Sporidesmium and morphologically similar dematiaceous, hyphomycetous genera are characterised by holoblastic phragmoconidia produced on proliferating or non-proliferating conidiophores. They include ...a number of asexual (anamorphic) genera taxonomically segregated from
Sporidesmium sensu lato and are similar in having schizolytic conidial secession. The taxonomy of these ubiquitous asexual fungi and their affinities with known
Ascomycetes are, however, still obscure. This study incorporates a phylogenetic investigation, based on the LSU nu-rDNA and RNA polymerase II second largest subunit (RPB2) gene sequence, to assess the possible familial placement of
Ellisembia,
Linkosia,
Repetophragma,
Sporidesmiella,
Sporidesmium and
Stanjehughesia, and justify whether anamorphic characters are proper phylogenetic indicators. Phylogenies provide conclusive evidence to suggest that
Sporidesmium is not monophyletic and species are phylogenetically distributed in two major ascomycete classes,
Dothideomycetes and
Sordariomycetes. Morphologies currently used in their classification have undergone convergent evolution and are not phylogenetically reliable. The possible teleomorphic affinities of these anamorphic genera are discussed in light of morphology and molecular data. As these anamorphs, in most cases, are the sole known morph of the holomorph, it is proposed that in the absence of or failure to detect their teleomorphic phase, the anamorph names should be used for the holomorph.
Atmospheric vapor pressure deficit (VPD) is a critical variable in determining plant photosynthesis. Synthesis of four global climate datasets reveals a sharp increase of VPD after the late 1990s. In ...response, the vegetation greening trend indicated by a satellite-derived vegetation index (GIMMS3g), which was evident before the late 1990s, was subsequently stalled or reversed. Terrestrial gross primary production derived from two satellite-based models (revised EC-LUE and MODIS) exhibits persistent and widespread decreases after the late 1990s due to increased VPD, which offset the positive CO
fertilization effect. Six Earth system models have consistently projected continuous increases of VPD throughout the current century. Our results highlight that the impacts of VPD on vegetation growth should be adequately considered to assess ecosystem responses to future climate conditions.
Complement is a central effector system within the immune system and is implicated in a range of inflammatory disorders. CD59 is a key regulator of complement membrane attack complex (MAC) assembly. ...The atherogenic role of terminal complement has long been suspected but is still unclear. Here, we demonstrate that among mice deficient in apolipoprotein (Apo)E, the additional loss of murine CD59 (mCd59ab(-/-)/ApoE(-/-)) accelerated advanced atherosclerosis featuring occlusive coronary atherosclerosis, vulnerable plaque, and premature death and that these effect could be attenuated by overexpression of human CD59 in the endothelium. Complement inhibition using a neutralizing anti-mouse C5 antibody attenuated atherosclerosis in mCd59ab(-/-)/ApoE(-/-) mice. Furthermore, MAC mediated endothelial damage and promoted foam cell formation. These combined results highlight the atherogenic role of MAC and the atheroprotective role of CD59 and suggest that inhibition of MAC formation may provide a therapeutic approach for the treatment of atherosclerosis.
Our limited understanding of the impacts of drought on tropical forests significantly impedes our ability in accurately predicting the impacts of climate change on this biome. Here, we investigated ...the impact of drought on the dynamics of forest canopies with different heights using time‐series records of remotely sensed Ku‐band vegetation optical depth (Ku‐VOD), a proxy of top‐canopy foliar mass and water content, and separated the signal of Ku‐VOD changes into drought‐induced reductions and subsequent non‐drought gains. Both drought‐induced reductions and non‐drought increases in Ku‐VOD varied significantly with canopy height. Taller tropical forests experienced greater relative Ku‐VOD reductions during drought and larger non‐drought increases than shorter forests, but the net effect of drought was more negative in the taller forests. Meta‐analysis of in situ hydraulic traits supports the hypothesis that taller tropical forests are more vulnerable to drought stress due to smaller xylem‐transport safety margins. Additionally, Ku‐VOD of taller forests showed larger reductions due to increased atmospheric dryness, as assessed by vapor pressure deficit, and showed larger gains in response to enhanced water supply than shorter forests. Including the height‐dependent variation of hydraulic transport in ecosystem models will improve the simulated response of tropical forests to drought.
Taller tropical forests experienced greater relative canopy reductions during drought and larger non‐drought increases than shorter forests, but the net effect of drought was more negative in the taller forests. Meta‐analysis of in situ hydraulic traits supports the hypothesis that taller tropical forests are more vulnerable to drought stress due to smaller xylem‐transport safety margins. The hydraulic failure and carbon starvation hypotheses are two main non‐mutually exclusive theories to explain drought‐induced dynamics of tropical forests because of significant carbon–hydraulic interactions.
Amazonian evergreen forests show distinct canopy phenology and photosynthetic seasonality but the climatic triggers are not well understood. This imposes a challenge for modeling leaf phenology and ...photosynthesis seasonality in land surface models (LSMs) across Amazonian evergreen forest biome. On continental scale, we tested two climatic triggers suggested by site observations, vapor pressure deficit (VPD), and short‐wave incoming radiation (SW) for defining leaf shedding and incorporated VPD‐ and SW‐triggered new canopy phenology modules in the ORCHIDEE LSM (hereafter VPD‐AP and SW‐AP versions). Our results show that both VPD and SW are plausible precursors of large scale litterfall seasonality across the basin by comparing against in situ data from 14 sites. Specially, both VPD‐AP and SW‐AP correctly capture the increases in litterfall during the early dry season, followed by a flush of new leaves with increasing photosynthetic rates during the later dry season. The VPD‐AP version performs better than the SW‐AP version in capturing a dry‐season increase of photosynthesis across the wet Amazonia areas where mean annual precipitation exceeds 2,000 mm yr−1, consistent with previous satellite data analysis. Both VPD‐AP and SW‐AP model versions perform well in northern, central and southern Amazon regions where the SW seasonality is unimodal, but miss the seasonality of satellite GPP proxies in the eastern region off the coast of Guyana shield where SW seasonality is bimodal. Our findings imply that atmospheric dryness and sunlight availability likely explain the seasonality of leaf shedding and leaf flush processes, respectively, and consequently control canopy photosynthesis in Amazonian evergreen forests.
Key Points
The new canopy phenology module captures the large‐scale spatial and seasonal patterns of Amazonian forest photosynthesis
Vapor pressure deficits and sunlight explain seasonality of Amazonian forest phenology and photosynthesis
This study for the first time integrates site‐level process knowledge to match diagnostic evidence at large scale across Amazonian forests
In order to increase the power density of the power factor correction converter, a novel integrated structure for both the electromagnetic interference (EMI) filter and the boost inductor is proposed ...with the flexible multilayer foil integration technique, which can reduce the volume of these passive components. Also, the performance of the proposed integrated structure is investigated based on the distributed electromagnetic component model. Furthermore, the design procedure for the integrated structure is detailed. Finally, a prototype of the integrated structure for both the EMI filter and the boost inductor has been built and the experiments demonstrate the validity of the integrated structure.
Poly(styrene-
co-acrylonitrile)/expanded graphite composite sheets with very low in-plane (8.5
×
10
−3 Ω
cm) and through-thickness (1.2
×
10
−2 Ω
cm) electrical resistivities have been prepared. The ...expanded graphite was made by oxidation of natural graphite flakes, followed by thermal expansion at 600 °C. Microscopic results disclosed that the expanded graphite has a legume-like structure, and each “legume” has a honeycomb sub-structure with many diamond-shaped pores. After soaking the expanded graphite with styrene and acrylonitrile monomers, the polymer/expanded graphite composite granules were obtained by in situ polymerization of the monomers inside the pores at 80 °C. The functional groups and microstructures of the oxidized graphite, expanded graphite and composites in the forms of particles or sheets were carefully characterized using various techniques, including X-ray powder diffraction, thermogravimetry, optical and electron microscopy. It was found that the honeycomb sub-structure survived after hot-pressing, resulting in a graphite network penetrating through the entire composite body, which produces a composite with excellent electrical conductivity.
Over the past 2 to 3 decades, Chinese forests are estimated to act as a large carbon sink, yet the magnitude and spatial patterns of this sink differ considerably among studies. Using 3 microwave (L- ...and X-band vegetation optical depth VOD) and 3 optical (normalized difference vegetation index, leaf area index, and tree cover) remote-sensing vegetation products, this study compared the estimated live woody aboveground biomass carbon (AGC) dynamics over China between 2013 and 2019. Our results showed that tree cover has the highest spatial consistency with 3 published AGC maps (mean correlation value R = 0.84), followed by L-VOD (R = 0.83), which outperform the other VODs. An AGC estimation model was proposed to combine all indices to estimate the annual AGC dynamics in China during 2013 to 2019. The performance of the AGC estimation model was good (root mean square error = 0.05 Pg C and R2 = 0.90 with a mean relative uncertainty of 9.8% at pixel scale 0.25°). Results of the AGC estimation model showed that carbon uptake by the forests in China was about +0.17 Pg C year−1 from 2013 to 2019. At the regional level, provinces in southwest China including Guizhou (+22.35 Tg C year−1), Sichuan (+14.49 Tg C year−1), and Hunan (+11.42 Tg C year−1) provinces had the highest carbon sink rates during 2013 to 2019. Most of the carbon-sink regions have been afforested recently, implying that afforestation and ecological engineering projects have been effective means for carbon sequestration in these regions.
A hybrid deposition technique, i.e., electrostatic spray coating (ESC) followed by chemical vapor infiltration (CVI), was used to synthesize cubic boron nitride and titanium nitride (cBN-TiN) hard ...composite coatings. The as-prepared coatings have a surface texture similar to that of lotus leaf. The "valleys" embossed inside the biomimetic surface structure served as nano-/micro-reservoirs of solid lubricant particles of MoS2, sized from nano- to submicron in diameter. MoS2 particles were applied to coating surfaces by a tumbling method. The tumbled solid lubricant particles covered all surface structures, leading to a smoother coating surface (or reduced average surface roughness Rs) Tribological tests were carried out for the coatings both before and after tumbling. Sliding results suggest that the tumbled cBN-TiN coating has a significantly lower coefficient of friction. Effectiveness of the tumbled lubricant layer decreased with increasing testing temperature, as indicated by sliding results at elevated temperatures. Worn coating surfaces and pin scars were characterized using surface profilometer, scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS), focus ion beam, Raman spectroscopy and scanning transmission electron microscopy (STEM). The tumbled MoS2 layer is responsible for friction reduction during dry sliding at different temperature conditions. Sliding induced reorientation of the MoS2 platelets is correlated with the lubrication mechanism. Oxidation caused degradation of MoS2 at higher temperatures, which is consistent with the frictional behavior at elevated temperatures. It is suggested that the biomimetic surface structure is effective for entrapping application-specific solid lubricant particles.
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