1,720,994 research outputs found
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
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
Influence of packaging conditions on biogenic amines and fatty acids evolution during 15 months storage of a typical spreadable salami ('Nduja)
No full textThe study evaluated the fatty acids and the biogenic amines (BAs) in ‘Nduja of Spilinga stored in differentpackaging materials (i.e. natural casing under vacuum, glass jar, aluminum tube and OVTENE) during15 months of shelf-life. Raw materials and pepper mixture were analysed as well. BAs concentrationsincreased with time, tyramine (TYR), putrescine (PUT) and cadaverine (CAD) were the most abundant.BAs in natural casing were always higher than those found in glass jar, aluminum tube and OVTENE.Total fatty acids were characterized by higher level of unsaturated fatty acid that decreased with time(glass jar > natural casing under vacuum > aluminum tube > OVTENE). The reduction of PUFA is the consequenceof the increase of peroxides and carbonyls reacting with amino acids to form BAs. This was confirmedby Pearson’s correlation matrices implying that lipid oxidation processes were in some way linkedto the chemical production of BAs
Daphne striata Tratt. and D. mezereum L.: a study of anti-proliferative activity towards human cancer cells and antioxidant properties
No full textIn this study, we investigated for the first time the anti-proliferative
and antioxidant properties of D. mezereum and D. striata. The aerial
parts were extracted by maceration with n-hexane, dichloromethane,
and methanol. MPLC, GC, and GC-MS were used for the phytochemical
study. The anti-proliferative activity was tested against MCF-7, A549,
LNCaP, ACHN, and C32 cancer human cells. The antioxidant activity was
measured by employing β-carotene bleaching, ABTS, DPPH, and FRAP
tests. The Relative Antioxidant Capacity Index (RACI) was applied from
the perspective of statistics. D. mezereum dichloromethane extract
showed a remarkable anti-proliferative with an IC50 of 6.08 μg/mL
against LNCaP cells. Experimental data indicate that Daphne species
have interesting anti-proliferative and antioxidant properties that
deserve more investigations to develop novel antineoplastic drugs
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
Antioxidant and anti-cholinesterase activity of Globularia meridionalis extracts and isolated constituents
No full textThe antioxidant and anti-cholinesterase properties of Globularia meridionalis (Podp.) O. Schwarz (Globulariaceae) were investigated. G. meridionalis aerial parts and roots were extracted with methanol, and the total extract successively partitioned with n-hexane. The methanol fraction of the roots showed the highest antioxidant activity with IC 50 values of 8.0 and 2.1 μg/mL in the DPPH and β-carotene bleaching tests, respectively. From this fraction, three flavonoids, namely pectolinarigenin 7-O-β-glucoside, apigenin 7-O-β-glucoside and luteolin, and two phenylethanoids, namely acteoside and isoacteoside, were isolated. Potential anti-cholinesterase effects were assessed through the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes inhibition assay. The n-hexane fraction of the roots exhibited the highest activity against both AChE and BChE with IC 50 values of 65.5 and 70.4 μg/mL, respectively
In vitro antioxidant and hypoglycemic activities of Ethiopian spice blend Berbere
No full textThe metal chelating activity, antioxidant properties, and the effect on carbohydrate-hydrolyzing enzymes of Ethiopian spice blend Berbere have been investigated. Berbere contains a total amount of phenols corresponding to 71.3 mg chlorogenic acid equivalent per gram of extract and a total flavonoid content of 32.5 mg quercetin equivalent per gram of extract. An increase of the resistance towards forced oxidation was obtained when Berbere was added to sunflower oil. In order to evaluate the bioactivity of the non-polar constituents, an n-hexane extract was obtained from Berbere. The gas chromatography-mass spectrometry analysis revealed the presence of 19 fatty acids constituents (98.1% of the total oil content). Among them, linoleic acid was the major component (72.0% of the total lipids). The ethanolic extract had the highest ferric-reducing ability power (35.4 muM Fe(II)/g) and DPPH scavenging activity with a concentration giving 50% inhibition (IC(50)) value of 34.8 mug/ml. Moreover, this extract exhibited good hypoglycemic activity against alpha-amylase (IC(50) = 78.3 mug/ml). In conclusion, Ethiopian spice blend Berbere showed promising antioxidant and hypoglycemic activity via the inhibition of carbohydrate digestive enzymes. These activities may be of interest from functional point of view and for the revalorization of the spice blend in gastronomy also outside the African country
Extracts of different polarity of Daphne laureola L. as valuable source of antioxidant and neuroprotective compounds
Full text linkIn this study, Daphne laureola L., an European-Mediterranean species, was investigated for its antioxidant properties using different in vitro bioassays, namely 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), Ferric Reducing Activity Power (FRAP), and β-carotene bleaching assays. The acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity using the Ellman’s method was also examined. The aerial parts of D. laureola were subjected to exhaustive and subsequent macerations with solvents at different polarity, such as methanol, dichloromethane, and n-hexane. Dichloromethane extract was the most promising in DPPH and FRAP tests with IC50 values of 32.2 μg/mL and 71.5
μM Fe(II)/g, respectively. Methanol extract showed the most promising inhibition of lipid peroxidation evaluated by β-carotene bleaching test with an IC50 value of 6.6 μg/mL after 30 min of incubation. This extract was the most active against AChE (IC50 value of 56.9 μg/mL). An interesting result was obtained against BChE by the n-hexane extract, with an IC50 value of 49.7 μg/mL. In conclusion, the results suggest that D. laureola may provide a substantial source of phytochemicals, which act as natural antioxidants and acetylcholinesterase inhibitors, and may be beneficial in the treatment of Alzheimer disease
Salvia leriifolia Benth (Lamiaceae) extract demonstrates in vitro antioxidant properties and cholinesterase inhibitory activity
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