Arterial oxygen tension and pulmonary ventilation in horses placed in the Anderson Sling suspension system after a period of lateral recumbency and anaesthetised with constant rate infusions of romifidine and ketamine     

I. François  F.‐X. Lalèyê  M. Micat  K. Benredouane  K. Portier 《Equine veterinary journal》2014,46(5):596-600

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Comparative digestibility of low‐quality grass hay by two breeds of cattle differing in mature live weight     

A. L. Lourenço  A. Dias‐da‐Silva  A. S. Santos  M. A. M. Rodrigues  J. W. Cone  L. M. M. Ferreira 《Journal of animal physiology and animal nutrition》2014,98(3):453-457

The digestive capacity of the Portuguese native breed of Barrosão cattle and the Holstein–Friesian breed was measured when fed meadow hay (72–74 g CP and 641–671 g NDF/kg dry matter), offered either alone or supplemented with soya bean meal (150 g/kg dry matter), at maintenance level. Four mature cows of each breed were used. Average initial live weight (LW) was 457 and 635 kg for the Barrosão and the Holstein–Friesian cows respectively. The organic matter digestibility (OMD) of the meadow hay was higher in Holstein–Friesian than in Barrosão cows (p < 0.08) whether supplemented or not. The neutral detergent fibre digestibility of the hay was also higher in Holstein–Frisian when the hay was fed alone (p < 0.08). The soya bean meal supplementation increased the OMD and the NDFD digestibility of the total diet (p < 0.05), but not the OMD digestibility of the hay (p > 0.05). The results obtained in this study suggest a higher ability to digest fibre in the large dairy breed than in the small native breed. This suggestion is also supported by previous findings with sheep breeds largely differing in mature live weight.  相似文献   

European oak powdery mildew: impact on trees,effects of environmental factors,and potential effects of climate change     

Benoit Marçais  Marie-Laure Desprez-Loustau 《Annals of Forest Science》2014,71(6):633-642

? Context

Powdery mildew is one of the most common diseases of oaks in Europe. After alarming reports in the beginning of the twentieth century following the presumed introduction of the invasive fungus, the disease has become familiar to foresters. However, its impact may vary greatly according to intrinsic and extrinsic factors.

? Aims

We aimed at providing updated and synthesised information on the impact of powdery mildew on oak and on the effects of environment on disease.

? Methods

A comprehensive literature review was performed, including old reports of the early epidemics to more recent data.

? Results

Tree growth patterns are of critical importance to explain the severity of the disease and the differences between juvenile and mature trees. A critical element, especially for infection of mature trees, is the availability of spores during the production of the first leaf flush. High disease impact is often related to modified growth patterns, either by environmental factors (insects or frost) or silvicultural practices (e.g., coppicing).

? Conclusion

Powdery mildew can have important impacts in natural oak regenerations and a significant role in decline of mature trees. Climate change might influence the disease severity mainly by altering the host pathogen phenological synchrony. Process-based models are required for reliable predictions.  相似文献   

Oak powdery mildew changes growth patterns in its host tree: host tolerance response and potential manipulation of host physiology by the parasite     

Marie-Laure Desprez-Loustau  Gilles Saint-Jean  Benoît Barrès  Cécile Françoise Dantec  Cyril Dutech 《Annals of Forest Science》2014,71(5):563-573

Context

Parasites can induce strong effects on their host’s growth, not only as a result of host resource exploitation (growth loss) but also with a potential adaptive value for host (tolerance response) and themselves (increased transmission).

Aims

We assessed these three types of phenotypic changes in oak seedlings infected by powdery mildew.

Methods

A manipulative field experiment with three levels of parasite inoculum was designed in order to tease apart infection from genetic effects on oak growth. Seedlings were monitored during 3 years for height growth, phenology and infection.

Results

Powdery mildew infection induced both significant growth loss and qualitative changes in plant architecture. The most striking and unexpected change was increased growth polycyclism in infected seedlings. This benefitted both the host as a form of compensation for infection-caused height loss, and the pathogen, by increasing sporulation.

Conclusion

The study highlights the effect of parasites in the expression of plant phenotypic traits, such as phenology and ultimately tree architecture. Both host tolerance and parasitic manipulation may be involved in the observed changes in growth patterns. These results suggest a complex interplay between development and defence in trees and emphasize the need to better assess tolerance mechanisms when considering the defence strategies of trees against pathogens.  相似文献   

Ion levels in the gastrointestinal tract content and plasma of four teleosts with different feeding habits     

A.G. Becker  J.F. Gonçalves  L.O. Garcia  E.R. Behr  F.J.K. Mallmann  D.L. Graça  B. Baldisserotto 《Fish physiology and biochemistry》2006,32(2):105-112

The levels of various ions (Na⁺, Cl⁻, Ca²⁺, Mg²⁺, K⁺) in the fluid phase of the gastrointestinal contents and of the plasma were determined in four teleosts with different feeding habits: traira (Hoplias malabaricus), hassar (Hoplosternum littorale), silver catfish (Rhamdia quelen), and grass carp (Ctenopharyngodon idella). The results showed that most ionic levels in the fluid phase of the gastrointestinal tract seem to be affected by feeding habit and that these levels can be different from those found in the plasma. In practical terms, these results suggest that ionic levels of the gastrointestinal contents should be considered when preparing solutions for studies of intestinal absorption in fishes.  相似文献   

Spermatogenesis in teleost: insights from the Nile tilapia (Oreochromis niloticus) model     

D.A.R. Vilela  S.G.B. Silva  M.T.D. Peixoto  H.P. Godinho  L.R. França 《Fish physiology and biochemistry》2003,28(1-4):187-190

The morphometric study of spermatogenic cysts in sexually mature tilapias, during the evolution of spermatogenesis, showed a dramatic increase in both number of germ cells and cyst volume. However, the opposite trend was observed for germ cell size. Nevertheless, the number of Sertoli cells increased gradually up to leptotene/zygotene cysts, stabilizing thereafter. Based on the number of spermatids supported by each Sertoli cell and compared to mammals, Sertoli cell efficiency in tilapias is remarkably high. Sertoli cell proliferation was frequently observed, mainly in spermatogonial cysts, and probably is the major factor related to the testis growth and the increase in sperm production that normally occurs in adult tilapias. The combined duration of spermatocytes (5 days) and spermiogenic (5–6 days) phases of spermatogenesis in fish kept at 25 °C was 10–11 days. Mainly due to acceleration in meiosis, these two phases lasted a total of 6 days in tilapias kept at 30 °C, in the opposite way, at 20 °C spermatogenesis was arrested at pachytene spermatocytes. To our knowledge, this is the most comprehensive investigation performed up to date on testis morphometry and function in adult tilapias.  相似文献   

The evaluation of secondary stress response of grass carp (Ctenopharyngodon idella, Val. 1844) after exposing to the saline water     

H. Yavuzcan-Yıldız  M. Kırkavgaç-Uzbilek 《Fish physiology and biochemistry》2001,25(4):287-290

The stress response of grass carp to salinity was evaluated assessing the levels of hematocrit, leucocrit, plasma glucose, sodium, potassium and calcium. Mean hematocrit values increased following exposure to salinity. Mean leucocrit values elevated after exposure to salinity for 24 h, then decreased. Mean plasma glucose increased during saline exposure for 48 h and then decreased to normal values. Plasma sodium and chloride levels were increased to their highest values after 48 h. While plasma potassium value increased with the exposure time, plasma calcium values were not affected by salinity exposure.  相似文献   

Selective control of polyamide dyeing with acid dyes using hydroxypropyl-β-cyclodextrin     

Jorge G. Santos  Teresa Miranda  Graça M. B. Soares 《Fibers and Polymers》2014,15(4):788-793

The effect of hydroxypropyl-β-cyclodextrin (HPβCD) in the dyeing of polyamide fabric was investigated under conditions that mimic industrial dyebaths where dye mixtures are used. The dyes used were Telon Red BN, Telon Yellow A-2R, and Telon Blue RR. The blue dye complexed with HPβCD whereas the other dyes did not do so under the conditions used. The dyeing results were compared with those obtained using a traditional retarding agent, Albegal B. The exhaustion dyeing data showed that HPβCD mainly affected the dyeing behavior of the blue dye that became encapsulated. In the case of the yellow and red dyes, changes in the overall kinetics of dyeing were observed, resulting in modified exhaustion profiles. In comparison, Albegal B retarded the blue dyeing process and increased the rate of exhaustion of the yellow dye while the exhaustion curve of red dye remained unchanged. The color uniformity of the dyed polyamide was improved when HPβCD was used. This resulted from the more controlled exhaustion rate during the critical phase of the dyeing process.  相似文献   

Estimation of the area-specific suspended sediment yield from discrete samples in different regions of Belgium     

Van Campenhout  Jean  Petit  François  Peeters  Alexandre  Houbrechts  Geoffrey 《Journal of Soils and Sediments》2022,22(2):704-729

Journal of Soils and Sediments - Suspended sediment transport, which represents the majority of the sediment load, has been studied across very different scales and in a wide variety of regions and...  相似文献   

Determining home range,changes in habitat use with time,and the threats to an endangered freshwater turtle (Rafetus euphraticus) in Turkey     

Yusuf Bayrakcı  Dinçer Ayaz  Luca Luiselli 《水产资源保护:海洋与淡水生态系统》2021,31(11):3276-3290

1. The Euphrates softshell turtle (Rafetus euphraticus) is the most threatened chelonian species in the Middle East, where it is endemic to the Tigris and Euphrates basins. Since the ecology of this species is little known, it is difficult to plan any reliable action for its correct management and conservation.
2. To enhance the scientific knowledge on R. euphraticus, and to establish a science-based management strategy, a detailed investigation was undertaken on the distribution, habitat, activity and home range of R. euphraticus in Turkey. The previous distribution records in Turkey are for the 1990s; thus, this study is the first comprehensive field research on the species after nearly 3 decades.
3. There was a significant sexual size dimorphism in the Turkish population, with males larger than females.
4. Four individuals were radiotracked for 1 year. The mean home range was highly variable depending on how it was calculated, but that of males was considerably greater than that of females by all methods used.
5. A quantitative evaluation was made of habitat change with time. The land cover classes potentially available to turtles in the Euphrates River basin increased by more than 100% between the 1990s and 2018: 92% of this enhancement was derived from water bodies and coastal lands.
6. Fifteen dams have been built in the lower part of the basins in the last 30 years. In addition, continuing human interactions have caused the fragmentation or destruction of suitable habitats for R. euphraticus.
7. The factors threatening R. euphraticus were assessed and a conservation action plan was developed. Some objectives such as monitoring and creating awareness of this action plan have been met while others are still waiting to be achieved.

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