4,007 research outputs found
Solid-State Fermentation of Soybean and Corn Processing Coproducts for Potential Feed Improvement
Two agro-industrial coproducts, soybean cotyledon fiber and distiller’s dried grains with solubles (DDGS), were used as substrates to evaluate the effect of coculturing three different fungi, Aspergillus oryzae, Trichoderma reesei, and Phanerochaete chrysosporium, on enzyme production by solid-state fermentation (SSF). When soybean fiber was used as the substrate, a maximum xylanase activity of 757.4 IU/g and a cellulase activity of 3.2 IU/g were achieved with the inoculation and incubation of T. reesei and P. chrysosporium for 36 h, followed by A. oryzae for an additional 108 h. This inoculation scheme also resulted in the highest xylanase activity of 399.2 IU/g compared to other fungi combinations in the SSF of DDGS. A large-scale SSF by this fungus combination produced fermented products that had xylanase and cellulase activities of 35.9–57.0 and 0.4–1.2 IU/g, respectively. These products also had 3.5–15.1% lower fiber and 1.3–4.2% higher protein contents, suggesting a potential feed quality improvement
Functional Mapping of Multiple Dynamic Traits
Many biological phenomena undergo developmental changes in time and space.
Functional mapping, which is aimed at mapping genes that affect developmental
patterns, is instrumental for studying the genetic architecture of biological
changes. Often biological processes are mediated by a network of developmental
and physiological components and, therefore, are better described by multiple
phenotypes. In this article, we develop a multivariate model for functional
mapping that can detect and characterize quantitative trait loci (QTLs) that
simultaneously control multiple dynamic traits. Because the true genotypes of
QTLs are unknown, the measurements for the multiple dynamic traits are modeled
using a mixture distribution. The functional means of the multiple dynamic
traits are estimated using the nonparametric regression method, which avoids
any parametric assumption on the functional means. We propose the profile
likelihood method to estimate the mixture model. A likelihood ratio test is
exploited to test for the existence of pleiotropic effects on distinct but
developmentally correlated traits. A simulation study is implemented to
illustrate the finite sample performance of our proposed method. We also
demonstrate our method by identifying QTLs that simultaneously control three
dynamic traits of soybeans. The three dynamic traits are the time-course
biomass of the leaf, the stem, and the root of the whole soybean. The genetic
linkage map is constructed with 950 microsatellite markers. The new model can
aid in our comprehension of the genetic control mechanisms of complex dynamic
traits over time
Results of REXUS12's Suaineadh Experiment : Deployment of a spinning space web in micro gravity conditions
On the 19th of March 2012, the Suaineadh experiment was launched onboard the sounding rocket REXUS12 (Rocket Experiments for University Students) from the Swedish launch base ESRANGE in Kiruna. The Suaineadh experiment served as a technology demonstrator for a space web deployed by a spinning assembly. The deployment of this web is a stepping stone for the development of ever larger structures in space. Such a structure could serve as a substructure for solar arrays, transmitters and/or antennas. The team was comprised of students from the University of Strathclyde (Glasgow, UK), the University of Glasgow (Glasgow, UK) and the Royal Institute of Technology (Stockholm, Sweden), designing, manufacturing and testing the experiment over the past 24 months. Following launch, the experiment was ejected from the ejection barrel located within the nosecone of the rocket. Centrifugal forces acting upon the space webs spinning assembly were used to stabilise the experiment’s platform. A specifically designed spinning reaction wheel, with an active control method, was used. Once the experiment’s motion was controlled, a 2 m by 2 m space web is released. Four daughter sections situated in the corners of the square web served as masses to stabilise the web due to the centrifugal forces acting on them. The four daughter sections contained inertial measurement units (IMUs). Each IMU provided acceleration and velocity measurements in all three directions. Through this, the positions of the four corners could be found through integration with respect to known time of the accelerations and rotations. Furthermore, four cameras mounted on the central hub section captured high resolution imagery of the deployment process. After the launch of REXUS12, the recovery helicopter was unable to locate the ejected experiment, but 22 pictures were received over the wireless connection between the experiment and the rocket. The last received picture was taken at the commencement of web deployment. Inspection of these pictures allowed the assumption that the experiment was fully functional after ejection, but perhaps through tumbling of either the experiment or the rocket, the wireless connection was interrupted. A recovery mission in the middle of August was only able to find the REXUS12 motor and the payload impact location
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