cssi/SciSciGPT-SciSciNet huggingface dataset:
The influence of cardiograph design and automated algorithms on the incidence and detection of electrode cable reversals in an academic electrocardiogram laboratory.

Abstract Background Medical errors have been increasingly identified as a major source of morbidity and mortality in both outpatient and acute care settings. Central to the evaluation of many medical problems, the 12-lead electrocardiogram (ECG) is susceptible to both technical and interpretative errors. Proper interpretation, however, is dependent on the quality and accuracy of the acquired ECG. Methods We evaluated the impact of both a newly designed electrocardiograph and a newly developed automated computer algorithm on the incidence and detection of electrode cable reversals (lead reversals). The study tested the association of the incidence of electrode cable reversals and the design of the connection terminal. The study was performed during a 7-month period preceding (53 875 ECGs) and after (53 344 ECGs) the implementation of the new system. Electrode cable reversals occurring in various sites of the medical center were tabulated and compared. We then sought to determine if computer detection algorithms could increase point-of-care detection of electrode cable reversals and, thereby, offset the influence of cardiograph design changes. Two commercially available automated detection algorithms were compared for their abilities to identify electrode cable reversals in our study population. Results During the 7-month postimplementation period, there was a significant increase in the incidence in electrode cable reversals (0.5% vs 0.1%, P P P ≤ .0001), using a recently released automated algorithm supplied by the manufacturer. Conclusions Electrode cable reversals are a prevalent source of medical errors that receives very little attention by the clinical community. The association of an increase in electrode cable reversals with an altered electrode cable connection terminal, coupled with an increased ability to detect electrode cable reversals using the manufacturer's recently developed algorithms, emphasizes the importance of ongoing research efforts to identify technical errors in electrocardiography.
Scaling in stochastic Hamiltonian systems: A renormalization approach.

Destabilization of the period-doubling scenario in Hamiltonian systems due to noise is studied. A renormalization picture for stochastic area-preserving maps is introduced and a new universal characteristic number ..gamma../sub H/ = 17.017. . . for the noise amplitude is found. This factor governs scaling properties of the escape time from stable regions, which is demonstrated numerically as well.
Laser and electrical current induced phase transformation of In2Se3 semiconductor thin film on Si(111)

Phase transformation of thin film (∼30 nm)In2Se3/Si(111) (amorphous→crystalline) was performed by resistive annealing and the reverse transformation (crystalline→amorphous) was performed by nanosecond laser annealing. As an intrinsic-vacancy, binary chalcogenide semiconductor, In2Se3 is of interest for non-volatile phase-change memory. Amorphous In x Se y was deposited at room temperature on Si(111) after pre-deposition of a crystalline In2Se3 buffer layer (0.64 nm). Upon resistive annealing to 380°C, the film was transformed into a γ-In2Se3 single crystal with its {0001} planes parallel to the Si(111) substrate and $(11\bar{2}0)$ parallel to Si $(1\bar{1}0)$ , as evidenced by scanning tunneling microscopy, low energy electron diffraction, and X-ray diffraction. Laser annealing with 20-ns pulses (0.1 millijoules/pulse, fluence≤50 mJ/cm2) re-amorphized the region exposed to the laser beam, as observed with photoemission electron microscopy (PEEM). The amorphous phase in PEEM appears dark, likely due to abundant defect levels inhibiting electron emission from the amorphous In x Se y film.
Brain meets pancreas: netrin, an axon guidance molecule, controls epithelial cell migration

A recent publication shows that two integrins, α6β4 and α3β1, interact with netrin-1, a protein best known for its role in axon guidance. Consistent with a role in pancreatic development in vivo, netrin is expressed together with these integrins in fetal pancreatic epithelium. The paper presents strong evidence that pancreatic epithelial cells adhere, spread and migrate on netrin-coated substrata through α6β4. Data also indicate that α3β1 mediates HGF-stimulated cell migration on netrin-coated substrata. These results indicate that netrins might have much broader functions than previously suspected.
Accountability, School Reform, and Equity: The Troubling Case of Sylvan School District.

Most educational accountability systems draw upon relatively simplified indicators of student learning. Despite sufficient criticism and evidence of their misuse, test scores continue to be emphasized—even though they have a deadening effect on the very school district these accountability systems intend to primarily influence. This paper focuses on one of these low-performing school districts. The case study of Sylvan One reveals that the influence of state policy is especially circumscribed in a district like Sylvan's that is beset by such prevailing conditions as the politics of race, the culture of poverty, vacuums in communication and leadership, and the uncritical mass of human resources. Each of these conditions limits change and reform dramatically. Account-ability and reform must focus on a rigorous curriculum and well-understood standards—but only in the context of this community, replete with its problems ofrelationships, resources, andracism. These are the “three Rs” that are tantamount to creating and sustaining reform. And this approach is more about political development than anything else. Recommendations for moving beyond the traditional policymaking tools of mandates and inducements are suggested, recognizing that policy may at best promote equality, but not necessarily excellence and equity.
Ventral pallido-striatal pathway in the rat brain: A light and electron microscopic study

Most theories of basal ganglia functions have been based on a model circuit in which the flow of information follows a one-way loop proceeding from the cerebral cortex to the striatum, the pallidum/nigra, the thalamus, and then returns to the cortex. However, this model neglects data from several studies that show a direct feedback projection from the pallidum to the striatum. In this study, we have examined this feedback connection in the ventral striopallidal system to determine the morphology and chemical properties of ventral pallido-striatal projection neurons and to determine the morphology of ventral pallidal efferents in the ventral striatum. Fluoro Gold was injected into the ventral striatum to retrogradely label ventral pallidal projection neurons. Substance P immunoreactivity was used as a pallidal marker to delineate the ventral pallidum. The results show that most neurons retrogradely labeled by Fluoro Gold lie in the ventral pallidum. Additional double-labeling experiments show that none of these Fluoro Gold-labeled cells are cholinergic neurons; however, some are immunoreactive for parvalbumin, a calcium-binding protein found in many pallidal neurons. Electron microscopy revealed that the somata and dendrites of these labeled ventral pallidal projection neurons form many synapses with unlabeled terminals. Injection of Phaseolus vulgaris-leucoagglutinin into the ventral pallidum anterogradely labeled many fibers in the ventral striatum. Electron microscopy revealed that these labeled axons form both symmetric and asymmetric synapses with ventral striatal neurons. We have thus confirmed that there is a significant direct projection from the ventral pallidum to the ventral striatum. Whether this projection forms a part of either monosynaptic or polysynaptic feedback loops remains to be clarified. Nevertheless, this pallidostriatal projection must be integrated into the theories on basal ganglia functions. © 1992 Wiley-Liss, Inc.
Extensions for finite Chevalley groups I

Let G be a connected semisimple algebraic group defined and split over the field Fp with p elements, and k be the algebraic closure of Fp. Assume further that G is almost simple and simply connected and let G(Fq) be the finite Chevalley group consisting of Fq-rational points of G where q=pr for a non-negative integer r. In this paper, formulas are found relating extensions between simple kG(Fq)-modules and extensions over G (considered as an algebraic group over k). One of these formulas, which only holds for primes p⩾3(h−1) (where h is the Coxeter number of G), is then used to show the vanishing of self-extensions between simple kG(Fq)-modules except for certain simple modules when r=1 and the underlying root system is of type A1 or Cn.
Glycogen in lens of tunicate tadpole (Chordata: Ascidiacea).

The larval eye (cerebral ocellus) of an ascidian, Ciona intestinalis, possesses a lens of three cells: in the center of each is a large granular body. Several lines of evidence indicate that the lens bodies are composed of beta particles of glycogen. The granules have diameters of 300–400 A; they stain lightly with lead citrate; they are PAS positive (periodic acid Schiff reaction); they are digestible with alpha amylase; and they respond positively to Thiery's silver proteinate stain.
Optimum tilt angles for solar collectors in clear sky conditions

Abstract Solar collectors have to be tilted properly to maximize solar energy collection. Optimum tilt angles for collectors at various latitudes are determined for all 12 months of the year. These results are also applicable to collectors with a cylindrically-curved transparent cover.
How early should obesity prevention start

Overweight or obese women are likely to gain excessive weight during pregnancy. This increases their risk of disease and potentially causes higher adiposity in their offspring, who may grow up to perpetuate the intergenerational cycle of obesity and chronic disease.
ADHERENCE WITH UNIVERSAL PRECAUTIONS AFTER IMMEDIATE, PERSONALIZED PERFORMANCE FEEDBACK

We evaluated the effects of immediate, personalized performance feedback on adherence with hand hygiene by health-care staff in the context of a multiple baseline design across participants. Target behaviors reached mastery levels and were maintained near 100% throughout 2 months of maintenance probes.
Propagation of variance uncertainty calculation for an autopsy tissue analysis

When a radiochemical analysis is reported, it is often accompanied by an uncertainty value that simply reflects the natural variation in the observed counts due to radioactive decay, the so-called counting statistics. However, when the assay procedure is complex or when the number of counts is large, there are usually other important contributors to the total measurement uncertainty that need to be considered. An assay value is almost useless unless it is accompanied by a measure of the uncertainty associated with that value. The uncertainty value should reflect all the major sources of variation and bias affecting the assay and should provide a specified level of confidence. An approach to uncertainty calculation that includes the uncertainty due to instrument calibration, values of the standards, and intermediate measurements as well as counting statistics is presented and applied to the analysis of an autopsy tissue. This approach, usually called propagation of variance, attempts to clearly distinguish between errors that have systematic (bias) effects and those that have random effects on the assays. The effects of these different types of errors are then propagated to the assay using formal statistical techniques. The result is an uncertainty on the assay that has a defensiblemore » level of confidence and which can be traced to individual major contributors. However, since only measurement steps are readly quantified and since all models are approximations, it is emphasized that without empirical verification, a propagation of uncertainty model may be just a fancy model with no connection to reality. 5 refs., 1 fig., 2 tab.« less
3.5.4 On Flexibility in System Design

This paper explores the concept of flexibility in system design. Embedding flexibility in systems has become increasingly important in recent years due to the rapidly changing markets that the systems are designed to serve, their fast-evolving technology base, and the progressively longer operational lifetimes. The concepts discussed herein are intended to persuade system designers to explicitly consider issues of flexibility early in the design process. Flexibility is discussed in the context of two products of design: physical systems (e.g., spacecraft) and information systems (e.g., cockpit decision process). Separate frameworks are used to analyze each type of system, based upon distinct research directions.
Estimation of accuracy in determining protein backbone conformations from NOE data and empirical φ, ψ probability distributions

Comprehensive computational experiments were carried out to examine systematically the potential for deriving protein backbone conformations using NOE data in conjunction with the probability distribution function of known backbone conformations of amino acid residues in proteins. It is shown that, in combination with the backbone conformational probability distribution, the measurement of NOE distances with moderate precision, consistent with the precision of modem NMR methods, is adequate to produce good local conformations of the protein backbone. The apparent need for much higher precision is not a fundamental property of the problem; it arose in previous treatments only from the mathematical statement of the problem and the approaches used. To demonstrate the improved precision resulting from combined use of NOE data and the φ, ψ probability distribution, a computer program, FISINOE, was developed, and control calculations with both simulated and experimental NOE data for bovine pancreatic trypsin inhibitor were performed. An ensemble of conformations obtained from the X-ray Protein Data Bank was used to obtain an approximate probability distribution for existing conformations of amino acid residues in proteins. A comprehensive statistical analysis of the results clearly shows that the set of sequential d connectivities (data on the presence or absence of sequential NOE cross peaks related to nearest-neighbor residues), combined with prior information about existing conformations, is sufficient to obtain a satisfactorily determined local conformation of the protein backbone in most cases; in some cases it would be helpful to use, as additional information, the cross-peak intensity between the NH and CαH intraresidual protons. Comparative studies indicate that the stability and accuracy in estimating the φ and ψ angles by the FISINOE program exceed those of other traditional approaches. The principal advantages of the FISINOE method are discussed, and the extension of this method for the determination of protein three-dimensional structures is outlined.
The fitness of categories and vice versa

Two basic propositions are developed as useful in an evolutionary analysis of the origins of complex biobehavioral categories: 1. Such categories derive from the gradual accumulation of a very large number of categoric alternatives, each of which is very small, and 2. Fitness considerations provide valuable insight into the ultimate decision process whereby these micro-categories, and thus eventually, all more complex categories, are achieved.
Scheduling workflow applications on processors with different capabilities

Efficient scheduling of workflow applications represented by weighted directed acyclic graphs (DAG) on a set of heterogeneous processors is essential for achieving high performance. The optimization problem is NP-complete in general. A few heuristics for scheduling on heterogeneous systems have been proposed recently. However, few of them consider the case where processors have different capabilities. In this paper, we present a novel list scheduling based algorithm to deal with this situation. The algorithm (SDC) has two distinctive features. First, the algorithm takes into account the effect of Percentage of Capable Processors (PCP) when assigning the task node weights. For two task nodes with same average computation cost, our weight assignment policy tends to give higher weight to the task with small PCP. Secondly, during the processor selection phase, the algorithm adjusts the effective Earliest Finish Time strategy by incorporating the average communication cost between the current scheduling node and its children. Comparison study shows that our algorithm performs better than related work overall.
Validity and reliability of a smartphone application for the assessment of penile deformity in Peyronie's disease.

Abstract Introduction Available methods to evaluate men with Peyronie's disease (PD) are limited by the inability to accurately and reproducibly measure penile deformity. Aim The study aims to evaluate the performance of a smartphone application for the measurement of penile curvature and narrowing. Methods A smartphone application, the University of Washington Peyronie's Examination Network (UWPEN), was developed for this purpose. To assess penile curvature, 15 single cylinders of malleable penile prostheses were molded to varying curvature angles. Three blinded observers nonsequentially measured the angle of curvature for each prosthetic cylinder using a protractor, goniometer, and UWPEN. To assess girth narrowing, six clay models of the penile shaft were constructed to represent conditions of normal, partial hourglass, circumferential hourglass, and pencil narrowing. Girth was measured using a ruler and UWPEN by the same blinded observers. Main Outcome Measures Statistical analyses compared intertest, interobserver, and intraobserver reliability using the interclass correlation coefficient (ICC). An ICC above 0.75 indicates excellent reproducibility among measurements. Results Intertest reliability for angle measurements yielded an ICC for the three methods of 1.000. Separately, the ICC for UWPEN vs. the goniometer and protractor was 0.999 and 0.999, respectively. The interobserver ICC for UWPEN, goniometer, and protractor was 0.998, 0.999, and 1.000, respectively. Intertest reliability for girth narrowing measurements yielded an ICC of 0.991. The interobserver ICC for girth narrowing for UWPEN and the ruler was 0.978 and 0.986, respectively. Intraobserver ICC for angle measurements and girth narrowing showed high reliability for all observers and methods. Conclusions The performance of UWPEN is comparable with and highly correlated with angle measurements obtained from the goniometer and protractor as well as with girth narrowing measurements obtained from a ruler. Measurements are reproducible among different observers. UWPEN may provide a noninvasive, accurate, reliable, and widely accessible method to characterize and track PD over time. Hsi RS, Hotaling JM, Hartzler AL, HoltSK, and Walsh TJ. Validity and reliability of a smartphone application for the assessment of penile deformity in Peyronie's disease.
Broadband wavelength conversion of incoherent light in silicon nanowaveguides

We demonstrate broadband wavelength conversion of an incoherent light source via four-wave mixing in a silicon rib nanowaveguide. We observe a conversion efficiency of −24 dB over the entire wavelength range of the incoherent source.
A second-order anti-aliasing prefilter for an SDR receiver

A new architecture is presented for a sinc2(f) filter intended to sample channels of varying bandwidth when surrounded by blockers and adjacent bands. Sample rate is programmable from 5 to 40 MHz, and aliases are suppressed by 45 dB or more. The 0.13-mum CMOS circuit consumes 6mA from 1.2V
An Apparent Cluster of Congenital Hypopituitarism in Central Massachusetts: Magnetic Resonance Imaging and Hormonal Studies

Between 1980 and 1989, five infants (four males and one female) with congenital hypopituitarism were born within a relatively sparsely populated area of central Massachusetts, an incidence 25-fold greater than expected. In all infants the pituitary stalk was undetectable on magnetic resonance imaging, and a bright spot on T-1 weighted imaging, probably representing posterior pituitary tissue, was found ectopically located inferior to the median eminence. The height of the anterior pituitary remnant on magnetic resonance imaging varied from undetectable to 4 mm, and similarly, on hormonal testing a spectrum of deficiencies of GH, TSH, ACTH, and gonadotropin was observed. The magnitude of the hypopituitarism was less in the three patients whose anterior pituitary remnant was greater than 2 mm, and in them, TRH testing resulted in exaggerated TSH and PRL responses, suggestive of hypothalamic disease. In contrast, in the other two patients in whom the anterior pituitary remnant was less than 2 mm in height, h...
Chondrocyte Viability Is Higher After Prolonged Storage at 37°C Than at 4°C for Osteochondral Grafts

Background: Osteochondral allografts are currently stored at 4°C for 2 to 6 weeks before implantation. At 4°C, chondrocyte viability, especially in the superficial zone, deteriorates starting at 2 weeks. Alternative storage conditions could maintain chondrocyte viability beyond 2 weeks, and thereby facilitate increased graft availability and enhanced graft quality.Purpose: The objective of the study was to determine the effects of prolonged 37°C storage compared with traditional 4°C storage on chondrocyte viability and cartilage matrix content.Study Design: Controlled laboratory study.Methods: Osteochondral samples from humeral heads of adult goats were analyzed (i) fresh, or after storage in medium for (ii) 14 days at 4°C including 10% fetal bovine serum, (iii) 28 days at 4°C including 10% fetal bovine serum, (iv) 28 days at 37°C without fetal bovine serum, (v) 28 days at 37°C including 2% fetal bovine serum, or (vi) 28 days at 37°C including 10% fetal bovine serum. Portions of samples were analyzed by m...
How enrichment, ecosystem size, and their effects on species richness co-determine the stability of microcosm communities

Nutrient enrichment, ecosystem size, and richness each may directly affect the stability of both populations and communities. Alternatively, nutrient enrichment and ecosystem size each may directly affect richness, which in turn may affect stability. No previous studies, however, have tested empirically how these three factors interact and co-determine stability. We manipulated nutrient input and ecosystem size in replicate microcosms containing a diverse bacterial flora, and a range of green algae and heterotrophic protozoa, and used these manipulations and the resulting variation in species richness to measure their combined effects on temporal stability of both populations and communities. Results showed that nutrient enrichment and ecosystem size controlled protist richness, and their effects on stability could be mediated by richness. In addition, both community-level and population-level stability increased with protist richness. Furthermore, mean species evenness and mean species richness was negatively related. Effects of statistical averaging, overyielding, and component population stability were identified as possible mechanisms involved explaini ng the stabilizing effects of richness on community stability. Their relative strength in influencing stability, however, is likely to change as mean evenness decreased with increasing richness. This decrease in evenness would tend to weaken the strength of the statistic averaging effect, but increase the strength of the other two mechanisms due to relatively lower population variability (component population stability) and higher mean biovolumes of dominant protists (overyielding).
The influence of system compliance and sample geometry on composite polymerization shrinkage stress.

The objective of this study was to use finite-element analysis to model tensilometer tests of polymerizing dental composites. A typical sample in polymerization shrinkage stress tests is shaped like a flat disk, that is, has a high aspect ratio (ratio of diameter to height). In the experimental literature it is implied that the induced stress state in the flat disk composite samples is uniaxial. Three published tensilometer tests of curing dental composite samples with similar high aspect ratios (varying from 3 to 5) were modeled, but with test configurations having low, intermediate and high relative compliance (a tenfold variation). With the use of linear elastic finite element analysis, an instantaneous volumetric shrinkage of 1% was applied to the composite via the thermal analogy and the following questions were addressed: 1 Does the numerically predicted state of stress in composite samples tested in this fashion differ substantially from the uniaxial stress state assumed in the experiments? 2 How do the numerically predicted stresses compare with the experimentally determined nominal stresses? 3 Does compliance of the mountings influence the numerically predicted stress state? The finite-element results predicted a complex triaxial stress state that was strongly influenced by the compliance of the mountings. For the low and intermediate system compliance the model overpredicted the polymerization contraction stress, as would be anticipated due to the inability of the model to account for viscoplastic flow. For high system compliance, the numerical and experimental stress values were in better agreement, mainly because the linear elastic mountings accounted for most of the measured system compliance. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 671–678, 2002
Nearest-neighbour distribution function for systems on interacting particles

One of the basic quantities characterising a system of interacting particles is the nearest-neighbour distribution function H(r). The authors give a general expression for H(r) for a distribution of D-dimensional spheres which interact with an arbitrary potential. Specific results for H(r) are obtained, for the first time, for D-dimensional hard spheres with D=1, 2 and 3. Their results for D=3 are shown to be in excellent agreement with Monte Carlo computer-simulation data for a wide range of densities. From H(r), one can determine other quantities of fundamental interest such as the mean nearest-neighbour distance and the random close-packing density.
A comparison of elemental analysis techniques requiring no sample preparation: scanning electron microscopy and laser induced breakdown spectroscopy

Elemental analysis on samples usually involves a preparation that dissolves the sample. Two analytical techniques which enable solid phase elemental analysis are scanning electron microscopy–energy dispersive X-ray emission (SEM-EDX or simply SEM) and laser induced breakdown spectroscopy–optical emission spectroscopy (LIBS-OES or simply LIBS). Each of these techniques is capable of determining the elemental composition of the sample by looking at electron relaxation after excitation and they are compared in this study. SEM and LIBS were used to examine two samples chosen from consumer health care products, an antacid and an acid reducer. This work showed that both techniques could successfully detect active, calcium and chlorine, and inactive ingredients. While both analytical techniques were successful in detecting the elements of interest, a direct comparison of the results is difficult due to the fundamental nature of the two measurements.
A flexible Divide-and-Conquer protocol for multi-view peer-to-peer live streaming

Multi-view peer-to-peer (P2P) live streaming systems have recently emerged, where a user can simultaneously watch multiple channels. Previous work on multi-view P2P streaming solves the fundamental inter-channel bandwidth competition problem at the individual peer level, and thus can be used with very limited types of streaming protocols. In this paper, we propose a new protocol for multi-view P2P streaming, called Divide-and-Conquer (DAC), which efficiently solves the inter-channel bandwidth competition problem using a divide-andconquer strategy at the channel level, and thus is flexible to work with various streaming protocols. This makes DAC more suitable for upgrading current single-view P2P live streaming systems to multi-view P2P live streaming systems. Our extensive packetlevel simulations show that DAC is efficient in allocating the overall system bandwidth among competing channels, is flexible in working with various streaming protocols, and is scalable in supporting a large number of users and channels.
Multi-contrast reconstruction with Bayesian compressed sensing.

Clinical imaging with structural MRI routinely relies on multiple acquisitions of the same region of interest under several different contrast preparations. This work presents a reconstruction algorithm based on Bayesian compressed sensing to jointly reconstruct a set of images from undersampled k-space data with higher fidelity than when the images are reconstructed either individually or jointly by a previously proposed algorithm, M-FOCUSS. The joint inference problem is formulated in a hierarchical Bayesian setting, wherein solving each of the inverse problems corresponds to finding the parameters (here, image gradient coefficients) associated with each of the images. The variance of image gradients across contrasts for a single volumetric spatial position is a single hyperparameter. All of the images from the same anatomical region, but with different contrast properties, contribute to the estimation of the hyperparameters, and once they are found, the k-space data belonging to each image are used independently to infer the image gradients. Thus, commonality of image spatial structure across contrasts is exploited without the problematic assumption of correlation across contrasts. Examples demonstrate improved reconstruction quality (up to a factor of 4 in root-mean-square error) compared to previous compressed sensing algorithms and show the benefit of joint inversion under a hierarchical Bayesian model.
Hunting and migratory movements of white sharks in the eastern North Pacific

The aim of these studies was to determine local movements of hunting white sharks (Carcharodon carcharias) near a seal rookery and global movements during migra- tion. Seven adults were monitored locally with attached ultrasonic tags that received and telemetered animal position and behavior via an array of three-acoustic-positioning (RAP) buoys moored off Ano Nuevo Island, California. Migratory movements of 6 adults departing this island and nearby Southeast Farallon Island were tracked for 2-6 months with attached pop-up satellite archival tags. Sharks began hunting seals at Ano Nuevo Island in October, spending 40% of the day patrolling the 1 km 2 receptive field within 400 m of the island at a depth of 30 m or less. For six weeks, they did not stray far or long from the area, were equal- ly active at night as by day, were non-territorial, and fed infrequently. This nearshore phase at both island rookeries ended abruptly in winter as the sharks moved offshore to a region of the subtropical eastern Pacific halfway to Hawaii. An adult male went further, traveling to Hawaii where it remained until migrating back to California, only to repeat the journey the following year. Electronic tagging provides vital information on the hunting and migratory behavior of this apex predator.
Effects of ltp on response selectivity of simulated cortical neurons

We report here on specific ways in which synaptic long-term potentiation (LTP) affects the response selectivity of primary sensory cortical cells. LTP increases synaptic efficacy by incremental “steps,” up to a “ceiling” at which additional bursts of afferent stimulation cause no further potentiation. Endogenous and exogenous agents have been shown to modulate these two paramenters of LTP, raising the question of the functional implications associated with the sizes of steps and ceiling. We provide an analytical treatment of the effects of these two physiological LTP parameters on the behavior of simulated olfactory (piriform) cortex target cells in response to a range of inputs. A target cell's receptive field, i.e., the set of input patterns to which the cell responds, is broadened with potentiation of the cell's synapses, and is broadened more when the LTP step size is smaller, and when the LTP ceiling is higher. Moreover, the effects of step size and ceiling interact, and their joint relationship to receptive field breadth is nonlinear. Values of step size and ceiling are identified that balance the tradeoff between learning rate and receptive field breadth for particular sensory recognition tasks, and these model values are compared to corresponding known and inferred physiological values.
A beam-profile monitor for the BNL Accelerator Test Facility (ATF)

A beam-profile monitor has been designed to diagnose the 5 MeV, high-brightness electron beam from the RF gun of the BNL (Brookhaven National Laboratory) Accelerator Test Facility (ATF). The monitor consists of a phosphor screen viewed by a CCD (charge coupled device) camera. The video images are digitized and stored by a frame grabber, and analyzed on an IBM PC-AT to extract the emittance. Details of the hardware configuration are presented, along with the spatial resolution of the system measured as a function of phosphor-screen thickness. The strategies which will be used to measure the transverse and longitudinal emittances are briefly mentioned. The system should be capable of measuring a transverse geometric emittance of around 1 mm-mrad, as will be typical of the ATF beam. >
Response of Damped Oscillators to Cycloidal Pulses

In this paper, the transient response of a damped oscillator subjected to cycloidal pulses is investigated. The response is computed analytically by considering viscous and friction damping, and response spectra for relative and absolute quantities are presented for the linear viscous and sliding oscillator. The study complements the list of numerous shock spectra mostly published for the undamped linear oscillator. Subsequently, a numerical procedure based on a state-space formulation is developed to compute the response of damped oscillators when subjected to ground motions recorded near the source of strong earthquakes. It is found that although in several occasions such motions resemble to cycloidal pulses, the response of structures with low to moderate periods is substantially affected by the high-frequency fluctuations that often override the long duration pulse.
Günther Cohn-Stock, M.S., D.D.S., father of maxillary orthognathic surgery

The life of Dr. Cohn-Stock is traced and the development of the anterior maxillary osteotomy is described.
THE INFLUENCE OF MAILLARD BROWNING AND OTHER FACTORS ON THE STABILITY OF FREE TRYPTOPHAN1

The influence of various factors on the stability of free tryptophan was evaluated in several reaction systems. After treatment, tryptophan was measured by high performance liquid chromatography. Factors such as heating, protein, and glucose were responsible for tryptophan losses in a system undergoing Maillard browning. Hydrogen peroxide caused extensive losses while pH and light had minimal effect on tryptophan stability in solution. When the stability of tryptophan was compared to lysine and threonine during browning, threonine had the highest retention. At low water activity (0.22), tryptophan had the lowest retention (42%) while at a high water activity (0.75) lysine had the lowest retention (5%). When fortified corn tortillas were made using the typical heat treatment involved in preparation, retention of added lysine and tryptophan was 85–90%.
Nonlinear acoustic complexity in a fish ‘two-voice’ system

Acoustic signals play essential roles in social communication and show a strong selection for novel morphologies leading to increased call complexity in many taxa. Among vertebrates, repeated innovations in the larynges of frogs and mammals and the syrinx of songbirds have enhanced the spectro-temporal content, and hence the diversity of vocalizations. This acoustic diversification includes nonlinear characteristics that expand frequency profiles beyond the traditional categorization of harmonic and broadband calls. Fishes have remained a notable exception to evidence for such acoustic innovations among vertebrates, despite their being the largest group of living vertebrates that also exhibit widespread evolution of sound production. Here, we combine rigorous acoustic and mathematical analyses with experimental silencing of the vocal motor system to show how a novel swim bladder mechanism in a toadfish enables it to generate calls exhibiting nonlinearities like those found among frogs, birds and mammals, including primates. By showing that fishes have evolved nonlinear acoustic signalling like all other major lineages of vocal vertebrates, these results suggest strong selection pressure favouring this mechanism to enrich the spectro-temporal content and complexity of vocal signals.
Interpersonal attraction, topic importance, and proportion of item agreements

The program of research initiated by Byrne (1961) has repeatedly demonstrated that the proportion of item agreements between an individual and a hypothetical stranger represented by a test protocol is the most critical variable determining interpersonal attraction. The importance of the topic or item has only received occasional support as a determining factor. The purpose of this investigation was to contrast the effect of topic importance with the effect of proportion of item agreements as they relate to interpersonal attraction. The results of this study indicate that the effect of topic importance may be greater than had previously been thought.
Know Thyself: NK-Cell Inhibitory Receptors Prompt Self-Tolerance, Education, and Viral Control

Natural killer cells (NK) provide essential protection against viral infections. One of the defining features of this lymphocyte population is the expression of a wide array of variable cell surface stimulatory and inhibitory NK receptors (sNKR and iNKR respectively). The iNKR are particularly important in terms of NK cell education. As receptors specific for MHC class I (MHC I) molecules, they are responsible for self-tolerance and adjusting NK cell reactivity based the expression level of self-MHC I. The end result of this education is two-fold: 1) inhibitory signaling tunes the functional capacity of the NK cell, endowing greater potency with greater education, and 2) education on self allows the NK cell to detect aberrations in MHC I expression, a common occurrence during many viral infections. Many studies have indicated an important role for iNKR and MHC I in disease, making these receptors attractive targets for manipulating NK cell reactivity in the clinic. A greater understanding of iNKR and their ability to regulate NK cells will provide a basis for future attempts at translating their potential utility into benefits for human health.
Theiler's virus infection of genetically susceptible mice induces central nervous system-infiltrating CTLs with no apparent vital or major myelin antigenic specificity

Intracranial infection of susceptible mice with Theiler's virus results in persistent infection and spinal cord demyelination similar to human multiple sclerosis. While central nervous system infiltrating lymphocytes (CNS-ILs) in these mice display no virus-specific CTL activity, the cells were found to be activated killers using a specificity-independent assay. We previously demonstrated that the depletion of T cells in persistently infected mice significantly decreases demyelinating disease. Consequently, we have investigated the killing pathways employed by CNS-ILs that are isolated from persistently infected animals, the relative contribution of CD4 and CD8 cells in the generation of these CTLs, and the reactivity of this cell population to two putative autoantigens in the CNS. In vitro or in vivo manipulation of T cell populations using Abs or genetic knockout strategies demonstrate that the cytotoxic activity is primarily mediated by CD8+ T cells, and that perforin is an important molecule in the effector pathway. Since effector functions in infected mice were not inhibited by the depletion of CD4 cells with mAb but was blocked genetically in CD4 knockout mice, CD4+ T cells appear to play a helper role in the generation of CD8+ CTLs. We found no evidence of autoimmune-mediated demyelination, as the CD8+ CTLs were not reactive to two major myelin autoantigens, myelin basic protein and proteolipid protein. Our finding that CNS-ILs that are isolated from mice susceptible to persistent virus infection are neither specific for virus or myelin autoantigens is consistent with the possibility that CD8+ CTLs mediate CNS damage as a result of nonspecific activation by virus.
Fucoidin Reduces Coronary Microvascular Leukocyte Accumulation Early in Reperfusion

Background. Leukocytes rapidly accumulate in the heart early in reperfusion after ischemia, contributing to reperfusion injury. The purpose of this study was to determine whether treatment with the selectin blocker fucoidin (FCN) would attenuate early leukocyte retention in coronary venules and capillaries during low flow reperfusion. Methods. Isolated rat hearts subjected to 30 minutes of 37°C, no-flow ischemia were initially reperfused with blood containing labeled leukocytes, followed by reperfusion with a Krebs red cell solution. The deposition of leukocytes in coronary capillaries and venules was observed using intravital microscopy. Three groups were studied: nonischemic control hearts, untreated postischemic hearts reperfused at low flow, and postischemic hearts reperfused at low flow, where both the hearts and the blood reperfusate were pretreated with FCN (0.36 mg/mL blood). Results. In the ischemia-reperfusion group, we observed a rapid and significant increase in leukocyte accumulation in both capillaries and venules. Treatment with FCN significantly reduced the leukocyte accumulation in both capillaries and venules (p < 0.05). In addition, FCN significantly reduced the persistence of leukostasis in both capillaries and venules, indicating that FCN affected a transient adhesion process. Conclusions. These results suggest that the selectin family of leukocyte‐ endothelial cell adhesion proteins mediates the initial retention of leukocytes in both coronary capillaries and venules during reperfusion. Selectin blockade may be effective in reducing the contribution of leukocytes to early reperfusion injury.
On the structure of random unlabelled acyclic graphs

One can use Poisson approximation techniques to get results about the asymptotics of graphical properties on random unlabelled acyclic graphs i.e., on random unlabelled free (rootless) trees. We will use some ''colored'' partitions to get some rough descriptions of the structure of ''most'' unlabelled acyclic graphs. In particular, we will prove that for any fixed rooted tree T, almost every sufficiently large acyclic graph has a ''subtree'' isomorphic to T. We can use this result to get a zero-one law for Monadic Second Order queries on random unlabelled acyclic graphs.
Housing Type, Stress, and Family Relations

Social and psychological pathologies have been frequently associated with features of the built environment, being most prominently linked to apartment dwellings and high-rise housing, a growing part of the urban landscape. Pathology is seen as being related to housing type by way of the constraints various buildings impose. Selective support for this hypothesis is found, based on data obtained from a sample of 560 families. The most pronounced effects of multi-family housing, we find, bear more on husbands and fathers than on other family members. It is noted, however, that adverse housing effects tend to be mild, contrary to the predictions of urban critics and the more dire consequences foreseen by some urbanologists. The potential importance of the effects housing may have is highlighted by the global dimensions of current population growth. Within only the next two decades, this growth will necessitate an increase in housing stock to accommodate an additional 1.8 billion people. In the U.S. alone, approximately 24 to 42 million additional persons will require housing. The capital outlays and amount of land use implied by such population growth suggests a future departure from the realization of a single-family home, the predominant housing preference at least in North America. Accordingly, apartments and other forms of multiple-family dwellings are likely to become a major feature of our modern urban landscape. If housing types have a differential impact on their inhabitants, this development may be a cause for general societal concern. Indeed, some studies already have indicated significant adverse
EFFECT OF ELEVATION AND HOST AVAILABILITY ON DISTRIBUTION OF STERILE AND WILD MEDITERRANEAN FRUIT FLIES (DIPTERA: TEPHRITIDAE)

Effects of elevation and host fruit availability on the distribution of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), were evaluated with cylindrical traps baited with a female-biased food-based synthetic lure. Tests were conducted in the Santa Maria valley, Guatemala during a sterile male release program. Traps were placed in or near host trees (primarily coffee and citrus) and in non-host trees when no hosts were available. Trap locations were grouped according to elevation every 170 m. Elevation group midpoints were 1103, 1273, 1443, and 1613 m above sea level. The spatial distributions of sterile males, wild males, and females were clumped throughout the 13 wk of sampling. More wild female flies were captured in coffee in the 1273 m elevation and on non-host trees in the 1103 m elevation. The number of wild males was directly related to the number of wild females captured, and the sex ratio (female: male) was highest at the 1443 and 1613 m elevation ranges. There was no relationship between the number of sterile males and number of wild females in the traps at any elevation. At all elevation ranges, an inverse relationship was observed between the numbers of wild females and males with the mean numbers of sterile males per trap. Wild C. capitata populations appeared to decrease when 40 sterile males were captured per trap with wild females per week. The results indicated that, during the sampling period evaluated, coffee appeared to be the main host plant for the wild population, C. capitata were more abundant at the 1273 m elevation range than at other elevations. Additional or alternative host species may harbor the female population at other times.
Derangements on a Ferrers board

We study the derangement number on a Ferrers board B = (n × n) - λ with respect to an initial permutation M, that is, the number of permutations on B that share no common points with M. We prove that the derangement number is independent of M if and only if λ is of rectangular shape. We characterize the initial permutations that give the minimal and maximal derangement numbers for a general Ferrers board, and present enumerative results when λ is a rectangle.