cssi/SciSciGPT-SciSciNet huggingface dataset:
Bacteremia in Staphylococcus aureus pneumonia: Outcomes and epidemiology ☆ ☆☆

Abstract Purpose Staphylococcus aureus represents a major cause of pneumonia in critically ill patients. Although bacteremia may complicate S aureus pneumonia, the epidemiology of and outcomes associated with bacteremia in this syndrome are poorly described. Materials and Methods We retrospectively identified (January 2005–December 2007) all patients admitted to the hospital with S aureus pneumonia necessitating mechanical ventilation. All subjects underwent lower airway and concurrent blood cultures. The prevalence of bacteremia served as a primary end point. We assessed the impact of bacteremia on mortality and length of stay via either logistic regression or a Cox proportional hazard model, respectively. In both models, we controlled for multiple covariates (eg, demographics, severity of illness, comorbidities, and appropriateness of initial antibiotics). We subsequently developed a prediction rule to identify subjects likely to have concurrent bacteremia based on variables assessed at the time of presentation. Results The cohort included 59 patients (mean ± SD age, 58.0 ± 17.4 years; 55.9% male, 59.3% methicillin resistant, 39.0% crude mortality). Bacteremia complicated nearly 20% of cases. The mortality rate in those with bacteremia was 39.1% vs 8.3% in persons without bacteremia ( P = .007). Three variables were independently associated with mortality in S aureus pneumonia: age, need for vasopressors, and concurrent bacteremia. Bacteremia independently conferred a 6-fold increase in the risk for death (adjusted odds ratio, 5.96; 95% confidence interval [CI], 1.08-33.10). Bacteremia also correlated with a longer length of stay. The adjusted hazard ratio for remaining hospitalized if bacteremic was 2.65 (95% CI, 1.14-6.18). For the clinical prediction rule for concurrent bacteremia, we assigned points as follows: 2 points if the patient had received prior antibiotic therapy and 1 point each for acute lung injury and for the need for vasopressors. As the total score increased, the prevalence of bacteremia increased ( P S aureus pneumonia, the scoring system had good predictive value. The area under the receiver operating curve measured 0.83 (95% CI, 0.72-0.94). Conclusions Bacteremia often arises in S aureus pneumonia and is associated with both increased morbidity and mortality. Several simple clinical factors to determine clinical features identify patients with S aureus pneumonia likely to have simultaneous bacteremia.
Identification and genomic organization of human tRNALys genes.

In eucaryotes the genes for single tRNA species exist in multiple copies, but the genomic organizations of such gene families are quite varied. The members of a tRNA gene (tDNA) family can be scattered throughout the genome, as is the case in yeast 11] and silkworm 12]. A tDNA family may also have its members irregularly clustered at a number of genomic loci, where clusters may be composed exclusively of multiple copies of one species or have several different species intermingled [3-6]. Xenopus laevis has a cluster of 8 tRNA genes (2 tRNA Met genes and 1 each of 6 other types) located in a 3.18 kilobase segment of DNA that is tandemly repeated several hundred times [7,8] (S.G. Clarkson, personal communication). In humans there are 1 0 0 0 t R N A genes/ haploid genome, corresponding to 6 0 different tRNA species [9,10]. Thus, 10-20 copies of each tDNA are expected/haploid genome. In the only specific case examined, 12 tRNA Met genes were found throughout the human genome in an arrangement that is conserved between embryonic and adult tissues [11]. We report here that there are 14 tRNA3Ly s genes/haploid human genome, which are scattered at a number of loci and which are not closely-linked to tRNA Met genes. Polymorphism in this arrangement is not detected in genomic DNAs from several sources.
Effects of subject adjustment of cochlear implant comfort in adult Nucleus 24 users

Abstract Objectives Cochlear implant comfort level measurements are crucial to the hearing of the cochlear implant user. They influence speech perception and sound quality. Various techniques are currently used to arrive at comfort level. The purpose of this research is to examine the word recognition scores of Nucleus 24 cochlear implant users as a function of the procedure used to obtain maximum acceptable loudness levels. Study design Subjects: □ Adults between ages of 21–65 years, □ Postlingually deaf, □ At least 6 months experience using the Advanced Combination Encoders (ACE) processing strategy. Methods Comfort levels were measured using an Experimenter-adjusted Method and Subject-adjusted (or self-MAPping) Method. Two programs were created, with the measurements obtained using both programming techniques, and downloaded into their speech processor. Word recognition was evaluated at varied signal levels using these two programs. A sound quality questionnaire was then completed by each subject. Results Data is currently being collected to satisfy our hypothesis that subjects' self-MAPping will result in more accurate comfort level settings, and subsequently optimal cochlear implant programs. Therefore, patients will have better speech perception skills and report improved sound quality. Conclusion If this hypothesis is correct, we can continue to more confidently apply this technique to the pediatric and adolescent population. It may also give rise to more automated, audiologist-supervised cochlear implant programming.
A temporal analysis of the synthesis of the mRNA sequestered in zoospores of Blastocladiella emersonii

To determine when the dormant mRNA of Blastocladiella emersonii zoospores is synthesized, the metabolism of poly(A) RNA and rRNA was studied during growth and sporulation using pulse-chase techniques. Zoospore poly(A) RNA is synthesized at all stages of the growth cycle investigated in cultures grown either on a normal 15-hr growth cycle or in minicyclic cultures induced to sporulate after only 6.5 hr growth. For cells labeled during the growth phase the specific activity of the pulse-labeled poly(A) RNA and rRNA was identical at the beginning and end of sporulation for any of the 2-hr labeling times investigated. From this it was concluded there is neither a preferential conservation nor degradation during sporulation of the poly(A) RNA and rRNA synthesized at various times during growth. Poly(A) RNA synthesized during early sporulation is preferentially degraded; in contrast, poly(A) RNA synthesized during late sporulation is conserved in the zoospore. Approximately one-third of the total zoospore poly(A) RNA accumulates during the final 15–20 min of sporulation. The accumulation rate for both poly(A) RNA and rRNA decreases as sporulation proceeds. In addition, the rate of degradation for both types of RNA decreases at later stages of sporulation.
Severe Underrepresentation of Women in Church Leadership in the Korean Immigrant Community in the United States

Women are severely underrepresented in leadership roles and positions in Korean immigrant churches in the United States. Largely based on ethnographic research or casual observations, researchers have pointed to one or another of the following as a central factor in this underrepresentation: (1) the influence of Korean Confucian patriarchal traditions, (2) the conservative theological position of Korean churches, and (3) the practical need of Korean male immigrants to create high-status positions through ethnic churches. Although these three factors are intertwined and even reinforcing in the empirical world, this article intends to illustrate them empirically and pull them into a more analytic scheme. In particular, this article analyzes: (1) denominational affiliations of churches in South Korea and their official positions on female ordination to ministers and elders; (2) denominational affiliations of Korean immigrant churches in New York and their positions on women ordination, and (3) the proportion of women head pastors in churches in Korea and that of women head pastors in Korean immigrant churches in New York.
An experimental study of the effects of catalysts on an ammonium perchlorate based composite propellant using 5 kHz PLIF

Abstract The catalytic effect of iron (III) oxide (Fe 2 O 3 ) and copper (II) oxide (CuO) on an ammonium perchlorate (AP) and hydroxyl-terminated polybutadiene (HTPB) propellant was studied. High speed (5 kHz) planar laser induced fluorescence (PLIF) and visible microscopic imaging of the surface was carried out in an effort to determine the mechanisms that account for the effect of catalysts. Diffusion flame lengths, crystal burn times, and ignition delay times for single AP crystals were measured during deflagration of catalyzed propellants at 1 atm. A long distance microscopic lens was also used to image AP crystal behavior in the presence of the catalysts. General trends observed on the surface are discussed. The addition of a transition metal oxide (TMO) catalyst greatly reduces the ignition delay times of the AP crystals while not significantly altering the coarse AP crystal burn times. The diffusion flame length was found to increase proportionally with the propellant’s burning rate. The findings of this experimental study provide evidence that the fine AP/binder mixture is affected most by the catalyst rather than the coarse AP at 1 atm.
Adsorption/thermal desorption for the determination of volatile organic compounds in water

An adsorption/thermal desorption (ATD) method for volatile organic compounds is developed using small bed volume (0.68 cm3) cartridges of the sorbent Tenax-TA. The method allows an ATD cartridge to be desorbed and analyzed with ca. 30 μl or residual water still on the cartridge. The method employs a water trap between the ATD thermal desorber and the capillary column. Results obtained indicate that (1) column plugging by ice can be avoided completely, (2) the water trap has a high transmission efficiency, (3) excellent chromatography can be obtained and (4) good comparability of results is obtainable between purge and trap and ATD for many volatile organic compounds at concentrations ranging for fractions of μg/1 to hundreds of μg/1.
Fusion of multipath tracks for a network of over-the-horizon radars

/sup O/ver-the-horizon radar (OTHR) provides wide area surveillance coverage beyond the line-of-sight horizon by the propagation of HF signals via the ionosphere. Targets with a radial velocity relative to the radar site are detected by the Doppler component of the received radar signal. A network of OTHRs with overlapping coverage provides for the detection and tracking of targets irrespective of target velocity. When tracks are formed by each radar in the network, multi-radar track fusion is necessary to clarify the surveillance picture. In addition, multipath ionospheric propagation conditions may yield multiple tracks for each target and for each radar. In this paper, a multi-radar multipath track fusion algorithm (MRMPTF) is outlined, extending the single radar multipath track fusion (MPTF) algorithm previously developed. The impact of OTHR track registration errors is discussed, and the equivalence of alternative OTHR track fusion architectures is shown.
Architecture of fluvial-dominated valley-fill deposits in the Cretaceous Fall River Formation

The Fall River Formation is a 45 m thick layer of fluvial-dominated valley-fills and shore-zone strata deposited on the stable cratonic margin of the Cretaceous Western Interior Seaway. Fall River deposits in Red Canyon, in the south-west corner of South Dakota (USA), expose a cross-section of a 3.5 km wide valley-fill sandstone and laterally adjacent marine deposits. The marine deposits comprise three 10 m thick upward-shoaling sequences; each composed of multiple metres-thick upward-coarsening successions. The lower two of these sequences are laterally cut by the valley-fill sandstone, and are capped by metres-thick muddy palaeosols. The upper sequence spans the top of the valley-fill sandstone, and is overlain by the Skull Creek Shale. The 30 m thick valley sandstone is partitioned into four distinct fills by major erosion surfaces, and each of these fills contain many metres-thick channel-form bodies. Deposits in the lower parts of these fills are sheet-like, top-truncated channel bodies, whereas deposits in the upper parts of fills are upward-concave, laterally amalgamated channel bodies, more completely preserved heterolithic channel bodies, or wave-deposited sheets. Each valley-fill basal erosion surface records an episode of valley incision and relative sea-level fall, and the gradual progression from fluvial to more estuarine deposits upwards within each fill records relative sea-level rise. All fills are dominantly channel deposits and are capped by marine flooding surfaces. The dominance of channel deposits, the gradual change to more estuarine facies in the upper parts of fills, and the location of flooding surfaces at valley-fill tops all suggest that sediment supply initially kept pace with relative sea-level rise and valleys filled during late marine lowstand and transgression, not during subsequent highstands. Recently proposed facies models have focused on variations in the relative strength of tide, wave and river currents as controls on valley-fill deposits. However, relative rates of sediment supply and basin accommodation change, and the shift in this ratio along the depositional profile during multiple-scale cycles in relative sea-level, are equally important controls on the style of valley-fill deposits.
A generalized conjugate gradient, least square method

A generalizeds-term truncated conjugate gradient method of least square type, proposed in [1a, b], is extended to a form more suitable for proving when the truncated version is identical to the full-term version. Advantages with keeping a control term in the truncated version is pointed out. A computationally efficient new algorithm, based on a special inner product with a small demand of storage is also presented. We also give simplified and slightly extended proofs of termination of the iterative sequence and of existence of ans-term recursion, identical to the full-term version. Important earlier results on this latter topic are found in [15, 16, 8 and 11].
Reactive nitrogen distribution and partitioning in the North American troposphere and lowermost stratosphere

A comprehensive group of reactive nitrogen species (NO, NO2, HNO3, HO2NO2, PANs, alkyl nitrates, and aerosol-NO3) were measured in the troposphere and lowermost stratosphere over North America and the Atlantic during July/August 2004 (INTEX-A) from the NASA DC-8 platform (0.1-12 km). Less reactive nitrogen species (HCN and CH3CN), that are also unique tracers of biomass combustion, were also measured along with a host of other gaseous (CO, VOC, OVOC, halocarbon) and aerosol tracers. Clean background air as well as air with influences from biogenic emissions, anthropogenic pollution, biomass combustion, and stratosphere was sampled both over continental U. S., Atlantic and Pacific. The North American upper troposphere was found to be greatly influenced by both lightning NO(x) and surface pollution lofted via convection and contained elevated concentrations of PAN, ozone, hydrocarbons, and NO(x). Under polluted conditions PAN was a dominant carrier of reactive nitrogen in the upper troposphere while nitric acid dominated in the lower troposphere. Peroxynitric acid (HO2NO2) was present in sizable concentrations always peaking at around 8 km. Aerosol nitrate appeared to be mostly contained in large soil based particles in the lower troposphere. Plumes from Alaskan fires contained large amounts of PAN and very little enhancement in ozone. Observational data suggest that lightning was a far greater contributor to NO(x) in the upper troposphere than previously believed. NO(x) and NO(y) reservoir appeared to be in steady state only in the middle troposphere where NO(x)/NO(y) was independent of air mass age. A first comparison of observed data with simulations from four 3-D models shows significant differences between observations and models as well as among models. These uncertainties likely propagate themselves in satellites derived NOx data. Observed data are interpreted to suggest that soil sinks of HCN/CH3CN are at best very small. We investigate the partitioning and interplay of the reactive nitrogen species within characteristic air masses and further examine their role in ozone formation.
The muscle spindle in cortisone-induced muscular atrophy

Abstract The muscle spindles in serially sectioned rat extensor digitorum longus (EDL) and soleus (SOL) muscles were studied histologically and histochemically after chronic cortisone administration. Nuclear chain fibers were found to be significantly atrophied in the EDL but not in the SOL. Nuclear bag fibers were not significantly affected in either muscle. Nuclear chain fibers all stained darkly with the pH 9.4 myofibrillar adenosine triphosphatase (ATPase) reaction (type II) and also stained darkly with the succine dehydrogenase (SDH) reaction. Nuclear bag fibers showed mostly light ATPase staining (type I) and dark, light, or intermediate SDH staining. Extrafusal fibers showed preferential type II fiber atrophy in EDL with relative sparing of type II fibers in SOL. The results suggest that histochemical characteristics that we have evaluated are alone insufficient to explain the differential susceptibility of skeletal muscle fibers to corticosteroids and, therefore, do not in themselves define either a myopathic or neurogenic etiology for the observed muscle wasting.
Chromatography theory: Application to supercritical fluid extraction

The adsorption equilibrium constants for naphthalene on alumina have been measured in the presence of subscritical and supercritical carbon dioxide by the dynamic tracer response technique. The equilibrium constants decrease with increases in density, and the isochroic temperature dependency is very small at supercritical conditions. Through chromatography theory, an expression has been developed for the density dependency of the capacity factor, a quantity related to the adsorption equilibrium constant by the porosity and density of the particle and the porosity of the bed, in terms of the partial molar volume of the solute at infinite dilution in the fluid phase. The partial molar volumes extracted from the data agree well with the published data. Investigation of the dynamics of the bed shows that a model, including axial dispersion and effective diffusion into the pores, successfully represents the data. The effective diffusivities and the axial dispersion coefficients were also extracted from the second central moments of the response curves at each condition.
On the bias of Huffcutt and Arthur's (1995) procedure for identifying outliers in the meta-analysis of correlations.

This study documents how the use of A. I. Huffcutt & W. A. Arthur's (1995) sample adjusted meta-analytic deviancy (SAMD) statistic for identifying outliers in correlational meta-analyses results in inaccuracies in mean r. Monte Carlo simulations found that use of the SAMD resulted in the overiden-tification of small relative to large correlations as outliers. Furthermore, this tendency to overidentify small correlations was found to increase as the magnitude of the population correlation increased and resulted in mean rs that overestimated the population correlation. The implications for meta-analysts are discussed, and 2 possible solutions are offered.
Ligands for the peroxisome proliferator-activated receptor-γ and the retinoid X receptor exert additive anti-inflammatory effects on experimental autoimmune encephalomyelitis

Abstract Peroxisome proliferator-activated receptor-gamma (PPAR-γ) is a member of the nuclear-receptor superfamily that binds to DNA with retinoid X receptors (RXRs) as PPAR–RXR heterodimers. In experimental autoimmune encephalomyelitis (EAE), the gene expression of PPAR-γ was demonstrated in spinal cord during the course of EAE. Administration of 15-deoxy- 12,14 -prostaglandin J2 (15d-PGJ2) or 9- cis -retinoic acid (RA) alone at the onset of clinical signs of EAE reduced the severity of disease, however, their combination resulted in enhanced amelioration of disease. These results suggest that use of RXR specific ligands may be highly effective when combined with PPAR-γ agonists in the treatment of autoimmune demyelinating diseases such as multiple sclerosis (MS).
Extrapolating (e,e'p) to (e,e')

Unexplained anomalies in quasielastic (e,e') measurements motivated (e,e'p) experiments to determine the reaction mechanisms (single-nucleon knockout, multinucleon knockout, delta production, etc.) involved in quasielastic electron scattering. In this paper we use various models to extrapolate from C(e,e'p) measurements, where an outgoing proton is detected in a small solid angle centered around the virtual photon angle, to C(e,e') measurements, which integrate over all knockedout particles at all angles. Extrapolated single nucleon knockout (p and s shell) only accounts for 25% of the (e,e') cross section in the dip region and only 40--60 % in the quasielastic region. This indicates that the ``quasielastic'' region has a large nonquasielastic component. Various multinucleon knockout models (two-nucleon correlations, six-quark bags, and qualitative final state rescattering) are compared to C(e,e'p) missing energy spectra and to the difference between the (e,e') cross section and the extrapolated single-nucleon knockout; none completely describe the data.
Reflection and transmission of pulsed electromagnetic fields through multilayered biological media

The reflection and transmission of ultrawideband electromagnetic pulses through multi-layered biological media consisting of three biological tissue layers representing skin, fat and muscle is analyzed. The frequency dependent reflection and transmission coefficients of the multilayer stack are computed using the transfer matrix method. Each of the three tissues is modeled as a homogeneous, isotropic, linear, dispersive, attenuative, dielectric with frequency dispersion described by a multiple relaxation Rocard-Powles-Debye model fit to experimental data.
System implications of memory reliability in exascale computing

Resiliency will be one of the toughest challenges in future exascale systems. Memory errors contribute more than 40% of the total hardware-related failures and are projected to increase in future exascale systems. The use of error correction codes (ECC) and checkpointing are two effective approaches to fault tolerance. While there are numerous studies on ECC or checkpointing in isolation, this is the first paper to investigate the combined effect of both on overall system performance and power. Specifically, we study the impact of various ECC schemes (SECDED, BCH, and chip-kill) in conjunction with checkpointing on future exascale systems. Our simulation results show that while chipkill is 13% better for computation-intensive applications, BCH has a 28% advantage in system energy-delay product (EDP) for memory-intensive applications. We also propose to use BCH in tagged memory systems with commodity DRAMs where chipkill is impractical. Our proposed architecture achieves 2.3× better system EDP than state-of-the-art tagged memory systems.
A Teacher’s Mediation of a Thinking-Aloud Discussion in a 6th Grade Mathematics Classroom

This article presents a Vygotsky-inspired analysis of how a teacher mediated a “thinking aloud” whole-group discussion in a 6th grade mathematics classroom. This discussion centered on finding patterns in a triangular array of consecutive numbers as a phase towards building recursive and direct algebraic formulas. By a “thinking aloud” discussion we mean a conversation wherein students exchange and further develop ideas-in-the-making with their peers under the teacher’s guidance. Drawing upon Halliday’s systemic functional linguistics (SFL), we treated the selected discussion as a text. We then analyzed how the teacher mediated the conjoined making of this text so that it served as an interpersonal gateway for students to practice searching for patterns and signifying these patterns in propositional form. This analysis was guided by the following questions: How did the discussion as a text-in-the-making mean what it did? What was the role of the teacher in the conjoined making of this text? Our study illustrates the power of SFL for capturing the inner grammar of instructional conversations thus illuminating the complexities and subtleties of the teacher’s role in mediating semiotic mediation in mathematics classrooms.
Fearless Cards: a low-tech solution to help overcome emotional barriers to ICT adoption among marginalized populations

We discuss access, skills, and emotional barriers to computer literacy among immigrant day laborers in the USA, and we prototype Fearless Cards (www.fearlesscards.org), a novel design to help these and other underserved communities overcome emotional barriers to computer and internet use. In addition to lacking technical skills, day laborers experience strong emotional barriers: fear, anxiety, lack of self-confidence, and limited English language skills. Through an iterative process of design and testing in partnership with a non-profit in Seattle, Washington, USA, we developed the Fearless Cards, a set of basic, easy-to-use instructions to help extremely underserved populations overcome their fears and lack of self-confidence to learn to use computers and the internet in ways that help them improve their lives. Fearless Cards are important because they help reach the deep pockets of exclusion and allow people who are extremely marginalized to gain self-confidence and break the emotional barriers that prevent them from starting to use computers and the internet.
Implicit state minimization of non-deterministic FSMs

This paper addresses state minimization problems of different classes of non-deterministic finite state machines (NDFSMs). We present a theoretical solution to the problem of exact state minimization of general NDFSMs, based on the proposal of generalized compatibles. This gives an algorithmic frame to explore behaviors contained in a general NDFSM. Then we describe a fully implicit algorithm for state minimization of pseudo non-deterministic FSMs (PNDFSMs). The results of our implementation are reported and shown to be superior to a previous explicit formulation. We could solve exactly all but one problem of a published benchmark, while an explicit program could complete approximately one half of the examples, and in those cases with longer run times.
Teaching Students to Use Summary Statistics and Graphics to Clean and Analyze Data

Textbooks and websites today abound with real data. One neglected issue is that statistical investigations often require a good deal of “cleaning” to ready data for analysis. The purpose of this da...
Modeling and simulation of a ground based sense and avoid architecture for Unmanned Aircraft System operations

The safe operation of Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS) requires a capability to sense and avoid other airborne targets. One solution is a Ground Based Sense and Avoid (GBSAA) concept, in which available radar surveillance information is fused in a specially tuned tracking system and provided to a ground observer and pilot through a UAS-centric display. Our current research focuses on assessing system performance for detecting pop-up, non-cooperative (non-transponding) airborne intruders. Detection and tracking of a new target depends on site-specific radar coverage performance and tracker filtering and initiation logic. Appropriate radar and tracking models enable simulation studies for assessing system performance in satisfying necessary sense and avoid functional requirements. This information will help identify needed changes in radar and tracking systems, modifications to the GBSAA concept of operation, and mission planning. Ultimately, a quantitative assessment of the GBSAA surveillance capabilities in detecting and tracking non-cooperative intruders will define where UAS can be safely operated in the NAS.
Advances in media theory

Media theory is a new branch of mathematical social and behavioral sciences with applications ranging from combinatorics to political sciences. Because of the generality of the concept of a medium and the natural character of its defining axioms, we believe the theory has a potential to become a new methodology for the management of imprecise, uncertain or incomplete information. In this paper, we review the basic concepts of media theory and present some advances in its combinatorial and stochastic parts. We prove that any medium is isomorphic to a submedium of a complete oriented medium and characterize these submedia. We also present some results concerning the stochastic evolution of a complete oriented medium and some of its submedia.
Creative Leadership for Directing Changes

With technological superiority and globalization, critical changes in the world have lead to uncertainty and ambiguity towards the future. By understanding these dynamics, creative leaders position themselves to lead organizations toward a more desirable direction. Specifically, leaders play a dual role to facilitate employees’ creativity and organizational innovation. The aim of this paper is to highlight the importance of creative leadership in organizational settings, especially for the purpose of confronting turbulence and fast-changing environments. It starts by discussing the definition of creative leadership. It then moves on to discuss three theoretical frameworks related to creativity, considering wider implication for creative leadership. The paper concludes with some barriers and useful tactics for the implementation of creative leadership for directing change.
Cdc42-interacting protein–4 functionally links actin and microtubule networks at the cytolytic NK cell immunological synapse

An essential function of the immunological synapse (IS) is directed secretion. NK cells are especially adept at this activity, as they direct lytic granules to the synapse for secretion, which enables cytotoxicity and facilitates host defense. This initially requires rearrangement of the actin cytoskeleton and, subsequently, microtubule-dependent trafficking of the lytic granules. As these two steps are sequential, specific linkages between them are likely to serve as critical regulators of cytotoxicity. We studied Cdc42-interacting protein–4 (CIP4), which constitutively interacts with tubulin and microtubules but focuses to the microtubule organizing center (MTOC) after NK cell activation, when it is able to associate with Wiskott-Aldrich syndrome protein (WASp) and the actin filament–rich IS. WASp deficiency, overexpression of CIP4, or parts of CIP4 interfere with this union and block normal CIP4 localization, MTOC polarization to the IS, and cytotoxicity. Reduction of endogenous CIP4 expression using small interfering RNA similarly inhibits MTOC polarization and cytotoxic activity but does not impair actin filament accumulation at the IS, or Cdc42 activation. Thus, CIP4 is an important cytoskeletal adaptor that functions after filamentous actin accumulation and Cdc42 activation to enable MTOC polarization and NK cell cytotoxicity.
In situ poly(urea-formaldehyde) microencapsulation of dicyclopentadiene

Microencapsulated healing agents that possess adequate strength, long shelf-life and excellent bonding to the host material are required for self-healing materials. Urea-formaldehyde microcapsules containing dicyclopentadiene were prepared by in situ polymerization in an oil-in-water emulsion that meet these requirements for self-healing epoxy. Microcapsules of 10-1000 microm in diameter were produced by appropriate selection of agitation rate in the range of 200-2000 rpm. A linear relation exists between log(mean diameter) and log(agitation rate). Surface morphology and shell wall thickness were investigated by optical and electron microscopy. Microcapsules are composed of a smooth 160-220 nm inner membrane and a rough, porous outer surface of agglomerated urea-formaldehyde nanoparticles. Surface morphology is influenced by pH of the reacting emulsion and interfacial surface area at the core-water interface. High yields (80-90%) of a free flowing powder of spherical microcapsules were produced with a fill content of 83-92 wt% as determined by CHN analysis.
Analyzing the roles of multi-functional proteins in cells: the case of arrestins and GRKs

Most proteins have multiple functions. Obviously, conventional methods of manipulating the level of the protein of interest in the cell, such as over-expression, knockout or knockdown, affect all of its functions simultaneously. The key advantage of these methods is that over-expression, knockout or knockdown does not require any knowledge of the molecular mechanisms of the function(s) of the protein of interest. The disadvantage is that these approaches are inadequate to elucidate the role of an individual function of the protein in a particular cellular process. An alternative is the use of re-engineered proteins, in which a single function is eliminated or enhanced. The use of mono-functional elements of a multi-functional protein can also yield cleaner answers. This approach requires detailed knowledge of the structural basis of each function of the protein in question. Thus, a lot of preliminary structure-function work is necessary to make it possible. However, when this information is available, replacing the protein of interest with a mutant in which individual functions are modified can shed light on the biological role of those particular functions. Here, we illustrate this point using the example of protein kinases, most of which have additional non-enzymatic functions, as well as arrestins, known multi-functional signaling regulators in the cell.
Imaging Coronary Artery Microstructure Using Second-Harmonic and Two-Photon Fluorescence Microscopy

The microstructural basis for the mechanical properties of blood vessels has not been directly determined because of the lack of a nondestructive method that yields a three-dimensional view of these vascular wall constituents. Here, we demonstrate that multiphoton microscopy can be used to visualize the microstructural basis of blood vessel mechanical properties, by combining mechanical testing (distension) of excised porcine coronary arteries with simultaneous two-photon excited fluorescence and second-harmonic generation microscopy. Our results show that second-harmonic generation signals derived from collagen can be spectrally isolated from elastin and smooth muscle cell two-photon fluorescence. Two-photon fluorescence signals can be further characterized by emission maxima at 495 nm and 520 nm, corresponding to elastin and cellular contributions, respectively. Two-dimensional reconstructions of spectrally fused images permit high-resolution visualization of collagen and elastin fibrils and smooth muscle cells from intima to adventitia. These structural features are confirmed by coregistration of multiphoton microscopy images with conventional histology. Significant changes in mean fibril thickness and overall wall dimension were observed when comparing no load (zero transmural pressure) and zero-stress conditions to 30 and 180 mmHg distension pressures. Overall, these data suggest that multiphoton microscopy is a highly sensitive and promising technique for studying the morphometric properties of the microstructure of the blood vessel wall.
New satellites: the promise of worldwide networking

This paper examines satellite services that are expected be available within five years. The role of satellite systems to provide integrated network access to the end user is explored. Another area examined is the convergence of telecommunications services to the Internet and the use of satellites for access to the Internet. New satellite services, from companies such as Teledesic, are discussed. The systems are compared and some analysis provided to determine the potential benefits they provide to military users. Potential new uses for satellites to provide broadband access to mobile subscribers are examined. The research in these areas revealed a high potential for the success of the new satellite services. The satellite industry has recognized the demand for better and cheaper services. Their satellite systems are now trying to cover the gaps left by terrestrial services and even exploit the users' desire for small easy-to-use systems. With the introduction of the new satellite systems, users are now able to travel around the globe and stay network connected.
The effect of emergency department observational experience on medical student interest in emergency medicine

Abstract Background: In many different health care educational models, shadowing, or observational experience, is accepted as integral to introducing students to the specifics of medical specialties. Study Objectives: We investigated whether emergency department (ED) observational experiences (EDOs) affect medical students' (MSs') interest in emergency medicine (EM). Additionally, we examined how the subjective quality of clinical exposures influences this interest and the decision to recommend EDOs to other students. Methods: This is a survey of MSs at a Level 1 tertiary care university hospital during a 2-year period. The study focused on assessing perception of ED exposure, post-EDO change in EM interest, and decision to recommend EDOs to others. Results: The majority of MSs had a change in EM interest post-EDO and recommended EDOs. Both variables correlated to ED exposure ratings. Conclusions: The EDO significantly influenced MS interest in EM by providing exposure to various aspects of the ED.
Leading Through Paradox

In leading across differences, leaders are also faced with cultural paradoxes, such as those identified by cross-cultural researchers (Hampden-Turner & Trompenaars, 2000; Hofstede, 2001; House Hanges, Javidan, Dorfman, & Gupta, 2004; Schwartz, 1992) between cultural forces of individualism and collectivism, achievement and ascription, long- and short-term orientation, and low- and high-power distance. Such paradoxes can be daunting for leaders who are used to unambiguous solutions and models. The aim of this chapter is to create awareness of paradoxes faced by leaders in working across differences. In particular, I discuss how paradox presents itself across cultures and how leaders might respond. Drawing on insights from social psychology, philosophy, and the creative arts, I discuss the role of a paradoxical mindset and improvisational practice as capacities that leaders could develop in leading effectively through paradox.
Annotating Named Entities in Twitter Data with Crowdsourcing

We describe our experience using both Amazon Mechanical Turk (MTurk) and Crowd-Flower to collect simple named entity annotations for Twitter status updates. Unlike most genres that have traditionally been the focus of named entity experiments, Twitter is far more informal and abbreviated. The collected annotations and annotation techniques will provide a first step towards the full study of named entity recognition in domains like Facebook and Twitter. We also briefly describe how to use MTurk to collect judgements on the quality of "word clouds."
Reactive oxygen metabolites, antioxidants and head and neck cancer.

This manuscript will review the probable role of reactive oxygen metabolites (ROM) in the etiopathogenesis of head and neck cancer (HNC). Cancer is a heterogeneous disorder with multiple etiologies including somatic and germ-line mutations, cellular homeostatic disturbances, and environmental triggers. Certain etiologies are characteristic of HNC and include infectious agents such as the Epstein-Barr virus, the use of tobacco, and consumption of alcohol. A large body of evidence implicates ROM in tumor formation and promotion. ROM species are formed in the process of cellular respiration, specifically during oxidative phosphorylation. These ubiquitous molecules are highly toxic in the cellular environment. Of the many effects of ROM, especially important are their effect on DNA. Specifically, ROM cause a variety of DNA damage, including insertions, point mutations, and deletions. Thus, it is hypothesized that ROM may be critically involved in the etiology of malignant disease through their possible impact on protooncogenes and tumor suppressor genes. Additionally, empirical evidence suggests that ROM may also affect the balance between apoptosis and cellular proliferation. If apoptotic mechanisms are overwhelmed, uncontrolled cellular proliferation may follow, potentially leading to tumor formation. Thus, this manuscript will critically review the evidence that supports the role of ROM in tumorigenesis. ROM scavengers and blockers have shown both in vivo and in vitro effects of attenuating the toxicity of ROM. Such compounds include the antioxidant vitamins (A, C, and E), nutrient trace elements (selenium), enzymes (superoxide dismutase, glutathione peroxidase, and catalase), hormones (melatonin), and a host of natural and synthetic compounds (lazaroids, allopurinol, gingko extract). Thus, this paper will also review the possible benefit derived from the use of such scavengers/blockers in the prevention of HNC.
Hierarchical reconstruction using geometry and sinogram restoration

The authors describe and demonstrate a hierarchical reconstruction algorithm for use in noisy and limited-angle or sparse-angle tomography. The algorithm estimates an object's mass, center of mass, and convex hull from the available projections, and uses this information, along with fundamental mathematical constraints, to estimate a full set of smoothed projections. The mass and center of mass estimates are made using a least squares estimator derived from the principles of consistency of the Radon transform. The convex hull estimate is produced by first estimating the positions of support lines of the object from each available projection and then estimating the overall convex hull using prior shape information. Estimating the position of two support lines from a single projection is accomplished using a generalized likelihood ratio technique for estimating jumps in linear systems. Results for simulated objects in a variety of measurement situations are shown, and several possible extensions to this work are discussed. >
Risk Factor Analysis of Permanent Pacemaker Infection

Background. Several host- and procedure-related factors have been reported to increase the risk of permanent pacemaker (PPM) infection on the basis of descriptive analyses of case series. The purpose of this study is to assess the risk factors for PPM infection using case-control study methods.Methods. All patients who had a PPM implanted at our institution from January 1991 to December 2003 were retrospectively reviewed. Each patient who experienced a PPM infection was matched with 2 control subjects by age, sex, year of implantation, and duration of follow-up. Univariate and multivariable analyses were performed to identify significant risk factors for PPM infection.Results. Twenty-nine case patients and 58 control subjects met inclusion criteria. The majority (83%) of case patients presented with a pocket infection; a minority (10%) had PPM-related endocarditis. Staphylococcus species (69%) were the most common pathogens. On univariate analysis, previous PPM infection, malignancy, long-term corticosteroid use, multiple device revisions, a permanent central venous catheter, the presence of >2 pacing leads, and a lack of antibiotic prophylaxis at the time of PPM placement were associated with an increased risk of PPM infection. A multivariable logistic regression model identified long-term corticosteroid use (odds ratio [OR], 13.90; 95% confidence interval [CI], 1.27-151.7; P=.03) and the presence of >2 pacing leads versus 2 leads (OR, 5.41; 95% CI, 1.44-20.29; P=.01) as independent risk factors for PPM infection. In contrast, use of antibiotic prophylaxis prior to PPM implantation had a protective effect (OR, 0.087; 95% CI, 0.016-0.48; P=.005).Conclusions. These findings should assist clinicians in identifying patients who are at increased risk of PPM infection, as well as in developing strategies to minimize the modifiable risks.
Friction and resistance to sliding in orthodontics: A critical review

Despite the emphasis it now receives in the marketing of self-ligating brackets, friction is not the major component of resistance to sliding in clinical treatment. Laboratory studies show that binding of the wire against the corners of the bracket, which occurs soon after tooth movement begins, is much more important than previously thought, and that notching of the archwire, which temporarily stops movement, can occur. Clinical studies support the view that resistance to bodily tooth movement by sliding has little to do with friction and, instead, is largely a binding-and-release phenomenon that is about the same with conventional and self-ligating brackets. The limited clinical trial data available now do not support the contention that treatment time is reduced (presumably because of lower friction) with self-ligating brackets.
Oncogenic Ras Represses Transforming Growth Factor-β/Smad Signaling by Degrading Tumor Suppressor Smad4

The loss of growth-inhibitory responses to transforming growth factor-beta (TGF-beta) is a frequent consequence of malignant transformation. Smad2, Smad3, and Smad4 proteins are important mediators of the antiproliferative responses to TGF-beta and may become inactivated in some human cancers. Epithelial cells harboring oncogenic Ras mutations often exhibit a loss of TGF-beta antiproliferative responses. To further investigate the effect of oncogenic Ras in TGF-beta signaling, we used an isopropyl-1-thio-beta-d-galactopyranoside-inducible expression system to express Ha-Ras(Val-12) in intestinal epithelial cells. Induction of Ha-Ras(Val-12) caused a decrease in the level of Smad4 expression, inhibited TGF-beta-induced complex formation between Smad2/Smad3 and Smad4, blocked Smad4 nuclear translocation, inhibited the TGF-beta-mediated decrease in [(3)H]thymidine incorporation, and repressed TGF-beta-activated transcriptional responses. The withdrawal of isopropyl-1-thio-beta-d-galactopyranoside or the addition of an inhibitor of the ubiquitin-proteasome pathway restored the Smad4 level and TGF-beta-induced Smad complex formation. Forced expression of Smad4 resulted in partial recovery of the TGF-beta-mediated growth inhibition and transcriptional responses in the presence of oncogenic Ras. Further, PD98059, a specific inhibitor of the MEK/ERK/mitogen-activated protein kinase pathway prevented the Ras-induced decrease in Smad4 expression and complex formation. Our results suggest a novel mechanism by which oncogenic Ras represses TGF-beta signaling by mitogen-activated protein kinase-dependent down-regulation of Smad4, thereby subverting the tumor suppressor function of TGF-beta.
Pitfalls in Interpreting Prostate Specific Antigen Velocity

AbstractPurpose: The concept of prostate specific antigen (PSA) velocity as an improved marker for prostate cancer detection is intriguing. However, before this concept is applied to individual patients several confounding parameters must be addressed. We determined the variability of serum PSA levels in men without prostate cancer.Materials and Methods: We reviewed data from a prostate cancer screening program, and determined inter-assay and individual variability of the serum PSA values for a 2-year followup period in 265 men clinically free of prostate cancer.Results: Our average inter-assay coefficient of variation was 7.5 percent. Therefore, we considered only PSA changes exceeding plus/minus 15 percent as significant. Fluctuations in serum PSA occurred in 78 percent of the men during the observation period, and 12.5 percent had at least a single PSA increase exceeding 0.75 ng./ml. per year. Fluctuations were noted throughout the entire range of serum PSA levels but became progressively larger with a...