1,720,963 research outputs found
Effect of Electrical Conductivity Levels of Nutrient Solution on Growth, Gas Exchanges and Yield of Two Gerbera Cultivars in Soilless System
No full textThe response of two Gerbera cultivars to EC level of nutrient solution, a greenhouse experiment was carried out in Naples from April to November 2002, on 1-year plants fertigated with two EC values, 1.6 dS m-1 and 2.4 dS m-1, at pH 6.0. Plants of Brittani and Golden Serena cultivars were grown in pot, on 7:3 mixture (v/v) of peat and perlite. Water and fertilizers were supplied by a drip-system and the number of pulses was 1 per day from April to June and from September to October, 2 per day in July and August, and 3 per week in November. 400 ml of nutrient solution was applied per pulse, whit about 20% of leaching. Gas exchanges were unaffected by EC level of nutrient solution and Gerbera cultivars and higher net photosynthesis (15.02 mol CO2 m-2 sec-1) was recorded in spring months, with the maximum transpiration rate in may (11.18 mmol m-2 s-1). During the 8-month period, daily water uptake was higher in plants fertigated with 2.4 dS m-1 compared with 1.6 dS m-1 (471 vs 423 ml per plant), according with the difference in leaf area (65.8 vs 60.4 dm2) and yield (34.3 vs 29.9 flowers). Higher EC level increased the content of N (3.89 vs 3.36% DM), N-NO3 (0.56 vs 0.39%), P (0.14 vs 0.10%) and K (4.30 vs 2.89%) in young leaves. No difference was found between the cultivars in water uptake and nutrient composition of leaves. Brittani yielded higher number of flowers (35.2 vs 29.1 per plant)
Neural machine registration for motion correction in breast DCE-MRI
No full textCancer is one of the leading causes of death in the western world, with medical imaging playing a key role for early diagnosis. Focusing on breast cancer, one of the emerging imaging methodologies is Dynamic Contrast Enhanced-Magnetic Resonance Imaging (DCE-MRI). The flip side of using DCE-MRI is in its long acquisition times that often causes the patient to move. This results in motion artefacts, namely distortions in the acquired image that can affect DCE-MRI analysis. A possible solution consists in the use of Motion Correction Techniques (MCTs), i.e. procedures intended to re-align the post-contrast image to the corresponding pre-contrast (reference) one. This task is particularly critic in DCE-MRI, due to brightness variations introduced in post-contrast images by the contrast-agent flowing. To face this problem, in this work we introduce a new MCT for breast DCE-MRI leveraging Physiologically Based PharmacoKinetic (PBPK) modelling and Artificial Neural Networks (ANN) to determine the most suitable physiologically-compliant transformation. To this aim, we propose a Neural Registration Network relying on a very task-specific loss function explicitly designed to take into account the contrast agent flowing while enforcing a correct re-alignment. We compared the obtained results against some conventional motion correction techniques, evaluating the performance on a patient-by-patient basis. Results show that the proposed approach results to be the best performing even when compared against other techniques designed to take into account for brightness variations
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Effect of Electrical Conductivity Levels of Nutrient Solution on Growth, Gas Exchanges and Yield of Two Gerbera Cultivars in Soilless System
No full textThe response of two Gerbera cultivars to EC level of nutrient solution, a greenhouse experiment was carried out in Naples from April to November 2002, on 1-year plants fertigated with two EC values, 1.6 dS m-1 and 2.4 dS m-1, at pH 6.0. Plants of Brittani and Golden Serena cultivars were grown in pot, on 7:3 mixture (v/v) of peat and perlite. Water and fertilizers were supplied by a drip-system and the number of pulses was 1 per day from April to June and from September to October, 2 per day in July and August, and 3 per week in November. 400 ml of nutrient solution was applied per pulse, whit about 20% of leaching. Gas exchanges were unaffected by EC level of nutrient solution and Gerbera cultivars and higher net photosynthesis (15.02 mol CO2 m-2 sec-1) was recorded in spring months, with the maximum transpiration rate in may (11.18 mmol m-2 s-1). During the 8-month period, daily water uptake was higher in plants fertigated with 2.4 dS m-1 compared with 1.6 dS m-1 (471 vs 423 ml per plant), according with the difference in leaf area (65.8 vs 60.4 dm2) and yield (34.3 vs 29.9 flowers). Higher EC level increased the content of N (3.89 vs 3.36% DM), N-NO3 (0.56 vs 0.39%), P (0.14 vs 0.10%) and K (4.30 vs 2.89%) in young leaves. No difference was found between the cultivars in water uptake and nutrient composition of leaves. Brittani yielded higher number of flowers (35.2 vs 29.1 per plant)
MRI findings, surgical treatment and follow-up of a myelomeningocele with tethered spinal cord syndrome in a cat
No full textA 7-month-old male neutered cat was referred for paraparesis and painful sensation at the level of T13 vertebra where a dermal cyst was observed. Spine radiographs and magnetic resonance imaging (MRI) showed a well-encapsulated cyst communicating with the meninges and spinal cord, suggestive of hydromyelia and myelodysplasia. Dorsal laminectomy was performed and the cyst was completely removed. The day after surgery, the cat was ambulatory paraparetic. Involuntary defecation was observed for only a few days. The surgical specimen was cystic and covered by skin. Microscopic examination revealed a hollow hemispheric mass of glial fibrillary acidic protein (GFAP)-positive neural tissue lined by ependyma and formed of glia and vascular structures consistent with myelomeningocele (MMC). Only anecdotal descriptions of MMC have been published in the veterinary literature, mainly in the lumbosacral spinal cord. To the authors' knowledge, this is the first report of a MMC with tethered spinal cord syndrome in a cat successfully treated surgically
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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