Effects of deforestation on contents and distribution of amino sugars within particle-size fractions of mountain soils     

María-Belén Turrión  Bruno Glaser  Wolfgang Zech 《Biology and Fertility of Soils》2002,35(1):49-53

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Release of nucleotides and nucleosides during yeast autolysis: kinetics and potential impact on flavor     

Charpentier C  Aussenac J  Charpentier M  Prome JC  Duteurtre B  Feuillat M 《Journal of agricultural and food chemistry》2005,53(8):3000-3007

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Ammonium‐driven nitrification plays a key role in increasing Mn availability in calcareous soils     

Michael Dreyer  Merle Wichmann  Marie Rischen  Bruno M. Görlach  Annika Ehmke  Britta Pitann  Karl H. Mühling 《植物养料与土壤学杂志》2020,183(3):389-396

Background : Manganese deficiency often becomes a yield limiting factor, particularly on calcareous soils, even though the total soil manganese content is usually sufficient. Although it is known that acidifying N fertilizers can improve Mn availability, the reason of this effect is still unknown. Aim : Our aim was to investigate the effect of stabilized ammonium fertilizers as a tool to distinguish between physiological‐ and nitrification‐induced acidification. Method : Two pot experiments with Triticum aestivum L. and one soil incubation experiment using different nitrogen forms (CN = calcium nitrate, AN = ammonium nitrate, AS = ammonium sulfate, ATS = ammonium thiosulfate) with and without addition of nitrification inhibitors (DCD, Nitrapyrin, Piadin, DMPP) were conducted to examine the effect on Mn availability in the soil and Mn uptake by the plants at different development stages (EC 31 und 39). Results : With increasing fertilizer ${\mathrm{NH}}_4^{+}$ content a higher Mn concentration was detected: CN: 32 µg Mn g^?1 DM, AN: 39 µg Mn g^?1 DW, AS: 55 µg Mn g^?1 DM, ATS: 109 µg Mn g^?1 DM. The addition of a nitrification inhibitor resulted in a significantly lower rhizosphere pH compared to the non‐stabilized fertilizer. Surprisingly, the use of different nitrification inhibitors led to unchanged (CN, AN) or lower Mn concentrations of wheat. Especially in the ${\mathrm{NH}}_4^{+}$ treatments (AS and ATS), this negative effect was very evident (AS+DCD: 42 µg Mn g^?1 DM; ATS+DCD: 55 µg Mn g^?1 DM). Conclusions : Mn availability was enhanced by ongoing nitrification process rather than physiological acidification. Compared to other N forms, ammonium thiosulfate led to the highest Mn availability in bulk soil.  相似文献   

The involvement of the anterior cingulate cortex in remote contextual fear memory   总被引：1，自引：0，他引：1  

Frankland PW  Bontempi B  Talton LE  Kaczmarek L  Silva AJ 《Science (New York, N.Y.)》2004,304(5672):881-883

Although the molecular, cellular, and systems mechanisms required for initial memory processing have been intensively investigated, those underlying permanent memory storage remain elusive. We present neuroanatomical, pharmacological, and genetic results demonstrating that the anterior cingulate cortex plays a critical role in remote memory for contextual fear conditioning. Imaging of activity-dependent genes shows that the anterior cingulate is activated by remote memory and that this activation is impaired by a null alpha-CaMKII mutation that blocks remote memory. Accordingly, reversible inactivation of this structure in normal mice disrupts remote memory without affecting recent memory.  相似文献   

Geochemistry. Are volcanic gases serial killers?     

Scaillet B 《Science (New York, N.Y.)》2008,319(5870):1628-1629

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Endocannabinoid hydrolysis generates brain prostaglandins that promote neuroinflammation   总被引：2，自引：0，他引：2  

Nomura DK  Morrison BE  Blankman JL  Long JZ  Kinsey SG  Marcondes MC  Ward AM  Hahn YK  Lichtman AH  Conti B  Cravatt BF 《Science (New York, N.Y.)》2011,334(6057):809-813

Phospholipase A(2)(PLA(2)) enzymes are considered the primary source of arachidonic acid for cyclooxygenase (COX)-mediated biosynthesis of prostaglandins. Here, we show that a distinct pathway exists in brain, where monoacylglycerol lipase (MAGL) hydrolyzes the endocannabinoid 2-arachidonoylglycerol to generate a major arachidonate precursor pool for neuroinflammatory prostaglandins. MAGL-disrupted animals show neuroprotection in a parkinsonian mouse model. These animals are spared the hemorrhaging caused by COX inhibitors in the gut, where prostaglandins are instead regulated by cytosolic PLA(2). These findings identify MAGL as a distinct metabolic node that couples endocannabinoid to prostaglandin signaling networks in the nervous system and suggest that inhibition of this enzyme may be a new and potentially safer way to suppress the proinflammatory cascades that underlie neurodegenerative disorders.  相似文献   

Cerebellum shapes hippocampal spatial code     

Rochefort C  Arabo A  André M  Poucet B  Save E  Rondi-Reig L 《Science (New York, N.Y.)》2011,334(6054):385-389

Spatial representation is an active process that requires complex multimodal integration from a large interacting network of cortical and subcortical structures. We sought to determine the role of cerebellar protein kinase C (PKC)-dependent plasticity in spatial navigation by recording the activity of hippocampal place cells in transgenic L7PKCI mice with selective disruption of PKC-dependent plasticity at parallel fiber-Purkinje cell synapses. Place cell properties were exclusively impaired when L7PKCI mice had to rely on self-motion cues. The behavioral consequence of such a deficit is evidenced here by selectively impaired navigation capabilities during a path integration task. Together, these results suggest that cerebellar PKC-dependent mechanisms are involved in processing self-motion signals essential to the shaping of hippocampal spatial representation.  相似文献   

Preserved feedforward but impaired top-down processes in the vegetative state     

Boly M  Garrido MI  Gosseries O  Bruno MA  Boveroux P  Schnakers C  Massimini M  Litvak V  Laureys S  Friston K 《Science (New York, N.Y.)》2011,332(6031):858-862

Frontoparietal cortex is involved in the explicit processing (awareness) of stimuli. Frontoparietal activation has also been found in studies of subliminal stimulus processing. We hypothesized that an impairment of top-down processes, involved in recurrent neuronal message-passing and the generation of long-latency electrophysiological responses, might provide a more reliable correlate of consciousness in severely brain-damaged patients, than frontoparietal responses. We measured effective connectivity during a mismatch negativity paradigm and found that the only significant difference between patients in a vegetative state and controls was an impairment of backward connectivity from frontal to temporal cortices. This result emphasizes the importance of top-down projections in recurrent processing that involve high-order associative cortices for conscious perception.  相似文献   

Psychology. Happy people live longer     

Frey BS 《Science (New York, N.Y.)》2011,331(6017):542-543

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Molecular biology. Breaking the silence     

Owen-Hughes T  Bruno M 《Science (New York, N.Y.)》2004,303(5656):324-325

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