1,141 research outputs found
Population dynamics of Fusarium oxysporum f.sp. niveum and F. solani f.sp. cucurbitae in commercial watermelon fields in Tunisia
Experiments were conducted in field plots to evaluate the level and the dynamic population of Fusarium species propagules of in three commercial watermelon fields inTunisia surveyed two successives years. Populations of Fusarium oxysporum f. sp. niveum and F. solani f. sp. cucurbitae in naturally infested fields of watermelon were enumerated by soil dilution method and subsequent pathogenicity tests. The results showed that Fsc colonies number recovered from the field soils was higher than the value of Fon colonies,in each field and for the two years. Before planting, the density of Fsc propagules in thefield soils was higher than the number of Fon colonies, in each field and for the two years.It varies from 193 to 128 propagules/g soil for the 1st year and between 986 to 568propagules/g soil in the 2nd year for field II. The highest inoculum density of Fsc was found at Field II (986.67±172.09 CFU g-1 soil) during the 2nd year, before plantation. Pathogenicity test revealed that for pathogens isolated from the deep 20-30 cm, the number of pathogenic colonies is relatively lower and counted between 40 to 70%
Perspectivas epistemológicas no estudo científico e a avaliação clínica das funções executivas
En este artículo se examinan perspectivas epistemológicas que han moldeado e influenciado la búsqueda científica orientada hacia comprender aquello que los neuropsicólogos denominan las "funciones ejecutivas (FE). El término funciones ejecutivas se refiere a aspectos de control de la cognición y la conducta. Las ideas expuestas en este manuscrito presuponen que la orientación epistemológica de una persona determina la manera en la que ella conceptualiza la interacción entre las funciones cerebrales y su entorno físico. Cada una de esas orientaciones conlleva suposiciones acerca del modo como operan las FE y, por ende, el modo como deben ser evaluadas. Hasta fechas recientes esto se había abordado principalmente desde el punto de vista de dos perspectivas teóricas. Una de ellas, la analítica, tiene sus raíces en el movimiento positivista. La otra, también conocida como "ciencia romántica" es sintética, y provee las bases del trabajo científico del muy celebrado neuropsicólogo ruso A.R. Luria. Una tercera perspectiva, formulada en el marco de la "cognición corpórea", ha sido propuesta en los últimos 20 años, y está más estrechamente asociada con los trabajos de Francisco Varela. Se examina aquí, por medio de una revisión reflexiva e integradora de la literatura pertinente, la manera como esas tres perspectivas epistemológicas han influido sobre la investigación y la práctica clínica de la neuropsicología.In this article, epistemological perspectives that have shaped and affected the scientific quest for understanding what neuropsychologists term "executive functions" are reviewed. Executive functions refer to the control functions of cognition and behavior. The underlying thesis of the paper is that one's epistemological orientation determines how one sees the interaction between brain functions and our status in the world. Each different orientation thus carries with it implications with regard to how executive functions operate, as well as how, therefore, one should try to assess them. Until recently, these functions were approached through two primary epistemological points of view. One is analytic, which has its roots in the positivistic movement. The other approach is synthetic, otherwise known as "romantic science", and forms the basis of the work of the prominent Russian neuropsychologist A.R. Luria. A third epistemological perspective, articulated under the umbrella of 'embodied cognition' approaches, has been advanced in the last 20 years, and is associated most closely with the work of Francisco Varela. A review of, and reflection on how these perspectives have affected research and clinical practice in neuropsychology is provided.Neste artigo examinam-se as perspectivas epistemológicas que moldaram e influenciaram a busca científica orientada à compreender aquilo que os neuropsicólogos denominam as "funções executivas (FE). O termo funções executivas se refere a aspectos de controle da cognição e a conduta. As ideias expostas neste manuscrito pressupõem que a orientação epistemológica de uma pessoa determina a maneira em que ela conceitualiza a interação entre as funções cerebrais e seu entorno físico. Cada uma dessas orientações leva a suposições sobre o modo como operam as FE e, portanto, o modo como devem ser avaliadas. Até datas recentes isto havia sido abordado principalmente desde o ponto de vista de duas perspectivas teóricas. Uma delas, a analítica, tem suas raízes no movimento positivista. A outra, também conhecida como "ciência romântica" é sintética, e fornece as bases do trabalho científico do muito celebrado neuropsicólogo russo A.R. Luria. Uma terceira perspectiva, formulada no marco da "cognição corpórea", foi proposta nos últimos 20 anos, e está mais estreitamente associada com os trabalhos de Francisco Varela. Examina-se aqui, através de uma revisão reflexiva e integradora da literatura pertinente, a maneira como essas três perspectivas epistemológicas influíram sobre a pesquisa e a prática da neuropsicologia
Rational parameterizations approach for solving equations in some dynamical systems problems
We show how the use of rational parameterizations facilitates the study of the number of solutions of many systems of equations involving polynomials and square roots of polynomials. We illustrate the effectiveness of this approach, applying it to several problems appearing in the study of some dynamical systems. Our examples include Abelian integrals, Melnikov functions and a couple of questions in Celestial Mechanics: the computation of some relative equilibria and the study of some central configurations
Obstructive Sleep Apnoea Syndrome, Endothelial Function and Markers of Endothelialization. Changes after CPAP
STUDY OBJECTIVES: This study tries to assess the endothelial function in vivo using flow-mediated dilatation (FMD) and several biomarkers of endothelium formation/restoration and damage in patients with obstructive sleep apnoea (OSA) syndrome at baseline and after three months with CPAP therapy. DESIGN: Observational study, before and after CPAP therapy. SETTING AND PATIENTS: We studied 30 patients with apnoea/hypopnoea index (AHI) >15/h that were compared with themselves after three months of CPAP therapy. FMD was assessed non-invasively in vivo using the Laser-Doppler flowmetry. Circulating cell-free DNA (cf-DNA) and microparticles (MPs) were measured as markers of endothelial damage and the vascular endothelial growth factor (VEGF) was determined as a marker of endothelial restoration process. MEASUREMENTS AND RESULTS: After three month with CPAP, FMD significantly increased (1072.26 ± 483.21 vs. 1604.38 ± 915.69 PU, p< 0.005) cf-DNA and MPs significantly decreased (187.93 ± 115.81 vs. 121.28 ± 78.98 pg/ml, p<0.01, and 69.60 ± 62.60 vs. 39.82 ± 22.14 U/μL, p<0.05, respectively) and VEGF levels increased (585.02 ± 246.06 vs. 641.11 ± 212.69 pg/ml, p<0.05). These changes were higher in patients with more severe disease. There was a relationship between markers of damage (r = -0.53, p<0.005) but not between markers of damage and restoration, thus suggesting that both types of markers should be measured together. CONCLUSIONS: CPAP therapy improves FMD. This improvement may be related to an increase of endothelial restoration process and a decrease of endothelial damage
Equivalence of two optical quality metrics to predict the visual acuity of multifocal pseudophakic patients
This article studies the relationship between two metrics, the area under the modulation transfer function (MTFa) and the energy efficiency (EE), and their ability to predict the visual quality of patients implanted with multifocal intraocular lenses (IOLs). The optical quality of IOLs is assessed in vitro using two metrics, the MTFa and EE. We measured them for three different multifocal IOLs with parabolic phase profile using image formation, through-focus (TF) scanning, three R, G, B wavelengths, and two pupils. We analyzed the correlation between MTFa and EE. In parallel, clinical defocus curves of visual acuity (VA) were measured and averaged from sets of patients implanted with the same IOLs. An excellent linear correlation was found between the MTFa and EE for the considered IOLs, wavelengths and pupils (R2 > 0.9). We computed the polychromatic TF-MTFa, TF-EE, and derived mathematical relationships between each metrics and clinical average VA. MTFa and EE proved to be equivalent metrics to characterize the optical quality of the studied multifocal IOLs and also in terms of clinical VA predictability
Correlation between the TiO<sub>2</sub> encapsulation layer on Pt and its electrochemical behavior
Credence cues of pork are more important than consumers' culinary skills to boost their purchasing intention
The role of consumers' culinary skills on purchasing cues of pork, with emphasis on niche demands (outdoor husbandry and/or certified organic), was assessed in cross-country regions of Spain (Catalonia and Aragon) and Portugal (North). A sample of 974 respondents answered an on-line survey with questions regarding consumer purchasing habits, product involvement and intrinsic and credence attributes. They also chose between two contrasting boneless pork loins and express willingness to pay (WTP) for different product scenarios with different pig farm facilities and for organic pork standards. Two optimal segments were identified based on food-related habits: ‘uninvolved’ and ‘innovative cook lovers’, both similarly balanced across socio-demographics, score for credence attributes or consumer involvement dimensions. Overall mean WTP premium across countries was 11.8% for marbled pork, 20.0% for outdoor pork and 24.3% for organic logo stamp. Credence cues of pork claiming health issues (absence of antibiotics and hormone residues) rather than consumers' culinary skills defined the WTP for niche pork in these regions
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