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1.
Nutr Cycl Agroecosyst ; 127(3): 375-392, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38025204

RESUMO

Soil nitrous oxide (N2O) fluxes comprise a significant part of the greenhouse gas emissions of agricultural products but are spatially and temporally variable, due to complex interactions between climate, soil and management variables. This study aimed to identify the main factors that affect N2O emissions under sugarcane, using a multi-site database from field experiments. Greenhouse gas fluxes, soil, climate, and management data were obtained from 13 field trials spanning the 2011-2017 period. We conducted exploratory, descriptive and inferential data analyses in experiments with varying fertiliser and stillage (vinasse) type and rate, and crop residue rates. The most relevant period of high N2O fluxes was the first 46 days after fertiliser application. The results indicate a strong positive correlation of cumulative N2O with nitrogen (N) fertiliser rate, soil fungi community (18S rRNA gene), soil ammonium (NH4+) and nitrate (NO3-); and a moderate negative correlation with amoA genes of ammonia-oxidising archaea (AOA) and soil organic matter content. The regression analysis revealed that easily routinely measured climate and management-related variables explained over 50% of the variation in cumulative N2O emissions, and that additional soil chemical and physical parameters improved the regression fit with an R2 = 0.65. Cross-wavelet analysis indicated significant correlations of N2O fluxes with rainfall and air temperature up to 64 days, associated with temporal lags of 2 to 4 days in some experiments, and presenting a good environmental control over fluxes in general. The nitrogen fertiliser mean emission factors ranged from 0.03 to 1.17% of N applied, with urea and ammonium nitrate plus vinasse producing high emissions, while ammonium sulphate, ammonium nitrate without vinasse, calcium nitrate, and mitigation alternatives (nitrification inhibitors and timing of vinasse application) producing low N2O-EFs. Measurements from multiple sites spanning several cropping seasons were useful for exploring the influence of environmental and management-related variables on soil N2O emissions in sugarcane production, providing support for global warming mitigation strategies, nitrogen management policies, and increased agricultural input efficiency. Supplementary Information: The online version contains supplementary material available at 10.1007/s10705-023-10321-w.

2.
Brain Res ; 907(1-2): 162-74, 2001 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-11430900

RESUMO

Several regulated mRNAs were detected by applying differential display to the mouse cerebellum during postnatal development. One cDNA fragment, referred to as CPD1 (GenBank U89345), was characterized and cloned. Northern blots showed maximum mRNA expression at postnatal day seven (P7). The mRNA encodes a protein of 260 amino acids. In situ RT-PCR showed that CPD1 is expressed mainly in granule cells and faintly in Purkinje cells. Polyclonal rabbit antibodies and oligobodies (oligonucleotide-based synthetic antibodies) revealed a protein of 34 kDa in Western blots. Immunohistochemistry showed not only marked nuclear staining but also mild cytoplasmic localization. Granule cells undergoing active division (P4) showed very little expression of CPD1 protein, which increases from P7 to P17. CPD1, affinity-purified using a chemically synthesized oligobody inhibits the activity of protein phosphatase PP2A but not protein phosphatase PP1. Differentiated PC12 cells also showed nuclear and cytoplasmic localization. Interestingly, maximal cytoplasmic CPD1/PP2A colocalization was observed near cell membrane regions that are far from growing neurites, and on growing cones. These results suggest that CPD1 might have an important role in cerebellar development.


Assuntos
Córtex Cerebelar/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Proteínas do Tecido Nervoso/biossíntese , Proteínas do Tecido Nervoso/genética , Sequência de Aminoácidos , Animais , Fator Natriurético Atrial , Northern Blotting , Western Blotting , Divisão Celular , Córtex Cerebelar/crescimento & desenvolvimento , Primers do DNA , DNA Complementar/genética , Inibidores Enzimáticos/química , Regulação Neoplásica da Expressão Gênica , Peptídeos e Proteínas de Sinalização Intracelular , Camundongos , Camundongos Endogâmicos C57BL , Chaperonas Moleculares , Dados de Sequência Molecular , Peso Molecular , Morfogênese , Proteínas do Tecido Nervoso/química , Proteínas Nucleares , Células PC12/metabolismo , Fragmentos de Peptídeos , Fosfoproteínas Fosfatases/antagonistas & inibidores , Precursores de Proteínas , Proteínas/química , Células de Purkinje/metabolismo , RNA Mensageiro/biossíntese , RNA Neoplásico/biossíntese , Proteínas de Ligação a RNA , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Sinapses/fisiologia
3.
J Neurosci Methods ; 105(1): 87-94, 2001 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-11166369

RESUMO

Differential display is a used widely and useful technique for the study of differentially expressed genes. However, very poor results have been obtained in the past when particular gene families were studied. Initially, we attempted to study the mRNA expression of catalytic subunits of serine/threonine phosphatases, using two primers specific to consensus sequences of these phosphatases. When differential display was applied, two wide, unresolved bands were isolated that contained cDNA of several phosphatases, together with that of many other unrelated transcripts. To overcome this problem, we used an alternative strategy, referred to as single strand differential display (SSDD), which is a combination of differential display and single strand conformation polymorphism (SSCP). After initial PCR amplification with specific primers, we ran a polyacrylamide (or agarose) gel, pre-selecting the region that contained fragments of the size expected for the consensus region (250-350 bp). The DNA eluted from this zone was then separated on a non-denaturing (SSCP) gel. Using this approach, we were able to characterize the expression of five ser/thr phosphatases, and a previously unreported splice variant of one of them, PP1gamma. All these phosphatases show varying levels of expression during development, indicating a very complex regulation of protein phosphorylation-dephosphorylation during the period of synaptogenesis in the mouse cerebellum.


Assuntos
Cerebelo/enzimologia , Cerebelo/crescimento & desenvolvimento , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica no Desenvolvimento/genética , Fosfoproteínas Fosfatases/genética , Polimorfismo Conformacional de Fita Simples , RNA Mensageiro/análise , Processamento Alternativo/genética , Animais , Northern Blotting , Diferenciação Celular/genética , Camundongos , Camundongos Endogâmicos C57BL , Proteínas do Tecido Nervoso/metabolismo , Fosfoproteínas Fosfatases/química , Fosforilação , Sinapses/genética , Sinapses/metabolismo
4.
Cogn Affect Behav Neurosci ; 1(4): 388-93, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12467090

RESUMO

In a recent study (Tafet, Toister-Achituv, & Shinitzky, 2001), we demonstrated that cortisol induces an increase in the expression of the gene coding for the serotonin transporter, associated with a subsequent elevation in the uptake of serotonin. This stimulatory effect, produced upon incubation with cortisol in vitro, was observed in peripheral blood lymphocytes from normal subjects. In the present work we investigated the cortisol-induced increase in serotonin uptake in lymphocytes from hypercortisolemic patients, including subjects with major depressive disorder (n = 8), and subjects with generalized anxiety disorder (n = 12), in comparison with a control group of normal healthy subjects (n = 8). A significant increase in serotonin uptake (+37% + 14, M + SD) was observed in the control group, whereas neither the generalized anxiety disorder nor the major depression group exhibited changes in serotonin uptake upon incubation with cortisol. It is likely that under chronic stress or depression, the capacity for increase in serotonin transporter has reached its limit due to the chronically elevated blood cortisol level. The physiological and diagnostic implications of this observation are discussed.


Assuntos
Proteínas de Transporte/fisiologia , Transtorno Depressivo Maior/fisiopatologia , Hidrocortisona/fisiologia , Glicoproteínas de Membrana/fisiologia , Proteínas de Membrana Transportadoras , Proteínas do Tecido Nervoso , Serotonina/sangue , Estresse Psicológico/fisiopatologia , Adulto , Nível de Alerta/fisiologia , Proteínas de Transporte/genética , Doença Crônica , Ritmo Circadiano/fisiologia , Feminino , Expressão Gênica/fisiologia , Humanos , Sistema Hipotálamo-Hipofisário/fisiopatologia , Linfócitos/metabolismo , Masculino , Glicoproteínas de Membrana/genética , Pessoa de Meia-Idade , Sistema Hipófise-Suprarrenal/fisiopatologia , Proteínas da Membrana Plasmática de Transporte de Serotonina
5.
Neuroreport ; 11(16): 3569-72, 2000 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-11095520

RESUMO

Our research objective was to characterize the biochemical effect of streptomycin during postnatal rat cerebral cortex development using a sensitive method that preserves the in situ topological relationship. We found a decrease in the mannosylation of asparagine-linked oligosaccharides without affecting polypeptide synthesis, DNA synthesis or glucose and mannose disappearance from the medium in mini-tissue units derived from P5. In addition, the rate of Dolp-GlcNAc2 Man9 Glc3 synthesis and the oligosaccharide protein transferase activity did not change in the presence of the aminoglycoside. These findings strongly suggested that the alteration of protein mannosylation occurred downstream of G3 transfer to nascent polypeptides. Further, the mini-tissue units may be useful for the assessment of neurological toxicity of antibacterial agents.


Assuntos
Córtex Cerebral/metabolismo , Hexosiltransferases , Proteínas de Membrana , Estreptomicina/farmacologia , Animais , Sequência de Carboidratos , Córtex Cerebral/efeitos dos fármacos , Glucose/metabolismo , Glicosilação/efeitos dos fármacos , Cinética , Manose/metabolismo , Dados de Sequência Molecular , Oligossacarídeos/biossíntese , Oligossacarídeos/química , Ratos , Ratos Wistar , Transferases/metabolismo
6.
J Neurosci Res ; 42(2): 220-7, 1995 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-8568922

RESUMO

Thy 1.2 is a well-known major cell surface glycoprotein of the central nervous system (CNS). However, the regulation of the expression of this molecule as well as its function are yet to be determined. To approach these problems we studied the synthesis of the molecule in the developing cerebellum of wild-type and staggerer mutant mice. We found the appearance of a [35S]-methionine-labeled band detected with specific Sepharose 4B-bound monoclonal antibodies (Mabs). The Thy 1.2 activity increases progressively from postnatal day 9 (P9), reaching the highest rate at P12, subsequently decreasing sharply at P13, and remaining relatively low up to P16 in the wild type. Comparison of these data to the rates of total protein synthesis reveals a selective developmental regulation of Thy 1.2 expression, at least at the translational level. This correlates quite well with the timing of synaptic stabilization between parallel fibers and Purkinje cell dendritic spines. Furthermore, at P12 Thy 1.2 protein is preferentially located in the synaptosomal fraction. The parallel fiber:Purkinje cell synapsis is not stabilized in the staggerer mutant mouse. At P12 Thy 1.2 synthesis is 30% of the wild type, indicating that the translational regulation of Thy 1.2 is altered in the staggerer mutation.


Assuntos
Cerebelo/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Proteínas do Tecido Nervoso/biossíntese , Antígenos Thy-1/biossíntese , Animais , Cerebelo/crescimento & desenvolvimento , Manose/metabolismo , Metionina/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes Neurológicos , Proteínas do Tecido Nervoso/genética , Técnicas de Cultura de Órgãos , Biossíntese de Proteínas , Células de Purkinje/metabolismo , Frações Subcelulares/metabolismo , Sinaptossomos/metabolismo , Antígenos Thy-1/genética
7.
J Neurochem ; 47(2): 355-62, 1986 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-3734783

RESUMO

Quantitative aspects of the pathway leading to the formation of asparagine-linked oligosaccharides were investigated in rat cerebral cortex. Steady-state labeling conditions were achieved with [2-3H]mannose by developing a micromethod of incubation of cerebral cortex particles in the presence of physiological concentrations of glucose (1 g/L). The rate of [2-3H]mannose uptake and incorporation into protein was markedly affected when the concentration of glucose was lowered to 0.05 g/L. It was found that in the presence of glucose (1 g/L), a minor fraction of the utilized [2-3H]mannose is used in glycoprotein formation and the remaining labeled sugar enters the other major metabolic pathways, generating tritiated water which is rapidly exchanged with that of the medium. Under these conditions, the intracellular isotopic dilution of [2-3H]mannose-labeled precursors was calculated to be about 11.5-fold. These data allow determination of the rate of the net transfer of mannose into proteins. Comparison of the rate of glycosylation between 5- and 30-day-old cerebral cortex revealed a striking difference: 2.1 and 0.3 ng of mannose/mg protein/h, respectively.


Assuntos
Córtex Cerebral/metabolismo , Glicoproteínas/biossíntese , Proteínas do Tecido Nervoso/biossíntese , Envelhecimento , Animais , Córtex Cerebral/efeitos dos fármacos , Difusão , Glucose/metabolismo , Glucose/farmacologia , Cinética , Leucina/metabolismo , Manose/metabolismo , Ratos , Ratos Endogâmicos , Trítio
8.
J Neurochem ; 38(5): 1236-40, 1982 May.
Artigo em Inglês | MEDLINE | ID: mdl-7062049

RESUMO

A soluble fraction from rat brain neuronal perikarya was shown to contain both the specific and nonspecific forms of the enzyme acetylcholinesterase (EC's 3.1.1.7. and 3.1.1.8., respectively). The ratio of the enzyme activities varied along the course of brain development: the nonspecific form being predominant from 1 to 15 days of age and the specific one showing the pattern of rising activity from day 15 onward. We suggest a possible relationship between this changing in cholinesterase activities and the establishment of synapses within the rat cerebral cortex.


Assuntos
Acetilcolinesterase/metabolismo , Encéfalo/crescimento & desenvolvimento , Colinesterases/metabolismo , Neurônios/enzimologia , Animais , Benzenamina, 4,4'-(3-oxo-1,5-pentanodi-il)bis(N,N-dimetil-N-2-propenil-), Dibrometo/farmacologia , Trietiodeto de Galamina/farmacologia , Neurônios/efeitos dos fármacos , Concentração Osmolar , Ratos , Frações Subcelulares/enzimologia , Sinapses/fisiologia
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