1,140 research outputs found

    Assessment of the Accuracy of a Multi-Beam LED Scanner Sensor for Measuring Olive Canopies

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    MDPI. CC BYCanopy characterization has become important when trying to optimize any kind of agricultural operation in high-growing crops, such as olive. Many sensors and techniques have reported satisfactory results in these approaches and in this work a 2D laser scanner was explored for measuring canopy trees in real-time conditions. The sensor was tested in both laboratory and field conditions to check its accuracy, its cone width, and its ability to characterize olive canopies in situ. The sensor was mounted on a mast and tested in laboratory conditions to check: (i) its accuracy at different measurement distances; (ii) its measurement cone width with different reflectivity targets; and (iii) the influence of the target’s density on its accuracy. The field tests involved both isolated and hedgerow orchards, in which the measurements were taken manually and with the sensor. The canopy volume was estimated with a methodology consisting of revolving or extruding the canopy contour. The sensor showed high accuracy in the laboratory test, except for the measurements performed at 1.0 m distance, with 60 mm error (6%). Otherwise, error remained below 20 mm (1% relative error). The cone width depended on the target reflectivity. The accuracy decreased with the target density

    Characterization of the Adherence of Clostridium difficile Spores: The Integrity of the Outermost Layer Affects Adherence Properties of Spores of the Epidemic Strain R20291 to Components of the Intestinal Mucosa

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    Indexación: Web of Science.Clostridium difficile is the causative agent of the most frequently reported nosocomial diarrhea worldwide. The high incidence of recurrent infection is the main clinical challenge of C. difficile infections (CBI). Formation of C. difficile spores of the epidemic strain R20291 has been shown to be essential for recurrent infection and transmission of the disease in a mouse model. However, the underlying mechanisms of how these spores persist in the colonic environment remains unclear. In this work, we characterized the adherence properties of epidemic R20291 spores to components of the intestinal mucosa, and we assessed the role of the exosporium integrity in the adherence properties by using cdeC mutant spores with a defective exosporium layer. Our results showed that spores and vegetative cells of the epidemic R20291 strain adhered at high levels to monolayers of Caco-2 cells and mucin. Transmission electron micrographs of Caco-2 cells demonstrated that the hair-like projections on the surface of R20291 spores are in close proximity with the plasma membrane and microvilli of undifferentiated and differentiated monolayers of Caco-2 cells. Competitive-binding assay in differentiated Caco-2 cells suggests that spore-adherence is mediated by specific binding sites. By using spores of a cdeC mutant we demonstrated that the integrity of the exosporium layer determines the affinity of adherence of C. difficile spores to Caco-2 cells and mucin. Binding of fibronectin and vitronectin to the spore surface was concentration-dependent, and depending on the concentration, spore-adherence to Caco-2 cells was enhanced. In the presence of an aberrantly-assembled exosporium (cdeC spores), binding of fibronectin, but not vitronectin, was increased. Notably, independent of the exosporium integrity, only a fraction of the spores had fibronectin and vitronectin molecules binding to their surface. Collectively, these results demonstrate that the integrity of the exosporium layer of strain R20291 contributes to selective spore adherence to components of the intestinal mucosa.http://journal.frontiersin.org/article/10.3389/fcimb.2016.00099/ful

    First attempts to obtain a reference drift curve for traditional olive grove's plantations following ISO 22866

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    The current standard for the field measurements of spray drift (ISO 22866) is the only official standard for drift measurements in field conditions for all type of crops, including bushes and trees. A series of field trials following all the requirements established in the standard were arranged in a traditional olive grove in Córdoba (south of Spain). The aims of the study were to evaluate the applicability of the current standard procedure to the particular conditions of traditional olive trees plantations, to evaluate the critical requirements for performing the tests and to obtain a specific drift curve for such as important and specific crop as olive trees in traditional plantations, considering the enormous area covered by this type of crop all around the world.The authors thank the Ministry of Economy and Competitiveness of the Spanish Government for their economic support through the pre-commercial procurement Mecaolivar project, financed with FEDER funds, and the AgVANCE project (AGL2013-48297-C2-1-R). The first author acknowledges the support of the Spanish Ministry of Education, Culture and SportPostprint (updated version

    Using Green Fluorescent Protein to Correlate Temperature and Fluorescence Intensity into Bacterial Systems

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    The unique and stunning spectroscopic properties of Green Fluorescent Protein (GFP) from the jellyfish Aequorea victoria, not to mention of its remarkable structural stability, have made it one of the most widely studied and used molecular tool in medicine, biochemistry, and cell biology. Its high fluorescent quantum yield is due to its chromophore, structure responsible of emitting green visible light when excited at 395 nm. Although it is noteworthy that there is enormous available information of the wonderful luminescent properties of GFP, the fact is that there are features and properties unexplored yet, particulary about its capabilities as molecular reporter in several biological processes. In this work, we used recombinant DNA technology to express the protein in bacteria; prepared the bacterial system both in liquid and solid media, and assembled an experimental set to expose those media to a laser beam; thereby we excited the protein chromophore and used emission spectroscopy in order to observe variations in fluorescence when the bacterial system is exposed to different temperatures

    Reducing spray drift by adapting the spraying equipment to the canopy shape in olive orchards with isolated trees

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    The lack of specificity of the spraying equipment commonly used in olive orchards is a remarkable problem, for not allowing farmers to apply adjusted pesticide doses to their trees, making necessary to spray very high liquid volumes that increase the environmental pollution risk. In this context, three prototypes were specially developed to increase the application efficiency in olive orchards with isolated trees, which represent 98% of the olive harvested area in Spain.Postprint (published version

    Scoping review of measures of treatment burden in patients with multimorbidity: advancements and current gaps

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    Objectives: To identify, assess, and summarize the measures to assess burden of treatment in patients with multimorbidity (BoT-MMs) and their measurement properties. Study Design and Setting: MEDLINE via PubMed was searched from inception until May 2021. Independent reviewers extracted data from studies in which BoT-MMs were developed, validated, or reported as used, including an assessment of their measurement properties (e.g., validity and reliability) using the COnsensus-based Standards for the selection of health Measurement INstruments. Results: Eight BoT-MMs were identified across 72 studies. Most studies were performed in English (68%), in high-income countries (90%), without noting urban-rural settings (90%). No BoT-MMs had both sufficient content validity and internal consistency; some measurement properties were either insufficient or uncertain (e.g., responsiveness). Other frequent limitations of BoT-MMs included absent recall time, presence of floor effects, and unclear rationale for categorizing and interpreting raw scores. Conclusion: The evidence needed for use of extant BoT-MMs in patients with multimorbidity remains insufficiently developed, including that of suitability for their development, measurement properties, interpretability of scores, and use in low-resource settings. This review summarizes this evidence and identifies issues needing attention for using BoT-MMs in research and clinical practice

    Factors associated with smoking among tuberculosis patients in Spain

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    Altres ajuts: This work was made possible by a grant from the Spanish Society of Pneumology and Thoracic Surgery, SEPAR 2011.To determine the prevalence of smoking and analyze associated factors in a cohort of patients diagnosed with tuberculosis (TB) in Spain between 2006 and 2013. Multicenter, cross-sectional, descriptive, observational study using a national database of TB patients, using logistic regression to calculate odds ratios (OR) and confidence intervals (CI). We analyzed 5,846 cases (62 % men, mean age 39 years, 33 % foreigners). 23.4 % were alcohol abuser, 1.3 % were injected drug users (IDU), 4.6 % were co-infected with HIV, and 7.5 % had a history of TB treatment. 6.6 % and 0.8 % showed resistance to one and multiple drugs, respectively. The predominant clinical presentation was pulmonary (71 %) with a cavitary radiological pattern in 32.8 % of cases. 82 % of cases were confirmed microbiologically, and 54 % were smear-positive microscopy. 2,300 (39.3 %) patients were smokers. The following factors were associated with smoking: male sex (OR = 2.26;CI:1.97;2.60), Spanish origin (OR = 2.79;CI:2.40-3.24), alcoholism (OR = 2.85;CI:2.46;3.31), IDU (OR = 2.78;CI:1.48;5.52), homelessness (OR = 1.99;CI:1.14-3.57), pulmonary TB (OR = 1.61;CI:1.16;2.24), cavitary radiological pattern (OR = 1.99;CI:1.43;2.79) and a smear-positive microscopy at the time of diagnosis (OR = 1.39;CI:1.14;1.17). The prevalence of smoking among TB patients is high. Smokers with TB have a distinct sociodemographic, clinical, radiological and microbiological profile to non-smokers
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