322,866 research outputs found
The control of reproduction in finfish species through GnRH treatments
No full textFish in captivity can show some dysfunctions, at different levels, in the physiological processes of reproduction, due to
the lack of synthesis or release of gonadotropins (GtHs) by hypophysis. As a consequence, a worsening of quality and
quantity of spawned gametes, or a lack of egg and sperm spawning, can be observed. The farmers can act on fish reproductive
cycle manipulating the environmental parameters of rearing, the diet, the genetics or using GnRH treatments.
Nowadays, they are used mainly GnRH, synthesized in laboratory as analogues. These releasing factors, naturally produced
by hypothalamus, let to overcome the technological and biological limits of the “traditional” hormonal treatments
with hCG, being more effective, cheaper and easily available on market. This article makes a historical survey of the conditioning
treatments for fish reproduction and also considers the future perspectives of these treatments, examining the
topics that research will have to focus, in order to make these treatments common worldwide, in any hatchery and for
each farmed species of finfish
Száll és ég s kihuny a csillag : Versek, naplórészletek
No full textJan Rainis ; [vál. és az utószót írta Saulcerite Viese
Comparative study on milt quality features od different finfish species
No full textThe aim of this research was to study the main sperm characteristics of three different finfish species. Twenty-one gilthead
sea bream (Sparus aurata), 20 brown trout (Salmo trutta, morpha fario) and 15 rainbow trout (Oncorhynchus
mykiss) male broodstocks, farmed under optimal conditions for each species and fed standard diets for broodstocks, were
manually stripped. Brown trout yielded small amounts of sperm (4.5 vs 18.13 ml) that were very concentrated (≅ 8.5 x
109 vs 1.24 x 109 Szoa/ml) with respect to the other species. The duration of spermatozoan motility for gilthead sea
bream sperm was significantly longer (almost 50 min), in comparison to the one-minute motility of Salmonids. Single
fatty acids of brown trout sperm were higher than in the other two species for almost all detected fatty acids. In particular,
eicosapentaenoic acid (EPA) was at least three times more concentrated in brown trout than in rainbow trout or gilthead
sea bream sperm (1238.3 μg/g vs 305.6 and 333.3 μg/g, respectively; P < 0.01). Saturated, polyunsaturated and
total unsaturated fatty acid classes were significantly higher in brown trout sperm than in the other two species - almost
double with respect to gilthead sea bream sperm and more than double in comparison to RT sperm (P < 0.01)
Effects of vitamin E and phosphatidylcholine on qualitative and quantitative parameters of rainbow trout (Oncorhynchus mykiss) milt
No full textThe aim of this work was to investigate the effects of vitamin E and phosphatidylcholine on rainbow trout
(Oncorhynchus mykiss) milt. One hundred and twelve rainbow trout (RB) broodstock (2n, 1030± 20g
body weight, male:female ratio = 50:50) were fed four isoproteic and isolipidic diets for 110 days. Diets
were differing for the type of vitamin premix and phosphatidylcholine supplied: Control (vitamin premix
without Vit. E, no phosphatidylcholine); Vit.E (a premix with Vit. E, no phosphatidylcholine); PhC, (vitamin
premix without Vit. E, phosphatidylcholine 2.5%); Vit.E +PhC, (vitamin premix with Vit. E and phosphatidylcholine
2.5%).
Sperm total volume, in sexually mature males (3+; 966±114g body weight), ranged between 18.57ml
(Control) and 34.31ml (Vit. E). Sperm density varied between 1.76x109 Szoa/ml (Control) and 1.16x109
Szoa/ml (Vit. E+PhC), while relative density (related to male body weight) tended to increase with Vit. E
(>50x109 Szoa/ml) and to reduce with Vit. E + PhC (85%
in all treatments, while motility duration was around 2.37min for Vit. E and Control reached only 0.97min.
After overnight storage (+4°C, for 18 hours) motility decreased, 75-80% in gamete motility and 3.39-
56.7% in time motility.
PhC dietary supplements significantly increased arachidonic acid contents of sperm with respect to
Control (>120 vs 73μg/ g), while Vit. E caused a huge increase in C20:3 n-3 (10.25 vs 2.27ppm).
DHA/EPA ratio was significantly lower in Control (>2; p<0.05), while n-3/n-6 ratio was significantly the
highest for Vit. E (9.46 vs <7.3)
The effect of dietary coconut oil on reproductive traits and egg fatty acid composition in rainbow trout (Oncorhynchus mykiss)
No full textTwo hundred and twenty rainbow trouts (IBW: 700 g) were randomly allotted to four tanks,
with a male/female ratio of 0.56. Fish were fed for 168 d with four experimental diets containing herring
oil, cod liver oil and coconut oil with the following inclusion rates: diet A: 12-1-0% respectively;
diet B: 6-1-6%; diet C: 0-1-12%; diet D: 0-0-13%. Irrespective of the dietary treatment, weight gains of
broodstocks were high (> 3 g/d) and FCR below 2. No significant difference was observed concerning
the total amount of eggs spawn, egg average weight (82.5 mg/egg) and lipid content (5.4 mg/egg).
However, the fatty acid profile of eggs was significantly affected by the dietary treatments. The content
of unsaturated fatty acids, particularly the n-3 fatty acid series (EPA and DHA) significantly decreased
with increasing levels of coconut oil in the diet
S-Puškin! Ovvero: Tre traduzioni. Evgenij Onegin a teatro, in fumetto e par furlan
No full textPuškin, “il nostro tutto” secondo l’antologico adagio di Grigor’ev, è una pre-
senza sempre viva nella cultura russa contemporanea: così il suo capolavoro
Evgenij Onegin, che viene ‘riscritto’ nelle opere di drammaturghi russi contemporanei – o assume la veste (grafica) di un manga e di un romanzo a fumetti.
Nuove traduzioni – intralinguistiche e intersemiotiche – di un testo ritenuto
intraducibile, eppure tradotto (e ritradotto) in tutte le maggiori lingue nazionali. Da oggi, in massima provocazione, anche in una lingua ‘minore’: il friulano. L’articolo – trascrizione di fatti realmente accaduti (a una conferenza che non si vuole definire tale) – esplora i confini del tradurre, aprendo brecce di senso e di sensi su un’opera che per il lettore straniero ha sempre avuto il gusto indecifrabile e dubbio – come suggeriva Nabokov – dello “Champagne sovietico”
. The effects of coconut oil on reproductive traits and fatty acid eggcomposition of rainbow Oncorhynchus mykiss, Walbaum)
No full textTwo hundred and twenty rainbow trouts (IBW: 700 g) were randomly allotted to four tanks,
with a male/female ratio of 0.56. Fish were fed for 168 d with four experimental diets containing herring
oil, cod liver oil and coconut oil with the following inclusion rates: diet A: 12-1-0% respectively;
diet B: 6-1-6%; diet C: 0-1-12%; diet D: 0-0-13%. Irrespective of the dietary treatment, weight gains of
broodstocks were high (> 3 g/d) and FCR below 2. No significant difference was observed concerning
the total amount of eggs spawn, egg average weight (82.5 mg/egg) and lipid content (5.4 mg/egg).
However, the fatty acid profile of eggs was significantly affected by the dietary treatments. The content
of unsaturated fatty acids, particularly the n-3 fatty acid series (EPA and DHA) significantly decreased
with increasing levels of coconut oil in the diet
Re-learning process in dairy cows pastured with virtual fencing system
No full textThe Virtual Fencing (VF) system is an innovative technology for animals on pastures. In a VF system, physical boundaries are replaced by virtual ones, and the containment of animals is ensured by the delivery of two deterrent stimuli: an acoustic warning followed by an electrical pulse, if the animal continues to move away from the virtual boundary. It has been shown that animals learn the system within 2 to 4 days. However, it is unclear whether they can retain this learning after a period of non-use. A group of 12 lactating dairy cows were managed with VF collars (Nofence®) on a lowland pasture for a 6-day learning period, during which virtual boundaries were changed daily. The animals were then moved to a mountain pasture grazing for 3 months without using VF. This was followed by a VF re-learning period of 6 days. The study aimed to evaluate the retention of the learning capacity of the animals by assessing the differences in the emission of the acoustic warnings and electric pulses between two periods (learning vs. re-learning). The data were analysed using generalized mixed-effects models. The results showed that the total number of electric pulses was significantly higher during the learning period respect to re-learning period, with a high probability of receiving an electric pulses during the days. In conclusion, the results demonstrated that animals have the ability to retain learning after a period of non-use, confirming the flexibility in the use of the VF
Diffusive author(s), cohesive author: Analysis of S/N (1994)
No full textThis study indicates the ways in which various aspects of the author(s) are brought forth in Dumb type’s performance art, the S/N production. Previous research has suggested a non-hierarchical organization of Dumb type and the absence of a “privileged author” in Dumb type’s collaborative work, S/N. However, the results that I have investigated from member’s interviews on the creative process of S/N along with my analysis of the recorded images of S/N, indicate a different aspect of the author(s). First, S/N was created through, so to speak, the collective ideas of the members of Dumb type. Further, S/N has at least nine quotations from previous performances, installations, and printed writings, besides the work-in-progress technique. Explicating one of the “author functions” as given by Michel Foucault, each text has plural subjects of the author. However, it has been revealed from members’ interviews that Teiji Furuhashi had a decision-making role in selecting the members’ ideas within the performance. Since then, S/N has had plural subjects of creation; however, Furuhashi is one of the subjects of creation along with the “privileged author.” S/N has plural authors (diffusive authors) yet at the same time, it has a “privileged author,” Teiji Furuhashi (cohesive author)
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
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