cssi/SciSciGPT-SciSciNet huggingface dataset:
Electron Drift Velocities in Liquefied Argon and Krypton at Low Electric Field Strengths

In this paper we report measurements of the drift velocity of electrons in liquid Ar and Kr as a function of temperature, pressure, and electric field strength. The experimental findings are as follows: (a) At low temperatures (115\ifmmode^\circ\else\textdegree\fi{}K) in liquid Ar, the mobility of the electron (\ensuremath{\sim}400 ${\mathrm{cm}}^{2}$ ${\mathrm{V}}^{\ensuremath{-}1}$ ${\mathrm{sec}}^{\ensuremath{-}1}$) decreases with increasing temperature and increases with increasing pressure. In this region the electron drift velocity is linear in the electric field strength (from -100 to -200 V/cm). (b) At high temperatures (g115\ifmmode^\circ\else\textdegree\fi{}K) in liquid Ar and at all temperatures in liquid Kr the electron drift velocity (4-20\ifmmode\times\else\texttimes\fi{}${10}^{4}$ cm/sec) at electric field strengths from -50 to -150 V/cm increases with increasing temperature. There may be a maximum in the electron drift velocity-temperature profile of liquid Kr. In this region the drift velocity is not linear in the electric field strength. It is demonstrated that an elementary scattering theory (with several variants for the scattering cross section) provides a reasonable zeroth-order description of the electron mobility in liquid Ar in the low-field, low-temperature (115\ifmmode^\circ\else\textdegree\fi{}K) region. The theory incorporates the effects of coherence in the electron scattering from nearby atoms into the cross section of a modified Boltzmann equation. The magnitude of the mobility and the pressure and temperature dependence (85-115\ifmmode^\circ\else\textdegree\fi{}K in liquid Ar) of the mobility are all reproduced to better than a factor of 2. It is found that the electron velocity distribution is not thermal and that the mean electron energy may be as large as 0.5 eV, even when the electric-field strength is as low as 100 V/cm. By numerical calculation based on the elementary scattering theory, we find the onset of nonlinearity in the electric-field dependence of the electron drift velocity at $E\ensuremath{\approx}1$ V ${\mathrm{cm}}^{\ensuremath{-}1}$ in disagreement with the experimental findings described in (a). The anomalous rise of the drift velocity per unit field in liquid Ar above 115\ifmmode^\circ\else\textdegree\fi{}K, and at all temperatures in liquid Kr, intuitively suggests that there may be a Ramsauer minimum in the effective electron-atom scattering cross section in the liquid. Within the framework of the elementary theories considered, we have, at present, no explanation for the anomalous temperature dependence of the electron drift velocity in liquefied Ar and Kr.
Analysis of Fiber Optic Sensor to Measure Velocity During Electromagnetic Forming and Welding

Previous methods of measuring high velocity deformation in electromagnetic forming and magnetic pulse welding include Photon Doppler Velocimetry (PDV), laser micrometers, and high speed photography. In this paper an alternative method is presented, implementing a fiber optic, reflectance dependent displacement sensor. The sensor is shown to be an attractive low cost solution to measurement of high velocities in high voltage, magnetic environments. Data is shown with respect to sensor characterization including various surface reflectivity values, curvatures, and misalignments; implementation in two forming and welding processes; and verification with high velocity measurement in parallel with PDV. The sensor system is one twentieth the cost of a PDV system, and yet measures velocities accurately to at least 140 m/s. Sensor performance is also enhanced by the use of retroreflective tape, which is shown to increase the displacement range by 9×, decrease sensitivity to misalignment, and increase repeatability and ease of implementation.© 2013 ASME
Potential problems and solutions when hiring and training a worldwide sales team

In today’s global economy, increasing numbers of companies are entering the international marketplace. The quality of managerial actions in salesforce hiring and training greatly influences the overall success of the firm. Although most companies attempt to select and train the most appropriate global salespersons, mistakes are difficult to repair and can lead to business failure. Examines selection and training procedures in a global environment, discusses specific problem situations encountered in the field by the authors, and provides guidance to assist sales managers make more successful hiring and training decisions for their worldwide sales team.
Alloying effects on the microstructure and phase stability of Fe–Cr–Mn steels

Austenitic Fe–Cr–Mn stainless steels interstitially alloyed with nitrogen have received considerable interest lately, due to their many property improvements over conventional Fe–Cr–Ni alloys. The addition of nitrogen to Fe–Cr–Mn stabilizes the fcc structure and increases the carbon solubility. The benefits of increased interstitial nitrogen and carbon content include: enhanced strength, hardness, and wear resistance. This study examines the effect of carbon, silicon, molybdenum, and nickel additions on the phase stability and tensile behavior of nitrogen-containing Fe–Cr–Mn alloys. Nitrogen and carbon concentrations exceeding 2.0 wt.% were added to the base Fe–18Cr–18Mn composition without the formation of nitride or carbide precipitates. Minor additions of molybdenum, silicon, and nickel did not affect nitrogen interstitial solubility, but did reduce carbon solubility resulting in the formation of M23C6 (M=Cr, Fe, Mo) carbides. Increasing the interstitial content increases the lattice distortion strain, which is directly correlated with an increase in yield stress.
The Structure of Aquifex aeolicus Ribosomal Protein S8 Reveals a Unique Subdomain that Contributes to an Extremely Tight Association with 16S rRNA

The assembly of ribonucleoprotein complexes occurs under a broad range of conditions, but the principles that promote assembly and allow function at high temperature are poorly understood. The ribosomal protein S8 from Aquifex aeolicus (AS8) is unique in that there is a 41-residue insertion in the consensus S8 sequence. In addition, AS8 exhibits an unusually high affinity for the 16S ribosomal RNA, characterized by a picomolar dissociation constant that is approximately 26,000-fold tighter than the equivalent interaction from Escherichia coli. Deletion analysis demonstrated that binding to the minimal site on helix 21 occurred at the same nanomolar affinity found for other bacterial species. The additional affinity required the presence of a three-helix junction between helices 20, 21, and 22. The crystal structure of AS8 was solved, revealing the helix–loop–helix geometry of the unique AS8 insertion region, while the core of the molecule is conserved with known S8 structures. The AS8 structure was modeled onto the structure of the 30S ribosomal subunit from E. coli, suggesting the possibility that the unique subdomain provides additional backbone and side-chain contacts between the protein and an unpaired base within the three-way junction of helices 20, 21, and 22. Point mutations in the protein insertion subdomain resulted in a significantly reduced RNA binding affinity with respect to wild-type AS8. These results indicate that the AS8-specific subdomain provides additional interactions with the three-way junction that contribute to the extremely tight binding to ribosomal RNA.
Direct optical phase shifter for phased-array systems

An all optical circuit in GaAs/AlGaAs for control of phased-array systems using a single photonic integrated circuit chip has the potential for high performance control of phased-array system from a small, lightweight, package. Such a circuit based exclusively on combinations of reverse-biased optical phase modulators, waveguide interconnects, corner reflectors, and power splitter combiners with optical-fiber output to the antenna elements has been designed at Sandia National Laboratories. This paper presents some basic features of optical phase modulators for photonic circuit applications and provide relevant performance data as achieved to date. Current structures have been shown to operate with a 76.5 degree/V-mm figure of merit at 1.06 micron and losses as low as 2/cm. A digital phase shifter to allow direct digital control of phased arrays is also proposed and demonstrated.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Deuterium-isotope effect in the biotransformation of 4-ethynylbiphenyls to 4-biphenylylacetic acids by rat hepatic microsomes

Abstract In vitro studies using hepatic microsomal homogenate and 4-(1-deuteroethynyl) biphenyls have shown that there is an isotope effect in conversion of 4-ethynylbiphenyls to 4-biphenylylacetic acids. This effect is consistent with mechanisms involving either (1) direct hydroxylation of the ethynyl moiety or (2) oxirene formation followed by a rate-determining hydride shift to form the intermediate ketene.
Analytical investigation of pile-soil interaction in sand under axial and lateral loads

This paper presents a numerical study of pile- soil interaction due to application of axial and lateral loads to piles in sand. The pile-soil interaction was analyzed using the finite difference (FD) software LPILE and two finite element (FE) software. The three-dimensional (3D) FE models of pile-soil interaction have been created using Abaqus/Cae and SAP2000. Various types of soft soil were studied, such as loose, medium, and dense sand. A lateral displacement of 2 cm was applied to the top of the pile while maintaining a zero slope in a guided fixation. A combined lateral and axial load of 300 kN was also stud- ied. The paper compared between the bending moments and lateral displacements along the depth of the pile obtained from the FD solutions and FE analyses. A para- metric study was conducted to study the effect of crucial design parameters such as the modulus of elasticity of soil and the number of nonlinear soil springs that can be used to model the soil. A good agreement between the results obtained by the FE models and the FD solution was observed. Also, the FE models were capable of predicting the pile-soil interaction for all types of soft soil.
John Locke, the individual, and the origin of communication

Communication is a product of a particular historical epoch and set of social conditions. The concept emerges in classic liberalism and presupposes a society in which individuals are thought of as free from external constraints of society, others, history, and language, and are seen as holders of private property in both material goods and consciousness. John Locke's linguistic and political theories illustrate the birth of communication and the conditions and commitments that accompany that term in contemporary theory and society.
THE CRUSTACEAN MYOCHORDOTONAL ORGAN AS A PROPRIOCEPTIVE SYSTEM.

Abstract 1. 1. In the meropodite of the walking legs of the crab Cancer magister Dana, the myochordotonal organ system consists of a specialized receptor muscle with associated elastic strands and a group of approximately forty bipolar neurons. This system provides proprioceptive information about action of the mero-carpopodite (MC) joint. The 6 mm length change in the receptor muscle caused by full joint movement is reduced 22 : 1 at the site of the sensory neurons by the elaborate mechanical suspension of the system. 2. 2. Electrophysiological recording from the sensory neurons discloses (1) movement receptors active during joint displacement and (2) position receptors which are sensitive to different static positions and relatively insensitive to the phasic component of joint action. The movement receptors are unidirectional with a given receptor responding to either flexion or extension of the MC joint. A single movement receptor responds only over a fraction of the full joint range and the composite input from many different receptors is required to cover the complete joint movement. Movement receptors increase their discharge rate with increasing velocity of joint movement. 3. 3. The position receptors fire at a different average frequency for each static position. A single unit also responds only over a fraction of the full joint range. 4. 4. Direct stretching or relaxation of the accessory flexor muscle can mimic the response of the sense cells evoked by activity of the MC joint. The accessory flexor muscle serves primarily a sensory role analogous to the intrafusal muscle fibers of the vertebrate muscle spindle.
In search of the exchange risk premium: A six-currency test assuming mean-variance optimization

Abstract A number of authors, examining deviations of actual rates of currency depreciation from forward discounts, have claimed to find evidence of risk premiums. If these deviations are indeed partly due to risk premiums, rather than being entirely due to expectational errors, then they should be systematically related to those variables on which risk premiums are thought to depend. Finance theory tells us that if investors optimize with respect to mean and variance, the risk premium depends in a specific way on (1) the supplies of assets denominated in the various currencies, (2) the variance-covariance matrix of the rates of return, and (3) the coefficient of risk-aversion. The null hypothesis of this paper is that the coefficient of risk-aversion is zero, countries' assets are perfect substitutes, and risk premiums are nonexistent. The alternative hypothesis is that rates of return are systematically related to asset supplies by a macroeconomic portfolio-balance function. The maximum likelihood technique used dominates previous attempts to find such a relationship in that the parameters of the portfolio-balance function are constrained to depend on the variance-covariance matrix as the finance theory says they should. On the other hand, the technique also dominates previous applications of the finance theory in that the expected returns are allowed to vary over time, as the macroeconomic portfolio-balance theory says they should. The paper's finding is a statistical inability to reject the null hypothesis for a portfolio of six currencies, although this could be due to low power in the test.
THE MEASUREMENT OF BODY VOLUME IN PRETERM INFANTS BY ACOUSTIC PLETHYSMOGRAPHY

An accurate measurement of body volume is essential when body protein and fat are estimated by the densitometric method expanded to a four compartment system: total body water, protein, fat, and mineral. Total body fat and lean body mass comprise the usual two compartment system. The acoustic plethysmograph, based on the Helmholtz resonator principle, was tested with miniature pigs. Body volume was estimated with a reproducibility of 2.5% and no differences were noted between volumes estimated by that method and water displacement. That initial prototype was affected significantly by temperature; a 1° deviation at 35° C resulted in a 2.5% change in body volume estimates. A constant temperature chamber has been designed. The body volume of 8 preterm infants (postnatal age and body weight ranges were 2.5 - 11 wks and 1423 - 2425 g, respectively) was measured. Ten measurements, each of 1 min duration, were obtained on each subject. The mean coefficient of variation of the measurements was 1.43 ± 0.55%. Body volumes and densities ranged from 1382 - 2450 cc and 0.97 - 1.067 g/cc (mean = 1.028 ± 0.024 g/cc), respectively. The reproducibility also was tested from measurements obtained on the same infants on two consecutive days. The mean difference between measurements was 0.7 ± 0.6%. This method is rapid, noninvasive, has a low coefficient of variation, and is ideal to measure the body volumes of infants.
π−π Interactions and Solid State Packing Trends of Polycyclic Aromatic Bowls in the Indenocorannulene Family: Predicting Potentially Useful Bulk Properties

Solid state crystal structures are discussed and compared for all seven members of the indenocorannulene family that have been recently synthesized by iterative microwave-assisted intramolecular arylations and characterized by single crystal X-ray diffraction. These bowl-shaped polyaromatic hydrocarbons include monoindenocorannulene (C26H12), two isomers each of diindenocorannulene (C32H14) and triindenocorannulene (C38H16), tetraindenocorannulene (C44H18), and pentaindenocorannulene (C50H20), with all molecules mapping onto the geodesic framework of the C60-fullerene. This extended family of π-bowls represents a unique case of a stepwise build-up of size, curvature, and strain at the corannulene core. It allows the first evaluation of the effects of controlled extension of nonplanar π-aromatic surfaces on the solid state structures of the resulting crystalline solids. First, a face-to-face π−π alignment of individual bowls to form 1D stacks is considered and compared for all the above indenocorannulenes ...
Hypokalemia and electrocardiographic abnormalities during acute alcohol withdrawal.

THE SYNDROMES of acute alcohol withdrawal have been well defined, 1 but despite a large number of patients, relatively little is known of the metabolic changes accompanying withdrawal. Abnormalities in electrolyte metabolism during this acute phase have been reported, 2-4 but few prospective studies have been carried out. However, it has been reported that no significant alteration occurs in the serum electrolytes of normal volunteers during recovery from ingestion of large quantities of alcohol 5,6 ; in addition, no abnormalities were observed in a small series of chronic alcoholic patients. 7 During observation and evaluation of chronic alcoholic patients undergoing withdrawal at San Francisco General Hospital it was noted that the levels of serum potassium were frequently low and that cardiac arrhythmias and alterations in the ST segment, T, and U waves in the electrocardiograms were common. Consequently, a study was undertaken to determine the frequency and severity of hypokalemia
Utilization of research findings and databases for serendipitous technology transfer

Abstract Information collected from previous research studies can be used to address problems which were totally unrelated at the time the original research was planned and conducted. Evaluation of existing databases for extended uses can lead to valuable applications when used with modern computer-based modeling techniques. An example drawn from 1992 cereal rust survey and U.S. climatological data is presented to illustrate one type of application for databases from diverse sources. Cereal rust epidemiology data from several years of rust surveys can be blended with climatological data, cultivar distribution data, and rust loss information to develop a program to predict rust epidemics. These data from past years can also be used to determine the conditions which lead to cereal rust development and spread which contributed to subsequent losses in yield and quality. This information can then be used to develop a predictive model to provide agricultural industry managers and growers with advanced warnings of epidemics.
Reaction of some group VI elements, oxide and uranium with chlorine-hydrogen fluoride mixtures

Abstract When group VI elements and uranium were reacted with chlorine-hydrogen fluoride mixtures, good yields of WF 6 were found in the case of W, while only MoF 5 , Mo V chlorofluorides, and a spectroscopic trace of MoF 6 were found when the element was Mo. Uranium gives UF 4 at lower temparatures whereas at higher temperatures U 2 F 9 and a spectroscopically-detected UF 6 were found. The reaction with SOF 2 always results in SO 2 F. At higher temperatures SF 6 could be detected by spectroscopic means but not isolated. The predominant product with Se is SeCl 4 . When WO 3 is reacted an oxyfluoride is formed.
23 Mobile Things: self-directed and effective professional learning

Purpose – The purpose of this paper is to examine the “Mobile 23 Things” survey results from the program offered by Guldborgsund-bibliotekerne (a public library in Denmark) and present the findings as support for professional development (PD) models to increase library staff familiarity with emerging technologies. Design/methodology/approach – Using an integrated, exploratory approach, a web-based survey tool, developed for a previous Learning 2.0 study, was adapted for this study, with survey questions translated English – Danish, and responses Danish – English. The data gathered from both pre- and post-program surveys are presented and analyzed. Findings – The research results identify that 23 Mobile Things increases familiarity with movable technologies, promotes inclusive learning, and can be an effective model for delivering PD. Originality/value – This paper reports on the first research study to evaluate the 23 Mobile Things model and provides evidence that this model of library staff PD can be an ...
The Neglect of Purkinje's Technique of Ophtha-lmoscopy Prior to Helmholtz's Invention of the Ophthalmoscope

A technique for examining the fundus of the eye was devised by Jan Evangelista Purkinje a generation before Helmholtz invented the ophthalmoscope. Yet, Purkinje's technique of ophthalmoscopy went virtually unnoticed by his contemporaries. This neglect of Purkinje's discovery has never been fully explained and warrants re-examination.
Fabrication of polymer electrolyte membrane fuel cell MEAs utilizing inkjet print technology

Abstract Utilizing drop-on-demand technology, we have successfully fabricated hydrogen–air polymer electrolyte membrane fuel cells (PEMFC), demonstrated some of the processing advantages of this technology and have demonstrated that the performance is comparable to conventionally fabricated membrane electrode assemblies (MEAs). Commercial desktop inkjet printers were used to deposit the active catalyst electrode layer directly from print cartridges onto Nafion ® polymer membranes in the hydrogen form. The layers were well-adhered and withstood simple tape peel, bending and abrasion tests and did so without any post-deposition hot press step. The elimination of this processing step suggests that inkjet-based fabrication or similar processing technologies may provide a route to less expensive large-scale fabrication of PEMFCs. When tested in our experimental apparatus, open circuit voltages up to 0.87 V and power densities of up to 155 mW cm −2 were obtained with a catalyst loading of 0.20 mg Pt cm −2 . A commercially available membrane under identical, albeit not optimized test conditions, showed about 7% greater power density. The objective of this work was to demonstrate some of the processing advantages of drop-on-demand technology for fabrication of MEAs. It remains to be determined if inkjet fabrication offers performance advantages or leads to more efficient utilization of expensive catalyst materials.
Medicalizing the drug war.

Recent findings in the field of psychopharmacology pertain to the abuse of drugs and alcohol among criminal offenders and have implications for new management techniques. Drugs of abuse exert their effects on areas of the brain responsible for pleasure, providing a powerful reinforcement for drug usage. Furthermore, there is a prevalence of psychological, psychiatric and social dysfunctions that antedate drug use which are identifiable at an early age. It is suggested that drugs of abuse differentially influence users via these biological, psychological and social mechanisms, reinforcing the development of serious and chronic abuse in a vulnerable subgroup. Studies of drug abuse specially indicate that within this subgroup, antisocial behavior precedes and exacerbates drug abuse, and multiple risk factors contribute to the concomitant development of criminality and drug abuse. Early detection and comprehensive treatment of underlying disorders that may both precipitate and result from drug abuse promise to improve possibilities for prevention and reducing relapse rates. Furthermore, the inclusion of pharmacologic treatments may further enhance the success of conventional drug treatments. This article proposes that incorporating scientific data and medicalizing our approach to drug abuse is essential to win the war against drugs. Language: en
Selection of Research Mentors for K‐Funded Scholars

Mentoring is an important element in the training of new investigators, particularly for KL2, K12, K08, and K23 funded scholars who are often physicians or other clinicians with limited prior research experience. Matching K scholars with appropriate mentors who have the mentoring skills and available time is an ongoing challenge for most universities. The goal of this paper is to present a variety of strategies used to select mentors for K awardees. The information presented in this special communication is derived from the literature, a national survey of CTSA leaders, as well as K scholar and K mentor focus groups. Some of the mentor selection methods discussed in this paper include a) having the scholar find a mentor as part of the application process for the award, b) selecting mentors post award, c) expecting the chair of the department to identify a mentor(s), d) using a committee to match the scholar and a mentor based on a pool of approved mentors e) selecting additional mentors as the scholar’s research program develops. The paper concludes that mentor selection requires an ongoing programmatic approach with the active participation of K scholars, CTSA program leaders, center directors, research deans and chairs.
Historical land use and environmental determinants of nonnative plant distribution in coastal southern New England.

Abstract The factors that influence the invasion of natural habitats by nonnative plants remain poorly understood. We investigated abiotic, biotic, and human influences on the distribution and abundance of nonnative species in coastal upland habitats of southern New England and adjacent New York, US. We censused vegetation and sampled soils in 776, 20 × 20 m plots in natural areas and constructed a spatially referenced GIS database of the region that included land-use history, distance from roads, and surficial geology. Our results indicate that the modern distribution of nonnative plants is influenced by multiple, interdependent current and historical factors. Glaciolacustrine landforms had greater nonnative species richness and cover than beach-dune, moraine, and glacial outwash sand plain landforms. Extant open-canopied areas (i.e., grasslands, dunes, heather barrens, and old fields) harbored significantly greater nonnative species richness and cover than closed-canopy forests, heathlands, and shrublands. Additionally, soil calcium levels and native species richness were positively associated with nonnative species richness. Sites that were cultivated historically or experienced other soil disturbance had higher nonnative species richness than areas without soil disturbance. Overall, abiotic, biotic and historical land use affected levels of nonnative species richness whereas nonnative cover was largely associated with abiotic conditions, particularly soil characteristics. Because many rare coastal sandplain plants reach their greatest abundance on extant open-canopied habitats, efforts to restore native plants will involve tradeoffs between the benefits of expanded habitat for these species and increased risk of invasion by nonnative species.
Copper(I) 3-Methylsalicylate Mediates the Chan–Lam N-Arylation of Heterocycles

Abstract Copper(I) 3-methylsalicylate (CuMeSal) mediates N-arylation reactions between aryl boronic acids and aromatic heterocycles (Chan–Lam coupling) under moderate reaction conditions (K2CO3, methanol, 65 °C, in air, 3–5 h). Both electron-rich and electron-deficient aryl boronic acids and a diverse set of N-heterocycles were allowed to react and gave N-arylation products in reasonable yields, which demonstrate the utility of this catalyst.
Evolution of the coronal and transition-zone plasma in a compact flare - The event of 1973 August 9

X-ray and extreme ultraviolet observations of a compact flare were analyzed to determine the relative importance of radiation, thermal conduction, and 'evaporation' in the evolution of the temperature and density structure of the plasma. In the event studied (1973 August 9), the electron density was relatively high (5 x 10 to the eleventh to 1 x 10 to the twelfth) and radiation was evidently an important energy-loss and cooling mechanism. The light curves of ultraviolet lines formed at temperatures between 10 to the fifth to 10 to the seventh K indicate a time-varying emission measure gradient, and hence temperature gradient, during the flare. Radiative instability evidently played an important role in determining the steepness of these gradients during the rise and fall phases, and caused strong downward motions of material during the cooling phase. Toward the end of the event, the coronal electron density decreased and the temperature gradient relaxed toward that expected from a conduction-dominated plasma. For this flare, evaporative cooling did not appear to be a significant factor.
Tsunami earthquakes possibly widespread manifestations of frictional conditional stability

[1] Tsunami earthquakes, shallow events that produce larger tsunamis than expected given their surface wave magnitudes (Ms), typically have long durations and a source spectrum depleted in short period energy. Seven cases of underthrusting tsunami earthquakes provide information on the rupture processes, but little constraint on geographic distribution or frequency. We compare their rupture characteristics with smaller magnitude earthquakes on circum-Pacific interplate thrust faults. Comparable moment release time histories are found for large tsunami earthquakes and for many smaller shallow subduction zone earthquakes, with significantly longer durations and additional source complexity than for events deeper than 15 km. Thus, very shallow interplate earthquake ruptures are scale invariant, with variable frictional properties on the plate interface controlling the depth dependent rupture process. Widespread occurrence of small shallow interplate earthquakes with long durations suggests that many subduction faults have frictional properties that may enable large tsunami-generating earthquakes to occur; fortunately, large shallow ruptures are infrequent.
Thermal degradation of foamed polystyrene

The thermal degradation of foamed polystyrene patterns in the expendable pattern casting (EPC) process has been studied. Various physical transitions that may occur during the degradation of the polymer have been determined with scanning electron microscopy, differential scanning calorimetry and thermogravimetric analysis. The effects of polymer density and bead structure on the degradation characteristics have been investigated. The results indicate that, when exposed to elevated temperatures, the polymer beads collapse at about 110–120 °C. The collapsed beads melt at 160 °C, and start to vaporize at temperatures greater than about 275 °C. Complete volatilization occurs in the temperature range 460–500 °C. The heat of degradation of expanded polystyrene has been estimated to be at the order of 912 Jg−1.
An admission control scheme for repair server in a tree-based reliable multicast

Tree-Based multicast protocols improved scalability, reliability, and error recovery using an efficiently constructed logical tree at the transport layer. Our research, however, discovered that the existing tree construction schemes need some improvement in the admission control by the repair server. In accepting new clients the existing schemes only consider their capacity as the criterion. This has resulted in logical trees comprised of widely diverse node characteristics including loss probabilities. Consequently these schemes consume more error recovery time than they would if the admission criterion was improved. We propose a new tree construction scheme that only accepts closely related loss probability receiver nodes in a group. When our scheme is simulated in comparison with the best known existing scheme, it shows a great deal of improvement in the average error recovery time ranging from an individual packet to the whole multicast session.
Developing deeper understandings of nature of science: the impact of a philosophy of science course on preservice science teachers’ views and instructional planning

This study aimed to assess the influence of a philosophy of science (POS) course on science teachers’ views of nature of science (NOS), perceptions of teaching about NOS, and instructional planning related to NOS. Participants were 56 undergraduate and graduate preservice secondary science teachers enrolled in a two science‐methods course sequence, in which participants received explicit, reflective NOS instruction. Ten of these participants were also enrolled in a graduate survey POS course. The Views of Nature of Science Questionnaire — Form C coupled with individual interviews was used to assess participants’ NOS views at the beginning and conclusion of the study. Participants’ lesson plans and NOS‐specific reflection papers were analysed to assess the impact of the POS course on their instructional planning related to, and perceptions of teaching about, NOS. Results indicated that, compared with participants enrolled in the methods courses, the POS course participants developed deeper, more coherent u...
Single-cell genomics

Methods for genomic analysis at single-cell resolution enable new understanding of complex biological phenomena. Single-cell techniques, ranging from flow cytometry and microfluidics to PCR and sequencing, are used to understand the cellular composition of complex tissues, find new microbial species and perform genome-wide haplotyping.
Thyroxine Vs. Triiodothyronine in the Fowl

Abstract Following the discovery of a previously unrecognized iodinated compound in mammalian thyroid and plasma (Gross et al. 1950), Gross and Pitt-Rivers (1952) identified the compound as 3:5:3′- l -triiodothyronine. Many subsequent investigations have shown that l -triiodothyronine (T-3) is several times as potent as l -thyroxine (T-4), as judged by various criteria in mammals and by tadpole metamorphosis (Roche and Michel, 1955). In experiments in our laboratory involving radiochromatography, L. B. Hardy, Jr, identified both T-3 and T-4 as components of chicken plasma in 1957 (unpublished data); and in 1958, one of us (B. C. W.) found T-3 and T-4 in both plasma and thyroid extracts from chickens (unpublished data). Shellabarger and Pitt-Rivers (1958) have also isolated both T-3 and T-4 from chicken thyroids. That the relative potencies of T-3 and T-4 might not be the same in the fowl as in mammals was indicated by Shellabarger (1955), who reported that T-3 was no …
Deriving tree diameter distributions using Bayesian model averaging

Diameter distributions of loblolly pine trees (Pinus taeda L.) were derived using Bayesian methods. The Bayesian derived distributions were compared to traditional maximum likelihood techniques for estimating diameter distributions. The data for this study come from a planting density study established in 1983 at four locations in Virginia and North Carolina. Results of the Bayesian analysis show that different distributional forms had the highest posterior probability at different ages for the diameter distributions. Standard goodness-of-fit statistics for the maximum likelihood estimates did not consistently recommend a distribution for the empirical data. Further, there were cases where no distribution was chosen from the candidate distributions based on the goodness-of-fit statistics. The lack of a clear distribution that fits over the range of ages for the diameter data suggests that a Bayesian model averaging technique would be beneficial for deriving tree diameter distributions with probability proportional to the posterior distribution. A simulation study was conducted to compare the goodness-of-fit statistics from the averaged distributional model and other candidate distributions. Results indicated that the averaged distribution had superior goodness-of-fit values over the candidate models; the exception being when the candidate distribution was an exact fit to the data.
Modeling design object relationships in PEGASUS

A description is given of the preliminary data model design of a database system for CAD applications named Pegasus. The model is based on previously published work on extensible and object-oriented database systems. Novel ideas of the model that are presented include the use of relationship objects as a modeling construct to represent relationships of any degree, and replication and the reconciliation of two subtyping mechanisms. The first, called refinement, is based on the usual semantics of schema copying; the second, called extension, is based on the inheritance semantics between prototypes and their extensions. These modeling elements are used to show how parts and assemblies (with their versions, components, etc.) can be modeled in the world of mechanical assembly design. >
An exploratory study of selected female registered nurses: meaning and expression of nurturance

The words 'nurse' and 'nursing' originate in the word 'nurture' which dates back to the 14th century. 'Nurturance' appeared for the first time in the 1976 Supplement to the Oxford English Dictionary and in a United States dictionary in 1983. Etymologically and semantically bound to nursing, little is known about the term nurturance. An exploratory design using phenomenological analysis was applied to understand the female registered nurses' experience of nurturing patients throughout the life-span and to uncover behaviours commonly believed nurturant. Interviews with 14 RNs practising in diverse settings revealed 39 nurturant behaviours that were intuited into four themes describing the subjects' perceived structure of nurturance as: (1) enabling maximum potential; (2) providing physical and emotional protection; (3) engaging in a supportive interaction; and (4) conveying shared humanity. Data were formulated into an exhaustive description of the phenomenon nurturance. Additionally, the results support Greenberg-Edelstein's theoretical model of the positive reciprocity of nurturance between nurse and patient.
Exocrine Pancreatic Neoplasms in the Mummichog (Fundulus heteroclitus) from a Creosote-Contaminated Site

A high prevalence of exocrine pancreatic neoplasms occurred in mummichog, Fundulus heteroclitus, from a creosote-contaminated site in the Elizabeth River, Virginia. A total of 20 neoplasms were found in a group of about 1,300 fish obtained at this site over a 2-yr period. Of 240 fish collected during October 1991, 3.3% had pancreatic neoplasms. Adjusted total lesion prevalence for large adult fish (Size Class III: total length = 75–85 mm; Size Class IV: total length > 85 mm) was 6.7%. Pancreatic neoplasms were not observed in 234 fish collected at this site during May 1991, nor were they found in 420 fish obtained during fall 1991 from 1 uncontaminated and 6 moderately contaminated localities. Lesions involved both mesenteric and intrahepatic exocrine pancreas and ranged from well-differentiated acinar cell adenomas to poorly differentiated acinar cell carcinomas. One fish had an atypical acinar cell focus. All specimens with pancreatic neoplasms also had hepatocellular lesions. This epizootic of exocrine...
Analysis of adiabatic shear bands in heat‐conducting elastothermoviscoplastic materials by the meshless local Bubnov–Galerkin method

Transient finite coupled thermomechanical simple shearing deformations of a block made of an elastothermoviscoplastic material that exhibits strain and strain-rate hardening, and thermal softening are studied by using the meshless local Bubnov–Galerkin method. A local nonlinear weak formulation and a semidiscrete formulation of the problem are derived. The prescribed velocity at the top and the bottom surfaces of the block is enforced by using a set of Lagrange multipliers. A homogeneous solution of the problem is perturbed by superimposing on it a temperature bump at the center of the block, and the resulting nonlinear initial-boundary-value problem is solved numerically. We have developed an integration scheme to numerically integrate the set of coupled nonlinear ordinary differential equations. The inhomogeneous deformations of the block are found to concentrate in a narrow region of intense plastic deformation usually called a shear band. For a material exhibiting enhanced thermal softening, it is shown that as the shear stress within the region of localization collapses, an unloading elastic shear wave emanates outward from the edges of the shear band. In the absence of an analytical solution, the computed results have been compared with those obtained by the finite element and the modified smoothed particle hydrodynamics methods. Copyright © 2008 John Wiley & Sons, Ltd.
Recruitment strategies and yields for the pathobiology of prediabetes in a biracial cohort: A prospective natural history study of incident dysglycemia

The Pathobiology of Prediabetes in A Biracial Cohort study is a prospective evaluation of the transition from normal to impaired glucose regulation among African American and Caucasian adults with parental type 2 diabetes. This report describes recruitment strategies and relative yields for the 376 enrolled subjects. Recruitment occurred over 3.4 years, with clinical and metabolic assessments during 2.1-5.5 years of quarterly follow-up. The major recruitment sources were advertisements, community outreach, and clinical facilities. Advertisements included newspaper, television, radio, Internet, distributed brochures, utility bill inserts, and direct mailing. Community outreach included screening events during religious gatherings and health fairs, and referral by friends and families. The category of clinical facilities covered all subjects referred by health workers or recruited through area clinics and hospitals. 57.7% of participants were African American and 42.3% were Caucasian; the mean age (± SD) was 44.2 ± 10.6 years, and ~70% were female. Advertisements yielded 52.4% of all participants, compared to 34.8% from community outreach and 12.8% from clinical facilities (P for trend < 0.0001). More Caucasians than African Americans cited advertising as the source of study information, whereas more African Americans than Caucasians cited community outreach. The accrual from clinical facilities was similar in both groups. Advertisements and community outreach were robust recruitment sources for assembling a diverse longitudinal diabetes offspring cohort, but each had differential yields in African Americans and Caucasians. Thus, a multifaceted approach comprising passive and active components is needed to recruit a multiracial clinical research population.
Evaluating Utility of Cold-Injury Syndromic Surveillance Data in New York City

Cold weather exposure-related injuries are preventable causes of mortality and morbidity. We conducted a retrospective analysis to compare hypothermia and cold-injury case characteristics, and temporal and meteorological correlates, between 2008-2010 cold season syndromic surveillance and hospital discharge data. Poisson regression models were fit to estimate the relation of daily case counts with temperature, snow depth, and other weather conditions. There were no meaningful differences in relationships with weather variables across data sources. Daily mean minimum temperature and snow depth are potentially useful in determining timing of analyses. Syndromic surveillance could provide useful information to guide cold-related injury prevention.
Can spermatozoa with abnormal heads gain access to the ovum in artificially inseminated super- and single-ovulating cattle?

Abstract The collective efficiency of barriers in the female tract against spermatozoa with abnormal heads was studied. In Experiment 1, Day 6 ova/embryos were recovered nonsurgically from superovulated (n=24) and single-ovulating (n=44) cows following artificial insemination with semen of bulls selected for normal spermatozoal motility (≥50%) and high content (>30%) of spermatozoa with misshapen heads, random nuclear vacuoles or the diadem defect. To assess characteristics of spermatozoa capable of traversing barriers in the female tract, accessory spermatozoa were classified morphologically (× 1250) and compared with those of the inseminate. Superovulated cows proved inadequate for assessment of accessory spermatozoa due to evidence of poor sperm retention in the zona pellucida; thus, only single-ovulating cows were used. Accessory spermatozoa (n=479) from 31 ova/embryos recovered from 44 cows were more normal in head shape than those in the inseminate (76 vs 62%; P
The Current Status and Future Prospects of the Salivary Proteome

Saliva performs many biological functions that are instrumental in maintaining oral health. Digestive enzymes, such as alpha-amylase and antimicrobial proteins, such as lysozyme and cystatin, are present at high concentrations in human saliva. It is a readily available atraumatic body fluid, useful in the diagnosis of disease, aging and oral health. Large scale analysis of salivary proteins is important for biomarker discovery. However, the abundance of some salivary proteins and contamination with proteins from food and mouth bacteria obscures identification of medium and low copy salivary proteins. In this review, we summarize current knowledge of the salivary proteome using mass spectrometry based technologies.
Review of Donald C. Austin's Book: Creative Evolution Revisited: A New Theological Theory of Evolution

Suzan Mazur describes the evolution industry in crisis, given an apparent emptiness in the neo-Darwinian account. Mazur interviewed many world-wide scholars, and not just those that attended the 2008 meeting in Altenberg, Austria. Stewart Newman, Antonio Lima-de-Faria and Lynn Margulis provide among of the most interesting and credible accounts of an evolution that is not stuck in a dogmatic and hopeless neo-Darwinism. This is not to say that most scientists don`t still over prescribe Darwin`s simplistic theory, and some of these folks are interviewed in Mazur`s book. You can find this book at Amazon: Creative Evolution Revisited: A New Theological Theory of Evolution .
β-Amyloid1–42 Gene Transfer Model Exhibits Intraneuronal Amyloid, Gliosis, Tau Phosphorylation, and Neuronal Loss

Alzheimer disease is characterized by extracellular β-amyloid (Aβ) plaques and intracellular inclusions containing neurofibrillary tangles of phospho-Tau and intraneuronal Aβ associated with neuronal cell death. We generated a novel gene transfer animal model using lentiviral Aβ1–42 that resulted in intracellular but not extracellular Aβ accumulations in the targeted rat primary motor cortex. Expression of intracellular Aβ1–42 led to pathological changes seen in human Alzheimer disease brains, including cell death, inflammatory signs, activation of two Tau kinases, and Tau hyperphosphorylation. Promoting clearance of lentiviral Aβ1–42 reversed these effects, demonstrating that intraneuronal Aβ1–42 is a toxic peptide that lies upstream of Tau modification. These studies reveal the role of intracellular Aβ1–42 in a novel gene transfer animal model, which is a useful tool to study intraneuronal Aβ1–42-induced pathology in the absence of extracellular plaques. Targeted delivery of Aβ will allow speedy delineation of pathological mechanisms associated with specific neurodegenerative lesions.
Fixing weakly annotated web data using relational models

In this paper, we present a fast and scalable Bayesian model for improving weakly annotated data - which is typically generated by a (semi) automated information extraction (IE) system from Web documents. Weakly annotated data suffers from two major problems: they (i) might contain incorrect ontological role assignments, and (ii) might have many missing attributes. Our experimental evaluations with the TAP and RoadRunner data sets, and a collection of 20,000 home pages from university, shopping and sports Web sites, indicate that the model described here can improve the accuracy of role assignments from 40% to 85% for template driven sites, from 68% to 87% for non-template driven sites. The Bayesian model is also shown to be useful for improving the performance of IE systems by informing them with additional domain information.