cssi/SciSciGPT-SciSciNet huggingface dataset:
Sedimentary Structures and Bedding along Ephemeral Streams: ABSTRACT

Sedimentary structures are useful for interpreting conditions of deposition of sediments. Experimental studies utilizing flumes indicate the possibility of quantitative interpretations that are based on sedimentary structures. In order to bridge the gap between experimental studies and sedimentary rocks, ephemeral streams in northeastern Utah have been observed. Ephemeral streams serve as natural experiments, exhibiting End_Page 357------------------------------ all the complexity of real processes and some of the control of the laboratory. A variety of structures was observed along stream courses. With few exceptions, all of the structures resulted from infrequent floods and were developed during waning phases. In contrast, most of the bedding was deposited during maximum flood conditions. Erosional structures observed include various types of scours, rills, tool marks, microterraces, and mud balls. Structures produced by transportation and deposition were ripple marks (10 varieties), lineations (3 varieties), and imbrication. Postdepositional structures include desiccation cracks (6 varieties), surface markings, salt-crust features, algal mats, and sand volcanoes. Bedding types observed were horizontal parallel and discontinuous, small- and medium-scale trough cross-stratification, medium- and large-scale low angle wed e cross-stratification, inclined channel fill-bar complex, ripple stratification, high angle avalanche front cross-stratification, and convolute bedding. Within the channel, inclined bedding is dominant, but on bars, low angle cross-stratification is the most abundant type of bedding. Several factors combined to control the occurrence of specific structures and bedding types. Stream velocity is the most important factor, but particle size, time, water depth, and local channel irregularities are also significant. End_of_Article - Last_Page 358------------
Stochastic chemical kinetics and the quasi-steady-state assumption: Application to the Gillespie algorithm

Biochemical dynamics are often determined by series of single molecule events such as gene expression and reactions involving protein concentrations at nanomolar concentrations. Molecular fluctuations, consequently, may be of biological significance. For example, heterogeneity in clonal populations is believed to arise from molecular fluctuations in gene expression. A realistic description, therefore, requires a probabilistic description of the biochemical dynamics as deterministic descriptions cannot capture the inherent molecular fluctuations. The Gillespie algorithm [D. T. Gillespie, J. Phys. Chem. 81, 2350 (1977)] is a stochastic procedure for simulating chemical systems at low concentrations. A limitation of stochastic kinetic models is that they require detailed information about the chemical kinetics often unavailable in biological systems. Furthermore, the Gillespie algorithm is computationally intensive when there are many molecules and reaction events. In this article, we explore one approximation technique, well known in deterministic kinetics, for simplifying the stochastic model: the quasi-steady-state assumption (QSSA). We illustrate how the QSSA can be applied to the Gillespie algorithm. Using the QSSA, we derive stochastic Michaelis–Menten rate expressions for simple enzymatic reactions and illustrate how the QSSA is applied when modeling and simulating a simple genetic circuit.
Video trainers, simulation and virtual reality: a new paradigm for surgical training.

William S. Halsted established an educational system of graded learning in which surgical postgraduate trainees would, over time, do more and more of an operation as their training progressed. The apprentice model has been in place ever since, but economic pressures and work hour limitations have competed to hurry training along. A popular surgical adage is “see one, do one, teach one”, and under this model, trainees after very limited experience would be empowered to perform procedures on patients. The apprentice model may no longer be working. The National Academy of Science in 1999 and its publication To Err is Human noted that approximately 98,000 deaths occur each year due to medical error.1 In fact, they identified error in the performance of an operation as one of the many causes of mortality. The Institution of Medicine further challenged that alternative methods of surgical training needed to be developed. The cost of training is not cheap. Bridges et al broke down the financial impact of teaching surgical residents in the operating room.2 In 9,733 cases with residents versus 4,719 cases without residents, they found that cases with residents took an additional 12 minutes per case. In their analysis, they charged US$4.29/minute and assumed 1,014 US residents. The cost to society was US$53 million per year to train surgical residents in the operating room. No wonder as we scrutinize costs in the operating room, the most expensive “instrument” seems to be operative time. Halsted’s apprentice model of graded learning seems to work with general surgery in that trainees begin by making the incision, tying a knot, tying a series of knots and then performing simple procedures and eventually complex operations. However, these “open” hand skills are not transferable to laparoscopic procedures. The master “open” general surgeon may not be able to perform the most basic of laparoscopic procedures safely. Laparoscopy uses fixed ports with elongated instruments. Laparoscopy lacks the same tactile feedback and often uses a twodimensional visual system. Tying a traditional two-handed knot does not mean that the surgeon can tie an intracorporeal laparoscopic knot. So simply waiting for a junior resident to become a senior resident does not mean that they would then have the ability to perform laparoscopic surgery. Learning these techniques in the operating room may also prove too costly to the hospital; therefore, new techniques and ideas about how to train surgeons had to evolve. The laparoscopic revolution began in 1987 with laparoscopic cholecystectomy. In the early 1990s, thousands of surgeons began to embark on this new field. Most surgeons would take a weekend course which included operating on a pig before bringing the new instruments into the operating theatre for their next case. Unfortunately, the rate of common bile duct injuries increased five-fold as surgeons not expert in these techniques took on new
Shielding and securing integrated circuits with sensors

An integrated circuit (IC) Supply Chain Hardware Integrity for Electronics Defense (SHIELD) is envisioned to enable advanced supply chain hardware authentication and tracing capabilities. The suggested SHIELD is expected to be a ultra-lower power, minuscule electronic component that is physically attached to the host IC. This paper focuses on two important adversarial acts on SHIELD: physical reverse engineering and physical side-channel analysis. These attacks can be launched through mechanical or optical means and they can reveal and/or modify the confidential on-chip data or enable reverse-engineering of the design. For detection of these attacks and subsequent erasing of the sensitive data, sensors, erasure devices, and the relevant control circuitry need to be added to the SHIELD. We describe the device-level operation of the optical (photodetectors) and mechanical (nano- or micro-electromechanical switches) sensors and how they can be integrated within an IC to detect physical attacks. The operation of these micro/nano-scale sensors is unreliable due to environmental, operational, and structural fluctuations and noise. We outline system-level approaches to design a reliable countermeasure against physical attacks using unreliable sensors.
Teacher perceptions of teacher bullying

This mixed-methods study examined elementary teachers’ perceptions of teacher–student bullying. Grounded in previous research on peer bullying, the study posed several questions: to what extent did...
An essay on inequalities and order-restricted inference

Abstract This essay was prompted by a concern on the part of many senior members of the Society for Mathematical Psychology that the training of contemporary cognitive scientists exhibits a trend away from quantitative sophistication. Such a trend, if it goes unchallenged, can only serve to further marginalize mathematical psychology. There are several ways to combat this disturbing situation. Members of the Society might involve themselves more vigorously with scientific problems that are widely viewed as substantively or methodologically important, problems that require technical skill for their resolution; one example, discussed here, concerns order-restricted inference. We can also do more to encourage graduate students to develop and explore sophisticated theoretical models by giving them the tools to do so; that last battle must take place in the classroom.
SmartLabel: an object labeling tool using iterated harmonic energy minimization

Labeling objects in images is an essential prerequisite for many visual learning and recognition applications that depend on training data, such as image retrieval, object detection and recognition. Manually creating labels in images is not only time-consuming but also subject to human labeling errors, and eventually, becomes impossible for a large scale image database. Semi-supervised learning (SSL)algorithms such as Gaussian random field (GRF)can be applied to labeling objects in images since they have the ability to include a large amount of unlabeled data while requiring only a small amount of labeled data. However, the one-shot property of GRF prevents it from achieving good labeling performance. In this paper, we presents a novel object labeling tool, SmartLabel, to semi-automatically label objects in images. The algorithm of SmartLabel has four innovations over GRF:1)soft labeling,2)graph construction with spatial constraints, 3)iterated harmonic energy minimization, and 4)using relevance feedback to incorporate human interaction in the loop. As demonstrated in datasets of six object categories, the proposed SmartLabel not only works effectively even with a very small amount of user input (e.g., 1 .5%of image size)but also achieves significant improvement over GRF.
Thermodynamics of Radiative Emission Processes

A basic assumption implicit in the application of thermodynamics to the electromagnetic field is that the laws of thermodynamics are locally valid for radiative emission and absorption processes. This means that a certain minimum amount of entropy must be created by the radiative process itself. It is shown, by considering the extreme case in which the spontaneous emission of a natural spectral line is the only process taking place, that this assumption is correct, and that its validity is essentially a consequence of the uncertainty principle as expressed by the reciprocal relationship between natural line breadth and lifetime.
Distributional assessment of emerging technologies: Summary

In the project reported here, our colleagues and we undertook a cross-national, cross-technology study of the distributional effects of emerging technologies. Our central research question was how policy interventions affect distributional outcomes for the same technology under different national conditions. Our goal was to identify options for policymakers to spread the benefits of emerging technologies broadly.
Using Cross-National Studies to Illuminate the Crime Problem: One Less Data Source Left Standing

As a result of the 2005 decision by Interpol to no longer collect and disseminate police crime data, the UN biennial crime survey is now the only source of publicly available police data for studying crime trends extending over many years and covering a wide range of crimes and countries. This article assesses the effect of this “and then there was one” phenomenon through an analysis and comparison of member nation responses to the UN and Interpol crime data surveys for the year 2002. The article takes advantage of having two data sets covering police-recorded crime to analyze the quality of the UN survey data and to suggest ways to improve it. Better UN data not only will provide the basis for more robust scholarly comparisons of crime across national borders but can also yield results to illuminate crime problems worldwide.
Demographic variables are associated with knowledge, attitudes, and preventive behaviors related to environmental tobacco smoke.

Introduction: Environmental tobacco smoke (ETS) is the third leading preventable cause of death in the United States. Few biopsychosocial studies have addressed knowledge of specific ETS health effects, attitudes toward ETS, and personal preventive efforts related to ETS. Method: We surveyed a diverse U.S. community sample of convenience (N = 328) in Flagstaff, Arizona, to examine the following: (a) Does ETS knowledge measured using two response formats, open-ended (OPEF) versus closed-ended (CLEF), result in differences in apparent knowledge? and (b) what are demographic predictors of ETS knowledge, attitudes, and preventive behaviors? Results: Participants scored significantly higher on the ETS knowledge CLEF than OPEF. In regression analyses, predictors of ETS knowledge on the OPEF scale included ethnicity, age, and smoking status; the model predicting knowledge using the CLEF scale was not significant. Knowledge and smoking status, as measured on both the CLEF and the OPEF, were significant predictors of negative attitudes. Additional predictors of attitudes included income for the model using the OPEF and gender for the model using the CLEF. Predictors of preventive behaviors included attitudes and age (OPEF and CLEF models). Discussion: Differences in apparent ETS knowledge of specific ETS health effects by varying response format suggest that open-ended surveys may be useful in identifying specific content areas to address in public health education efforts. Various demographic variables predicted ETS knowledge, attitudes, and preventive behaviors, highlighting specific populations to target in public health interventions relating to ETS, such as non-White and younger populations.
Acoustooptic spectrum analysis: a high performance hybrid technique

A hybrid technique for wide-bandwidth high-resolution acoustooptic spectrum analysis is described that combines features of 2-D space-integrating and time-integrating techniques. Performance features include extended small-signal detectability, improved optical efficiency, and insensitivity to high frequency laser noise. An optically transformed periodic chirp provides a distributed local oscillator that permits wide system bandwidth.
Lymphoblastoid interferon in controlled trials of chronic hepatitis B virus infection.

A controlled trial of lymphoblastoid interferon versus no therapy in patients positive for HBsAg, HBeAg and DNA polymerase activity with separate randomisation for sexual preference and histology is underway. Thirty-two patients have been followed for a minimum period of 6 months of whom 15 have been randomised to receive interferon thrice weekly for 6 months after a 5-day induction phase. Five treated patients developed an hepatitis-like illness during the 3rd month of therapy concurrent with an abrupt and complete loss of DNA polymerase activity from serum. In 3 this was permanent and anti-HBe subsequently developed; 2 of these have also lost HBsAg. In the other 2 patients inhibition of viral replication was transient. In 5 further treated patients DNA polymerase activity was completely inhibited throughout treatment only to return as soon as interferon was withdrawn. In this group serum aminotransferase became normal during treatment. In the remaining 5 treated patients, inhibition of DNA polymerase activity was never complete and serum amino-transferases were unaffected. All the control patients remain seropositive for HBsAg, HBeAg and DNA polymerase activity. The low seroconversion rate in treated patients and the absence of seroconversion in the control group are probably a reflection of the exclusion of patients with marked elevation of serum aminotransferases. The occurrence of an hepatitis-like illness in the 3rd month of therapy in a third of the patients and the loss of HBsAg in 2 of 3 who eventually sero-converted are likely to be a consequence of therapy rather than spontaneous events. If these data prove representative of the completed trial, the results will indicate a small but real benefit from interferon therapy in patients with stable disease. Thirty male patients (27 homosexual) with biopsy proven chronic active hepatitis B were randomised to receive lymphoblastoid interferon (Wellferon) or no treatment. All patients were HBeAg positive and had continuing viral replication. Patients receiving treatment were given a single daily intramuscular injection of interferon for 28 days at a starting dose of 2.5 MU/m2 increasing to a maximum of 7.5 MU/m2/day. Transient side effects of malaise and influenza like symptoms occurred in all patients and resolved rapidly after treatment. Hepatitis B viral replication was suppressed during interferon treatment in all patients but the effect was limited to the period of therapy. After one year there was not appreciable difference in viral markers between the two groups of patients and this treatment schedule appears less effective than the thrice weekly, three month regimes recently reported from other centres.
Lesions of the Umbilicus: What the Minimally Invasive Gynecologic Surgeon Needs to Know About the Belly Button

The umbilicus is viewed as a portal by the laparoscopic surgeon, a doorway to the real business at hand. However, the umbilicus itself may be the site of a variety of lesional conditions. Some of these may be iatrogenic, caused by prior surgical interventions, such as endometriosis or seeding of a malignant neoplasm. Some may be the initial presenting complaint. This review discusses umbilical lesions that may be encountered by the minimally invasive gynecologic surgeon.
Incorporating Stochastic Road Capacity into Day-to-Day Traffic Simulation and Traveler Learning Framework: Model Development and Case Study

A key foundation for developing strategies aimed at improving the efficiency and reliability of an urban transportation network is identifying the locations and impact of system bottlenecks. Although free-flow capacity and queue discharge rates at system bottlenecks have traditionally been modeled as fixed values, they are in fact random variables. Therefore, assessing the operational impact of network bottlenecks requires reliable and realistic tools that account for stochasticity in prebreakdown flow rates and queue discharge rates. Focusing on methodological and analytic enhancements to existing dynamic traffic assignment models, this paper presents a method to seamlessly incorporate stochastic capacity models at freeway bottlenecks and signalized intersections and develops adaptive day-to-day traveler learning and route choice behavioral models under the travel time variability introduced by random capacity variations. To account for different levels of information availability and cognitive limitatio...
Phase-imaging digital holographic movies of animal cells

Multi-wavelength phase imaging digital holography is applied in acquiring holographic movies of animal microbes. Two or three lasers of different wavelengths are used to generate movies of phase maps without 2 pi discontinuities.
EVALUATING CROSS‐NATIONAL SALES PROMOTION STRATEGY: AN AUDIT APPROACH

Sales promotion is an important element of marketing communication strategy which accounts for more promotional expenditures than advertising in some countries. However, sales promotion has been generally ignored by researchers. This article briefly reviews the criteria used in the US to evaluate sales promotions and these criteria are found inadequate to guide the formulation of sales promotion internationally. Environmental sensitivity factors are identified which are overlooked in domestic sales promotions and an audit approach to planning and evaluating cross‐national sales promotion strategy is presented.
The natural course of central retinal vein occlusion

We reviewed the records of 160 patients who had central retinal vein occlusion between 1980 and 1985. Of 168 eyes, 107 (64%) were classified as nonischemic types and 61 (36%) were classified as ischemic types. Of 107 nonischemic eyes, ten (9%) converted to the ischemic variant. Of 107 nonischemic eyes, 33 (31%) lost three or more lines of visual acuity irrespective of initial visual acuity. A final visual acuity less than or equal to 20/200 was recorded in 57 of 61 (93%) of ischemic eyes and 53 of 107 (50%) of nonischemic eyes
The British National Insurance Act

I. General significance, 275. — II. Sickness and Disablement Insurance, 280. — Number and kind of persons insured, 281. — Tripartite source of contributions, 284. — Character of workmen's contribution, 285.— The kinds of benefit, 287.— Administration by "approved societies," 289. — "Deposit contributors," 294. — Insurance Committees and the doctor situation, 295. — National administration, 297. — III. Unemployment Insurance, 298. — The innovation of compulsion, 299. — Character of contributions, 300.— Administration, 301.— Constructive arrangements, 302.— Trade unions and voluntary provisions, 304. — IV. Ulterior effects, 305. — Economy and rising costs, 305. — Is an increasing sickness rate a sign of inefficiency? 307. — Effect on births, 309. — The minimum wage principle and its effects, 310. — The moral potency of risk and insurance, 311.
Infrared spectroscopy of bare single crystal and nano-particle covered surfaces

Infrared spectroelectrochemistry is the leading technique for in situ investigation of electrode - solution interfaces because it can both identify the species adsorbed at the metal/solution interface, and quantitatively follow their reaction and kinetic behavior. The unique capabilities of the method have been demonstrated by selective examples, including the identification of preferentially adsorbed species on single crystal surfaces of noble metals with hexagonal symmetry, and electrochemical oxidation of CO on bare and Pt-decorated single crystal Ru surfaces.
Birth defects monitoring in California: a resource for epidemiological research.

Summary. The California Birth Defects Monitoring Program maintains a population-based birth defects registry of structural congenital malformations, monitoring over 600000 resident births annually. Cases are actively ascertained from hospitals and genetic centres throughout California and from selected facilities in adjacent states. Field staff identify presumptive cases from careful review of medical records. Diagnostic and demographic information is collected from in-patient and genetic centre medical charts for children diagnosed with major structural malformations between conception and 1 year of age. The application of these data to epidemiological investigations of birth defects is described in the context of prevalence studies, aetiological studies and evaluative studies, and the strengths and limitations of the registry data are discussed.
The Riemann integrable functions are Π30-complete in the Lebesgue integrable functions

Abstract The subset of Riemann integrable functions in L 1 [ 0 , 1 ] is a Borel set which is Π 3 0 -complete, i.e. F σ δ but not G δ σ .
Trabalho e acidentes no meio rural do Oeste Catarinense - Santa Catarina, Brasil

The aim of the present study was to check the characteristics of agricultural workers and the incidence of work-related accidents in the west of Santa Catarina, Brazil. Sixty patterned questionnaires were used, and data on sociodemographics, work, and workplace accidents were collected. The percentage of household heads aged between 41 and 60 years amounted to 60% and that of married ones totaled 68.3%, with average school attendance between 4 and 8 years; 97% were landowners, among whom 83.3% owned more than 8 hectares. The average weekly workload of 80% of agricultural workers exceeds 40 hours, with a 20% incidence of workplace accidents. These data show the variety of activities and occupational hazards and point out an urgent need for public health surveillance, since accidents involving agricultural workers usually do not appear in the official statistics and still have to be addressed by Brazilian social policies.
Nuclear Oncology 1984

New developments in nuclear oncology, based on monoclonal antibodies and position emission tomography measurement of glucose metabolism promise to broaden the range of applications of nuclear medicine methods in the clinical management of patients with tumor. Perhaps of greatest importance, is the prospect of both diagnosing and treating common solid tumors, with the same radiolabeled (monoclonal antibody) pharmaceutical preparation.
In-Situ Measurements of Water Transfer Due to Different Mechanisms in a PEM Fuel Cell

Water management is of critical importance in a proton exchange membrane (PEM) fuel cell. Yet there are very limited studies of water transfer through the membrane and no data are available for water transfer due to individual mechanisms through the membrane electrode assembly (MEA) in an operational fuel cell. Thus it is the objective of this study to measure water transfer through the MEA due to different mechanisms through the membrane electrode assembly (MEA) of an operational PEM fuel cell. The three different mechanisms of water transfer, i.e., electro-osmotic drag, diffusion and hydraulic permeation were isolated by specially imposed boundary conditions. Therefore water transfer through the MEA due to each mechanism could be measured separately. In this study, all the data were collected in an actual assembled operational fuel cell, and some of the data were collected while the fuel cell was generating power. The measured results showed that water transfer due to hydraulic permeation, i.e. the pressure difference between the anode and cathode is at least an order of magnitude lower than those due to other two mechanisms. The data for water transfers due to electro-osmosis and diffusion through the MEA are in good agreement with some of the data and model predications in the literature for the membrane. The methodology used in this study is simple and can be easily adopted for in-situ water transfer measurement due to different mechanisms in actual PEM fuel cells without any cell modifications.Copyright © 2007 by ASME
Semiautomated analysis of retinal vessel diameter in retinopathy of prematurity patients with and without plus disease.

Purpose To determine the feasibility of using semiautomated analysis of digital fundus images to quantify the differences in retinal vascular diameter between retinopathy of prematurity (ROP) patients with and without plus disease. Design Case-control study. Methods Thirty eyes of 15 patients with ROP were included in this study. Fourteen eyes of seven patients had plus disease and 16 eyes of eight patients had no evidence of plus disease. Digital fundus images were captured using an NM200D (Nidek, Inc, Aichi, Japan) camera. Vessel diameters were determined using VesselMap software (Imedos, Jena, Germany). The Student t test analysis was used to compare diameters of vessels with and without plus disease. Results We found that the average venous diameter is significantly larger by 15% in the group with plus disease. Conclusions VesselMap analysis of digital images is feasible. This method is able to distinguish between veins with and without plus disease, and may be useful in telemedicine screening strategies.
Modeling of electromagnetic brakes for enhanced braking capabilities

In automatic highway systems, automatic brake actuation is a very important part of the overall control of the vehicle. Hence, a faster response and a robust braking system are crucial. This paper describes electromagnetic brakes as a supplementary system for regular friction brakes. This system provides better response time for emergency situations, and in general keeps the friction brake working longer and safer. A new mathematical model for electromagnetic brakes is proposed to describe their static characteristics. The performance of the new mathematical model is better than the other three models available in the literature.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Many-electron effects on transport processes in dense helium

Many-electron effects on dynamical correlations in dense helium are studied by means of self-consistent-field molecular dynamics, a computational method that combines a Hartree-Fock solution of the electronic structure of an arbitrary collection of atoms with molecular dynamics. Pair correlation functions, velocity autocorrelation functions, and coefficients of self-diffusion are calculated for helium at densities between 0.1 and 1.5 g/cm{sup 3} and at temperatures of 1 and 5 eV. Comparisons are made to results computed with semiempirical pair potentials derived from low- and high-density experimental data. With increasing density, the self-consistent-field molecular-dynamics results progressively diverge from the results of molecular-dynamics simulations using Hartree-Fock pair potentials, reflecting the onset of many-atom screening effects within local clusters of atoms. This dynamic screening results in a 30% increase in the diffusion coefficient over that obtained in a molecular-dynamics simulation employing pair interaction potentials.
Pigment Epithelium-Derived Factor Inhibits Retinal and Choroidal Neovascularization

In this study, we investigated whether overexpression of pigment epithelium-derived factor (PEDF) by gene transfer can inhibit neovascularization by testing its effect in three different models of ocular neovascularization. Intravitreous injection of an adenoviral vector encoding PEDF resulted in expression of PEDF mRNA in the eye measured by RT-PCR and increased immunohistochemical staining for PEDF protein throughout the retina. In mice with laser-induced rupture of Bruch's membrane, choroidal neovascularization was significantly reduced after intravitreous injection of PEDF vector compared to injection of null vector or no injection. Subretinal injection of the PEDF vector resulted in prominent staining for PEDF in retinal pigmented epithelial cells and strong inhibition of choroidal neovascularization. In two models of retinal neovascularization (transgenic mice with increased expression of vascular endothelial growth factor (VEGF) in photoreceptors and mice with oxygen-induced ischemic retinopathy), intravitreous injection of null vector resulted in decreased neovascularization compared to no injection, but intravitreous injection of PEDF vector resulted in further inhibition of neovascularization that was statistically significant. These data suggest that sustained increased intraocular expression of PEDF by gene therapy might provide a promising approach for treatment of ocular neovascularization.
Errors in measurement of the P-R (P-Q) interval and QRS duration in the electrocardiogram

Abstract 1. 1. We have discovered errors in existing methods of measurement of the P-R interval and QRS duration in the electrocardiogram. 2. 2. These errors are usually the result of balancing of similar deflections of opposite direction in Leads I and III, producing isoelectric phases in Lead II. Lead II, therefore, is often the least reliable for the measurement of electrocardiographic time intervals. 3. 3. Such variations were found to occur in 3.8 per cent of 1000 consecutive cases. 4. 4. It is pointed out that the variations may be of considerable individual significance diagnostically, and may be of statistical importance from the standpoint of existing accepted values for normal limits of the P-R interval and QRS duration. 5. 5. A simple method of avoiding the errors is presented. In general, Lead III has been found to be the most reliable single lead for the measurement of time intervals.
SENSITIVITY ANALYSIS AND OPTIMIZATION OF COUPLED THERMAL AND FLOW PROBLEMS WITH APPLICATIONS TO CONTRACTION DESIGN

The finite element method and the Newton–Raphson solution algorithm are combined to solve the momentum, mass and energy conservation equations for coupled flow problems. Design sensitivities for a generalised response function with respect to design parameters which describe shape, material property and load data are evaluated via the direct differentiation method. The efficiently computed sensitivities are verified by comparison with computationally intensive, finite difference sensitivity approximations. The design sensitivities are then used in a numerical optimization algorithm to minimize the pressure drop in flow through contractions. Both laminar and turbulent flows are considered. In the turbulent flow problems the time-averaged momentum and mass conservati on equations are solved using a mixing length turbulence model.
Efficient variable elimination for semi-structured simple temporal networks with continuous domains

The Simple Temporal Network (STN) is a widely used framework for reasoning about quantitative temporal constraints over variables with continuous or discrete domains. The inference tasks of determining consistency and deriving the minimal network are traditionally achieved by graph algorithms (e.g. Floyd-Warshall, Johnson) or by iteration of narrowing operators (e.g. ΔSTP). None of these methods exploits effectively the tree-decomposition structure of the constraint graph of an STN. Methods based on variable elimination (e.g. adaptive consistency) can exploit this structure, but have not been applied to STNs as far as they could, in part because it is unclear how to efficiently pass the ‘messages’ over continuous domains. We show that for an STN, these messages can be represented compactly as sub-STNs. We then present an efficient message-passing scheme for computing the minimal constraints of an STN. Analysis of this algorithm, Prop-STP, brings formal explanation of the performance of the existing STN solvers ΔSTP and SR-PC. Empirical results validate the efficiency of Prop-STP, demonstrating performance comparable to ΔSTP, in cases where the constraint graph is known to have small tree width, such as those that arise during Hierarchical Task Network planning.
Effects of initial soil calcium content on ammonia losses from surface-applied urea and calcium-urea

Ammonia loss from surface-applied urea occurs because urea hydrolysis increases the pH of the placement site microenvironment. Addition of Ca-salts with urea will control or reduce the microsite pH, thus reducing NH3 losses. The degree of Ca-saturation of the cation exchange sites may influence the ratio of calcium:urea required to control ammonia loss. A laboratory study was conducted to determine if adsorbed Ca or CaCO3 additions (acid soils only) had a measureable impact on Ca control of NH3 loss from surface applied urea at various Ca:urea ratios.
The Effects of Emergent Norms and Attitudes on Recycling Behavior

Residence hall residents indicated their attitudes about recycling and their perceptions of whether friends and family believed they should recycle at the beginning and toward the end of a semester. They also reported their recycling behavior at the end of the semester. Attitudes, but not subjective norms, predicted behavior, and participants became more similar to their fellow group members in attitudes and behavior over time. Attitudes and fellow group member behavior best predicted recycling, supporting the theory of reasoned action, dynamic social impact theory, and their integration.
Acute appendicitis--not just for the young.

Abstract Background The incidence of appendicitis is highest in young patients, but the number of elderly patients with appendicitis appears to be increasing. The authors evaluated a statewide experience to assess the effect of age on resource utilization and outcomes for this common disease. Methods All discharges from Kentucky hospitals for appendicitis were identified. Patients from rehabilitation hospitals, those with inflammatory bowel disease, and those undergoing incidental appendectomy were excluded. Results Young (aged ≤ 29 years) and middle-aged (aged 30–64 years) patients each constituted 45% of all patients with appendicitis. Length of stay, hospital charges, and frequency of complicated appendicitis all increased with age. Although elderly patients (aged ≥ 80 years) underwent laparoscopic appendectomy as frequently (60%) as younger patients, they were more likely to undergo complicated open procedures. Conclusions Older patients represent a substantial population of patients with appendicitis, with more complicated operative procedures, increased lengths of stay, and increased resource utilization.
The thermal neutron fission cross-section of 10·1 hr 244Am

Abstract The thermal neutron fission cross-section of the 10·1 hr isomer of 244Am has been determined by counting fissions induced by neutrons in the thermal column of the Argonne reactor CP-5. A decrease in fissionability with the characteristic 10·1 hr half-life was observed. The fission cross-section of 2300 ± 300 barns was obtained by comparing the fission counting rate of 244Am with that of a 233U standard.
Children's Initial Assumptions about the Meaning of Novel Motion Verbs: Biased and Conservative?.

This study examined the role that changes in continuity, direction, instrument, and causative agent play in children's and adults' initial assumptions about the meaning of novel motion verbs and events. Three-year-olds, 7-year-olds, and adults were shown novel videotaped motions in a verb label or a no verb label condition. Subjects were then asked whether these exemplars generalized to events in which only one of the previously mentioned components had been changed. Overall, subjects made strikingly similar initial assumptions: Causative agent changes rendered all subjects least likely to generalize the novel verbs and events, and generalizations were virtually unaffected by whether the events were labeled or unlabeled by a novel verb. However, children generalized more conservatively than adults to all change types in general, and to instrument changes in particular. In this article similarities in generalizations are interpreted in terms of direct mapping and a causative agent bias. Finally, we discuss children's comparative conservatism and alternative depictions of constraints on verb learning.
Will you be my friend?: responses to friendship requests from strangers

A malicious person could access a wealth of one's personal information by being one's 'friend' on a social networking site. The goal of this research is to understand the extent to which users are vulnerable to this tactic. Our experiment examined responses of users of a social networking site to a friendship request from a total stranger. Preliminary results indicate that a small but significant percentage of individuals are open to accepting such requests. The tendency to accept was higher when the request came from an unattractive person of the opposite sex. In the case of same-gender connections, however, the likelihood of acceptance was higher for attractive requesters. Moreover, the mere presence of a profile photo, regardless of gender and attractiveness of the requester, greatly increased the likelihood of request acceptance. However, individuals with higher privacy concerns showed a greater tendency to decline the request.
Musculoskeletal Complaints and Serum Autoantibodies Associated with Chronic Hepatitis C and Nonalcoholic Fatty Liver Disease

We sought to compare the musculoskeletal symptoms and immune markers found in chronic hepatitis C (HCV) and nonalcoholic fatty liver disease (NAFLD). Patients with HCV or NAFLD answered a questionnaire and donated serum for autoantibody testing. Univariate analysis between the HCV and NAFLD groups revealed joint pain in 67% of the HCV group and 65% of the NAFLD group. Those with joint pain reported inflammatory characteristics that were similar between the groups. The presence of a positive rheumatoid factor and cryoglobulins was higher in the HCV group, however both groups had a similar prevalence of a low positive antinuclear antibody (ANA). We conclude that the NAFLD group reported a higher amount of joint pain and inflammatory joint symptoms than anticipated. We were unable to determine a variable that predicted the presence of joint pain. Therefore, more investigation is needed to determine whether these findings are due to liver disease alone.
Estimating the Severity of Shaft Vibrations Within Fluid Film Journal Bearings

Proximity probes are being widely used in turbomachinery to measure the amplitude of shaft vibrations within fluid film bearings. There has been, however, little information available for judging the degree of severity of such vibrations. The present paper provides an analysis which correlates shaft vibration amplitude with some basic bearing parameters—allowable dynamic load on the bearing, its size, geometry, and operating conditions. Curves are provided for several bearing geometries which can be used for a rational estimate of allowable shaft vibration levels.
TRUTHS AND ANSWERS

problems associated with the analysis of gain scores, residual scores, and repeated measures for individuals is clear and logical. However, his choice of ACT's COMP Objective Test to illustrate his argument is misleading. ACT formally notified Pike and his colleagues of the inappropriate analysis of data based on this test in Fall 1989 (Steele, 1989c). At that time some of the same problems he discusses in his article were pointed out as leading him to incorrect results and unwarranted generalizations. Unworthy uses of tests should not be used to judge the technical merits of those tests. The Standards for Educational and Psychological Testing (AERA, APA, and NCME, 1985) make clear that validity is not a characteristic of an instrument per se but "refers to the appropriateness, meaningf ulness, and usefulness of the specific inferences made from test scores" (p. 9). Pike claims inaccurately that, "Gain scores are reported by the College Outcome Measures Program (COMP) staff as indicators of student learning and program effectiveness" (p. 72). In fact, ACT has always recommended mean score gains, not individual gain scores, as indicators of program effectiveness. In addition, ACT has always clearly stated that the COMP Objective Test should not be used in making judgments about individual students but should be analyzed with the group as the unit of analysis as an indicator of program quality and effectiveness (Steele, 1989b). The merit of the COMP Objective Test can be judged against accepted technical standards, based on its intended uses. The worth of the Objective Test depends on actual uses that do not undermine the construct validity of the instrument and represent well-designed evaluation efforts (Scriven, 1981). Pike describes results from his unworthy use of the test to question its technical merit. In contrast to the somewhat meaningless results based on his use and
Comparison of the Composition and Temperature Dependences of Segmental and Terminal Dynamics in Polybutadiene/Poly(vinyl ethylene) Blends

13C NMR relaxation measurements were performed on two series of miscible polymer blends: entangled polybutadiene (PB) in perdeuterated oligomeric poly(vinyl ethylene) and entangled poly(vinyl ethylene) (PVE) in perdeuterated oligomeric polybutadiene. A wide range of temperatures (∼ Tg + 50 K to Tg + 200 K) and several compositions (weight fractions of 0, 0.25, 0.5, 0.75, 1) were investigated. The segmental correlation times for the entangled components in both series of blends were extracted and compared to the corresponding terminal dynamics reported by Yang et al. The terminal dynamics have a stronger composition dependence than the segmental dynamics in PB/PVE blends. In contrast, a previous study of polyisoprene/poly(vinyl ethylene) blends revealed that the segmental and terminal dynamics exhibit equivalent dependences on the temperature and composition in that system. The Lodge/McLeish model satisfactorily fits the segmental correlation times in PB/PVE blends, but with the fit parameter φself differ...
Transition between viscous and inertial-range scaling of turbulence structure functions

The transition of velocity structure functions between the viscous and inertial range is examined by assuming a plausible interpolation formula for the required scaling functions. This analysis shows that the recently observed phenomenon of extended self-similarity (ESS) is consistent with assuming that the cutoff length decreases with increasing order of the moment. A revised multifractal formalism is used to quantify this dependence of cutoff scale on the order of the moment. At low and intermediate Reynolds numbers, the proposed mechanism predicts ESS, as well as some additional subtle trends that are experimentally observed. However, at large Reynolds numbers, the shift in cutoff scale predicted by the multifractal formalism becomes too large to be consistent with ESS. \textcopyright{} 1996 The American Physical Society.
Germination and Early Growth of Grasses in Controlled Conditions

Widespread interest in the development and selection of both native and introduced plants for the control of soil erosion, the improvement of vegetation cover in grazing areas, and the maximum utilization of land devoted to agriculture and horticulture has focused attention on the need for basic physiological studies that relate to the survival, growth, and development of different species and races in different kinds of climate. This field of study, which of necessity embraces an appraisal and integration of genetical, physiological, and ecological factors, is so complex that to date satisfactory experimental approaches have not yet been developed. With the completion of the Earhart Laboratory at the California Institute of Technology at Pasadena, a new instrument especially useful for the resolution of such complex relationships is now available, for it makes possible for the first time critical studies on the growth of plants on a relatively large scale under known controlled external conditions (Went 1949). The present study on the germination and early development of several species of grasses, mostly of the genus Poa, was conducted in the Earhart Laboratory during the summer and fall of 1950. One objective was to compare the germination and early seedling development of various species and species-hybrids at different ranges of temperature. This is of practical significance in planning reseeding programs on burned or denuded areas in arid Southern California where the establishment of young seedlings is limited to the cool winter months when rains occur. Night temperatures may then be close to freezing even at medium altitudes. Another objective was to provide background information for a broad study of physiological characteristics of importance to the establishment and survival of plants generally in different kinds of environment. The strains of Poa and Poa hybrids used in this investigation are also being currently tested in widespread field plantings by the U. S. Soil Conservation Service, the U. S. Forest Service, and the Carnegie Institution of Washington. Certain strains of Poa reproduce largely by apomixis (cf Mfintzing 1933, Akerberg 1942, Clausen, Keck, and Hiesey 1947), and these are especially well-suited to comparative studies because the same clone can be conveniently grown from seed under different sets of controlled environments simultaneously. Moreover, data from different types of experiments, such as those from laboratory and field tests, can likewise be compared for the same genetic strain. The wide diversity of genetic strains in Poa includes species and races suited to a great range of contrasting climates. Data accumulated over a period of time on different clones of known genetic composition should ultimately provide basic information from which predictions on many aspects of field performance may be made with reasonable certainty on the basis of a few well-chosen laboratory experiments.