Topographic and biotic regulation of aboveground carbon storage in subtropical broad-leaved forests of Taiwan

There is a growing need to understand, and ultimately manage, carbon storage by forest ecosystems. Broad-leaved evergreen forests of Taiwan provide an outstanding opportunity to examine factors that regulate ecosystem carbon storage. We utilized data from three Taiwan Forest Dynamics Plots (FS, LHC, and PTY) in which every tree is identified, measured, tagged and mapped, to examine factors regulating carbon storage as estimated from aboveground biomass. Allometric equations were used to estimate the aboveground biomass of each tree, and a model building procedure was used to examine relationships between plot-level aboveground biomass (AGB; Mg/ha) and a suite of topographic and biotic factors. We found that our study sites have AGB values comparable to some of the most carbon dense forests in the world. Across all three sites, maximum biomass was contained in the taxonomic families Fagaceae, Lauraceae and Theaceae. In the FS site, we identified slope convexity (P = 0.03) and elevation (P < 0.001) as topographic predictors of AGB and found that maximum AGB was found in topographically flat areas. In FS, stem density (P < 0.001) was a significant biotic predictor of AGB and the maxima occurred at intermediate densities. In LHC, we found that convexity (P < 0.001) and slope (P < 0.001) were significantly related to AGB which was maximized along a topographic ridge in the plot. Species richness (P < 0.001) was a significant biotic predictor of AGB in LHC, and the relationship indicated slightly higher AGB at higher levels of species richness. The only significant factor related to AGB in PTY was species richness (P = 0.02). Further work is needed to seek a mechanistic understanding of topographic factors and species richness as drivers of carbon storage in forests.     

Using nonwoven fabrics as culture mediums for extensive green roofs: physical properties and cooling effect

Based on the requirements of extensive green roofs, ploylactide (PLA) fibers, cotton fibers, polyester (PET), and low-melting-point LMPET fibers are combined and produced culture mediums for Crassulaceae plants. The resulting mediums are tested for their physical properties and found to be light weight, which is a required condition for plant growth. These features contribute to efficient construction and maintenance. In addition, the optimal cooling effect of the culture mediums is 9.6 °C, which significantly reduces the amount of heat that invades indoor spaces. The decrease in the amount of heat indoors results in a lower demand for air conditioning so as to achieve energy conservation. The results derived from this study help in the promotion of green roofs, thereby slowing down the urban heat island effect and global warming.     

Neuroprotective effects of resveratrol on cerebral ischemia-induced neuron loss mediated by free radical scavenging and cerebral blood flow elevation

Resveratrol is a natural phytoestrogen and possesses many biological functions such as anti-inflammatory activity and protection against atherosclerosis and myocardial infraction. The present study was carried out to elucidate the neuroprotective effect and possible mechanism of resveratrol on cerebral ischemia-induced hippocampus neuron loss. Sixty adult male rats underwent general anesthesia (urethane, 1.4 g/kg, i.p.) and were divided into three groups: sham operation, ischemia treatment, and ischemia combined with resveratrol administration (20 mg/kg, i.v.). The carotid artery was bilaterally ligated to induce cerebral ischemia. Microdialysis and high-performance liquid chromatography were used to analyze dihydroxybenzoic acid (DHBA) that reflected the hippocampal hydroxyl radical level. Hippocampal nitric oxide was assayed among different groups. During cerebral ischemia, the hydroxyl radical levels were elevated in rats and animals displayed severe neuronal loss. A single dose of resveratrol significantly increased the nitric oxide level and decreased the hydroxyl radical level. The reduction of cerebral blood flow and neuronal loss were also attenuated by resveratrol treatment. The results demonstrated that a single infusion of resveratrol could elicit neuroprotective effects on cerebral ischemia-induced neuron damage through free radical scavenging and cerebral blood elevation due to NO release.     

Correcting quantum errors with entanglement

We show how entanglement shared between encoder and decoder can simplify the theory of quantum error correction. The entanglement-assisted quantum codes we describe do not require the dual-containing constraint necessary for standard quantum error-correcting codes, thus allowing us to "quantize" all of classical linear coding theory. In particular, efficient modern classical codes that attain the Shannon capacity can be made into entanglement-assisted quantum codes attaining the hashing bound (closely related to the quantum capacity). For systems without large amounts of shared entanglement, these codes can also be used as catalytic codes, in which a small amount of initial entanglement enables quantum communication.     

Antifungal agents from heartwood extract of <Emphasis Type="Italic">Taiwania cryptomerioides</Emphasis> against brown root rot fungus <Emphasis Type="Italic">Phellinus noxius</Emphasis>

Taiwania (Taiwania cryptomerioides Hayata) is a native and plantation species in Taiwan, and its heartwood has demonstrated excellent decay resistance. Brown root rot fungus Phellinus noxius has caused severe damage to more than 100 tree species in Taiwan. The aims of this study were to investigate the antifungal activities of Taiwania heartwood extracts against P. noxius and to identify the antifungal compounds. Antifungal activities were examined using the agar dilution method (a direct contact assay) and the inverted lid method (a vapor contact assay). Active compounds were purified using liquid–liquid partition, open-column chromatography and HPLC. Among four soluble fractions (n-hexane, ethyl acetate, n-butanol and water soluble fractions), results showed that n-hexane soluble fraction (HSF) can significantly inhibit the growth of P. noxius via the agar dilution method. Moreover, active compounds present in HSF were obtained using antifungal assay-guided fractionation. Results showed that ferruginol, T-cadinol, α-cadinol and T-muurolol were found to exhibit excellent antifungal activities against P. noxius, and their IC₅₀ values were 16.9, 25.8, 33.8 and 50.6 μg/mL, respectively. According to the current findings, phytochemicals (ferruginol, T-cadinol, α-cadinol and T-muurolol) of Taiwania heartwood had the potential to be used as environmentally benign antifungal agents against P. noxius in place of synthetic or inorganic fungicides.