Comparison of algorithms for incoming atmospheric long-wave radiation

While numerous algorithms exist for predicting incident atmospheric long-wave radiation under clear (Lclr) and cloudy skies, few comparisons have been published to assess the accuracy of the different algorithms. Virtually no comparisons have been made for both clear and cloudy skies across multiple sites. This study evaluates the accuracy of 13 algorithms for predicting incident long-wave radiation under clear skies, ten cloud correction algorithms, and four algorithms for all-sky conditions using data from 21 sites across North America and China. Data from five research sites were combined with publicly available data from nine sites in the AmeriFlux network for initial evaluation and optimization of cloud cover estimates; seven additional AmeriFlux sites were used as an independent test of the algorithms. Clear-sky algorithms that excelled in predicting Lclr were the Dilley, Prata, and Angström algorithms. Root mean square deviation (RMSD) between predicted and measured 30-minute or hourly Lclr averaged approximately 23 W m-2 for these three algorithms across all sites, while RMSD of daily estimates was as low as 14 W m-2. Cloud-correction algorithms of Kimball, Unsworth, and Crawford described the data best when combined with the Dilley clear-sky algorithm. Average RMSD across all sites for these three cloud corrections was approximately 24 to 25 W m -2 for 30-minute or hourly estimates and approximately 15 to 16 W m-2 for daily estimates. The Kimball and Unsworth cloud corrections require an estimate of cloud cover, while the Crawford algorithm corrects for cloud cover directly from measured solar radiation. Optimum limits in the clearness index, defined as the ratio of observed solar radiation to theoretical terrestrial solar radiation, for complete cloud cover and clear skies were suggested for the Kimball and Unsworth algorithms. Application of the optimized algorithms to seven independent sites yielded similar results. On the basis of the results, the recommended algorithms can be applied with reasonable accuracy for a wide range of climates, elevations, and latitudes. © 2009 by American Geophysical Union

How urban form influence urban heat island : perspectives and strategies from different scales and disciplines

Urban heat island (UHI) has been a widespread problem attracting particular attentions for years, and recent studies have shown that urban form is crucial to the formation of UHI at all scales. The relationship between urban form and UHI from the perspective of different scales and disciplines has been investigated with a systematic review. Firstly, we discuss the influence of urban form on UHI at three kinds of scales. 1) at regional scale, the UHI effect of specific urban agglomeration is studied. It’s indicated that UHI is more likely to be affected by the urban geometric characteristics and the level of urban development and construction at this scale. 2) at urban scale, natural surface like greenspace and water body could significantly alleviate UHI effect, while building density and population density show the opposite impact. Sky view factor has complex mechanism on influencing the UHI that may lead to the contradictory results. 3) at block scale, urban form is referred to the layout and structure of buildings, streets and open spaces. The key issue of UHI mitigation in this scale is to promote air circulation and heat dissipation. Secondly, we analyse the academic background of scholars. scholars from geography discipline focus on the external factors that lead to the formation of UHI like urbanization. Researchers from urban environment pay more attention to the urban ecosystem and the way to alleviate the UHI effect. Scholars from planning and design discipline focus more on studying the impact of streets and buildings on the UHI effect from the perspective of practical construction. Finally, we point out the existing problems of the research and put forward improving strategies for the future study, which is the interaction effect between the element of urban form should be more explored and the importance of urban green space need to be highlighted

The effect of a home-based strength training program on type 2 diabetes risk in obese Latino boys

This paper is designed to determine the effects of a home-based strength training (HBST) intervention on insulin sensitivity (SI), compensatory acute insulin response and β-cell function, body composition measures, and maximum strength in obese Latino boys. A total of 26 obese Latino males aged between 14 and 18 years were randomized to either a twice-weekly (n=15) or a control group (C; n=15) for 16 weeks. HBST for 16 weeks, composed of two 1-h sessions per week. Outcome measures were assessed pre-and post-intervention/control condition and included SI, acute insulin response to glucose (AIR) and disposition index (DI), fasting glucose, 2-h glucose, body composition using waist-hip circumferences, body mass index (BMI), dual energy X-ray absorptiometry (DEXA) scan, blood pressure, and strength by 1-repetition maximum. A repeated measures GLM was used to assess differences in changes in outcome measures, between the C and the HBST groups. There were no significant overall intervention effects on any of the outcome variables (p<0.05). These results suggest that an HBST does not improve SI, maximal strength or decrease adiposity in obese Latino boys

FISH karyotype of 85 common wheat cultivars/lines displayed by ND-FISH using oligonucleotide probes

Fluorescence in situ hybridization (FISH) can reveal minor structural differences of chromosomes. The karyotype of common wheat (Triticum aestivum L.) based on FISH pattern is seldom reported. In this study, non-denaturing FISH (ND-FISH) using Oligo-pSc119.2-1, Oligo-pTa535-1 and (AAG)6 as probes was used to investigate the chromosomal structure of 85 common wheat including 83 wheat-rye 1RS.1BL translocation cultivars/lines, a wheatrye 1RS.1AL translocation cultivar Amigo and Chinese Spring (CS). Two, three, two, three, six, three and four structural types respectively for 1A, 2A, 3A, 4A, 5A, 6A and 7A chromosomes were observed. Two, eight, two, two, four and six types of chromosome for 2B, 3B, 4B, 5B, 6B and 7B were respectively detected. The structure of 1B chromosomes in Amigo and CS is different. Five, two, two and two types of chromosomal structure respectively for 1D, 2D, 3D and 5D were distinguished. Polymorphisms of 1RS.1BL, 4D, 6D and 7D chromosomes were not detected. Chromosomes 1AI, 2AI, 3AI, 4AI, 5AIII, 6AI, 7AIII, 2BI, 3BV, 4BI, 5BII, 6BIII, 7BI, 1DIV, 2DI, 3DI and 5DII appeared in these 85 wheat cultivars/lines at high frequency. Each of the 85 wheat cultivars/lines has a unique karyotype. Amigo is a complex translocation cultivar. The FISH karyotype of wheat chromosomes built in this study provide a reference for the future analyzing wheat genetic stocks and help to learn structural variations of wheat chromosomes. In addition, the results in this study indicate that oligonucleotide probes and ND-FISH technology can be used to identify individual wheat cultivar

Miniaturized optical fiber Bragg grating sensor interrogator based on echelle diffractive gratings

An Optical fiber Bragg grating sensor interrogation device based on monolithically integrated echelle diffractive grating and detector arrays on an InP chip is designed and prototyped. The device weighs less than 60 g and measures smaller than 45 mm × 30 mm × 15 mm, and it is specifically designed for potential integration into aerospace applications. This study discusses this device's operation principle and presents some initial experimental results reflecting its performance

Microbial Translocation Is Associated with Increased Monocyte Activation and Dementia in AIDS Patients

Elevated plasma lipopolysaccharide (LPS), an indicator of microbial translocation from the gut, is a likely cause of systemic immune activation in chronic HIV infection. LPS induces monocyte activation and trafficking into brain, which are key mechanisms in the pathogenesis of HIV-associated dementia (HAD). To determine whether high LPS levels are associated with increased monocyte activation and HAD, we obtained peripheral blood samples from AIDS patients and examined plasma LPS by Limulus amebocyte lysate (LAL) assay, peripheral blood monocytes by FACS, and soluble markers of monocyte activation by ELISA. Purified monocytes were isolated by FACS sorting, and HIV DNA and RNA levels were quantified by real time PCR. Circulating monocytes expressed high levels of the activation markers CD69 and HLA-DR, and harbored low levels of HIV compared to CD4+ T-cells. High plasma LPS levels were associated with increased plasma sCD14 and LPS-binding protein (LBP) levels, and low endotoxin core antibody levels. LPS levels were higher in HAD patients compared to control groups, and were associated with HAD independently of plasma viral load and CD4 counts. LPS levels were higher in AIDS patients using intravenous heroin and/or ethanol, or with Hepatitis C virus (HCV) co-infection, compared to control groups. These results suggest a role for elevated LPS levels in driving monocyte activation in AIDS, thereby contributing to the pathogenesis of HAD, and provide evidence that cofactors linked to substance abuse and HCV co-infection influence these processes

Turning a "useless" ligand into a "useful" ligand:a magneto-structural study of an unusual family of Cu(II) wheels derived from functionalised phenolic oximes

While the phenolic oximes (R-saoH(2)) are well known for producing monometallic complexes of the type [MII(R-saoH)(2)] with Cu-II ions in near quantitative yield, their derivatisation opens the door to much more varied and interesting coordination chemistry. Here we show that combining the complimentary diethanolamine and phenolic oxime moieties into one organic framework (H4L1 and H4L2) allows for the preparation and isolation of an unusual family of [Cu-II](n) wheels, including saddle-shaped, single-stranded [Cu-8(II)] wheels of general formula [Cu-8(HL1)(4)(X)(4)] n[Y] (when n = 0, X = Cl-, NO3-, AcO-, N-3(-); when n = 2+X = (OAc)(2)/(2,2'-bpy)(2) and Y = [BF4](2)) and [Cu-8(HL2)(4)(X)(4)](X = Cl-, Br-), a rectangular [Cu-6(HL1)(4)] wheel, and a heterometallic [Cu4Na2(HL1)2(H2L1)(2)] hexagon. Magnetic studies show very strong antiferromagnetic exchange between neighbouring metal ions, leading to diamagnetic ground states in all cases. DFT studies reveal that the magnitude of the exchange constants are correlated to the Cu-N-O-Cu dihedral angles, which in turn are correlated to the planarity/puckering of the [Cu-II](n) rings