Infrared radiative performance of urban trees: spatial distribution and interspecific comparison among ten species in the UK by in-situ spectroscopy

Understanding the ways in which tree species interact with solar radiation has previously focused on transmission and reflection of sunlight, typically by examining individual leaves. Here we used a tree crown spectroscopy measurement method to conduct in-situ tests on the radiative performance of ten commonly planted tree species in the UK. Tree crown transflectance (comprehensive effect of transmission and reflection) was examined to determine i), how radiative performance of individual trees varies spatially within a species, and ii), how infrared radiative performance differs between tree species. Our results show that tree crown transflectance depends on the combination of tree crown morphology, local foliage distribution (leaf density, gaps in crown foliage contour, concave or convex crown shapes), solar altitude and leaf size. Spatially, the strongest tree crown transflection was found primarily towards sky on the sunlit side of trees rather than towards the zenith, meaning that infrared transflection towards surrounding buildings and pedestrians is substantial. For all ten species, the tree crown transflectance in the frontal sunlit area was linearly correlated with solar altitude on sunny days. Hence, a solar altitude of 45° was chosen as the benchmark condition for comparing interspecific differences. Interspecific comparison indicated that interspecific differences in the infrared radiative performance levels were strongly dependent on leaf size when no obvious gaps or concave shapes were present within the tree crowns. Our findings provide insights for understanding radiative interactions between urban trees and surrounding built environment, as well as for tree species selection in urban heat stress mitigation

A quick measurement method for determining the incidence angle modifier of flat plate solar collectors using spectroradiometer

In real engineering of solar thermal applications, it needs considerable effort to determine the incidence angle modifier (IAM) of flat plate solar collectors, according to the test standards (BS EN ISO 9806, 2017; ASHRAE 93-2010, 2014). And the available method in the test standards is usually inapplicable to measure thermal performance of installed solar collectors with dust deposition effect in service. A quick measurement method is therefore presented to identify the IAM of flat plate solar collectors with less effort using a spectroradiometer. The quick method developed was validated with optical tests of a solar panel under the conditions of different incidence angles. It is inferred that the method not only helps to determine the IAM of flat plate solar collectors quickly without needing to run the collectors by energy power input, but also provides a pathway for assessing dust deposition effect on the thermal performance of installed flat plate solar collectors in service, as well as for determining the optical property attenuation of solar collectors in the long-term running

Concept and methodology of characterising infrared radiative performance of urban trees using tree crown spectroscopy

Urban trees play an important role in cooling urban microclimates and regulating outdoor thermal comfort. To better understand their contribution to these processes, it is crucial to elucidate urban trees’ radiative thermal performance, especially in the infrared (IR) region (approximately 50% of solar radiation). Yet, owing to significant conceptual and methodological challenges, studies on the radiative performance of trees have mainly focused on individual leaves rather than crown-level characteristics. Here we applied a novel conceptual and methodological framework to characterise the crown-level IR radiative performance of 10 lime trees (Tilia cordata), a common urban tree in the UK and Europe. Our results show that reflected and transmitted solar energy from leaves is dominated (>70%) by IR radiation. At the leaf level, transmission and reflection spectra are similar between trees (differences typically 40% in IR region) were found between trees. These variations were largely due to crown structural differences (leaf number, density, angles), rather than leaf solar interaction character (leaf-level transmittance or reflectance, leaf colour). Crown transflectance measured from the four cardinal directions was significantly different in the IR region (maximum differences circa 30%), and changed substantially with solar time. Hence, a tree’s surroundings received very different, and time dependent, levels of solar IR radiation. These findings have significant implications for species selection and control of environmental stress factors in urban microclimates

catena-Poly[(diaqua­strontium)-bis­{μ-5-[4-(1H-imidazol-1-yl)phen­yl]tetra­zolido}]

In the title complex polymer, [Sr(C10H7N6)2(H2O)2]n, the SrII atom lies on an inversion centre and is coordinated by four N atoms from two bidentate bridging trans-related 5-[4-(1H-imidazol-1-yl)phen­yl]tetra­zolide ligands [Sr—N = 2.387 (4) Å for the tetrazolide moiety and Sr—N = 2.273 (5) Å for the imidazole moiety], and by two O atoms from water mol­ecules [Sr—O = 2.464 (4) Å], giving a distorted octa­hedral coordination. Pairs of ligand bridges link the complex units, forming chains which extend along [111] and are inter-associated through Owater—H⋯N hydrogen bonds, giving a two-dimensional network structure parallel to (001). Weak π–π stacking inter­actions between the benzene and imidazole rings are also present [minimum ring centroid separation = 3.691 (4) Å]

Systematic identification and characterization of chicken (Gallus gallus) ncRNAs

Recent studies have demonstrated that non-coding RNAs (ncRNAs) play important roles during development and evolution. Chicken, the first genome-sequenced non-mammalian amniote, possesses unique features for developmental and evolutionary studies. However, apart from microRNAs, information on chicken ncRNAs has mainly been obtained from computational predictions without experimental validation. In the present study, we performed a systematic identification of intermediate size ncRNAs (50–500 nt) by ncRNA library construction and identified 125 chicken ncRNAs. Importantly, through the bioinformatics and expression analysis, we found the chicken ncRNAs has several novel features: (i) comparative genomic analysis against 18 sequenced vertebrate genomes revealed that the majority of the newly identified ncRNA candidates is not conserved and most are potentially bird/chicken specific, suggesting that ncRNAs play roles in lineage/species specification during evolution. (ii) The expression pattern analysis of intronic snoRNAs and their host genes suggested the coordinated expression between snoRNAs and their host genes. (iii) Several spatio-temporal specific expression patterns suggest involvement of ncRNAs in tissue development. Together, these findings provide new clues for future functional study of ncRNAs during development and evolution

Rapid assessment of knowledge, attitudes, practices, and risk perception related to the prevention and control of Ebola virus disease in three communities of Sierra Leone

Questionnaire on Ebola knowledge, attitudes, practices, and risk perception in three communities of Sierra Leone, 2015. (DOCX 34 kb