cssi/SciSciGPT-SciSciNet huggingface dataset:
Doppler spread estimation in mobile communication systems

A new technique based on the auto-correlation function is described for the estimation of the Doppler spread in mobile communication systems. We first propose to divide a uncertainty region of Doppler spread into multiple frequency bins. Based on the given multiple bins the correlator compares the estimated value at a certain time index to the theoretical exact value and then decides which bin the Doppler spread is estimated in. The certain time index can be optimized to give the largest decision region among multiple bins. We derive the optimum time index algorithm to give the largest decision region for each bin based on Rayleigh fading channel. We also apply the same Doppler spread estimator to the Rician case with the slight transformation of the received signal. We show that the proposed technique is not affected significantly by the Rician factor and the SNR degradation with the reasonable number of samples for estimation which is not the case of other estimators given in the literature.
Self-consistent theory of mean-field electrodynamics.

Mean-field electrodynamics, including both [alpha] and [beta] effects while accounting for the effects of small-scale magnetic fields, is derived for incompressible magnetohydrodynamics. The principal result is [alpha]=([alpha][sub 0]+[beta][sub 0][bold R][center dot][del][times][bold R])/(1+[ital R][sup 2]), [beta]=[beta][sub 0]; where [alpha][sub 0],[beta][sub 0] are conventional kinematic dynamo parameters, the reduction factor is proportional to the mean magnetic field [bold R]=[ital R][sub [ital m]][sup 1/2][bold B]/([rho][ital V][sup 2])[sup 1/2], [ital R][sub [ital m]] is the magnetic Reynolds number, and [ital V] is the characteristic turbulent velocity. This result follows from a generalization of the Zeldovich theorem to three dimensions, exploiting magnetic helicity balance.
AC Field Induced Polarization Disordering in The Ferroelectric Phase Of Modified Pzt Ceramics

Pronounced nonlinear enhancements in dielectric responses and decreases in phase transformation temperatures were induced under moderate ac fields and high field cycling for La modified lead zirconate titanate (PZT) ceramics. Polarization disordering could be inhibited by introducing acceptor dopants into La modified PZT compositions and by DC bias field. Analysis of the frequency dispersion revealed that the field driven transformation in lower La content PZT is a field assisted activation process, while the transformation in higher La content PZT relaxors is intrinsically a thermal activated process.
Developmental differences in post-lesion axonal growth in the hippocampus.

Abstract The effects of lesions of the entorhinal cortex on the distribution of the commissural projections to dentate gyrus and hippocampus were studied with the Fink-Heimer techniques in immature and mature rats. Early entorhinal lesions caused a hyperdevelopment of the commissural system in both areas while lesions in adults produced similar but quantitatively smaller effects. Two types of post-lesion growth were observed: (1) an increase of the density of innervation in areas normally occupied by commissural fibers, and (2) a movement of commissural fibers into dendritic areas in which they are not found in normal rats.
Arylacetamide κ opioid receptor agonists with reduced cytochrome P450 2D6 inhibitory activity

Abstract Some κ opioid receptor agonists of the arylacetamide class, for example, ICI 199441 (1), were found to strongly inhibit the activity of cytochrome P450 2D6 (CYP2D6) (1: CYP2D6 IC50 = 26 nM). Certain analogs bearing a substituted sulfonylamino group, for example, 13, were discovered to have significantly reduced CYP2D6 inhibitory activity (13: CYP2D6 IC50 > 10 μM) while displaying high affinity toward the cloned human κ opioid receptor, good κ/δ and κ/μ selectivity, and potent in vitro and in vivo agonist activity.
Some Growth Factors Stimulate Cultured Adult Rabbit Ventricular Myocyte Hypertrophy in the Absence of Mechanical Loading

Cultured adult rabbit cardiac myocytes treated with recombinant growth factors display enhanced rates of protein accumulation (ie, growth) in response to insulin and insulin-like growth factors (IGFs), but epidermal growth factor, acidic or basic fibroblast growth factor, and platelet-derived growth factor failed to increase contractile protein synthesis or growth of the heart cells. Insulin and IGF-1 increased growth rates by stimulating anabolic while simultaneously inhibiting catabolic pathways, whereas IGF-2 elevated growth modestly by apparently inhibiting lysosomal proteolysis. Neutralizing antibodies directed against either IGF-1 or IGF-2 or IGF binding protein 3 blocked protein accumulation. A monoclonal antibody directed against the IGF-1 receptor also inhibited changes in protein turnover provoked by recombinant human IGF-1 but not IGF-2. Of the other growth factors tested, only transforming growth factor-beta 1 increased the fractional rate of myosin heavy chain (MHC) synthesis, with beta-MHC synthesis being elevated and alpha-MHC synthesis being suppressed. However, the other growth factors were able to modestly stimulate the rate of DNA synthesis in this preparation. Bromodeoxyuridine labeling revealed that these growth factors increased DNA synthesis in myocytes and nonmyocytes alike, but the heart cells displayed neither karyokinesis or cytokinesis. In contrast, cocultures of cardiac myocytes and nonmyocytes and nonmyocyte-conditioned culture medium failed to enhance the rate of cardiac MHC synthesis or its accumulation, implying that quiescent heart cells do not respond to "conditioning" by cardiac nonmyocytes. These findings demonstrated that insulin and the IGFs promote passively loaded cultured adult rabbit heart cells to hypertrophy but suggest that other growth factors tested may be limited in this regard.
Turbulent separated flow in the vicinity of a single-slotted airfoil flap

Detailed measurements of pressure and velocity characteristics are presented and analyzed for flow over and downstream of a NACA 4412 airfoil equipped with a NACA 4415 single-slotted flap at high angle of attack and close to maximum lift. The flow remained attached over the main element while a large region of recirculating flow occurred over the aft 61 percent of the flap. The airfoil configuration was tested at a Mach number of 0.09 and chord based Reynolds number of 1.8 x 10 to the 6th in the NASA Ames Research Center 7- by 10-Foot Wind Tunnel. Measurements of mean and fluctuating velocities were obtained in the region of recirculation and high turbulence intensity using three-dimensional laser velocimetry. In regions where the flow had a preferred direction and relatively low turbulence intensity hot-wire anemometry was used. Emphasis was placed on obtaining flow characteristics in the confluent boundary layer, the region of recirculating flow and in the downstream wake. Surface pressure measurements were made on the main airfoil, flap, wind tunnel roof, and wind tunnel floor. In addition to the presentation of pressure and velocity characteristics, the near wall results inside the separated region are analyzed as are the relative importance of terms in the momentum and turbulence kinetic energy equations in the confluent separated boundary layer and the recirculating region of the near wake.
NOx formation in flat, laminar, opposed jet methane diffusion flames

It is shown that the detailed structure of a flat laminar opposed jet diffusion flame can be modeled, by properly coupling the momentum and energy conservation equatins and by using detailed finite rate combustion kinetics. Such a flame is one dimensional (for a given stretching rate) provided that the proper velocity boundary conditions, which are a result of the model are employed. A laboratory CH 4 /N 2 /O 2 opposed jet diffusion flame was realized and gave good agreement with predictions with respect to both, one dimensinality and the temperature and species profiles within the reaction zone. However, the actual location of the reaction zone was displaced by a small distance. The theoretical/experimental tool developed was utilized to test kinetic mechanisms of NO formation from fuel nitrogen. In this case, anhydrous ammonia was introduced first with the fuel and then with the oxidizer. The formation of NO was well predicted, using a detailed kinetic mechanism developed by others, when ammonia was introduced with the fuel, but agreement was poor when ammonia was injected in the air side. This indicates that there are some deficiencies in the ammonia pyrolysis kinetic mechanism when it is utilized in the absence of hydrocarbon fragments. The qualitative dependence of the NO profile on flame stretching was correctly predicted by the model. This also allowed the prediction of reaction zone thickness and the rate of formation of NO as a function of stretching rate and these results can be related to NO formation in strained laminar diffusion flamelets as they occur in turbulent diffusion flames.
High level language debugging with a compiler

In this paper, we start from the basic premise of wanting an interactive high level language debugger, and we explore the possibilities of achieving this using a compiler. We outline the functional capabilities desired, and suggest means of achieving them using a compiler. Most of these entail requirements on the compiler, and our suggestions may be viewed as justification for modularizing compiler design.
Soluble Narrow Band Gap and Blue Propylenedioxythiophene-Cyanovinylene Polymers as Multifunctional Materials for Photovoltaic and Electrochromic Applications

A family of soluble narrow band gap donor-acceptor conjugated polymers based on dioxythiophenes and cyanovinylenes is reported. The polymers were synthesized using Knoevenagel polycondensation or Yamamoto coupling polymerizations to yield polymers with molecular weights on the order of 10 000-20 000 g/mol, which possess solubility in common organic solvents. Thin film optical measurements revealed narrow band gaps of 1.5-1.8 eV, which gives the polymers a strong overlap of the solar spectrum. The energetic positions of the band edges were determined by cyclic voltammetry and differential pulse voltammetry and demonstrate that the polymers are both air stable and show a strong propensity for photoinduced charge transfer to fullerene acceptors. Such measurements also suggest that the polymers can be both p- and n-type doped, which is supported by spectroelectrochemical results. These polymers have been investigated as electron donors in photovoltaic devices in combination with PCBM ([6,6]-phenyl C(61)-butyric acid methyl ester) as an electron acceptor based on the near ideal band structures designed into the polymers. Efficiencies as high as 0.2% (AM1.5) with short circuit current densities as high as 1.2-1.3 mA/cm(2) have been observed in polymer/PCBM (1:4 by weight) devices and external quantum efficiencies of more than 10% have been observed at wavelengths longer than 600 nm. The electrochromic properties of the narrow band gap polymers are also of interest as the polymers show three accessible color states changing from an absorptive blue or purple in the neutral state to a transmissive sky-blue or gray in the oxidized and reduced forms. The wide electrochemical range of electrochromic activity coupled with the strong observed changes in transmissivity between oxidation states makes these materials potentially interesting for application to electrochromic displays.
Guest Editorial: Extreme Ultraviolet Interference Lithography

This PDF file contains the editorial “Guest Editorial: Extreme Ultraviolet Interference Lithography” for JM3 Vol. 8 Issue 02
Design and Analysis of Braid-Twist Collagen Scaffolds

Collagen type I fiber-based scaffolds for anterior cruciate ligament (ACL) replacement were evaluated for their mechanical properties and their ability to promote cellular proliferation. Prior to scaffold formation, two crosslinking methods were investigated on individual reconstituted collagen type I fibers, ultraviolet radiation, and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC). Crosslinking with EDC for 4 hr yielded mechanical properties similar to the human ACL; therefore, scaffold crosslinking was done with EDC for 4 hr. A braid-twist scaffold design was used, and scaffolds were left uncrosslinked, crosslinked after the addition of gelatin, or crosslinked without gelatin. The ultimate tensile strength, Young's modulus, and viscoelastic properties of the scaffolds were then evaluated. In order to assess cellular response on the scaffolds, primary rat ligament fibroblast cells were seeded upon the scaffolds. Cell activity was evaluated at days 7, 14, and 21 using a Cell Titer 96(®) AQueous One Solution Cell Proliferation Assay (MTS Assay). The mechanical testing results showed that among the three scaffold groups, the crosslinked scaffolds without gelatin displayed an ultimate tensile strength, Young's modulus, and viscoelastic properties that were closest to the human ACL. Improvements are still desired to enhance the mechanical compliance and ductility of these scaffolds. Cell activity was observed on all cell-seeded scaffolds by day 7, but by day 21 only the crosslinked scaffolds without gelatin displayed increased cellular activity compared with the negative controls. Although improvement is still needed, the results suggest that these scaffolds have the potential to contribute toward an ACL replacement strategy.
Toxic and teratogenic effects of chemical class fractions of a coal-gasification electrostatic precipitator tar

Dimethyl sulfoxide slurries of a coal gasifier electrostatic precipitator tar and its chemical class fractions were assayed for their toxicity and teratogenicity using early embryos of the frog Xenopus laevis. Of the 5 tar fractions the ether-soluble base and polyaromatic were found to be the most teratogenic and the ether-soluble acid and ether-soluble base were the most toxic. The teratogenic effects of the raw tar suggest synergism. The toxic effects to newly metamorphosed froglets is 1–2 orders of magnitude less than those observed for embryos. Chemical analysis shows dihydroxybenzenes and organonitrogen compounds to be the major components of the acid and base fractions, respectively. The neutral fractions contain mainly alkyl-substituted two-ring hydrocarbons.
The movement of the prospective eye vesicles from the neural plate into the neural fold in Ambystoma mexicanum and Xenopus laevis

Abstract Excision experiments performed on amphibian neurulae by H. Spemann (1901, Verh. Anat. Ges. 15, 61–79) and W. H. Lewis (1907, Amer. J. Anat. 7, 259–276) have localized the eye primordia in the anterior neural plate. This was confirmed by the results of the classical vital dye mapping studies by E. Manchot (1929, Wilhelm Roux Arch. Entwicklungsmech. 116, 689–709) and ( M. W. Woerdeman, 1929, Wilhelm Roux Arch. Entwicklungsmech. 116, 220–241) . Spemann published a figure which might suggest that the prospective eye vesicles are still located in this position when the neural folds are present. This paper shows that the eye primordia move from the anterior neural plate into the forming neural folds. This result was obtained by time-lapse photography and excision experiments. Grafting experiments exchanging presumptive optic tissue between wild-type and albino embryos were also performed.
Postdural puncture headache.

Postdural puncture headache (PDPH) has been a problem for patients, following dural puncture, since August Bier reported the first case in 1898. His paper discussed the pathophysiology of low-pressure headache resulting from leakage of cerebrospinal fluid (CSF) from the subarachnoid to the epidural space. Clinical and laboratory research over the last 30 years has shown that use of small-gauge needles, particularly of the pencil-point design, is associated with a lower risk of PDPH than traditional cutting point needle tips (Quincke-point needle). A careful history can rule out other causes of headache. A postural component of headache is the sine qua non of PDPH. In high-risk patients , for example, age < 50 years, postpartum, large-gauge needle puncture, epidural blood patch should be performed within 24–48 h of dural puncture. The optimum volume of blood has been shown to be 12–20 mL for adult patients. Complications of AEBP are rare.
Powered and nonlinear RF metamaterials

The electromagnetic properties of metamaterials can be engineered to achieve substantially more flexibility and variety than those available from conventional materials. Adding some degree of external control or power to metamaterials enables another level of functionality. We describe our recent efforts to develop an approach for realizing powered and nonlinear metamaterials in which each unit cell contains embedded active or nonlinear elements. We demonstrate experimentally how such active and nonlinear metamaterials enable properties such as gain, nonreciprocity, and phase conjugation.
Multi-class decision-theoretic rough sets

As a natural extension to rough set approximations with two decision classes, this paper provides a new formulation of multi-class decision-theoretic rough sets. Instead of making an immediate acceptance or rejection decision, a third option of making a deferment decision is added to each class. This gives users the flexibility of further examining the suspicious objects, thereby reducing the chance of misclassification. Different types of misclassification errors are treated separately based on the notion of loss functions from Bayesian decision theory. The losses incurred for making deferment and rejection decisions to each class are also considered. The presented approach appears to be well suited for cost-sensitive classification tasks where different types of classification errors have different costs. The connections and differences with other existing multi-class rough set models are analyzed.
Magnetic resonance imaging of solid urethral and peri-urethral lesions

Solid urethral and peri-urethral lesions are rare and encompass benign and malignant aetiologies. A diagnosis without imaging is often challenging secondary to non-specific clinical symptoms and overlapping findings at the time of physical examination. Magnetic resonance (MR) imaging may be helpful in confirming a diagnosis while providing anatomical detail and delineating disease extent. This article reviews the normal MR anatomy of the male and female urethra, the MR appearance of solid primary and secondary urethral lesions, and the MR appearance of solid urethral lesion mimics. Teaching points • MRI is an important imaging technique in the evaluation of the spectrum of solid urethral lesions. • With excellent soft tissue resolution, MR is accurate in staging primary urethral carcinoma. • Disruption of the zonal anatomy of the female urethral wall indicates peri-urethral extension. • Be aware of benign urethral lesions, particularly those that may mimic solid urethral masses.
Theoretical Investigation of the Directional Electron Transfer in 4-Aminonaphthalimide Compounds†

Photoinduced electron-transfer reactions in small supramolecular systems, such as the 4-aminonaphthalimide compounds, are interesting in that there are two alternative directions for the electron transfer to occur. Nevertheless, the electron transfer occurs only along one path, as deduced from pH-dependent fluorescence quenching studies of selected compounds. The role of the electronic coupling matrix element and the effect of the charges accompanying protonation are considered so as to explain the directionality of the electron transfer and other results. A related mechanism is suggested for interpreting the behavior of similar molecules, which serve as fluorescent sensors of metal ions.
A Green's function method for multiple-spectra fermion systems: 3 He surface states on 4 He films

A Green's function method for multiple-spectra fermion systems is applied to3He surface states on superfluid4He films to accommodate the multiple transverse3He states. A matrix form of the Dyson equation indexed by the transverse states is inverted to obtain the Green's function matrix in terms of the self energy matrix. Results are shown through the Hartree-Fock approximation.
What Is the Risk of Clinical Anastomotic Leak in the Diverted Colorectal Anastomosis

The objective of this study was to identify clinical leak in diverted colorectal anastomoses. Cohort analysis. The study was conducted in a subspecialty practice at a tertiary care facility. Consecutive subjects undergoing colorectal anastomosis and proximal fecal diversion between July 16, 2007 and June, 31 2012. No intervention was applied. Clinical anastomotic leak. Two hundred forty-five patients underwent a colorectal anastomosis with proximal fecal diversion. A total of 34 (14 %) clinical leaks were identified at a median of 43 days. Clinical leaks were identified in 13 (5 %) patients within 30 days of surgery (early leaks) and in 21 (9 %) patients after 30 days of surgery (late leaks). Age, sex, use of neoadjuvant chemoradiotherapy, and method of anastomotic construction were similar in patients with clinical leaks as compared to those with no evidence of leak. However, clinical leaks were more likely to develop in patients with a diagnosis of inflammatory bowel disease or other diagnoses, i.e., radiation enteritis, ischemia, and injury/enterotomy. Patients with clinical leak were not more likely to have air leaks on intraoperative air leak testing. In diverted anastomoses, most leaks become clinically apparent beyond 30 days. The standard practice of censoring outcomes that occur beyond postoperative day 30 will fail to identify a substantial fraction of leaks in diverted colorectal anastomoses.
Cytogenetic, cellular, and developmental consequences of cryopreservation of immature and mature mouse and human oocytes

This study examined the effects of cryopreservation on cellular organization, chromosomal complement, and developmental potential of immature and mature mouse and human oocytes. Chromosomal analyses were performed by DNA fluorescence microscopy and karyotyping on the same metaphase II-stage oocytes before and after freezing. Cellular analyses involved electron microscopy, time-lapse video recording, and fluorescent-probe microscopy of cortical granules. The findings demonstrate that while profound cytoplasmic, nuclear, and nucleolar alterations occur in the immature oocyte during cryopreservation, an apparently normal nucleus and cytoplasm is re-established progressively after thawing and culture. The resulting oocytes mature at high frequency and for the mouse, are fertilizable and capable of normal preimplantation of embryogenesis. Cryopreservation of mature mouse and human oocytes is not accompanied by a significant increase in the frequency of aneuploidy. However, cryopreserved human oocytes, while fertilizable, arrest development during the early cleavage stages and display aberrant patterns of cytokinesis. The possible etiologies of developmental failure in the human embryo that may be related to oocyte cryopreservation, as well as the potential benefits of cryopreservation of the immature oocyte, are discussed with respect to clinical and commercial applications. © 1994 Wiley-Liss, Inc.
Nuclear magnetic resonance spectral analysis and molecular properties of berberine

An extensive theoretical study of berberine has been performed at the ab initio HF/6-31G**, HF/6-311G**, and B3LYP/6-311G** levels with and without solvent effects. The optimized structures are compared with X-ray data. We found that the optimized structures with solvent effects are in slightly better agreement with X-ray data than those without solvent effects. The 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of berberine were calculated by using the gauge-independent atomic orbital (GIAO) (with and without solvent effects), CSGT, and IGAIM methods. The calculated chemical shifts were compared with the two-dimensional NMR experimental data. Overall, the calculated chemical shifts show very good agreement with the experimental results. The harmonic vibrational frequencies for berberine were calculated at the B3LYP/6-311G** level. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Analysis of bundle losses in high speed machines

Elevated frequencies in high-speed ac machines increase the skin effect in stator windings, making it necessary in many cases to divide each phase winding into high numbers of small-diameter strands connected in parallel. Unfortunately, circulating currents among the strands in a single bundle can significantly increase the total copper losses depending on several factors including the twisting (i.e., transposition) of the strands in the bundles. An analytical model for these bundle proximity losses is presented for individual bundles as well as slot-bound bundles configured for high-speed machines. Loss predictions provided by this model match well with finite element results for high-speed operation of a 55 kW (peak) PM machine with concentrated windings. Stators with litz and non-transposed windings are compared to highlight the large differences in their bundle proximity losses. Analytical and finite element results are shown to match well with experimental results at frequencies of 700 and 800 Hz.
Does franchising pay? Evidence from the restaurant industry

Franchising has taken a prominent position in service industries for several decades, but little is known about how franchising affects financial performance. Thus, we addressed the question of whether chains that franchise to some extent outperform those that are wholly owned. Then, among chains that franchise, we also addressed the question of whether more franchising is better – that is, whether the proportion of a chain's units that are franchised is associated with superior financial performance. To answer these questions, our study first compares the risk-adjusted performance of franchising vs. non-franchising restaurant firms. Second, it investigates the relationship between franchising propensity and firm financial performance. We considered five different measures of firm financial performance: the Sharpe ratio, the Treynor ratio, the Jensen index, the Sortino ratio, and the upside potential ratio. On comparison of franchising and wholly owned firms, all five measures indicated that franchising f...
Surgical management of early pregnancy failure: history, politics, and safe, cost-effective care

Early pregnancy failure and induced abortion are often managed differently, even though safe uterine evacuation is the goal in both. Early pregnancy failure is commonly treated by curettage in operating room settings in anesthetized patients. Induced abortion is most commonly managed by office vacuum aspiration in awake or sedated patients. Medical evidence does not support routine operating room management of early pregnancy failure. This commentary reviews historical origins of these different care standards, explores political factors responsible for their perpetuation, and uses experience at University of Michigan to dramatize the ways in which history, politics, and biomedicine intersect to produce patient care. The University of Michigan initiated office uterine evacuations for early pregnancy failure treatment. Patients previously went to the operating room. These changes required faculty, staff, and resident education. Our efforts blurred the lines between spontaneous and induced abortion management, improved patient care and better utilized hospital resources.
Segregation during diffusional creep of a binary solid solution

Abstract In the diffusional creep of a substitutional solid solution where the diffusivities of the components are different, there is a transient state in which the vacancy flux uses preferentially those atoms with the higher diffusivity, producing segregation of the components. A mathematical formulation of steady-state diffusional creep of a multicomponent solid solution is obtained and, by using a onedimensional model of diffusional creep, the amount of segregation required to achieve the steady state in a binary solution is evaluated in terms of either the activity coefficients or the thermodynamic factor. A simple rule of thumb to evaluate the amount of the segregation is given and results for ideal and regular solid solutions are obtained.
Cultural and Social Influences on Adolescent Smoking Dissipate by Emerging Adulthood Among Hispanics in Southern California

The aim of the present study was to identify risk factors for smoking among Hispanic adolescents and determine whether these factors continued to influence smoking into emerging adulthood. Data were drawn from 932 Hispanics in the greater Los Angeles area who were surveyed in high school in 2007 and then again in emerging adulthood from 2010 to 2012. Logistic regression assessed the associations between predictors in adolescence and smoking in adolescence while an order one transition logistic model assessed predictors in adolescence and smoking in emerging adulthood. Adult and sibling smoking status, perceptions of smoking, perceived discrimination, and fatalism all influenced smoking in adolescence but not in emerging adulthood. Once Hispanics reach emerging adulthood different tactics to reduce smoking will be needed and are where future research should be directed.
Alongfront Variability of Precipitation Associated with a Midlatitude Frontal Zone: TRMM Observations and MM5 Simulation

Abstract On 19 February 2001, the Tropical Rainfall Measuring Mission (TRMM) satellite observed complex alongfront variability in the precipitation structure of an intense cold-frontal rainband. The TRMM Microwave Imager brightness temperatures suggested that, compared to the northern and southern ends of the rainband, a greater amount of precipitation ice was concentrated in the middle portion of the rainband where the front bowed out. A model simulation conducted using the fifth-generation Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) Mesoscale Model (MM5) is examined to explain the distribution of precipitation associated with the cold-frontal rainband. The simulation reveals that the enhanced precipitation ice production and the implied mean ascent along the central part of the front were associated with a synergistic interaction between a low-level front and an upper-level front associated with an intrusion of high-PV stratospheric air. The low-level front contribu...
Endoscopic Retrograde Cholangiopancreatography with Balloon-Assisted Enteroscope in Patients with Surgically Altered Upper GI Anatomy

Abstract Endoscopic retrograde cholangiopancreatography (ERCP) is technically more challenging in patients with postsurgical anatomy such as Billroth II anastomosis and Roux-en-Y anastomosis, frequently mandating an operative intervention. Currently, ERCP using balloon-assisted enteroscopy (BAE) has become the main approach in patients with complex postoperative anatomy. This article presents the technical aspects of performing ERCP with BAE in patients presenting with complex postsurgical anatomy having biliary problems. ERCP using BAE is feasible in patients with complex postsurgical anatomy, permitting diagnostic and therapeutic interventions in 80% of patients. This article is part of an expert video encyclopedia.
Ethanol vapor processing of titania nanotube array films: enhanced crystallization and photoelectrochemical performance

A significant enhancement in the photoconversion efficiency of anodically grown, thermally annealed titania nanotube array photoanodes was observed when subjected to an ethanol vapor treatment that resulted in improved crystallization. Ethanol vapor treatment of 6 µm long vertically aligned titania nanotube array films initially annealed at 580 °C for 6 h in an oxygen environment, under autogeneous pressure at 140 °C (≈50 psi), resulted in an increase of up to ∼30% in the photoconversion efficiency. A significant improvement in the crystallinity as revealed by glancing angle X-ray diffraction (GAXRD) and Raman spectroscopy studies as well as incident photon to current conversion efficiency (IPCE) is observed in the vapor treated samples.
Stem Cells on Patrol

Hematopoietic stem cells (HSCs) exist in the bone marrow and circulate in the blood. In this issue, Massberg et al. (2007) report that HSCs also travel through the lymphatic system. Furthermore, migration of HSCs—which express Toll-like receptors—allows the recognition of pathogenic molecules in peripheral tissues thereby promoting the local generation of innate immune cells at the site of infection.
Mutation and biochemical analysis of 19 probands with mut0 and 13 with mut− methylmalonic aciduria: Identification of seven novel mutations

Abstract Isolated methylmalonic acidurias (MMA-urias) comprise a group of rare autosomal recessively inherited disorders characterised by accumulation of MMA in urine and other body fluids, resulting from deficient activity of the mitochondrial enzyme methylmalonyl-CoA mutase (MCM). Isolated MMA-uria results from either MCM apoenzyme defects ( mut 0 and mut − ) or defects in synthesis of its cofactor 5-deoxyadenosylcobalamin, i.e. cblA, cblB and cblD-variant 2. To date various studies have identified 171 disease-causing mutations in the MCM gene ( MUT ). We report mutation analysis in 32 probands with mut MMA-uria including 13 probands with a mut − defect. Sixty two of 64 possible mutant alleles were identified, seven of which were novel missense alleles. We found three novel mutations (c.427C>T/p.H143Y; c.862T>C/p.S288P; c.1361G>A/p.G454E) among 19 probands with a mut 0 defect and four novel mutations (c.299A>G/p.Y100C; c.1031C>T/p.S344F; c.1097A>G/p.N366S; c.2081G>T/p.R694L) among 13 probands with a mut − defect. Our study provides evidence that the p.Y100C, p.R108H, p.N366S, p.V633G, p.R694W, p.R694L and p.M700K mutations are associated with a mut − phenotype.
Bases of fuzzy matroids

In this paper we continue our study of fuzzy matroids. We define the notion of a basis for a fuzzy matroid and investigate which properties of crisp matroid bases carry over to the fuzzy case.
Diagnosis and Management of Acute Cholangitis

Acute cholangitis is a potentially life-threatening systemic disease resulting from a combination of infection and obstruction of the biliary tree, secondary to different underlying etiologies. Common causes of cholangitis (eg, gallstones, benign and malignant biliary strictures) are well known. However, others (eg, immunoglobulin-G subclass-4–related sclerosing cholangitis) have been described only recently, are still under evaluation, and need to gain broader attention from clinicians. The diagnosis of acute cholangitis is based on clinical presentation and laboratory data indicating systemic infection, as well as diagnostic imaging modalities revealing signs of biliary obstruction and possibly an underlying etiology. The clinical presentation varies, and initial risk stratification is important to guide further management. Early medical therapy, including fluid resuscitation and appropriate antibiotic coverage, is of major importance in all cases, followed by a biliary drainage procedure and, if possible, definitive therapy of the underlying etiology. The type and timing of biliary drainage should be based on the severity of the clinical presentation, and the availability and feasibility of drainage techniques, such as endoscopic retrograde cholangiopancreatography (ERCP), percutaneous transhepatic cholangiography (PTC), and open surgical drainage. ERCP plays a central role in the management of biliary obstruction in patients with acute cholangitis. Endoscopic ultrasound–guided biliary drainage recently emerged as a possible alternative to PTC for second-line therapy if ERCP fails or is not possible.
Psychedelic and Entactogenic Drugs in the Treatment of Depression

CNS deficiency of 5-hydroxytryptamine (serotonin) has been implicated as a biochemical basis in some forms of depression. Existing drug modalities for treating depression include some with serotonergic effects. Studies suggest that psychedelic drugs are also serotonergic. This may indicate a role for psychedelics in the treatment of depression. Such treatment has already been attempted using psychedelic drugs in both the indoleamine and phenylalkylamine categories. Encouraging results seem to recommend further research, with special emphasis on drugs in the phenylisopropylamine subgroup of phenylalkylamines that are only peripherally psychedelic. Certain of these, called entactogens or empathogens, cause substantially less distortion of normative consciousness than classic psychedelics, such as LSD or mescaline. They could therefore be more easily assimilated into existing psychotherapy approaches, where their function would be to enhance the normal psychotherapeutic process rather than serving a maintenance role as chemotherapeutic agents. Their usefulness in such an application would be mainly at the start of psychotherapy in order to (1) reduce the client's "fear response" that often inhibits ability to deal with repressed traumatic material; (2) facilitate the client's interpersonal communications with the therapist, spouse or significant others; and (3) accelerate formation of a therapeutic alliance between client and therapist.
Insulin-like growth factor-I protects cells from ER stress-induced apoptosis via enhancement of the adaptive capacity of endoplasmic reticulum.

Disruption of endoplasmic reticulum (ER) homeostasis causes accumulation of unfolded and misfolded proteins in the ER, triggering the ER stress response, which can eventually lead to apoptosis when ER dysfunction is severe or prolonged. Here we demonstrate that human MCF-7 breast cancer cells, as well as murine NIH/3T3 fibroblasts, are rescued from ER stress-initiated apoptosis by insulin-like growth factor-I (IGF-I). IGF-I significantly augments the adaptive capacity of the ER by enhancing compensatory mechanisms such as the IRE1α-, PERK- and ATF6-mediated arms of ER stress signalling. During ER stress, IGF-I stimulates translational recovery and induces expression of the key molecular chaperone protein Grp78/BiP, thereby enhancing the folding capacity of the ER and promoting recovery from ER stress. We also demonstrate that the antiapoptotic activity of IGF-I during ER stress may be mediated by a novel, as yet unidentified, signalling pathway(s). Application of signal transduction inhibitors of MEK (U1026), PI3K (LY294002 and wortmannin), JNK (SP600125), p38 (SB203580), protein kinases A and C (H-89 and staurosporine) and STAT3 (Stattic) does not prevent IGF-I-mediated protection from ER stress-induced apoptosis. Taken together, these data demonstrate that IGF-I protects against ER stress-induced apoptosis by increasing adaptive mechanisms through enhancement of ER stress-signalling pathways, thereby restoring ER homeostasis and preventing apoptosis.
X-ray scattering study of ribosomes from Escherichia coli.

Abstract The small-angle X-ray scattering curves for the 70, 50 and 30 s ribosomes from Escherichia coli have been measured. The radii of gyration determined were 125, 77 and 69 A for the 70, 50 and 30 s ribosome, respectively. Measurements of the relative molecular weights from the extrapolated forward-angle scattering indicate that the 30 s subunit has half the molecular weight of the 50 s subunit, but the sum of the 30 and 50 s molecular weight was found to be only 75% of the weight of the 70 s ribosome. This result might be influenced by a tendency for the 70 s particles to aggregate. The 50 s subunit was found to have an RNA or RNA-protein tail that detectably altered the shape of the scattering curve. Estimates of the dimensions of the ribosomes were made by comparing the scattering curves with theoretical curves calculated for uniform density ellipsoids and cylinders. The best fit for the 30 s data was with the curve for an ellipsoid of dimensions 55 A × 220 A × 220 A. The 50 s subunit without the tail fit best with an ellipsoid of dimensions 115 A × 230 A × 230 A. The 70 s ribosome was best approximated by an elliptical cylinder of dimensions 135 A × 200 A × 400 A. A possible model for the 70 s ribosome is discussed.
GABA-like immunoreactivity in the cochlea of the developing mouse.

GABA-like immunoreactivity was studied in surface preparations of cochleas from postnatal developing mice, and GAD-like immunoreactivity was studied in the adult. GABA-positive fibres are already present at birth; they innervate both the inner and outer hair cells and some spiral ganglion cells. The GABA-positive fibres that enter via the intraganglionic bundle send collaterals to the spiral ganglion and to the hair cell region. Fibres that enter along the central processes of spiral neurons end predominantly among the spiral ganglion cells. A few spiral neurons display pericellular rings of GABA-positive boutons at birth. In older animals, the endings occur on a small number of spiral ganglion cells either as rings or as brush formations. The early GABA-positive fibres reach the inner hair cells around the second day and the outer hair cells (of the upper turns only) around the seventh day. In 12-day animals, tunnel fibres arborize in the outer hair cell region; their collaterals make contacts with the outer hair cells within four to eight cell-wide segments, distributing the endings high, up to the reticular plate. In older animals, fibres (both GABA- and GAD-positive) may innervate single vertical rows of outer hair cells. In the maturing and the adult cochlea, the GABA-positive component of the inner spiral bundle is conspicuous and extends along the entire cochlear length, but the innervation of the outer hair cells comprises only the mid and apical turns.
2×2 Matrix summation method for multiple reflections and transmissions in a biaxial slab between two anisotropic media

Abstract An analytic method is developed for the investigation of light propagation in biaxial media and simple formulae are derived for the transmission and reflection matrices from a general biaxial slab embedded in between arbitrarily oriented general ambient and substrate. The method is based on knowing the interface reflection and transmission coefficients and the refractive indices of the eigenwaves inside the slab. Once these are known, the reflection and transmission from the biaxial slab are found in a 2×2-matrix form as a result of matrix sum representing all the multiple reflections at the interfaces. The method is also useful for dealing with a finite number of zigzags.
Dissipative flux motion in YBa2Cu3−xFexO7−δ single crystals

Abstract The dissipative flux motion under magnetic fields has been studied in YBa2Cu3-xFexO7-α (x= 0, 0.04, and 0.13) single cry stals. The thermally activated flux-creep model was used to analyze the resistivity data within the transition region. Temperature and field dependence of the activation energy can be scaled as U(T, H) ∼ (1-T/Tc(H))2/H. In general, the activat ion energy is larger for H|ab-plane than for H ⊥ ab-plane. This effect can account for the relative broadening of the resistive transition in th e two field orientations. The optimum fits to U(T, H) provide values of the anisotropic superconducting parameters Hc2(0) and ξ for our crystals with varying Fe concentration. The crossover temperature that delineates the phase boundary between thermally activated flux-creep processes and flux flow will also be discussed.
Competition for tracer 15N in tussock tundra ecosystems

The objectives of this study were to assess the roles of plant species, time, and site on competition for tracer 15N (without carrier) in tussock tundra ecosystems. Six experimental sites were located in northern Alaska. After one year across the experimental sites, the recovery of 1N by litter (11.3-16.3%) and mosses (5.4-16.4%) was significantly greater than for aboveground vascular plants (2.6-5.0%). 15N recoveries by tundra vascular plants (2.6-5.0%) were low when compared to forest trees (9-25%) which suggest that competition for nitrogen is particularly severe in these colddominated tundra ecosystems. There were no significant differences among sites in 15N recoveries by vascular plants, by mosses, or by litter. There was a statistically significant decline in '5N recovery with time for Vaccinium vitis-idaea and Eriophorum vaginatum between the second and third year. The shallow rooted Vaccinium vitisideae was more highly labeled than the deep rooted Eriophorum vaginatum. Nearness to the source of the applied "1N played a critical role in competition for surface applied nitrogen.
On the well-posed two-body problem in electrodynamics and special relativity II

Abstract The initial segment problem for two interacting charged particles is studied and errors are corrected in the author's previous paper on this problem. An existence/uniqueness theorem hods for the forward extension under retarded interaction; a uniqueness theorem holds for the backward extension and also for time-symmetric interactions. An example is given which shows the difficulties which can arise in backwards extension.
Immortal phenotype of the HeLa variant D98 is recessive in hybrids formed with normal human fibroblasts

Normal human cells such as human diploid fibroblasts (HDF) have a finite proliferative lifespan in culture. Previous studies have shown that the limited lifespan phenotype is dominant in cell hybrids formed by fusion of HDF to at least 23 different kinds of immortal human cells. However, two independent studies reported that hybrid clones formed by the fusion of HDF to the HeLa variant D98 had unlimited division potential. Those results were potentially very important because they implied that a) there is a dominant mechanism for immortalization of human cells in addition to the well-documented recessive mechanism, and b) a dominant mechanism would lend itself to identification of the immortalizing gene. Consequently, we carried out more detailed studies of the behavior of D98 cells in hybrids. Our results indicate that the majority of D98 x HDF hybrid clones exhibit a clear-cut finite proliferative lifespan phenotype. In addition, these hybrid cell populations often give rise to an immortal focus of cells that can be seen to take over the population of mortal cells at the end of their lifespan. This phenomenon reconciles our data with the previous reports of immortal D98 x HDF hybrid clones and leads us to conclude that D98 cells do not express a dominant immortalizing gene.
Phosphorus mobility in a karst landscape under pasture grazing system

La distribution spatiale et la partition des fractions de phosphore dissoutes dans le profil de sol d'un paysage pâture de dolines karstiques ont ete etudiees. Nous avons egalement mesure les fractions de P dans les eaux de surface entrant dans un drain de doline et dans l'ecoulement ressortant du karst drainant le secteur d'etude. Le pâturage a augmente N total, C, et toutes les formes de P de sol. L'orthophosphore inorganique dissous (DPi) etait le plus eleve dans la couche de surface du sol et reduit significativement avec la profondeur. La proportion de phosphore non reactif dissous (DPu) a augmente avec la profondeur de sol. Des changements de DPu en fonction de la position dans le paysage et de la profondeur ont ete etroitement correles avec des changements du carbone organique dissous (DOC) suggerant que la mobilite et le transport du DPu ont ete facilites par le DOC. Un echantillonnage dans le paysage a montre une augmentation de phosphore reactif au molybdate (MRP) et de DPu vers le fond et le centre des dolines. La distribution de DPi et DPu dans l'ecoulement de surface et ce qui se produit lors du transit de l'eau sous terre confirme la valeur significative du DPu transporte dans les eaux souterraines du karst.