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51.
Soil heterotrophic respiration and its temperature sensitivity are affected by various climatic and environmental factors.However,little is known about the combined effects of concurrent climatic and environmental changes,such as climatic warming,changing precipitation regimes,and increasing nitrogen(N)deposition.Therefore,in this study,we investigated the individual and combined effects of warming,wetting,and N addition on soil heterotrophic respiration and temperature sensitivity.We incubated soils collected from a temperate forest in South Korea for 60 d at two temperature levels(15 and 20℃,representing the annual mean temperature of the study site and 5℃warming,respectively),three moisture levels(10%,28%,and 50%water-filled pore space(WFPS),representing dry,moist,and wet conditions,respectively),and two N levels(without N and with N addition equivalent to 50 kg N ha-1year-1).On day 30,soils were distributed across five different temperatures(10,15,20,25,and 30℃)for 24 h to determine short-term changes in temperature sensitivity(Q10,change in respiration with 10℃increase in temperature)of soil heterotrophic respiration.After completing the incubation on day 60,we measured substrate-induced respiration(SIR)by adding six labile substrates to the three types of treatments.Wetting treatment(increase from 28%to 50%WFPS)reduced SIR by 40.8%(3.77 to 2.23μg CO2-C g-1h-1),but warming(increase from 15 to 20℃)and N addition increased SIR by 47.7%(3.77 to 5.57μg CO2-C g-1h-1)and 42.0%(3.77 to 5.35μg CO2-C g-1h-1),respectively.A combination of any two treatments did not affect SIR,but the combination of three treatments reduced SIR by 42.4%(3.70 to 2.20μg CO2-C g-1h-1).Wetting treatment increased Q10by 25.0%(2.4 to 3.0).However,warming and N addition reduced Q10by 37.5%(2.4 to 1.5)and 16.7%(2.4 to 2.0),respectively.Warming coupled with wetting did not significantly change Q10,while warming coupled with N addition reduced Q10by 33.3%(2.4 to 1.6).The combination of three treatments increased Q10by 12.5%(2.4 to 2.7).Our results demonstrated that among the three factors,soil moisture is the most important one controlling SIR and Q10.The results suggest that the effect of warming on SIR and Q10can be modified significantly by rainfall variability and elevated N availability.Therefore,this study emphasizes that concurrent climatic and environmental changes,such as increasing rainfall variability and N deposition,should be considered when predicting changes induced by warming in soil respiration and its temperature sensitivity. 相似文献
52.
Jin Ho CHO Ying Jie CHEN Byung Joon MIN Jong Sang YOO Yuan WANG In Ho KIM 《Animal Science Journal》2008,79(4):453-459
Two experiments were conducted to investigate the effects of reducing dietary crude protein on growth performance, odor gas emission from manure and blood urea nitrogen and IGF-1 concentrations of serum in nursery pigs. In experiment 1, the dietary treatments were (i) CON (CP 19.5%) and (ii) T1 (CP 16.0%). In feces samples, NH3 , H2 S, acetic acid and butyric acid emissions during the T1 treatment were lower than during the CON treatment ( P < 0.05). In feces-urine samples, NH3 emission during the T1 treatment was lower than during the CON treatment ( P < 0.05). In experiment 2, 28 crossbred (Landrace × Yorkshire × Duroc) pigs (13.58 ± 0.10 kg) were used for a 42-day growth trial. Throughout the entire experimental period, ADG and ADFI of the CON treatment were higher than the T1 treatment ( P < 0.05). On day 14, N digestibility in pigs fed the CON diet was higher than that of pigs fed the T1 diet ( P < 0.05). On days 28 and 42, DM digestibility of the CON diet was greater than the T1 treatment ( P < 0.05). On dat 42, serum BUN concentration of pigs fed the CON diet was higher than that of pigs fed the T1 diet ( P < 0.05). In conclusion, these results indicate that reduction in dietary CP concentration decreased NH3 , H2 S and VFA emissions in feces and growth performance in nursery pigs. 相似文献
53.
Summary. Field and glasshouse experiments demonstrated (hat 2,3,5-trichloro-4- pyridinol (pyriclor) at 50–500 g/ha controls Echinochloa crusgalli in direct-seeded rice. It prevented germination and restricted growth of the weed under both static and percolating water conditions, but allowed rice to germinate and grow normally. Pyriclor was most effective when applied early; treated plots gave higher yields than those hand-weeded or sprayed with propanil. Grass weed control was as effective as that given by molinate or nitrofen at much higher rates. Dichlobenil inhibited rice germination, was toxic to young seedlings, and is therefore unsuitable for direct-seeded rice. Molinate had a wider range of latitude in time of application than the other chemicals tested. Glasshouse experiments indicated that pyriclor moves down in percolating water but is adsorbed more readily in fine than in coarse-textured soils. 相似文献
54.
KI‐DONG EOM CHAE‐YOUNG LIM SU‐HYUN GU BYEONG‐TECK KANG YOUNG‐BO KIM DONG‐PYO JANG EUNG‐JE WOO DAEYOUNG KIM ZANG‐HEE CHO HEE‐MYUNG PARK 《Veterinary radiology & ultrasound》2008,49(6):595-599
A Yorkshire terrier and a Chihuahua were referred for acute onset, generalized tonic‐clonic seizures and were suspected to have meningoencephalitis based on magnetic resonance (MR) imaging findings. Brain lesions appeared hyperintense with T2‐weighted imaging and hypointense with T1‐weighted imaging, and were characteristic of necrotizing meningoencephalitis. Both dogs were diagnosed with necrotizing meningoencephalitis based on pathologic findings. Fluorine‐18 fluorodeoxyglucose positron emission tomography (FDG‐PET) was performed on both animals before euthanasia with the permission of the owner. In FDG‐PET images, these lesions seen in MR images were characterized by multifocal or diffuse hypometabolism. Our FDG‐PET results provided evidence of glucose hypometabolism in areas of necrosis and cavitation associated with necrotizing meningoencephalitis. FDG‐PET has the potential to provide valuable diagnostic information in dogs with suspected necrotizing encephalitis. 相似文献
55.
Bottom-up forcing and the decline of Steller sea lions (Eumetopias jubatus) in Alaska: assessing the ocean climate hypothesis 总被引:1,自引:0,他引:1
ANDREW W. TRITES ARTHUR J. MILLER HERBERT D. G. MASCHNER MICHAEL A. ALEXANDER STEVEN J. BOGRAD JOHN A. CALDER ANTONIETTA CAPOTONDI KENNETH O. COYLE EMANUELE DI LORENZO BRUCE P. FINNEY EDWARD J. GREGR CHESTER E. GROSCH STEVEN R. HARE GEORGE L. HUNT JAIME JAHNCKE NANCY B. KACHEL HEY‐JIN KIM CAROL LADD NATHAN J. MANTUA CAREN MARZBAN WIESLAW MASLOWSKI ROY MENDELSSOHN DOUGLAS J. NEILSON STEPHEN R. OKKONEN JAMES E. OVERLAND KATHERINE L. REEDY‐MASCHNER THOMAS C. ROYER FRANKLIN B. SCHWING JULIAN X. L. WANG ARLISS J. WINSHIP 《Fisheries Oceanography》2007,16(1):46-67
Declines of Steller sea lion (Eumetopias jubatus) populations in the Aleutian Islands and Gulf of Alaska could be a consequence of physical oceanographic changes associated with the 1976–77 climate regime shift. Changes in ocean climate are hypothesized to have affected the quantity, quality, and accessibility of prey, which in turn may have affected the rates of birth and death of sea lions. Recent studies of the spatial and temporal variations in the ocean climate system of the North Pacific support this hypothesis. Ocean climate changes appear to have created adaptive opportunities for various species that are preyed upon by Steller sea lions at mid‐trophic levels. The east–west asymmetry of the oceanic response to climate forcing after 1976–77 is consistent with both the temporal aspect (populations decreased after the late 1970s) and the spatial aspect of the decline (western, but not eastern, sea lion populations decreased). These broad‐scale climate variations appear to be modulated by regionally sensitive biogeographic structures along the Aleutian Islands and Gulf of Alaska, which include a transition point from coastal to open‐ocean conditions at Samalga Pass westward along the Aleutian Islands. These transition points delineate distinct clusterings of different combinations of prey species, which are in turn correlated with differential population sizes and trajectories of Steller sea lions. Archaeological records spanning 4000 yr further indicate that sea lion populations have experienced major shifts in abundance in the past. Shifts in ocean climate are the most parsimonious underlying explanation for the broad suite of ecosystem changes that have been observed in the North Pacific Ocean in recent decades. 相似文献
56.
Yuxin YANG Jia GUO JinSoo KIM MyeongHyeon WANG ByungJo CHAE 《Animal Science Journal》2012,83(2):169-177
The objective of this study was to evaluate the effect of different growth rates on carcass characteristics and meat quality and their relationship with myogenesis and lipogenesis in finishing pigs. Pigs were slaughtered at the same age and were assigned to high (HGR) or low (LGR) growth rates with 120 kg or 110 kg final body weights at slaughter. The results indicated that pigs with HGR had heavier (P < 0.05) final body weight, carcass weight, dressing percentage, backfat thickness, higher (P < 0.05) concentrations of fat in the muscle and higher (P < 0.05) total RNA concentration in muscle than pigs with LGR. The messenger RNA (mRNA) expression of lipoprotein lipase, fatty acid synthase, malic enzyme, peroxisome proliferator-activated receptor γ, and sterol regulatory element binding protein-1 in fat were higher (P < 0.05) in pigs with HGR. Additionally, the mRNA expression of glycogen synthase in muscle was lower (P < 0.05) in pigs with HGR. These results indicate differences in postmortem myogenesis and lipogenesis traits of pigs with different growth rates; these differences in turn might have affected carcass characteristics and meat quality. 相似文献
57.
研究了泡桐(原变种)果实的化学成分。采用Sephadex LH-20柱色谱及薄层色谱等方法进行分离.从其70%丙酮提取物水溶性部分分离得到4种苯丙素苷化合物,经波谱分析及理化性质分析,化合物分别鉴定为:毛蕊花苷(1)、异毛蕊花苷(2)、campneosideⅡ(3)和isocampneosideⅡ(4)。化合物1和2首次从该植物中得到。抑菌活性试验结果表明,泡桐(原变种)果实中分离得到的苯丙素苷化合物、丙酮提取物、乙酸乙酯溶及水溶性部分具有较高的抑菌活性,其中,对革兰氏阳性菌中表皮葡萄球菌的抑制能力最强。 相似文献
58.
Ju-Won CHOI Su-Min KIM Jung-Hyun KIM 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(7):1107
A 12-year-old, 3.5-kg, intact female dog was presented with polyuria, polydipsia, and a pendulous abdomen. Laboratory examinations showed elevated hepatobiliary enzyme levels and neutrophilic leukocytosis. The adrenocorticotropic hormone stimulation test confirmed hyperadrenocorticism (HAC). Trilostane therapy managed the clinical condition and cortisol concentration. However, lymphocytosis and nonregenerative anemia developed after HAC remission. Bone marrow aspiration analysis revealed a lymphoproliferative disorder with a clonal T-cell population. Accordingly, the patient was diagnosed with T-cell chronic lymphocytic leukemia (CLL) and concurrent HAC. Thereafter, chemotherapy was initiated, which improved the lymphocytosis. However, euthanasia was performed because of worsening quality of life at 45 weeks after the first presentation. These results suggested that CLL could be masked by excessive endogenous cortisol and discovered after HAC remission. 相似文献
59.
Gyo Moon CHU Jeong Mo YANG Hoi Yun KIM Chung Hui KIM Young Min SONG 《Animal Science Journal》2012,83(1):55-62
This study was conducted to investigate effects of fermented mushroom (Flammulina velutipes) by‐product diets on the growth performance and carcass traits in growing‐fattening Berkshire pigs. The fermented diets mainly contained 40.0% mushroom by‐product, 20.0% formula feed, 26.0% rice bran and supplemental 0.1% probiotics. The mixed ingredients were fermented for 5 days at room temperature. Berkshire pigs (n = 225) were divided into five groups and three replications. The basal diets (C) were substituted by 10% (T1), 30% (T2), 50% (T3) and 70% (T4) fermented mushroom by‐product diets. Crude protein concentration and total calorie in fermented diets were significantly increased (P < 0.05) at the end of fermentation days compared with initial fermentation day. Body weight gain, feed efficiency and carcass weight were significantly lower (P < 0.05) in the T2, T3 and T4 groups than in the control group. Carcass grade was significantly better (P < 0.05) in the pigs fed fermented diets than in the pigs fed control diet and the ratio of high grade (1 plus 2 grades) was higher in the fermented diet groups compared with the control group. Therefore, although a diet of fermented mushroom by‐product decreased growth performance and feed efficiency, it improved the carcass grade in Berkshire pigs. 相似文献
60.
根迹土壤根诱导的化学变化对植物吸收重金属的影响 总被引:4,自引:0,他引:4
It is increasingly recognized that metal bioavailability is a better indicator of the potential for phytoremediation than the total metal concentration in soils; therefore, an understanding of the inffuence of phytoremediation plants on metal dynamics at the soil-root interface is increasingly vital for the successful implementation of this remediation technique. In this study, we investigated the heavy metal and soil solution chemical changes at field moisture, after growth of either Indian mustard (Brassica juncea) or sunffower (Helianthus annuus L.), in long-term contaminated soils and the subsequent metal uptake by the selected plants. In addition, the fractions of free metal ions in soil solution were determined using the Donnan membrane technique. After plant growth soil solution pH increased by 0.2-1.4 units and dissolved organic carbon (DOC) increased by 1-99 mg L-1 in all soils examined. Soluble Cd and Zn decreased after Indian mustard growth in all soils examined, and this was attributed to increases in soil solution pH (by 0.9 units) after plant growth. Concentrations of soluble Cu and Pb decreased in acidic soils but increased in alkaline soils. This discrepancy was likely due to a competitive effect between plant-induced pH and DOC changes on the magnitude of metal solubility. The fractions of free Cd and Zn ranged from 7.2% to 32% and 6.4% to 73%, respectively, and they generally decreased as pH and DOC increased after plant growth. Metal uptake by plants was dependant on the soil solution metal concentration, which was governed by changes in pH and DOC induced by plant exudates, rather than on the total metal concentrations. Although plant uptake also varied with metal and soil types, overall soluble metal concentrations in the rhizosphere were mainly inffuenced by root-induced changes in pH and DOC which subsequently affected the metal uptake by plants. 相似文献