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Although recommended lung cancer screening with low-dose computed tomography scanning (LDCT) reduces mortality among high-risk adults, annual screening rates remain low. This study complements a previous nationwide assessment of access to lung cancer screening within 40 miles by evaluating differences in accessibility across rural and urban settings for the population aged 50 to 80 years and a subset eligible population based on the 2021 US Preventive Services Task Force LDCT lung screening recommendations.Distances from population centers to screening facilities (American College of Radiology Lung Cancer Screening Registry) were calculated, and the number of individuals who had access within graduating distances, including 10, 20, 40, 50, and 100 miles, were estimated. Census tract results were aggregated to counties, and both geographies were classified with rural-urban schemas.Approximately 5% of the eligible population did not have access to lung cancer screening facilities within 40 miles; however, different patterns of accessibility were observed at different distances, between regions, and across rural-urban environments. Across all distances and geographies, there was a larger percentage of the population in rural geographies with no access. Although the rural population represented approximately 8% of the eligible population, the larger percentage of the rural population with no access was noteworthy and translated into a larger number of individuals with no access at longer distance thresholds (≥40 miles).Disparities in access should be examined as both percentages of the population and numbers of individuals with no access in order to tailor interventions to communities and increase access. Geospatial analysis at the census tract level is recommended to help to identify optimal focus areas and reach the most people.As annual lung cancer screening rates remain low, this study examines access to lung cancer screening nationwide and across rural and urban settings. A geographic information system network analysis of census tract-level populations is used to estimate access at different distances, including 10, 20, 40, 50, and 100 miles, and the results are aggregated to counties. Approximately 5% of the eligible population does not have access to screening facilities within 40 miles; however, different patterns of accessibility are observed at different distances, between regions, and across rural-urban environments. Across all distances and geographies, there is a larger percentage of the population in rural geographies with no access.

Background Screening current and former heavy smokers 55 to 80 years of age for lung cancer (LC) with low-dose chest CT scanning has been recommended by the United States Preventive Services Task Force since 2013. Although the number of screening facilities in the United States has increased, screening uptake has been slow. Research Question To what extent is geographic access to screening facilities a barrier for screening uptake nationally? Study Design and Methods Screening facilities were defined as American College of Radiology (ACR) Lung Cancer Screening Registry (LCSR) facilities. Analysis was performed at different geographic levels using a road network to calculate travel distances for the recommended age groups. Full access to screening was defined as the entire 55- to 79-year-old population being within 40 miles of an ACR LCSR facility. No access was defined as lack of access by the entire target population. Partial access was expressed in intervening quartiles. A geospatial approach then was used to integrate accessibility with smoking prevalence and LC mortality rates to identify potential focus areas visually. Results Screening facilities addresses were geocoded to identify 3,592 unique locations. Analysis of census tracts and aggregation to counties revealed that among 3,142 counties, adults 55 to 79 years of age have full access to an LC screening registry facility in 1,988 (63%) counties, partial access in 587 (19%) counties, and no access in 567 (18%) counties. Overall, less than 6% of those 55 to 79 years of age do not have access to registry screening facilities. Variation in screening facility access was noted across the United States, between states, and within some states. Interpretation It is recommended to calculate accessibility using subcounty geographies and to examine variation regionally and within states. A foundation geographic accessibility layer can be integrated with other variables to identify geographic disparities in access to screening and to focus on areas for interventions. Identifying areas of greatest need can inform state and local officials and healthcare organizations when planning and implementing LC screening programs.

We construct four different real representations of the minimal vector clover extension and their covariant derivatives. We determine their relation to the basic representation and initiate the exploration of constrained superfields.

We construct a differential representation and covariant derivatives of the minimal vector clover extension of the Poincare algebra. In analogous way as in the supersymmetric case, there arises an enhanced superspace which allows to define superfields. The action of group transformations on such superfields determines a representation out of which the covariant derivatives are obtained.

During interphase, chromatin hosts fundamental cellular processes, such as gene expression, DNA replication and DNA damage repair. To analyze chromatin on a proteomic scale, we have developed chromatin enrichment for proteomics (ChEP), which is a simple biochemical procedure that enriches interphase chromatin in all its complexity. It enables researchers to take a 'snapshot' of chromatin and to isolate and identify even transiently bound factors. In ChEP, cells are fixed with formaldehyde; subsequently, DNA together with all cross-linked proteins is isolated by centrifugation under denaturing conditions. This approach enables the analysis of global chromatin composition and its changes, which is in contrast with existing chromatin enrichment procedures, which either focus on specific chromatin loci (e.g., affinity purification) or are limited in specificity, such as the analysis of the chromatin pellet (i.e., analysis of all insoluble nuclear material). ChEP takes half a day to complete and requires no specialized laboratory skills or equipment. ChEP enables the characterization of chromatin response to drug treatment or physiological processes. Beyond proteomics, ChEP may preclear chromatin for chromatin immunoprecipitation (ChIP) analyses.

We aim to approach a trefoil symmetry involving (Z4×Z4;q)-graded parameters, multiplets of generators of integer spin

A graded minimal Lie algebraic extension of the space–time symmetry is constructed involving only spin-1 multiplets as novel generators. The extension involves Z4×Z4 graded parameters and generators. It provides a bosonic analog to supersymmetry since the composition of three symmetric vector charges produces a space–time translation. There arise three noncommutative four-dimensional manifolds with pseudometric.

We construct a novel graded extension of the Poincare group with integer spin multiplets as novel generators. The extension involves Z4×Z4 graded parameters and produce space–time translations through the composition of novel symmetric vector and scalar multiplets.

Ba1-x SrxTiO3 (BST) thin films were deposited by reactive rf-magnetron sputtering onto Si substrates. The influence of the deposition parameters such as temperature and oxygen ambient on the dielectric constant of the films is presented. BST films deposited at 450°C and optimum conditions exhibited a dielectric constant of approximately 200 at frequencies as high as 1GHz. In addition, the films were found to have leakage current densities of

Ferroelectric thin films as the recording media of scanning probe microscope-based storage devices were investigated using an atomic force microscope(AFM) technique. Polarization domains were formed in the PbZrxTi1-xO3(PZT) thin films epitaxialy grown on the epitaxial SrRuO3(SRO) thin films on SrTiO3 substrate by applying a pulse voltage between the conductive tip of AFM and SRO as a bottom electrode. The polarized domains were observed by detecting the inverse-piezoelectricity-induced surface vibration of the PZT thin film caused by applying an ac modulation voltage to the conductive tip. The recording density of polarized domains, domain switching speed and preliminary retention characteristics of polarized domains were studied. The polarized domains as small as 30 nm are formed in the PZT thin film with the thickness of 45 nm. The small domains can be formed by applying a 100 ns pulse of 10 V to the conductive tip. As for the retention characteristics of polarized domains with a size of 90–110...

Single-crystal thin films of Pb(ZrxTi1−x)O3 (PZT) covering the full compositional range (0⩽x⩽1) were deposited by metal-organic chemical vapor deposition. Epitaxial SrRuO3(001) thin films grown on SrTiO3(001) substrates by rf-magnetron sputter deposition served as template electrode layers to promote the epitaxial growth of PZT. X-ray diffraction, energy-dispersive x-ray spectroscopy, atomic force microscopy, transmission electron microscopy, and optical waveguiding were used to characterize the crystalline structure, composition, surface morphology, microstructure, refractive index, and film thickness of the deposited films. The PZT films were single crystalline for all compositions exhibiting cube-on-cube growth epitaxy with the substrate and showed very high degrees of crystallinity and orientation. The films exhibited typical root mean square surface roughness of ∼1.0–2.5 nm. For tetragonal films, the surface morphology was dominated by grain tilting resulting from ferroelectric domain formation. We r...

We have characterized the dielectric properties of barium strontium titanate (Ba1-xSrxTiO3, x=0.5; BST) capacitors up to 5 GHz employing a simple, single port scattering parameter measurement technique. Metal-insulator-metal type capacitors with areas ranging from 400 to 10,000 μm2 were defined by standard photolithographic and etching techniques. BST films were rf-magnetron sputter-deposited on metallized (111) silicon. The bottom electrode was made by evaporating 100A of Ti for adhesion followed by 1500A of Pt. The top electrode consisted of 3000A of gold with a 100A titanium adhesion layer. The test capacitors were surrounded by a reference capacitor approximately 140 times in area to facilitate high frequency measurements with air coplanar (ACP) probes. The test and the reference capacitors were in series during characterization ensuring that the resulting capacitance was dominated by the smaller test structure. Single port scattering parameters (S11) were obtained using a HP8510B network ana...

Measurements of the temperature dependent transport properties of epitaxial BaTiO3 are reported. Electrical resistivity and thermoelectric power were measured over the temperature range of 77–300 K. Room temperature resistivities of the as‐deposited, undoped films range from 105 to 108 Ω cm, while values as low as 55 Ω cm are obtained for the La‐doped films. The resistivity shows an activated temperature dependence with the measured activation energies ranging between 0.11 and 0.50 eV. The activation energy depends strongly upon the thin film carrier concentration. Thermoelectric power measurements indicate that the films are n‐type. The Seebeck coefficient for La‐doped BaTiO3 exhibits metallike behavior, with its magnitude directly proportional to temperature. Temperature dependent resistivity and thermopower measurements indicate that the carrier mobility is activated. A transport model is proposed whereby conduction occurs in the La‐doped films via hopping between localized states within a pseudogap fo...

Epitaxial SrRuO3 thin films were deposited on SrTiO3 (100) substrates by RF sputtering for use as bottom electrodes and epitaxial buffer layers. On these conductive substrates, epitaxial Pb(Zr0.35Ti0.65)O3 (PZT) thin films were deposited by metalorganic chemical vapor deposition (MOCVD). X-ray diffraction (XRD), transmission electron microscopy (TEM) and optical waveguiding were used to characterize the phase, refractive index, and film thickness of the deposited films. The epitaxial PZT films were c-axis oriented and contained -19.7% volume fraction of 90° domains. Ferroelectric hysteresis and dielectric measurements of epitaxial PZT ferroelectric capacitor structures formed using sputtered ITO top electrodes showed: a remanent polarization of 51.8 Ω/cm2, a coercive field of 54.9 kV/cm, a dielectric constant of 410, a bipolar resistivity of ∼5.8x109 Ω-cm at a field of 275 kV/cm, and a breakdown strength of >400 kV/cm. The cyclic fatigue behavior of the films showed a strong dependenc...

Second harmonic generation from a 1.064 μm fundamental was measured on BaTiO 3 thin films derived from metalorganic chemical vapor deposition. Significant enhancement of the second harmonic generation was observed upon poling of the film using corona discharge. The second harmonic intensity of the poled film was studied as a function of the incident fundamental polarization, showing that there was no in-plane symmetry in the poled films. The measured macroscopic second-order nonlinear optical coefficient of the poled film, d film 33 , is ∼ 7.5 pm/V. This value is comparable to that of the bulk BaTiO 3 along c -axis, d BaTiO 3 33 , suggesting that the majority of the crystalline c -axis of the poled film was aligned to the film normal.

The measured switched polarization properties of integrated Pb(Zr,Ti)O3 (PZT) capacitors arrays have been found to show a small dependence on individual capacitor size in the range from 0.17 and 100 μm2. These thin (90 nm) PZT capacitors have low voltage switching properties with polarization saturation of

Low pressure organometallic chemical vapor deposition was used to prepare ferroelectric thin films. Both the bismuth and the strontium titanate system were investigated. Under the optimal growth conditions phase pure, textured films could be prepared. The growth parameters which influenced composition and phase stability were examined.

We have observed nonorthogonal twinning in thin film oxide perovskites. This twinning geometry is equivalent to a 60° rotation of the twinned crystallites about the [111] direction in an [001] oriented film. This twinning is not detectable by the standard x‐ray tests for film quality (a radial θ–2θ scan and a φ scan at a chi of 45°). In this study we observe this twinning in films of PbZrxTi1−xO3, BaTiO3, and SrRuO3 grown by sputtering and MOCVD on MgO and SrTiO3. These twins are observed in films deposited on a substrate with which there is a large lattice mismatch and in films that are deposited in an oxygen deficient environment. We propose that these twins result from plastic deformation associated with misfit accommodation and discuss the twin geometry and the nature of the twin interface.

Summary form only given. High-density, embedded ferroelectric memory (FeRAM) has the potential to replace embedded flash, embedded DRAM, and non-cache SRAM and could be a key enabler for future system-on-a-chip applications. Despite this appeal, the evidence that ferroelectric capacitors can be scaled to the submicron regime has been limited. In this paper, we report the fabrication and electrical properties of submicron PZT capacitors formed using both planar bottom electrodes and W plug contact structures. We observe that the aggregate saturation polarization value is nearly independent of individual capacitor area in the measured range from the contact-limited size of 0.12 /spl mu/m/sup 2/ to 10/sup 4/ /spl mu/m/sup 2/. This result suggests that high-density, embedded FeRAM technology may be feasible.

Dielectric and ferroelectric properties were measured for both highly a‐axis textured and randomly oriented BaTiO3 thin films deposited on Pt coated MgO substrates via metal‐organic chemical‐vapor deposition. Dielectric constants on the order of e∼10 and an absence of ferroelectric hysteresis were generally observed for the as‐deposited films. Upon applying an electric field exceeding a threshold value of ∼50–100 kV/cm across the film, both the dielectric constant and the ferroelectric hystersis were enhanced significantly as a result of poling. The dielectric constant increased to e∼100, and the spontaneous polarization of the a‐axis textured film reached Ps≥15 μC/cm2. The measured dielectric and ferroelectric properties of the BaTiO3 thin films depended on the microstructure of the films.

The effect of electron beam irradiation on second harmonic generation of BaTiO3 thin films was studied. Enhanced second harmonic intensity was measured from BaTiO3 thin films irradiated by electron beams of 10, 15, and 25 keV using a scanning electron microscope. The enhancement of the second harmonic generations is attributed to the electron beam‐induced poling of the film. The effectiveness of the electron beam irradiation on second harmonic generation enhancement is comparable to that of the corona poling of the film at room temperature. This electron beam induced poling technique offers a promising method for nonlinear optical device fabrication.

BaTiO3 thin films grown on LaA1O3 by organometallic chemical vapor deposition were characterized with cross-sectional high resolution transmission electron microscopy. Epitaxy was confirmed for the films grown on (100) oriented substrates. The films displayed an aaxis orientation. The interface between the film and substrate was nearly atomically abrupt. Partial relaxation of the films was observed as a result of misfit dislocation formation.

Second‐harmonic generation of 1.064 μm incident light was measured on BaTiO3 thin films prepared by metalorganic chemical vapor deposition. Upon corona poling of the film, the second‐harmonic signal was significantly enhanced. The second‐order nonlinear optical susceptibility, d, of the poled film reaches ∼7.5 times that of the quartz. The enhanced second‐harmonic generation shows a very slow decay at room temperature.

Epitaxial BaTiO3 thin films were grown in situ on (100) LaAlO3 by low‐pressure organometallic chemical vapor deposition using the precursors Ba (hexafluoroacetylacetonate)2 (tetraglyme) and titanium tetraisopropoxide. The phase composition and epitaxial quality were sensitive to the reactant partial pressures and growth temperature. Deposition at 800 °C yielded [100]‐oriented BaTiO3 films. In‐plane epitaxy was confirmed for the BaTiO3 films by x‐ray diffraction.

Isolated primary non-Hodgkin's lymphoma of the frontal sinus is rare. We describe the case of a middle-aged man who came to us with signs of orbital cellulitis complicating an acute infected frontal mucocele. His condition was initially controlled with medical therapy and subsequent endoscopic sinus surgery, but his symptoms eventually returned. We were able to diagnose the lymphoma only by approaching the sinus externally to obtain a biopsy. This case highlights the importance of making a full visual inspection of the involved sinus in order to avoid missing an unexpected, albeit a rarely encountered, pathology.

Epitaxial SrRuO3 thin films were deposited on SrTiO3(100) and MgO(100) substrates by rf sputtering for use as bottom electrodes and epitaxial buffer layers. On these conductive substrates, epitaxial Pb(ZrxTi1-x)O3 (PZT; x equals 0.35, 0.65) and PbTiO3 (PT; x equals 0) thin films were deposited by metalorganic chemical vapor deposition (MOCVD). X-ray diffraction (XRD), RBS channeling (RBS), transmission electron microscopy (TEM) and optical waveguiding were used to characterize the phase, microstructure, defect structure, refractive index, and film thickness of the deposited films. The PZT and PT films were epitaxial and c-axis oriented. Ninety degree domains, interfacial misfit dislocations and threading dislocations were the primary structural defects, and the films showed as high as 70% RBS channeling reduction. Ferroelectric hysteresis and dielectric measurements of epitaxial PZT ferroelectric capacitor structures formed using evaporated Ag top electrode showed: a remanent polarization of 46.2 (mu) C/cm2, a coercive field of 54.9 kV/cm, a dielectric constant of 410, a bipolar resistivity of approximately 5.8 X 109 (Omega) -cm at a field of 275 kV/cm, and a breakdown strength of > 400 kV/cm. Cyclic fatigue measurements showed that the remanent polarization was maintained for > 109 cycles.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Epitaxial SrRuO{sub 3} thin films were deposited on SrTiO{sub 3}(100) and MgO(100) substrates by RF sputtering for use as bottom electrodes and epitaxial buffer layers. On these conductive substrates, epitaxial Pb(Zr{sub x}Ti{sub 1{minus}x})O{sub 3} (PZT; x = 0.35,0.65) and PbTiO{sub 3} (PT; x = 0) thin films were deposited by metalorganic chemical vapor deposition (MOCVD). X-ray diffraction (XRD), RBS channeling (RBS), transmission electron microscopy (TEM) and optical waveguiding were used to characterize the phase, microstructure, defect structure, refractive index, and film thickness of the deposited films. The PZT and PT films were epitaxial and c-axis oriented. 90{degree} domains, interfacial misfit dislocations and threading dislocations were the primary structural defects, and the films showed as high as a 70% RBS channeling reduction. Ferroelectric hysteresis and dielectric measurements of epitaxial PZT ferroelectric capacitor structures formed using evaporated Ag top electrode showed: a remanent polarization of 46.2 {mu}C/cm{sup 2}, a coercive field of 54.9 kV/cm, a dielectric constant of 410, a bipolar resistivity of {approximately}5.8 {times} 10{sup 9} {Omega}-cm at a field of 275 kV/cm, and a breakdown strength of >400 kV/cm. Cyclic fatigue measurements showed that the remanent polarization was maintained for >10{sup 9} cycles.

Single-crystal thin films covering the full compositional range of Pb(ZrxTi1−x)O3(PZT) 0≤x≤1 have been deposited by metal-organic chemical vapor deposition (MOCVD). The films were grown on epitaxial, RF-sputter-deposited SrRuO3 thin film electrodes on (001) SrTiO3 substrates. X-ray diffraction (XRD), energy-dispersive electron spectroscopy (EDS) and optical waveguiding were used to characterize the crystalline structure, composition, refractive index, and film thickness of the deposited films. We found that the PZT films were single-crystalline for all compositions exhibiting cube-on-cube epitaxy with the substrate with very high degrees of crystallinity and orientation. We report the systematic variations in the optical, dielectric, polarization, and transport properties as a function of composition and the epitaxy-induced modifications in the solid-solution phase diagram of this system. These films exhibited electronic properties which showed clear systematic variations with composition. High values of remnant polarization (30–55 μC/cm2) were observed at all ferroelectric compositions. Unlike previous studies, the dielectric constant exhibited a clear dependence on composition with values ranging from 225–650. The coercive fields decreased with increasing Zr concentration to a minimum of 20 kV/cm at the (70/30) composition. In addition, these films exhibited both high resistivity and dielectric-breakdown strength (˜1013 Ω-cm at 100 kV/cm and >300 kV/cm, respectively) without any compensative doping.

Epitaxial BaTiO3/SrRuO3 heterostructures were deposited on MgO and SrTiO3 substrates by 90° off-axis, rf-magnetron sputtering. A template layer growth was required to obtain epitaxy on MgO. The crystalline structure of the films was analyzed with x-ray diffraction. The leakage current and remanent polarization depended on the crystalline structure and processing parameters. The BaTiO3 thin films displayed remanent polarizations of 13 μC/cm2 and leakage current densities of 107 Amps/cm2 at 2 volts. The BaTiO3 thin films grown under optimal conditions displayed very little fatigue up to 5×108 cycles.

Epitaxial SrRuO3 thin films were deposited by RF sputtering on SrTiO3 or MgO substrates for use as underlying electrodes. On these conductive substrates, epitaxial Pb(Zr0.35Ti0.65)O3 (PZT) and PbTiO3 (PT) thin films were deposited by metalorganic chemical vapor deposition (MOCVD). X-ray diffraction (XRD), RBS channeling (RBS), transmission electron microscopy (TEM) and optical waveguiding were used to characterize the phase, microstructure, defect structure, refractive index, and film thickness of the deposited films. The PZT and PT films were epitaxial and c-axis oriented. 90° domains, interfacial misfit dislocations and threading dislocations were the primary structural defects, and the films showed a 70% RBS channelling reduction. Hysteresis and dielectric measurements of epitaxial PZT ferroelectric capacitor structures formed using evaporated Ag or ITO glass top electrode showed: a remanent polarization of 46.2 μC/cm2 a coercive field of 54.9 kV/cm, a dielectric constant of 410, a bipolar resistivity of ∼5.8×109 ω-cm at a field of 275 kV/cm, and a breakdown strength of >400 kV/cm.

We have examined the incidence of Harvey ras mutations in human squamous cell carcinomas (SCC) of the upper aerodigestive tract using the polymerase chain reaction (PCR) followed by direct sequencing. No mutations were detected at codons 12, 13, 59 or 61 of this gene in any of six papillomas, five erythroplakias, 56 squamous cell carcinomas, and 16 SCC cell lines. Some of the SCC were lymph node metastases (three) or tumours which had recurred following radiotherapy (seven). We conclude that Harvey ras mutations are not a common event in the pathogenesis or recurrence of SCCs from Caucasian subjects, in contrast to the situation with Indian populations (Saranath et al., 1991). Images Figure 1

Ferroelectric and dielectric properties were measured for BaTiO3 thin films prepared by metalorganic chemical vapor deposition which were highly a-axis textured. No ferroelectric hysteresis was observed from the as-deposited BaTiO3 films on Pt coated MgO. Upon applying an electric field exceeding a threshold electric field, Et, ∼ 50 - 100 kV/cm, a ferroelectric hysteresis was observed. A spontaneous polarization Ps ≥ 15 μC/cm2 was measured for the textured films.

The defect structure of BaTiO3 thin films grown on (100) Si was examined using transient photocapacitance spectroscopy. The concentration, optical cross section and associated energy levels of both native and impurity defects in as-grown and annealed BaTiO3 films were evaluated. Deep level defects withpeak energies of Ev+1.8, Ev+2.4, Ev+2.7, Ev+3.0-3.1 and Ev+3.2-3.3 eV were observed in the as-grown films. Upon vacuum annealing, the concentration of the traps at Ev+3.0 and Ev+3.2 eV increased while the concentration of the traps at Ev+ 1.8 and Ev+2.4 eV decreased. The levels at Ev+3.0-3.1 and Ev+3.2-3.3 eV are attributed to oxygen vacancies. The other levels are tentatively ascribed to Fe and Fe related defects.

We study graded Lie algebras whose transformation parameters are graded q -commutativive and r -associative. We study first some graded algebras over a field, with no zero divisors at the level of monomials in their graded algebra generators. These generators are q -commutative and r -associative. We address the cohomology of the q -function and r -functions, in particular we study quaternions and octonions. We then define algebras whose transformation parameters are q -commutative and r -associative. We address a generalization of a theorem by Scheunert on its relation to Lie (super)algebras. We show finally that for the cases studied by Scheunert there is always a real and faithful transformation parameter basis with the required q -commutativity. We use this basis to perform a transformation on the graded Lie algebra that relates it to a plain Lie (super)algebra while respecting the self-adjoint character of generators and preserving the group grading. Keywords: Graded Lie (super)algebras, Color Lie (super)algebras, noncommutative algebras, nonassociative algebras, cohomology of deformation parameters, perfect algebra. AMS-MSC: 17B70, 17B75, 22E60, 17A99, 17D99, 13D03, 20J06.

BaTiO3 thin films have been prepared by low pressure organometallic chemical vapor deposition on (100) MgO and (100) LaAlO3 substrates using the volatile precursors, titanium(IV) tetraisopropoxide and barium (hexafluoroacetylacetonate)2 (tetraglyme). The phase composition and structure of the films depends on the reactant partial pressure, growth temperature, and substrate. High quality, epitaxial BaTiO3 films can be prepared in-situ on LaAlO3 as confirmed by x-ray diffraction measurements. These BaTiO3 films exhibit smooth surface morphologies as evidenced by scanning electron microscopy. Electrical resistivity measurements indicate that the films are semi-insulating.

A field study on two caged layer poultry operations assessed whether selected pesticides would affect beneficial predators. Sampling was done three times during the 5-wk period before treatment, 3 d after each of two weekly treatments, and 5-6 times during the 10 wk after the second treatment. Cyromazine (0.1%) applied topically had no detrimental effect on any of the predator taxa. Dimethoate (0.5%) applied as a spot treatment to wet areas of the manure also did not reduce predator abundance. Permethrin (0.05%) applied as a direct treatment to the hens resulted in slight reductions in numbers of Histeridae and Staphylinidae in the manure. A resurgence of Fanniinae occurred at one site 3 wk after permethrin application. Treatment of whole houses with dimethoate (0.5%) resulted in short-term reductions (up to 3 wk) of predatory mites and reductions of Histeridae and Staphylinidae for 4-10 wk.

Nanometer size polarized domains were written in a PbZr1−xTixO3 (PZT) thin film using an atomic force microscope (AFM) and the relationship between the polarized domain and the grain of the film was investigated. The polarized domain was formed by applying a pulse voltage to the ferroelectric PZT thin film through a conductive AFM tip. The polarized domain structure was observed by imaging the piezoelectric‐induced surface vibration by an AFM with an ac voltage applied between the tip and the bottom electrode of a sample. The polarized domains with a diameter of 50 nm were written within a single grain.

A prospective survey of 738 children with high risk factors was carried out in the north-east of Scotland. High risk factors used in previous surveys were reviewed and considered inadequate. New and stringent standards are described. Results are compared with the national incidence of sensori-neural deafness and with other surveys.

The counties of Warwick and Worcester have yielded the majority of Keuper fossils recorded from England. The history of their discovery commenced about seventy years ago with a paper by Murchison and Strickland, where there is a description of the area. They distinguished two divisions, the lower of which they identified as Bunter, chiefly on the evidence of a plant, Echinostdchys oblovgus, Brongn. This division was found to be, for the most part, composed of sandstones, and contained in Worcestershire plant remains and in Warwickshire bones and teeth. The localities where fossils were found were Ombersley, Hadley, Elmley Lovett, all on the west side of the Droitwich basin, Bromsgrove on the east of it, and in the Warwick district.

IN the course of the Leicester meeting of the British Association in 1933, Section C visited the Nuneaton district and saw, amongst other exposures, sections showing the junction of the Cambrian and Pre-Cambrian. Two of these have never been previously described, and the most striking one (that in the north corner of Messrs. Boon’s quarry) was only first seen by the writers when on a preliminary tour of the excursion route. Both sections merit description, in view of the light which they throw upon the nature of the unconformable junction of the two systems, and upon the character of the Pre-Cambrian rocks and their relation to the rocks of Charnwood Forest.

A new circuit is introduced to generate the logarithmic time base function with good resolution. By using a single‐chip microcomputer with EPROM program storage, the circuitry is simplified and can be easily reproduced. The output function covers more than six decades of time and has 590 discrete points per decade with an accuracy of one discrete point per decade or ±0.16%. The design overcomes two well‐known problems in using the logarithmic time base. First because the time increments are derived from a real‐time register there is a precise reference for zero time, and second a series of time base interval marks are output for correctly calibrating the time axis.