cssi/SciSciGPT-SciSciNet huggingface dataset:
Strain measurement of ultrathin epitaxial films using electron diffraction techniques

Many diffraction and imaging techniques have been developed and used to measure the strains in epitaxial films with different degrees of accuracy. In this tutorial, we will focus on measurements of strains in epitaxial films using electron diffraction techniques. These include reflection high-energy electron diffraction (RHEED), azimuthal reflection high-energy electron diffraction, low-energy electron diffraction (LEED), and high-resolution low-energy electron diffraction techniques. These diffraction techniques are surface sensitive and are suitable for in situ measurements of strains in ultrathin epitaxial films quantitatively. In particular, RHEED and LEED are simple to operate and readily available in many laboratories. We discuss the instrument limit of strain measurement in each technique. A nominal definition of the resolving power of an instrument to resolve a strain state is given as the percentage of intrinsic instrumental broadening in the reciprocal unit with respect to the first reciprocal Brillouin zone (2π/lattice constant) of a sample. It is shown that the resolving power of these diffraction techniques ranges from 2% to 0.2%. Experimental strategies without modifying the instrument and to achieve a strain detection capability beyond the definition of the nominal resolving power of these techniques are presented.
Synergistic Effect of Elevated Device Temperature and Excess Charge Carriers on the Rapid Light‐Induced Degradation of Perovskite Solar Cells

With power conversion efficiencies now reaching 24.2%, the major factor limiting efficient electricity generation using perovskite solar cells (PSCs) is their long-term stability. In particular, PSCs have demonstrated rapid degradation under illumination, the driving mechanism of which is yet to be understood. It is shown that elevated device temperature coupled with excess charge carriers due to constant illumination is the dominant force in the rapid degradation of encapsulated perovskite solar cells under illumination. Cooling the device to 20 °C and operating at the maximum power point improves the stability of CH3 NH3 PbI3 solar cells over 100× compared to operation under open circuit conditions at 60 °C. Light-induced strain originating from photothermal-induced expansion is also observed in CH3 NH3 PbI3 , which excludes other light-induced-strain mechanisms. However, strain and electric field do not appear to play any role in the initial rapid degradation of CH3 NH3 PbI3 solar cells under illumination. It is revealed that the formation of additional recombination centers in PSCs facilitated by elevated temperature and excess charge carriers ultimately results in rapid light-induced degradation. Guidance on the best methods for measuring the stability of PSCs is also given.
Inferring the anthropogenic NO x emission trend over the United States during 2003–2017 from satellite observations: was there a flattening of the emission trend after the Great Recession?

Abstract. We illustrate the nonlinear relationships among anthropogenic NOx emissions, NO2 tropospheric vertical column densities (TVCDs), and NO2 surface concentrations using model simulations for July 2011 over the contiguous United States (CONUS). The variations in NO2 surface concentrations and TVCDs are generally consistent and reflect anthropogenic NOx emission variations for high anthropogenic NOx emission regions well. For low anthropogenic NOx emission regions, however, nonlinearity in the anthropogenic-emission–TVCD relationship due to emissions from lightning and soils, chemistry, and physical processes makes it difficult to use satellite observations to infer anthropogenic NOx emission changes. The analysis is extended to 2003–2017. Similar variations in NO2 surface measurements and coincident satellite NO2 TVCDs over urban regions are in sharp contrast to the large variation differences between surface and satellite observations over rural regions. We find a continuous decrease in anthropogenic NOx emissions after 2011 by examining surface and satellite measurements in CONUS urban regions, but the decreasing rate is lower by 9 %–46 % than the pre-2011 period.
Toward a BEA-BLS integrated industry-level production account for 1947–2016

Abstract This chapter presents new collaborative research work by the BEA and BLS toward an integrated industry-level production account that covers 1947 to 2016, the entire time span of the GDP by Industry accounts. The prototype estimates that we have constructed reveal that for the past decade and a half, relatively slow input growth (in capital and labor services) has curtailed US economic growth, even relative to the long slump between 1973 and 1995. The low contribution of capital input was concentrated in the Finance, insurance, real estate, rental and leasing and Manufacturing sectors, while the low contribution from labor was spread more equally across sectors.
Using reverse osmosis membranes to control ion transport during water electrolysis

The decreasing cost of electricity produced using solar and wind and the need to avoid CO2 emissions from fossil fuels has heightened interest in hydrogen gas production by water electrolysis. Offshore and coastal hydrogen gas production using seawater and renewable electricity is of particular interest, but it is currently economically infeasible due to the high costs of ion exchange membranes and the need to desalinate seawater in existing electrolyzer designs. A new approach is described here that uses relatively inexpensive commercially available membranes developed for reverse osmosis (RO) to selectively transport favorable ions. In an applied electric field, RO membranes have a substantial capacity for proton and hydroxide transport through the active layer while excluding salt anions and cations. A perchlorate salt was used to provide an inert and contained anolyte, with charge balanced by proton and hydroxide ion flow across the RO membrane. Synthetic seawater (NaCl) was used as the catholyte, where it provided continuous hydrogen gas evolution. The RO membrane resistance was 21.7 ± 3.5 Ω cm2 in 1 M NaCl and the voltages needed to split water in a model electrolysis cell at current densities of 10–40 mA cm−2 were comparable to those found when using two commonly used, more expensive ion exchange membranes.
Development of the Nude Rabbit Model.

Summary Loss-of-function mutations in the forkhead box N1 (FOXN1) gene lead to nude severe combined immunodeficiency, a rare inherited syndrome characterized by athymia, severe T cell immunodeficiency, congenital alopecia, and nail dystrophy. We recently produced FOXN1 mutant nude rabbits (NuRabbits) by using CRISPR-Cas9. Here we report the establishment and maintenance of the NuRabbit colony. NuRabbits, like nude mice, are hairless, lack thymic development, and are immunodeficient. To demonstrate the functional applications of NuRabbits in biomedical research, we show that they can successfully serve as the recipient animals in xenotransplantation experiments using human induced pluripotent stem cells or tissue-engineered blood vessels. Our work presents the NuRabbit as a new member of the immunodeficient animal model family. The relatively large size and long lifespan of NuRabbits offer unique applications in regenerative medicine, cancer research, and the study of a variety of other human conditions, including immunodeficiency.
Coercing Clients: Can Lawyer Gatekeeper Rules Work?

Recent federal regulations and amendments to the Model Rules of Professional Conduct—most of which have responded to lawyer involvement in corporate scandals—rest on the assumption that lawyers have a role to play in forcing clients to act legally, morally, or appropriately. Lawyers are distinctive, perhaps even unique among professionals, in that they are sometimes legally authorized to force clients into obeying the lawyers' advice. This Article reviews the rules that empower lawyers in this way, with a focus on the corporate context. For the most part, the recent regulatory changes take a static view of the lawyer-client relationship. They assume that if lawyers are authorized or required to counteract proposed client misconduct, lawyers will do so and less client misconduct will result. This Article demonstrates that the reality is far more complex. Lawyers and clients have incentives to implement coercive rules in ways that serve reasons wholly unrelated to the rules' purposes. Code drafters and those evaluating lawyers' coercive authority, therefore, must confront the fact that attorney-client relationships are dynamic—that is, that a change in the power of one party in the relationship has ripple effects. This practical reality influences both the positions of lawyers in deciding whether to favor or oppose particular regulation and the likely effectiveness of coercive rules.
A One Year Forecasting Project For Publicly Traded Companies

This project is intended to teach students to apply the material covered in their first graduate accounting course. This is accomplished by applying the material to an actual company selected by each team. The project is described as follows: The project includes a computerized spreadsheet preparation of a master budget forecast for an actual publicly traded company for one year into the future. . The dates depend upon when the annual reports are prepared for your company. The forecast begins the day following the last available published annual report. The forecast does not comprise any actual numbers regardless of when the actual annual or quarterly statements are prepared for the company selected. The actual balance sheet, income statement and statement of cash flow from the preceding year are included with the forecasted balance sheet, income statement and statement of cash flow. The company must have a physical inventory, and accounts receivable from sales. The company may not be one in which any team member(s) are employed. The forecast will include the following items:
Fractal-like energy transport and fusion in a naphthalene-doped polymeric glass

Abstract Singlet energy transport in naphthalene-doped poly (methylmethacrylate) (PMMA) samples has been found, by doping with anthracene, to follow Stern-Volmer kinetics with a transfer rate constant ca. 2x10 9 . Delayed fluorescence is easily observed; triplet energy transport seems to have fractal-like properties.
Hydrothermal systems associated with martian impact craters

Abstract With widespread evidence of both heat sources and water (either liquid or solid), hydrothermal systems are likely to have existed on Mars. We model hydrothermal systems in two sizes of fresh impact craters, one simple and one complex, and find that a hydrothermal system forms on the crater floor. In the larger complex craters with a substantial melt sheet, a lake can form, even under current martian atmospheric conditions. By comparing these hydrothermal systems to those that exist and have been studied extensively on the Earth, we make predictions as to the types of minerals that could be precipitated and the potential habitability of such systems by primitive organisms.
Epstein-Barr (EB) virus antibodies in rheumatoid arthritis.

It is now known that the sera of patients with rheumatoid arthritis (RA) contain antibodies directed to a nuclear antigen, RANA (RA-associated nuclear antigen), present in Epstein-Barr virus (EBV) infected cells. These antibodies are present in a majority of RA patients but are found in low frequencies in other rheumatic diseases. In addition to anti-RANA, other EBV antibodies such as antiviral capsid antigen (VCA) are present in elevated titers and anti-early antigen (EA) are present in elevated titers and increased frequency. Investigations of RA lymphocytes after in vitro EBV infection have revealed aberrant immune regulation of EBV infection and markedly increased rheumatoid factor production by RA lymphocytes. Although there is increasing evidence associating EBV with RA, the precise role of this virus in the pathogenesis of RA is not known at this time but further studies designed to explore virus-host immune interactions would appear to be most important.
Sequential Sampling Plans for Use in Timing Insecticide Applications for Control of European Corn Borer (Lepidoptera: Pyralidae) in Potato

Sequential sampling plans were developed for use in recommending control of European corn borer, Ostrinia nubilalis (Hubner), in potato, Solanum tuberosum L., fields based on the distribution of damaged stems. Likelihood ratio tests indicated that the beta-binomial distribution (aggregated) provided a better fit than the binomial (random) when the mean percentage of damaged stems in a field was ≥6%, but not when damage was <6%. Similarly, variance-ratio ( D ) and C ( a ) tests indicated that damage was aggregated generally at damage levels ≥6%. Because the slope ( b ) ± SEM of the binary form of the Taylor power law (1.15 ± 0.05) (total of 41 fields) revealed moderate overdispersion, and a weak linear relationship existed between the index of aggregation ( θ ) and p , sequential sampling plans were evaluated under various degrees of aggregation. The precision and practicality of the sequential sampling plans were evaluated through calculation of operational characteristic and average sample number functions for both simulated binomial and beta-binomial distributions. Precision of the sequential sampling plans decreased as the aggregation of O. nubilalis damage increased, especially when the proportion of damaged stems was near threshold. However, needed to make the decision.
Tool‐using chimpanzees

Review of Folk Physics for Apes. The Chimpanzee’s Theory of How the World Works by Daniel J. Povinelli, in collaboration with James E. Reaux, Laura A. Theall, and Steve Giambrone. Oxford, Oxford University Press, 2000, xiii + 391 pp, 98 fig., 35 tab., $85.00.
All-optical routing schemes for networks using wavelength recognizing switches

We have recently described a wavelength-recognizing switch (WRS) which we showed to be capable of truly all-optical routing. Although other authors had previously reported "all-optical" networks [1, 2, 3], the term has generally referred to all—optical data paths only. In such implementations only the data remains in optical format as it propagates along the network paths. Optical-to-electronic conversions are still allowed for what is termed "control signals," namely address bits and additional signaling entities, which are assumed to have lower speed than the data. In contrast, the WRS we presented has the capability to route data by interpreting the control signals in the optical domain, thus avoiding the overhead and the latency ofthe optic-to-electronic conversion. In a series of previous publications [4, 5] we demonstrated the experimental viability of the WRS and measured some of the relevant system parameters of the device. More recently, we published details on how the device could be used to build multistage all-optical self-routing networks. We also developed a simulation model and estimated the maximum number of stages that can be cascaded in such networks. The work presented in this paper carries the simulation results one step further, and investigates some of the possible topologies that can be used for WRS networks, as well as the system implications of these topologies. To facilitate a better understanding of the concepts presented, we briefly review the device functionality and the main experimental results that affect the system performance. We then show how to implement some of the building blocks we use in the self-routing topologies, and explain the equalization mechanism necessary for using WRS in multistage networks. We then compare the practical advantages of the topologies of interest and decide which topology is the most probable implementation. Finally we present details on a new generation of WRS, which is waveguide based, thus more easily fabricated and integrated with optical fiber systems
Temperature and direction dependence of internal strain and texture evolution during deformation of uranium

Abstract Depleted uranium is of current programmatic interest at Los Alamos National Lab due to its high density and nuclear applications. At room temperature, depleted uranium displays an orthorhombic crystal structure with highly anisotropic mechanical and thermal properties. For instance, the coefficient of thermal expansion is roughly 20 × 10−6 °C−1 in the a and c directions, but near zero or slightly negative in the b direction. The innate anisotropy combined with thermo-mechanical processing during manufacture results in spatially varying residual stresses and crystallographic texture, which can cause distortion, and failure in completed parts, effectively wasting resources. This paper focuses on the development of residual stresses and textures during deformation at room and elevated temperatures with an eye on the future development of computational polycrystalline plasticity models based on the known micro-mechanical deformation mechanisms of the material.
Swelling of Hot-Pressed A12O3

Fully dense aluminas, prepared by hot-pressing, were found to swell during annealing at 1600°C in air, but not during annealing in a reducing atmosphere (po2= 10-7 Pa). The reaction followed the relation p - po = -K log t, where po and p are the initial and final densities, respectively, t is the time, and AT is a constant. The rate of swelling was enhanced by MgO solute. The reduction in density resulted from the nucleation and growth of grain-boundary pores. Pore formation was attributed to the reaction of carbon and sulfur impurities at the boundaries with oxygen, which had diffused down the grain boundaries from the ambient, to form CO/CO2 and SO2 gas at high pressures. Preliminary results indicate that this reaction can be avoided by preannealing powders in flowing oxygen prior to hot-pressing. The consequences of internal gas-forming reactions to other processes such as high-temperature creep and sintering are also discussed.
Opportunities and roadblocks in utilizing forages and small grains for liquid fuels

This review focuses on the potential advantages and disadvantages of forages such as switchgrass (Panicum virgatum), and two small grains: sorghum (Sorghumbicolor), and wheat (Triticum aesitvum), as feedstocks for biofuels. It highlights the synergy provided by applying what is known from forage digestibility and wheat and sorghum starch properties studies to the biofuels sector. Opportunities therefore, exist to improve biofuel qualities in these crops via genetics and agronomics. In contrast to cereal crops, switchgrass still retains tremendous exploitable genetic diversity, and can be specifically improved to fit a particular agronomic, management, and conversion platform. Combined with emerging studies on switchgrass genomics, conversion properties and management, the future for genetic modification of this species through conventional and molecular breeding strategies appear to be bright. The presence of brown-midrib mutations in sorghum that alter cell wall composition by reducing lignin and other attributes indicate that sorghum could serve as an important model species for C4-grasses. Utilization of the brown-midrib traits could lead to the development of forage and sweet sorghums as novel biomass crops. Additionally, wheat crop residue, and wheat and sorghum with improved starch content and composition represent alternate biofuel sources. However, the use of wheat starch as a biofuel is unlikely but its value as a model to study starch properties on biofuel yields holds significant promise.
In vitro study of magnetic nanoparticles as the implant for implant assisted magnetic drug targeting

Abstract Magnetic nanoparticle (MNP) seeds were studied in vitro for use as an implant in implant assisted-magnetic drug targeting (IA-MDT). The magnetite seeds were captured in a porous polymer, mimicking capillary tissue, with an external magnetic field (70 mT) and then used subsequently to capture magnetic drug carrier particles (MDCPs) (0.87 μm diameter) with the same magnetic field. The effects of the MNP seed diameter (10, 50 and 100 nm), MNP seed concentration (0.25–2.0 mg/mL), and fluid velocity (0.03–0.15 cm/s) on the capture efficiency (CE) of both the MNP seeds and the MDCPs were studied. The CE of the 10 nm MNP seeds was never more than 30%, while those of the 50 and 100 nm MNP seeds was always greater than 80% and in many cases exceeded 90%. Only the MNP seed concentration affected its CE. The 10 nm MNP seeds did not increase the MDCP CE over that obtained in the absence of the MNP seeds, while the 50 and 100 nm MNP seeds increased significantly, typically by more than a factor of two. The 50 and 100 nm MNP seeds also exhibited similar abilities to capture the MDCPs, with the MDCP CE always increasing with decreasing fluid velocity and generally increasing with increasing MNP seed concentration. The MNP seed size, magnetic properties, and capacity to self-agglomerate and form clusters were key properties that make them a viable implant in IA-MDT.
Optoelectronic strain measurement for flywheels

Conceptual improvements to a non-contact optical strain measurement technique for high-speed flywheels are presented. The improvements include a novel reflective pattern that allows for greater displacement sensitivity, the ability to measure rigid body vibrations and separate the associated vibration-induced displacement from the strain-induced displacement, and the ability to compensate for potential sensor drift during flywheel operation. The effects of rigid body rotor vibrations and sensor drift have been modeled and techniques to compensate for the errors associated with such effects are presented. Experimental results validate the ability of the technique to separate such vibrations from axisymmetric flexible body displacements, and to compensate for errors due to in-plane and out-of-plane pattern misalignment and sensor drift. Displacement measurements made on an aluminum rotor operating at a maximum speed of 16 krpm (255 m/s at the point of measurement) were made with ±1 μm accuracy. At this speed, hoop strains were found to be within 40–125 μe of theoretical predictions, provided a proper accounting is made for thermal strains. Relative to the theoretical hoop strains, the measured hoop strains differed by 5.0 to 6.4% at 16 krpm.
Use of the internet by Italian pediatricians: habits, impact on clinical practice and expectations

Background Medical professionals go online for literature searches and communication with families. We administered a questionnaire to members of the Italian Society of Pediatrics to assess determinants of their use of the Internet, of social platforms and of personal health records during clinical practice.
Life cycle of Phacellophora camtschatica (Cnidaria: Scyphozoa)

. Gelatinous zooplankton play important roles in marine ecosystems and at times can have significant impacts on human activities. Many scyphozoans have enigmatic life cycles and the specific habitat for benthic life history stages is unknown. This is especially true for many of the large surface-cruising scyphomedusae of the northeast Pacific Ocean. Phacellophora camtschatica belongs to the family Ulmaridae and is known to have scyphistomae in the life history. However, the life cycle of P. camtschatica has not been formally described. Here the life cycle of members of P. camtschatica is described based on laboratory observations and compared with early life history stages in the scyphomedusa Aurelia labiata.
The effect of salt on the binding of the eucaryotic DNA nicking-closing enzyme to DNA and chromatin

Abstract The optimum monovalent cation concentration (Na+ or K+) for the relaxation of superhelical DNA by the rat liver nicking-closing enzyme under conditions of DNA excess was found to be 150–200 mM. The detection of a nicked DNA species after stopping a reaction with alkali depends on having a high molar ratio of enzyme to DNA and is maximal between 50 and 100 mM monovalen cation. Varying the salt concentration from 15 to 200 mM appears to have no effect on the catalysis of the nicking-closing reaction by the enzyme. Instead different salt optima in these two assays can be explained by the observation that the nicking-closing enzyme acts by a processive mechanism below 100 mM salt and becomes nonprocessive above 150 mM. The salt elution of the nicking-closing enzyme from resting cell chromatin appears to be similar to that which one would expect for the elution of the enzyme from naked DNA. However, greater than 70% of the chromatin associated enzyme activity remained bound to chromatin from growing cells at 300 mM salt, a concentration at which there is no significant binding to naked DNA in vitro.
Characterization of the passive inorganic interphase and polypyrrole coatings formed on steel by the aqueous electrochemical process

Polypyrrole coatings have been successfully formed on steel from aqueous oxalic acid-pyrrole solutions by electrochemical polymerization. Formation of the coatings was found to be dependent on the pH of the reaction solution and the applied current. In acidic medium, the formation of polypyrrole was characterized by an induction (passivation) period before electropolymerization of pyrrole. At the end of the induction period, a crystalline passive interphase was formed. The morphology and composition of the electrodeposited passive interphase and the resultant polypyrrole coatings were investigated by scanning electron microscopy, reflection-absorption infrared spectroscopy, and X-ray photoelectron spectroscopy. Our results reveal that the chemical composition of the passive interphase was similar to that of iron(II) oxalate dihydrate, FeC 2 O 4 . 2H 2 O, crystals. Size and orientation of the crystalline passive interphase varied with electrochemical process variables.
Association between Free Testosterone Levels and Anal Human Papillomavirus Types 16/18 Infections in a Cohort of Men Who Have Sex with Men

Background Human papillomavirus (HPV) types 16 and 18 cause invasive cervical cancer and most invasive anal cancers (IACs). Overall, IAC rates are highest among men who have sex with men (MSM), especially MSM with HIV infection. Testosterone is prescribed for men showing hypogonadism and HIV-related wasting. While there are direct and indirect physiological effects of testosterone in males, its role in anal HPV16/18 infections in men is unknown.
Controls on open water evaporation

Abstract. The paper presents the initial results of a field study of boundary layer behaviour and open water evaporation carried out on two small- to medium-sized lakes in Western and Northern Canada. Meteorological and boundary layer measurements were made over the water surfaces and over the upwind land surface, allowing for an examination of the effect of lake-land contrasts of temperature on the wind speed over the open water and on the evaporation rates. Lake evaporation was measured directly using eddy covariance equipment. The study showed that, for time periods shorter than daily, the open water evaporation bears no relationship to the net radiation. The wind speed is the most significant factor governing the evaporation rates, followed by the land-water temperature contrast and the land-water vapour pressure contrast. The effect of the stability on the wind field is demonstrated; stability over the water and adjacent land surfaces are, for the most part, out of phase. The derived relationships will be used to develop a model for estimating the hourly evaporation rates from open water. Examination of the seasonal trends shows that the open water period can be separated into two distinct evaporative regimes: the warming period in the Spring, when the land temperature is greater than the water temperature, the turbulent fluxes over water are suppressed; and the cooling period, when the water temperature is greater than the air temperature, and the turbulent fluxes over water are enhanced.
Removal of the polar lobe leads to the formation of functionally deficient photocytes in the annelidChaetopterus variopedatus

The light emitting photocytes ofChaetopterus variopedatus larvae are bilaterally situated within the ectoderm of the post-trochal region. Their histological appearance is similar to that of the adult photocytes. The larval photocytes contain a large quantity of membranous secretory vesicles (photosomes), which probably contain the photoluminescent protein. The two-cellChaetopterus embryo contains a small AB and a large CD blastomere. Previous studies have shown that only the "larvae" resulting from isolated CD blastomeres are able to luminesce. Consistent with these findings, morphologically distinct photocytes are only found in the CD larvae. The removal of the small polar lobe that forms during first cleavage leads to the production of a "larva" that is unable to produce light. All delobed larvae contain morphologically distinct photocytes, which are identical to those in normal larvae except they appear to contain only a small quantity of photosomes. Experimental equalization of first cleavage leads to the production of a double embryo. While photocytes are found in both of the duplicated post-trochal regions, usually only one of these is capable of emitting luminescence. Apparently, the highly localized vagetal material (determinants) responsible for functional light emission is distributed to both halves in only a few cases when first cleavage is experimentally "equalized". These results indicate that the determinative action of the polar lobe is not required for the formation of the photocytes themselves, but rather for their ability to function as emitters of light. The determinants in the polar lobe ofChaetopterus may control some aspect of the photoluminescence reaction itself, such as the production of the photoprotein.
Three-dimensional structure of a type VI turn in a linear peptide in water solution Evidence for stacking of aromatic rings as a major stabilizing factor

Structures have been calculated for the folded conformation found at high population in the cis isomeric form of the peptide NH3(+)-Ser-Tyr-Pro-Phe-Asp-Val-COO- (SYPFDV) in aqueous solution, using distance geometry and restrained molecular dynamics. A number of NMR parameters, including NOE distance restraints and phi and chi 1 dihedral angle restraints derived from coupling constants were used in the calculation. The restraints were carefully selected to exclude those that might have a significant contribution from the unfolded states of the peptide, so that the calculated structure represents only the folded form (present at about 70% population) and contains no information on the other members of the conformational ensemble. The calculations give a tight family of structures in the region Tyr2 to Phe4, all containing a type VI turn with an unusual disposition of the aromatic rings of Tyr and Phe, which stack against the proline ring. Both backbone and side-chain conformations are well defined in this region. At the ends of the molecule the polypeptide chain is disordered. The structures are consistent with all of the available NMR information, including upfield chemical shifts observed for the proline ring protons in the cis isomer, and with the independently determined proline ring pucker. There is no evidence for cross-turn hydrogen bonding. According to the calculated structures, the major source of stabilization of the turn conformation appears to be the stacking of the aromatic and proline rings.
Common sense computing (episode 4): debugging

We report on responses to a series of four questions designed to identify pre-existing abilities related to debugging and troubleshooting experiences of novice students before they begin programming instruction. The focus of these questions include general troubleshooting, bug location, exploring unfamiliar environments, and describing students' real life troubleshooting experiences. We find that the common sense experience of students related to debugging is often at odds with the needs for debugging programs. Student troubleshooting experiences recognize real world non-determinism and rarely require undoing an attempted fix. Based on student answers, we shed light on some specific frustrations of instructors and make a set of recommendations for teaching, including addressing the difference between finding an error and fixing it, modeling the formation of multiple hypotheses, and encouraging students to apply domain knowledge.
A comparative study of three methods for analysing longitudinal pulmonary function data

We compare three methods of longitudinal analysis of pulmonary function data. Our data set is taken from a study of exposure to toluene diisocyanate (TDI) vapours in a new manufacturing plant. The first two methods are a two-stage weighted regression method and maximum likelihood estimation via the EM algorithm, and these give very similar results. The third method, regression with an autoregressive error structure, was not successfully implemented, and in our view needs better documentation.
Detector cooling options for temperatures as low as 10 mK

Upcoming far-IR space missions are faced with a very challenging requirement: to make detectors with sufficient sensitivity to be limited by the photon noise present in the darkness of space. At long wavelengths (>100μm), where the Zodiacal light is insignificant and the sky brightness corresponds to only ~100 aW, detectors must have noise equivalent powers of <10-19 W/√Hz. For fundamental reasons, this can only be achieved with detectors operating at about 20 mK, giving rise to the need for refrigerators capable of operating as low as 10 mK. Only adiabatic demagnetization refrigerators (ADR) have demonstrated both zero-g operation and the capacity for cooling into this regime. Over the last few years we have developed a multi-stage ADR that can produce continuous cooling at temperatures of 35 mK or lower, and have recently begun developing additional stages that will push the operating range below 10 mK. Our prototype device uses a 4.2 K heat sink, but it can easily work with pulse-tube or Gifford-McMahon cryocoolers. We describe the design, operation and capabilities of the ADR, as well as the cryogen-free dewar that will be used for performance tests.
Inhibition of Respiration at Site I by Asimicin, an Insecticidal Acetogenin of the Pawpaw, Asimina triloba (Annonaceae)

Abstract The insecticidal mode of action of the acetogenin asimicin and a standardized acetogenin extract, FO20, isolated from Asimina triloba Dunal was investigated. Dietary FO20 reduced the rate of oxygen consumption by fourth instar Ostrinia nubilalis as measured with a constant volume manometer. Further examination of the respiratory effect of both FO20 and asimicin was carried out on mitochondria isolated from the midguts of fifth instar O. nubilalis and in which O 2 was measured polarographically. The results of these studies indicate a significant reduction in state 3 respiration using malate and pyruvate as substrate, caused by asimicin (concentration for 50% inhibition = 0.55 nmol/mg protein) or FO20 (I 50 = 1.69 μg/mg protein). No reductions of ADP:O or respiratory control ratios were observed in partially inhibited mitochondria. Oxygen uptake was restored and state 3 respiration was not inhibited when succinate was the substrate. These results are evidence of a site of inhibition between NADH and ubiquinone (site 1) within the electron transport chain.
The deformation behavior of isoaxial bicrystals of Fe-3%Si☆

Abstract The slip occurring in bicrystals of a high purity Fe-3 %Si alloy subjected to small plastic strains by deformation in compression was investigated using etch pitting techniques. Four isoaxial types of bicrystals, each containing a planar boundary parallel with the compression axis, were studied. Each of the component crystals was oriented for 〈111〉 {011} type single slip. The deformation behavior is examined in terms of the compatibility requirements imposed at the grain boundary plane and the effect of elastic anisotropy on the mutual interaction between crystals. Elastic incompatibility at the grain boundary plane is found to give rise to local stresses which result in the operation of secondary slip systems not normally expected to be operative in the individual single crystal components.
The set up of primary calibration system for shock acceleration in NML

Abstract This paper mainly describes Taiwan’s metrology National Measurement Laboratory (NML) to set up and evaluate a shock accelerometer calibration system which follows the ISO 16063-13:2001 standard. The environmental shock testing of electro-acoustics or electronic spare parts, the product packing falling impact, the automobile collision and the helmet impact test and so on are more and more important for quality and safety. In consideration of that, NML has started to establish the primary shock calibration system which calibrates the accelerometer sensitivity and trace to the metric unit since 2009. The shock machine structure comprises three parts; they are the electromagnetic high-speed hammer, airborne hammer and airborne anvil. The shock machine impact source of primary shock calibration system is excited by electromagnetic method. The electromagnetic controller inputs a DC voltage to drive electromagnetic high-speed hammer through the DC power source supply. Then the electromagnetic high-speed hammer impacts an airborne hammer, after that, the airborne hammer proceed to impact the PU rubber which is fixed on the end surface of airborne anvil with rigid body motion way. An accelerometer which is mounted on the other end surface of anvil will output the voltage signal during the instantaneous impact. According to different input DC voltage value and different hardness rubber accelerometer will produce different acceleration and duration time. At the same time the accelerometer displacement is measured by combination of modified Michelson and Mach–Zehnder interferometer and acceleration of the accelerometer is derived through two numerical differentiations and two low-pass digital filtering from the displacement. At present the acceleration capability of primary shock calibration system is from 200 m/s2 to 5000 m/s2, the shock pulse duration time is less than 3 ms. The final evaluated relative expanded uncertainty is less than 1.0% within coverage factor k = 1.96. We shall continue to improve and expand the system acceleration from 100 m/s2 to 10,000 m/s2 for various customers in the future.
Characterization of cell death induced by 2‐methoxyethanol in CD‐1 mouse embryos on gestation day 8

Cell death was analyzed in neurulating mouse embryos after in vivo doses of 2-methoxyethanol (2-ME) that produce anterior neural tube defects. Characterization of 2-ME-induced cell death was performed by evaluating: (1) vital fluorochrome staining in whole embryos applying confocal laser scanning microscopy; (2) characteristics of cell debris in conventional histological sections revealed by light microscopy; and (3) Apoptag in situ immunohistochemical staining for apoptosis using light microscopy. Methods for quantification of cell death identified by these three techniques were explored using computerized image analysis. Physiological cell death in control embryos primarily occurred in the neural crest region during neural fold elevation. Embryos exposed to 2-ME had expanded areas of cell death in the neural crest and also new areas of cell death in medial regions of the anterior neural tube. Both physiological and 2-ME-induced embryonic cell death had morphological, immunohistochemical, and fluorochrome staining characteristics of apoptosis. When fluorescence data from confocal microscopic analysis of vital fluorochrome-stained embryos were analyzed, a dose-dependent increase was found in embryos exposed to 2-ME. Similar results were obtained when cell death was analyzed in either conventional histological sections or sections prepared for immunohistochemical detection of apoptosis. The cell death data obtained in this study correlate with previously observed near-term malformation rates, suggesting that a quantitative relationship exists between 2-ME-induced embryonic cell death and neural tube defects.
Distance-to-default measures and determinants for systemically important financial institutions

Purpose – This study aims to compare two distance-to-default methods, data-transformed maximum likelihood estimation and “naive”, that are suitable for financial institutions. The links between these measures and asset size, Tier 1 and Tier 2 capital ratios, non-performing assets and operating efficiency have been examined and an alternative default risk measure has been introduced. Most of the market-based distance-to-default measures are not appropriate for banks due to their unique debt structure. Design/methodology/approach – The author has compared two distance-to-default measures and has identified their accounting determinants using Pearson’s correlation and regressions with clustered standard errors. The sample of the US-based systemically important financial institutions covers the period from 2000 to 2010. Findings – Non-performing assets and operating efficiency are found to be statistically and economically significant determinants of both distance-to-default measures. Tier 1 capital ratio is ...
An Evaluation of the Elaboration Model of Instruction from the Perspective of Assimilation Theory.

This paper provides a critical analysis of Merrill & Reigeluth’s "elaboration model of instruction." First, the elaboration model is briefly described, with special focus on the concepts of "sequencing" and "synthesizing." Second, positive features of the theory are discussed, including the authors’ emphasis on making connections between presented material and existing knowledge. Third, critical comments are provided concerning the clarity of the model, the availability of empirical support, and the failure to describe underlying theoretical mechanisms. The final section of the paper explores the relation between the elaboration model of instruction and cognitive theories of learning such as the "assimilation theory."
Nitric oxide–cyclic GMP signaling in stem cell differentiation

The nitric oxide-cyclic GMP (NO-cGMP) pathway mediates important physiological functions associated with various integrative body systems including the cardiovascular and nervous systems. Furthermore, NO regulates cell growth, survival, apoptosis, proliferation, and differentiation at the cellular level. To understand the significance of the NO-cGMP pathway in development and differentiation, studies have been conducted both in developing embryos and in stem cells. Manipulation of the NO-cGMP pathway, by employing activators and inhibitors as pharmacological probes, and genetic manipulation of NO signaling components have implicated the involvement of this pathway in the regulation of stem cell differentiation. This review focuses on some of the work pertaining to the role of NO-cGMP in the differentiation of stem cells into cells of various lineages, particularly into myocardial cells, and in stem cell-based therapy.
Stable isotopic composition of precipitation in the semi-arid north-central portion of the US Great Plains

Abstract Where data are available, hydrologic studies may use stable oxygen and hydrogen isotopes to investigate, groundwater/surface water interaction, groundwater recharge and advective/diffusive transport, to estimate groundwater ages or to unravel paleohydrology. Such studies require that the isotopic composition of precipitation be known, as precipitation is a major input to groundwater and surface water systems. Oxygen-18 ( δ 18 O) and deuterium ( δ 2 H) data for precipitation are lacking for the semi-arid portion of the north-central Great Plains of the US, and thus there is need to establish additional meteoric water lines as isotope input functions across the region, as well as to develop better understanding of the isotopic climate linkages that control oxygen and hydrogen isotope ratios in precipitation. This study examines the δ 18 O and δ 2 H composition of precipitation for a representative site near North Platte, Nebraska in the semi-arid north-central Great Plains during the years 1989 through 1994. Oxygen-18 values range from −30.5 to +1.7‰. Deuterium values range from −228 to +11‰. Yearly arithmetic mean values for the North Platte station are −9.8 and −71‰, respectively. Weighted yearly means for δ 18 O and δ 2 H over the 6-year period were −9.6 and −69‰, respectively. North Platte values show a strong isotopic enrichment between winter and summer precipitation, and a strong δ 18 O– T correlation r 2 =0.845 for mean monthly values of 0.54‰ per degree Celsius. The local meteoric water line for the site is δ 2 H=7.66 δ 18 O+4.96.
On the Internal Rate of Return Criterion

ABSTRACT Several different procedures for the implementation of the internal rate of return criterion are presented in the literature on investment projects evaluation. Taking the net present worth criterion as a basis for comparison, a survey of some of the suggested procedures and a critique of their theoretical basis are presented. It is showed that, although leading to a proper evaluaticn, they are internally inconsistent in the sense of incorporating modifications that may not really be necessary. To circumvent this possibility, we are going to suggest a conceptual algorithm that should be implemented if we are concerned with the formal application of the internal rate of return criterion.
Lack of periconceptional vitamins or supplements that contain folic acid and diabetes mellitus-associated birth defects.

Objective The purpose of this study was to examine the risk of birth defects in relation to diabetes mellitus and the lack of use of periconceptional vitamins or supplements that contain folic acid. Study Design The National Birth Defects Prevention Study (1997-2004) is a multicenter, population-based case-control study of birth defects (14,721 cases and 5437 control infants). Cases were categorized into 18 types of heart defects and 26 noncardiac birth defects. We estimated odds ratios for independent and joint effects of preexisting diabetes mellitus and a lack of periconceptional use of vitamins or supplements that contain folic acid. Results The pattern of odds ratios suggested an increased risk of defects that are associated with diabetes mellitus in the absence vs the presence of the periconceptional use of vitamins or supplements that contain folic acid. Conclusion The lack of periconceptional use of vitamins or supplements that contain folic acid may be associated with an excess risk for birth defects due to diabetes mellitus.
Characteristics of Induction Conveyor Motors in the Generating mode

In a downhill conveyor system, the drive motors become generators feeding real power to the electrical system. A general method using the cascade network concept and a digital computer is proposed to study the conveyor motors' operation in the motoring and generating modes. By use of the proposed method, a long downhill conveyor system with many stages of induction conveyor motor is studied. Various parameters are considered such as different types of feeder, the amount of shunt capacitor, and the amount of local load in parallel with the conveyor motors. Based on the computed results for the various cases, the electrical performance of a typical downhill conveyor system is summarized. From that, some engineering considerations are proposed to facilitate the design of a technically and economically sound downhill conveyor system. In particular, the conclusion may be drawn that the use of a cable feeder has many advantages, i.e., flat voltage profile along the feeder, relatively low line current and conductor loss, and avoidance of shunt capacitors. Furthermore, it is feasible to interconnect two substations when the conveyor motors are in the generating mode. The power (real and reactive) flow from the generators toward the two substations is affected by differences in the magnitude and angle of the voltage at each substation.