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31.
Improving plant water use efficiency (WUE) has the potential to lower plant susceptibility to drought. Amending soils with biochar has been suggested as a way to improve WUE, as it has been shown to increase the water holding capacity of soils. Here, we investigated the influence of two different biochar soil amendments on WUE measured by gas exchange and carbon isotopes of pine-oak ecosystem species. We measured WUE of individuals grown in soils where either lignocellulose or hemicellulose biochar was applied (10% v/v). WUE increased under lignocellulose, but not hemicellulose, biochar amendment during both late spring and early fall measurement periods in a single year study. However, net photosynthesis and stomatal conductance decreased in plants grown with biochar amendments. Physiochemical and sorption data provide a partial explanation of how biochar mechanisms impact soil-water-plant relations. Our results demonstrated that lignocellulosic biochar may be added to forest soils to reduce drought stress in pine-oak systems, but amendments may not lead to increases in carbon uptake rates. 相似文献
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RG Mondadori TR Santin AAG Fidelis EP Porfírio SN Báo 《Reproduction in domestic animals》2010,45(1):33-37
The main objectives of the present study were to determine the ultrastructural modifications occurring in the oocyte during late folliculogenesis and to estimate pre-antral follicle population in buffalo. Half the collected ovaries were fixed and prepared for optic microscopy; the antral follicles from the other ovaries were measured and individually punctured. The cumulus–oocyte complexes (COCs) were processed for transmission electron microscopy. The number of pre-antral follicles in buffalo ovaries was estimated at 19 819 structures. Cumulus–oocyte complexes derived from 1-mm antral follicle had an eccentrical nucleus and compact corona radiata , ooplasm vilosities were fully embedded in zona pellucida (ZP) and a well-defined junction could be observed. Mitochondria were predominantly round and well distributed in ooplasm, as were small lipid vacuoles. In COCs derived from 2-mm antral follicles, the initial formation of perivitelline space was observed. The nucleus was peripherally located and the number of pleomorphic mitochondria increased. Cortical granules were clustered at oocyte periphery and lipid vacuoles increased in number and size. In COCs derived from 6-mm antral follicles, the organelles were located mainly in the perinuclear region. Golgi complexes and smooth endoplasmic reticulum (SER) were more developed. Mitochondria migrated to the cortical region and lipid vacuoles migrated to the medullar region. In COCs derived from 10-mm antral follicles, the lipid vacuoles coalesced and occupied the medullar region of the oocyte, together with a well-developed SER. Mitochondria were pleomorphic and located at the oocyte periphery. In conclusion, the morphological differences described in this paper could be responsible for some functional differences observed in in vitro embryo production and follicular dynamics for buffalo, when compared with cattle. 相似文献
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Growth hormone and prolactin were electrophoretically isolated from amphibian pituitaries and then were tested in a radioimmunoassay with labeled rat growth hormone and antiserum to the same hormone. This isolation and purification of the hormones increased the steepness of the slopes of competitive inhibition in this system when compared to those of crude extracts. Both hormones from most species tested showed high immunochemical cross-reactivity, indicating that amphibian growth hormone and prolactin are structurally related to rat growth hormone. 相似文献
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RG Cashmore TR Harcourt-Brown PM Freeman ND Jeffery N Granger 《Australian veterinary journal》2009,87(1-2):45-50
Three dogs were referred to The Queen's Veterinary School Hospital at University of Cambridge for chronic behavioural or locomotor disorders associated with pain. All three had been unsuccessfully treated with conventional analgesics, including non-steroidal anti-inflammatory drugs, glucocorticoids and opiate agonists, prior to referral, with minimal or no response. They were investigated by neurological examination plus conventional ancillary diagnostic tests and therapeutic drug trials. Ruling out other causes of pain and applying previously well-described criteria, each case was diagnosed as consistent with neuropathic pain, a poorly recognised condition in domestic dogs. Treatment with the tricyclic antidepressant drug, amitriptyline, or the antiepileptic drug, gabapentin, resulted in either a dramatic improvement or full resolution of clinical signs in all cases. 相似文献