This paper contrasts the natural and anthropogenic controls on the conversion of unreactive N2 to more reactive forms of nitrogen (Nr). A variety of data sets are used to construct global N budgets for 1860 and the early 1990s and to make projections for the global N budget in 2050. Regional N budgets for Asia, North America, and other major regions for the early 1990s, as well as the marine N budget, are presented to highlight the dominant fluxes of nitrogen in each region. Important findings are that human activities increasingly dominate the N budget at the global and at most regional scales, the terrestrial and open ocean N budgets are essentially dis- connected, and the fixed forms of N are accumulating in most environmental reservoirs. The largest uncertainties in our understanding of the N budget at most scales are the rates of natural biological nitrogen fixation, the amount of Nr storage in most environmental reservoirs, and the production rates of N2 by denitrification.

/pdf/nitrogen-cycles-past-present-and-future-1zdbw0976r.pdf

Nitrogen cycles: past, present, and future

We report an improved draft nucleotide sequence of the 2.3-gigabase genome of maize, an important crop plant and model for biological research. Over 32,000 genes were predicted, of which 99.8% were placed on reference chromosomes. Nearly 85% of the genome is composed of hundreds of families of transposable elements, dispersed nonuniformly across the genome. These were responsible for the capture and amplification of numerous gene fragments and affect the composition, sizes, and positions of centromeres. We also report on the correlation of methylation-poor regions with Mu transposon insertions and recombination, and copy number variants with insertions and/or deletions, as well as how uneven gene losses between duplicated regions were involved in returning an ancient allotetraploid to a genetically diploid state. These analyses inform and set the stage for further investigations to improve our understanding of the domestication and agricultural improvements of maize.

/pdf/the-b73-maize-genome-complexity-diversity-and-dynamics-2hdsrsw8xl.pdf

The B73 Maize Genome: Complexity, Diversity, and Dynamics

We explore the development of the Anthropocene, the current epoch in which humans and our societies have become a global geophysical force. The Anthropocene began around 1800 with the onset of industrialization, the central feature of which was the enormous expansion in the use of fossil fuels. We use atmospheric carbon dioxide concentration as a single, simple indicator to track the progression of the Anthropocene. From a preindustrial value of 270-275 ppm, atmospheric carbon dioxide had risen to about 310 ppm by 1950. Since then the human enterprise has experienced a remarkable explosion, the Great Acceleration, with significant consequences for Earth System functioning. Atmospheric CO2 concentration has risen from 310 to 380 ppm since 1950, with about half of the total rise since the preindustrial era occurring in just the last 30 years. The Great Acceleration is reaching criticality. Whatever unfolds, the next few decades will surely be a tipping point in the evolution of the Anthropocene.

/pdf/the-anthropocene-are-humans-now-overwhelming-the-great-2zf4ui77b8.pdf

The Anthropocene: are humans now overwhelming the great forces of Nature?

Plants host distinct bacterial communities on and inside various plant organs, of which those associated with roots and the leaf surface are best characterized. The phylogenetic composition of these communities is defined by relatively few bacterial phyla, including Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria. A synthesis of available data suggests a two-step selection process by which the bacterial microbiota of roots is differentiated from the surrounding soil biome. Rhizodeposition appears to fuel an initial substrate-driven community shift in the rhizosphere, which converges with host genotype–dependent finetuning of microbiota profiles in the selection of root endophyte assemblages. Substrate-driven selection also underlies the establishment of phyllosphere communities but takes place solely at the immediate leaf surface. Both the leaf and root microbiota contain bacteria that provide indirect pathogen protection, but root microbiota members appear to serve additional host functions through the acquisition of nutrients from soil for plant growth. Thus, the plant microbiota emerges as a fundamental trait that includes mutualism enabled through diverse biochemical mechanisms, as revealed by studies on plant growth–promoting and plant health–promoting bacteria.

Structure and functions of the bacterial microbiota of plants

Vision for Transformation Strengths: The SHSIP describes a holistic transformation plan and ensures connections between various plan components. The State’s Plan seeks to reward health care providers for better care, smarter spending, and healthier people through higher quality, instead of quantity of services by utilizing valuebased purchasing across public and private payers. The SHSIP provides a well-detailed description of the proposed value-based models of care through the Patient-Centered Medical Home (PCMH) model, resulting in the statewide implementation of Accountable Health Communities (AHCs). The SHSIP outlines a long-term vision of building and expanding the PCMH model into a Community Centered Health Homes (CCHHs) model, which will focus on prevention and collaboration with other communitybased organizations. Another strength identified is the amount of existing PCMHs operating within the State. The SHSIP provides a course of action to assist non-PCMH practices to become nationally certified, as well as, goals for a single, statewide PCMH model to be used by all providers and payers within the state. The implementation of the AHCs will be key in addressing social determinants of health within various communities and seems to align well with the PCMH goals. This focus on population and community health will enable the State to make a broader impact and support the long-term goal of moving towards a CCHH model. The focus on the improvement of clinical, behavioral, and oral health care within the urban, rural, and frontier communities is well aligned and consistent with the SIM goals and the overall Triple Aim initiative. Figure 18: Driver Diagram clearly shows how the State plans to achieve the Triple Aim by 2020.

Department of health & human services

http://image.sciencenet.cn/olddata/kexue.com.cn/upload/blog/file/2008/8/20088317044836131.pdf

The Molecular Genetics of Crop Domestication

In search of origins creating new plants and animals new technology and the search for agricultural origins the fertile crescent Europe and Africa East Asia Middle and South America Eastern North America and the Southwest the search for explanations.

The Emergence of Agriculture

Societies with low-level food production economies occupy the vast and diverse middle ground between hunting–fishing–foraging and agriculture. Efforts by Ford, Harris, Rindos, Zvelebil, and others to characterize this “in-between” territory are discussed, and a new conceptual framework is proposed. Domestication, the central landmark of this middle ground, is situated well away from the boundaries with hunting–gathering and agriculture, and separates low-level food production economies into two broad categories. Key issues and questions concerning societies with low-level food production, both with and without domesticates, are discussed. Hunter–gatherer and agriculture boundary zones on either side of the middle ground are considered, as are the developmental pathways that traverse them.

http://web.clas.ufl.edu/users/davidson/Proseminar/Week%2014%20Subsistance/2001,%20Smith,%20Low%20Level%20food%20production.pdf

Low-Level Food Production

Previously unknown sufficient conditions, a necessary condition, and reconstruction methods for image reconstruction from cone-beam projections are developed. A sufficient condition developed is contained in the following statement. Statement 5: If one every plane that intersects the object, there exists at least one cone-beam source point, then the object can be reconstructed. Reconstruction methods for an arbitrary configuration of source points that satisfy Statement 5 are derived. By requiring additional conditions on the configuration of source points, a more efficient reconstruction method is developed. It is shown that when the configuration of source points is a circle, Statement 5 is not satisfied. In spite of this, several suggestions are made for reconstruction from a circle of source points.

Bruce D. Smith

Papers

The Molecular Genetics of Crop Domestication

The Emergence of Agriculture

Low-Level Food Production

Image Reconstruction from Cone-Beam Projections: Necessary and Sufficient Conditions and Reconstruction Methods

The onset of the Anthropocene