1,721,272 research outputs found
Quantifying morphological stage to predict forage quality of sulla (Hedysarum coronarium L.)
No full textA precise prediction of quality of legumes in the field would enable harvests to be conducted at appropriate nutritive composition levels. Our objective was to predict the nutritive value of sulla (Hedysarum coronarium L.) with the codified morphological stage and weather parameters at two Mediterranean sites (Ancona and Sassari, Italy) in 1996, 1997, and 1998. Herbage samples were collected at progressive morphological stages, from vegetative stage to seed setting. Mean stage by weight (MSW), dry matter yield (DMY), leaf/stem ratio (L/S), crude protein concentration (CP), neutral detergent fiber (NDF), gross energy (GE), and organic matter digestibility (OMD) were determined. Forage characteristics were regressed on growing degree days (GDD) and MSW. The DMY ranged from 2 to more than 10 Mg ha−1 from vegetative to seed set while L/S decreased from almost 5.6 to 0.2 and the CP from a maximum of 295 to a minimum of 107 g kg−1 dry matter (DM). The NDF ranged from 200 to 616 g kg−1 DM and was best predicted by L/S and MSW. The GE was relatively constant across growth stages with a mean value of 18.0 MJ kg−1 DM. The OMD ranged from 398 to 846 g kg−1 organic matter (OM) and declined linearly with increasing MSW. The OMD decreased 32.6 g kg−1 OM per stage unit and followed similar trends for the two sites, with a lower level at the warmer site (Sassari). The MSW was a better predictor of sulla OMD than GDD, with a higher R 2 (0.70 vs. 0.54) and a lower root mean square error
Fat Protein ratio as a tool to monitor dairy cow metabolism
No full textMetabolic disorders and anomalies in ruminal fermentation can affect chemical characteristics of dairy cow milk. Fat to protein ratio (FPR) has been mentioned as a sensitive indicator of metabolic status of dairy cows, and of nutritional imbalances. Some authors indicated as optimal a FPR between 1.2 and 1.4 typical of a positive energy balance, with higher values relating to a metabolic shift towards ketosis, and values below 1.1 probably deriving from rumen acidosis. Moreover, several studies demonstrated the influence of rumen environment on milk fat fatty acid (FA) profile. Some studies showed as a decrease in rumen pH induce a change in the biohydrogenation of unsatured FA resulting in the formation of C18:1trans10 and C18:2trans10 cis-12. Other researchers showed that feeding low fiber diet or inducing acidosis in cows lead to an increase in odd-chain FA from C7:0 to C17:0 including C10:0, C12:0 and C12:1cis9. Additionally, it has been speculated as C18:1trans-10 and the C18:1trans10/C18:1trans11 ratio could be good indicators for the diagnosis of SARA. The aim of the present work was to investigate the difference in milk FA profile between cows with low and normal FPR. The study was carried out on a total of 96 early lactating Italian Holstein dairy cows (60-80 DIM) from 3 different farms, fed total mixed rations typical of the northern Italy. For each farm, the milk of 16 animals with FPR 1 and <1.4 were sampled and analyzed for protein and fat content by infrared spectroscopy and for FA profile by gas-chromatography. Cows with LFPR showed variations in FA concentration typical of subacute acidosis, such as the significant increase of odd chain FA (whose sum increased from 2.49 to 2.72 g/100g; P < 0.01), C10:0, C12:0, C18:1trans10 (0.42 vs 0.59 g/100g; P < 0.01) and the numerical decrease of C18:1trans11, observed by other authors feeding cows acidogenic diets. The same animals showed an increase of the C18:1trans10/C18:1 trans11 ratio found in acidotic cows. Based on these results, it appears that dairy cows showing LFPR are probably facing subacute acidosis–like metabolic variations, probably attributable to specific feeding behavior of these animal, such as sorting, lowering ruminal pH
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
Quantifying morphological stage to improve the organisation of the feeding system and enhance yield and quality of sulla and lucerne
No full textA better knowledge of forage legume production physiology in different environments is
necessary to exploit their potential, through new harvesting and grazing systems. The paper reports the results of
several experiments under different environmental conditions on lucerne (Po Valley) and sulla (Sardinia and
central Italy) with the aim of relating the codified stage to forage quality. The OM digestibility, which is known
to be the most important determinant of the nutritive value of forage, resulted to be inversely related to the stage
evolution of both legumes. The use of the quantified morphological stage proved to be an easy pre-harvest tool
to enhance yield and quality of legumes and to determine cutting or grazing schedules, for a profitable
management of the crop
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
Relazioni tra stadio morfologico di sviluppo, produttività e qualità del foraggio della sulla (Hedysarum coronarium L.) in due ambienti collinari
No full textRelazioni tra stadio morfologico di sviluppo, produttività e qualità del foraggio della sulla in due ambienti collinari
Full text linkSulla is a short-lived Mediterranean perennial legume with remarkable growth in clay and calcareous soils. It is of great
interest for pasture utilisation for its good nutritional value in early stages and bloat-safe characteristics and it may be interesting
for silage conservation due to its high spring yield and sligar content. The aim of this work was to study the evolution of yield and
nutritional characteristics of forage during the first growth cycle and their relationships with the morphological stages in two
environments. The field experiments were set up in Sassari (Sardinia) and Ancona (central Italy). In one year experiment, yield,
DM content, water soluble carbohydrates (WSC), crude protein, NDF, ADF, ADL, andin vitroorganic matter digestibility
(OMD) were determined in the first growth cycle on cultivar Grimaldi in the two environments plus cv. Sparacia in Ancona. The
morphological stage was evaluated and codified with an original scale here proposed based on the Kalu and Fick's scale (1981)
for lucerne. The forage characteristics were regressed on the codified morphological stage and some weather data.The DM content was positively related to the codified stage, and resulted to be particularly low, ranging from 100 to 200
g kg-1, without any difference between cv. and sites (R2adj. = 0.81). The WSC resulted to be dependent on the codified stage, N content in the plant and minimum temperature ofthe day before harvesting (R2adj. = 0.87). The NDF ranged from 300 to 550 g (kg DM)-1and was directly related to growing degree days (DD) and stage. The OMD, which is the most important determinant ofthe nutritive value, was inversely related to the stage and ranged from 758 to 533 g (kg OM)-1as extreme values without difference between cv. in Ancona and in Sassari ranged at a lower level from 714 to 492 g (kg OM)-. Analysing the pooled data of OMD over the sites and cv. the following regression equation was obtained: OMD = -20.7 STAGE -0.111
DD + 830 (R2adj. = 0.90).These relationships indicate the potential usefulness of the numerical codification of the morphological stage adopted for
defining the quality of sulla. The stage, together with DD, resulted to be a promising predictor for the estimation ofOMD of sulla
forage.La sulla, leguminosa mediterranea adatta a suoli argillosi e calcarei, presenta un marcato interesse per l'utilizzo a pascolo
e alcune sue peculiari caratteristiche, tra le quali il buon tenore in carboidrati solubili e l'elevata produttività del taglio
primaverile, potrebbe favorire l'utilizzazione del foraggio per l'insilamento.Lo scopo di questo lavoro è stato quello di studiare l'evoluzione della produzione, delle caratteristiche di insilabilità del
foraggio di sulla in relazione allo stadio morfologico di sviluppo in due ambienti collinari diversi. Da colture di cv. Grimaldi
e Sparacia ad Ancona e cv. Grimaldi a Sassari, nel periodo compreso tra fase vegetativa e allegagione, sono stati raccolti
settimanalmente campioni di foraggio per ciascuno dei quali è stato determinato lo stadio morfologico con un metodo
quantitativo proposto da Kalu e Fick per l'erba medica, adattato per la sulla. Sono stati misurati per ogni rilievo: produzione,
tenore in sostanza secca (s.s.), carboidrati solubili in acqua (CSA), proteina grezza, fibra grezza, NDF, ADF, ADL e digeribilitàin vitrodella sostanza organica (DSO). Le caratteristiche qualitative del foraggio sono state messe in relazione mediante
regressione con lo stadio codificato ed alcune variabili climatiche quali variabili indipendenti.Il contenuto di s.s. è aumentato con l'evolversi dello stadio senza nessuna differenza significativa tra cv. esiti (R2adj. = 0,81). I valori osservati sono particolarmente bassi <130 g (kgS.S.)-1) fino a fioritura. I CSA sono risultati inversamente
correlati con lo stadio codificato, il tenore in N della pianta e la temperatura minima del giorno precedente la raccolta (R2adj. = 0,87). La DSO è risultata inversamente correlata con lo stadio di sviluppo senza differenze fra le cv. ad Ancona, ma ha
evidenziato decrementi settimanali differenti nei due siti, pari a 32 e 37 g (kg S.O.)-1rispettivamente ad Ancona e Sassari.
Dall'analisi di regressione multipla di tutti i dati emerge che il parametro che differenzia la DSO nei due ambienti è la somma
termica (DD), come evidenzia la seguente equazione di regressione unica per cv. esiti:DSO = -20,7 Stadio - 0,111 DD + 830(R2adj. = 0,90).Lo stadio morfologico codificato, assieme alla somma termica, è risultato un parametro fondamentale nello studio
dell'evoluzione della qualità, nonché un promettente predittore per la stima della DSO
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
- …
