cssi/SciSciGPT-SciSciNet huggingface dataset:
Fabrication of symmetric sub-5 nm nanopores using focused ion and electron beams

Nanopores fabricated in solid-state membranes have previously been used for the rapid electrical detection and characterization of single biopolymer molecules. Various methods for producing solid-state nanopores have been reported, but fabricating nanopores of desired sizes controllably is still challenging. Here we report a fabrication technique which uses a focused ion beam (FIB) system to engineer nanopores precisely. This technique provides visual feedback over the formation process. The present method can produce highly symmetrical nanopores with diameters smaller than ~5?nm and can be used to create an array of multiple nanopores simultaneously. In addition, nanopores produced using the focused ion beam sculpting technique can be tailored down to less than 1?nm in diameter using high-energy electron radiation.
Comparison of the Characteristics of Adsorption Equilibrium and Surface Diffusion in Liquid−Solid and Gas−Solid Adsorption on C18-Silica Gels

Four parameters characterizing the adsorption equilibrium, surface diffusion, and related thermodynamic properties were derived from pulse-response experiments in various reversed-phase liquid chromatography (RPLC) systems using C18-silica gels and aqueous solutions of three different organic modifiers, methanol, acetonitrile, and tetrahydrofuran. The results were compared with corresponding data similarly measured by gas−solid chromatography on the same type of surface-modified silica gel, with helium. Information on the solvent effect on the adsorption characteristics was provided by the comparison of these experimental results. While the adsorption equilibrium constant and the heat of adsorption at infinite dilution were much larger in the gas−solid than in the RPLC system, the surface diffusion coefficient (Ds) and the activation energy of surface diffusion (Es) were of the same order of magnitude in both systems. Regarding surface diffusion, the logarithm of the frequency factor was linearly correlat...
Processes of Language Acquisition in Children With Autism: Evidence from Preferential Looking

Two language acquisition processes (comprehension preceding production of word order, the noun bias) were examined in 2- and 3-year-old children (n=10) with autistic spectrum disorder and in typically developing 21-month-olds (n=13). Intermodal preferential looking was used to assess comprehension of subject–verb–object word order and the tendency to map novel words onto objects rather than actions. Spontaneous speech samples were also collected. Results demonstrated significant comprehension of word order in both groups well before production. Moreover, children in both groups consistently showed the noun bias. Comprehension preceding production and the noun bias appear to be robust processes of language acquisition, observable in both typical and language-impaired populations.
A study of stress development in aqueous gelatin coatings

A cantilever deflection technique was used to monitor stress during the drying of aqueous gelatin coatings. Photographic-grade gelatin was dissolved in deionized water and coated, chilled, and dried. The final average in-plane tensile stress ranged from 0 to 50 MPa. Measured stresses were independent of the coating thickness and initial solution concentration. At low relative humidity (0%) and low drying temperature (∼ 20°C), the stress grew with time, reaching a constant average magnitude of 46 MPa. Raising the relative humidity above 0% or raising the temperature above 50°C changed the manner in which stress evolved. Stress rose to a peak value and then relaxed to a lower final value. Humidity affected stress evolution more than did temperature, within the limits of this work. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 553–561, 1999
Simultaneous signaling through investment in an R& D game with private information

Abstract We analyze an R&D game of two-sided incomplete information in which firms can invest in cost reducing technology before engaging in Cournot competition. Investment is observable, but R&D outcomes are not. We focus on partial pooling equilibria in which high cost firms mimic the strategy of low cost firms, resulting in under investment in equilibrium. These equilibria generally involve mixed strategies with the novel feature that players are not indifferent among their mixed strategies due to the beliefs and subsequent actions they induce. Further results suggest that firms may be willing to pay to keep their R& D outcomes concealed.
Omental free flap reconstruction in complex head and neck deformities.

Background Microvascular free flaps continue to revolutionize coverage options in head and neck reconstruction. This article reviews our 25-year experience with omental free tissue transfers. Methods All patients who underwent free omental transfer to the head and neck region were reviewed. Results Fifty-five patients were included with omental transfers to the scalp (25%), craniofacial (62%), and neck (13%) region. Indications were tumor resections, burn wound, hemifacial atrophy, trauma, and moyamoya disease. Average follow-up was 3.1 years (range, 2 months–13 years). Donor site morbidities included abdominal wound infection, gastric outlet obstruction, and postoperative bleeding. Recipient site morbidities included partial flap loss in four patients (7%) total flap loss in two patients (3.6%), and three hematomas. Conclusions The omental free flap has acceptable abdominal morbidity and provides sufficient soft tissue coverage with a 96.4% survival. The thickness \and versatility of omentum provide sufficient contour molding for craniofacial reconstruction. It is an attractive alternative for reconstruction of large scalp defects and badly irradiated tissue. © 2002 Wiley Periodicals, Inc. Head Neck 24: 326–331, 2002; DOI 10.1002/hed.10082
Treatment of social anxiety disorder with citalopram

Selective serotonin reuptake inhibitors (SSRIs) are used as treatment for generalized and specific social phobias (social anxiety disorders). The efficacy of citalopram, an SSRI, for the treatment of social anxiety disorders has not yet been fully evaluated. These cases suggest that citalopram may be an effective treatment for social anxiety disorder (social phobia). These cases are consistent with two other published reports with citalopram from outside the US. Randomized controlled studies are warranted.
The blood-brain barrier protects foreign antigens in the brain from immune attack

To examine the role of the blood-brain barrier (BBB) in maintaining immune privilege in the brain, the BBB in the region of stably integrated mouse neural grafts implanted in neonatal rat brains was transiently disrupted by intracarotid infusion of hypertonic mannitol. This led to graft rejection and to prominent expression of major histocompatibility complex (MHC) antigens on cells adjacent to the graft. Grafts in control animals receiving an intracarotid infusion of isotonic saline showed only rare MHC expression and no increased incidence of rejection. Opening the barrier in the absence of a graft caused neither MHC expression nor cellular infiltration within the brain, suggesting that the effects of the hypertonic infusion were not produced by an indirect injury-mediated effect on the host brain. We conclude that the integrity of the blood-brain barrier is an important factor in the relative immune privilege of nonsyngeneic neural grafts.
Fabrication of high-quality Josephson junctions for quantum computation using a self-aligned process

Quantum computers are believed to have the potential to perform certain tasks much better than conventional computers. Recently, very promising results have been demonstrated with superconducting devices based on Josephson junctions. The quality of the Josephson junctions plays an important role in determining the coherence time of superconducting quantum bits, and hence the viability of superconducting quantum computers. We have developed a self-aligned process for the fabrication of Nb-based Josephson devices. A UVN-30 negative-tone resist is used for both electron beam and photo-lithography. Very high quality Josephson junctions with sizes as small as 0.15 × 0.15 µm2 have been made. This process has a turn around time of 4-5 days which makes it much easier to study different factors affecting the quality of Josephson junctions.
Improved Bounds on the Effective Elastic Moduli of Random Arrays of Cylinders

Improved rigorous bounds on the effective elastic moduli of a transversely isotropic fiber-reinforced material composed of aligned, infinitely long, equisized, circular cylinders distributed throughout a matrix are evaluated for cylinder volume fractions up to 70 percent. The bounds are generally shown to provide significant improvement over the Hill-Hashin bounds which incorporate only volume-fraction information. For cases in which the cylinders are stiffer than the matrix, the improved lower bounds provide relatively accurate estimates of the elastic moduli, even when the upper bound diverges from it (i.e., when the cylinders are substantially stiffer than the matrix). This last statement is supported by accurate, recently obtained Monte Carlo computer-simulation data of the true effective axial shear modulus.
Traumatic Events and Children How Early Childhood Educators Can Help

(2002). Traumatic Events and Children How Early Childhood Educators Can Help. Childhood Education: Vol. 79, No. 1, pp. 2-8.
Academic scientists’ affiliation with university research centers: Selection dynamics

University research centers have been institutionalized as a part of the science policy repertoire committed to strategic use of science and technology. Based on a representative sample of academic scientists and engineers in American research universities, this study investigates the selection dynamics, attempting to unfold the determinants of department-affiliated faculty members to be center affiliates. The findings suggest that university research centers select their affiliates on the basis of individual scientific and technical human capital. Scientists from prestigious departments are more likely to be center affiliates, so are prolific scientists, former postdoctoral scholars and the elder cohorts. In the meantime, university research centers are able to overcome the incentive incongruity with academic departments, as is evidenced by a higher likelihood among junior scientists to secure center connections. Dedicated to diversity and equity, university research centers provide a level playing field for women, minority and foreign-born scientists. The study concludes with a discussion of the scientific and technical human capital theory and policy implications in the science enterprise.
Glycation-induced matrix stability in the rabbit achilles tendon.

Connective tissue susceptibility to nonenzymatic glycation was examined following 0, 2, 4, 6, 8, and 10 weeks of incubating the rabbit Achilles tendon in phosphate-buffered saline containing ribose (glycated). The biomechanical integrity of the glycated tendons was then compared to control tendons incubated in phosphate-buffered saline (nonglycated) at each time interval, while the biochemical stability of both groups of tendons was determined by examining collagen extractability and the formation of pentosidine at 8 weeks. Whereas there were no significant biomechanical differences between control and glycated tendons at 0- and 2-week intervals (P > 0.05), moderately significant increases in maximum load, energy to yield, and toughness of glycated tendons were observed at 4 weeks. Beyond 4 weeks of incubation, the differences between glycated and nonglycated tendons became highly significant, as glycated tendons withstood more load and tensile stress (P < 0.01 for each variable), attained significantly higher modulus of elasticity (P < 0.01), absorbed more energy (P < 0.01), and became tougher (P < 0.01) than controls. These differences in the biomechanical indices of the effects of glycation were stable between the 6th and 10th week of glycation. The maximum increases in the biomechanical measurements as a result of glycation were 29% for maximum load, 125% for stress, 19% for strain, 106% for Young's modulus of elasticity, 14% for energy to yield, and 57% for toughness. Biochemical analysis showed a 61% reduction in the extractability of neutral salt-soluble collagen, a 48% decrease in acid-soluble collagen, and a 29% decline in pepsin-soluble collagen in glycated tendons (P < 0.01). In contrast, there was a 28% increase in the amount of insoluble collagen and significantly higher amounts of pentosidine (P < 0.01) in glycated tendons. Collectively, these biomechanical and biochemical results suggest that nonenzymatic glycation may explain the altered stability of connective tissue matrix induced by the processes of diabetes and aging.
Roll to Roll Processing for Flexible Nanophotonics

This article discusses the current status and achievements of R2R technology for large area nano-scaled optical devices developed at MSL/ITRI. Firstly, a single layer of nanostructure on polymer film is designed for anti-reflection purpose by finite difference time domain (FDTD) method in the visible light spectrum. The conical array with around 1 aspect ratio, like moth-eye shape and showing superior performance in the optical simulation, has been adapted for the R2R experiments. The development of R2R process includes roller machine design and fabrication, roller mold design and making, development of rolling imprint process, characterization of rolled devices. In this study, large area (200mm *200mm) Ni template was fabricated with DUV exposure, followed by dry etching and electroforming process, respectively. Then, the template was bonded on the roller mold with magnetic film to make nanostructure roller mold. With the delicate nanostructure roller mold, systematic experiments have been conducted on the home-made roller machine with various parameters, such as linear speed, dose rate, and material modifications. The duplicated nanostructure films show very good optical quality of anti-reflection (AR < 1%) and are in good agreement with the theoretical predictions. Besides, the duration of the roller mold has been highly promoted to hundreds of imprint in the UV embossing process.Copyright © 2007 by ASME
Parametrization of the driven betatron oscillation

An AC dipole is a magnet which produces a sinusoidally oscillating dipole field and excites coherent transverse beam oscillations in a synchrotron. By observing this driven coherent oscillation, the linear optical parameters can be directly measured at locations of the beam position monitors. The driven oscillations induced by an AC dipole will generate a phase space ellipse which differs from that of free oscillations. If not properly accounted for, this difference can lead to misinterpretations of the actual optical parameters, for instance, 6% or more in the cases of the Tevatron, RHIC, or LHC. This paper shows that the effect of an AC dipole on the observed linear optics is identical to that of a thin lens quadrupole. By introducing a new amplitude function to describe this new phase space ellipse, the motion produced by an AC dipole becomes easier to interpret. The introduction of this new amplitude function also helps measurements of the normal Courant-Snyder parameters based on beam position data taken under the influence of an AC dipole. This new parametrization of driven oscillations is presented and is used to interpret data taken in the FNAL Tevatron using an AC dipole.
Assessment and treatment of acute heart failure—Case study: Wet and cold profile

A 76-year-old African American female was brought to the hospital by ambulance after becoming progressively short of breath at her nursing home. She stated that she awoke that day with a feeling of “smothering” and generally felt short of breath. The patient reported no chest pain, fever, or cough, but did note that her feeling of dyspnea was made worse by lying supine. Records from her nursing home revealed that the patient was currently on furosemide 40 mg daily but was not eating or drinking well. She was initially started on 2 l O2, with no other therapeutics secondary to a recorded blood pressure of 108/78 mmHg.
Fatigue Behavior of VARTM Manufactured Biaxial Braided Composites

Braided composites have good properties in mutually orthogonal directions, more balanced properties than traditional tape laminates, and have potentially better fatigue and impact resistance due to the interlacing. Another benefit is reduced manufacturing cost by reducing part count. Because of these potential benefits braided composites are being considered for various applications ranging from primary/secondary structures for aerospace structures [1]. These material systems are gaining popularity, in particular for the small business jets, where FAA requires taken off weights of 12,500 lb. or less. The new process, Vacuum Assisted Resin Transfer Molding (VARTM), is low cost, affordable and suitable for high volume manufacturing environment. Recently the aircraft industry has been successful in maufacturing wing flaps, using carbon fiber braids and epoxy resin and the VARTM process. To utilize these VARTM manufactured braided materials to the fullest advantage (and hence to avoid underutilization), it is necessary to understand their behavior under different loading and environmental conditions. This will reduce uncertainty and hence reduce the factor of safety in the design. Any typical structural member made of composite material is subjected to different types of loading such as static, impact, cyclic causing fatigue, and environmental effects such as change in temperature and exposure to moisture and other corrosives. It is well known that cyclic loading reduces the strength of a material and its useful life or, the fatigue strength of a material is lower than its static strength. This is true of all materials—metals, plastics, composite materials, etc. In structural applications, fatigue loading is unavoidable especially in aerospace and ground transportation applications. This research addresses the tensiontension fatigue behavior of biaxial braided composites.Copyright © 2003 by ASME
Labor, Politics and Industrialization in the Dominican Republic

The purpose of this article is to trace the development of the Dominican labor movement in the context of the economic and political changes that have taken place in the Dominican Republic since the Trujillo dictatorship. A main objective is to show how the subordinated role of the working class in Dominican society has changed little despite the industrialization process initiated in the 1940s and push forward in the late 1960s, and the establishment of a democratic government in 1978. Both under authoritarian and democratic rule, the Dominican labor movement has been a weak political force, largely exluded from the economic and political benefits associated with industrialization and the modernization of the economy and the political system. This paper does not seek to test theories or hypotheses of labor or political development. In this sense, this article reflects more an attempt to discuss the development of the labor movement and labor relations in the Dominican case than an effort to evaluate theo...
Inhibitory activity of polyamines on phospholipase C from human platelets.

Abstract The calcium-dependent phosphatidylinositol(PI)-specific phospholipase C from human platelets was inhibited by naturally occuring polyamines and synthetic aliphatic alkyldiamines. The inhibitory effectiveness of these substances increased as the number of methylene groups in the molecule increased from 5 to 10. Kinetic studies revealed that the inhibition of phospholipase C by spermine was non-competitive with respect to calcium, but competitive with respect to PI. The data suggest that penetration of the aliphatic chain of alkyldiamines into the hydrophobic tail region of PI vesicles followed by displacement of calcium ions from the lipid polar head group by the cationic amino groups are the key interactions between the amines and PI.
Absolute pitch: Music and beyond

‘‘Perfect pitch,’’ known in the scientific literature as ‘‘absolute pitch’’ (AP), is a rare phenomenon that has fascinated musicians and scientists alike for over a century. There has been a great deal of conflict in the literature between advocates of the two main theories on the etiology of AP: some believe that AP is learned early in life through intensive musical training, whereas others believe AP to be largely innate. Both theories are alike, however, in considering AP to be exclusively a musical phenomenon. We propose a paradigm shift by presenting here a new model of AP, one that is predicated on two principles: (1) that AP may be relatively independent of musical experience; and (2) that there are different types of AP, each of which can be ascribed to discrete neurobiological mechanisms. We also review data from a diverse series of experiments that were designed to test explicitly both the predictions of our model and a series of historical myths about AP. In each case, the data strongly support our model. We conclude with a general discussion on the nature of AP, the relevance of these findings for other areas of research, and future directions of study. 2005 Elsevier Inc. All rights reserved.
Advantages of motion-JPEG2000 in video processing

The new ISO/ITU-T standard for still image coding, JPEG2000, has been shown to provide superior coding efficiency to the previous standard, JPEG. Because of the superb performance of JPEG2000, it is reasonable to argue that Motion-JPEG2000, the corresponding moving picture coding standard of JPEG2000, has equally outstanding performance. However, there has not been a sufficient performance evaluation of Motion-JPEG2000. To this end, we have studied the potential of Motion-JPEG2000 for video processing. Our experiments show that Motion-JPEG2000 provides high compression performance, strong error resilience, and good perceptual image quality. Together with a rich set of features inherited from JPEG2000, Motion-JPEG2000 has advantages as a coding standard for video processing in many applications.
A very high resolution thermometer for use below 7 K

Abstract We have developed a paramagnetic salt thermometer with a resolution ΔT/T ≈ 3 × 10 −10 at 4 K. We measure the temperature dependent magnetization of a paramagnetic salt in a fixed magnetic field by means of a SQUID magnetometer and a superconducting pick-up circuit. The device shows excellent operating characteristics over a temperature range of from 7 K to 2 K, the maximum that has been used so far. The temperature resolution is within a factor of three of that predicted from detector noise measurements.
p-air cross-section measurement at 1018.5 eV

We present the first measurement of p-air inelastic cross-section at 1018.5 eV using the HiRes stereo fluorescence detector data. A new measurement technique employing de-convolution of the Xmax distribution is proposed. Monte Carlo simulations with the CORSIKA air shower generator and QGSJet and SIBYLL2.1 interaction models are discussed.
KEYNES WITH A PERFECTLY COMPETITIVE GOODS MARKET

A geometric model of an economy with a perfectly competitive goods market based on chapters three and five of Keynes's Genera l Theory is developed. Short-run equilibrium, as well as disequilibri um dynamics, using a market period equilibrium concept, are examined. The model is compared to other Keynesian models; this reveals some p roblems with the fixprice microfoundations approach, and shows how th e diagonal cross and post-Keynesian models, despite some problems, ca n be appropriately reformulated and interpreted. Copyright 1987 by Blackwell Publishers Ltd/University of Adelaide and Flinders University of South Australia
Reversal of aldehyde diastereofacial selectivity in a methyl ketone aldol reaction. Application to the synthesis of the calyculin spiroketal

Abstract It has been observed that aldehyde diastereofacial selectivity in a methyl ketone aldol reaction can be fully regulated under appropriate conditions. Addition of the lithium enolate provided the product derived from apparent chelation control, while Lewis acid-promoted addition of the derived silyl enol ether afforded the Felkin-Anh diastereomer. Application of this methodology to the ongoing synthesis of calysulin A is presented.
APP, Notch, and presenilin: molecular pieces in the puzzle of Alzheimer's disease.

Abstract Deposition of the amyloid-beta protein (Aβ) in the form of cerebral plaques is a defining pathological feature of Alzheimer's disease (AD), and all AD-causing genes identified to date affect Aβ production or deposition. For these reasons, the two proteases, β- and γ-secretases, that cut out Aβ from the amyloid-β precursor protein (APP) are considered important targets for the development of therapeutics for AD. AD-causing mutations in the presenilin genes alter γ-secretase activity, increasing production of the more deleterious 42-residue form of Aβ. Pharmacological profiling, site-directed mutagenesis, knockout studies, affinity labeling, and activity-dependent chromatography all strongly support the hypothesis that presenilin is an integral component of γ-secretase, a founding member of an emerging class of polytopic membrane proteases. γ-Secretase/presenilin also cleaves other proteins that are important for critical signaling events (the Notch family of receptors), raising concerns about mechanism-based toxicities that might arise as a consequence of inhibiting this protease. In light of these findings, the potential of γ-secretase vis-a-vis β-secretase as therapeutic targets for the prevention or treatment of AD will be discussed.
Anti-FcεR1 antibody injections activate basophils and mast cells and delay Type 1 diabetes onset in NOD mice

Mounting evidence suggests that helminth infections protect against autoimmune diseases. As helminths cause chronic IgE-mediated activation of basophils and mast cells we hypothesized that continuous activation of these cells could prevent diabetes onset in nonobese diabetic (NOD) mice in the absence of infection. Anti-FceR1 activated basophils and mast cells and resulted in the release of IL-4 and histamine into the bloodstream. Anti-FceR1-treated NOD mice showed a type 2 shift in insulin-specific antibody production and exhibited significant delays in diabetes onset. IL-4 responses played a partial role as the protective effect of anti-FceR1 therapy was diminished in IL-4-deficient NOD mice. In contrast, histamine signaling was not required as anti-FceR1-mediated protection was not reduced in mice treated with histamine receptor blockers. These results demonstrate that anti-FceR1 therapy delays diabetes onset in NOD mice and suggest that chronic basophil and mast cell activation may represent a new avenue of therapy for Th1-associated autoimmune diseases.
Interstrand cross-linking by bizelesin produces a Watson-Crick to Hoogsteen base-pairing transition region in d(CGTAATTACG)2

1H NMR analysis of the bizelesin adduct of d(CGTAATTACG)2 indicates that adenines six base pairs apart on opposite DNA strands are cross-linked, yielding two major adduct conformations differing in the central duplex region (5'AATT-3'): one (major product) contains an AT step wherein both adenines are syn-oriented and Hoogsteen base paired to thymines (5HG model); the other contains anti-oriented AT-step adenines that show no evidence of hydrogen bonding with pairing thymines (5OP model). The 5OP model consists of three conformers undergoing exchange and differing in the orientation of the AT-step thymines. Bizelesin's size, rigidity, and cross-linking properties restrict the DNA adduct's range of motion and freeze out DNA conformation(s) adopted during the cross-linking process. This most reactive DNA sequence, 5'-TAATTA-3', yields an adduct conformation (5HG) containing a stable region of Watson-Crick (WC) to Hoogsteen (HG) to Watson-Crick base-pairing transitions. While bizelesin exercises a selective effect on DNA conformation, it intrudes into regions of base stacking less than other Hoogsteen pairing-inducing drugs (e.g., echinomycin). Because of this capacity to induce stable Hoogsteen base pairing with only minimal distortion of base-base stacking, bizelesin affords an opportunity to explore this unusual DNA conformation.
High-efficiency photonic crystal narrowband thermal emitters

Photonic crystals (PhC) are artificial structures fabricated with a periodicity in the dielectric function. This periodic electromagnetic potential results in creation of energy bandgaps where photon propagation is prohibited. PhC structures have promising use in thermal applications if optimized to operate at specific thermal emission spectrum. Here, novel utilization of optimized PhC's in thermal applications is presented. We demonstrate through numerical simulation the modification of the thermal emission spectrum by a metallic photonic crystal (PhC) to create high-efficiency multispectral thermal emitters. These emitters funnel radiation from a broad emission spectrum associated with a Plancklike distribution into a prescribed narrow emission band. A detailed quantitative evaluation of the spectral and power efficiencies of a PhC thermal emitter and its portability across infrared (IR) spectral bands are provided. We show an optimized tungsten PhC with a predominant narrow-band emission profile with an emitter efficiency that is more than double that of an ideal blackbody and ~65-75% more power-efficiency across the IR spectrum. We also report on using optimal three-dimensional Lincoln log photonic crystal (LL-PhC) emitters for thermophotovoltaic (TPV) generation as opposed to using a passive filtering approach to truncate the broadband thermal source emission to match the bandgap of a photovoltaic (PV) cell. The emitter performance is optimized for the 1-2μm PV band using different PhC materials, specifically copper, silver and gold. The use of the proposed PhC in TPV devices can produce significant energy savings not reported before. The optimal design of the PhC geometry is obtained by implementing a variety of optimization methods integrated with artificial intelligence (AI) algorithms.
Impact of H+ ion irradiation on Matrimid®. I. Evolution in chemical structure

Ion beam irradiation can be used to modify the structure and gas transport properties of glassy polymers. This is the first of two studies that focus on the impact of H+ ion irradiation on the structure and permeation properties of the polyimide Matrimid®. Specifically, the evolution in chemical structure after H+ irradiation over a range of fluences was analyzed using FTIR spectroscopy and dissolution studies. Although H+ ion irradiation at very low ion fluences induced little modification in the chemical structure, irradiation at relatively high ion fluences resulted in crosslinking of the irradiated films. The branched structure of the aliphatic methyl (CH3) was the most sensitive to the H+ ion irradiation. The para-disubstituted aromatic ring showed the strongest resistance toward ion irradiation and required fairly high doses to induce degradation. Two potential crosslinking mechanisms related to the degradation of the aliphatic methyl and the benzophenone carbonyl were presented. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2010–2019, 2003
Cauchy integrals, Calderón projectors, and Toeplitz operators on uniformly rectifiable domains

Abstract We develop properties of Cauchy integrals associated to a general class of first-order elliptic systems of differential operators D on a bounded, uniformly rectifiable (UR) domain Ω in a Riemannian manifold M. We show that associated to such Cauchy integrals are analogues of Hardy spaces of functions on Ω annihilated by D, and we produce projections, of Calderon type, onto subspaces of L p ( ∂ Ω ) consisting of boundary values of elements of such Hardy spaces. We consider Toeplitz operators associated to such projections and study their index properties. Of particular interest is a “cobordism argument,” which often enables one to identify the index of a Toeplitz operator on a rough UR domain with that of one on a smoothly bounded domain.
Rapid assessment breast clinics – Evolution through audit

This observational, cohort study aimed to examine the potential utility of Rapid Assessment Breast Clinics (RABC) beyond cancer detection at presentation. One thousand four hundred and twenty nine women were studied over an 18 month period. 154 (10.7%) had breast cancer - 87.7% of whom were seen expediently with 92.9% being diagnosed at one attendance. One hundred and forty three (10%) of those with a benign diagnosis were found by routine questioning to have significant familial risk separate to their reason for referral. Despite careful triage, considerable contamination of appointment allotment occurred with many who were correctly triaged as non-urgent being seen 'urgently'. One hundred and seventy six attendees (12.3%) had neither the symptom that triggered referral, nor breast lump, nipple discharge nor family history of breast cancer, while 283 (19.8%) had no objective clinical or radiological abnormality. Although RABC reliably categorise malignant versus non-malignant diagnoses despite cluttering by low risk women, a significant proportion of non-cancer patients still require address of future risk rather than reassurance of their present status alone.
Imaging cardiac extracellular matrices: a blueprint for regeneration

Once damaged, cardiac tissue does not readily repair and is therefore a primary target of regenerative therapies. One regenerative approach is the development of scaffolds that functionally mimic the cardiac extracellular matrix (ECM) to deliver stem cells or cardiac precursor populations to the heart. Technological advances in micro/nanotechnology, stem cell biology, biomaterials and tissue decellularization have propelled this promising approach forward. Surprisingly, technological advances in optical imaging methods have not been fully utilized in the field of cardiac regeneration. Here, we describe and provide examples to demonstrate how advanced imaging techniques could revolutionize how ECM-mimicking cardiac tissues are informed and evaluated.
Anion sensitivity and spectral tuning of cone visual pigments in situ.

Abstract We tested the effect of anions on the absorbance spectrum of native visual pigments as measured by microspectrophotometry in individual cone outer segments of four species of fish and one species of amphibian. In all species tested, the long-wavelength-absorbing cone pigments were anion sensitive, and their lambda max could be tuned over a range of 55 nm depending on the identity of the anion present. Cl- and Br- were the only anions that produced native pigment spectra by red shifting lambda max from its value under anion-free conditions. Lyotropic anions such as NO3-, SCN-, BF4-, and ClO4- caused substantial and graded blue shifts of lambda max. The apparent Kd of binding sites on the pigment for Cl- and for ClO4- was approximately 2 mM. Taken together with previous findings on three visual pigments from the reptilian, avian, and amphibian classes, our results support the hypothesis that all long-wavelength-absorbing vertebrate visual pigments are spectrally tuned in part through the binding of a chloride ion. We propose that the site of anion tuning is near the protonated Schiff base of the chromophore, whose counterion may be complex and include Cl- as an exchangeable anion. This counterion configuration may resemble the one present in the light-driven Cl- pump halorhodopsin.
Finite Element Modeling of Structural Relaxation During Annealing of a Precision-Molded Glass Lens

The precision lens molding process is numerically modeled by incorporating the characteristic structural relaxation phenomenon of glass during the annealing stage. A review of the structural relaxation theory as explained by the Narayanaswamy model (Narayanaswamy, 1971, J. Am. Ceram. Soc., 54(10), pp. 491-498) is provided and is then implemented into the simulation model. The commercial finite element method (FEM) program MSC MARC is utilized for the analysis. Glass material is modeled as a linear Newtonian fluid during the molding stage and as a viscoelastic material exhibiting stress and structural relaxation during the annealing stage. A comparison between the final lens shape and volume results obtained by implementing structural relaxation and thermal expansion coefficient is shown. The results demonstrate the need for including structural relaxation in the simulation model for reliable predictions. The results also show that the FEM can be used to predict the process, improve performance, and also provide a deeper process understanding.
The Dauntless dive bomber of World War Two

From its design and development through the major battles of World War II, this is the story of the dive bomber used by both the U.S. and Japan.
The Impact of Neighborhood Homeownership Rates: A Review of the Theoretical and Empirical Literature

Interest in measuring the impact of neighborhood homeownership rates on the residents of a neighborhood and on surrounding neighborhoods is increasing. This topic is part of the growing literature in the social sciences that discusses the theory and measurement of how neighborhoods affect individuals. In this review, we report on the conceptual categorization of the types of neighborhood effects, we review the social science literature that presents theories of how neighborhoods affect the residents or surrounding areas, and we review the empirical literature that measures the size of neighborhood effects. Throughout, we highlight the impact that differences in neighborhood homeownership rates may have on the economic and social outcomes of the residents. We find numerous theories that, when applied to neighborhood homeownership rates, have rich sets of testable predictions. In contrast, we find few empirical studies of the impact of neighborhood homeownership rates. We conclude that little is known about the impact of cross-sectional or intertemporal variations in neighborhood ownership rates and a substantial amount of additional research is needed. We show that understanding the way in which neighborhood homeownership rates impact behaviors is very important to measuring the impact of public policy. Also, knowing whether neighborhood homeownership effects have a nonlinear impact is important when deciding whether public policy should encourage clusters of homeowners.
Preparation and some properties of the nucleic acid of tobacco streak virus.

Abstract Ribonucleic acid associated with the viral nucleoprotein components characteristic of selected strains of tobacco streak virus was analyzed by density gradient centrifugation and by separation on polyacrylamide gels. In vitro degradation of the RNA extracted was traced to enzymatic action either during virus purification or nucleic acid extraction. When this was minimized, the results still suggested heterogeneity in middle component RNA such that middle and top nucleoprotein components have an RNA species in common. Conceivably the parallel between this property and the common biological properties of these components is significant.
Stem Cells: One step closer to gut repair

The use of adult-tissue stem cells to treat gastrointestinal diseases holds much promise. A method for in vitro growth of gut stem cells and their use in repairing damaged intestines in mice has been described.
Langmuir−Blodgett Films Based on Known Layered Solids: Lanthanide(III) Octadecylphosphonate LB Films

Several lanthanide(III) octadecylphosphonate Langmuir−Blodgett (LB) films have been prepared and characterized. Films with La3+, Ce3+, Sm3+, and Gd3+ are formed one bilayer at a time using a Y-type deposition procedure that allows the metal phosphonate continuous lattice network to crystallize during the upstroke of the film transfer. Comparison of the phosphonate IR stretching modes of the LB films to those of known model solids shows that each film is an LB analogue of the powdered solid-state lanthanide butylphosphonates of formula LnIIIH(O3PC4H9)2 that possess a two-dimensional ionic covalent metal phosphonate network. X-ray photoelectron spectroscopy (XPS) shows that the P/Ln ratio in each of the transferred films is 2:1, which corresponds to the stoichiometry in the known layered materials, and X-ray diffraction (XRD) shows that the films are layered each with a bilayer thickness of 51 ± 1 A. The behavior of octadecylphosphonic acid Langmuir monolayers on subphases containing each metal ion is studi...
Calorimetric study of carbohydrate binding to Concanavalin A

Abstract Flow microcalorimetry has been used to examine the ΔH of binding of two types of saccharides, a series of simple monosaccharides and a series of α-(1 → 4)-linked glucosides, to the lectin Concanavalin A. It has been found that the ΔH decreases with any change in the stereochemistry of a hydroxyl group relative to methyl α- d -mannopyranoside. The data have allowed the calculation of the relative contribution of two of the hydroxyl groups. The ΔH's of binding for the α-(1 → 4)-linked glucosides are approximately 31 kJ/mol, and the apparent association constants vary insignificantly with increasing length. This result indicates that only one glucose residue binds to concanavalin A by hydrogen bonds, and that the additional glucose residues have no interaction either by hydrogen bonds or by nonspecific hydrophobic interactions. This result confirms the absence of an extended binding site for α-(1 → 4)-linked glucopyranosides, in contrast to that proposed for α-(1 → 2)-linked mannopyranosides which show an increase in apparent association constants with increasing length.
Simultaneous excitation of low-frequency cavity modes in short Josephson tunnel junctions

We have studied the simultaneous excitation of the two lowest-frequency cavity modes in a Josephson tunnel junction free from an external magnetic field. Specifically, we have calculated the dc tunneling current contributed by the excitation of these modes when the junction is biased at a voltage $V=nh\frac{{\ensuremath{\nu}}_{c}}{(2e)}$ with $n=1 \mathrm{and} 2$ and ${\ensuremath{\nu}}_{c}$ being the fundamental frequency of the cavity mode. In general, the dc tunneling current depends upon the decay rates of the modes. For $V=2h\frac{{\ensuremath{\nu}}_{c}}{(2e)}$, we found that it can be as large as 0.55 ${I}_{0}(T)$. Here ${I}_{0}(T)$ is the temperature-dependent zero-voltage Josephson critical current of the junction. Furthermore, if the decay rates for the cavity modes are small, multiple solutions for the junction current exist, which implies a fine structure in the current voltage characteristics. For $V=h\frac{{\ensuremath{\nu}}_{c}}{(2e)}$ the dc tunneling current contributed by the cavity modes is zero as long as no magnetic field is applied.
The axoplasmic reticulum within myelinated axons is not transported rapidly

The axoplasmic reticulum in myelinated axons is an extensive system of branched smooth membranous tubules which is found throughout the length of large axons. To investigate its motility and possible role in fast axonal transport, a focal chilling method was used to arrest transport at two sites separated by a 3 mm wide warm region along the saphenous nerve of mice. The experiments ran for 3–4 h since axoplasmic material travelling faster than 25 mm/day would clear from the central warm region. The nerve was subsequently fixed and processed by a technique that enhances the electron density of the axoplasmic reticulum. Thin and thick sections from several regions along the nerve were then systematically studied using conventional and high voltage electron microscopy. In these studies we found that: 1. the axoplasmic reticulum does not accumulate against the proximal sides of the cold blocks; 2. although often closely associated, there is no evidence of continuity between the axoplasmic reticulum and the discrete membranous compartments that do accumulate proximal to the chilled regions; 3. the axoplasmic reticulum remains in the central 3 mm wide warm region; 4. the axoplasmic reticulum does not accumulate against the distal sides of the cold blocks; 5. retrogradely moving elements that do accumulate distal to the cold blocks do not fuse with the axoplasmic reticulum and are not contained in it; and 6. both retrograde and anterograde vector types are often closely associated with elements of axoplasmic reticulum. These results were supported by quantitative morphometric analysis. We conclude that the axoplasmic reticulum represents a discrete membrane system, separate from either anterogradely or retrogradely moving rapid transport vectors, and that this interconnected cisternal system itself is not rapidly transported.
Sensitivity of the fluoride-selective electrode below the micromolar range

Abstract In the presence of fluoride-complexing cations, the lanthanum fluoride electrode responds theoretically to free fluoride one to three decades below lO -6 M , the accepted limit in non-complexing solutions. Experimentally determined fluoride concentrations were compared with values calculated from literature stability quotients for the thorium, zirconium, lanthanum, and hydrogen systems. The limit suggests the presence of background fluoride. Dissolution of the lanthanum fluoride crystal, determined by neutron activation analyses and electrode measurements, could supply the required level of background fluoride in bulk solution. Contribution of fluoride from reagents was not significant.
OPTIMAL SPACING OF PARALLEL BOARDS WITH DISCRETE HEAT SOURCES COOLED BY LAMINAR FORCED CONVECTION

This paper shows numerically how to select the optimal spacing between boards mounted in a stack of specified volume, so that the overall thermal conductance between the stack and the forced coolant is maximum. Several configurations are considered: boards with uniform flux, flush-mounted discrete sources, and protruding heat sources. The flow is laminar and the pressure difference across the stack is fixed (Δp). It is shown that for all the board geometries and thermal boundary conditions studied, the optimal board-to-board spacing is correlated by (Dopt/l ∼ 2.7(Δpl2 / μα)−¼where l is the effective longitudinal (flow) distance occupied by the discrete sources and the unhealed patches contained between them, and μ and α are the viscosity and thermal diffusivity of the fluid. If U∞is the free-stream velocity upstream of the stack, the optimal spacing is given by (Dopt/l) ∼ 3.2pr−¼(U∞l / v)−½.
Prosopagnosia as a Deficit in Encoding Curved Surface

RP is a case of "developmental" prosopagnosia who, according to brain-imaging segmentation data, shows reduction in volume of a limited set of structures of the right hemisphere. RP is as accurate as control subjects in tasks requiring the perception of nonface objects (e.g., matching subordinate labels to exemplars, naming two-tone images), with the exception of one perceptual task: The matching of different perspectives of amoebae-like stimuli (i.e., volumes made of a single smooth surface). In terms of speed ("efficiency") of responses, RP's performance falls clearly outside the normal limits also in other tasks that include "natural" but nonface stimuli (i.e., animals, artia facts). Specifically, RP is slow in perceptual judgments made at very low (subordinate) levels of semantic categorization and for objects and artifacts whose geometry present much curved features and surface information. We conclude from these analyses that prosopagnosia can be the result of a deficit in the representation of basic geometric volumes made of curved surface. In turn, this points to the importance (necessity) for the normal visual system of such curved and volumetric information in the identification of human faces.