Lessons from a soil fertility laboratory

Non-Peer ReviewedA growth chamber experiment was established to demonstrate several basic principles of soil fertility to undergraduate students. Barley and field pea were grown in pots to demonstrate the effects of erosion and crop rotation on the yield potential and nitrogen response for two soils from the Brown soil zone. The results demonstrated differences in the ability of different crops to access nutrients, the effect of landscape position on nutrient availability and fertilizer response, and the ability of soil analytical tools like PRS to reveal differences in soil nutrient supplying power

Automated software distribution

Automated distribution of computer software via electronic means in large corporate networks is growing in popularity. The relative importance of personal computer software, in financial and logistical terms, is described and the developing need for automated software distribution explained. An actual comparitive example of alternative software distribution strategies is presented and discussed proving the viability of Electronic Software Distribution.Geoutomatiseerde verspreiding van rekenaarprogrammatuur met behulp van elektroniese metodes in groot korporatiewe netwerke, is toenemend populer, Die relatiewe belangrikheid van persoonlike rekenaarprogrammatuur in finansiele en logistieke terme word bespreek en die groeiende behoefte na geoutomatiseerde programmatuurverspreiding verduidelik. 'n Werklike vergelykende voorbeeld van alternatiewe programmatuurverspreidingsstrategiee word aangebied en bespreek wat die lewensvatbaarheid van Elektroniese Programmatuurverspreiding bewys.http://sajie.journals.ac.z

Lipogenesis and redox balance in nitrogen-fixing pea bacteroids

Within legume root nodules, rhizobia differentiate into bacteroids that oxidise host-derived dicarboxylic acids, which is assumed to occur via the TCA-cycle to generate NAD(P)H for reduction of N2. Metabolic flux analysis of laboratory grown Rhizobium leguminosarum showed that the flux from 13C-succinate was consistent with respiration of an obligate aerobe growing on a TCA-cycle intermediate as the sole carbon source. However, the instability of fragile pea bacteroids prevented their steady state labelling under N2-fixing conditons. Therefore, comparitive metabolomic profiling was used to compare free-living R. leguminosarum with pea bacteroids. While the TCA-cycle was shown to be essential for maximal rates of N2-fixation, pyruvate (5.5-fold down), acetyl-CoA (50-fold down), free coenzyme A (33-fold) and citrate (4.5-fold down) were much lower in bacteroids. Instead of completely oxidising acetyl-CoA, pea bacteroids channel it into both lipid and the lipid-like polymer poly-β-hydroxybutyrate (PHB), the latter via a type II PHB synthase that is only active in bacteroids. Lipogenesis may be a fundamental requirement of the redox poise of electron donation to N2 in all legume nodules. Direct reduction by NAD(P)H of the likely electron donors for nitrogenase, such as ferredoxin, is inconsistent with their redox potentials. Instead, bacteroids must balance the production of NAD(P)H from oxidation of acetyl-CoA in the TCA-cycle with its storage in PHB and lipids

Feasibility of Electrified Propulsion for Ultra-Efficient Commercial Aircraft Final Report

MIT, Aurora Flight Sciences, and USC have collaborated to assess the feasibility of electric, hybridelectric, and turbo-electric propulsion for ultra-efficient commercial transportation. The work has drawn on the team expertise in disciplines related to aircraft design, propulsion-airframe integration, electric machines and systems, engineering system design, and optimization. A parametric trade space analysis has been carried out to assess vehicle performance across a range of transport missions and propulsion architectures to establish how electrified propulsion systems scale. An optimization approach to vehicle conceptual design modeling was taken to enable rapid multidisciplinary design space exploration and sensitivity analysis. The results of the analysis indicate vehicle aero-propulsive integration benefits enabled by electrification are required to offset the increased weight and loss associated with the electric system and achieve enhanced performance; the report describes the conceptual configurations than can offer such enhancements. The main contribution of the present work is the definition of electric vehicle design attributes for potential efficiency improvements at different scales. Based on these results, key areas for future research are identified, and extensions to the trade space analysis suitable for higher fidelity electrified commercial aircraft design and analysis have been developed

B_s --> mu+ mu- decay in the R-parity violating minimal supergravity

We study B_s --> mu+ mu- in the context of the R-parity violating minimal supergravity in the high tan beta regime. We find that the lowest value of the branching ratio can go well below the present LHCb sensitivity and hence B_s --> mu+ mu- can even be invisible to the LHC. We also find that the present upper bound on Br(B_s --> mu+ mu-) puts strong constraint on the minimal supergravity parameter space. The constraints become more severe if the upper bound is close to its standard model prediction.Comment: 18 pages, 10 figures; version to be published in European Physical Journal

Microbial interactions with phosphorus containing glasses representative of vitrified radioactive waste

The presence of phosphorus in borosilicate glass (at 0.1 – 1.3 mol% P2O5) and in iron-phosphate glass (at 53 mol% P2O5) stimulated the growth and metabolic activity of anaerobic bacteria in model systems. Dissolution of these phosphorus containing glasses was either inhibited or accelerated by microbial metabolic activity, depending on the solution chemistry and the glass composition. The breakdown of organic carbon to volatile fatty acids increased glass dissolution. The interaction of microbially reduced Fe(II) with phosphorus-containing glass under anoxic conditions decreased dissolution rates, whereas the interaction of Fe(III) with phosphorus-containing glass under oxic conditions increased glass dissolution. Phosphorus addition to borosilicate glasses did not significantly affect the microbial species present, however, the diversity of the microbial community was enhanced on the surface of the iron phosphate glass. Results demonstrate the potential for microbes to influence the geochemistry of radioactive waste disposal environments with implication for wasteform durability

Forty years of durability assessment of nuclear waste glass by standard methods

Standard methods to assess the durability of vitrified radioactive waste were first developed in the 1980’s and, over the last 40 years, have evolved to yield a range of responses depending on experimental conditions and glass composition. Mechanistic understanding of glass dissolution has progressed in parallel, enhancing our interpretation of the data acquired. With the implementation of subsurface disposal for vitrified radioactive waste drawing closer, it is timely to review the available standard methodologies and reflect upon their relative advantages, limitations, and how the data obtained can be interpreted to support the post-closure safety case for radioactive waste disposal

Infrastructure for Detector Research and Development towards the International Linear Collider

The EUDET-project was launched to create an infrastructure for developing and testing new and advanced detector technologies to be used at a future linear collider. The aim was to make possible experimentation and analysis of data for institutes, which otherwise could not be realized due to lack of resources. The infrastructure comprised an analysis and software network, and instrumentation infrastructures for tracking detectors as well as for calorimetry.Comment: 54 pages, 48 picture

Applying laboratory methods for durability assessment of vitrified material to archaeological samples

Laboratory testing used to assess the long-term chemical durability of nuclear waste forms may not be applicable to disposal because the accelerated conditions may not represent disposal conditions. To address this, we examine the corrosion of vitrified archeological materials excavated from the near surface of a ~1500-year old Iron Age Swedish hillfort, Broborg, as an analog for the disposal of vitrified nuclear waste. We compare characterized site samples with corrosion characteristics generated by standard laboratory durability test methods including the product consistency test (PCT), the vapor hydration test (VHT), and the EPA Method 1313 test. Results show that the surficial layer of the Broborg samples resulting from VHT displays some similarities to the morphology of the surficial layer formed over longer timescales in the environment. This work provides improved understanding of long-term glass corrosion behavior in terms of the thickness, morphology, and chemistry of the surficial features that are formed

Hematopoietic stem cell transplantation in a patient with proteasome-associated autoinflammatory syndrome (PRAAS)

Background: Proteasome-associated autoinflammatory syndromes (PRAASs) form a family of recently described rare autosomal recessive disorders of disturbed proteasome assembly and proteolytic activity caused by mutations in genes coding for proteasome subunits. The treatment options for these proteasome disorders consist of lifelong immunosuppressive drugs or Janus kinase inhibitors, which may have partial efficacy and noticeable side effects. Because proteasomes are ubiquitously expressed, it is unknown whether hematopoietic stem cell transplantation (HSCT) may be a sufficient treatment option. Objective: Our aim was to report the case of a young boy with a treatment-resistant cutaneous vasculitis that was initially suspected to be associated with a gene variant in SH2D1A. Methods: Whole-exome sequencing was performed to identify the genetic defect. Molecular and functional analyses were performed to assess the impact of variants on proteasomal function. The immune characterization led to the decision to perform HSCT on our patient and conduct follow-up over the 7-year period after the transplant. Because loss of myeloid chimerism after the first HSCT was associated with relapse of autoinflammation, a second HSCT was performed. Results: After the successful second HSCT, the patient developed mild symptoms of lipodystrophy, which raised the suspicion of a PRAAS. Genetic analysis revealed 2 novel heterozygous variants in PSMB4 (encoding proteasomal subunit beta 7). Retrospective analysis of patient cells stored before the first HSCT and patient cells obtained after the second HSCT demonstrated that HSCT successfully rescued proteasome function, restored protein homeostasis, and resolved the interferon-stimulated gene signature. Furthermore, successful HSCT alleviated the autoinflammatory manifestations in our patient. Conclusion: Patients with treatment-resistant PRAAS can be cured by HSCT.Transplantation and immunomodulatio