An assembler and disassembler framework for Java™ programmers

AbstractThe Java™ programming language is primarily used for platform-independent programming. Yet it also offers many productivity, maintainability and performance benefits for platform-specific functions, such as the generation of machine code.We have created reliable assemblers for SPARC™ , AMD64, IA32 and PowerPC which support all user mode and privileged instructions and with 64 bit mode support for all but the latter. These assemblers are generated as Java source code by our extensible assembler framework, which itself is written in the Java language. The assembler generator also produces javadoc comments that precisely specify the legal values for each operand.Our design is based on the Klein Assembler System written in Self. Assemblers are generated from a specification, as are table-driven disassemblers and unit tests. The specifications that drive the generators are expressed as Java language objects. Thus no extra parsers are needed and developers do not need to learn any new syntax to extend the framework for additional ISAs.Every generated assembler is tested against a preexisting assembler by comparing the output of both. Each instruction’s test cases are derived from the cross product of its potential operand values. The majority of tests are positive (i.e., result in a legal instruction encoding). The framework also generates negative tests, which are expected to cause an error detection by an assembler. As with the Klein Assembler System, we have found bugs in the external assemblers as well as in ISA reference manuals.Our framework generates tens of millions of tests. For symbolic operands, our tests include all applicable predefined constants. For integral operands, the important boundary values, such as the respective minimum, maximum, 0, 1 and −1, are tested. Full testing can take hours to run but gives us a high degree of confidence regarding correctness

Salt Induces Features of a Dormancy-Like State in Seeds of Eutrema (Thellungiella) salsugineum, a Halophytic Relative of Arabidopsis

[EN] The salinization of land is a major factor limiting crop production worldwide. Halophytes adapted to high levels of salinity are likely to possess useful genes for improving crop tolerance to salt stress. In addition, halophytes could provide a food source on marginal lands. However, despite halophytes being salt-tolerant plants, the seeds of several halophytic species will not germinate on saline soils. Yet, little is understood regarding biochemical and gene expression changes underlying salt-mediated inhibition of halophyte seed germination. We have used the halophytic Arabidopsis relative model system, Eutrema (Thellungiella) salsugineum to explore salt-mediated inhibition of germination. We show that E. salsugineum seed germination is inhibited by salt to a far greater extent than in Arabidopsis, and that this inhibition is in response to the osmotic component of salt exposure. E. salsugineum seeds remain viable even when germination is completely inhibited, and germination resumes once seeds are transferred to non-saline conditions. Moreover, removal of the seed coat from salt treated seeds allows embryos to germinate on salt-containing medium. Mobilization of seed storage reserves is restricted in salt treated seeds, while many germination associated metabolic changes are arrested or progress to a lower extent. Salt-exposed seeds are further characterized by a reduced GA/ABA ratio and increased expression of the germination repressor genes, RGL2,AB15, and DOG1. Furthermore, a salt-mediated increase in expression of a LATE EMBRYOGENESIS ABUNDANT gene and accretion of metabolites involved in osmoprotection indicates induction of processes associated with stress tolerance, and accumulation of easily mobilized carbon reserves. Overall, our results suggest that salt inhibits E. salsugineum seed germination by inducing a seed state with molecular features of dormancy while a physical constraint to radicle emergence is provided by the seed coat layers. This seed state could facilitate survival on saline soils until a rain event(s) increases soil water potential indicating favorable conditions for seed germination and establishment of salt-tolerant E. salsugineum seedlings.We would like to thank Ruti Shaked, and Noga Sikron for excellent technical help. This work was supported by the I-CORE Program of the Planning and Budgeting Committee and The Israel Science Foundation (grant no. 152/11 to SB), The Pearlstein Foundation (to AF), and the Center for Absorption in Science, Israel Ministry of Immigrant Absorption Grant (to YK).Kazachkova, Y.; Khan, A.; Acuña, T.; Lopez Diaz, I.; Carrera Bergua, E.; Khozin-Goldberg, I.; Fait, A.... (2016). Salt Induces Features of a Dormancy-Like State in Seeds of Eutrema (Thellungiella) salsugineum, a Halophytic Relative of Arabidopsis. Frontiers in Plant Science. 7(1071):1-18. https://doi.org/10.3389/fpls.2016.01071S1187107

Science and Measurement Requirements for a Plant Physiology and Functional Types Mission: Measuring the Composition, Function and Health of Global Land and Coastal Ocean Ecosystems

This slide presentation reviews the proposed Plant Physiology and Functional Types (PPFT) Mission. The National Academy of Sciences Decadal Survey, placed a critical priority on a Mission to observe distribution and changes in ecosystem functions. The PPFT satellite mission provides the essential measurements needed to assess drivers of change in biodiversity and ecosystem services that affect human welfare. The presentation reviews the science questions that the mission will be designed to answer, the science rationale, the science measurements, the mission concept, the planned instrumentation, the calibration method, and key signal to noise ratios and uniformity requirements