55,963 research outputs found
The use of photographic methods in contrast enhancement of ERTS-1 images
The contrast of ERTS 70mm positive images can be enhanced to varying degrees by rephotographing the images with different types of negative films, and by overdeveloping the films with different developers. A combination of high contrast copy film (Kodak 5069) and a high energy developer (Kodak D-11) yields high contrast. Still greater contrast may be otbained by using a film of higher contrast capability and a developer of higher energy capability. Contrast can also be enhanced in the printing process with the use of highcontrast photographic papers, or with the use of polycontrast photographic paper and filters. Contrast enhancement by photocopying delineates topographic boundaries and may aid in the objective measurement of topographic parameters
Recurrence Formulas for Fully Exponentially Correlated Four-Body Wavefunctions
Formulas are presented for the recursive generation of four-body integrals in
which the integrand consists of arbitrary integer powers (>= -1) of all the
interparticle distances r_ij, multiplied by an exponential containing an
arbitrary linear combination of all the r_ij. These integrals are
generalizations of those encountered using Hylleraas basis functions, and
include all that are needed to make energy computations on the Li atom and
other four-body systems with a fully exponentially correlated Slater-type basis
of arbitrary quantum numbers. The only quantities needed to start the recursion
are the basic four-body integral first evaluated by Fromm and Hill, plus some
easily evaluated three-body "boundary" integrals. The computational labor in
constructing integral sets for practical computations is less than when the
integrals are generated using explicit formulas obtained by differentiating the
basic integral with respect to its parameters. Computations are facilitated by
using a symbolic algebra program (MAPLE) to compute array index pointers and
present syntactically correct FORTRAN source code as output; in this way it is
possible to obtain error-free high-speed evaluations with minimal effort. The
work can be checked by verifying sum rules the integrals must satisfy.Comment: 10 pages, no figures, accepted by Phys. Rev. A (January 2009
Web 2.0 and micro-businesses: An exploratory investigation
This is the author's final version of the article. This article is (c) Emerald Group Publishing and permission has been granted for this version to appear here. Emerald does not grant permission for this article to be further copied/distributed or hosted elsewhere without the express permission from Emerald Group Publishing Limited.This article was chosen as a Highly Commended Award Winner at the Emerald Literati Network Awards for Excellence 2013.Purpose â The paper aims to report on an exploratory study into how small businesses use Web 2.0 information and communication technologies (ICT) to work collaboratively with other small businesses. The study had two aims: to investigate the benefits available from the use of Web 2.0 in small business collaborations, and to characterize the different types of such online collaborations.
Design/methodology/approach â The research uses a qualitative case study methodology based on semi-structured interviews with the owner-managers of 12 UK-based small companies in the business services sector who are early adopters of Web 2.0 technologies.
Findings â Benefits from the use of Web 2.0 are categorized as lifestyle benefits, internal operational efficiency, enhanced capability, external communications and enhanced service offerings. A 2Ă2 framework is developed to categorize small business collaborations using the dimensions of the basis for inter-organizational collaboration (control vs cooperation) and the level of Web 2.0 ICT use (simple vs sophisticated).
Research limitations/implications â A small number of firms of similar size, sector and location were studied, which limits generalizability. Nonetheless, the results offer a pointer to the likely future use of Web 2.0 tools by other small businesses.
Practical implications â The research provides evidence of the attraction and potential of Web 2.0 for collaborations between small businesses.
Originality/value â The paper is one of the first to report on use of Web 2.0 ICT in collaborative working between small businesses. It will be of interest to those seeking a better understanding of the potential of Web 2.0 in the small business community.WestFocu
The photons payload, G-494: A learning experience
PHOTONS (Photometric Thermospheric Oxygen Nightglow Study) is an optical remote sensing payload developed for Get Away Special (GAS) flight by the National Research Council of Canada. The device is extremely sensitive and is suitable for making measurements of low intensity, aeronomically generated atmospheric emissions in the nadir and the limb and of Shuttle ram glow. The unit uses a sealed canister and UV transmitting viewing ports. During the flight of STS 61-C, PHOTONS received one hour of operation and aeronomic observations were made. Good diagnostic data were obtained and the science part of the experiment malfunctioned. Post flight inspection revealed that the payload was in perfect working order except for total failure of the photomultiplier detectors. The experiment and the payload are described and the flight results are discussed along with the cause of the malfunctions. It is shown that enough was learned from the flight diagnostic data and about the cause of the malfunction to conclude that the engineering flight was successful and that subsequent flight of the PHOTONS payload will be productive
Recent Developments in Osteogenesis Imperfecta
Osteogenesis imperfecta (OI) is an uncommon genetic bone disease associated with brittle bones and fractures in children and adults. Although OI is most commonly associated with mutations of the genes for type I collagen, many other genes (some associated with type I collagen processing) have now been identified. The genetics of OI and advances in our understanding of the biomechanical properties of OI bone are reviewed in this article. Treatment includes physiotherapy, fall prevention, and sometimes orthopedic procedures. In this brief review, we will also discuss current understanding of pharmacologic therapies for treatment of OI
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Novel tretinoin 0.05% lotion for the once-daily treatment of moderate-to-severe acne vulgaris in a preadolescent population.
BackgroundAcne vulgaris (acne) is a common skin condition in children and adolescents. Efficacy of tretinoin is well documented in studies that included pediatric patients (12-18 years of age). With acne routinely presenting in younger patients, data are needed in this important group. Lotion formulations are commonly used across dermatology and are well liked by patients.ObjectiveTo evaluate the safety and efficacy of a novel once-daily tretinoin 0.05% lotion in preadolescent subjects (â€Â 13 years) with moderate-to-severe acne.MethodsPost hoc analysis of two multicenter, randomized, double-blind, vehicle-controlled phase 3 studies in moderate-to-severe acne. Preadolescent subjects (N = 154) randomized (1:1) to receive tretinoin 0.05% lotion or vehicle, once daily for 12 weeks. Efficacy assessments included changes in baseline inflammatory/noninflammatory lesions and treatment success (at least 2-grade reduction in Evaluator's Global Severity Score [EGSS] and clear/almost clear). Safety, adverse events (AEs), and cutaneous tolerability evaluated throughout.ResultsAt Week 12, mean percent reduction in inflammatory and noninflammatory lesion counts were 49.5% and 44.0% compared with 31.4% and 18.8% with vehicle (both P = 0.001). Treatment success was achieved by 23.7% of subjects by Week 12, compared with 7.2% (P = 0.009). The majority of AEs were mild and transient: most frequently were application site pain (5.6%) and application site dryness (2.8%). Local cutaneous safety and tolerability assessments were generally mild-to-moderate and improved by Week 12.ConclusionsTretinoin 0.05% lotion was significantly more effective than vehicle in achieving treatment success and reducing inflammatory and noninflammatory lesions in preadolescent acne. It was well tolerated, with all treatment-related AEs deemed mild or moderate
Creep Evaluation of (Orthotic) Cast Materials During Simulated Clubfoot Correction
The Ponseti method is a widely accepted and highly successful conservative treatment of pediatric clubfoot that relies on weekly manipulations and cast applications. However, the material behavior of the cast in the Ponseti technique has not been investigated. The current study sought to characterize the ability of two standard casting materials to maintain the Ponseti corrected foot position by evaluating creep response. A dynamic cast testing device (DCTD) was built to simulate a typical pediatric clubfoot. Semi-rigid fiberglass and rigid fiberglass casting materials were applied to the device, and the rotational creep was measured at various constant torques. The movement was measured using a 3D motion capture system. A 2-way ANOVA was performed on the creep displacement data at a significance level of 0.05. Among cast materials, the rotational creep displacement was found to be significantly different (p-values âȘ 0.001). The most creep displacement occurs in the semi-rigid fiberglass (approximately 1.0 degrees), then the rigid fiberglass (approximately 0.4 degrees). There was no effect of torque magnitude on the creep displacement. All materials maintained the corrected position with minimal change in position over time
Sagittal Subtalar and Talocrural Joint Assessment With Weight-Bearing Fluoroscopy During Barefoot Ambulation
Background: Identifying talar position during ambulation has proved difficult as the talus lacks palpable landmarks for skin marker placement and more invasive methodologies such as bone pins are not practical for most clinical subjects. A fluoroscopic motion system was used to track the talus and calcaneus, allowing kinematic analysis of the talocrural and subtalar joints. Methods: Thirteen male subjects (mean age 22.9 ± 3.0 years) previously screened for normal gait were tested. A fluoroscopy unit was used to collect images at 120 fps during stance. Sagittal motion of the talocrural and subtalar joints were analyzed. Results: The intersubject mean and standard deviation values for all 58 trials of 13 subjects are reported. Maximum talocrural joint plantarflexion of 11.2 degrees (4.3 degrees of standard deviation) occurred at 11% stance and maximum dorsiflexion of â6.9 degrees (5.6 degrees of standard deviation) occurred at 85%. Maximum subtalar joint plantarflexion of 4.8 degrees (1.0 degrees of standard deviation) occurred at 96% stance and maximum dorsiflexion of â3.6 degrees (2.3 degrees of standard deviation) occurred at 30%. Talocrural and subtalar range of motion values during stance were 18.1 and 8.4 degrees, respectively. Conclusion: Existing fluoroscopic technology was capable of defining sagittal plane talocrural and subtalar motion during gait. These kinematic results compare favorably with more invasive techniques. This type of assessment could support more routine analysis of in vivo bony motion during gait. Clinical Relevance: Fluoroscopic technology offers improved sagittal plane motion evaluation during weight-bearing with potential application in patients with end-stage ankle arthritis, postoperative ankle replacements and fusions, and orthotics and braces
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On the Interface Between LENSÂź Deposited Stainless Steel 304L Repair Geometry and Cast or Machined Components
Laser Engineered Net Shapingâą (LENSÂź) is being evaluated for use as a metal component
repair/modification process. A component of the evaluation is to better understand the characteristics of
the interface between LENS deposited material and the substrate on which it is deposited. A processing
and metallurgical evaluation was made on LENS processed material fabricated for component
qualification tests. A process parameter evaluation was used to determine optimum build parameters
and these parameters were used in the fabrication of tensile test specimens to study the characteristics of
the interface between LENS deposited material and several types of substrates. Analyses of the
interface included mechanical properties, microstructure, and metallurgical integrity. Test samples
were determined for a variety of geometric configurations associated with interfaces between LENS
deposited material and both wrought base material or previously deposited LENS material. Thirteen
different interface configurations were fabricated for evaluation representing a spectrum of deposition
conditions from complete part build, to hybrid substrate-LENS builds, to repair builds for damaged or
re-designed housings. Good mechanical properties and full density were observed for all configurations.
When tested to failure, fracture occurred by ductile microvoid coalescence. The repair and hybrid
interfaces showed the same metallurgical integrity as, and had properties similar to, monolithic LENS
deposits.Mechanical Engineerin
Degenerating families of dendrograms
Dendrograms used in data analysis are ultrametric spaces, hence objects of
nonarchimedean geometry. It is known that there exist -adic representation
of dendrograms. Completed by a point at infinity, they can be viewed as
subtrees of the Bruhat-Tits tree associated to the -adic projective line.
The implications are that certain moduli spaces known in algebraic geometry are
-adic parameter spaces of (families of) dendrograms, and stochastic
classification can also be handled within this framework. At the end, we
calculate the topology of the hidden part of a dendrogram.Comment: 13 pages, 8 figure
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