cssi/SciSciGPT-SciSciNet huggingface dataset:
Fluorometric High-pressure Liquid Chromatographic determination of Hydrocortisone in Human Plasma

A highly sensitive and specific method for hydrocortisone determination in plasma is described. In this method, an internal standard (Δ4-pregnen-17α,20α,21-triol-3,11-dione) was added to plasma, which was then extracted with a mixture of methylene chloride—ether (60:40). After separation and evaporation of the organic phase, derivatization was carried out with dansylhydrazine. Upon completion of the reaction, the excess dansylhydrazine was reacted with pyruvic acid and a second extraction and evaporation step was performed. The residue was taken up in lOO μl of the high-pressure liquid chromatographic mobile phase, and 5 μl was injected onto a microparticulate silica column. Elution was carried out with an ethylene dichloride-butanol-water (91:8.5:0.5) mobile phase. The effluent was monitored with a fluorescence detector (excitation 240 nm; emission 470-nm cutoff filter). A linear calibration curve was found from 5 to 150 ng/ml with the precision estimated to be ±7% (CV).
Abrasive wear response of nanocrystalline Ni–W alloys across the Hall–Petchbreakdown

Abstract The abrasive wear of nanocrystalline Ni–W alloys with grain sizes of 5–105 nm has been studied using Taber abrasion testing. The wear resistance of the finest grain size specimen is found to be higher than would be predicted based on hardness alone. This deviation from Archard scaling is traced to mechanically-driven structural evolution, consisting of grain growth and grain boundary relaxation, which occurs during wear. Comparison of these observations with previous wear studies suggests that the extent of structural evolution during wear depends on contact stresses and material removalrates.
Heat Capacity in the Normal and Superconducting States and Critical Field of Niobium

The heat capacity of a vacuum-annealed sample of niobium has been determined in the temperature range 1.5 to 30\ifmmode^\circ\else\textdegree\fi{}K. The heat capacity measurements in the normal state below the transition temperature were carried out in magnetic fields up to 4130 gauss. The effect of vacuum annealing on the heat capacity, transition temperature, and critical field was determined in an effort to obtain a so-called ideal superconductor. After the initial annealing, within experimental error, the heat capacity in the superconducting state was found to be independent of further treatment. In the normal state the heat capacity (${C}_{n}$) can be represented by the relation ${C}_{n}=0.0018T+464.4{(\frac{T}{\ensuremath{\theta}})}^{3},$ where $\ensuremath{\theta}$ varies from 256 to 320 degrees depending on the temperature for the best annealed sample. No simple relationship holds for the heat capacity in the superconducting state. The heat capacity data could not be fitted to any existing corresponding state theory for superconductors.The zero-field transition temperature (${T}_{c}$) and the critical field (${H}_{c}$) were found to depend on the extent of annealing. For ${T}_{c}=9.07\ifmmode^\circ\else\textdegree\fi{}$K, ${(\frac{d{H}_{c}}{\mathrm{dT}})}_{T={T}_{c}}=1148$ gauss ${\mathrm{deg}}^{\ensuremath{-}1}$ whereas for ${T}_{c}=9.17\ifmmode^\circ\else\textdegree\fi{}$K, the highest transition temperature measured, ${(\frac{d{H}_{c}}{\mathrm{dT}})}_{T={T}_{c}}=734$ gauss ${\mathrm{deg}}^{\ensuremath{-}1}$. From the heat capacity data $(\frac{d{H}_{c}}{\mathrm{dT}})T={T}_{c}=415$ gauss ${\mathrm{deg}}^{\ensuremath{-}1}$ and ${H}_{0}$, the critical field at absolute zero=1944 gauss. It was not possible by vacuum annealing even at 2100\ifmmode^\circ\else\textdegree\fi{}C to obtain an "ideal" superconductor.
A kinetic investigation of the binding of azo dyes to cyclo-maltohexaose

Abstract The equilibrium constants and rate constants for the formation of azo dye-cyclomaltohexaose complexes have been determined at 26.6° and an ionic strength of 0.15. The effect of changing the substituents on the dyes is explained in terms of the sizes (steric factors) of the substituents and the charges on the substituents
A generalization of the principle of causality, which makes it applicable to evolutionary systems

The principle of causality has traditionally been formulated in terms of the dynamic equations of classical physics. It has been believed that only stable (conservative) systems can be meaningfully studied in this way. The evolutionary systems studied by social scientists and biologists are non-conservative, and so are excluded from the traditional formulation of causality. The author argues that causal laws for non-conservative systems can be meaningfully formulated. An example based on Malthus' population theory is given.
An investigation of the weekend effect during different market orientations

Studies of stock returns over short horizons indicated irregularities in returns, the weekend effect, and consequently the notion of market efficiency has been questioned. Despite extensive research on the weekend effect, little research has been conducted to define the prominence of the seasonal anomaly in Bear markets versus non-Bear markets. In the paper the weekend effect is investigated for daily returns in the Dow Jones Industrial Average (DJIA), the S&P 500, and the NASDAQ for Bear and non-Bear markets. Results support a weekend effect but only during non-Bear market orientations and a possible day-of-the-week effect during Bear and non-Bear markets.
Fungal symbiont effects on dune plant diversity depend on precipitation

Summary Historically, mutualisms have been considered to be less important than antagonisms in affecting the composition of ecological communities. In plant communities, beneficial microbes may feature as keystone mutualists in structuring community composition. Understanding the direction and magnitude of mutualist effects at the community scale may be critical for making accurate predictions on plant responses to climate change, particularly for mutualists that ameliorate climate-induced stressors. Such mitigation could shift outcomes between mutualist-enhanced species diversity and mutualist-reduced diversity, depending on whether a mutualist accelerates habitat modification or competitive exclusion by its partner species. Here, we tested the relative importance and interactive effects of altered precipitation and symbiosis between an epichloid fungal endophyte and a dominant grass species for dune plant communities along the Great Lakes, USA. In 2010, we imposed field manipulations of endophyte presence in the foundation dune grass Ammophila breviligulata in combination with rainout shelters and rainfall additions. We monitored natural rates of colonization by new plant individuals over 3 years. Under the current precipitation regime, endophyte symbiosis in A. breviligulata reduced colonizing plant diversity, species richness and evenness. This effect depended on the amount of precipitation, with the symbiosis having weaker effects on plant diversity under both augmented and reduced rainfall treatments. Despite the overall negative effect of endophyte symbiosis on plant diversity, plant responses to the endophyte were species specific. A federally threatened forb, Cirsium pitcheri, increased in abundance when the symbiosis was present, regardless of precipitation regime. Endophyte symbiosis in A. breviligulata caused minor reductions in the abundance of other grass species; however, augmented precipitation benefited other grasses. Synthesis. We show that microbial mutualisms can have strong effects on community structure in a native ecosystem and that the amount of precipitation has the potential to alter how these keystone species interactions affect community composition. Predictions on future plant community structure, for both restored and native dunes, can be improved by accounting for the presence of fungal symbionts in the foundation plant species.
Compression of optical pulses spectrally broadened by self-phase modulation with a fiber bragg grating in transmission.

We demonstrate experimentally the compression of optical pulses, spectrally broadened by self-phase modulation occurring in the rod of a mode-locked Q-switched YLF laser, with an unchirped, apodized fiber Bragg grating in transmission. The compression is due to the strong dispersion of the Bragg grating at frequencies close to the edge of the photonic bandgap, in the passband, where the transmission is high. With the systems investigated, an 80-ps pulse, which is spectrally broadened, owing to self-phase modulation, with a peak nonlinear phase shift of ΔΦ = 7, is compressed to approximately 15 ps, in good agreement with theory and numerical simulations. The results demonstrate that photonic bandgap structures are promising devices for efficient pulse compression.
Bake oven induced variation of surface chemistry on electrocoat paint : Effect on primer-electrocoat intercoat adhesion

The interplay of bake oven processing environment and surface/interfacial chemistry, and their effect on intercoat adhesion has been investigated for a model primer/electrocoat paint system. X-ray photoelectron spectroscopy (XPS) surface analysis established that a prominent ether component in the C 1s core level spectrum correlated with a polyether-based crater-control additive in the electrocoat that surface-segregates during cure. Laboratory-simulated bake oven experiments confirmed that better adhesion characteristics were realized by removal of this electrocoat overlayer through reaction with nitrogen oxides and high levels of moisture present in the cure environment of production direct-fired ovens. Details of the effect of bake oven atmosphere on cure chemistry for direct- versus indirect-fired ovens are presented.
Three-Dimensional Analysis of Continuously Reinforced Concrete Pavements

Continuously reinforced concrete pavement (CRCP) performance depends primarily on early-age cracks that result from changes in temperature and drying shrinkage. Presented is the behavior of the CRCP due to the temperature change obtained by using a three-dimensional finite element model. The nonlinear effects of the bond-slip between concrete and steel and between concrete and base have been studied. Modeling for the curling effect and for the viscoelastic material characteristics also has been considered. The results from the two-dimensional and three-dimensional models have been compared to verify the possibility of using a two-dimensional model. From this study, it was found that crack width and concrete stress are dependent on the transverse steel arrangement near the edge (longitudinal joint), but they are almost independent in the interior of the slab. The tensile stress occurring at the top of the edge on the transverse steel location can be higher than that occurring at the top of the slab center. This represents the possibility of forming a transverse crack from the edge on the transverse steel location. The two-dimensional model with the plane stress element gives results very close to those of the three-dimensional model, except near the edge.
A two species thermodynamic Preisach model for the torsional response of shape memory alloy wires and springs under superelastic conditions

Abstract In this work, a model to simulate the superelastic response for shape memory alloy wires and springs subjected to torsional loading is constructed by combining thermodynamics principles along with preisach models. Following Doraiswamy et al. (2011) , a Gibbs potential based formulation is employed to separate the thermoelastic response of the shape memory alloys from its dissipative response. The dissipative part is then modeled with a discrete Preisach approach. Rather than beginning with a full three dimensional model and solving for non-homogeneous shear stresses across the specimen cross-section, a “strength of materials” approach that can directly model the torsional response using experimentally measurable quantities such as torque and angle of twist is developed. The model results are verified with experiments performed on shape memory alloy springs at three different temperatures. The model is also used to predict torsion response of shape memory alloy wires at different twists and temperatures using experimental results for only one twist or temperature case respectively. The torsional response for three different wire diameters were predicted using experimental data for one diameter case.
Culturele cognitieve neuroscience

‘Op non-verbale taken zijn de crossculturele verschillen echter minimaal.’ Een dergelijke frase kom ik eens in de zoveel tijd tegen in de (neuro)psychologische assessment handboeken. Tien jaar geleden zou ik deze bewering gewillig geslikt hebben. Nu duik ik af en toe de culturele cognitieve (neuro) science in en die literatuur leert me dat cultuur voor cognitieve varianten en hun neurologische substraten zorgt.
Response of the Hadley Circulation to Climate Change in an Aquaplanet GCM Coupled to a Simple Representation of Ocean Heat Transport

It is unclear how the width and strength of the Hadley circulation are controlled and how they respond to climate changes. Simulations of global warming scenarios with comprehensive climate models suggest the Hadley circulation may widen and weaken as the climate warms. But these changes are not quantitatively consistent among models, and how they come about is not understood. Here, a wide range of climates is simulated with an idealized moist general circulation model (GCM) coupled to a simple representation of ocean heat transport, in order to place past and possible future changes in the Hadley circulation into a broader context and to investigate the mechanisms responsible for them. By comparison of simulations with and without ocean heat transport, it is shown that it is essential to take low-latitude ocean heat transport and its coupling to wind stress into account to obtain Hadley circulations in a dynamical regime resembling Earth’s, particularly in climates resembling present-day Earth’s and colder. As the optical thickness of an idealized longwave absorber in the simulations is increased and the climate warms, the Hadley circulation strengthens in colder climates and weakens in warmer climates; it has maximum strength in a climate close to present-day Earth’s. In climates resembling present-day Earth’s and colder, the Hadley circulation strength is largely controlled by the divergence of angular momentum fluxes associated with eddies of midlatitude origin; the latter scale with the mean available potential energy in midlatitudes. The importance of these eddy momentum fluxes for the Hadley circulation strength gradually diminishes as the climate warms. The Hadley circulation generally widens as the climate warms, but at a modest rate that depends sensitively on how it is determined.
Computational Study of Effect of Potassium Lateral Diffusion and Size of Extracellular Space on Neuronal Synchronization

Previous experimental and simulation results have shown that potassium lateral diffusion can generate mutual interaction between neurons resulting in synchronization. The coupling mediator is extracellular potassium concentration. This concentration is modulated by the size of interstitial space. Yet the effect of extracellular space (ECS) size on the level of synchronization between neurons has not yet been studied. We hypothesize that the neuronal synchronization can be modulated by the size of ECS. To test this hypothesis, a two-cell model embedded in a 3-compartment diffusion system was used. Each neuron was surrounded by interstitial space and immersed in the potassium bath. The simulation results show that as the ECS size decreases, synchronous states between non-identical neurons become asynchronous. Since a reduction of ECS size can be achieved by intensive neuronal activity such as epileptiform activity, the results suggest a possible mechanism for the development of synchronization in the process of sustained neuronal activity generated by potassium lateral diffusion
Techware: Speech recognition software and resources on the web [Best of the Web]

In this issue, "Best of the Web" presents online resources available to tackle the problem of speech recognition. Automatic speech recognition turns spoken audio into a sequence of words. It is an extraordinarily broad and multidisciplinary field, drawing primarily from statistical signal processing, machine learning, and linguistics. Although speech-recognition-oriented applications are essential to the success of the technology and its acceptance in the marketplace, we have excluded them from the scope of this article. We will focus instead on resources that are useful for a beginning apprentice to build the technology that will turn sounds into words.
Inverse optimal adaptive control—The interplay between update laws, control laws, and Lyapunov functions

Approaching the problem of optimal adaptive control as “optimal control made adaptive,” namely, as a certainty equivalence combination of linear quadratic optimal control and standard parameter estimation, fails on two counts: numerical (as it requires a solution to a Riccati equation at each time step) and conceptual (as the combination actually does not possess any optimality property). In this note we present a particular form of optimality achievable in Lyapunov-based adaptive control. State and control are subject to positive definite penalties, whereas the parameter estimation error is penalized through an exponential of its square, which means that no attempt is made to enforce the parameter convergence, but the estimation transients are penalized simultaneously with the state and control transients. The form of optimality we reveal here is different from our work in [Z. H. Li and M. Krstic, “Optimal design of adaptive tracking controllers for nonlinear systems,” Automatica, vol. 33, pp. 1459–1473, 1997] where only the terminal value of the parameter error was penalized. We present our optimality concept on a PDE example—boundary control of a particular parabolic PDE with an unknown reaction coefficient. Two technical ideas are central to the developments in the note: a non-quadratic Lyapunov function and a normalization in the Lyapunov-based update law. The optimal adaptive control problem is fundamentally nonlinear and we explore this aspect through several examples that highlight the interplay between the non-quadratic cost and value functions.
ethnoanatomy in a multilingual community: an analysis of semantic change1

Several languages and dialects have been in intimate contact in Romania over a long period of time. An ethnographic semantic analysis of anatomical terms in a Romanian multiethnic community sheds light on the extent to which the internal structure of words and the nature of the contact between languages influences the degree and nature of borrowing among those languages.
Rearing Hylobius transversovittatus and Cyphocleonus achetes Larvae on Artificial Diets (Coleoptera: Curculionidae)

Hylobius transversovittatus Goeze and Cypho cleonus achetes (Fahraeus) (Coleoptera: Curcu lionidae) are large weevils that share many life history traits. Adults feed above ground on the leaves and shoots of their larval host plants. Fe males oviposit in stems or roots, and larvae bur row into the roots where they feed, complete lar val development, and eventually pupate. Luthrum salicaria L. and L. alatum Pursh (Lyth raceae) are host plants for H. transversovittatus (Blossey 1994), and Centaurea maculosa L., and C. duffusa L. (Centauraceae) are the primary hosts of C. achetes (Stinson et al. 1994). These weevils are known to have a narrow host range and are agents for biological control of weeds. Our initial studies on the development of arti ficial diets for root-feeding biological control agents began with adaptations of the Gast diet (Robertson & Wright 1984). We formulated a fully functional diet for H. transversovittatus that yielded adults with a 35% survival rate (Tomic Carruthers 2007). Here we present an improved diet and handling system that increased H. trans versovittatus survival, and extended use of the diet for other insects. Most of the ingredients in our diet were indus trial grade products obtained from Bio-Serv or di rectly from the producers. Pharmamedia? (Trad ers Protein, Memphis, TN) and common chemical ingredients were ordered from the Sigma-Aldrich Company. The diet was prepared as previously de scribed (Tomic-Carruthers 2007) except for sev eral modifications to facilitate and simplify the process. The improved diet was mixed in 1-L batches with a Cusinart Pro Classic household food processor. Dry ingredients (Table 1) were mixed thoroughly in the food processor with the exception of the vitamins, antibiotic, and agar. Half of the required volume of tap water (65?C) was added to the mixture and blended for 3 min. The remaining water was combined with agar and heated to boiling in a microwave oven before it was added to the mixture in the food processor and blended for 30 s. The vitamins and Aureomy cin (5.5% active) then were added to the mixture at 60?C, followed by blending for another 2 min. Finally, corn oil and HC1 were added and blended for 30 s. The prepared diet was transferred to an automated biscuit maker (Atlas) and dispensed into rearing containers. Uncovered containers were left in a clean air bench for 3 h to cool before covering. Sealed cups were refrigerated until eggs or larvae were added. Table 1. Ingredients for the root weevil diets.
Effects of temperature and salinity on Vibrio vulnificus population dynamics as assessed by quantitative PCR.

The abundance of Vibrio vulnificus in coastal environments has been linked to water temperature, while its relationship to salinity is less clear. We have developed a culture-independent, most-probable-number quantitative PCR approach to examine V. vulnificus population dynamics in Barnegat Bay, N.J. Based on the combined analysis of our results from Barnegat Bay and from the literature, the present data show that (i) V. vulnificus population dynamics are strongly correlated to water temperature and (ii) although the general trend is for V. vulnificus abundance to be inversely correlated with salinity, this relationship depends on salinity levels. Irrespective of temperature, high abundances of V. vulnificus are observed at 5 to 10 ppt, which thus appears to be the optimal salinity regime for their survival. At 20 to 25 ppt, V. vulnificus abundances show a positive correlation to salinity. Unsuccessful attempts to resuscitate V. vulnificus , combined with our inability to detect cells during the winter despite an assay adapted to detect viable but nonculturable (VBNC) cells, suggest that the decline and eventual disappearance of V. vulnificus from the water column during the winter months is due primarily to a significant reduction in population size and is not only the consequence of cells entering the VBNC state. These findings are in line with the hypothesis that the sediment serves as a refuge for a subpopulation of V. vulnificus over the winter and weather-driven mixing events during the spring initiate a summer bloom in the water column.
Daily and circadian regulation of 2-[125I]iodomelatonin binding in the chick brain

The pineal gland and its hormone melatonin are important in the control of circadian rhythms in birds. Recent research has indicated the presence of high affinity melatonin-binding sites in a wide array of avian cerebral structures. In this study melatonin-binding sites were localized and characterized in the brains of 2-week-old chicks using in vitro autoradiography and image analysis of 2-[125I]iodomelatonin (IMEL) binding. The IMEL binding predominated in the major components of the chick's visual and auditory systems. These brain binding sites showed a daily variation in IMEL binding, with a higher density of binding during the daytime. A significant peak in IMEL binding was observed in the late afternoon, Zeitgeber time 10. This rhythm of IMEL binding continued in constant darkness, with the peak at circadian time 10. The amplitude of the peak was increased in constant darkness in all structures, with the exception of the ectostriatum and neostriatum. Scatchard analysis of the binding revealed an ave...
Role of p53, Bax, p21, and DNA-PKcs in radiation sensitivity of HCT-116 cells and xenografts.

Background Molecular factors that dictate tumor response to ionizing radiation in rectal cancer are not well described. Methods We investigated the contribution of p53, p21, Bax, and DNA-PKcs in response to ionizing radiation in an isogeneic colorectal cancer system in vitro and in vivo. Results HCT-116 DNA-PKcs −/− cells and xenografts were radiosensitive compared with wild-type (WT) HCT-116 cells. HCT-116 p53 −/− cells and tumor xenografts displayed a radioresistant phenotype. Separately, p21 or Bax deficiency was associated with a radiosensitive phenotype in vitro and in vivo. In vivo, Bax deficiency led to increased tumor necrosis and decreased microvessel density. In vitro, HCT-116 Bax −/− cells had decreased levels of vascular endothelial growth factor. HCT-116 WT cells had a more radioresistant phenotype after pancaspase inhibition, but pancaspase inhibition did not alter radiosensitivity in HCT-116 Bax −/− cells subjected to ionizing radiation. There was no difference in cell growth in HCT-116 WT cells subjected to transient apoptosis-inducing factor (AIF) inhibition; however, HCT-116 Bax −/− cells treated with AIF siRNA followed by ionizing radiation had a significant survival advantage compared with control-treated cells, implicating AIF in the radiosensitivity of Bax −/− cells. Conclusion These data might be used along with other markers to predict response to radiation in patients with rectal cancer.
Gravity reduction spreadsheet to calculate the Bouguer anomaly using standardized methods and constants

Current standards for reduction of observed gravity to a modeled Bouguer anomaly largely are unregulated and vary among geophysical textbooks, commercial software programs, and academic research spreadsheets available for download from the Internet. Using new standards established by the U.S. Geological Survey (USGS) and the North American Gravity Database Committee, we developed a spreadsheet for reduction of raw data to the Bouguer anomaly and, with the use of terrain correction, the complete Bouguer anomaly. The spreadsheet is available for free download from the Geological Society of America Data Repository. We view the spreadsheet as particularly useful for field data reduction and modeling where Internet access is limited or unavailable.
Variations on truncated multiplication

Truncated multiplication can be used to significantly reduce the power dissipation for applications that do not require correctly-rounded results. This paper presents an efficient method for truncated multiplication called hybrid-correction truncation that utilizes the advantages of two previous methods to obtain lower average and maximum absolute error. Comparisons are presented contrasting power, area, and delay for all three methods compared to standard parallel multipliers. Estimates indicate that hybrid truncated multipliers dissipate slightly less power and consume slightly less area than previous methods for truncated multiplication. In addition, utilization of the hybrid truncation method can provide a method for altering the implementation within certain limits to meet a given precision.
A timestamping method using reduced cost ADC hardware

For many semiconductor devices, time stability and relative time location of electrical events is critical; clocks need to strobe data when the data is valid. This fundamental performance is indicative of both the general quality of manufacture and the suitability of a particular device. Parametric measures might include duty cycle variation, peak-to-peak jitter, RMS jitter and minimum pulse width. As increasingly complex timing generation circuits are implemented with mixed analog and digital technology, more sophisticated testing requires a time sense between events (e.g. cycle-to-cycle jitter, period jitter and deterministic jitter.)
Effective Field Theories of Light Nuclei

Effective field theories have been developed for the description of light, shallow nuclei. I review results for two- and three-nucleon systems, and discuss their extension to halo nuclei.
Adolescents' Perceptions of the Benefits and Risks of Their Own Risk Taking

Currently, there is much interest in the extent to which adolescents engage in risk-taking behavior (RTB), particularly drinking alcohol, smoking cigarettes, and having unprotected sex. However, there is little research on adolescents' perceptions of the benefits and consequences of these and other risk-taking behaviors, or how these perceptions are related to their behavioral involvement. College students were chosen for this study specifically because older adolescents (a) engage in a wide variety of RTBs and (b) have been relatively understudied with regard to RTBs. Using the Risk Involvement and Perception Scale (RIPS) (Parsons, Siegel, & Cousins, in press), researchers asked 26 adolescents ages 18 years to 21 years on two occasions (2 weeks apart) to rate their involvement in and perceptions of the risks and benefits of 19 behaviors representing a wide range of behavioral health risks. The RIPS was developed, pilot tested, and found to be highly reliable and internally consistent. Subjects reported a...
The hydrodynamics of locomotion at intermediate Reynolds numbers: undulatory swimming in ascidian larvae (Botrylloides sp.).

Understanding how the shape and motion of an aquatic animal affects the performance of swimming requires knowledge of the fluid forces that generate thrust and drag. These forces are poorly understood for the large diversity of animals that swim at Reynolds numbers (Re) between 10(0) and 10(2). We experimentally tested quasi-steady and unsteady blade-element models of the hydrodynamics of undulatory swimming in the larvae of the ascidian Botrylloides sp. by comparing the forces predicted by these models with measured forces generated by tethered larvae and by comparing the swimming speeds predicted with measurements of the speed of freely swimming larvae. Although both models predicted mean forces that were statistically indistinguishable from measurements, the quasi-steady model predicted the timing of force production and mean swimming speed more accurately than the unsteady model. This suggests that unsteady force (i.e. the acceleration reaction) does not play a role in the dynamics of steady undulatory swimming at Re approximately 10(2). We explored the relative contribution of viscous and inertial force to the generation of thrust and drag at 10(0) 10(2)) and low (<10(0)) Re, the fluid forces that generate thrust cannot be assumed to be the same as those that generate drag at intermediate Re.
Re-treatment of patients with chronic hepatitis C virus genotype 4 infection with pegylated interferon and ribavirin: a meta-analysis.

Background An estimated 170 million people worldwide are infected with hepatitis C virus (HCV). HCV genotype 4 (HCV-4)—the most prevalent hepatitis C strain in the Middle East and Africa—is difficult to treat, with an estimated sustained virological response (SVR) of 53% when using pegylated interferon and ribavirin (P/R) in treatment-naive patients with HCV-4 infection. In regions where access to direct-acting antivirals is limited, re-treatment of patients who failed therapy with another course of P/R may be an option if the success rate is acceptable. Objectives We aimed to determine the SVR from retreatment with P/R in treatment-experienced patients with HCV-4 infection. Methods We performed a meta-analysis using MEDLINE and EMBASE searches, and by reviewing article bibliographies and abstracts from recent Liver Society Meetings. Original studies featuring at least 10 adult, treatment-experienced patients with HCV-4 infection failing prior interferon-based therapy and receiving subsequent re-treatment with P/R were included. Results 3 studies were included. Overall pooled SVR was 32.7%, or 41/126 patients. No significant heterogeneity existed among the studies. One study reported higher SVR of 50% in previous relapsers, compared with 23% in previous non-responders. Conclusions As expected, treatment-experienced patients achieved lower rate of SVR compared with previously reported SVR for treatment-naive patients with HCV-4 infection. The abysmal rate of success from re-treatment with P/R supports the use of direct-acting antivirals whenever re-treatment is considered, even in resource-limited regions.
Electrostatic Synthesis and Characterization of Pb(ZrxTi1-x)O3 Micro/nano-fibers

Pb(Zr0.48Ti0.52)O3 (PZT) micro/nano-fibers and mats were synthesized from alkoxides using electrostatic deposition. The PZT micro/nano-fibers precursor, a mixture of zirconium npropoxide, titanium isopropoxide, and lead 2-ethylhexanoate, was deposited under the following conditions: tip-screen distance=15cm, voltage drop between tip and screen of 15kV. The deposited fibers and mats samples were sintered for half an hour at 400, 500, 600, 700, and 800δC, respectively. Sintered mats were characterized using x-ray diffraction (XRD), sintered fibers were characterized using optical microscope, scanning electron microscopes (SEM), Raman microscope, and scanning probe microscope (SPM). SEM revealed that micro/nano-fibers have diameters varying from a fraction of a micron to around 10 micrometer. XRD and Raman spectra indicated that the precursors begin to transform into intermediate phase Pb2Ti2O6 at 400δC, whose transformation into the perovskite phase starts at 600δC and ends at 800δC. Scanning probes microscope (SPM), operated in voltage-modulated dynamic contact mode, revealed the spontaneous polarization domains, with diameters ranging from 0.1 to 0.5 micron, in microfibers, confirming their piezoelectricity.
Web search engines

This review looks briefly at the history of World Wide Web search engine development, considers the current state of affairs, and reflects on the future. Networked discovery tools have evolved along with Internet resource availability. World Wide Web search engines display some complexity in their variety, content, resource acquisition strategies, and in the array of tools they deploy to assist users. A small but growing body of evaluation literature, much of it not systematic in nature, indicates that performance effectiveness is difficult to assess in this setting. Significant improvements in general-content search engine retrieval and ranking performance may not be possible, and are probably not worth the effort, although search engine providers have introduced some rudimentary attempts at personalization, summarization, and query expansion. The shift to distributed search across multitype database systems could extend general networked discovery and retrieval to include smaller resource collections with rich metadata and navigation tools. © 1998 John Wiley & Sons, Inc.
A model attention and selection framework for estimation of many variables, with applications to estimating object states in large spatial environments

Robots performing service tasks such as cooking and cleaning in human-centric environments require knowledge of certain environmental states in order to complete tasks successfully. While much effort has gone into developing various estimators for deriving distributions on values of unknown states, less attention has been placed on why the particular estimation problem arises. In this work, I argue that state estimation should no longer be treated as a black box. Estimating large sets of variables is computationally costly; just because a technique exists to estimate the values of certain variables does not justify its application. For robots whose ultimate mission is to complete tasks, only variables that are relevant to successful completion should be estimated. I propose to initially only track a minimal set of directly-relevant variables (attention), and gradually increase the sophistication of models on-demand (refinement), in a local fashion. This estimator refinement process is triggered by violations in expectations of task success (mismatch). This model selection framework is demonstrated through a proof-of-concept case study.
Crustal morphology and plate tectonics in south central Alaska

abstract The geometry of the crust-mantle interface has been determined for south central Alaska using earthquake records from two permanent telemetry networks and temporary stations. A mountain root is found under the Alaska Range. Moho depths and a steeply dipping focal plane suggest that the Aleutian Arc subduction zone continues through Cook Inlet and the Susitna lowlands to the Alaska Range and terminates in a continental setting.
Gastrointestinal Hemorrhage from Duodenal Diverticula Review of the Literature and Report of a Case

O xl~ OF TH~ ~0RE unusual causes of gastrointestinal hemorrhage is bleeding from an inflamed or ulcera~ted diverticulum of the duodenum, s, 14, is, 19 One author 9 has expressed doubt that a divel:ticulum of the duodenum is ever a cause of major gastrointestinal bleeding. The purpose of this commmlication is to preseJlt a review of the literatfire, and to describe a patient in whom massive hemorrhage from a duodenal diverticulum ultimately caused death. The incidence of duodenal diverticula, as found from upper gastrointestinal roentgenographic examinations, ranges from 0.016 to 5.76 per cent. 7 Ill necropsy series, the incidence of this lesion is 0.69 p6r cent. 3. tIowever, when Ackerman strolled plaster of Paris molds of 50 duodenums from cadavers, he found duodenal diverticula in 22 per cent of the specimens. Most symptoms of duodenal diverticula are the result of superficial erosiol~ or ulceration, s, 7, ~4, 23 The symptoms occur in only a small per cent of cases of duodenal diverticula, ~' 13 and there is no characteristic syndrome. Forrest 1~ reported that the most common associated symptom in 69 patients with duodenal diverticula was bleeding, although other possible bleeding sites could be found in many. The incidence of such bleeding is dif~cult to determine, since without surgical or postmortem confirmation one cannot be certain that another lesion is not the cause. Many authors have attributed major gastrointestinal hemorrhage to diverticula because such were the only lesions that could be found on roentgenographic examination. ~,1°'~2,13 However, surgical exploration From the Departments of ~fedicine and Surgery, Northwestern University ~fedical School, and the Veterans Administration Research Hospital, Chicago, Ill. Dr. Lazar is N.I.A.M.D. Trainee in Gastroenferology.
Mitochondrial Gene Expression Is Responsive to Starvation Stress and Developmental Transition in Trypanosoma cruzi

ABSTRACT Trypanosoma cruzi parasites causing Chagas disease are passed between mammals by the triatomine bug vector. Within the insect, T. cruzi epimastigote-stage cells replicate and progress through the increasingly nutrient-restricted digestive tract, differentiating into infectious, nonreplicative metacyclic trypomastigotes. Thus, we evaluated how nutrient perturbations or metacyclogenesis affects mitochondrial gene expression in different insect life cycle stages. We compared mitochondrial RNA abundances in cultures containing fed, replicating epimastigotes, differentiating cultures containing both starved epimastigotes and metacyclic trypomastigotes and epimastigote starvation cultures. We observed increases in mitochondrial rRNAs and some mRNAs in differentiating cultures. These increases predominated only for the edited CYb mRNA in cultures enriched for metacyclic trypomastigotes. For the other transcripts, abundance increases were linked to starvation and were strongest in culture fractions with a high population of starved epimastigotes. We show that loss of both glucose and amino acids results in rapid increases in RNA abundances that are quickly reduced when these nutrients are returned. Furthermore, the individual RNAs exhibit distinct temporal abundance patterns, suggestive of multiple mechanisms regulating individual transcript abundance. Finally, increases in mitochondrial respiratory complex subunit mRNA abundances were not matched by increases in abundances of nucleus-encoded subunit mRNAs, nor were there statistically significant increases in protein levels of three nucleus-encoded subunits tested. These results show that, similarly to that in T. brucei, the mitochondrial genome in T. cruzi has the potential to alter gene expression in response to environmental or developmental stimuli but for an as-yet-unknown purpose. IMPORTANCE Chagas disease is caused by insect-transmitted Trypanosoma cruzi. Halting T. cruzi’s life cycle in one of its various human and insect life stages would effectively stop the parasite’s infection cycle. T. cruzi is exposed to a variety of environmental conditions in its different life stages, and gene expression must be remodeled to survive these changes. In this work, we look at the impact that one of these changes, nutrient depletion, has on the expression of the 20 gene products encoded in the mitochondrial genome that is neglected by whole-genome studies. We show increases in mitochondrial RNA abundances in starved insect-stage cells, under two conditions in which transition to the infectious stage occurs or does not. This report is the first to show that T. cruzi mitochondrial gene expression is sensitive to environmental perturbations, consistent with mitochondrial gene expression regulatory pathways being potential antiparasitic targets.
Metamaterial based narrow bandwidth angle-of-incidence independent transmission filters for hyperspectral imaging

In this work hyperbolic metamaterials are integrated within Bragg transmission ﬁlters with the purpose of eliminating the dependence of the center wavelength of a narrow bandwidth transmission peak on the angle of incidence of the incoming TM polarized beam. The structure is composed of a multi-layer stack of dielectric materials with an array of metal wires vertically penetrating the entire structure. Two types of modeling methods are used to simulate the optical properties of the structure, a coupled wave algorithm that uses a transfer matrix method, and ﬁnite element modeling. It is shown that narrow band transmission ﬁlters can be designed such that the center wavelength of the transmission peak for TM polarized incident light does not change as the angle of incidence of an incoming beam changes. The method is applied to diﬀerent hypothetical structures operating in the near infrared, mid wave infrared and long wave infrared. A structure operating at 1.5GHz is designed.
Effect of citric acid on frozen whole strawberries.

Strawberries are a fragile crop. How should they be processed for freezing and what storage conditions are best for maintaining top quality?
Open source structure-from-motion for aerial video

Structure-from-motion (SfM) is a well-studied problem in the computer vision field and is of particular interest for aerial imaging applications like mapping, terrain modeling, crop monitoring, etc. With the current rapid growth in the commercial UAV and small satellite markets, aerial SfM is becoming even more important. In recent years, free and open source software has enabled almost anyone to apply SfM to their data at no cost. Existing free packages are oriented toward processing unordered collections of photographs and are less efficient at processing ordered collections or video. They are also prone to failure with nearly planar scenes that often arise in aerial photography. While commercial solutions for aerial SfM exist, they are proprietary and expensive. This paper presents a new open source software toolkit named MAP-Tk that targets SfM for aerial video. It exploits temporal continuity and the aerial nature of the data to speed up and improve feature tracking, loop closure, and bundle adjustment. The system is highly configurable and modular. Dynamic plugins provide state-of-the art algorithms from other open source projects like OpenCV, VXL, and Ceres Solver. This paper presents the modular system design, user interface, novel algorithms exploiting aerial video, and results on various aerial data sets.
NSC 68 and the Political Economy of the Early Cold War: The British Sterling-Dollar Crisis of 1949–1950

The UK's collapse is one of the most dramatic events of recent history and the suddenness of that collapse has demonstrated the extent and depth of her former close association in the business and financial structure of Europe. David K. E. Bruce, U.S. Ambassador to France, 1949 United States foreign policy officials and other elites committed to multilateralism viewed the European Recovery Program (ERP), or the Marshall Plan, as a stop-gap measure designed to ease western Europe's dollar gap while more permanent solutions to it could be found. In the summer of 1949, however, it became clear to them that the Marshall Plan was not achieving its desired end as the dollar gap hit Britain with renewed force, causing it to dip into its gold and dollar reserves to purchase badly needed imports and, ultimately, to place trade restrictions on U.S. and other dollar area imports and begin contemplating autarchic solutions to overcome its economic woes. This, even as it was receiving Marshall Plan aid. The British crisis of 1949–1950 served as a wake-up call to Truman administration officials and their British counterparts that the dollar gap was a far more serious crisis than they had realized initially and that if something were not done to overcome it by 1952, the end year of the Marshall Plan, the western world would likely collapse.
Variables and Constants – A Place for Everything and Everything in Its Place

VB Quip There are 10 types of people in the world: those that understand binary and those that don't. On a computer, memory is everything, or nearly so. Data are stored there and programs are loaded and run from memory. Memory is essential. Compared to what was available a few years ago, today's computers have a huge amount of memory. A few years ago that same comparison would have been true as well. Forty years ago we sent men to the moon with spaceships that had less memory than a good pocket calculator has today. All computers, old and new, have memory in common. Memory is where what the computer “knows” is stored. Much of programming comes down to allocating and managing memory. For the PCs of a generation ago, memory was a scarce and expensive commodity to be guarded closely and used judiciously. Programmers used it carefully and squeezed as much as they could from it. At the time, conserving memory gave you a leg up on development and helped make your programs faster and more efficient. And, today, while the amount of memory isn't as much of an issue, the management of memory is. When you work on your computer, you work with its “desktop.” These days, it's the size of a table. In the early days of programming, that “desktop” was the size of a postage stamp. Variables and constants are two important components of a computer program. Both are created in memory and are assigned values.
Symptom burden in heart failure: assessment, impact on outcomes, and management

Evidence-based management has improved long-term survival in patients with heart failure (HF). However, an unintended consequence of increased longevity is that patients with HF are exposed to a greater symptom burden over time. In addition to classic symptoms such as dyspnea and edema, patients with HF frequently suffer additional symptoms such as pain, depression, gastrointestinal distress, and fatigue. In addition to obvious effects on quality of life, untreated symptoms increase clinical events including emergency department visits, hospitalizations, and long-term mortality in a dose-dependent fashion. Symptom management in patients with HF consists of two key components: comprehensive symptom assessment and sufficient knowledge of available approaches to alleviate the symptoms. Successful treatment addresses not just the physical but also the emotional, social, and spiritual aspects of suffering. Despite a lack of formal experience during cardiovascular training, symptom management in HF can be learned and implemented effectively by cardiology providers. Co-management with palliative medicine specialists can add significant value across the spectrum and throughout the course of HF.