For example, China has launched national programs for soil testing and fertilizer recommendations since 2005. In 2009, 2,500 counties in China were involved in the programs, receiving a total of 1.5 billion yuan from the Chinese central government. Although the on-farm trials were conducted by local farmers in the same counties as the farmers’ surveys, the management and environment is not always the same for on-farm trials and farmers’ surveys. While gains in grain yield and GHG were achieved by farmers using the trials, we believe that the majority of these gains can be realized in practice in many counties if improved agronomic and N management techniques are adopted. The management and environment differed among four maize regions; thus, N losses may also differ. For example, the annual direct N2O emission accounted for 0.92% of the applied N with an uncertainty of 29%. The highest N2O fluxes occurred in East China as compared with the lowest fluxes in West China. In this study, we use the different exponential relationships of the N application rate and N2O fluxes for spring maize and summer maize, respectively. However, developing N loss models at the regional or subregional scale is difficult due to insufficient field measurement data in China. Longterm field observations covering all subregions are required to accurately assess farming potential and mitigate GHG emissions. In yeast, the NLE1 ortholog Rsa4 is essential for ribosome biogenesis. It assembles in the nucleolus with the pre-60S ribosomal subunit and interacts through its well-conserved amino-terminal region with the AAA-ATPase Rea1. This interaction is required for the disassembly of non-ribosomal factors prior to export of the mature large subunit to the cytoplasm. We recently showed that the key role of NLE1 in 60S biogenesis is conserved during evolution. Using conditional inactivation in adult mice, we demonstrated that NLE1 regulated ribosome biogenesis in hematopoietic stem cells and immature progenitors and was required for the maintenance of these populations. Strikingly, NLE1 was dispensable for ribosome biogenesis, proliferation and differentiation of B lymphocytes, suggesting that alternative pathways for 60S subunit production might exist and be differentially active depending on cell type or degree of differentiation. Limited data is available so far concerning the role of NLE1 during embryonic development. We previously reported that constitutive Nle1 inactivation leads to embryonic lethality around the time of implantation due to selective apoptosis of pluripotent cells of the blastocyst. Early embryonic lethality has recently been reported for mice homozygous for non-conservative missense Nle1 mutations obtained by ENU mutagenesis. The skin being the largest organ in our body, accounts for about 16% of the net body weight and serves as a barrier against various biological, mechanical, chemical and thermal injuries.