cssi/SciSciGPT-SciSciNet huggingface dataset:
Numerical simulation of the 3D behavior of thermal buoyant airflows in pentahedral spaces

Abstract A numerical study of three-dimensional natural convection in an attic space with heated horizontal base and cooled upper walls is presented. Every previous study pertinent to this subject as of today has assumed that the flow in attics is two-dimensional and restricted to triangular cavities. This problem is examined for fixed aspect ratios holding width to height of 2 and depth to height of 3.33 and Rayleigh numbers ranging from 10 4 to 8 × 10 5 . The coupled system of conservation equations, subject to the proper boundary conditions, along with the equation of state assuming the air behaves as a perfect gas are solved with the finite volume method. In the conservation equations, the second-order-accurate QUICK scheme was used for the discretization of the convective terms and the SIMPLE scheme for the pressure-velocity coupling. It is categorically found that the flow in the attic is 3D. From the physics of the problem, two steady-state solutions are possible. The symmetrical solution prevails for relatively low Rayleigh numbers. However, as the Ra is gradually increased, a transition occurs at a critical value Ra C . Above this value of Ra C , an asymmetrical solution exhibiting a pitchfork bifurcation arises and eventually becomes steady. Results are presented detailing the occurrence of the pitchfork bifurcation and the resulting flow patterns are described.
Man and Superman: The Fleischer Studio Negotiates the Real

It is inescapable that every culture must negotiate with technology, whether it does so intelligently or not. A bargain is struck in which technology giveth and technology taketh away.—Neil Postman...
Cell entry of one-dimensional nanomaterials occurs by tip recognition and rotation

Materials with high aspect ratio, such as carbon nanotubes and asbestos fibres, have been shown to cause length-dependent toxicity in certain cells because these long materials prevent complete ingestion and this frustrates the cell(1-3). Biophysical models have been proposed to explain how spheres and elliptical nanostructures enter cells(4-8), but one-dimensional nanomaterials have not been examined. Here, we show experimentally and theoretically that cylindrical one-dimensional nanomaterials such as carbon nanotubes enter cells through the tip first. For nanotubes with end caps or carbon shells at their tips, uptake involves tip recognition through receptor binding, rotation that is driven by asymmetric elastic strain at the tube-bilayer interface, and near-vertical entry. The precise angle of entry is governed by the relative timescales for tube rotation and receptor diffusion. Nanotubes without caps or shells on their tips show a different mode of membrane interaction, posing an interesting question as to whether modifying the tips of tubes may help avoid frustrated uptake by cells.
Automatic linearity and frequency response tests with built-in pattern generator and analyzer

We present a built-in self-test (BIST) approach based on a direct digital synthesizer (DDS) for functionality testing of analog circuitry in mixed-signal systems. A main contribution of this paper is the BIST-based hardware implementation and measurement of amplifier linearity (IP3) and frequency response, including both phase and gain. The approach has been implemented in Verilog and synthesized into a field-programmable gate array (FPGA), where it was used for functional testing of an actual device under test (DUT) and compared to simulation results
Physician opinion about electronic publications.

Abstract PURPOSE: Many medical journals are currently offering physicians the option to subscribe electronically, allowing readers access by means of the Internet. However, physicians' opinions about this innovation are not known. This exploratory study was designed to learn more about physicians' opinions and attitudes regarding electronic publications. SUBJECTS AND METHODS: A three-page questionnaire was developed to survey all physicians (faculty and house officers) at a large university-affiliated teaching hospital in Baltimore, Maryland. The questionnaire explored many of the features that make electronic journals distinct from printed journals. RESULTS: Of the 314 physicians surveyed, 255 (81%) returned a completed questionnaire. The mean (± SD) age of the respondents was 41 ± 10 years, 164 (65%) were male, and 50 (20%) were house officers. Twenty-six percent of respondents (n = 66) thought that electronic journals would lower the quality of the medical literature, and 25% (n = 63) believed that the prestige of authorship would be lessened. Seventy to eighty percent of physicians responded that electronic journals would decrease clutter in their offices and homes, be more environmentally friendly than the current system, make it easier to locate research reports that they had read, and offer the benefit of linkage to related articles. Seventy-four percent of physicians (n = 188) were concerned about losing the convenience of being able to read a printed journal anywhere. In multivariate analyses, female sex, being a faculty member (vs house officer), fewer publications, better computer skills, and more frequent use of the Internet were independently associated with positive attitudes toward various aspects of electronic journals. CONCLUSIONS: Physicians responded favorably to the many potential values and applications of electronic publications but were most concerned with the loss of the convenience that printed journals offer.
POLTICAL EFFICACY AND POLITICAL PARTICIPATION OF FAMILY‐ORIENTED PROFESSIONALS*

Political activities of home economists were found to be markedly limited. Those who reported greater amounts of participation were characterized by strong feelings of political efficacy, backgrounds of family political involvement, greater amounts of community participation, and employment in colleges or universities. Respondents not presently employed, including students, homemakers and retired persons, appeared to be the least politically active group. Implications for the academic preparation of home economists are explored.
Shape of small silicon clusters.

We propose an explanation for the experimentally observed transition in the shape of silicon clusters of size 20\ensuremath{\le}N\ensuremath{\le}40: Elongated shapes of low energy can be obtained by stacking stable subunits, while concurrent optimization of surface-to-volume ratio and surface structure leads to compact shapes. A transition in shape from elongated to compact structures is expected as the size increases beyond a critical value at which interior atoms become stable. Our proposal is backed by extensive first-principles calculations on the energetics of two classes of Si clusters, which suggest a critical size bounded by 24\ensuremath{\le}N\ensuremath{\le}28, in good agreement with experimental observations.
High-altitude retinopathy and altitude illness☆

Abstract Objective To determine the relationship between high-altitude retinopathy (HAR) and other altitude-related illnesses and establish a classification system for HAR. Design Observational case series. Participants All 40 climbers among 3 Himalayan expeditions who ascended to altitudes between 16,000 and 29,028 feet above sea level (summit of Mt. Everest) were examined for signs of HAR and altitude illness (AI). Methods All subjects had dilated fundus examinations before the ascent, intermittent fundus, and medical examinations during the climb and a dilated fundus and medical examination within 2 days after attaining their highest altitude. Main outcome measures Careful fundus drawings or fundus photography or both were obtained for all participants. All subjects gave a subjective assessment of their symptoms of acute mountain sickness (AMS) and were assessed clinically for signs of high-altitude cerebral edema (HACE). Results Nineteen of 21 climbers who ascended above 25,000 feet developed HAR. Fourteen of 19 climbers who attained altitudes between 16,000 and 25,000 feet were found to have retinopathy. A grading system for HAR describing the severity of the retinopathy was developed. Correlation of the retinopathy with other AI showed that AMS was endemic and that a statistically significant correlation exists between HAR and HACE ( P = 0.0240). Conclusion Recognizing advancing grades of HAR may allow physicians to recommend initiating empiric treatment with oxygen, steroids, diuretics and immediate descent to prevent HAR progression, macular involvement, or potentially fatal HACE. High-altitude retinopathy is both a significant component of and a predictor of progressive AI.
Encoding and arousal factors in free recall of verbal and visual material

Forty male Ss were presented 24 items, half as words and half as simple line drawings with the instruction to try to remember them. Free recall was tested immediately after presentation and 30 min later. Picture recall was significantly greater than word recall (p <.001). Mean GSRs based on items presented as words predicted both word and picture recall (p <.001). It was suggested that the GSR findings point to a verbal encoding both for words and pictures. Since pictures appear to be coded visually as well, their double coding might provide an explanation for superior memory of these items.
Designing Safe Systems: Using System Dynamics to Understand Complexity

All geographical regions are subject to devastation and disruption from natural disasters. Optimizing safety requires understanding the natural and social systems involved in disasters, communicating clearly with decision makers that affect those systems, and identifying potentially effective interventions for consideration. The application of system dynamics modeling, a metatheoretical and methodological approach of systems theory, helps to accomplish all three. After a brief reference to system’s current place in hazards research and practice, the usefulness and types of systems models, including causal loop diagrams and stock and flow diagrams, are discussed. The methodological specification of system dynamics modeling is explained, along with the general modeling process. Conclusions are advanced with a discussion of the application of system dynamics modeling in hazards work and its place in designing safe systems.
Physical and Functional Properties of 10% Salted Egg Yolk in Mayonnaise

Stability of mayonnaise prepared from 10% salted egg yolk was decreased by freezing, spray-drying or freeze-drying of the yolk. Storage of salted yolk for 90 days further decreased stability of mayonnaise made from freeze-dried yolk but not that made from frozen spraydried yolk. Stiffness of mayonnaise was increased by pasteurization but stability was increased only at the lesser of two heat treatments. Size of fat globules in the mayonnaise was inversely related to mayonnaise stability.
Adaptive-order statistic filters for noise characterization and suppression using noisy reference

ABSTRACT In this paper several adaptive order statistic filters (OSF) are developed and compared for channel characterization and noisesuppression in images and 3-D CT data. Emphasis has been put on the situation when a noise-free reference image is notavailable but instead we can have a sequence of two noisy versions of the same image (or 3-D data slice). One of the noisyimages is used as the reference in the OSF. It is shown theoretically that if noises are not correlated, the expected values ofthe derived filter coefficients will be equal to those coefficients derived using a noise-free reference. Experiments using thenoisy reference image yield comparable results to those methods using a noise-free reference image and also better resultsthan those of median, Gaussian, averaging and Wiener filters.Keywords: Adaptive filtering; order statistics; image processing. 1. INTRODUCTION A combination of adaptive techniques [l1[3][4][8] and order statistic filter [2] has been applied for noise suppression in
Atmospheric impact of quasiliquid layers on ice surfaces

[1] We present a fully thermodynamically constrained model to calculate the thickness of the quasiliquid layer on ice surfaces and apply this model to atmospherically relevant situations to calculate the quasiliquid thickness and volume for ice aerosols and snow pack. These volumes are comparable to the liquid volumes present in a representative liquid-droplet cloud. The pure water calculations represent conservative lower bounds to the volume possible from more complex solutions. Incorporation of solution chemistry into the model demonstrates both the effect played by impurities when studying this phenomenon and how the formation of the quasiliquid layer concentrates impurities on the ice surface.
Machine scheduling with transportation considerations

In most manufacturing and distribution systems, semi-finished jobs are transferred from one processing facility to another by transporters such as automated guided vehicles (AGVs) and conveyors, and finished jobs are delivered to customers or warehouses by vehicles such as trucks. Most machine scheduling models assume either that there are an infinite number of transporters for delivering jobs or that jobs are delivered instantaneously from one location to another without transportation time involved. In this paper, we study machine scheduling problems with explicit transportation considerations. Models are considered for two types of transportation situations. The first situation involves transporting a semi-finished job from one machine to another for further processing. The second appears in the environment of delivering a finished job to the customer or warehouse. Both transportation capacity and transportation times are explicitly taken into account in our models. We study this class of scheduling problems by analysing their complexity. We show that many problems are computationally difficult and propose polynomial or pseudo-polynomial algorithms for some problems. Copyright © 2001 John Wiley & Sons, Ltd.
Messenger Functions of the Bacterial Cell Wall-derived Muropeptides

Bacterial muropeptides are soluble peptidoglycan structures central to recycling of the bacterial cell wall and messengers in diverse cell signaling events. Bacteria sense muropeptides as signals that antibiotics targeting cell-wall biosynthesis are present, and eukaryotes detect muropeptides during the innate immune response to bacterial infection. This review summarizes the roles of bacterial muropeptides as messengers, with a special emphasis on bacterial muropeptide structures and the relationship of structure to the biochemical events that the muropeptides elicit. Muropeptide sensing and recycling in both Gram-positive and Gram-negative bacteria are discussed, followed by muropeptide sensing by eukaryotes as a crucial event in the innate immune response of insects (via peptidoglycan-recognition proteins) and mammals (through Nod-like receptors) to bacterial invasion.
Bridging the gap between specification and implementation

The claim that in knowledge compilation the gap between specifications and run-time architectures is substantial is examined. The forces that create the gap are identified and discussed. Two general approaches to closing this gap are described. One approach, which has been the focus of knowledge compilation research, converts specifications into a form that the run-time architecture can interpret directly. The other approach, which has been the focus of work on model-directed reasoning and task-specific architectures, changes the run-time architecture so that it can interpret the given specifications directly. >
The discovery of ubiquitin-dependent proteolysis

In early 1980, Irwin A. Rose, Avram Hershko, and Aaron Ciechanover published two papers in PNAS that reported the astounding observation that energy-dependent intracellular proteolysis was far more complicated than the previously accepted models of lysosomal proteolysis or the action of ATP-dependent proteases such as bacterial lon. In fact, it has turned out to be even more complicated than they could have suspected. The general model of covalently attaching a small protein as a targeting signal has proved to be every bit as important to eukaryotic cells as the better understood modifications such as phosphorylation or acetylation. The key player in this modification, a small protein called ubiquitin (APF-1 in these papers), is the founding member of a large family of proteins containing the β-grasp fold and is used as a posttranslational targeting signal to modify the structure, function, and/or localization of other proteins. The story of this discovery is a textbook example of the confluence of intellectual curiosity, unselfish collaboration, chance, luck, and preparation.
Behavioral and ERP measures of attentional bias to threat in the dot-probe task: poor reliability and lack of correlation with anxiety.

The dot-probe task is often considered a gold standard in the field for investigating attentional bias to threat. However, serious issues with the task have been raised. Specifically, a number of studies have demonstrated that the traditional reaction time measure of attentional bias to threat in the dot-probe task has poor internal reliability and poor test-retest reliability. In addition, although threatening stimuli capture attention in other paradigms, attentional bias to threat has not usually been found in typical research participants in the dot-probe task. However, when attention is measured in the dot-probe task with the N2pc component of the event-related potential (ERP) waveform, substantial attentional orienting to threat is observed, and the internal reliability is moderate. To provide a rigorous comparison of the reliability of this N2pc measure and the conventional behavioral measure, as well as to examine the relationship of these measures to anxiety, the present study examined the N2pc in conjunction with reaction time in the dot-probe task in a large sample of participants (N = 96). As in previous studies, reaction time showed no bias to threatening images across the sample and exhibited poor internal reliability. Moreover, this measure did not relate to trait anxiety. By contrast, the N2pc revealed a significant initial shift of attention to threat, and this measure was internally reliable. However, the N2pc was not correlated with trait anxiety, indicating that it does not provide a meaningful index of individual differences in anxiety in the dot-probe task. Together, these results indicate a serious need to develop new tasks and methods to more reliably investigate attentional bias to threat and its relationship to anxiety in both clinical and non-clinical populations.
Kerguelen Plateau bathymetry, sediment distribution and crustal structure

Abstract The Kerguelen Plateau is a large topographic high situated in the south-central Indian Ocean, adjacent to Antarctica. The plateau rises some 2000 fathoms (∼ 3700 m) above the adjacent deep seafloor and, along its NW-SE-trending axis, exceeds 2000 km in length. The rugged northern part of the Kerguelen Plateau is dominated by NW-SE-trending normal faults and associated sediment-filled troughs and is believed to be young relative to the rest of the plateau. The central and southern parts lie in deeper water and are topographically subdued; fault trends in the central region are N-S, in the southern they are NW-SE, identical to the northern region. Sediments of Cenomanian age were sampled by a piston core taken on the eastern flank of the central region; we judge that the core penetrated the acoustic basement. Seismic profiles and piston cores from the central and southern parts of the plateau reveal a prominent sub-bottom reflector of Eocene age. It appears that significant areas of the plateau were peneplaned during the Eocene; this event was followed by general subsidence and normal faulting. Beneath the acoustic basement in the central plateau, sonobuoy measurements reveal a layer up to 1 km thick with a refraction velocity of 3.7 km/sec, underlain by material with an average velocity of 4.9 km/sec, presumably a crystalline basement. The 4.9 km/sec material must be considerably older than Cenomanian. No significant structural connection between Antarctica and the Kerguelen Plateau was observed. A sediment isopach map of the plateau and the deep ocean area to the east has been compiled. A sediment ridge paralleling the eastern margin of the plateau in abyssal depths appears to be the result of deposition by a westward-flowing bottom current that has been deflected northward by the plateau. Gravity data indicate a crust about 20–23 km thick beneath the plateau. We interpret this intermediate crustal thickness, the short-wavelength large-amplitude magnetic anomalies observed over the plateau, and other evidence discussed in the text, as evidence that the plateau is probably oceanic in origin. Anomalous depths to the top of the oceanic crust adjacent to the northeastern edge of the plateau and the plateau elevation itself are interpreted to result from a mantle hot spot, now centered beneath the active volcanoes in the northern part of the plateau. We suggest that the composite Kerguelen Plateau is an uplifted remnant of the Cretaceous ocean basin that existed to the west of Australia following the separation of India from Western Australia-Antarctica. Furthermore, it is speculated that the time transgressive eastern margin of the plateau has been created by a modest northerly drift of the locus of volcanic activity relative to the Antarctic plate.
Representation of an extended seismic source in a propagator-based formalism

Abstract A method is presented for the computation of synthetic seismograms for an arbitrary seismic source embedded in a stratified medium. The technique is applied to a source extending in three space dimensions for which the radiation has been decoupled into P , SV , and SH motions. A matrix formulation is given in which the displacements and stresses due to individual plane wave components of the P-SV and SH radiations from the source are separated into contributions at the upper and lower interfaces of the source layer where they are subtracted from the displacement-stress vector due to the total wave field. With this method, the propagator in the source layer connects only the reverberated components of the waves at the upper and lower layer interfaces, and there are no discontinuities in the displacements and stresses at the source depth. An application of Dunkin9s formulation of the Thompson-Haskell algorithm is given for the solution of the P-SV problem, along with a brief summary of the well-known propagator matrix formulation for the associated SH problem. The formulation is extended to the case of a shallow source penetrating two layers, and examples are presented for both shear and tensile sources.
C/EBPβ Regulation in Lipopolysaccharide-Stimulated Macrophages

C/EBP family members contribute to the induction of the interleukin-12 p40 gene and the genes encoding several other mediators of inflammation. Here, we show by chromatin immunoprecipitation that C/EBPβ binds the p40 promoter following lipopolysaccharide stimulation of peritoneal macrophages. However, three modes of C/EBPβ regulation reported in other cell types were not detected, including alternative translation initiation, nuclear translocation, and increased DNA binding following posttranslational modification. In contrast, C/EBPβ concentrations greatly increased following stimulation via MAP kinase-dependent induction of C/EBPβ gene transcription. Increased C/EBPβ concentrations were unimportant for p40 induction, however, as transcription of the p40 gene initiated before C/EBPβ concentrations increased. Furthermore, disruption of C/EBPβ upregulation by a MAP kinase inhibitor only slightly diminished p40 induction. Phosphopeptide mapping revealed that endogenous C/EBPβ in macrophages is phosphorylated on only a single tryptic peptide containing 14 potential phosphoacceptors. This peptide was constitutively phosphorylated in primary and transformed macrophages, in contrast to its inducible phosphorylation in other cell types in response to Ras and growth hormone signaling. Altered-specificity experiments supported the hypothesis that C/EBPβ activity in macrophages does not require an inducible posttranslational modification. These findings suggest that, although C/EBPβ contributes to the induction of numerous proinflammatory genes, it is fully active in unstimulated macrophages and poised to stimulate transcription in conjunction with other factors whose activities are induced.
Web applications and dynamic reconfiguration in UNIX servers

In recent years, several large UNIX SMP Servers have added support for dynamic resource management through partitioning and dynamic resource reconfiguration. In this paper we study the ability of Dynamic Reconfiguration (DR) to accommodate fluctuating workloads and changes in operational priorities for a commercial web application. We use a WebSphere HTTP server, a WebSphere Application Server, and a DB2 Database for the application. This combination represents a popular platform for commercial computing deployments, and supports a number of common web-based application scenarios. In our study, we treat this application as a black box to provide a realistic measurement of the efficacy of the DR technology in UNIX Servers. We also use nonparametric estimation techniques to obtain an ab initio and unbiased study of the jitters in our experimental data. Our main conclusions are: (1) Resource allocations for the application (even for a complex and function-rich middleware system such as WebSphere) can be efficiently managed by DR, without the need for explicit accommodation of the DR features by the application, and (2) To obtain efficient resource utilization, the resource management system has to empirically monitor the throughput obtained from the application, rather than rely primarily on long time-scale estimations.
Monte Carlo Simulation in Sampling Techniques of Traffic Data Collection

Traffic volume counts are used in transportation planning, design, operation, and safety analyses. A new methodology establishes a statistical basis for comparing traffic volumes generated from different samples. Monte Carlo simulation was used to generate a cumulative probability function (CPF) of traffic volumes based on the fit-of-Weibull probability distribution to a particular traffic sample. A 90% confidence interval of the traffic volumes from a given traffic sample was obtained from the CPF and was used to compare different traffic samples. A case study was performed by using this methodology to determine if shorter time-frame data may be used to represent longer-time traffic. Results from the case study show that traffic at 20-min intervals may be used to represent 1-h traffic when moderate to high traffic volumes are considered. It was observed that subsamples failed to represent the 1-h traffic data for lower traffic volumes of selected vehicle types.
Notes on the defoliation of Coconut Palm (Cocos nucifera) by the butterfly Opsiphanes quiteria quirinus in northeastern Costa Rica (Lepidoptera: Brassolidae)

The defoliation of two adjacent, mature trees of the palm Cocos nucifera by caterpillars of the butterfly Opsiphanes quiteria quirinus (Lepidoptera: Brassolidae) was studied in northeastern Costa Rica. During the early dry season (February, 1976), these trees were heavily striped of leaves by the caterpillars, producing a large number of healthy pupae that survived to produce adults. The population is characterized by non-overlapping generations on both trees. A single, non-overlapping generation produces a large number of adults that subsequently place many eggs on trees used by the previous generation. Oviposition occurs at dusk; eggs are placed singly or clustered on leaves, trunks, and the loose sheaths of fronds. Pupation occurs primarily on fronds sheaths and leaves. The infestation of caterpillars and pupae are greatest on lower fronds, presumably the result of a strong preference for oviposition on these leaves. Survivorship of at least fifth instar caterpillars in addition to pupae is high. Although Cocos palms are scarce at this locality, most of those present did not have an infestation, suggesting that either the observed heavy outbreak was unusual or that colonizing episodes are just beginning to occur here. While such outbreaks of Opsiphanes and other brassolids on banana have been documented many times in Central America, the outbreak of O. quiteria on Cocos palm in northeastern Costa Rica is a recent event, perhaps related to the increased removal of the original forest cover in recent years. On wild palms O. quiteria and other brassolids are far less abundant.
Phase equilibria in partial melting of pelitic rocks

Melting of rocks is a logical extension of normal high-grade metamorphism and there is no question that it occurs: magma exists. Many petrologists ascribe the origins of many migmatites to partial melting with segregation of solids from liquid. However, it is by no means axiomatic that all migmatites are formed essentially by this process. As we have been recently reminded by Olsen (1983), partial melting, metamorphic differentiation, injection or metasomatism are all still processes possible in the formation of migmatites, and more than one of these may be involved in the formation of a given migmatite (e.g. Johannes, 1983).
Improving the bandwidth of SBS-based slow-light delay

Frequency modulating the pump laser in SBS slow-light delay systems increases the effective Brillouin bandwidth by nearly two orders of magnitude, making the fiber Brillouin amplifier technique applicable to all-optical controllable delay of Gb/s data.
Malignant bowel obstruction: Individualized treatment near the end of life

Malignant bowel obstruction requires a highly individualized approach, tailored to the patient's medical condition, prognosis, and goals of care. Surgery should not be routinely done. Less-invasive approaches such as gastric and colonic stenting are useful.
Evaluating Algorithms for Shared File Pointer Operations in MPI I/O

MPI-I/O is a part of the MPI-2 specification defining file I/O operations for parallel MPI applications. Compared to regular POSIX style I/O functions, MPI I/O offers features like the distinction between individual file pointers on a per-process basis and a shared file pointer across a group of processes. The objective of this study is the evaluation of various algorithms of shared file pointer operations for MPI-I/O. We present three algorithms to provide shared file pointer operations on file systems that do not support file locking. The evaluation of the algorithms is carried out utilizing a parallel PVFS2 file system on an InfiniBand cluster and a local ext3 file system using a 8-core SMP.
Genetics and environmental factors play important roles in the risk for periodontal disease and edentulism

Article Title and Bibliographic Information Environmental and heritable factors in the etiology of oral diseases—a population-based study of Swedish twins. Mucci LA, Bjorkman L, et al. J Dent Res 2005;84(9):800-5. Level of Evidence 2b Purpose/Question To determine the contributions of genetics, shared environmental factors, and nonshared environmental factors within twin pairs for the risk of periodontal disease, gingivitis, and edentulism. Source of Funding Government – NIH/NIDCR Type of Study/Design Cohort study
The polarization of fluorescence and energy transfer in grana.

Abstract 1. 1. The large ratio between chlorophyll and the amount of photosynthesis produced by a short flash of light, together with the high efficiency of photosynthesis at lower light intensities, suggests that the living plant must have some mechanisms for transferring energy through the grana. 2. 2. The low polarization of the fluorescent light from living plants must be due to much of the fluorescent light being emitted by chlorophyll molecules that did not themselves absorb the exciting light. Thus the low polarization demonstrates an energy transfer between chlorophyll molecules in the living plant.
Flash Precision at the Start of Synchrony in Photuris frontalis

Synchronous flashing occurs in certain species of Southeast Asian and North American fireflies. Most Southeast Asian synchrony involves stationary congregating fireflies, but North American synchrony occurs in flying fireflies that do not congregate. Southeast Asian synchrony is usually continuous, but North American synchrony is interrupted. Photuris frontalis, the only member of the North American genus Photuris to synchronize, shows an intermittent synchrony. This involves synchronization and repeated re-synchronizations while in flight. The precision that occurs at the start of synchrony was studied in Ph. frontalis using caged fireflies and photometry. Barrier experiments (using two fireflies) or flash entrainment experiments (using one LED and one firefly) were performed to measure the temporal precision of the first entrained flash. In both cases, the first entrained flash was close to unison synchrony (phase = 1.0) and showed little variability. The behavioral implications of the ability to synchronize with the first entrained flash are not known, but it might facilitate male-male interactions during brief, transient encounters such as maintaining distance between closely flying males in search of females.
Commentary on an article by M.D. Daubs, MD, et al.: “Clinical Impression Versus Standardized Questionnaire: The Spinal Surgeon’s Ability to Assess Psychological Distress”

The authors of this interesting study should be congratulated on a well-designed and executed clinical study that raises questions regarding the assessment of emotional well-being in patients with spinal disorders. This study attempted to determine whether spinal surgeons and other nonoperative spine specialists were able to accurately assess psychological distress in patients with spinal problems. The authors asked 400 new patients who presented with spinal disorders to complete the Distress and Risk Assessment Method (DRAM) psychological distress questionnaire and then determined in a blinded fashion how accurate eight physicians were in assessing the patients’ level of distress. In general, the physicians were better able to identify patients who had a relatively normal level of stress, but their ability to identify patients who were classified as having a high level of psychological distress was poor. Spinal surgeons seemingly were worse than the nonoperative physicians in their ability to identify patients in distress. The authors advocate that all spinal surgeons and specialists should utilize the DRAM to better identify patients in psychological distress in order to improve the clinical outcomes of those patients. On …
CP**(N-1) Models at a Lifshitz Point

We consider $C{P}^{N\ensuremath{-}1}$ models in $d+1$ dimensions around Lifshitz fixed points with dynamical critical exponent $z$, in the large-$N$ expansion. It is shown that these models are asymptotically free and dynamically generate a mass for the $C{P}^{N\ensuremath{-}1}$ fields for all $d=z$. We demonstrate that, for $z=d=2$, the initially nondynamical gauge field acquires kinetic terms in a way similar to usual $C{P}^{N\ensuremath{-}1}$ models in $1+1$ dimensions. Lorentz invariance emerges generically in the low-energy electrodynamics, with a nontrivial dielectric constant given by the inverse mass gap and a magnetic permeability which has a logarithmic dependence on scale. At a special multicritical point, the low-energy electrodynamics also has $z=2$, and an essentially singular dependence of the effective action on $B={ϵ}_{ij}{\ensuremath{\partial}}_{i}{A}_{j}$.
Motion control with induction motors

Induction motors (IM) provide a very wide speed range, mechanically robust and relatively low cost motion control option. An up-to-date summary of the status of induction motor motion control technology is the subject of this paper. The topics which this paper includes are as follows: basic motion control system requirements; field orientation instantaneous torque control principles for induction motors (FO-IM); current regulators for induction motor motion control; flux and torque regulators for induction motor motion control; self commissioning and continuous self-tuning for field orientation. Technology advances based on modern control and estimation theory have the potential to further enhance the capability of this important class of servo drive systems. >
Outage probability of amplify-and-forward cooperation with full duplex relay

We study the outage performance of an amplify-and-forward (AF) cooperation with full duplex relaying (FDR). When there exists a non-negligible direct link or residual self interference (RSI), full duplex relaying turns the effective channel into a frequency selective channel. Assuming minimum mean squared error decision feedback equalization (MMSE-DFE) at the destination, we derive tight closed-form bounds on the outage probability expression for AF-FDR, and study the effect of the direct link and the RSI in the optimal duplex mode selection. It is shown that under a strong direct link, FDR becomes less beneficial due to the persistent noise amplification. Furthermore, equalizing the RSI at the destination is shown to provide more graceful performance degradation compared to a simple receiver considered in previous works, which treats the RSI as noise.
Factors affecting hospital charges after total shoulder arthroplasty: an evaluation of the National Inpatient Sample database

Background The number of total shoulder arthroplasties (TSA) performed in the United States increases yearly. At the same time, cost containment in health care continues to be a major concern. Therefore, it is imperative to identify specific variables that affect the cost of shoulder arthroplasty. Methods The U.S. National Inpatient Sample database was queried (1993-2010) to evaluate total hospital charges for shoulder arthroplasty. Etiology of arthritis, multiple medical comorbidities, and patient and hospital demographics were evaluated for their effect on total inpatient hospital charges by a multivariate analysis. Results Hospital charges for TSA increased from 1993 to 2010. Gender, race, and obesity were not associated with these differences in hospital charges. Post-traumatic and rheumatoid arthritis resulted in increased hospital charges; however, osteoarthritis resulted in decreased charges from the baseline. Multiple comorbidities (diabetes, lung disease, heart disease, and kidney disease) resulted in increased hospital charges after TSA. Regionally, the western and southern United States had the highest total charges above baseline. Larger hospitals and private urban hospitals also showed charges above baseline. Conclusions The factors related to increased hospital charges after TSA are multifactorial and include medical comorbidities, patient demographics, and regionalization. As the future of health care continues to evolve, it is important for practitioners, legislators, insurance administrators, and hospitals to recognize factors that increase costs.
Murine B-1 B Cell Progenitors Initiate B-Acute Lymphoblastic Leukemia with Features of High-Risk Disease

B-1 and B-2 B cells derive from distinct progenitors that emerge in overlapping waves of development. The number of murine B-1 progenitors peaks during fetal development whereas B-2 B cell production predominates in adult bone marrow. Many genetic mutations that underlie B-acute lymphoblastic leukemia (B-ALL) occur in the fetus, at which time B-1 progenitor numbers are high. However, whether B-ALL can initiate in B-1 progenitors is unknown. In the present study, we report that BCR-ABL-transformed murine B-1 progenitors can be B-ALL cells of origin and demonstrate that they initiate disease more rapidly than do oncogene-expressing B-2 progenitors. We further demonstrate that B-1 progenitors exhibit relative resistance to apoptosis and undergo significant growth following oncogene expression, and we propose that these properties underlie the accelerated kinetics with which they initiate leukemia. These results provide a developmental perspective on the origin of B-ALL and indicate B cell lineage as a factor influencing disease progression.
Characteristics of a collegiate recovery community: Maintaining recovery in an abstinence-hostile environment.

As adolescents have entered substance abuse treatment programs in greater numbers than ever before [Substance Abuse Mental Health Services Administration, 2004. Substance abuse treatment by primary substance of abuse. (http://www.oas.samhsa.gov/dasis.htm#teds2). Retrieved September 2004], increasing numbers of young adults are beginning college in 12-step recovery. Unfortunately, with social contexts organized around excessive alcohol consumption, colleges may be the most difficult place through which to control drinking behaviors, let alone remain abstinent. This study used data collected during 2004 and 2005 to describe members of the largest collegiate recovery community in the United States. Included in this study are the following: a description of the program that supports the community, the methods and measurements used to collect data, and results describing the substance use history and characteristics of the community members (N = 82). Collected at a large southwestern university, the data provide drug and alcohol counselors, treatment providers, school administrators, and researchers with the first description of a large collegiate recovery community.
Phosphorus uptake kinetics of a dominant tropical seagrass Thalassia testudinum

Although nitrogen is primarily the dominant nutrient limiting seagrass production in temperate estuaries, phosphorus (P) limitation can be important in tropical carbonate-dominated seagrass systems. While nitrogen uptake kinetics of seagrasses are moderately well established, very limited data exist on the dynamics of P-uptake. In this study, we determined the kinetics of dissolved inorganic phosphorus (Pi) uptake for a dominant tropical seagrass Thalassia testudinumacross a range of Pi levels (0.5–25M). Under this broad range, leaf Pi-uptake (mol g −1 dw h −1 ) rates were similar under light (Vmax = 1.90) and dark (Vmax = 2.10) conditions, while root Pi-uptake rates declined 30% in the dark, and were significantly lower than leaves under both light ( Vmax = 0.57) and dark (Vmax = 0.38) conditions. At lower Pi concentrations (0.5–5.0M), leaf Vmax was 2–3-fold lower (0.50–0.77), while root Vmax was the same at high and low Pi ranges. Based on linear and non-linear models of Pi-uptake kinetics for T. testudinum, leaves can contribute a majority of the P sequestered by the plant when surface and porewater Pi levels are equally low (0.05–0.5M). Based on the calculated P-demand of T. testudinum in South Florida, solely root or leaf uptake can account for the P requirements of T. testudinum when porewater or surface water Pi levels are 0.5M. However, when surface and porewater Pi levels are extremely low (<0.10M), such as in Florida Bay and other carbonate seagrass systems where Pi sequestration by the sediment is highly efficient, even root + leaf Pi-uptake rates do not meet the P requirements for growth and P-limitation may occur. © 2003 Elsevier Science B.V. All rights reserved.
Diabetic Neuropathy and Microcirculation

The microcirculation in diabetic and neuropathic feet is subject to the same changes found in other end organs of diabetic patients, such as the retina or the kidney. Complications such as foot ulceration lead to further morbidity and hospitalizations. Research into the causes of microcirculatory dysfunction has revealed an interplay of numerous factors. The most prominent findings are impaired endothelium-dependent and -independent vasodilation and reduced or absent nerve-axon reflex-related vasodilation. This renders the diabetic foot unable to mount a vasodilatory response under conditions of stress, such as injury, and makes it functionally ischemic even in the presence of satisfactory blood flow under normal conditions.
Gender differences in vascular smooth muscle reactivity to increases in extracellular sodium salt.

Hypertension is more common in men and postmenopausal women than in premenopausal women, and gender differences in sensitivity to high dietary Na + salt have been suggested; however, the vascular mechanisms involved are unclear. We investigated whether increases in the extracellular concentration of Na + ([Na + ] e ) enhance the mechanisms of vascular smooth muscle contraction and whether the vascular effects of [Na + ] e exhibit gender differences. Isometric contraction and 45 Ca 2+ influx were measured in endothelium-denuded aortic strips that were isolated from intact male, intact female, castrated male, and ovariectomized (OVX) female Sprague-Dawley rats and incubated in Krebs’ solution (2.5 mmol/L Ca 2+ ) containing increasing [Na + ] e by the addition of 1, 3, 6, 10, 20, and 30 mmol/L NaCl. Increasing [Na + ] e for 30 minutes did not increase the resting tone or 45 Ca 2+ influx in any group of rats. Phenylephrine (Phe) caused concentration-dependent increases in contraction and 45 Ca 2+ influx. In vascular strips from intact males, increasing [Na + ] e by the addition of 1 to 6 mmol/L NaCl significantly increased the magnitude of Phe contraction and 45 Ca 2+ influx. Further increases in [Na + ] e by the addition of 10, 20, and 30 mmol/L NaCl increased Phe-induced 45 Ca 2+ influx but inhibited Phe contraction, possibly because of excessive increases in ionic strength. Preincubation with 2,4-dichlorobenzamil (10 −5 mol/L), inhibitor of the Na + -Ca 2+ exchanger, or KB-R7943 (10 −5 mol/L), selective inhibitor of the reverse mode of the Na + -Ca 2+ exchanger, abolished the increases in Phe contraction and 45 Ca 2+ influx at increasing [Na + ] e obtained by the addition of 1 to 6 mmol/L NaCl. Preincubation in Krebs’ solution containing control [Na + ] e plus 1 to 6 mmol/L LiCl or N -methyl-d-glucamine did not increase Phe contraction. In intact females, the Phe contraction and Ca 2+ influx were less than those in intact males and were not enhanced with increases in [Na + ] e . The enhancement of Phe contraction and Ca 2+ influx with increases in [Na + ] e were not significantly different between castrated male rats and intact male rats but were greater in OVX female rats than intact female rats. In OVX female rats or castrated male rats treated with 17β-estradiol (but not 17α-estradiol) subcutaneous implants, no significant changes in Phe contraction or Ca 2+ influx with increases in [Na + ] e were observed. In OVX female or castrated male rats simultaneously treated with 17β-estradiol plus the estrogen receptor antagonist ICI 182,780, the Phe contraction and Ca 2+ influx were enhanced with increases in [Na + ] e . Thus, in intact male rats, small physiological increases in [Na + ] e enhance smooth muscle contraction to Phe by a mechanism involving Ca 2+ entry, possibly via the reverse mode of the Na + -Ca 2+ exchanger. This mechanism appears to be reduced in the presence of endogenous or exogenous estrogen and thereby protects female rats against excessive increases in vascular reactivity during high dietary Na + intake.
Neuronal NOS gene expression in gastrointestinal myenteric neurons and smooth muscle cells.

Nitric oxide synthase (NOS) has been characterized in different tissues, and its localization has been suggested in different neuronal tissues, including the myenteric neurons and other nonneuronal...
INPATIENT PRACTICE: An Integrated Framework

A framework for practice that integrates nursing concepts and processes with system concepts has distinct advantages. Nursing concepts provide direction for nursing care; the nursing process provides the structure in which nursing care is delivered and evaluated. Application of system concepts enables the CNS to navigate and negotiate the larger institutional context. Inpatient practice is not just the delivery of quality patient care; it also involves managing the system so it is possible to deliver care. An integrated framework has been offered as a guide to inpatient practice. Although further use and testing are indicated, so far it has proved useful in the practice of a CNS.