1,350 research outputs found
Mathematical Genesis of the Spatio-Temporal Covariance Functions
Obtaining new and flexible classes of nonseparable spatio-temporal covariances have resulted in a key point of research in the last years within the context of spatiotemporal Geostatistics. Approach: In general, the literature has focused on the problem of full symmetry and the problem of anisotropy has been overcome. Results: By exploring mathematical properties of positive definite functions and their close connection to covariance functions we are able to develop new spatio-temporal covariance models taking into account the problem of spatial anisotropy. Conclusion/Recommendations: The resulting structures are proved to have certain interesting mathematical properties, together with a considerable applicability.Spatial anisotropy, bernstein and complete monotone functions, spatio-temporal geostatistics, positive definite functions, space-time modeling, spatio-temporal data
Impact of the application of humic acid and sodium nitroprusside on nickel toxicity: Analysis of relative gene expression
Nickel (Ni) is an essential micronutrient for plants but in high concentrations may turn toxic. This paper discusses the potential role of humic acid (HA) and sodium nitroprusside in modulating or preventing oxidative stress in rice plants. Three genes [superoxide dismutase (SOD) glutathione reductase (GR) and ascorbate peroxidase (APx) were selected for an expression study using a real time PCR technique. Three different treatments (T1 = nickel [nickel chloride (NiCl2·6H2O)] 300 mg L-1, T2 = nickel-humic acid, T3 = nickel-sodium nitroprusside) were used to determine the effect of humic acid and sodium nitroprusside on nickel toxicity in rice plants. Rice plants grown in T2 appeared green and well developed. In leaves and roots, the expression of superoxide dismutase and ascorbate peroxidase was higher in T3 (nickel-sodium nitroprusside); glutathione reductase expression in roots was lower in T1 (sand with Ni solution) compared to T2 (nickel 300 mg L-1 and HA) where the expression was higher; significant differences were found between both treatments. In leaves, the behavior of this gene was similar in all  treatments. This research suggests that nickel toxicity cannot be diminished when HA or SNP are used, and they induce oxidative stress in rice plants.Key words: Nickel toxicity, heavy metals, gene expression, oxidative stress
Intravitreal anti-VEGF therapy for choroidal neovascularisation secondary to pathological myopia: 4-year outcome
OBJECTIVE:
To report the visual outcome after 4-year follow-up in a series of highly myopic eyes with choroidal neovascularisation (CNV) treated with antivascular endothelial growth factor (anti-VEGF) drugs.
METHODS:
A retrospective, non-randomised, multicentre, consecutive, interventional case series study was performed. 92 highly myopic eyes with subfoveal CNV were treated with intravitreal injection (IVI) of anti-VEGF. The initial protocol (1 vs 3 injections) was dictated by surgeons' preferences and followed by an as-needed monthly regime. Best-corrected visual acuity (BCVA) was evaluated at baseline and then monthly. The primary aim was to analyse BCVA changes. The effect of age, spherical equivalent (SE) and treating drug were evaluated as secondary objectives.
RESULTS:
The mean age of the patients was 57 years (SD 14, range 30-93). The mean number of letters read was 46.1 (SD 16.8, range 5-70) at baseline, 55.5 (SD 18.6, range 10-85) at 12 months, 50.1 (SD 20.1, range 5-82) at 24 months, 54.2 (SD 21.9, range 2-85) at 36 months and 53.1 (SD 22.5, range 1-83) at 48 months (p=0.000, initial vs 12, 24 and 36 months; p=0.01 initial vs 48 months; Student t test for paired data). The mean total number of IVI was 4.9 (SD 5.4, range 1-29). SE and treating drug had no influence on the final visual outcome and number of injections required.
CONCLUSIONS:
Intravitreal bevacizumab and ranibizumab are effective therapies and show similar clinical effects in highly myopic CNV. Visual acuity gain is maintained at 4-year follow-up
Old drugs with new skills: fenoprofen as an allosteric enhancer at melanocortin receptor 3
This project was supported by Queen Mary Innovation Ltd Proof of Concept Fund (2012/13) and The William Harvey Research Foundation
Mathematical Genesis of the Spatio-Temporal Covariance Functions
Obtaining new and flexible classes of nonseparable spatio-temporal
covariances have resulted in a key point of research in the last years within the context of spatiotemporal
Geostatistics. Approach: In general, the literature has focused on the problem of full
symmetry and the problem of anisotropy has been overcome. Results: By exploring mathematical
properties of positive definite functions and their close connection to covariance functions we are able
to develop new spatio-temporal covariance models taking into account the problem of spatial
anisotropy. Conclusion/Recommendations: The resulting structures are proved to have certain
interesting mathematical properties, together with a considerable applicability
Recommended from our members
Trace elements and lead isotopic composition of copper deposits from the eastern part of the Internal Zone of the Betic Cordillera (SE Iberia): application to provenance of archaeological materials
This paper presents trace element compositions and lead isotope analyses by MC-ICP-MS of 34 copper ore samples from the Internal Zone of the Betic Range, Southeast Spain. Samples were collected during a fieldwork campaign in the mines of Cerro Minado, Pinar de BĂ©dar, Sierra Cabrera and Sierra Almagrera/HerrerĂas. Most samples are copper oxide minerals from the near surface alteration of the sulfide ore deposits. The aim of the study is to supplement the existing reference data bank on lead isotopic compositions of ancient copper mines from the Iberian Peninsula, complementing this data with trace element compositions. The latter can be useful for discriminating when isotopic overlaps occur. This characterisation will be of great usefulness for provenancing further archaeological materials. Lead isotope ratios range from 18.603 to 20.327 (206Pb/204Pb); from 15.685 to 15.779 (207Pb/204Pb) and from 38.728 to 39.702 (208Pb/204Pb). Data from the literature analysed by TIMS have been also considered for comparison although the larger analytical error is highlighted, especially for isotope 204Pb. The lead isotopic signature of the analysed samples shows three separate isotopic fields. These fields are also consistent with differences in compositions evidenced by principal component analyses
Gait disorders are associated with non-cardiovascular falls in elderly people: a preliminary study
BACKGROUND: The association between unexplained falls and cardiovascular causes is increasingly recognized. Neurally mediated cardiovascular disorders and hypotensive syndromes are found in almost 20 percent of the patients with unexplained falls. However, the approach to these patients remains unclear. Gait assessment might be an interesting approach to these patients as clinical observations suggests that those with cardiovascular or hypotensive causes may not manifest obvious gait alterations. Our primary objective is to analyze the association between gait disorders and a non-cardiovascular cause of falls in patients with unexplained falls. A second objective is to test the sensitivity and specificity of a gait assessment approach for detecting non-cardiovascular causes when compared with intrinsic-extrinsic classification. METHODS: Cross-sectional study performed in a falls clinic at a university hospital in 41 ambulatory elderly participants with unexplained falls. Neurally mediated cardiovascular conditions, neurological diseases, gait and balance problems were assessed. Gait disorder was defined as a gait velocity < 0.8 m/s or Tinetti Gait Score <9. An attributable etiology of the fall was determined in each participant. Comparisons between the gait assessment approach and the attributable etiology regarding a neurally mediated cardiovascular cause were performed. Fisher exact test was used to test the association hypothesis. Sensitivity and specificity of gait assessment approach and intrinsic-extrinsic classification to detect a non-cardiovascular mediated fall was calculated with 95% confidence intervals (CI95%). RESULTS: A cardiovascular etiology (orthostatic and postprandial hypotension, vasovagal syndrome and carotid sinus hypersensitivity) was identified in 14% of participants (6/41). Of 35 patients with a gait disorder, 34 had a non-cardiovascular etiology of fall; whereas in 5 out of 6 patients without a gait disorder, a cardiovascular diagnosis was identified (p < 0.001). Sensitivity and specificity of the presence of gait disorder for identifying a non-cardiovascular mediated cause was 97.1% (CI95% = 85–99) and 83% (CI95% = 36–99), respectively. CONCLUSION: In community dwelling older persons with unexplained falls, gait disorders were associated with non-cardiovascular diagnosis of falls. Gait assessment was a useful approach for the detection of a non-cardiovascular mediated cause of falls, providing additional value to this assessment
COVID-19’s impact on care practice for alpha-1-antitrypsin deficiency patients
Alpha-1-antitrypsin deficiency; COVID-19; Patient managementDeficiencia de alfa-1-antitripsina; COVID-19; Gestión del pacienteDeficiència d'alfa-1-antitripsina; COVID-19; Gestió del pacientBackground
Patients with alpha-1 antitrypsin deficiency (AATD), commonly categorized as a rare disease, have been affected by the changes in healthcare management brought about by COVID-19. This study’s aim was to identify the changes that have taken place in AATD patient care as a result of the COVID-19 pandemic in Spain and to propose experts’ recommendations aimed at ensuring humanized and quality care for people with AATD in the post-pandemic situation.
Methods
A qualitative descriptive case study with a holistic single-case design was conducted, using focus groups with experts in AATD clinical management, including 15 health professionals with ties to the Spanish health system (12 pneumologists and 2 hospital pharmacists from 11 different hospitals in Spain) and 1 patient representative.
Results
COVID-19 has had a major impact on numerous aspects of AATD clinical patient management in Spain, including diagnostic, treatment, and follow-up phases. The experts concluded that there is a need to strengthen coordination between Primary Care and Hospital Care and improve the coordination processes across all the organizations and actors involved in the healthcare system. Regarding telemedicine and telecare, experts have concluded that it is necessary to promote this methodology and to develop protocols and training programs. Experts have recommended developing personalized and precision medicine, and patient participation in decision-making, promoting self-care and patient autonomy to optimize their healthcare and improve their quality of life. The possibility of monitoring and treating AATD patients from home has also been proposed by experts. Another result of the study was the recommendation of the need to ensure that plasma donations are made on a regular basis by a sufficient number of healthy individuals.
Conclusion
The study advances knowledge by highlighting the challenges faced by health professionals and changes in AATD patient management in the context of the COVID-19 pandemic. It also proposes experts’ recommendations aimed at ensuring humanized and quality care for people with AATD in the post-pandemic situation. This work could serve as a reference study for physicians on their daily clinical practice with AATD patients and may also provide guidance on the changes to be put in place for the post-pandemic situation.This study was funded by CSL Behring
- …