30 research outputs found
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How organized is deep convection over Germany?
Deep moist convection shows a tendency to organize into mesoscale structures. To be able to understand the potential effect of convective organization on the climate, one needs first to characterize organization. In this study, we systematically characterize the organizational state of convection over Germany based on two years of cloud-top observations derived from the Meteosat Second Generation satellite and of precipitation cores detected by the German C-band radar network. The organizational state of convection is characterized by commonly employed organization indices, which are mostly based on the object numbers, sizes and nearest-neighbour distances. According to the organization index Iorg, cloud tops and precipitation cores are found to be in an organized state for 69% and 92% of the time, respectively. There is an increase in rainfall when the number of objects and their sizes increase, independently of the organizational state. Case-studies of specific days suggest that convectively organized states correspond to either local multi-cell clusters, with less numerous, larger objects close to each other, or to scattered clusters, with more numerous, smaller organized objects spread out over the domain. For those days, simulations are performed with the large-eddy model ICON with grid spacings of 625, 312 and 156?m. Although the model underestimates rainfall and shows a too large cold cloud coverage, the organizational state is reasonably well represented without significant differences between the grid spacings
Simple and efficient expression of Agaricus meleagris pyranose dehydrogenase in Pichia pastoris
Pyranose dehydrogenase (PDH) is a fungal flavin-dependent sugar oxidoreductase that is highly interesting for applications in organic synthesis or electrochemistry. The low expression levels of the filamentous fungus Agaricus meleagris as well as the demand for engineered PDH make heterologous expression necessary. Recently, Aspergillus species were described to efficiently secrete recombinant PDH. Here, we evaluate recombinant protein production with expression hosts more suitable for genetic engineering. Expression in Escherichia coli resulted in no soluble or active PDH. Heterologous expression in the methylotrophic yeast Pichia pastoris was investigated using two different signal sequences as well as a codon-optimized sequence. A 96-well plate activity screening for transformants of all constructs was established and the best expressing clone was used for large-scale production in 50-L scale, which gave a volumetric yield of 223 mg Lâ1 PDH or 1,330 UâLâ1 dâ1 in spaceâtime yield. Purification yielded 13.4 g of pure enzyme representing 95.8% of the initial activity. The hyperglycosylated recombinant enzyme had a 20% lower specific activity than the native enzyme; however, the kinetic properties were essentially identical. This study demonstrates the successful expression of PDH in the eukaryotic host organism P. pastoris paving the way for protein engineering. Additionally, the feasibility of large-scale production of the enzyme with this expression system together with a simplified purification scheme for easy high-yield purification is shown
Impact of resolution on large-eddy simulation of midlatitude summertime convection
We analyze life cycles of summer time moist convection of a Large Eddy Simulation (LES) in a limited area setup over Germany. The goal is to assess the ability of the model to represent convective organization in space and time in comparison to radar data, and its sensitivity to daily mean surface air temperature. A continuous period of 36 days in May and June 2016, showing a considerable amount of convective rainfall which covers large parts of the domain on most of the days, is simulated with a grid spacing of 625âm. Using convective organization indices, and a tracking algorithm for convective precipitation events, we find that an LES with 625âm grid spacing tends to underestimate the degree of convective organization, and shows a weaker sensitivity of heavy convective rainfall to temperature as suggested by the radar data. An analysis of three days within this period that are simulated with finer grid spacing of 312âm and 156âm showed, that a grid spacing at the 100âm scale has the potential to improve the simulated diurnal cycles of convection, the mean time evolution of single convective events, and the degree of convective organization
Relação entre excreção de creatinina e dieta, atividade fĂsica e volume urinĂĄrio, em crianças de 5 -| 12 anos de idade Relationship between creatinine excretion, diet, physical activity and urinary volume in children 5 to 12 years of age
Foi feito um estudo da excreção da creatinina e sua relação com a dieta, atividade fĂsica e volume urinĂĄrio em indivĂduos entre 5 -| 12 anos de idade, mantendo suas condiçÔes habituais de vida. A anĂĄlise qualitativa da dieta mostrou que a possibilidade de ingestĂŁo de creatina e creatinina ocorreu na hora do almoço. No que se refere Ă atividade fĂsica, o perĂodo da manhĂŁ e o noturno foram de relativo repouso, concentrando-se as atividades fĂsicas no perĂodo da tarde. NĂŁo houve diferença, estatisticamente, significante entre a excreção mĂ©dia de creatinina dos perĂodos da manhĂŁ e da tarde e tambĂ©m entre a excreção mĂ©dia dos perĂodos diurno e noturno, sugerindo, conseqĂŒentemente, uma nĂŁo relação entre dieta, atividade fĂsica e excreção de creatinina. Houve uma diferença estatisticamente significante entre o volume mĂ©dio urinĂĄrio do perĂodo diurno e o do perĂodo noturno, sugerindo com isso uma independĂȘncia entre ele e a creatinina excretada. Encontrou-se, entretanto, uma correlação significante entre ambos que, possivelmente esteja ligada ao fato das amostras terem sido colhidas em Ă©pocas de frio intenso, em que os indivĂduos ingerem pouco lĂquido, e conseqĂŒentemente a urina estivesse com uma concentração elevada de seus diferentes constituintes.<br>A study on the relationship between creatinine excretion and diet, physical activity and urinary volume was carried out on children from 5 to 12 years of age, observing usual life conditions. Qualitative analysis of diet revealed that possibly ingestion of creatine and creatinine ocurred with the noon meal. Regarding physical activity the data showed that the peak of activity occurred in the afternoon. The differences between average excretion of creatine corresponding to morning and afternoon periods were not statistically significant, the same being observed when diurnal and nocturnal averages of excretion were considered. On the other hand, the average volumes corresponding to diurnal and nocturnal periods revealed a significant difference, which suggests independence between creatinine excretion and urinary volume. However data show a positive significant correlation between creatinine excretion and urinary volume when individual results were considered