158 research outputs found
The Aerobic Biodegradation Kinetics of Plant Tannins in Industrial Wastewater
This paper describes an experimental determination of the biodegradation rate for tannins present in industrial wastewater, after the extraction of chestnut chips. Experiments were performed in a laboratory aerobic reactor (Armfield) by using biomass from an existing industrial wastewater treatment plant. The outlet tannins concentration was determined under various processing conditions. Simultaneously, an optical microscope was used to monitor the mix of microbiological cultures in the biomass. On the basis of data obtained in experiments, non-linear regression was used to perform parametric analysis of various kinetic models, which took into account inhibition, as quoted in literature (Haldane, Edwards, Aiba, Luong). The statistical analysis, based on the P-criterion, F-criterion, adjusted coefficient of determination, Kolmogorov-Smirnov test and root
mean squared error, showed that the biodegradation of plant tannins in industrial wastewater under selected conditions for aerobic digestion, can be most successfully described statistically by the Aiba\u27s kinetic model
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The Serine Protease Homolog, Scarface, Is Sensitive to Nutrient Availability and Modulates the Development of the <i>Drosophila</i> Blood-Brain Barrier.
The adaptable transcriptional response to changes in food availability not only ensures animal survival but also lets embryonic development progress. Interestingly, the CNS is preferentially protected from periods of malnutrition, a phenomenon known as "brain sparing." However, the mechanisms that mediate this response remain poorly understood. To get a better understanding of this, we used Drosophila melanogaster as a model, analyzing the transcriptional response of neural stem cells (neuroblasts) and glia of the blood-brain barrier (BBB) from larvae of both sexes during nutrient restriction using targeted DamID. We found differentially expressed genes in both neuroblasts and glia of the BBB, although the effect of nutrient deficiency was primarily observed in the BBB. We characterized the function of a nutritional sensitive gene expressed in the BBB, the serine protease homolog, scarface (scaf). Scaf is expressed in subperineurial glia in the BBB in response to nutrition. Tissue-specific knockdown of scaf increases subperineurial glia endoreplication and proliferation of perineurial glia in the blood-brain barrier. Furthermore, neuroblast proliferation is diminished on scaf knockdown in subperineurial glia. Interestingly, reexpression of Scaf in subperineurial glia is able to enhance neuroblast proliferation and brain growth of animals in starvation. Finally, we show that loss of scaf in the blood-brain barrier increases sensitivity to drugs in adulthood, suggesting a physiological impairment. We propose that Scaf integrates the nutrient status to modulate the balance between neurogenesis and growth of the BBB, preserving the proper equilibrium between the size of the barrier and the brain.SIGNIFICANCE STATEMENT The Drosophila BBB separates the CNS from the open circulatory system. The BBB glia are not only acting as a physical segregation of tissues but participate in the regulation of the metabolism and neurogenesis during development. Here we analyze the transcriptional response of the BBB glia to nutrient deprivation during larval development, a condition in which protective mechanisms are switched on in the brain. Our findings show that the gene scarface reduces growth in the BBB while promoting the proliferation of neural stem, assuring the balanced growth of the larval brain. Thus, Scarface would link animal nutrition with brain development, coordinating neurogenesis with the growth of the BBB
Hypothetical Reasoning via Provenance Abstraction
Data analytics often involves hypothetical reasoning: repeatedly modifying
the data and observing the induced effect on the computation result of a
data-centric application. Previous work has shown that fine-grained data
provenance can help make such an analysis more efficient: instead of a costly
re-execution of the underlying application, hypothetical scenarios are applied
to a pre-computed provenance expression. However, storing provenance for
complex queries and large-scale data leads to a significant overhead, which is
often a barrier to the incorporation of provenance-based solutions.
To this end, we present a framework that allows to reduce provenance size.
Our approach is based on reducing the provenance granularity using user defined
abstraction trees over the provenance variables; the granularity is based on
the anticipated hypothetical scenarios. We formalize the tradeoff between
provenance size and supported granularity of the hypothetical reasoning, and
study the complexity of the resulting optimization problem, provide efficient
algorithms for tractable cases and heuristics for others. We experimentally
study the performance of our solution for various queries and abstraction
trees. Our study shows that the algorithms generally lead to substantial
speedup of hypothetical reasoning, with a reasonable loss of accuracy
Big Data Analysis
The value of big data is predicated on the ability to detect trends and patterns and more generally to make sense of the large volumes of data that is often comprised of a heterogeneous mix of format, structure, and semantics. Big data analysis is the component of the big data value chain that focuses on transforming raw acquired data into a coherent usable resource suitable for analysis. Using a range of interviews with key stakeholders in small and large companies and academia, this chapter outlines key insights, state of the art, emerging trends, future requirements, and sectorial case studies for data analysis
High-quality EuO thin films the easy way via topotactic transformation
Epitaxy is widely employed to create highly oriented crystalline films. A less appreciated, butnonetheless powerful means of creating such films is via topotactic transformation, in which achemical reaction transforms a single crystal of one phase into a single crystal of a differentphase, which inherits its orientation from the original crystal. Topotactic reactions may beapplied to epitactic films to substitute, add or remove ions to yield epitactic films of differentphases. Here we exploit a topotactic reduction reaction to provide a non-ultra-high vacuum(UHV) means of growing highly oriented single crystalline thin films of the easily overoxidizedhalf-metallic semiconductor europium monoxide (EuO) with a perfection rivallingthat of the best films of the same material grown by molecular-beam epitaxy or UHV pulsedlaserdeposition. As the technique only requires high-vacuum deposition equipment, it hasthe potential to drastically improve the accessibility of high-quality single crystalline films ofEuO as well as other difficult-to-synthesize compounds
Reflective, polarizing, and magnetically soft amorphous Fe/Si multilayer neutron optics with isotope-enriched 11B4C inducing atomically flat interfaces
The utilization of polarized neutrons is of great importance in scientific
disciplines spanning materials science, physics, biology, and chemistry.
Polarization analysis offers insights into otherwise unattainable sample
information such as magnetic domains and structures, protein crystallography,
composition, orientation, ion-diffusion mechanisms, and relative location of
molecules in multicomponent biological systems. State-of-the-art multilayer
polarizing neutron optics have limitations, particularly low specular
reflectivity and polarization at higher scattering vectors/angles, and the
requirement of high external magnetic fields to saturate the polarizer
magnetization. Here, we show that by incorporating 11B4C into Fe/Si
multilayers, amorphization and smooth interfaces can be achieved, yielding
higher neutron reflectivity, less diffuse scattering and higher polarization.
Magnetic coercivity is eliminated, and magnetic saturation can be reached at
low external fields (>2 mT). This approach offers prospects for significant
improvement in polarizing neutron optics, enabling; nonintrusive positioning of
the polarizer, enhanced flux, increased data accuracy, and further
polarizing/analyzing methods at neutron scattering facilities
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