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排序方式: 共有337条查询结果,搜索用时 15 毫秒
91.
92.
Ladivania Medeiros do Nascimento Everardo Valadares de Sá Barretto Sampaio Maria Jesus Nogueira Rodal Ana Carolina Borges Lins-e-Silva 《Journal of Forest Research》2014,19(6):501-513
Changes in physiognomy, species composition and structure, and dispersal mechanisms of canopy and subcanopy plant assemblages were investigated along a chronosequence of three ages: 12, 20, and 50+ years old (=old-growth), three replications in each, in an Atlantic Forest landscape in Northeastern Brazil. Our objective was to investigate whether there is floristic and structural convergence along secondary succession. There were significant differences between secondary and old-growth forests in density and basal area only for the subcanopy. Differences in density between forest ages were noted when the assemblage was analyzed per diameter and height classes. Richness of canopy species of both secondary ages differed from those of old-growth forests. Some dominant species in the canopy of secondary forests showed a significant decrease in density with increasing age, which indicates an ongoing process of floristic changes. The low level of shared species between secondary and old-growth forests supports the idea that species composition is one of the last components to recover during successional process. Zoochory was the most important dispersal guild in species percentage and number, irrespective of stand age. Although regenerating areas can take alternative pathways, our results indicate that secondary Atlantic Forest sites have a high potential for natural regeneration. This recovery is recorded as a physiognomic convergence of the canopy layer in as little as 12 years, and progressive introductions of later successional species into the plant assemblage that lead to convergence in terms of the diversity and richness of the subcanopy and of dispersal guilds just 20 years after abandonment. 相似文献
93.
Esterina Fazio Pietro MedicaCristina Cravana DVM PhD Piergiorgio MolinariAdriana Ferlazzo BSc MSc PhD 《Journal of Equine Veterinary Science》2014
Gymkhana is an equestrian event consisting of speed pattern racing and timed games for riders on horses. The aim of the study was to evaluate the effects of gymkhana competition on total cortisol and total and free iodothyronine changes in 23 Arabian purebred horses, by taking into account the effects of previous sport experience on gymkhana riding events. Compared with pre-competition values, an increase of total cortisol concentration has been observed in experienced horses at 30 minutes (P < .001) after exercise and in inexperienced horses both at 5 minutes (P < .05) and at 30 minutes (P < .01) after exercise. Compared with pre-competition values, an increase of total triiodothyronine (T3) concentration has been observed in experienced horses at 5 minutes (P < .05) after exercise. Data obtained showed that gymkhana riding events induced differential adrenocortical and thyroid responsiveness according to previous experience of sport horses. Hence, cortisol and iodothyronine patterns may provide additional information for the monitoring of gymkhana riding performance. 相似文献
94.
JM Baldrighi MF Sá Filho EOS Batista RNVR Lopes JA Visintin PS Baruselli MEOA Assumpção 《Reproduction in domestic animals》2014,49(6):1015-1020
This study was performed to evaluate plasma concentrations of anti‐Mullerian hormone (AMH) and the ovarian antral follicle population (AFP) in different genetic groups. Cyclic heifers (13 Bubalus bubalis [Murrah]; 15 Bos taurus [Holstein] and 10 Bos indicus [Gyr]) were maintained under the same management and were synchronized with two doses of 150 μg IM d‐cloprostenol administered 14 days apart. After the second d‐cloprostenol treatment, heifers had their ovaries scanned daily by ultrasound to define the day of ovulation. On the same day, the AFP was determined and a plasma sample was collected to measure AMH. Murrah heifers had less AFP (25.6 ± 2.1 follicles; p = 0.01) and plasma AMH concentration (0.18 ± 0.03 ng/ml; p < 0.001) than Gyr (60.0 ± 12.2 follicles and 0.60 ± 0.12 ng/ml of AMH); however, data were similar when compared to Holstein (35.9 ± 6.8 follicles and 0.24 ± 0.06 ng/ml of AMH) heifers. Regardless of genetic background, there was a positive relationship between the AFP and plasmatic AMH concentration (Murrah [r = 0.62; p < 0.01], Holstein [r = 0.66; p < 0.001] and Gyr [r = 0.88; p < 0.001]). Also, when heifers were classified according to high‐ or low‐AMH concentration based on the average within each genetic group, high‐AMH heifers had greater (p < 0.0001) AFP than low‐AMH heifers. In conclusion, both Murrah and Holstein heifers presented lower plasma AMH concentration and AFP when compared to Gyr. 相似文献
95.
Valente EM Abou-Sleiman PM Caputo V Muqit MM Harvey K Gispert S Ali Z Del Turco D Bentivoglio AR Healy DG Albanese A Nussbaum R González-Maldonado R Deller T Salvi S Cortelli P Gilks WP Latchman DS Harvey RJ Dallapiccola B Auburger G Wood NW 《Science (New York, N.Y.)》2004,304(5674):1158-1160
Parkinson's disease (PD) is a neurodegenerative disorder characterized by degeneration of dopaminergic neurons in the substantia nigra. We previously mapped a locus for a rare familial form of PD to chromosome 1p36 (PARK6). Here we show that mutations in PINK1 (PTEN-induced kinase 1) are associated with PARK6. We have identified two homozygous mutations affecting the PINK1 kinase domain in three consanguineous PARK6 families: a truncating nonsense mutation and a missense mutation at a highly conserved amino acid. Cell culture studies suggest that PINK1 is mitochondrially located and may exert a protective effect on the cell that is abrogated by the mutations, resulting in increased susceptibility to cellular stress. These data provide a direct molecular link between mitochondria and the pathogenesis of PD. 相似文献
96.
Lee E Marcucci M Daniell L Pypaert M Weisz OA Ochoa GC Farsad K Wenk MR De Camilli P 《Science (New York, N.Y.)》2002,297(5584):1193-1196
In striated muscle, the plasma membrane forms tubular invaginations (transverse tubules or T-tubules) that function in depolarization-contraction coupling. Caveolin-3 and amphiphysin were implicated in their biogenesis. Amphiphysin isoforms have a putative role in membrane deformation at endocytic sites. An isoform of amphiphysin 2 concentrated at T-tubules induced tubular plasma membrane invaginations when expressed in nonmuscle cells. This property required exon 10, a phosphoinositide-binding module. In developing myotubes, amphiphysin 2 and caveolin-3 segregated in tubular and vesicular portions of the T-tubule system, respectively. These findings support a role of the bilayer-deforming properties of amphiphysin at T-tubules and, more generally, a physiological role of amphiphysin in membrane deformation. 相似文献
97.
Nadia Musco Valeria Maria Morittu Vincenzo Mastellone Anna Antonella Spina Giuseppe Vassalotti Biagio D’Aniello Raffaella Tudisco Federico Infascelli Pietro Lombardi 《Journal of animal physiology and animal nutrition》2021,105(Z1):26-33
A nutritional supplement (Ecotrofin™, by Vetoquinol Italia S.r.l) recommended in ruminants feeding to strengthen the physiological condition and improve digestive performance was tested in 20 pluriparae grazing goats divided in two groups (control and treated) to assess its possible effects on milk yield and quality and to assess eventual adverse effects. Animals from both groups also received 400 g/day of corn meal, and the treated group was supplemented with 20 g/head/day of the nutritional supplement. At the doses suggested by the manufacturer, despite a transient increase after 30 days of supplementation, Ecotrofin™ did not show significant effects on milk yield and, although some changes were found in the fatty acids profile, no significant improvement of MUFA and PUFA, as well as of omega-6:omega-3 ratio and CLA content were seen. Therefore, in our experimental conditions the supplementation of diet with Ecotrofin™ did not appear useful to improve goat's performance. A significant effect on kidney health markers (27 vs. 22.5 for urea and 0.83 vs. 0.76 for creatinine, p < 0.05) suggested a beneficial effect on renal function but, since levels fell in the normal ranges in both groups, such hypothesis would need further studies to be addressed. 相似文献
98.
Renan B. Paiano Jeannine Bonilla Andrea M. Moreno Pietro S. Baruselli 《Reproduction in domestic animals》2021,56(12):1536-1542
The aim of this study was to identify the impact of Trueperella pyogenes in cows with clinical endometritis (CE) on reproductive performance and milk production in affected cows. In total, 230 lactating Holstein dairy cows from six commercial dairy herds were sampled once between 28 and 33 days post-partum. Cows included in the present study did not receive antibiotic or anti-inflammatory treatments prior to the experimental period. Clinical endometritis (CE) was characterized as cow with vaginal mucus score = 3 (>50% of purulent vaginal discharge) and >18% polymorphonuclear neutrophilic leukocyte (PMNL). The body condition scores (BCS) and milk production were evaluated at the time of enrolment. The identification of isolated bacteria was carried out through the analysis of MALDI-TOF MS (matrix-assisted laser desorption ionization time-of-flight mass spectrometry). According to uterine health, three groups of dairy cows were formed: healthy control cows without T. pyogenes (n = 147), CE cows with T. pyogenes (n = 22) and CE cows without T. pyogenes (n = 61). CE cows with T. pyogenes had lower BCS, milk production and conception at first AI (p < .01) than CE cows without T. pyogenes and control cows. Furthermore, CE cows with T. pyogenes had higher (p < .01) service per pregnancy and had greater (p < .01) days to get pregnant than CE cows without T. pyogenes and control cows. This study demonstrates that CE cows with T. pyogenes had impaired reproductive performance and milk production when compared to cows without CE and CE cows without T. pyogenes. This information can contribute to a strategic treatment in cows affected by clinical endometritis, favouring the rational use of antibiotics on dairy farms. 相似文献
99.
Enrico Bottero Emanuele Mussi Fabiano Raponi Davide De Lorenzi Pietro Ruggiero 《The Canadian veterinary journal. La revue veterinaire canadienne》2021,62(7):736
This study describes the clinical, diagnostic, and pathological characteristics of canine nasal polyps and how they responded to medical, endoscopic, and surgical treatments. The database of a multi-center veterinary endoscopy group was searched from 2010 to 2018. All dogs with a histological diagnosis of nasal polyposis that were undergoing endoscopic investigation (N = 23), were included. Clinical signs at presentation were sneezing (91%), nasal discharge (83%), stertor (74%), and frontonasal deformation (17%). Skull radiography on 13 dogs had alterations in 77% of cases, including turbinate lysis (6/13), increased radiopacity of one (4/13) or both (6/13) nasal cavities, and lysis of the nasal vomer bone (3/13). Nasal polyposis had a characteristic endoscopic appearance. There were clinical and diagnostic similarities between this cohort of dogs and dogs with nasal neoplasia, although dogs with nasal polyps were often younger and polypoid tissue was external to the nose. Steroid therapy alone was not effective in treating polyposis in dogs; however, endoscopic debulking with a laser and forceps was more effective. 相似文献
100.
Stefania Colombini Andrea Rota Graziosi Pietro Parma Marcello Iriti Sara Vitalini Chiara Sarnataro Mauro Spanghero 《动物营养(英文)》2021,7(1):224
This study investigated the effects of 2 Achillea moschata essential oils extracted from plants collected in 2 different valleys of the Italian Alps and 3 pure compounds of oils — bornyl acetate (BOR), camphor (CAM), and eucalyptol (EUCA) — on in vitro ruminal fermentation and microbiota. An in vitro batch fermentation experiment (Exp. 1) tested the addition of all of the substances (2 essential oils and 3 compounds) in fermentation bottles (120 mL) at 48 h of incubation, whereas a subsequent in vitro continuous culture experiment (Exp. 2) evaluated the pure compounds added to the fermenters (2 L) for a longer incubation period (9 d). In both experiments, total mixed rations were incubated with the additives, and samples without additives were included as the control (CTR). Each treatment was tested in duplicate and was repeated in 3 and 2 fermentation runs in Exp. 1 and 2, respectively. Gas production (GP) in Exp. 1 was similar for all of the treatments, and short chain volatile fatty acid (SCFA) production was similar in both experiments except for a decrease of SCFA produced (P = 0.029) due to EUCA addition in Exp. 2. Compared to CTR, BOR and CAM reduced the valerate proportion (P = 0.04) in Exp. 1, and increased (P < 0.01) the acetate proportion in Exp. 2. All treatments increased (P < 0.01) total protozoa counts (+36.7% and +48.4% compared to CTR on average for Exp. 1 and 2, respectively). In Exp. 1, all of the treatments lowered the Bacteroidetes and Firmicutes and increased the Proteobacteria relative abundances (P < 0.05), whereas in Exp. 2, the EUCA addition increased (P = 0.012) the Ruminococcus. In Exp. 1, methane (CH4) as a proportion of the GP was lowered (P = 0.004) by the addition of CAM and EUCA compared to CTR, whereas in Exp. 2, EUCA reduced the amount of stoichiometrically calculated CH4 compared to CTR. Overall, essential oils extracted from A. moschata and the pure compounds did not depress in vitro rumen fermentation, except for EUCA in Exp. 2. In both experiments, an increase of the protozoal population occurred for all the additives. 相似文献