Evaluating the performance of PC-ANN for the estimation of rice nitrogen concentration from canopy hyperspectral reflectance

In this study, a wide range of leaf nitrogen concentration levels was established in field-grown rice with the application of three fertilizer levels. Hyperspectral reflectance data of the rice canopy through rice whole growth stages were acquired over the 350 nm to 2500 nm range. Comparisons of prediction power of two statistical methods (linear regression technique (LR) and artificial neural network (ANN)), for rice N estimation (nitrogen concentration, mg nitrogen g(-1) leaf dry weight) were performed using two different input variables (nitrogen sensitive hyperspectral reflectance and principal component scores). The results indicted very good agreement between the observed and the predicted N with all model methods, which was especially true for the PC-ANN model (artificial neural network based on principal component scores), with an RMSE 0.347 and REP 13.14%. Compared to the LR algorithm, the ANN increased accuracy by lowering the RMSE by 17.6% and 25.8% for models based on spectral reflectance and PCs, respectively

Hypothalamic CaMKK2 Contributes to the Regulation of Energy Balance

SummaryDetailed knowledge of the pathways by which ghrelin and leptin signal to AMPK in hypothalamic neurons and lead to regulation of appetite and glucose homeostasis is central to the development of effective means to combat obesity. Here we identify CaMKK2 as a component of one of these pathways, show that it regulates hypothalamic production of the orexigenic hormone NPY, provide evidence that it functions as an AMPKα kinase in the hypothalamus, and demonstrate that it forms a unique signaling complex with AMPKα and β. Acute pharmacologic inhibition of CaMKK2 in wild-type mice, but not CaMKK2 null mice, inhibits appetite and promotes weight loss consistent with decreased NPY and AgRP mRNAs. Moreover, the loss of CaMKK2 protects mice from high-fat diet-induced obesity, insulin resistance, and glucose intolerance. These data underscore the potential of targeting CaMKK2 as a therapeutic intervention

A Complete Analysis of HA and NA Genes of Influenza A Viruses

BACKGROUND: More and more nucleotide sequences of type A influenza virus are available in public databases. Although these sequences have been the focus of many molecular epidemiological and phylogenetic analyses, most studies only deal with a few representative sequences. In this paper, we present a complete analysis of all Haemagglutinin (HA) and Neuraminidase (NA) gene sequences available to allow large scale analyses of the evolution and epidemiology of type A influenza. METHODOLOGY/PRINCIPAL FINDINGS: This paper describes an analysis and complete classification of all HA and NA gene sequences available in public databases using multivariate and phylogenetic methods. CONCLUSIONS/SIGNIFICANCE: We analyzed 18,975 HA sequences and divided them into 280 subgroups according to multivariate and phylogenetic analyses. Similarly, we divided 11,362 NA sequences into 202 subgroups. Compared to previous analyses, this work is more detailed and comprehensive, especially for the bigger datasets. Therefore, it can be used to show the full and complex phylogenetic diversity and provides a framework for studying the molecular evolution and epidemiology of type A influenza virus. For more than 85% of type A influenza HA and NA sequences into GenBank, they are categorized in one unambiguous and unique group. Therefore, our results are a kind of genetic and phylogenetic annotation for influenza HA and NA sequences. In addition, sequences of swine influenza viruses come from 56 HA and 45 NA subgroups. Most of these subgroups also include viruses from other hosts indicating cross species transmission of the viruses between pigs and other hosts. Furthermore, the phylogenetic diversity of swine influenza viruses from Eurasia is greater than that of North American strains and both of them are becoming more diverse. Apart from viruses from human, pigs, birds and horses, viruses from other species show very low phylogenetic diversity. This might indicate that viruses have not become established in these species. Based on current evidence, there is no simple pattern of inter-hemisphere transmission of avian influenza viruses and it appears to happen sporadically. However, for H6 subtype avian influenza viruses, such transmissions might have happened very frequently and multiple and bidirectional transmission events might exist

Lineage diversification and historical demography of a montane bird Garrulax elliotii - implications for the Pleistocene evolutionary history of the eastern Himalayas

<p>Abstract</p> <p>Background</p> <p>Pleistocene climate fluctuations have shaped the patterns of genetic diversity observed in many extant species. In montane habitats, species' ranges may have expanded and contracted along an altitudinal gradient in response to environmental fluctuations leading to alternating periods of genetic isolation and connectivity. Because species' responses to climate change are influenced by interactions between species-specific characteristics and local topography, diversification pattern differs between species and locations. The eastern Himalayas is one of the world's most prominent mountain ranges. Its complex topography and environmental heterogeneity present an ideal system in which to study how climatic changes during Pleistocene have influenced species distributions, genetic diversification, and demography. The Elliot's laughing thrush (<it>Garrulax elliotii</it>) is largely restricted to high-elevation shrublands in eastern Himalayas. We used mitochondrial DNA and microsatellites to investigate how genetic diversity in this species was affected by Pleistocene glaciations.</p> <p>Results</p> <p>Mitochondrial data detected two partially sympatric north-eastern and southern lineages. Microsatellite data, however, identified three distinct lineages congruent with the geographically separated southern, northern and eastern eco-subregions of the eastern Himalayas. Geographic breaks occur in steep mountains and deep valleys of the Kangding-Muli-Baoxin Divide. Divergence time estimates and coalescent simulations indicate that lineage diversification occurred on two different geographic and temporal scales; recent divergence, associated with geographic isolation into individual subregions, and historical divergence, associated with displacement into multiple refugia. Despite long-term isolation, genetic admixture among these subregional populations was observed, indicating historic periods of connectivity. The demographic history of <it>Garrulax elliotii </it>shows continuous population growth since late Pleistocene (about 0.125 mya).</p> <p>Conclusion</p> <p>While altitude-associated isolation is typical of many species in other montane regions, our results suggest that eco-subregions in the eastern Himalayas exhibiting island-like characteristics appear to have determined the diversification of <it>Garrulax elliotii</it>. During the Pleistocene, these populations became isolated on subregions during interglacial periods but were connected when these expanded to low altitude during cooler periods. The resultant genetic admixture of lineages might obscure pattern of genetic variation. Our results provide new insights into sky island diversification in a previously unstudied region, and further demonstrate that Pleistocene climatic changes can have profound effects on lineage diversification and demography in montane species.</p

Optical properties of Au-Hf thin films

The optical properties of thin films of intermetallic Au$_{3}$Hf were experimentally investigated for the first time, which display clear plasmonic properties in the optical and near infrared region with negative permittivity. In contrast to similar alloys, such as films of Au$_{3}$Zr, the films express more negative $\epsilon'$ values and lower $\epsilon''$ values across most of the wavelengths (370-1570 nm) investigated. The Au$_{3}$Hf films were fabricated by DC magnetron sputtering at a range of deposition temperatures, from room temperature to 415$^{o}$C, and annealed at different vacuum levels. The films mostly formed as a combination of Au$_{3}$Hf, Au$_{2}$Hf and Au$_{4}$Hf phases when deposited below 400$^{o}$C, and exclusively Au$_{3}$Hf phase at above 400$^{o}$C, indicating key conditions for isolating this phase. The films were stable when annealed at 10$^{-8}$ Torr, but when annealed again at 10$^{-6}$ Torr the films oxidised and changed into a mix of Au- Hf phases, suggesting resistance to oxidization may be an issue for un-encapsulated applications at elevated temperatures.Comment: 19 pages, including references, plus 3 pages of supplementary material. 8 figures and 1 table in main text, 1 figure and 1 table in supplementary materia