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| Registros recuperados: 95 | |
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| Petrolia, Daniel R.; Gowda, Prasanna H.; Mulla, David J.. |
| Agricultural nitrogen losses are the major contributor to nitrogen loads in the Mississippi River, and consequently, to the existence of a hypoxic, or "dead", zone in the Gulf of Mexico. Focusing on two small agricultural watersheds in southwestern Minnesota, simulation results from the Agricultural Drainage And Pesticide Management (ADAPT) model were combined with a linear-optimization model to evaluate the environmental and economic impact of alternative land-use policies for reducing nitrogen losses. Of particular importance was the study's explicit focus on agricultural subsurface (tile) drainage, which has been identified as the major pathway for agricultural nitrogen losses in the upper Midwest, and the use of drainage-focused abatement policies.... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Drainage; Hypoxia; ADAPT; Nitrogen; Watershed; Environmental Economics and Policy. |
| Ano: 2005 |
URL: http://purl.umn.edu/19416 |
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| Thomas,André Luís; Sodek,Ladaslav. |
| The transport of organic N compounds to the shoot in the xylem sap of nodulated soybean plants was investigated in an attempt to better understand the changes in N metabolism under root hypoxia (first 5 days of flooding), with different sources of N in the medium. NO3- is beneficial for tolerance of plants to waterlogging, whereas other N sources such as NH4+ and NH4NO3, are not. Nevertheless, in the presence of NH4+ high levels of amino acids were transported in the xylem, consistent with its assimilation. Some increase in the transport of amino acids was also seen with NO3- nutrition during waterlogging, but not with N-free medium. Ureide transport in the xylem was severely reduced during waterlogging, consistent with impaired N2 fixation under these... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Glycine max; Alanine; Hypoxia; N metabolism. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202006000200010 |
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| Petrolia, Daniel R.; Gowda, Prasanna H.. |
| Agricultural nitrogen is a major contributor to Gulf of Mexico hypoxia, and research has shown that agricultural subsurface tile drainage is a major carrier of nitrogen from croplands to streams and rivers. This study compares the results of abating nitrogen under a retired-land minimization policy with those of a new revenue-maximizing policy, paying particular attention to the role of tile-drained land. Findings reveal the retirement-minimizing policy resulted in more tile-drained land being retired and less being fertilizer-managed than was optimal under the net-return maximizing policy. Also, it led to a greater economic burden being shouldered by tile-drained land. Under both cases, tile drainage dominated the abatement process. |
| Tipo: Journal Article |
Palavras-chave: Abatement; ADAPT; Drainage; Hypoxia; Nitrogen; Crop Production/Industries; Land Economics/Use. |
| Ano: 2006 |
URL: http://purl.umn.edu/8621 |
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| Zambonino, Jose-luis; Mazurais, David; Dubuc, Alexia; Queau, Pierre; Vanderplancke, Gwenaelle; Servili, Arianna; Cahu, Chantal; Le Bayon, Nicolas; Huelvan, Christine; Claireaux, Guy. |
| Ocean warming, eutrophication and consequent decrease in oxygen lead to smaller average fish size. Although such responses are well-known in an evolutionary context, involving multiple generations, it appears to be incompatible with current rapid environmental change. Rather, phenotypic plasticity could provide a means for marine fish to cope with rapid environmental changes. However, little is known about the mechanisms underlying plastic responses to environmental conditions that favour small phenotypes. Our aim was to investigate how and why European sea bass that had experienced a short episode of moderate hypoxia during their larval stage subsequently exhibited a growth depression at the juvenile stage compared to the control group. We examined... |
| Tipo: Text |
Palavras-chave: Climate change; Digestive enzymes; Dicentrarchus labrax; Growth; Hypoxia; Respirometry. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00373/48407/48635.pdf |
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| KOLB,ROSANA M.; MEDRI,MOACYR E.; BIANCHINI,EDMILSON; PIMENTA,JOSÉ A.; GILONI,PATRICIA C.; CORREA,GERALDO T.. |
| Em matas ciliares da Bacia Hidrográfica do Rio Tibagi, nas áreas sujeitas a inundações periódicas, é comum a ocorrência de S. commersoniana onde, geralmente, se torna a espécie dominante. A fim de elucidar alguns aspectos de tolerância ao alagamento, plantas dessa espécie foram mantidas na capacidade de campo e em solo alagado por dois meses. Após esse período, algumas plantas foram desalagadas para verificar o comportamento da espécie no período de reaeração. O alagamento induziu, em raízes, aumento de espaços intercelulares, redução na espessura do cilindro central e aumento na espessura do córtex. Plantas alagadas cresceram menos que as controle e desenvolveram lenticelas hipertróficas caulinares e algumas raízes adventícias. Plantas reaeradas retomaram... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ecological anatomy; Hypoxia; Sebastiania commersoniana. |
| Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84041998000300010 |
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| Oliveira,Adilson Serafim de; Ferreira,Cristiane Silva; Graciano-Ribeiro,Dalva; Franco,Augusto César. |
| Wetlands are common in the Cerrado (Brazilian savannas) biome, however flooding of these wetlands impairs growth and development of most plants. We evaluated flood tolerance of typical Cerrado trees. Seedlings of Aspidosperma macrocarpon (Apocynaceae), Tabebuia rosea (Bignoniaceae), Handroanthus chrysotrichus (Bignoniaceae), Myracrodruon urundeuva (Anacardiaceae), Kielmeyera coriacea (Calophyllaceae) and Copaifera langsdorffii (Fabaceae) were flooded up to the stem base for 30 days. Stems with cortical cracks, secondary aerenchyma and hypertrophic lenticels were observed in flooded plants of M. urundeuva,H. chrysotrichus and T. rosea while adventitious roots were formed in flooded plants of T. rosea and H. chrysotrichus. However, only T. rosea developed... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aerenchyma; Biomass partitioning; Flood tolerance; Hypoxia; Water stress. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062015000400478 |
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| Camelo Jr.,J.S.; Martins,A.R.; Rosa,E.; Ramos,S.G.; Hehre,D.; Bancalari,E.; Suguihara,C.. |
| The objective of this study was to observe possible interactions between the renin-angiotensin and nitrergic systems in chronic hypoxia-induced pulmonary hypertension in newborn piglets. Thirteen chronically instrumented newborn piglets (6.3 ± 0.9 days; 2369 ± 491 g) were randomly assigned to receive saline (placebo, P) or the AT1 receptor (AT1-R) blocker L-158,809 (L) during 6 days of hypoxia (FiO2 = 0.12). During hypoxia, pulmonary arterial pressure (Ppa; P < 0.0001), pulmonary vascular resistance (PVR; P < 0.02) and the pulmonary to systemic vascular resistance ratio (PVR/SVR; P < 0.05) were significantly attenuated in the L (N = 7) group compared to the P group (N = 6). Western blot analysis of lung proteins showed a significant decrease of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Newborn animals; Pulmonary hypertension; Angiotensin II; Angiotensin receptors; Hypoxia. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012000200012 |
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| Almeida-Val,Vera Maria Fonseca; Oliveira,Alice Reis; Silva,Maria de Nazaré Paula da; Ferreira-Nozawa,Monica Stropa; Araújo,Roziete Mendes; Val,Adalberto Luis; Nozawa,Sérgio Ricardo. |
| Adaptation or acclimation to hypoxia occurs via the modulation of physiologically relevant genes, such as erythropoietin, transferrin, vascular endothelial growth factor, phosphofructokinase and lactate dehydrogenase A. In the present study, we have cloned, sequenced and examined the modulation of the LDH-A gene after an Amazonian fish species, Astronotus crassipinis (the Oscar), was exposed to hypoxia and anoxia. In earlier studies, we have discovered that adults of this species are extremely tolerant to hypoxia and anoxia, while the juveniles are less tolerant. Exposure of juveniles to acute hypoxia and anoxia resulted in increased LDH-A gene expression in skeletal and cardiac muscles. When exposed to graded hypoxia juveniles show decreased LDH-A... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amazon; Fishes; Gene expression; RT-PCR; LDH-A; Hypoxia; Anoxia. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572011000200025 |
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| Mauduit, Florian; Domenici, P.; Farrell, A. P.; Lacroix, C.; Le Floch, S.; Lemaire, P.; Nicolas-kopec, A.; Whittington, M.; Zambonino-infante, Jose-luis; Claireaux, Guy. |
| Human alteration of marine ecosystems is substantial and growing. Yet, no adequate methodology exists that provides reliable predictions of how environmental degradation will affect these ecosystems at a relevant level of biological organization. The primary objective of this study was to develop a methodology to evaluate a fish’s capacity to face a well-established environmental challenge, an exposure to chemically dispersed oil, and characterize the long-term consequences. Therefore, we applied high-throughput, non-lethal challenge tests to assess hypoxia tolerance, temperature susceptibility and maximal swimming speed as proxies for a fish’s functional integrity. These whole animal challenge tests were implemented before (1 month) and after (1 month)... |
| Tipo: Text |
Palavras-chave: Fish; Oil spill; Dispersant; Biomarkers; Physiological integrity; Ecological performance; Temperature; Hypoxia; Swimming; Growth. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00347/45828/45916.pdf |
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| Mauduit, Florian; Farrell, Anthony P.; Domenici, Paolo; Lacroix, Camille; Le Floch, Stephane; Lemaire, Pphilippe; Nicolas-kopec, Annabelle; Whittington, Mark; Le Bayon, Nicolas; Zambonino-infante, Jose-luis; Claireaux, Guy. |
| Consequences of exposure to polyaromatic hydrocarbons (PAH), toxic components of crude oil, on fish has been widely documented due to their ecological and economical importance. However, although forming a valuable and consistent body of knowledge, use of these data in spill response is limited. Objective of the present study was thus to facilitate the translation of published data into information of operational value. For this, we investigated the dose‐response relationship between dispersant‐treated oil exposure and ecologically‐relevant consequences by combining laboratory and field experiments. Effects were examined over almost a year using juveniles of the slow growing, commercially important European sea bass (Dicentrarchus labrax). Moreover, a... |
| Tipo: Text |
Palavras-chave: Oil spills; Polycyclic aromatic hydrocarbons (PAHs); Fish indices; Hypoxia; Temperature. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00455/56679/58438.pdf |
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| GAMBOA,JORGE; CACEDA,RICARDO; GAMBOA,ALFREDO; MONGE-C,CARLOS. |
| Red blood cell carbonic anhydrase (CA) activity has not been studied in high altitude natives. Because CA is an intraerythocytic enzyme and high altitude natives are polycythemic, it is important to know if the activity of CA per red cell volume is different from that of their sea level counterparts. Blood was collected from healthy subjects living in Lima (150m) and from twelve subjects from Cerro de Pasco (4330m), and hematocrit and carbonic anhydrase activity were measured. As expected, the high altitude natives had significantly higher hematocrits than the sea level controls (p=0.0002). No difference in the CA activity per milliliter of red cells was found between the two populations. There was no correlation between the hematocrit and CA activity. |
| Tipo: Journal article |
Palavras-chave: Carbonic anhydrase; Hypoxia; Polycythemia. |
| Ano: 2000 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602000000300006 |
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| Xu,Y.; Xu,Y.; Luan,H.; Jiang,Y.; Tian,X.; Zhang,S.. |
| Phosphorylated-cyclic adenosine monophosphate response element-binding protein (Phospho-CREB) has an important role in the pathogenesis of myocardial ischemia. We isolated the iridoid glycoside cornin from the fruit of Verbena officinalis L, investigated its effects against myocardial ischemia and reperfusion (I/R) injury in vivo, and elucidated its potential mechanism in vitro. Effects of cornin on cell viability, as well as expression of phospho-CREB and phospho-Akt in hypoxic H9c2 cells in vitro, and myocardial I/R injury in vivo, were investigated. Cornin attenuated hypoxia-induced cytotoxicity significantly in H9c2 cells in a concentration-dependent manner. Treatment of H9c2 cells with cornin (10 µM) blocked the reduction of expression of phospho-CREB... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cornin; Myocardial ischemia and reperfusion; CREB; Akt; Hypoxia. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2016000200608 |
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| Marshall,J.M.. |
| This review describes the ways in which the primary bradycardia and peripheral vasoconstriction evoked by selective stimulation of peripheral chemoreceptors can be modified by the secondary effects of a chemoreceptor-induced increase in ventilation. The evidence that strong stimulation of peripheral chemoreceptors can evoke the behavioural and cardiovascular components of the alerting or defence response which is characteristically evoked by novel or noxious stimuli is considered. The functional significance of all these influences in systemic hypoxia is then discussed with emphasis on the fact that these reflex changes can be overcome by the local effects of hypoxia: central neural hypoxia depresses ventilation, hypoxia acting on the heart causes... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Hypoxia; Adenosine; Chemoreceptors; Vasodilatation; Noradrenaline. |
| Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998000700002 |
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| Heon Ryu,Mi; Hee Park,Jeong; Eun Park,Ji; Chung,Jin; Hun Lee,Chang; Ryoun Park,Hae. |
| Tumor cells are often found under hypoxic conditions due to the rapid outgrowth of their vascular supply, and, in order to survive hypoxia, these cells induce numerous signaling factors. Akt is an important kinase in cell survival, and its activity is regulated by the upstream phosphoinositide 3-kinase (PI3K) and receptor tyrosine kinases (RTKs). In this study, we examined Akt activation and RTKs/PI3K/Akt signaling using the hypoxia-mimetic cobalt chloride in oral squamous carcinoma cells. Cobalt chloride increases Akt phosphorylation in both a dose- and time-dependent manner. Blocking the activation of the PI3K/Akt pathway using LY294002 abolished Akt activation in response to cobalt chloride, suggesting that Akt phosphorylation by cobalt chloride is... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Hypoxia; DNA synthesis; S-phase. |
| Ano: 2010 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0327-95452010000100003 |
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| Pichavant, Karine; Person, Jeannine; Le Bayon, Nicolas; Severe, Armelle; Le Roux, Annick; Boeuf, Gilles. |
| When juvenile turbot Scophthulmus maximus and sea bass Dicentrarchus labrax were fed to satiation, growth and food intake were depressed under hypoxia (3.2 +/- 0.3 and 4.5 +/- 0.2 mg O-2 l(-1)). However, no significant difference in growth was observed between fishes maintained in hypoxia and fed to satiation and fishes reared in normoxia (7.4 +/- 0.3 mg O-2 l(-1)) and fed restricted rations (same food intake of fishes at 3.2 mg O-2 l(-1)). Routine oxygen consumption of fishes fed to satiation was higher in normoxia than in hypoxia due to the decrease in food intake in the latter. Of the physiological parameters measured, no significant changes were observed in the two species maintained in hypoxia. This study confirms the significant interaction between... |
| Tipo: Text |
Palavras-chave: Oxygen consumption; Growth; Hypoxia; Sea bass; Turbot. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-617.pdf |
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| Registros recuperados: 95 | |
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