A comparison of methods for early prediction of anaerobic biogas potential on biologically treated municipal solid waste

Anaerobic gas production tests, generically Biochemical Methane Potential (BMP) or Biogas Potential (BP) tests, are often used to assess biodegradability, though long duration limits their utility. This research investigated whether simple modelling approaches could provide a reliable earlier prediction of total biogas production. Data were assessed from a non-automated biogas test on a large number of both fresh and processed municipal solid waste (MSW) samples, sourced from a mechanical biological treatment (MBT) plant. Non-linear models of biogas production curves were useful in identifying a suitable test endpoint, supporting a test duration of 50 days. Biogas production at 50 days (B50) was predicted using the first 14 days of test data, using (a) linear correlation, (b) a new linearisation process, and (c) non-linear kinetic models. Prediction errors were quantified as relative root mean squared error of prediction (rRMSEP), and bias. Predictions from most models were improved by removing the initial exponential increase phase. Linear correlation gave the most precise and accurate predictions at 14 days (rRMSEP = 2.8%, bias under 0.05%) and allowed acceptable prediction (rRMSEP 50. These results demonstrate that early prediction of anaerobic gas production is possible for a well-optimised test, using only basic equipment and without recourse to external data sources or complex mathematical modelling

Aspartame in conjunction with carbohydrate reduces insulin levels during endurance exercise

Gold OAAs most sport drinks contain some form of non-nutritive sweetener (e.g. aspartame), and with the variation in blood glucose regulation and insulin secretion reportedly associated with aspartame, a further understanding of the effects on insulin and blood glucose regulation during exercise is warranted. Therefore, the aim of this preliminary study was to profile the insulin and blood glucose responses in healthy individuals after aspartame and carbohydrate ingestion during rest and exercise. Each participant completed four trials under the same conditions (45 min rest + 60 min self-paced intense exercise) differing only in their fluid intake: 1) carbohydrate (2% maltodextrin and 5% sucrose (C)); 2) 0.04% aspartame with 2% maltodextrin and 5% sucrose (CA)); 3) water (W); and 4) aspartame (0.04% aspartame with 2% maltodextrin (A)). Insulin levels dropped significantly for CA versus C alone (43%) between pre-exercise and 30 min, while W and A insulin levels did not differ between these time points. Aspartame with carbohydrate significantly lowered insulin levels during exercise versus carbohydrate alone.Peer Reviewe

Molecular cytogenetic differentiation of paralogs of Hox paralogs in duplicated and re-diploidized genome of the North American paddlefish (Polyodon spathula).

BackgroundAcipenseriformes is a basal lineage of ray-finned fishes and comprise 27 extant species of sturgeons and paddlefishes. They are characterized by several specific genomic features as broad ploidy variation, high chromosome numbers, presence of numerous microchromosomes and propensity to interspecific hybridization. The presumed palaeotetraploidy of the American paddlefish was recently validated by molecular phylogeny and Hox genes analyses. A whole genome duplication in the paddlefish lineage was estimated at approximately 42 Mya and was found to be independent from several genome duplications evidenced in its sister lineage, i.e. sturgeons. We tested the ploidy status of available chromosomal markers after the expected rediploidization. Further we tested, whether paralogs of Hox gene clusters originated from this paddlefish specific genome duplication are cytogenetically distinguishable.ResultsWe found that both paralogs HoxA alpha and beta were distinguishable without any overlapping of the hybridization signal - each on one pair of large metacentric chromosomes. Of the HoxD, only the beta paralog was unequivocally identified, whereas the alpha paralog did not work and yielded only an inconclusive diffuse signal. Chromosomal markers on three diverse ploidy levels reflecting different stages of rediploidization were identified: quadruplets retaining their ancestral tetraploid condition, semi-quadruplets still reflecting the ancestral tetraploidy with clear signs of advanced rediploidization, doublets were diploidized with ancestral tetraploidy already blurred. Also some of the available microsatellite data exhibited diploid allelic band patterns at their loci whereas another locus showed more than two alleles.ConclusionsOur exhaustive staining of paddlefish chromosomes combined with cytogenetic mapping of ribosomal genes and Hox paralogs and with microsatellite data, brings a closer look at results of the process of rediploidization in the course of paddlefish genome evolution. We show a partial rediploidization represented by a complex mosaic structure comparable with segmental paleotetraploidy revealed in sturgeons (Acipenseridae). Sturgeons and paddlefishes with their high propensity for whole genome duplication thus offer suitable animal model systems to further explore evolutionary processes that were shaping the early evolution of all vertebrates

Evaluation of Operation IceBridge quick-look snow depth estimates on sea ice

We evaluate Operation IceBridge (OIB) ‘quick-look’ (QL) snow depth on sea ice retrievals using in situ measurements taken over immobile first-year ice (FYI) and multi-year ice (MYI) during March of 2014. Good agreement was found over undeformed FYI (-4.5 cm mean bias) with reduced agreement over deformed FYI (-6.6 cm mean bias). Over MYI, the mean bias was -5.7 cm but 54% of retrievals were discarded by the OIB retrieval process as compared to only 10% over FYI. Footprint scale analysis revealed a root mean square error (RMSE) of 6.2 cm over undeformed FYI with RMSE of 10.5 cm and 17.5 cm in the more complex deformed FYI and MYI environments. Correlation analysis was used to demonstrate contrasting retrieval uncertainty associated with spatial aggregation and ice surface roughness

Specialized Middle Level Teacher Preparation: Moving From Advocacy to Actualization

Is specialized middle level teacher preparation necessary? This essay offers the authors thoughts regarding middle level teaching and the necessity of specialized middle level teacher preparation. The reader is encouraged to further the discussion of middle level teacher preparation from advocacy to actualization

Middle Level Teacher Preparation: Principals’ Perceptions of New Teacher Preparedness--RESEARCH

Drawing on the Framework for Effective Middle Level Teaching(Faulkner, Howell, &Cook, 2012; Howell, Cook, Faulkner, 2013), this interpretive, exploratory study utilized survey methodology to analyze 38 middle level principals’ perceptions of effective teaching practices and the preparedness of newly hired middle level teachers. The findings suggest there is difference in perceptions of new teacher preparedness between principals with middle level teacher certification and principals that were prepared to teach at other grade levels. While both groups acknowledged the need for better teacher preparation, principals with middle level teacher certification reported that newly hired teachers were less prepared for effective middle level teaching. The researchers identified two primary conclusions that impact the field of middle grades teacher preparation: (a) beginning middle grades teachers need to be better prepared for effective teaching and (b) principals perceive the preparation of new teachers differently depending upon their own teaching certification, with principals holding middle grades teaching certification being more critical of the level of preparation. While both strengths and weaknesses of preparation were identified in each of the six constructs, the most relevant and important conclusion is that middle level principals perceive beginning middle grades teachers as not being adequately prepared to address the demands of effective middle grades teaching in several constructs from the Framework for Effective Middle Level Teaching

The Near-Earth Space Radiation Environment During Solar Cycle 25: Consequences for the Alabama Burst Energetics eXplorer

The Alabama Burst Energetics eXplorer (ABEX) is a 12U mission to enhance the detection of low energy Gamma Ray Burst (GRB) components and provide improved, rapid localization of short GRBs for multiwavelength follow up via GRB measurements outside the Van Allen Belts (VAB). The ABEX launch date is Q4 2024 during the peak of solar cycle 25; the ABEX science orbit is 300 km perigee by 60,000 km apogee with an inclination of 27°. This orbit defines distinct radiation environments in Low Earth Orbit, crossing the VABs, performing science operations outside the VABs, and Coronal Mass Ejection (CME) conditions. Numerical trajectory data was generated in AGI’s Systems Tool Kit and provided to the Space Environment Information System (SPENVIS). VAB trapped particle, Solar Energetic Particle, and Galactic Cosmic Ray particle fluxes were determined for the ABEX orbit. Empirical fits for Total Ionizing Dose are provided per particle source. Solar cell degradation as a function of Non-Ionizing Energy Loss was calculated per coverglass thickness with mass implications. Charged Particle Heating is characterized in a full thermal radiation model. Single Event Effects and surface charging are not discussed in the context of particle flux

Applications of Multi-Body Dynamical Environments: The ARTEMIS Transfer Trajectory Design

The application of forces in multi-body dynamical environments to pennit the transfer of spacecraft from Earth orbit to Sun-Earth weak stability regions and then return to the Earth-Moon libration (L1 and L2) orbits has been successfully accomplished for the first time. This demonstrated transfer is a positive step in the realization of a design process that can be used to transfer spacecraft with minimal Delta-V expenditures. Initialized using gravity assists to overcome fuel constraints; the ARTEMIS trajectory design has successfully placed two spacecraft into EarthMoon libration orbits by means of these applications