Methanotrophs are favored under hypoxia in ammonium-fertilized soils     

A.?WalkiewiczEmail authorView author&#;s OrcID profile  M.?Brzezińska  A.?Bieganowski 《Biology and Fertility of Soils》2018,54(7):861-870

Methanotrophy of arable soils is affected by N fertilization, but the knowledge about the effect of oxygen level is poorly understood; soil aeration can fluctuate and zones of low oxygen are widespread in soil. We monitored CH₄ oxidation in three mineral soils (Eutric Cambisol, Haplic Podzol, Mollic Gleysol) under laboratory conditions by varying the O₂ level (from 20 to 2% O₂), with or without NH₄⁺ (100 mg N kg^?1). In controls (without NH₄⁺), CH₄ was oxidized completely in the O₂ range from oxia (20% O₂) to high hypoxia (5% O₂), while the process was inhibited under microoxia (2% O₂). Ammonium application decreased CH₄ consumption in all soils. This negative effect was stronger at 20% and 2% O₂ than under hypoxia. The highest CH₄ oxidation rates and the shortest initial (lag) phases in both control and NH₄⁺-amended soils were observed under high (5% O₂) and low (10% O₂) hypoxia.  相似文献   

Peroral Application of Water-soluble Derivative of Propolis (WSDP) and Its Related Polyphenolic Compounds and Their Influence on Immunological and Antitumour Activity   总被引：2，自引：0，他引：2  

Orsolic N  Sver L  Terzić S  Basić I 《Veterinary research communications》2005,29(7):575-593

Polyphenolic compounds are widely distributed in the plant kingdom and display a variety of biological activities, including chemoprevention and growth inhibition of tumours. Propolis contains a conglomerate of polyphenolic compounds. We investigated the effect of propolis and polyphenolic compounds, components of propolis, on the growth and metastatic potential of a transplantable mammary carcinoma (MCa) of the mouse. Metastases in the lung were generated by 2 x 10 tumour cells injected intravenously (i.v.). A water-soluble derivative of propolis (WSDP) and the polyphenolic compounds (caffeic acid (CA) and caffeic acid phenethyl ester (CAPE)) were given to mice perorally before or after tumour cell inoculation. WSDP, CA and CAPE reduced the number of metastases in the lung. This implies that the antitumour activities of the compounds used in these studies are mostly related to the immunomodulatory properties of the compounds, their cytotoxicity to tumour cells, and their ability to induce apoptosis and/or necrosis.  相似文献   

Immunohistochemical detection of ophidian paramyxovirus in snakes in the Canary Islands     

Orós J  Sicilia J  Torrent A  Castro P  Déniz S  Arencibia A  Jacobson ER  Homer BL 《The Veterinary record》2001,149(1):21-23

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Multicentric lymphoblastic lymphoma in a loggerhead sea turtle (Caretta caretta)     

Orós J  Torrent A  Espinosa de los Monteros A  Calabuig P  Déniz S  Tucker S  Jacobson ER 《Veterinary pathology》2001,38(4):464-467

A juvenile female loggerhead sea turtle (Caretta caretta) stranded in Gran Canaria was submitted for necropsy. The turtle had exhibited anorexia and lethargy for 2 weeks prior to its death. At necropsy, the thymus was enlarged by two white and firm nodules. White nodules similar to those in thymus were observed in the plastron, thyroid gland, heart, aorta, left lung, spleen, liver, kidneys, stomach, and small intestine. Histopathology revealed a neoplastic proliferation of round cells identified as lymphoid cells. Ultrastructurally, the neoplastic cells were consistent with lymphoblastic cells, and viruses were not detected. The diagnosis was multicentric lymphoblastic lymphoma. This is the first report of a lymphoid neoplasm in a sea turtle.  相似文献   

Oak restoration in water-limited pine plantations: interactive effects of overstory light interception and water availability on understory oak performance     

Arnon Cooper  Or Shapira  Sohil Zaidan  Yosi Moshe  Ela Zangy  Yagil Osem 《European Journal of Forest Research》2014,133(4):661-670

Oak regeneration within pine monocultures is an opportunity to diversify forest structure. We examined the relationships between overstory (Pinus brutia) light interception and understory oak (Quercus ithaburensis) performance in water-limited forests. The study was performed in a mature pine plantation in Mediterranean Israel. Twenty-year-old oaks differing in location with respect to pine overstory and representing a gradient of light availability, such as open space (irradiance 100 %), interface (17–77 %), and understory (14–23 %), were monitored. Photosynthetic photon flux density (PPFD), leaf gas exchange, and twig water potential (TWP) were measured during the growth season under increasing drought stress. Predawn TWP decreased sharply from early to late spring and was positively related to irradiance during mid-spring only. Predawn to midday TWP gradient was positively related to irradiance mostly so during mid-spring. Daily averages of stomatal conductance (gs), net carbon assimilation rate (A), and transpiration rate (E) were highest in early spring and decreased gradually toward late spring. They were positively related to irradiance though this relationship became less pronounced from early to late spring. Oak height and stem basal area were positively related to irradiance. A/gs ratio was positively related to irradiance throughout the entire growth season. It increased from early to mid-spring but decreased toward late spring. A/PPFD ratio decreased from early to late spring showing a negative relationship with irradiance. We concluded that light availability was mainly responsible for spatial variation in oak performance and proposed that small-scale overstory gaps aiming for direct sunlight exposure during early spring should achieve maximum understory oak performance with minimal pine removal.  相似文献   

Organogenic elements and compounds in surface samples from the sea of tranquillity     

Oró J  Updegrove WS  Gibert J  McReynolds J  Gil-Av E  Ibanez J  Zlatkis A  Flory DA  Levy RL  Wolf C 《Science (New York, N.Y.)》1970,167(3918):765-767

Organogenic elements, mainly carbon, nitrogen, phosphorus, and sulfur are present in the particulate material and in a breccia rock from Tranquillity Base in amounts ranging from 5 to 4200 parts per million. The major compounds of carbon released by heating are carbon monoxide and carbon dioxide; the former predominates. Small amounts of other compounds of carbon have also been observed. Sulfur can be released as hydrogen sulfide by treatment with acid. The carbon isotopic delta(13L)C values are definitely nonterrestrial (+ 13 to + 18.5 per mil).  相似文献   

Phycobiliprotein C-phycocyanin from Spirulina platensis is powerfully responsible for reducing oxidative stress and NADPH oxidase expression induced by an atherogenic diet in hamsters   总被引：1，自引：0，他引：1  

Riss J  Décordé K  Sutra T  Delage M  Baccou JC  Jouy N  Brune JP  Oréal H  Cristol JP  Rouanet JM 《Journal of agricultural and food chemistry》2007,55(19):7962-7967

The effects of spirulina and its chromophore phycocyanin, both without bound Se or selenium-enriched, were studied on plasma cholesterol, early atherosclerosis, cardiac production of superoxide anions, and NAD(P)H oxidase expression in hamsters. Forty hamsters were divided into 5 groups of 8 and fed an atherogenic diet for 12 weeks. They received by gavage either 7.14 mL/(kg day) phycocyanin (PC), Se-rich phycocyanin (SePC), spirulina (SP) or Se-rich spirulina (SeSP) in water, or water as control. SeSP and SePC supplied 0.4 microg of Se per 100 g body weight. Plasma cholesterol and non-HDL cholesterol concentrations were lower in group consuming SePC. HDL-cholesterol was never affected. SePC significantly increased plasma antioxidant capacity by 42% compared with controls. A sparing effect in liver glutathione peroxidase (87% on average) and superoxide dismutase (56% on average) activity was observed for all the groups compared to controls. Aortic fatty streak area was significantly reduced in the experimental groups, especially by PC (82%) and SePC (85%). Cardiac production of superoxide anion significantly decreased by approximately 46-76% in the four experimental groups and especially in SePC group (76%). The expression of p22phox subunit of NAD(P)H oxidase decreased by 34% after consumption of SePC. The results indicate that chronic consumption of Se-rich spirulina phycocyanin powerfully prevents the development of atherosclerosis. The underlying mechanism is related mainly to inhibiting pro-oxidant factors and at a lesser extent improving the serum lipid profile.  相似文献   

Genetic improvement of Israeli blue (Jordan) tilapia,Oreochromis aureus (Steindachner), through selective breeding for harvest weight     

Tatyana Zak  Raviv Deshev  Ayana Benet‐Perlberg  Alon Naor  Igal Magen  Yechiam Shapira  Raul W Ponzoni  Gideon Hulata 《Aquaculture Research》2014,45(3):546-557

Genetic parameters and selection responses were obtained for harvest body weight of blue tilapia (Oreochromis aureus) from data collected over three generations in a selected population. A total of 18 194 records representing 186 sires and 201 dams were used in the analysis. Within generation heritability estimates for harvest body weight ranged from 0.18 to 0.58. When data from more than one generation were included in the analysis, heritability estimates became more stable (0.33–0.40) and it was 0.33 when all data were included in the analysis. The common full‐sib effect accounted for 10% of the phenotypic variance in the full data set. Heritability for survival from stocking to harvest was estimated at 0.01 and 0.09 in actual units (fitting an animal model) and in the logit (sire model) scale respectively. The genetic correlation between harvest body weight and survival was 0.22 and not significantly different from zero. The total selection response for harvest body weight over the three generations of selection measured as the difference between least‐squares means of selected and control lines was 17.7%. The corresponding figure when response was measured as the difference between mean breeding values of selected and control lines was 19.6%. The average inbreeding coefficient was 0.003 after three generations of selection. These results indicate that there are good prospects for the genetic improvement of harvest body weight in blue tilapia.  相似文献