515 research outputs found
Quick response targeting program
Computer program generates and verifies operational launch vehicle targeting presettings for lunar free-return missions and lunar landing missions. Program is applicable in astronomy and nuclear physics, and in areas where improved targeting techniques are valuable
On phenomenon of scattering on resonances associated with discretisation of systems with fast rotating phase
Numerical integration of ODEs by standard numerical methods reduces a
continuous time problems to discrete time problems. Discrete time problems have
intrinsic properties that are absent in continuous time problems. As a result,
numerical solution of an ODE may demonstrate dynamical phenomena that are
absent in the original ODE. We show that numerical integration of system with
one fast rotating phase lead to a situation of such kind: numerical solution
demonstrate phenomenon of scattering on resonances that is absent in the
original system.Comment: 10 pages, 5 figure
Osseointegrated total knee replacement connected to a lower limb prosthesis: 4 cases
Background and purpose
Osseointegrated implants are an alternative for prosthetic attachment in individuals with amputation who are unable to wear a socket. However, the load transmitted through the osseointegrated fixation to the residual tibia and knee joint can be unbearable for those with transtibial amputation and knee arthritis. We report on the feasibility of combining total knee replacement (TKR) with an osseointegrated implant for prosthetic attachment.
Patients and methods
We retrospectively reviewed all 4 cases (aged 38–77 years) of transtibial amputations managed with osseointegration and TKR in 2012–2014. The below-the-knee prosthesis was connected to the tibial base plate of a TKR, enabling the tibial residuum and knee joint to act as weight-sharing structures. A 2-stage procedure involved connecting a standard hinged TKR to custom-made implants and creation of a skin-implant interface. Clinical outcomes were assessed at baseline and after 1–3 years of follow-up using standard measures of health-related quality of life, ambulation, and activity level including the questionnaire for transfemoral amputees (Q-TFA) and the 6-minute walk test.
Results
There were no major complications, and there was 1 case of superficial infection. All patients showed improved clinical outcomes, with a Q-TFA improvement range of 29–52 and a 6-minute walk test improvement range of 37–84 meters.
Interpretation
It is possible to combine TKR with osseointegrated implants
Fabrication of chromium oxide nanoparticles by laser-induced deposition from solution
We have successfully deposited well-dispersed nanoscale chromium oxide particles by laser-induced solution deposition (LISD) from solution with CrCl2 and organic solvents. The particles have narrow distributions about three sizes: 230, 350 and 400 nm and are uniform in composition and contain little contamination. We show that LISD is a new technique for producing nanoparticle chromium oxides with uniform composition, controllable size and high yield
Kansas environmental and resource study: A Great Plains model
The author has identified the following significant results. Improvement in the land use classification accuracy of ERTS-1 MSS multi-images over Kansas can be made using two distances between neighboring grey tone N-tuples instead of one distance. Much more information is contained texturally than spectrally on the Kansas image. Ground truth measurements indicate that reflectance ratios of the 545 and 655 nm wavebands provide an index of plant development and possibly physiological stress. Preliminary analysis of MSS 4 and 5 channels substantiate the ground truth interpretation. Results of the land use mapping experiment indicate that ERTS-1 imagery has major potential in regionalization. The ways in which land is utilized within these regions may then be studied more effectively than if no adequate regionalization is available. A model for estimating wheat yield per acre has been applied to acreage estimates derived from ERTS-1 imagery to project the 1973 wheat yields for a ten county area in southwest Kansas. The results are within 3% of the preharvest estimates for the same area prepared by the USDA. Visual identification of winter wheat is readily achieved by using a temporal sequence of images. Identification can be improve by stratifying the project area into subregions having more or less homogeneous agricultural practices and crop mixes
Fabrication of chromium oxide nanoparticles by laser-induced deposition from solution
We have successfully deposited well-dispersed nanoscale chromium oxide particles by laser-induced solution deposition (LISD) from solution with CrCl2 and organic solvents. The particles have narrow distributions about three sizes: 230, 350 and 400 nm and are uniform in composition and contain little contamination. We show that LISD is a new technique for producing nanoparticle chromium oxides with uniform composition, controllable size and high yield
Freezing and chemical preservatives alter the stable isotope values of carbon and nitrogen of the Asiatic clam (Corbicula fluminea)
We tested the impacts of most common sample preservation methods used for aquatic sample materials on the stable isotope ratios of carbon and nitrogen in clams, a typical baseline indicator organism for many aquatic food web studies utilising stable isotope analysis (SIA). In addition to common chemical preservatives ethanol and formalin, we also assessed the potential impacts of freezing on δ¹³C and δ¹⁵N values and compared the preserved samples against freshly dried and analysed samples. All preservation methods, including freezing, had significant impacts on δ¹³C and δ¹⁵N values and the effects in general were greater on the carbon isotope values (1.3-2.2% difference) than on the nitrogen isotope values (0.9-1.0% difference). However, the impacts produced by the preservation were rather consistent within each method during the whole 1 year experiment allowing these to be accounted for, if clams are intended for use in retrospective stable isotope studies
The impact of the COVID-19 pandemic on the medical care and health-care behaviour of patients with lupus and other systemic autoimmune diseases: a mixed methods longitudinal study
Objective: The aim was to explore the self-reported impact of the COVID-19 pandemic on changes to care and behaviour in UK patients with systemic autoimmune rheumatic diseases, to help ensure that patient experiences are considered in future pandemic planning. Methods: This was a longitudinal mixed methods study, with a cohort completing baseline surveys in March 2020 and follow-up surveys in June 2020 (n = 111), combined with thematic analysis of the LUPUS UK forum and participant interviews (n = 28). Results: Cancellations of routine care and difficulties in accessing medical support contributed to some participants deteriorating physically, including reports of hospitalizations. The majority of participants reported that fear of COVID-19 and disruptions to their medical care had also adversely impacted their mental health. Feeling medically supported during the pandemic was correlated with multiple measures of mental health and perceptions of care, including the Warwick-Edinburgh mental well-being score (r = 0.44, P = 0.01). Five themes were identified: detrimental reduction in care; disparities in contact and communication (medical security vs abandonment sub-theme); perceived and actual endangerment; the perfect storm of reduced clinician ability to help and increased patient reticence to seek help; and identifying the patients most vulnerable to reduced medical care. Conclusion: The diversion of resources away from chronic disease care was perceived by many participants to have caused adverse outcomes. Fear about increased vulnerability to COVID-19 was high, contributing to health-care-avoidant behaviours. This study also highlights the influence of clinician accessibility and patients feeling medically supported on multiple measures of physical and mental health
Disease epidemic and a marine heat wave are associated with the continental-scale collapse of a pivotal predator (Pycnopodia helianthoides)
Multihost infectious disease outbreaks have endangered wildlife, causing extinction of frogs and endemic birds, and widespread declines of bats, corals, and abalone. Since 2013, a sea star wasting disease has affected > 20 sea star species from Mexico to Alaska. The common, predatory sunflower star (Pycnopodia helianthoides), shown to be highly susceptible to sea star wasting disease, has been extirpated across most of its range. Diver surveys conducted in shallow nearshore waters (n = 10,956; 2006-2017) from California to Alaska and deep offshore (55 to 1280 m) trawl surveys from California to Washington (n = 8968; 2004-2016) reveal 80 to 100% declines across a similar to 3000-km range. Furthermore, timing of peak declines in nearshore waters coincided with anomalously warm sea surface temperatures. The rapid, widespread decline of this pivotal subtidal predator threatens its persistence and may have large ecosystem-level consequences
Abnormal Ocular Pneumoplethysmographic Results in Unilateral Neovascular Glaucoma.
Little is known about the predictive value of ocular pneumoplethysmography in patients with ophthalmic disease. We evaluated eight patients with unilateral increased intraocular pressure due to neovascular glaucoma who did not have evidence of severe extracranial carotid stenosis by duplex scanning and continuous-wave Doppler ultrasound. The ophthalmic systolic pressure measured by ocular pneumoplethysmography was decreased in the affected eye of all eight patients, indicating that neovascular glaucoma may be a cause of abnormal ocular pneumoplethysmographic results. Patients with neovascular glaucoma tended to have larger interocular ophthalmic systolic pressure differences than other patients with false-positive ocular pneumoplethysmographic results by noninvasive criteria
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