerobically against a concentration gradient, and that this is sustained by the utilization of glycogen.
The role of males in the stimulation of reproductive function in female cotton-top tamarins, Saguinus o. oedipus

Abstract When mature female cotton-top tamarins are removed from the reproductive suppression of their mother, reproductive hormone levels and scent-marking behaviour increase, but the females do not ovulate until paired with an unfamiliar male. This study determined the effects of exposure to male urine and direct contact with both familiar and unfamiliar males on sociosexual behaviour and urinary oestrone and gonadotropin secretion in pubertal females. Seven females were observed when they resided with family members, in isolation, and after pairing with an unfamiliar male. Initially, the females were housed either in their natal group or with a familiar male(s) only. When housed in isolation, the females were exposed daily to either male urine or water. Neither urinary hormone levels nor sociosexual behaviour differed between females housed with their natal group and those housed only with familiar males. In isolation, urinary oestrone and scent marking increased, but hormonal excretion was acyclic; daily exposure to male urine did not influence hormones or behaviour. Sexual behaviour was almost never observed when females lived with family members but increased significantly after pairing. One female began ovulatory cycling in the presence of a familiar male, no female began cycling in isolation, and five females began cycling after pairing. The results from this and previous studies indicate that the onset of sexual behaviour and ovarian cyclicity may require not only release from suppression by the mother but also release from suppression by other family members as well as direct contact or stimulation from an unfamiliar male. The combination of suppressive and stimulatory factors may serve as mechanisms for avoidance of inbreeding and to promote group dispersal.
Sweet insights into learning and memory.

Studies have linked the Fucα(1-2)Gal modification of neuronal glycoproteins to cognitive processes such as learning and memory. The identification of synapsins Ia and Ib as the main Fucα(1-2)Gal-bearing neuronal proteins not only suggests previously unknown molecular mechanisms of neuronal plasticity but also indicates the existence of previously unknown glycosylation pathways in neurons.