Vinogradov's mean value theorem via efficient congruencing

We obtain estimates for Vinogradov's integral which for the first time approach those conjectured to be the best possible. Several applications of these new bounds are provided. In particular, the conjectured asymptotic formula in Waring's problem holds for sums of s kth powers of natural numbers whenever s is at least 2k^2+2k-3

Advances in biodiversity: metagenomics and the unveiling of biological dark matter

BACKGROUND: Efforts to harmonize genomic data standards used by the biodiversity and metagenomic research communities have shown that prokaryotic data cannot be understood or represented in a traditional, classical biological context for conceptual reasons, not technical ones. RESULTS: Biology, like physics, has a fundamental duality—the classical macroscale eukaryotic realm vs. the quantum microscale microbial realm—with the two realms differing profoundly, and counter-intuitively, from one another. Just as classical physics is emergent from and cannot explain the microscale realm of quantum physics, so classical biology is emergent from and cannot explain the microscale realm of prokaryotic life. Classical biology describes the familiar, macroscale realm of multi-cellular eukaryotic organisms, which constitute a highly derived and constrained evolutionary subset of the biosphere, unrepresentative of the vast, mostly unseen, microbial world of prokaryotic life that comprises at least half of the planet’s biomass and most of its genetic diversity. The two realms occupy fundamentally different mega-niches: eukaryotes interact primarily mechanically with the environment, prokaryotes primarily physiologically. Further, many foundational tenets of classical biology simply do not apply to prokaryotic biology. CONCLUSION: Classical genetics one held that genes, arranged on chromosomes like beads on a string, were the fundamental units of mutation, recombination, and heredity. Then, molecular analysis showed that there were no fundamental units, no beads, no string. Similarly, classical biology asserts that individual organisms and species are fundamental units of ecology, evolution, and biodiversity, composing an evolutionary history of objectively real, lineage-defined groups in a single-rooted tree of life. Now, metagenomic tools are forcing a recognition that there are no completely objective individuals, no unique lineages, and no one true tree. The newly revealed biosphere of microbial dark matter cannot be understood merely by extending the concepts and methods of eukaryotic macrobiology. The unveiling of biological dark matter is allowing us to see, for the first time, the diversity of the entire biosphere and, to paraphrase Darwin, is providing a new view of life. Advancing and understanding that view will require major revisions to some of the most fundamental concepts and theories in biology

The appraisal of farm buildings

Caption title.Digitized 2006 AES MoU

Cylindabot: Transformable Wheg Robot Traversing Stepped and Sloped Environments

The ability of an autonomous robot to adapt to different terrain affords the flexibility to move successfully in a range of environments. This paper proposes the Cylindabot, a transformable Wheg robot that can move with two large wheels, each of which can rotate out, producing three legs. This ability to change its mode of locomotion allows for specialised performance. The Cylindabot has been tested in simulation and on a physical robot on steps and slopes as an indication of its efficacy in different environments. These experiments show that such robots are capable of climbing up to a 32 degree slope and a step 1.43 times their initial height. Theoretical limits are devised that match the results, and a comparison with existing Wheg platforms is made

Book Reviews

Book reviews of the following: Urban Design and the Bottom Line: Optimizing the Return on Perception by Dennis Jerke, Douglas R. Porter, and Terry J. Lassar; A Paradise Built in Hell by Rebecca Solnit; Edible Estates: Attack on the Front Lawn by Fritz Hae

The Missouri soil saving dam : low-cost structure for use in farm plans for water management

Cover title."A revision of Bulletin 434" -- P. [3]

The Missouri soil saving dam : low-cost structure for use in farm plans for water management

Cover title

Restrictions Limiting the Generation of DNA Double Strand Breaks during Chromosomal V(D)J Recombination

Antigen receptor loci are composed of numerous variable (V), diversity (D), and joining (J) gene segments, each flanked by recombination signal sequences (RSSs). The V(D)J recombination reaction proceeds through RSS recognition and DNA cleavage steps making it possible for multiple DNA double strand breaks (DSBs) to be introduced at a single locus. Here we use ligation-mediated PCR to analyze DNA cleavage intermediates in thymocytes from mice with targeted RSS mutations at the endogenous TCRβ locus. We show that DNA cleavage does not occur at individual RSSs but rather must be coordinated between RSS pairs flanking gene segments that ultimately form coding joins. Coordination of the DNA cleavage step occurs over great distances in the chromosome and favors intra- over interchromosomal recombination. Furthermore, through several restrictions imposed on the generation of both nonpaired and paired DNA DSBs, this requirement promotes antigen receptor gene integrity and genomic stability in developing lymphocytes undergoing V(D)J recombination