130,507 research outputs found
Effect of the diet on the stress response to a simulated transportation experiment of fingerlings of Salmo marmoratus
No full textEffect of feeding system and age on muscle fibre degeneration in two broiler chicken genotypes
No full textTo evaluate how age, genotype (Cobb500 vs. Ross308) and feeding regime (AL: ad libitum; ER: early restricted from 13 to 23 d of age; LR: late restricted from 27 to 37 d; restriction rate: 80% of ad libitum) affected muscle fibre degeneration (MFD) associated to white striping and wooden breast, 144 Pectoralis major from male chickens were sampled at 23, 36, and 48 d of age for histological analyses and scored for MFD level (0=normal, 1=mild, 2=moderate, 3=severe). PROC GLIMMIX of SAS was used to evaluate the effect of main factors and interactions. When age increased, MDF level increased from 1.25 to 1.88 and 2.42 (P<0.001). The feeding regime did not show any effect, but interaction with age tended to be significant (P<0.10): at 23 d, MFD score was 1.28, 1.06, and 1.41 in AL, ER, and LR broilers; at 36 d, the score was 2.14 to 1.92 and 1.58; at 48 d, 2.37, 2.44, and 2.44. Finally, Cobb500 chickens exhibited lower MFD than Ross308 ones (1.67 vs. 2.03; P<0.01). In conclusion, MFD appeared early, increased with age, and changed with genotype; feed restriction lowered MFD only during the restriction period. Further improvements of feeding strategies may contribute to control broiler myopathies
Stress Evaluation Using Physiological Biomarkers on Fish Tested in the Hydraulic Facility
No full textUnderstanding fish’s swimming ability is crucial for assessing their fitness and survival, impacting behaviors, including breeding, interactions between predators and prey, dispersal, and habitat choice. Fatigue curves are commonly used to describe swimming performance, neglecting physiological markers of stress level. This study aims to investigate the use of physiological data to deepen our comprehension of fish swimming performance. Experiments were conducted using a portable flume system in which fish were exposed to two different mean flow velocities (35 and 45 cm/s) until fish stopped swimming or at lower velocities to a maximum exposure time of 1800s. Levels of cortisol, the major stress hormone in fish, and the oxidative damage of lipids and proteins were measured in the muscle tissue of the experimental animals. Fish showed tendential lower stress levels (oxidative stress and cortisol responses) at higher water velocities than lower ones. One biochemical parameter increasingly associated with the metabolic activity is lactate, produced when glucose is consumed under anaerobiosis. In the experiments, lactate levels did not differ between low and high velocities, suggesting that there was no significant difference in the level of physical activity between the fish exposed to low and high water velocities in the flume system. Our article highlights the challenges of studying fish in the wild due to individual variability. Still, it emphasizes the importance of a more comprehensive understanding of fish behavior and physiology in natural environments. Studying fish in the wild is necessary for developing effective management strategies to promote their health and sustainability
The NBT test in various juvenile virus diseases
No full textL'NBT-test in alcune virosi dell'infanzia. Vengono riportati i risultati del test al nitroblu di tetrazolio eseguito in una casistica di bambini affetti da epatite infettiva e varicella. Per quanto concerne i granulociti neutrofili la percentuale di positività non si discosta sensibilmente dai valori ottenuti nei soggetti sani di controllo; una elevata positività si riscontra invece a carico delle cellule mononucleate. Un tale comportamento potrebbe dipendere dal tipo di leucocita interessato nella reazione con l’agente infettante.
Il contributo di A. Faga è consistito nella collaborazione concreta all’attività di laboratorio.
Il lavoro è stato effettuato nell’ambito della collaborazione con l’Istituto di Clinica delle Malattie Infettive di Pavi
Letter: Differential N.B.T. test.
No full textSi espongono i risultati preliminari ottenuti saggiando con il test al nitroblu di tetrazolio granulociti e monociti, nel corso di diverse malattie infettive. La costante positività osservata viene interpretata come espressione delle interazioni fra agenti infettivi e fagociti mononucleati. Il contributo di A. Faga è consistito nella collaborazione concreta all’attività di laboratorio nonché nel reclutamento di pazienti colpiti da infezioni postchirurgiche. Il lavoro è stato effettuato nell’ambito della collaborazione con l’Istituto di Clinica delle Malattie Infettive di Pavi
Muscle cortisol levels, expression of glucocorticoid receptor and oxidative stress markers in the teleost fish argyrosomus regius exposed to transport stress
No full textFish commercial transport is an ordinary practice in the aquaculture industry. This study aimed to investigate the effect of a 48 h transport stress on stress response of meagre (Argyrosomus regius) juveniles. Radioimmunoassay (RIA) and Real-Time PCR were used to evaluate muscle cortisol levels and to assess glucocorticoid receptor (gr) gene expression in fish muscle and liver, respectively. Presence and localization of various oxidative stress markers were investigated in different tissues by immunohistochemistry. A significant increase in muscle cortisol levels was observed after loading but a significant decrease occurred after 16 h from departure even without returning to control levels. Molecular analysis on stress response revealed an increase in muscle gr expression after fish loading that started decreasing during the travel returning to the control level at the end of the transport. Instead, no differences in liver gr expression were observed along the different sampling points. Immunostaining for heat shock protein 70 (HSP70), 4-hydroxy-2-nonenal (HNE), nitrotyrosine (NT) and 8-hydroxy-2’-deoxyguanosine (8-OHdG) antibodies was detected in several organs. Notably, a higher NT immunostaining intensity was evident in skin and gills of the transported animals with respect to controls. Results demonstrated that cortisol and gr are useful indicators of stressful conditions in transported fish
Su un NBT-test differenziale nella diagnostica delle malattie infettive
No full textGli AA. hanno studiato la funzionalità dei fagociti mononucleati e polinucleati mediante l'NBTtest in un gruppo di malattie infettive. Mentre negli individui sani di controllo la positività del test si manteneva inferiore all’8%, nelle condizioni infettive si riscontravano valori superiori all’8%
Glucocorticoids in hair, feces and urine of farmed reproducing European brown hares
No full textIncluded within minor farmed species, hares started to be farmed by ’60s but rearing systems are still not standardized and few information is available on the stress level of animals in captivity. In general, chronically elevated stress levels affect metabolism, immune response, reproduction and/or survival (Boonstra et al., 1998; Sheriff et al., 2009). The present study aimed at measuring corticosterone and cortisol concentrations as stress indicators in hair, feces and urine of farmed reproducing hares in different moment during farming. The pairs were housed in a commercial farm (Venice, Italy),in outside roofed cages (1 m long, 1.60 m wide, 70-80 cm high). Ten pairs at their first reproductive cycle were used: five with dams previously kept in mixed-sex groups and five with dams kept in female groups. Feces, urines and hair of all pairs were collected 1, 7 and 14 days after pair forming, 1 day after partum and after weaning offspring (at 25 d). Feces and urines were collected by a net and a bowl put under the cage 24 hr before sampling while hair was individually collected by gentle pulling hair from the hare back. Corticosterone and cortisol were measured by specific microtitre radioimmunoassays (RIAs) ) as detailed by Bertotto et al. (2011) upon steroid extraction by diethyl ether (urine and hair) or ethanol (faeces). To validate RIAs, parallelism and intra-assay tests were performed. The data were analyzed by PROC MIXED (SAS, 2013) with sex composition of origin group (mixed-sex or only females), sampling time and their interaction as fixed effects. RIA validation tests showed acceptable parallelism for extracts in all matrices and steroids and the intra-assay coefficients of variation were always below 10%. The sex composition of the origin group had no effect on glucocorticoid levels in various matrices, whereas cortisol (124, 29, 37, 86, 39 ng/g at 1, 7, 14 day post pair forming and in post partum and post weaning, respectively; P<0.001) and corticosterone (86, 54, 59, 69, 78 ng/g at 1, 7, 14 day post pair forming and in post partum and post weaning, respectively; P<0.10) concentrations in feces changed with the sampling time. In the present study, both cortisol and corticosterone concentrations were successfully measured in all matrices. Pair forming resulted as the highest stressful time, but the glucocorticoid decrease in feces after 7 d indicates that the stress occurred for a relatively short period. Feces resulted an optimal non invasive matrix for measuring stress in hares, while hair did not both for the lack of differences in glucocorticoid levels and the invasiveness of sampling
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Effect of genotype, gender and feed restriction on growth, meat quality and the occurrence of white striping and wooden breast in broiler chickens
No full textDue to their importance for the control of meat quality in broiler chickens, the present study aimed at identifying the factors associated with the occurrence of myopathies and characterizing the meat properties when affected by myopathies. To this aim, a total of 768 broiler chickens were reared until slaughter (46 d) to evaluate the effect of genotype, gender, and feeding regime (ad libitum vs. restricted rate, 80% from 13 to 21 d of age) on performance and meat quality. Standard broilers were heavier (3,270 vs. 3,139 g; P < 0.001) and showed lower feed conversion (1.56 vs. 1.61; P < 0.001) than the high-yield broilers. Males showed higher final live weight (3,492 vs. 2,845 g) and lower feed conversion (1.54 vs. 1.63) than females (P < 0.001). Feed restriction decreased final live weight (3,194 vs. 3,142 g; P < 0.01) and feed conversion (1.60 vs. 1.57; P < 0.01) compared to ad libitum feeding. At gross examination, feed restriction tended to increase white-striped breasts (69.5 vs. 79.5%; P < 0.10), whereas females showed less wooden breasts than males (8.0 vs. 16.3%; P < 0.05). White-striped fillets had higher pHu (5.87 vs. 5.83), and lower a* (-0.81 vs. -0.59) and b* color indexes (13.7 vs. 14.5) (P < 0.05), whereas wooden breast fillets exhibited higher cooking losses (25.6 vs. 22.1%) and AK-shear force (4.23 vs. 2.84 kg/g) compared with normal fillets (P < 0.001). At histological examination, 3.1% of pectoralis major were normal, 26.6% mildly degenerated, 45.3% moderately degenerated, and 25.0% severely degenerated. In conclusion, genotype had a moderate effect on growth without modifying myopathy occurrence. In contrast, gender and feed restriction affected performance, meat quality, and breast abnormalities
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