We analyzed the diatom assemblages inhabiting the epipelic biofilm of a Pampean stream, characterized by their high basal nutrient levels, when exposed to a continuous surplus of inorganic nutrients. ...An in situ experience was conducted, increasing concentrations of N and P in water 3-fold from the basal concentration. Nutrient enrichment was achieved by the use of fertilizer bags distributed along the reach. The period of exposure was of 14 months. The effects of nutrient enrichment were analyzed following a BACIPS ANOVA design. The changes in nutrient concentration were associated with a significant increase in diatom density and a decrease in species richness and diversity. The additional nutrient load also caused the change in the diatom taxa proportion, favoring motile forms, Nitzschia species mainly. The fertilization in La Choza, caused a mild to moderate effect, indeed not immediate, on the diatom assemblage. These delayed responses of moderate intensity could be related with intrinsic characteristics of diatom assemblages pre-adapted to nutrient-rich environments. The rising urbanization and agricultural activity in the Pampean plain, may seriously impair the biodiversity of its rivers if the entrance of nutrients to these ecosystems is not mitigated.
Epitope tagging is widely used to fuse a known epitope to proteins for which no affinity receptor is available by using recombinant DNA technology. One example is FLAG epitope (DYKDDDDK), which ...provides better purity and recoveries than the favorite poly histidine tag. However, purification requires using anti-FLAG antibody resins, the high cost and nonreusability of which restrict widespread use. One cost-effective solution is provided by the use of bioinspired anti-FLAG molecularly imprinted polymers (MIPs). This work describes the development of MIPs, based on the epitope approach, synthesized from the tetrapeptide DYKD as template that affords purification of FLAG-derived recombinant proteins. Polymer was optimized by using a combinatorial approach to select the functional monomer(s) and cross-linker(s), resulting in the best specific affinity toward FLAG and the peptide DYKD. The imprinted resin obtained was used to purify mCherry proteins tagged with either FLAG or DYKD epitopes from crude cell lysates. Both mCherry variants were highly efficiently purified (R ≥ 95%, RSD ≤ 15%, n = 3) and impurities were removed. Unlike existing antibody-based resins, the proposed tag-imprinting strategy provides a general method for meeting the growing demand for efficient, inexpensive, and versatile materials for tagged proteins purification.
Bio-oil from the fast pyrolysis of agro-residues still needs to contemplate different production scenarios to look for its feasibility. For this reason, in this work the effect of a range of fast ...pyrolysis temperature (450, 480, 510 and 550°C) processing rape straw biomass (with high K content) has been studied in a continuous bubbling fluidised bed reactor. It was found that the catalytic effect of the inorganic content was different at each fast pyrolysis temperature, with the lower temperatures resulting in the highest yield of bio-oil due to minor catalytic effect (up to 41.39wt%). It was also found that at 480°C the bio-oil presented the best combination of physico-chemical features such as non-separation phase and the lowest water content; yield (39.65wt%) and HHV (19.23MJ/kg), containing a high concentration of phenolic compounds. At the fast pyrolysis temperature of 510°C and 550°C, the conjunction effect of temperature and the catalytic effect provoked bio-oil separation into two phases and a higher gas yield than was expected. Then, the higher temperatures are not suitable for bio-oil production. Char is also an interesting co-product for all pyrolysis temperatures.
•The conjunction of temperature and K content affects mass and energy distribution.•Low pyrolysis temperatures reduce water in bio-oils avoiding phase separation.•Pyrolysis of a high ash biomass (with high K content) tends to form phenols.•Storage tests showed a degradative behavior in bio-oils.
The dilution and amplification effects are important concepts in the field of zoonotic diseases. While the dilution effect predicts that pathogen prevalence is negatively correlated with increased ...species diversity, the opposite trend is observed when the amplification effect occurs. Understanding how interspecific interactions such as predation and competition within a community influence disease transmission is highly relevant. We explore the conditions under which the dilution and amplification effects arise, using compartmental models that integrate ecological and epidemiological interactions. We formulate an intraguild predation model where each species is divided into two compartments: susceptible and infected individuals. We obtained that increasing predation increases the disease transmission potential of the predator and the density of infected individuals, but decreases the disease transmission potential of the prey, as well as their density. Also, we found that interspecific competition always helps to decrease the number of infected individuals in the population of the two species. Therefore, dilution and amplification effects can be observed simultaneously but depending on different types of cological interactions.
Pest risk maps are powerful visual communication tools to describe where invasive alien species might arrive, establish, spread, or cause harmful impacts. These maps inform strategic and tactical ...pest management decisions, such as potential restrictions on international trade or the design of pest surveys and domestic quarantines. Diverse methods are available to create pest risk maps, and can potentially yield different depictions of risk for the same species. Inherent uncertainties about the biology of the invader, future climate conditions, and species interactions further complicate map interpretation. If multiple maps are available, risk managers must choose how to incorporate the various representations of risk into their decisionmaking process, and may make significant errors if they misunderstand what each map portrays. This article describes the need for pest risk maps, compares pest risk mapping methods, and recommends future research to improve such important decision-support tools.
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