1,721,006 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
Effects of a completely pelleted diet on growing performance of Holstein heifers.
Full text linkForage neutral detergent fiber (NDF) content and
particle size are important factors that affect rumen
function. The aim of the current study was to evaluate
the effects on rumen health, NDF digestibility, and animal
performance of pelleting a forage-based diet. Eight
Holstein heifers (age 336 ± 30 d, body weight 346 ±
35 kg) were randomly assigned to a repeated crossover
design. Animals were housed in tie-stalls and fed for ad
libitum intake. The study included 4 periods of 3 wk,
the first 2 wk for adaptation to the diet and the last
wk for data collection. Diets had the same ingredients
but had a different physical form: total mixed ration
(TMR) and pellet (diameter = 8 mm). The physically
effective NDF (peNDF) differed between the 2 treatments
(39.8 and 11.8% of NDF in the TMR and pellet
diets, respectively). During the trial, dry matter intake
(DMI), water intake, rumination time, rumen temperature,
and pH were evaluated daily. Fecal samples were
collected in wk 3 of each period to determine total-tract
digestibility of the potential digestible (pd)NDF. Average
daily gain and feed conversion ratio were calculated
at the end of each period. With the pellet diet, DMI,
DMI/body weight, and water consumption were higher.
We observed no significant difference in average daily
gain or feed conversion ratio. Rumination time was
lower for the pellet diet than for the TMR diet (241 vs.
507 min/d, respectively). Diet had no effect on rumen
temperature or rumen pH. The total-tract digestibility
of the pdNDF was greater with the TMR diet than
with the pellet diet (90.25 vs. 86.82% pdNDF, respectively).
The results of the current study suggest that
a complete-feed pellet diet was well accepted by the
animals, as demonstrated by higher DMI. Rumination
time was reduced with the pellet diet, but rumen pH
was not different. The pdNDF digestibility was high for
both diets, but significantly higher for the TMR diet.
Given that animal performance was similar between
the 2 diets, although they differed with respect to DMI
and fiber digestion, we hypothesize that the 2 diets
had different retention times, related to their physical
form. A complete-feed pellet diet formulated to provide
a sufficient level of NDF from forages could be fed to
growing ruminants without apparent negative effects
on rumen health and animal productivity, at least for
a short period. More research over a longer growing
period is needed before recommending this feeding
strategy for growing heife
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
pH dynamics and bacterial community composition in the rumen of lactating dairy cows
No full textThe influence of pH dynamics on ruminal bacterial
community composition was studied in 8 ruminally
cannulated Holstein cows fitted with indwelling electrodes
that recorded pH at 10-min intervals over a 54-h
period. Cows were fed a silage-based total mixed ration
supplemented with monensin. Ruminal samples were
collected each day just before feeding and at 3 and 6
h after feeding. Solid and liquid phases were separated
at collection, and extracted DNA was subjected to
PCR amplification followed by automated ribosomal
intergenic spacer analysis (ARISA). Although cows displayed
widely different pH profiles (mean pH = 6.11 to
6.51, diurnal pH range = 0.45 to 1.39), correspondence
analysis of the ARISA profiles revealed that 6 of the 8
cows showed very similar bacterial community compositions.
The 2 cows having substantially different community
compositions had intermediate mean pH values
(6.30 and 6.33) and intermediate diurnal pH ranges
(averaging 0.89 and 0.81 pH units). Fortuitously, these
2 cows alone also displayed milk fat depression, along
with markedly higher ruminal populations of 1 bacterial
operational taxonomic unit (OTU) and reduced
populations of another ARISA amplicon. Cloning and
sequencing of the elevated OTU revealed phylogenetic
similarity to Megasphaera elsdenii, a species reportedly
associated with milk fat depression. The higher
populations of both M. elsdenii and OTU246 in these 2
cows were confirmed using quantitative real-time PCR
(qPCR) with species-specific primers, and the fraction
of total bacterial rDNA copies contributed by these
2 taxa were very highly correlated within individual
cows. By contrast, the fraction of total bacterial rDNA
copies contributed by Streptococcus bovis and genus
Ruminococcus, 2 taxa expected to respond to ruminal
pH, did not differ among cows (mean = <0.01 and
10.6%, respectively, of rRNA gene copies, determined
by qPCR). The data indicate that cows with widely
differing pH profiles can have similar ruminal bacterial
community compositions, and that milk fat depression
can occur at intermediate ruminal pH. The results support
recent reports that milk fat depression is associated
with shifts in bacterial community composition
in rumine and is specifically related to the relative
abundance of Megasphaera elsdenii
Evaluation of fecal sampling time points to estimate apparent nutrient digestibility in lactating Holstein dairy cows
Full text linkINTRODUCTION: The aim of this study was the evaluation of nutrient excretion patterns in samples of feces collected every 2 h to define the best sampling protocol for estimation of apparent digestibility. METHODS: Four multiparous mid-lactation Holstein cows, housed in a tie stall barn and milked twice a day (0800; 1900 h), were enrolled. Dry total mixed ration (TMR) without silages was fed once (0800 h) per day. Feces were sampled every 2 h for 72 h. Each sample was divided in 3 portions: hourly sample sample (8, 10, 12, 14, 16, 18, 20, 22, 00, 2, 4, 6), 8-h composite sample (00–06, 08–14 and 16–22), and a 24-h composite sample. Complete chemical analyses were performed and total tract nutrient digestibility was calculated using undegraded neutral detergent fiber at 240 h of in vitro fermentation (uNDF240h) as a marker. Feeding and rumination patterns were also recorded during the trial. RESULTS AND DISCUSSION: For some parameters, excretion was not constant throughout the day: neutral detergent fiber (aNDFom), undegraded neutral detergent fiber at 24 h of in vitro fermentation (uNDF24h), uDNF240h, total tract crude protein digestibility (TTCPD), total tract neutral detergent fiber digestibility (TTaNDFomD), total tract potentially degraded neutral detergent fiber at 240 h of in vitro fermentation digestibility (TTpdNDF240hD) with minimal values after new TMR delivery and maximal values 12 h after feed delivery. Feeding and ruminating behavior seemed to have an important role in the excretion pattern, due to the pushing and evacuating effect they have. Considering our results, two fecal samples at 12 and 24 h after the TMR delivery are suggested. For one daily sample, 12 h post time of most stable and constant rumination 0000–0600 h, which is also 8 h post feed delivery is suggested
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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