Arbuscular mycorrhizal trees influence the latitudinal beta-diversity gradient of tree communities in forests worldwide

Arbuscular mycorrhizal (AM) and ectomycorrhizal (EcM) associations are critical for host-tree performance. However, how mycorrhizal associations correlate with the latitudinal tree beta-diversity remains untested. Using a global dataset of 45 forest plots representing 2,804,270 trees across 3840 species, we test how AM and EcM trees contribute to total beta-diversity and its components (turnover and nestedness) of all trees. We find AM rather than EcM trees predominantly contribute to decreasing total beta-diversity and turnover and increasing nestedness with increasing latitude, probably because wide distributions of EcM trees do not generate strong compositional differences among localities. Environmental variables, especially temperature and precipitation, are strongly correlated with beta-diversity patterns for both AM trees and all trees rather than EcM trees. Results support our hypotheses that latitudinal beta-diversity patterns and environmental effects on these patterns are highly dependent on mycorrhizal types. Our findings highlight the importance of AM-dominated forests for conserving global forest biodiversity.

Effects of energy-restricted feeding during rearing on sexual maturation and reproductive performance of Rugao layer breeders

The aim of this study was to assess the effects of energy-restricted feeding during rearing on the sexual maturation and reproductive performance of Rugao layer breeders. A total of 2,400 8-wk-old Rugao layer breeders were randomly assigned to one of 5 groups (480 pullets per group) with eight replicates and were fed one of 5 diets that were nutritionally similar with the exception of apparent metabolizable energy corrected for nitrogen (AME_n) content (2,850, 2,750, 2,650, 2,550, and 2,450 kcal AME_n/kg) from 8 to 18 wks of age. The daily amount of feed was restricted to the absolute quantity of the diet consumed by laying hens fed 2,850 kcal AME_n per kg diet ad libitum (control). From 18 to 52 wks of age, all hens were fed basal diets ad libitum. The body weight of layer breeders at 18 wks of age decreased linearly with increasing energy restriction (P < 0.001), but caught up within 3 wks of ad libitum feeding (P = 0.290). The coefficient of variation of the body weight of the hens at 18, 21, and 24 wks of age decreased linearly (P = 0.010, 0.025, and 0.041, respectively) with increasing energy restriction during rearing. Energy-restricted feeding delayed sexual organ development at 18, 20, and 22 wks of age, including the number of large yellow follicles, oviduct length, oviduct length index, oviduct index, and ovary stroma index (P < 0.05), and delayed sexual maturity, including the age at laying the first egg and the age at 5% and 50% egg production (P = 0.042, 0.004, and 0.029, respectively). Consequently, egg number from 5% to 50% egg production decreased linearly as the degree of energy restriction increased (P = 0.001) and egg production of hens in the energy-restricted feeding groups was lower than that of hens in the ad libitum feeding group (6.36, 6.43, 6.4, and 4.61% vs. 14.29%; P < 0.05) from 18 to 20 wks of age. Furthermore, egg weight increased linearly as energy restriction increased (P < 0.001) and laying hens in the most severe energy-restricted feeding group had more setting eggs (normal eggs weighing >40 g) than hens in the ad libitum feeding and lighter energy-restricted feeding groups (149.57 vs. 144.34, 142.66, 143.63, and 141.78; P < 0.05). No significant differences were observed in fertility, hatchability of fertile eggs, and hatchability of setting eggs (P = 0.381, 0.790, and 0.605, respectively). In conclusion, moderate energy restriction (85.97%, 2,450 vs. 2,850 kcal AME_n/kg) from 8 to 18 wks of age increased egg weight as well as the production of setting eggs in native layer breeders throughout the laying period, without adverse effects on productive performance from 18 to 52 wks of age, or fertility and hatchability at 52 wks of age.

Interactions between all pairs of neighboring trees in 16 forests worldwide reveal details of unique ecological processes in each forest, and provide windows into their evolutionary histories

When Darwin visited the Galapagos archipelago, he observed that, in spite of the islands' physical similarity, members of species that had dispersed to them recently were beginning to diverge from each other. He postulated that these divergences must have resulted primarily from interactions with sets of other species that had also diverged across these otherwise similar islands. By extrapolation, if Darwin is correct, such complex interactions must be driving species divergences across all ecosystems. However, many current general ecological theories that predict observed distributions of species in ecosystems do not take the details of between-species interactions into account. Here we quantify, in sixteen forest diversity plots (FDPs) worldwide, highly significant negative density-dependent (NDD) components of both conspecific and heterospecific between-tree interactions that affect the trees' distributions, growth, recruitment, and mortality. These interactions decline smoothly in significance with increasing physical distance between trees. They also tend to decline in significance with increasing phylogenetic distance between the trees, but each FDP exhibits its own unique pattern of exceptions to this overall decline. Unique patterns of between-species interactions in ecosystems, of the general type that Darwin postulated, are likely to have contributed to the exceptions. We test the power of our null-model method by using a deliberately modified data set, and show that the method easily identifies the modifications. We examine how some of the exceptions, at the Wind River (USA) FDP, reveal new details of a known allelopathic effect of one of the Wind River gymnosperm species. Finally, we explore how similar analyses can be used to investigate details of many types of interactions in these complex ecosystems, and can provide clues to the evolution of these interactions.

Spatial patterns and ecological drivers of soil nematode β-diversity in natural grasslands vary among vegetation types and trophic position

Understanding biogeographic patterns of community assemblages is a core objective in ecology, but for soil communities these patterns are poorly understood. To understand the spatial patterns and underlying mechanisms of β-diversity in soil communities, we investigated the β-diversity of soil nematode communities along a 3,200-km transect across semi-arid and arid grasslands. Spatial turnover and nested-resultant are the two fundamental components of β-diversity, which have been attributed to various processes of community assembly. We calculated the spatial turnover and nested-resultant components of soil nematode β-diversity based on the β-partitioning framework. Distance matrices for the dissimilarity of soil nematode communities were computed using the 'Sørensen' method. We fitted negative exponential models to compare the distance decay patterns in nematode community similarity with geographic distance and plant community distance in three vegetation types (desert, desert steppe and typical steppe) and along the whole transect. Variation partitioning was used to distinguish the contribution of geographic distance and environmental variables to β-diversity and the partitioned components. Geographic distance and environmental filtering jointly drove the β-diversity patterns of nematode community, but environmental filtering explained more of the variation in β-diversity in the desert and typical steppe, whereas geographic distance was important in the desert steppe. Nematode community assembly was explained more by the spatial turnover component than by the nested-resultant component. For nematode feeding groups, the β-diversity in different vegetation types increased with geographic distance and plant community distance, but the nested-resultant component of bacterial feeders in the desert ecosystem decreased with geographic distance and plant community distance. Our findings show that spatial variation in soil nematode communities is regulated by environmental processes at the vegetation type scale, while spatial processes mainly work on the regional scale, and emphasize that the spatial patterns and drivers of nematode β-diversity differ among trophic levels. Our study provides insight into the ecological processes that maintain soil biodiversity and biogeographic patterns of soil community assemblage at large spatial scales.

Context-dependency of tree species diversity, trait composition and stand structural attributes regulate temperate forest multifunctionality

High species diversity is generally thought to be a requirement for sustaining forest multifunctionality. However, the degree to which the relationship between species-, structural-, and trait-diversity of forests and multifunctionality depend on the context (such as stand age or abiotic conditions) is not well studied. Here, we hypothesized that context-dependency of tree species diversity, functional trait composition and stand structural attributes promote temperate forest multifunctionality including above- and below-ground multiple and single functions. To do so, we used repeated forest inventory data, from temperate mixed forests of northeast China, to quantify two above-ground (i.e. coarse woody productivity and wild edible plant biomass), five below-ground (i.e. soil organic carbon, total soil nitrogen, potassium, phosphorus and sulfur) functions, tree species diversity, individual tree size variation (CV_DBH) and functional trait composition of specific leaf area (CWM_SLA) as well as stand age and abiotic conditions. We found that tree species diversity increased forest multifunctionality and most of the single functions. Below-ground single and multifunctionality were better explained by tree species diversity. In contrast, above-ground single and multifunctionality were better explained by CV_DBH. However, CWM_SLA was also an additional important driver for maintaining above- and below-ground forest multifunctionality through opposing plant functional strategies. Stand age markedly reduced forest multifunctionality, tree species diversity and CWM_SLA but substantially increased CV_DBH. Below-ground forest multifunctionality and tree species diversity decreased while above-ground forest multifunctionality increased on steep slopes. These results highlight that context-dependency of forest diversity attributes might regulate forest multifunctionality but may not have a consistent effect on above-ground and below-ground forest multifunctionality due to the fact that those functions were driven by varied functional strategies of different plant species. We argue that maximizing forest complexity could act as a viable strategy to maximizing forest multifunctionality, while also promoting biodiversity conservation to mitigate climate change effects.

Do Short-Range Correlations Cause the Nuclear EMC Effect in the Deuteron?

The relative contributions to the valence nuclear European Muon Collaboration (EMC) effect in the deuteron arising from nucleon off-shell effects and Fermi motion are examined in models which include nuclear binding and off-shell effects. Contrary to expectations, the effect of Fermi motion overwhelms the off-shell effects for nucleons in short-range correlations (SRCs), calling into question the hypothesized causal connection between SRCs and the EMC effect.

[Effect and mechanism of astaxanthin on acute kidney injury in rats with full-thickness burns]

Objective: To explore the effect and mechanism of astaxanthin on acute kidney injury in rats with full-thickness burns. Methods: Forty-eight male Sprague Dawley rats of 8 to 10 weeks were divided into sham injury group, simple burn group, burn+ vehicle group, burn+ low-dose astaxanthin group, burn+ medium-dose astaxanthin group, and burn+ high-dose astaxanthin group according to the random number table, with 8 rats in each group. The back skin of rats in sham injury group were immersed in warm water of 20 ℃ for 15 s to simulate burn injury, and the back skin of rats in the other 5 groups were immersed in boiled water of 100 ℃ for 15 s to inflict full-thickness burn of 30% total body surface area. Fluid resuscitation was performed in rats in the 5 groups except of sham injury group immediately and 6 h after injury. At 30 min after injury, the rats in sham injury group and simple burn group were injected with 1 mL/kg normal saline via tail vein, rats in burn+ vehicle group were injected with 1 mL/kg astaxanthin solvent via tail vein, and rats in burn+ low-dose astaxanthin group, burn+ medium-dose astaxanthin group, and burn+ high-dose astaxanthin group were respectively injected with 5, 10, 20 mg/kg astaxanthin solution of 5, 10, 20 mg/mL via tail vein. The renal tissue was collected at post injury hour (PIH) 48, and hematoxylin eosin staining was used for histopathological observation and renal tubular injury score. At PIH 48, the venous blood was collected for detecting serum creatinine level through blood biochemical analyzer, and blood urea nitrogen (BUN) level was detected by enzyme-linked immunosorbent assay. The renal tissue was collected to detect the mRNA expressions of myeloperoxidase (MPO), interleukin-1β (IL-1β), and IL-6 by real-time fluorescent quantitative reverse transcription polymerase chain reaction method, and the protein expressions of Toll like receptor 4 (TLR4), phosphorylated nuclear factor kappa B (p-NF-кB) p65, and heme oxygenase 1 (HO-1) were detected by Western blotting. Besides, the expression of HO-1 in renal tissue was detected by immunofluorescence method. Data were statistically analyzed with Kruskal-Wallis H test, Dunn-Sidák correction, one-way analysis of variance, and Bonferroni method. Results: (1) At PIH 48, there were no inflammatory cell infiltrating and degeneration or necrosis of cells in renal tissue of rats in sham injury group, and the structure of renal tubules was intact. The renal tubules of burn rats in each group showed injury manifestation of separation between epithelial cell and basement membrane, and vacuole cells and lysate protein aggregation. The injury degree of renal tissue of rats in burn+ high-dose astaxanthin group was obviously decreased compared with that in simple burn group. (2) At PIH 48, compared with that of sham injury group, the renal tubular damage scores of rats in simple burn group, burn+ vehicle group, burn+ low-dose astaxanthin group, and burn+ medium-dose astaxanthin group were significantly increased (P<0.05 or P<0.01). Compared with those of simple burn group and burn+ vehicle group, the renal tubular damage scores of rats in burn+ medium-dose astaxanthin group and burn+ high-dose astaxanthin group were significantly decreased (P<0.05 or P<0.01). Compared with that of burn+ low-dose astaxanthin group, the renal tubular damage score of rats in burn+ high-dose astaxanthin group was significantly decreased (P<0.01). (3) At PIH 48, the level of serum creatinine of rats in sham injury group was (2.42±0.06) mg/L, which was significantly lower than (6.11±0.11), (6.48±0.08), (5.79±0.09), (4.03±0.12) mg/L of simple burn group, burn+ vehicle group, burn+ low-dose astaxanthin group, and burn+ medium-dose astaxanthin group (P<0.05 or P<0.01). The level of BUN of rats was (21.9±1.3) mmol/L in sham injury group, significantly lower than (32.1±7.4) mmol/L of simple burn group and (30.2±4.8) mmol/L of burn+ vehicle group (P<0.05 or P<0.01). At PIH 48, compared with those of simple burn group and burn+ vehicle group, the levels of serum creatinine and BUN of (16.0±2.9) mmol/L in burn+ medium-dose astaxanthin group, serum creatinine of (3.02±0.08) mg/L and BUN of (14.5±2.9) mmol/L in burn+ high-dose astaxanthin group, and serum creatinine of (22.8±5.5) mmol/L of rats in burn+ low-dose astaxanthin group were significantly decreased (P<0.05 or P<0.01). At PIH 48, compared with those of burn+ low-dose astaxanthin group, the levels of serum creatinine and BUN of burn+ high-dose astaxanthin group and serum creatinine of burn+ medium-dose group were obviously decreased (P<0.05 or P< 0.01). (4) At PIH 48, compared with those of sham injury group, the mRNA expressions of MPO, IL-1β, and IL-6 in renal tissue of rats in simple burn group, burn+ vehicle group, burn+ low-dose astaxanthin group, and burn+ medium dose astaxanthin group, and the mRNA expressions of IL-1β and IL-6 in renal tissue of rats in burn+ high-dose astaxanthin group were obviously increased (P<0.01). Compared with those of simple burn group and burn+ vehicle group, the mRNA expressions of MPO, IL-1β, and IL-6 in renal tissue of rats were significantly decreased in burn+ low-dose astaxanthin group, burn+ medium-dose astaxanthin group, and burn+ high-dose astaxanthin group (P<0.01). Compared with those of burn+ low-dose astaxanthin group, the mRNA expressions of MPO, IL-1β, and IL-6 in renal tissue of rats were significantly decreased in burn+ medium-dose astaxanthin group and burn+ high-dose astaxanthin group (P<0.01). The mRNA expressions of MPO, IL-1β, and IL-6 in renal tissue of rats in burn+ high-dose astaxanthin group were significantly decreased compared with those of burn+ medium-dose astaxanthin group (P<0.01). (5) At PIH 48 h, compared with those of sham injury group, the protein expressions of TLR4 and p-NF-кB p65 in renal tissue of rats in simple burn group, burn+ vehicle group, burn+ low-dose astaxanthin group, and burn+ high-dose astaxanthin group were obviously increased (P<0.01). Compared with those of simple burn group, the protein expressions of TLR4 and p-NF-кB p65 in renal tissue of rats in burn+ low-dose astaxanthin group, burn+ medium dose astaxanthin group, and burn+ high-dose astaxanthin group were significantly decreased (P<0.01). (6) The results of Western blotting combined with immunofluorescence method showed that compared with that of sham injury group, the protein expression of HO-1 in renal tissue of rats in burn+ vehicle group, burn+ low-dose astaxanthin group, burn+ medium-dose astaxanthin group, and burn+ high-dose astaxanthin group were significantly increased at PIH 48 (P<0.01), and the protein expression of HO-1 in renal tissue of rats in burn+ medium-dose astaxanthin group and burn+ high-dose astaxanthin group was significantly increased compared with that of simple burn group (P<0.01). Conclusions: Astaxanthin can attenuate the structural damage and functional decline of renal tissue and regulate the release of injury-related inflammatory factors, thus to protect the rats from acute kidney injury after burn. The HO-1/TLR4/NF-кB signaling pathway is the main regulatory mechanism of astaxanthin to achieve anti-inflammation-based renoprotection.

Genome-wide association studies for mottled eggs in chickens using a high-density single-nucleotide polymorphism array

Mottled eggs in layer chickens are gaining increasing attention because of the economic impact on the egg industry caused by the reduced sale value of commodity eggs. However, the genetic architecture underlying mottled eggs is not well understood. The genetic architecture underlying the mottled egg trait was investigated using genome-wide association studies (GWAS) by high-density arrays, using a total of 407 pink eggs and 799 blue eggs from an F₂ resource population generated by crossing Dongxiang Blue-shelled and White Leghorn chickens. The mottled egg score in blue eggs was found to be higher than that in pink eggs. The single-nucleotide polymorphism heritability of mottled egg at laying day and storage for 7 days was 0.18 and 0.20, respectively. Bivariate GWAS provided 29 significant loci, mainly located on GGA2, GGA3, GGA8, GGA10, GGA15, GGA17, and GGA23, affecting mottled egg on laying day. Candidate genes RIMS2, SLC25A32, RIMBP2, VPS13B, and RGS3 were obtained for mottled eggshell by bivariate GWAS and gene annotation. Our findings provide new insights into the genetic architecture of mottled egg in hens, and demonstrate that a genomic selection method would be profitable for breeding out the mottled egg trait.

Foundation species across a latitudinal gradient in China

Foundation species structure forest communities and ecosystems but are difficult to identify without long-term observations or experiments. We used statistical criteria--outliers from size-frequency distributions and scale-dependent negative effects on alpha diversity and positive effects on beta diversity--to identify candidate foundation woody plant species in 12 large forest-dynamics plots spanning 26 degrees of latitude in China. We used these data (1) to identify candidate foundation species in Chinese forests, (2) to test the hypothesis--based on observations of a midlatitude peak in functional trait diversity and high local species richness but few numerically dominant species in tropical forests--that foundation woody plant species are more frequent in temperate than tropical or boreal forests, and (3) to compare these results with data from the Americas to suggest candidate foundation genera in northern hemisphere forests. Using the most stringent criteria, only two species of Acer, the canopy tree Acer ukurunduense and the shrubby treelet Acer barbinerve, were identified in temperate plots as candidate foundation species. Using more relaxed criteria, we identified four times more candidate foundation species in temperate plots (including species of Acer, Pinus, Juglans, Padus, Tilia, Fraxinus, Prunus, Taxus, Ulmus, and Corlyus) than in (sub)tropical plots (the treelets or shrubs Aporosa yunnanensis, Ficus hispida, Brassaiopsis glomerulata, and Orophea laui). Species diversity of co-occurring woody species was negatively associated with basal area of candidate foundation species more frequently at 5- and 10-m spatial grains (scale) than at a 20-m grain. Conversely, Bray-Curtis dissimilarity was positively associated with basal area of candidate foundation species more frequently at 5-m than at 10- or 20-m grains. Both stringent and relaxed criteria supported the hypothesis that foundation species are more common in mid-latitude temperate forests. Comparisons of candidate foundation species in Chinese and North American forests suggest that Acer be investigated further as a foundation tree genus.

Mycorrhizal type influences plant density dependence and species richness across 15 temperate forests

Recent studies suggest that the mycorrhizal type associated with tree species is an important trait influencing ecological processes such as response to environmental conditions and conspecific negative density dependence (CNDD). However, we lack a general understanding of how tree mycorrhizal type influences CNDD strength and the resulting patterns of species abundance and richness at larger spatial scales. We assessed 305 species across 15 large, stem-mapped, temperate forest dynamics plots in Northeastern China and North America to explore the relationships between tree mycorrhizal type and CNDD, species abundance, and species richness at a regional scale. Tree species associated with arbuscular mycorrhizal (AM) fungi showed a stronger CNDD and a more positive relationship with species abundance than did tree species associated with ectomycorrhizal (ECM) fungi. For each plot, both basal area and stem abundance of AM tree species was lower than that of ECM tree species, suggesting that AM tree species were rarer than ECM tree species. Finally, ECM tree dominance showed a negative effect on plant richness across plots. These results provide evidence that tree mycorrhizal type plays an important role in influencing CNDD and species richness, highlighting this trait as an important factor in structuring plant communities in temperate forests.

No pulsed radio emission during a bursting phase of a Galactic magnetar

Fast radio bursts (FRBs) are millisecond-duration radio transients of unknown physical origin observed at extragalactic distances^1-3. It has long been speculated that magnetars are the engine powering repeating bursts from FRB sources^4-13, but no convincing evidence has been collected so far¹⁴. Recently, the Galactic magnetar SRG 1935+2154 entered an active phase by emitting intense soft γ-ray bursts¹⁵. One FRB-like event with two peaks (FRB 200428) and a luminosity slightly lower than the faintest extragalactic FRBs was detected from the source, in association with a soft γ-ray/hard-X-ray flare^18-21. Here we report an eight-hour targeted radio observational campaign comprising four sessions and assisted by multi-wavelength (optical and hard-X-ray) data. During the third session, 29 soft-γ-ray repeater (SGR) bursts were detected in γ-ray energies. Throughout the observing period, we detected no single dispersed pulsed emission coincident with the arrivals of SGR bursts, but unfortunately we were not observing when the FRB was detected. The non-detection places a fluence upper limit that is eight orders of magnitude lower than the fluence of FRB 200428. Our results suggest that FRB-SGR burst associations are rare. FRBs may be highly relativistic and geometrically beamed, or FRB-like events associated with SGR bursts may have narrow spectra and characteristic frequencies outside the observed band. It is also possible that the physical conditions required to achieve coherent radiation in SGR bursts are difficult to satisfy, and that only under extreme conditions could an FRB be associated with an SGR burst.

[Teicoplanin-induced hypersensitivity syndrome in a diabetic foot patient with malignant ulcer]

A 58-year-old male patient with diabetic foot ulcer was admitted to the Second Affiliated Hospital of Zhejiang University School of Medicine on December 11, 2018. The patient was treated with local debridement, vacuum sealing drainage treatment, and dressing change and discharged after basic wound healing. On January 15, 2019, the patient was hospitalized again due to local infection and rupture of wound surface. He underwent a surgical debridement on the third day after second admission and was given intravenous infusion of 0.4 g teicoplanin twice daily. Histopathological examination after surgery showed keratinizing squamous-cell carcinoma. An extended squamous-cell carcinoma resection plus autologous split-thickness skin grafting and vacuum sealing drainage treatment was carried out on the 10th day after second admission. The patient's whole body turned red after surgery with rash, recurrent fever over 39 ℃, leucopenia, and thrombocytopenia. A multi-disciplinary consultation of physicians attributed these symptoms to teicoplanin-induced hypersensitivity syndrome. After withdrawal of teicoplanin and administration of hormone, the patient's temperature returned to normal, and the leucocyte count and platelet count recovered gradually. The patient was cured and discharged on the 49th day after second admission. The case presented reminds us of need to strictly follow the indications of teicoplanin prior to medication, be resolute to the administration and withdrawal, and be alert to adverse drug reactions when above-mentioned abnormalities occur, meanwhile, infection and rheumatic diseases are excluded.

Efficacy evaluation of selenium-enriched yeast in laying hens: effects on performance, egg quality, organ development, and selenium deposition

The aim of this study was to compare the dynamic changes of egg selenium (Se) deposition and deposition efficiency and to evaluate the efficacy of selenium-enriched yeast (SY) in laying hens over the 84 d feeding period after SY supplementation. A total of one thousand one hundred fifty-two 30-wk-old, Hy-Line Brown hens were randomly assigned to 1 of 6 groups (192 laying hens per group) with 6 replicates of 32 birds each, fed a basal diet (without Se supplementation), basal diet with 0.3 mg/kg of Se from sodium selenite (SS) or basal diets with 0.1, 0.2, 0.3, or 0.4 mg/kg of Se from SY, respectively. The results showed that the Se concentrations in the eggs and breasts from hens fed a SY-supplemented diet were significantly higher than those from hens fed a SS-supplemented diet or a basal diet (P < 0.001). There was a positive linear and quadratic correlation between Se concentrations in the eggs from hens fed a SY-supplemented diet and dietary Se supplementation on days 28, 56, and 84 (r² = 0.931, 0.932, 0.976, P < 0.001; r² = 0.946, 0.935, 0.976, P < 0.001), respectively. The Se deposition efficiency in whole eggs from hens fed a basal or SY-supplemented diet weresignificantly higher than those in eggs from hens fed a SS-supplemented diet on days 28, 56, and 84 (P < 0.001), respectively. In addition, there was a positive linear and quadratic correlation between Se concentrations in the eggs from hens fed SY-supplemented diet (r² = 0.655, 0.779, 0.874, 0.781, P < 0.001; r² = 0.666, 0.863, 0.944, 0.781, P < 0.001) or SS-supplemented diet (r² = 0.363, P = 0.002; r² = 0.440, P = 0.002) and number of feeding days. In conclusion, the organic Se from SY has higher bioavailability and deposition efficiency of Se in whole eggs as compared with inorganic Se from SS. The Se concentrations and Se deposition efficiency in the eggs increased from hens fed a SS- or SY-supplemented diet but decreased from hens fed a basal diet with the extension of the experimental duration. The results indicate that the dietary Se supplementation from SY should be limited to a maximum of 0.1 mg Se/kg complete feed when the eggs and meat produced from hens fed a SY-supplemented diet are used as food for humans directly, whereas up to 0.4 mg/kg organic Se from SY can be used to supplement the diets for laying hens when the products are used as raw materials for producing Se-enriched food.

Erratum: Avalanches triggered by Kelvin-Helmholtz instability in a cylindrical plasma device [Phys. Rev. E 100, 033212 (2019)]

This corrects the article DOI: 10.1103/PhysRevE.100.033212.

Integrating the underlying structure of stochasticity into community ecology

Stochasticity is a core component of ecology, as it underlies key processes that structure and create variability in nature. Despite its fundamental importance in ecological systems, the concept is often treated as synonymous with unpredictability in community ecology, and studies tend to focus on single forms of stochasticity rather than taking a more holistic view. This has led to multiple narratives for how stochasticity mediates community dynamics. Here, we present a framework that describes how different forms of stochasticity (notably demographic and environmental stochasticity) combine to provide underlying and predictable structure in diverse communities. This framework builds on the deep ecological understanding of stochastic processes acting at individual and population levels and in modules of a few interacting species. We support our framework with a mathematical model that we use to synthesize key literature, demonstrating that stochasticity is more than simple uncertainty. Rather, stochasticity has profound and predictable effects on community dynamics that are critical for understanding how diversity is maintained. We propose next steps that ecologists might use to explore the role of stochasticity for structuring communities in theoretical and empirical systems, and thereby enhance our understanding of community dynamics.

Temporal stability of aboveground biomass is governed by species asynchrony in temperate forests

Understanding the effects of plant species diversity and trait composition on aboveground biomass is a central focus of ecology and has important implications for biodiversity conservation. However, the simultaneous direct and indirect effects of soil nutrients, species asynchrony, functional trait diversity, and trait composition for explaining the community temporal stability of aboveground biomass remain underrepresented in natural forests. Here, we hypothesized that species asynchrony relative to soil nutrients, functional trait diversity, and trait composition plays a central role in stabilizing the community temporal stability of natural forests. We tested this hypothesis using a structural equation model based on 10-year continuous monitoring data (i.e., three-time repeated forest inventories) in both second-growth and old-growth temperate forests in northeast China. Our results showed that the community temporal stability of aboveground biomass was driven by a strong direct positive effect of species asynchrony in both second-growth and old-growth temperate forests, whereas functional trait diversity and composition (i.e. community-weighted mean of leaf nitrogen content) were of additional importance in an old-growth forest only. Functional trait diversity decreased community-weighted mean of leaf nitrogen content in an old-growth forest, whereas this relationship was non-significant in a second-growth forest. Soil nutrients had non-significant effects on the community temporal stability of both second-growth and old-growth forests. Species asynchrony was the direct determinant of the community temporal stability of aboveground biomass in temperate forests. The direct effect of species asynchrony increased with forest succession, implying that temporal niche differentiation and facilitation increase over time. This study suggests that managing forests with mixtures of both early and late successional species or shade intolerant and tolerant species, not only species diversity, is important for maintaining forest stability in a changing environment. We argue that the species asynchrony effect is crucial to understand the underlying ecological mechanisms for a diversity-biomass relationship in natural forests.

Temporal population variability in local forest communities has mixed effects on tree species richness across a latitudinal gradient

Among the local processes that determine species diversity in ecological communities, fluctuation-dependent mechanisms that are mediated by temporal variability in the abundances of species populations have received significant attention. Higher temporal variability in the abundances of species populations can increase the strength of temporal niche partitioning but can also increase the risk of species extinctions, such that the net effect on species coexistence is not clear. We quantified this temporal population variability for tree species in 21 large forest plots and found much greater variability for higher latitude plots with fewer tree species. A fitted mechanistic model showed that among the forest plots, the net effect of temporal population variability on tree species coexistence was usually negative, but sometimes positive or negligible. Therefore, our results suggest that temporal variability in the abundances of species populations has no clear negative or positive contribution to the latitudinal gradient in tree species richness.

[Treatment and nursing of one patient with burns on perineal region and complicated by secondary multiple organ injuries by exposing to paraquat fluid]

On March 18, 2016, one 53 years old man with burns on perineal region and complicated by secondary multiple organ injuries by exposing to paraquat fluid was admitted to our department. Comprehensive treatment measures including protective mechanical ventilation, intensive care, vacuum sealing drainage, anti-infection, and organ protection were conducted sequentially. Through 33 days of comprehensive treatment and nursing, the patient's condition substantially improved and he left hospital. This case presents that paraquat fluid absorption through skin and mucosa can also lead to severe systemic poisoning, and multiple organ protection is the key to improve the prognosis of this patient.

Avalanches triggered by Kelvin-Helmholtz instability in a cylindrical plasma device

A profile-evolving simulation of the Controlled Shear Decorrelation Experiment (CSDX) linear device is performed with our newly developed code. The simulation result shows an excellent agreement with the experimental observations of profiles and fluctuations of plasma density and electric potential in the B=1000 G standard discharges, suggesting the mechanism of their evolutions. According to our simulation, an avalanche of plasma density, featuring a rapid destruction of particle profile, is triggered every time the dominant instability transits from near adiabatic collisional drift wave to non-adiabatic Kelvin-Helmholtz instability. The avalanches always start at the point where the local vorticity is the maximum among the whole device. A critical vorticity is found for any avalanche to happen. The avalanches always lead to intermittent particle and heat convective structures outside the main plasma column, and these structures are ejected out as avaloids when zonal flow intensity at birth time is weak.

[One case of severe subcutaneous soft tissue infection caused by nonstandard insulin injection]

On January 1st 2018, a male 44 years old diabetic patient with subcutaneous soft tissue infection in right thigh was admitted to our hospital. The patient repeatedly used the same needle to inject insulin subcutaneously in the unsterilized right thigh, and his blood glucose was badly controlled in the long term. Severe subcutaneous soft tissue infection of the right thigh occurred after his fatigue, accompanied with ketoacidosis. Then he received conservative treatment in the local hospital for one month, but the infection persisted. After being transferred to our hospital, we highly suspected the diagnosis of necrotizing fasciitis according to previous test indicators and local B-ultrasound results, but suggestion of aggressive surgery was refused. So we treated him with conservative therapies using sensitive antibiotics and supportive remedies. The patient was basically healed after treatment of 1 month and he was recovered well during the follow-up 2 months after discharged from our hospital. This case emphasizes the importance of standard injection of insulin and early diagnosis of severe subcutaneous soft tissue infection.

Tree mycorrhizal associations mediate soil fertility effects on forest community structure in a temperate forest

Soil fertility influences plant community structure, yet few studies have focused on how this influence is affected by the type of mycorrhizal association formed by tree species within local communities. We examined the relationship of aboveground biomass (AGB) and diversity of adult trees with soil fertility (nitrogen, phosphorus, organic matter, etc.) in the context of different spatial distributions of arbuscular mycorrhizal (AM) and ectomycorrhizal (EM) trees in a temperate forest in Northeast China. Diversity showed a positive trend along the soil fertility gradient driven mostly by a positive relationship between AM tree abundance and soil fertility. By contrast, the AGB showed a negative trend along the soil fertility gradient driven mostly by a negative relationship between EM tree AGB and soil fertility. Furthermore, the opposite trend in the AGB and tree species diversity along the soil fertility gradient led to an overall negative diversity-biomass relationship at the 50-m scale but not the 20-m scale. These results suggest that tree mycorrhizal associations play a critical role in driving forest community structure along soil fertility gradients and highlight the importance of tree mycorrhizal associations in influencing how the diversity-ecosystem function (e.g. biomass) relationships change with soil fertility.

[ABCA4 mutations and phenotype of different hereditary retinopathies in 3 pedigrees]

Objective: To analyze the relationship between genotype and phenotype of different types of hereditary retinopahty caused by ABCA4 gene. Method: Three (3) pedigrees that carried mutations on ABCA4 gene as determined through the second generation sequencing technology were selected from the patients diagnosed with hereditary retinal disease in Ningxia Eye Hospital between Januaryand September 2016. The clinical features of patients and other family members of them were collected and analyzed with complete ophthalmic examinations including visual acuity, best corrected visual acuity, fundus examination, macular OCT, fundus fluorescein angiography and electroretinogram (ERG). The relationship between genotype and phenotype was analyzed. Results: All the 3 pedigrees were autosomal recessive families. Four mutations on ABCA4 gene were detected, the CRD pedigree and the RP pedigress carried a homozygous frameshift mutation respectively. The Stargardt pedigree carried two heterozygous mutations. The onset age of the patients were less than 10 years. The best corrected visual acuity was lower than 0.1 and the macular OCT indicated different levels of macular area atrophy, and the visual electrophysiological changes varied from completely normal to significantly reduced visual stem cell function in different cases. Conclusions: The patients with hereditary retinal disease that carried ABCA4 gene mutations were featured with characteristics of early onset age, rapid progress and severe visual impairment. The second generation sequencing technique has the advantages of rapidness and high efficiency in the diagnosis of hereditary retinal disease. (Chin J Ophthalmol, 2018, 54:775-781).

Multiple abiotic and biotic pathways shape biomass demographic processes in temperate forests

Forests play a key role in regulating the global carbon cycle, and yet the abiotic and biotic conditions that drive the demographic processes that underpin forest carbon dynamics remain poorly understood in natural ecosystems. To address this knowledge gap, we used repeat forest inventory data from 92,285 trees across four large permanent plots (4–25 ha in size) in temperate mixed forests in northeast China to ask the following questions: (1) How do soil conditions and stand age drive biomass demographic processes? (2) How do vegetation quality (i.e., functional trait diversity and composition) and quantity (i.e., initial biomass stocks) influence biomass demographic processes independently from soil conditions and stand age? (3) What is the relative contribution of growth, recruitment, and mortality to net biomass change? Using structural equation modeling, we showed that all three demographic processes were jointly constrained by multiple abiotic and biotic factors and that mortality was the strongest determinant on net biomass change over time. Growth and mortality, as well as functional trait diversity and the community‐weighted mean of specific leaf area (CWM_SLA), declined with stand age. By contrast, high soil phosphorous concentrations were associated with greater functional diversity and faster dynamics (i.e., high growth and mortality rates), but associated with lower CWM_SLA and initial biomass stock. More functionally diverse communities also had higher recruitment rates, but did not exhibit faster growth and mortality. Instead, initial biomass stocks and CWM_SLA were stronger predictors of biomass growth and mortality, respectively. By integrating the full spectrum of abiotic and biotic drivers of forest biomass dynamics, our study provides critical system‐level insights needed to predict the possible consequences of regional changes in forest diversity, composition, structure and function in the context of global change.

[Summary of advances in the research of wound therapy]

Wound healing is a complex and sequential biological process involving various cells and factors under body's regulation. Appropriate interventions play positive roles in promoting effective wound healing and improving healing quality. In the clinical practice, there are many new instruments, dressings, and drugs developed for wound care, including antibacterial dressings, wet dressings, precise debridement, negative pressure wound therapy, cytokines/growth factors, and dermal substitutes, which provide revolutionary means for wound treatment. This article summarizes the effective or mature methods in wound care, providing theoretical and practical basis for choosing appropriate treatment methods in different stages of wound.