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Increasing nutrient supply level and eliminating pollution risk are essential to promote farmland soil use. In the soil-plant nutrition cycle, phosphorus is a limiting nutrient, toxic metals such as Cd and Pb are stress threats. Utilizing microorganisms as a bio-amendment could be a viable approach to enhance the cycling of soil phosphorus nutrients and immobilize Cd and Pb in the soil. This study involved the isolation of Aspergillus flavus AF-LRH1, a phosphate solubilizing fungal strain from soil. The strain exhibited the capacity to solubilize calcium phosphate, attaining a phosphorus concentration of 220.73 mg L−1 in the medium. High performance liquid chromatography analysis showed that AF-LRH1 produced a combination of organic acids (tartaric acid 260.7 mg L−1, fumaric acid 0.8 mg L−1, citric acid 911.9 mg L−1) to dissolve Ca 3 (PO 4) 2 by providing H+ ions. AF-LRH1 also utilizes NH 4 + for the biosynthesis of amino acids and releases protons, which facilitate the dissolution of insoluble Ca 3 (PO 4) 2 and calcium phytate. Through these processes, calcium phosphate is partly converted into hydroxyapatite because of biological solubilization. AF-LRH1 strain showed the capability to recover phosphorus from various types of sludge-based solid residue by increasing the solubility of insoluble phosphate compounds for plant nutrient supply. In addition, the combining addition of AF-LRH1 strain and phosphate-containing amendments (calcium phosphate, sludge ash and biochar) benefited the decontamination of Pb and Cd contaminated soil. This finding confirmed the AF-LRH1 could be a promising environmental-friendly biofertilizer suitable for agricultural applications and bioremediation of heavy metal contaminated soil. [Display omitted] • Aspergillus flavus AF-LRH1 could solubilize inorganic and organic phosphorus. • A possible phosphate solubilization pathway of AF-LRH1 strain was proposed. • Aspergillus flavus AF-LRH1 strain recovered phosphorus from sludge ash and biochar. • Aspergillus flavus AF-LRH1 had the potential to be used as alternate P biofertilizers. • Addition of phosphate solid waste and AF-LRH1 strain favors soil Pb and Pb fixation. [ABSTRACT FROM AUTHOR]

• Anaerobic co-digestion of tannery solid and liquid waste simultaneously. • Tannery wastewater as a nutrient supply. • Low biogas production of 1.9 ± 0.3 ml/g of VSS. • Reduction in TOC of 66 %, showing the high efficiency of waste treatment. • Reduction in the cost of wastewater treatment and solid waste disposal. The possibility of using tannery raw wastewater as substitute for the nutrient supply in the anaerobic co-digestion of two tannery solid waste was investigated with regard to energy efficiency, waste treatment efficiency and economic efficiency. The results showed that the use of tannery wastewater as a source of nutrients for the AD of solid tannery waste proved to be adequate from the point of view that the three residues are being treated simultaneously. There was a biogas production of only 1.9 ± 0.3 mL/VSS. However, the percentage of methane in the biogas reached 33 % at the beginning of the process, proving that there was methanogenic activity and that AD established. The cost analysis showed that there is a great reduction in the cost of wastewater treatment and solid waste disposal of 23 % and 18 %, respectively, in terms of electricity consumption and 11 % and 8 % respectively in terms of thermal consumption. [ABSTRACT FROM AUTHOR]

[Display omitted] • Reduced N affected vine vigor and grape yield of Cabernet Gernischt (CG). • Reduced N enhanced anthocyanins, tannins, and total polyphenols in CG wine. • Reduced N improved a majority of individual anthocyanins in CG wine. • Reduced N application increased stilbenes in CG wine. Nitrogen (N) fertilization is important for grape growth and wine quality. Unreasonable N fertilizer application affects wine growth and has a negative impact on wine quality. Therefore, it is essential to address the mismatch between N application and wine composition. To regulate vine growth and improve grape and wine quality, Cabernet Gernischt (Vitis vinifera L.) grapevines were subjected to lower levels of N, compared to normal N supply treatments, during the grape growing seasons of 2019 and 2020 in the wine region of Yantai, China. The effects of reduced N application from pre-boom to pre-veraison on vine growth, yield and composition of grapes, and dry red wine anthocyanin and non-anthocyanin phenolic compound content were studied. We found that reduced N application significantly decreased dormant shoot fresh mass and yield. However, the effect of N application on fruit ripening depended on the season. Nitrogen-reduction treatment significantly improved wine phenolic parameters, including total phenolics, tannins, and anthocyanins, and enhanced most of the individual anthocyanins and some non-anthocyanin phenolics, especially stilbenes, including piceatannol, trans -resveratrol, and polydatin, regardless of the season. Overall, our findings highlight the importance of reducing N application during the grape growing season in order to modify the wine phenolic profiles. [ABSTRACT FROM AUTHOR]

Post-hydrothermal liquefaction wastewater (PHWW), which contains approximately 80% of original feedstock resources, shows great potential to achieve sustainable development of an environment-enhancing energy system. A combination of anaerobic digestion and algae cultivation was proposed for methane recovery and nutrient supply from PHWW. Granular activated carbon (GAC) and ozone were used to enhance energy recovery from the PHWW. The results indicated that with GAC addition, the maximum methane yield increased by 67.7%–228 mL/g COD removal . In addition, Chlorella vulgaris displayed optimal growth in a 5-fold diluted digestate with a 2.32 g/L maximum biomass content and 180 mg/(L·d) biomass production rate. The total energy yield was 565 kJ/g COD, which was 27.4 times higher than that without GAC. Integration of anaerobic digestion and algae cultivation, particularly with GAC addition during fermentation, is a feasible and advantageous process for energy recovery from PHWW. [ABSTRACT FROM AUTHOR]

Export-production in the Southern Ocean is thought to be tightly correlated with atmospheric CO 2 fluctuations over geological times. Relevant studies are, however, mainly confined to the Atlantic and Pacific sectors of the Southern Ocean and often only cover the last glacial-interglacial cycle. Here, we present a sediment record retrieved off Prydz Bay (East Antarctica) spanning the last ~ 520 kyrs. We show that the distribution pattern of local export production is closely coupled with global climate change on orbital time scales. We propose that the dominant factors controlling local export production include the amount of nutrients supply from the ocean interior and the extent of sea ice cover, thus representing the combined history of deep water exposure/ventilation and the sea ice coverage in the studied area. Sharp increases in the local export production coincide with abrupt increase in atmospheric CO 2 concentrations during deglacial periods, indicating drastic outgassing of the upwelled deep water in the Southern Ocean. Gradually decrease in the export production following interglacial peaks concurs with decrease in deep water exposure/ventilation and increase in sea ice cover, explaining the early decline in atmospheric CO 2 over a glacial-interglacial cycle. [ABSTRACT FROM AUTHOR]

Across the Ordovician–Silurian transition, the first large-scale extinction event in geological history, the Late Ordovician mass extinction (LOME), occurred. The LOME was a double-pulse event, and the two extinction pulses occurred in the late Katian – early Hirnantian (LOME-1) and middle Hirnantian (LOME-2). At present, the comprehensive driving mechanism of the two extinction pulses is still controversial. In this study, two cores (JY87 and JY143) from the middle Yangtze shelf in South China were selected as the research objects. Combined with previous research results, four main stressors, namely, volcanism, ocean redox, climate and nutrient supply, were analyzed. On this basis, the two-pulse driving mechanism of the LOME was comprehensively studied. The comprehensive mechanisms driving the two extinction pulses were different. During the LOME-1, the intensity of volcanism was relatively weak. Volcanic silicate weathering, high nutrients and long-term accumulation of high organic carbon burial flux may have jointly caused cold conditions and led to the expansion of the anoxic sulfide zone and enhancement of sulfidation. The cold conditions had less effect on deep-water benthos, but enhanced euxinia led to their extinction. In contrast, shallow-water benthos were less affected by the enhanced euxinia, but the cold conditions led to their extinction. During the LOME-2, a sudden and brief increase in volcanism that was extremely intense occurred, bringing in abundant nutrients and SO 2 , resulting in more widespread and long-lasting euxinia. This occurrence led to the extinction of benthos that survived during the LOME-1. • Four stressors that may lead to LOME, including volcanism, ocean redox, climate and nutrient supply, are analyzed. • During the LOME-1, the intensity of volcanism was relatively weak. • During the LOME-2, a sudden and brief increase in volcanism that was extremely intense occurred. • Both cooling and relatively widespread euxinia lead to the occurrence of the LOME-1. • More widespread and long-lasting euxinia lead to the occurrence of the LOME-2. [ABSTRACT FROM AUTHOR]

Microplastics have emerged as an important threat to terrestrial ecosystems. To date, little research has been conducted on investigating the effects of microplastics on ecosystem functions and multifunctionality. In this study, we conducted the pot experiments containing five plant communities consisting of Phragmites australis, Cynanchum chinense , Setaria viridis , Glycine soja , Artemisia capillaris , Suaeda glauca , and Limonium sinense and added polyethylene (PE) and polystyrene (PS) microbeads to the soil (contained a mixture of 1.5 kg loam and 3 kg sand) at two concentrations of 0.15 g/kg (lower concentration, hereinafter referred to as PE-L and PS-L) and 0.5 g/kg (higher concentration, hereinafter referred to as PE-H and PS-H) to explore the effects of microplastics on total plant biomass, microbial activity, nutrient supply, and multifunctionality. The results showed that PS-L significantly decreased the total plant biomass (p = 0.034), primarily by inhibiting the growth of the roots. β-glucosaminidase decreased with PS-L, PS-H, and PE-L (p < 0.001) while the phosphatase was noticeably augmented (p < 0.001). The observation suggests that the microplastics diminished the nitrogen requirements and increased the phosphorus requirements of the microbes. The decrease in β-glucosaminidase diminished ammonium content (p < 0.001). Moreover, PS-L, PS-H, and PE-H reduced the soil total nitrogen content (p < 0.001), and only PS-H considerably reduced the soil total phosphorus content (p < 0.001), affecting the ratio of N/P markedly (p = 0.024). Of interest, the impacts of microplastics on total plant biomass, β-glucosaminidase, phosphatase, and ammonium content did not become larger at the higher concentration, and it is observable that microplastics conspicuously depressed the ecosystem multifunctionality, as microplastics depreciated single functions such as total plant biomass, β-glucosaminidase, and nutrient supply. In perspective, measures to counteract this new pollutant and eliminate its impact on ecosystem functions and multifunctionality are necessary. [Display omitted] • Microplastics reduced total plant biomass and soil nutrient supply. • Microplastics affected microbial activity and microbial nutrient requirements. • Microplastics depressed the ecosystem multifunctionality. • Microplastic effects on ecosystem functions were not larger at higher concentration. [ABSTRACT FROM AUTHOR]

• Unbalanced C/N ratio may cause over-growth of lactic acid bacteria (LAB). • Adequate C/N ratio may boost balance and syntrophy between LAB and H 2 -producers. • Resilience to process perturbations is key for high-rate hydrogen production. • Biohythane production: 14.2 kJ g-VS−1, 81 NmL-H 2 g-VS−1 + 543 NmL-CH 4 g-VS−1. Dark fermentation is gaining importance as a bioprocess able to valorize different organic wastes/wastewaters through the co-production of organic acids and biogenic hydrogen (bioH 2). In this study, the process performance and microbial community structure of a mesophilic lab-scale fermenter inoculated with an enriched hydrogenogenic consortium and fed with undiluted tequila vinasse (TV) were evaluated for 28 days equivalent to 112 hydraulic retention times (HRT). The influence of external nutrients supply on process performance was carefully evaluated. The fermenter was operated at 6 h HRT and fed with i) TV without additional nutrients, ii) TV with additional nitrogen (0.3 g/L), and iii) TV supplemented with nitrogen (0.3 g/L) and iron (0.01 g/L) chemical sources. Despite the inherent presence of macro- and micronutrients in TV, the use of raw TV with no additional nutrients resulted in a very low hydrogen production rate of 24 NmL-H 2 L−1h−1. Contrarily, a nitrogen dosing of 1.2 g-NH 4 Cl L−1 led to a sudden increase in the bioH 2 production, reaching productivity and yield values of 283 NmL-H 2 L−1h−1 and 82 NmL-H 2 g −1-volatile solids added, respectively. The further addition of FeSO 4 ·7H 2 O (0.05 g/L) did not improve the TV-to-bioH 2 conversion. Bridging hydrogen production and organic acids with molecular analysis, 16S rRNA gene sequencing, indicated that maintaining a suitable C/N ratio in the fermenter could ensure balance and syntrophy between lactic acid bacteria (e.g., Sporolactobacillus , Lactobacillus) and bioH 2 producers (Clostridium). Further biochemical methane potential tests with the fermentation broth demonstrated that biohythane process (bioH 2 + CH 4) resulted in 5 % higher bioenergy recovery than that derived from the single-stage anaerobic digestion. [ABSTRACT FROM AUTHOR]

Large areas of peatlands have worldwide been drained to facilitate agriculture, which has adverse effects on the environment and the global climate. Agriculture on rewetted peatlands (paludiculture) provides a sustainable alternative to drainage-based agriculture. One form of paludiculture is the cultivation of Sphagnum moss, which can be used as a raw material for horticultural growing media. Under natural conditions, most Sphagnum mosses eligible for paludiculture typically predominate only in nutrient-poor wetland habitats. It is unknown, however, how the prevailing high nutrient levels in rewetted agricultural peatlands interfere with optimal Sphagnum production. We therefore studied the effect of enriched nutrient conditions remaining even after top soil removal and further caused by external supply of nutrient-rich irrigation water and (generally) high inputs of atmospheric nitrogen (N) to habitat biogeochemistry, biomass production and nutrient stoichiometry of introduced Sphagnum palustre and S. papillosum in a rewetted peatland, which was formerly in intensive agricultural use. Airborne N was responsible for the major supply of N. Phosphorus (P) and potassium (K) were mainly supplied by irrigation water. The prevailing high nutrient levels (P and K) are a result of nutrient-rich irrigation water from the surroundings. Peat porewater (10 cm below peatmoss surface) CO 2 concentrations were high, bicarbonate concentrations low, and the pH was around 4.2. Provided that moisture supply is sufficient and dominance of fast-growing, larger graminoids suppressed (in order to avoid outshading of Sphagnum mosses), strikingly very high biomass yields of 6.7 and 6.5 t DW ha −1 yr −1 ( S. palustre and S. papillosum [including S. fallax biomass], respectively) were obtained despite high N supply and biomass N concentrations. Despite high P and K supply and uptake, N:P and N:K ratios in the Sphagnum capitula were still low. Sphagnum mosses achieved high nutrient sequestration rates of 34 kg N, 17 kg K and 4 kg P ha −1 yr −1 from May 2013 to May 2014, which shows that the site acted as an active nutrient sink. Nutrient management still needs further improvement to reduce the competitive advantage of fast growing peatmoss species (cf. S. fallax ) at the expense of slower growing but preferred peatmosses as horticultural substrate ( S. palustre and S. papillosum ) to optimize the quality of biomass yields. In conclusion, Sphagnum farming is well able to thrive under high N input provided that there is a simultaneous high input of P and K from irrigation water, which facilitates high production rates. Due to the lack of suitable, nutrient poor sites, it seems to be useful to remove the topsoil (mainly P removal) prior to start growing Sphagnum mosses. In addition, bicarbonate concentrations have to stay sufficiently low to ensure a low pH, CO 2 supply from the peat soil should be sufficiently high to prevent C limitation, and graminoids should be mown regularly. [ABSTRACT FROM AUTHOR]

Latest Paleocene and early Eocene hyperthermals were geologically brief, profound environmental perturbations caused by massive additions of 13 C-depleted carbon to the ocean-atmosphere system, and therefore provide ancient analogs to assess the impact of modern global warming on the Earth's ecosystem. We document and compare population changes in calcareous nannoplankton, the major primary producers in Paleogene oceans, across three consecutive hyperthermal episodes of differing magnitudes (i.e., the most severe Paleocene/Eocene Thermal Maximum (PETM), the relatively mild Eocene Thermal Maximum 2 (ETM2) and the least severe H2) in the tropical Atlantic. Across all three hyperthermal events, the total abundance and the abundance of the eutrophic and mesotrophic taxa decreased significantly, while oligotrophic taxa increased markedly, suggesting that oligotrophy prevailed in tropical Atlantic surface waters. A nonmetric multidimensional scaling ordination revealed that, during the peak of each hyperthermal, nannoplankton communities featured excursion taxa and assemblages substantially deviated from the pre-event composition. However, during the recovery phase, nannoplankton communities rapidly returned to quasi pre-event compositions for the ETM2 and H2 perturbations, but remained distinct from the pre-event composition for the PETM. This contrast between pre- and post-event compositions of nannoplankton communities may imply that the PETM perturbation exceeded the resilience threshold of the tropical Atlantic surface ecosystem and caused a regime shift, cautioning the possible risk of an abrupt state change in oceanic ecosystem under the present situation, which has a considerably faster and greater perturbation to the C cycle than during the PETM. [ABSTRACT FROM AUTHOR]

Neuronal function requires constant working conditions and a well-balanced supply of ions and metabolites. The metabolic homeostasis in the nervous system crucially depends on the presence of glial cells, which nurture and isolate neuronal cells. Here we review recent findings on how these tasks are performed by glial cells in the genetically amenable model organism Drosophila melanogaster . Despite the small size of its nervous system, which would allow diffusion of metabolites, a surprising division of labor between glial cells and neurons is evident. Glial cells are glycolytically active and transfer lactate and alanine to neurons. Neurons in turn do not require glycolysis but can use the glially provided compounds for their energy homeostasis. Besides feeding neurons, glial cells also insulate neuronal axons in a way similar to Remak fibers in the mammalian nervous system. The molecular mechanisms orchestrating this insulation require neuregulin signaling and resemble the mechanisms controlling glial differentiation in mammals surprisingly well. We hypothesize that metabolic cross talk and insulation of neurons by glial cells emerged early during evolution as two closely interlinked features in the nervous system. This article is part of a Special Issue entitled SI: Myelin Evolution . [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the effects of feeding canola meal (CM) or wheat dried distillers grains with solubles (W-DDGS) as the major source of protein in diets varying in crude protein (CP) content on ruminal fermentation, microbial protein production, omasal nutrient flow, and production performance in lactating dairy cows. Eight lactating dairy cows were used in a replicated 4 x 4 Latin square design with 29-d periods (21 d of dietary adaptation and 8 d of measurements) and a 2 x 2 factorial arrangement of dietary treatments. Four cows in 1 Latin square were ruminally cannulated to allow ruminal and omasal sampling. The treatment factors were (1) source of supplemental protein (CM vs. W-DDGS) and (2) dietary CP content (15 vs. 17%; DM basis). Diets contained 50% forage and 50% concentrate, and were fed twice daily at 0900 and 1600 h as total mixed rations for ad libitum intake. Dry matter intake and milk yield were unaffected by dietary treatments; however, milk yield in cows that were fed CM was numerically greater (+1.1 kg/d) when compared with cows fed W-DDGS. Feeding CM increased milk lactose content compared with feeding W-DDGS. Milk urea nitrogen and ruminal NH3-N concentrations were greater in cows fed the high-CP compared with those fed the low-CP diet. The rumen-degradable protein supply was greater in cows fed the high-CP when compared with those fed the low-CP diet when diets contained CM, whereas rumen-degradable protein supply was lower in cows fed the high-CP when compared with those fed the low-CP diet when diets contained W-DDGS. Total N flow at the omasal canal was not affected by diet; however, omasal flow of NH3-N was greater in cows fed CM when compared with those fed W-DDGS. The rumen-undegradable protein supply was greater in cows fed the low-CP when compared with those fed the high-CP diet when diets contained CM, whereas rumen-undegradable protein supply was lower in cows fed the low-CP when compared with those fed the high-CP diet when diets contained W-DDGS. Omasal flow of fluid-associated bacteria was greater and that of particle-associated bacteria tended to be greater in cows fed CM when compared with those fed W-DDGS; however, omasal flow of total microbial nonammonia N was unaffected by dietary treatment. Omasal flows of threonine and tryptophan were greater, whereas that of histidine and lysine tended to be greater in cows fed CM when compared with those fed W-DDGS. Our results show that when dairy diets are formulated to contain 15 or 17% CP, CM or W-DDGS can be used as the major source of protein and achieve similar levels of milk production. [ABSTRACT FROM AUTHOR]

• The Xiamaling Formation was deposited in an oxidative marine environment. • The difference in total organic carbon and nutrient elements between black shale and green shale is associated with extreme climate change. • Unstable nutrient supply would hinder the evolution of early-life at ∼ 1.4 Ga. The Mesoproterozoic Era (ca.1.6–1.0 Ga) witnessed a long-term evolution stasis of eukaryote, which is usually ascribed to the persistent low atmospheric oxygen levels. However, several oxygenation processes were identified on different continents during the Mesoproterozoic Era, implying that the oxygen levels may not be the only factor influencing the evolution of early-life during the early Mesoproterozoic Era. Here, we report the molybdenum isotopes, redox sensitive elements, nutrient elements and total organic carbon (TOC) content of black and green shales from the ∼ 1.4 Ga Xiamaling Formation in the northern part of the North China Craton (NCC), which has been affected by Milankovitch-style cycle, orbital forcing of extreme change of climate ∼ 1.4 billion years ago. The highest δ98Mo of the green shale reaches 1.56 ± 0.04 ‰ (modern ocean: 2.34 ‰), which may also confirm that it was in an oxygenation state at that time. In contrast, the black shale has lower δ98Mo values (1.02 ± 0.07 ‰) than that of green shale, indicating a less oxidized environment. Moreover, the TOC and nutrient elements (e.g., P, Cu, Ni) contents of the black shale are higher than those of green shale, which results from an increased nutrient input caused by stronger weathering and river runoff during a wet period. We conclude that the marine environment was persistently oxidative during the deposition of the black and green shales, while the TOC contents of the black and green shales are mainly controlled by the concentration of the nutrient elements that are constrained by the climatic conditions. Even though in oxic aquatic environment, the unstable nutrient supply would hinder the early life evolution, our findings imply vice versa. Hence, these results imply that the extreme climate change leading to unsustainable supply of nutrients, may have largely influenced emergence and diversification of animals in the Mesoproterozoic Era. [ABSTRACT FROM AUTHOR]

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Nuclear factor-erythroid 2 p45-related factor 2 (Nrf2) regulates the basal and stress-inducible expression of a battery of genes encoding key components of the glutathione-based and thioredoxin-based antioxidant systems, as well as aldo-keto reductase, glutathione S- transferase, and NAD(P)H:quinone oxidoreductase-1 drug-metabolizing isoenzymes along with multidrug-resistance-associated efflux pumps. It therefore plays a pivotal role in both intrinsic resistance and cellular adaptation to reactive oxygen species (ROS) and xenobiotics. Activation of Nrf2 can, however, serve as a double-edged sword because some of the genes it induces may contribute to chemical carcinogenesis by promoting futile redox cycling of polycyclic aromatic hydrocarbon metabolites or confer resistance to chemotherapeutic drugs by increasing the expression of efflux pumps, suggesting its cytoprotective effects will vary in a context-specific fashion. In addition to cytoprotection, Nrf2 also controls genes involved in intermediary metabolism, positively regulating those involved in NADPH generation, purine biosynthesis, and the β-oxidation of fatty acids, while suppressing those involved in lipogenesis and gluconeogenesis. Nrf2 is subject to regulation at multiple levels. Its ability to orchestrate adaptation to oxidants and electrophiles is due principally to stress-stimulated modification of thiols within one of its repressors, the Kelch-like ECH-associated protein 1 (Keap1), which is present in the cullin-3 RING ubiquitin ligase (CRL) complex CRL Keap1 . Thus modification of Cys residues in Keap1 blocks CRL Keap1 activity, allowing newly translated Nrf2 to accumulate rapidly and induce its target genes. The ability of Keap1 to repress Nrf2 can be attenuated by p62/sequestosome-1 in a mechanistic target of rapamycin complex 1 (mTORC1)-dependent manner, thereby allowing refeeding after fasting to increase Nrf2-target gene expression. In parallel with repression by Keap1, Nrf2 is also repressed by β-transducin repeat-containing protein (β-TrCP), present in the Skp1–cullin-1–F-box protein (SCF) ubiquitin ligase complex SCF β-TrCP . The ability of SCF β-TrCP to suppress Nrf2 activity is itself enhanced by prior phosphorylation of the transcription factor by glycogen synthase kinase-3 (GSK-3) through formation of a DSGIS-containing phosphodegron. However, formation of the phosphodegron in Nrf2 by GSK-3 is inhibited by stimuli that activate protein kinase B (PKB)/Akt. In particular, PKB/Akt activity can be increased by phosphoinositide 3-kinase and mTORC2, thereby providing an explanation of why antioxidant-responsive element-driven genes are induced by growth factors and nutrients. Thus Nrf2 activity is tightly controlled via CRL Keap1 and SCF β-TrCP by oxidative stress and energy-based signals, allowing it to mediate adaptive responses that restore redox homeostasis and modulate intermediary metabolism. Based on the fact that Nrf2 influences multiple biochemical pathways in both positive and negative ways, it is likely its dose–response curve, in terms of susceptibility to certain degenerative disease, is U-shaped. Specifically, too little Nrf2 activity will lead to loss of cytoprotection, diminished antioxidant capacity, and lowered β-oxidation of fatty acids, while conversely also exhibiting heightened sensitivity to ROS-based signaling that involves receptor tyrosine kinases and apoptosis signal-regulating kinase-1. By contrast, too much Nrf2 activity disturbs the homeostatic balance in favor of reduction, and so may have deleterious consequences including overproduction of reduced glutathione and NADPH, the blunting of ROS-based signal transduction, epithelial cell hyperplasia, and failure of certain cell types to differentiate correctly. We discuss the basis of a putative U-shaped Nrf2 dose–response curve in terms of potentially competing processes relevant to different stages of tumorigenesis. [ABSTRACT FROM AUTHOR]

The influence of nutrients on the growth of Ulva prolifera was studied in the SYS by field experiments. The wet weight of U. prolifera gradiently increased from 11.94% to 25.92% in proportion to contents of DIN supply, which indicated DIN content was essentially decisive for the output of U. prolifera blooms. Continuous nutrient supply could promote the growth of U. prolifera , indicated by the increase of growth rate from 10.46% of the batch culture to 42.17% of the in situ culture. The higher P utilized rate in all treatments showed P was the potential limited factor for the growth of U. prolifera . Moreover, it was calculated about 4.1 × 10 5 t organic matter was begot by U. prolifera in the whole Yellow Sea based on the statistical relationship between output of U. prolifera and DIN content. This work could be convenient to evaluate biomass and prepare enough tools to manage U. prolifera . [ABSTRACT FROM AUTHOR]

Nutrients are material basis of eutrophication and algal blooms in the water body. Xiangxi Bay (XXB), the largest tributary bay in the lower reach of the Three Gorges Reservoir (TGR), is subject to such eutrophication and algal blooms. In order to investigate the supply patterns of nutrients in XXB, stable isotopes of hydrogen (δD) and oxygen (δ 18 O), nutrients, and flow velocity were observed from September 2012 to December 2013. A two-compartment linear mixing model based on the tracer principle of δD and δ 18 O was employed to calculate the water and nutrients contributions to XXB from the mainstream of TGR and the upper tributaries of the XXB. The average nutrients concentrations of XXB were estimated and compared to the observed values in the field. The results suggested that there was obvious layered and bidirectional density current in XXB, which had a significant impact on nutrient supply pattern and spatial and temporal distribution of the isotopes and nutrients in XXB. The water contributions of the mainstream of TGR and the upper tributaries for XXB were 84% and 16%, respectively. Moreover, the nitrogen and phosphorus nutrients imported into XXB through the mainstream of TGR were over 80% and 60%, respectively, higher than those of the upper tributaries. The calibration of nutrients concentration in XXB showed that the error between the calculated and the observed was about within 20%, which confirmed further the reliability that the nutrients in XXB come mainly from the mainstream of TGR. The results address the attention that the pollution control should be implemented not only in the tributary watershed, but also the whole upstream region of the TGR for prevention of its tributaries algal blooms. [ABSTRACT FROM AUTHOR]

Highlights: [•] 5-Tolyltriazole biodegradation significantly improved by biomass acclimation. [•] Biodegradation enhancement by non-specific sludge supernatant addition. [•] Nitrogen addition also increased biodegradation rate. [•] Degradation presumably starts by benzene ring cleavage serving as a carbon source. [•] Heterocyclic N-containing ring is assumed not to be cleaved necessitating N-supply. [ABSTRACT FROM AUTHOR]

Abstract: The birth of modern life on Earth can be linked to the adequate supply of nutrients into the oceans. In this paper, we evaluate the relative supply of nutrients into the ocean. These nutrients entered the ocean through myriad passageways, but primarily through accelerated erosion due to uplift. In the ‘second ecosystem’, uplift is associated with plume-generation during the breakup of the Rodinia supercontinent. Although the evidence is somewhat cryptic, it appears that the second ecosystem included the demospongia back into the Cryogenian (~750Ma). During the Ediacaran–Cambrian interval, convergent margin magmatism, arc volcanism and the closure of ocean basins provided a second pulse of nutrient delivery into the marine environment. A major radiation of life forms begins around 580Ma and is represented by the diverse and somewhat enigmatic Ediacaran fauna followed by the Cambrian Explosion of modern phyla during the 540–520Ma interval. Tectonically, the Ediacaran–Cambrian time interval is dominated by the formation of ultra-high pressure (UHP), high pressure (HP) and ultra-high temperature (UHT) orogenic belts during Gondwana orogenesis. Erosion of this extensive mountainous region delivered vast nutrients into the ocean and enhanced the explosiveness of the Cambrian radiation. The timing of final collisional orogeny and construction of the mountain belts in many of the Gondwana-forming orogens, particularly some of those in the central and eastern belts, post-date the first appearance of modern life forms. We therefore postulate that a more effective nutrient supply for the Cambrian radiation was facilitated by plume-driven uplift of TTG crust, subsequent rifting, and subduction-related nutrient systems prior to the assembly of Gondwana. In the outlined scenario, we propose that the birth of the ‘second ecosystem’ on our planet is plume-driven. [Copyright &y& Elsevier]

Parasites with complex life cycles frequently increase their transmission to definitive hosts (where reproduction occurs) by increasing the susceptibility of intermediate hosts to predation by definitive hosts. While recent evidence finds that anthropogenic driven habitat alterations can alter host–parasite relationships, whether such alterations interact with intermediate host manipulation to influence infection prevalence and food web structure remains unknown. We develop a nutrient-limited food web model to investigate how manipulation of intermediate host susceptibility, nutrient supply, and predator diversity determine parasite abundance and infection prevalence in intermediate and definitive hosts. We show that the effects of intermediate host manipulation on parasite abundance and infection prevalence depend on nutrient supply while the coexistence of competing definitive hosts and “dead-ends” (where parasites cannot reproduce) depends primarily on intermediate host susceptibility to predation. Our results suggest that anthropogenic changes in nutrient supply will interact with host–parasite relationships to determine parasite abundance, infection prevalence, and food web structure. [Copyright &y& Elsevier]

A study was conducted to determine the effects of replacing canola meal (CM) as the major protein source with wheat-based dried distillers grains with solubles (W-DDGS) on ruminal fermentation, microbial protein production, omasal nutrient flow and animal performance. Eight lactating dairy cows were fed in a replicated 4 x 4 Latin square design with 28-d periods (20 d of dietary adaptation and 8 d of measurements). Four cows in one Latin square were ruminally cannulated for measurements of ruminal fermentation characteristics and flow of nutrients at the omasal canal. Cows were fed either a standard barley silage-based total mixed ration containing CM as the major protein supplement (0% W-DDGS, control) or diets formulated to contain 10, 15, and 20% W-DDGS (dry matter basis), with W-DDGS replacing primarily CM. Diets were isonitrogenous (18.9% crude protein) and contained 3.0, 3.2, 3.5, and 3.7% ether extract for 0, 10, 15, and 20% W-DDGS, respectively. Diets contained 50% forage and 50% concentrate. Inclusion of W-DDGS linearly increased dry matter intake (29.5, 31.2, 30.2, and 31.9 kg/d for 0, 10, 15, and 20% W-DDGS, respectively). The addition of W-DDGS in place of CM resulted in a 1.2- to 1.8-kg increase in milk yield (42.9, 44.7, 44.1, and 44.5 kg/d for 0, 10, 15, and 20% W-DDGS); however, a quadratic change in feed efficiency (i.e., milk yield/DM intake) occurred as the dietary level of W-DDGS increased. Treatments did not differ for milk fat, protein, and lactose concentrations; however, quadratic changes were observed in milk yields of fat (1.48, 1.56, 1.62, and 1.55 kg/d for 0, 10, 15, and 20% W-DDGS, respectively), protein (1.44, 1.46, 1.49, and 1.42 kg/d) and lactose (1.96, 2.02, 2.09, and 1.93 kg/d). Ruminal fermentation characteristics did not change except that the inclusion of 20% W-DDGS resulted in a decrease and a tendency for a decrease in molar concentrations of isobutyrate and total volatile fatty acids, respectively. Omasal flow of total bacterial nonammonia N (NAN) and bacterial efficiency (g of total bacterial NAN flow/kg of organic matter truly digested in the rumen) were not different among diets; however, feeding W-DDGS resulted in a quadratic increase in nonammonia nonbacterial N flow at the omasal canal (271, 318, 336, and 311 g/d for 0, 10, 15, and 20% W-DDGS, respectively). These data indicate that W-DDGS can substitute for CM as the major protein source in dairy cow diets without negatively affecting ruminal fermentation, microbial protein production, and omasal nutrient flow, and can potentially increase dry matter intake and milk yield. [ABSTRACT FROM AUTHOR]

Species diversity influences the productivity of ecosystems across habitats, and may influence their susceptibility to environmental changes. More diverse communities are often found to be more productive because selection and complementarity effects allow more efficient use of available resources. However, which principles promote coexistence in pelagic model ecosystems is only beginning to be understood as are controls on the diversity–productivity relationship. Here we show that the diversity–productivity relationship of phytoplankton in a global self-assembling ocean ecosystem model depends on the simulated nutrient supply. Increasing productivity with increasing diversity can be found in regions with high nutrient supply. Using a simple idealized model we show that a more diverse community can be more productive if different phytoplankton types utilize complementary niches, here created by preferential zooplankton grazing, thereby increasing resource use. In our model context, total nutrient supply determines a maximum diversity sustained by the ecosystem. Systems with a low nutrient supply cannot sustain high productivity of more diverse communities and produce a neutral or even negative diversity–productivity relationship. Our model results suggest links between diversity, productivity and export production in marine pelagic ecosystems, with the potential for feedbacks of diversity on productivity in response to expected future environmental changes. [Copyright &y& Elsevier]

Abstract: Sufficient nutrient and oxygen transport is a potent modulator of cell proliferation in in vitro tissue-engineered constructs. The lack of oxygen and culture medium can create a potentially lethal environment and limit cellular metabolic activity and growth. Diffusion through scaffold and multi-cellular tissue typically limits transport in vitro, leading to potential hypoxic regions and reduction in the viable tissue thickness. For the in vitro generation of clinically relevant tissue-engineered grafts, current nutrient diffusion limitations should be addressed. Major approaches to overcoming these include culture with bioreactors, scaffolds with artificial microvasculature, oxygen carriers and pre-vascularization of the engineered tissues. This study focuses on the development and utilization of a new perfusion culture system to provide adequate nutrient delivery to cells within large three-dimensional (3D) scaffolds. Perfusion of oxygenated culture medium through porous hollow fiber (HF) integrated within 3D free form fabricated (FFF) scaffolds is proposed. Mouse pre-myoblast (C2C12) cells cultured on scaffolds of poly(ethylene-oxide-terephthalate)–poly(butylene-terephthalate) block copolymer (300PEOT55PBT45) integrated with porous HF membranes of modified poly(ether-sulfone) (mPES, Gambro GmbH) is used as a model system. Various parameters such as fiber transport properties, fiber spacing within a scaffold and medium flow conditions are optimized. The results show that four HF membranes integrated with the scaffold significantly improve the cell density and cell distribution. This study provides a basis for the development of a new HF perfusion culture methodology to overcome the limitations of nutrient diffusion in the culture of large 3D tissue constructs. [Copyright &y& Elsevier]

Abstract: The aim of this experiment was to investigate the effect of Haemonchus contortus infection on rumen function and digestion of Merino sheep from lines divergently selected for genetic resistance to H. contortus. Rumen function and whole-tract digestibility were determined in 29 Merino weaner wethers from the CSIRO Haemonchus selection flock, increased resistance to Haemonchus (IRH), decreased resistance to Haemonchus (DRH) and random bred control (C) selection lines. Wethers were fed a restricted low quality roughage diet (5.9MJ ME/kg DM, 29g MP/kg DM) to maintain weight and were either uninfected (NIL) or infected with H. contortus (INF). Measurements were taken at week 7 of infection, while animals were housed in metabolic crates. Animals were then euthanased to determine abomasal worm counts. IRH had significantly lower worm egg count than DRH and C lines however, adult worm and larval counts, though lower in IRH animals, did not differ significantly. DM and OM digestibility and in sacco degradability of IRH and DRH selection lines were greater than C animals. Rumen function of animals from the IRH line was altered in response to H. contortus infection with an increase in fluid outflow and turnover rate and a decrease in propionic acid concentration. These changes may be a component of a greater host resistance and begin to explain the failure of IRH animals to translate lower worm egg count into greater bodyweight gain. [Copyright &y& Elsevier]

Abstract: The main limitation in engineering in vitro tissues is the lack of a sufficient blood vessel system — the vascularization. In vivo almost all tissues are supplied by these endothelial cell coated tubular networks. Current strategies to create vascularized tissues are discussed in this review. The first strategy is based on the endothelial cells and their ability to form new vessels known as neoangiogenesis. Herein prevascularization techniques are compared to approaches in which biomolecules, such as growth factors, cytokines, peptides and proteins as well as cells are applied to generate new vessels. The second strategy is focused on scaffold-based techniques. Naturally-derived scaffolds, which contain vessels, are distinguished from synthetically manufactured matrices. Advantages and pitfalls of the approaches to create vascularized tissues in vitro are outlined and feasible future strategies are discussed. [Copyright &y& Elsevier]

Abstract: Hindcast experiment with an eddy-permitting ocean ecosystem model was performed in order to investigate the process of nutrient supply into the euphotic zone by vertical and horizontal fluxes with multiple time scales. The model reasonably reproduced the basin-scale spatial pattern of biological production and its seasonal cycles with eddy fields, statistically consistent with those observed in the satellite images. The model results illustrated the nutrient cycle in the euphotic zone with mesoscale eddies, in which the vertical advection with mesoscale spatial variation and convection with relatively large spatial variation supply nutrients into the euphotic zone, and the horizontal advection redistributes them within the euphotic zone, thereby fueling biological production. The vertical advection associated with mean flow supplies a substantial part of nutrients from the aphotic zone, and contributions from time-varied vertical fluxes are limited within the tropical region and regions where strong meandering currents exist. Horizontal advection due to seasonal and eddy fluctuations plays an important role in the redistribution process, in addition to that effected by temporal-mean advection. The relative importance of these fluctuations strongly depends on the horizontal scales of vertical nutrient supply, in contrast to the relatively small effects eddy fields have on heat or fresh-water transport in the global ocean. [Copyright &y& Elsevier]

Abstract: Biotic soil parameters have so far seldom played a role in practical soil assessment and management of grasslands. However, the ongoing reduction of external inputs in agriculture would imply an increasing reliance on ecosystem self-regulating processes. Since soil biota play an important role in these processes and in the provision of ecosystem services, biological soil parameters should be an integral part of soil assessment. The general objective of the current study is to investigate to what extent biotic soil parameters provide additional value in soil quality assessment of grassland on sandy soils. We measured abiotic and biotic soil parameters together with process parameters underlying ecosystem services in 20 permanent production grasslands. Cross-validated stepwise regression was used to identify abiotic and biotic soil parameters that explained the soil ecosystem services soil structure maintenance, water regulation, supply of nutrients, and grassland production, respectively. Process parameters underlying the ecosystem service soil structure maintenance such as bulk density and the percentage of sub-angular blocky elements were mainly influenced by SOM and its qualities. The correlations between penetration resistance at 0–10cm and the percentage of soil crumbs with earthworms suggested a relationship to earthworm activity. Parameters underlying the service of water regulation showed no clear relationship to biotic soil parameters. Water infiltration rate in the field was explained by the penetration resistance at 10–20cm. Process parameters underlying the service of nutrients’ supply such as the potentially mineralizable C and N were mainly determined by soil total N. The potential C and N mineralization were more related to biotic soil parameters, whereby each parameter was the other’s antithesis. The grassland production without N fertilization viz. the nitrogen supply capacity of the soil measured as N yield, was mainly explained by soil organic matter (SOM) and soil moisture, and to a lesser extent by soil total N. One gram of SOM per kg of dry soil corresponded to 3.21kgNyieldha−1, on top of a constant of 15.4kgNha−1. The currently applied calculations in the Dutch grassland fertilization recommendation, underestimated in 85% of the production grasslands, the measured nitrogen supply capacity of the soil by on average 42kgNha−1 (31%). This legitimizes additional research to improve the currently applied recommendations for sandy soils. The response of N yield to N fertilization ranged from 35 to 102%. This wide range emphasizes the importance of a better recommendation base to target N fertilizer. The response of N yield to N fertilization was predicted by the total number of enchytraeids, the underlying mechanism of which needs further investigation on different soil types. This knowledge can be important for the optimal use of fertilizer and its consequences for environmental quality. [Copyright &y& Elsevier]

Using a dual-flow continuous culture fermenter system, this study evaluated the effect of timing of corn silage supplementation on ruminal digestion and nutrient flows following a short and intensive orchardgrass herbage meal. Treatments included 28 g dry matter (DM) of corn silage added either 9 h (9BH; 0700 h) or 1 h (1BH; 1500 h) before adding 42 g DM orchardgrass herbage or no corn silage (control; 70 g DM herbage). Herbage was fed as follows: 66% of the total herbage meal at 1600 h, 22% at 1720 h, and the remaining 12% at 1840 h. Effluent was analyzed for organic matter (OM), crude protein (CP), and neutral detergent fiber (NDF). Purine concentrations in effluent and bacterial isolates were used to estimate the partition of effluent N flow into bacterial and nonbacterial fractions, and to calculate true OM digestibility. Fermenters were sampled for pH, volatile fatty acids (VFA), and NH3-N at 0730, 1100, 1530, 1600, 1720, 1840, and 2000 h on d 10. Data were analyzed as a 3 × 4 Latin square experimental design. True digestibilities for OM (average of 78.5%) and CP (average of 84.6%), and apparent NDF digestibility (average of 82.7%) were not affected by treatment. Mean ruminal pH was lower for 9BH than for 1BH, averaging 5.6 and 6.5, respectively. Molar proportions of acetate were not affected by treatment. Propionate concentration was greater for 9BH than for 1BH, averaging 20.5 and 18.1 mM, respectively. Diurnal patterns of pH, NH3-N, and acetate:propionate ratio were affected by treatment: 9BH had the lowest values for all measurements as the day progressed. The NH3-N concentration and effluent NH3-N flow were higher for 1BH (11.4 mg/100 mL and 0.26 g/d, respectively) than for 9BH (8.8 mg/100 mL and 0.20 g/d, respectively). Effluent NH3-N flow (as a % of total N flow) was the lowest for 9BH. Bacterial efficiency was not affected by treatments, with a mean of 10.5 g of N/kg of OM truly digested. Under the same resource allocation (pasture plus supplement), a simple change in timing of corn silage feeding (9 rather than 1 h before an orchardgrass herbage meal) may alter ruminal fermentation pattern. These changes could increase the glucogenic nutrient supply and improve N utilization by reducing ammonia N losses. [ABSTRACT FROM AUTHOR]

Abstract: Attempting to achieve a balance between the supply of and requirements for the major nutrients implies that demands for major nutrients can be adequately quantified, that the nutritive value of the consumed diet can be described in similar terms and that the diet actually consumed by the grazing sheep can be estimated, or at least predicted, from pasture and animal conditions. Several systems exist for defining the nutrient requirements of sheep and, whilst there are real differences between them, all are sufficiently accurate to allow their use in ration formulation and in grazing animal management. Similarly, nutritive value of feed components can be defined accurately. In grazing sheep, the major difficulty in balancing the supply of consumed nutrients against nutrient requirements is the estimation of diet composition and intake. Computer-based decision support tools are a useful aid to overcoming this problem. It is suggested that since profit derives from animal production per hectare and not per animal, the balancing of nutrient supply and requirements should not be attempted on an individual-animal basis. [ABSTRACT FROM AUTHOR]

Abstract: The healing process for bone fractures is sensitive to mechanical stability and blood supply at the fracture site. Most currently available mechanobiological algorithms of bone healing are based solely on mechanical stimuli, while the explicit analysis of revascularization and its influences on the healing process have not been thoroughly investigated in the literature. In this paper, revascularization was described by two separate processes: angiogenesis and nutrition supply. The mathematical models for angiogenesis and nutrition supply have been proposed and integrated into an existing fuzzy algorithm of fracture healing. The computational algorithm of fracture healing, consisting of stress analysis, analyses of angiogenesis and nutrient supply, and tissue differentiation, has been tested on and compared with animal experimental results published previously. The simulation results showed that, for a small and medium-sized fracture gap, the nutrient supply is sufficient for bone healing, for a large fracture gap, non-union may be induced either by deficient nutrient supply or inadequate mechanical conditions. The comparisons with experimental results demonstrated that the improved computational algorithm is able to simulate a broad spectrum of fracture healing cases and to predict and explain delayed unions and non-union induced by large gap sizes and different mechanical conditions. The new algorithm will allow the simulation of more realistic clinical fracture healing cases with various fracture gaps and geometries and may be helpful to optimise implants and methods for fracture fixation. [Copyright &y& Elsevier]

Abstract: Field trials were conducted in 2006 and 2007 on a sandy soil (Uelzen county, Lower Saxony, Northern Germany) to examine the influence of soil properties as effected by ridge compared to flat cultivation on the growth of sugar beet. Mean daily soil temperature between sowing (mid-March to mid-April) and May (4–6-leaf-stage) was 7.0°C in the ridge and 6.1°C in the flat cultivated soil. In May, total plant dry matter yield (DMY) was 38.7% higher in ridge compared to flat cultivation. Correlation analysis revealed soil temperature as the most important factor effecting early growth. Between May and June (canopy closure), ridge cultivation significantly increased crop growth rate (CGR) like in the period before, but the influence of soil temperature on plant growth diminished and penetration resistance correlated most closely to CGR. In June, DMY increase due to ridge cultivation was 29.7%. During the second half of the growing season, no significant differences in CGR due to cultivation occurred. However, yield was higher in the ridge cultivation treatment until final harvest in October, when white sugar yield (WSY) was increased by 8.4% compared to flat cultivation. It was concluded that the basis of higher final WSY in ridge cultivation was established during early growth until June, primarily caused by warmer soil and growth stimulating soil structure. [Copyright &y& Elsevier]

Abstract: This paper reviews about 190 publications related to the anatomy, morphology and growth of aboveground and belowground parts of common reed (Phragmites australis). In addition to the general description of plant structure, observations on germination, growth dynamics, biomass, effects of habitat conditions such as temperature, salinity, nutrient supply and water depth are evaluated. The impact of animal, fungal and algal attacks, and human intervention (burning and harvesting) on reed growth, and the potential genetic determinacy behind the response of reed to environmental changes are also discussed. [Copyright &y& Elsevier]

• Algae and aquatic vegetation strongly influence E. coli in its natural water habitats. • Algae affect E. coli survival via multiple factors. • Diverse ecological interactions between E. coli and algae are reported. • E. coli - algae interactions need to be considered on different scales. • Microbial water quality management should consider algal and aquatic vegetation effects. Both algae and bacteria are essential inhabitants of surface waters. Their presence is of ecological significance and sometimes of public health concern triggering various control actions. Interactions of microalgae, macroalgae, submerged aquatic vegetation, and bacteria appear to be important phenomena necessitating a deeper understanding by those involved in research and management of microbial water quality. Given the long-standing reliance on Escherichia coli as an indicator of the potential presence of pathogens in natural waters, understanding its biology in aquatic systems is necessary. The major effects of algae and aquatic vegetation on E. coli growth and survival, including changes in the nutrient supply, modification of water properties and constituents, impact on sunlight radiation penetration, survival as related to substrate attachment, algal mediation of secondary habitats, and survival inhibition due to the release of toxic substances and antibiotics, are discussed in this review. An examination of horizontal gene transfer and antibiotic resistance potential, strain-specific interactions, effects on the microbial, microalgae, and grazer community structure, and hydrodynamic controls is given. Outlooks due to existing and expected consequences of climate change and advances in observation technologies via high-resolution satellite imaging, unmanned aerial vehicles (drones), and mathematical modeling are additionally covered. The multiplicity of interactions among bacteria, algae, and aquatic vegetation as well as multifaceted impacts of these interactions, create a wide spectrum of research opportunities and technology developments. [ABSTRACT FROM AUTHOR]

Abstract: In Canada''s eastern boreal forest, the stagnant growth of black spruce (Picea mariana (Mill.) BSP) seedlings is often observed in the presence of ericaceous shrubs such as Kalmia angustifolia L. Many mechanisms, including allelopathic interference, reduced soil N mineralization, soil enzymes inhibition, and direct resource competition have been proposed to explain poor spruce growth in the presence of Kalmia. However, the relative importance of direct competition versus indirect interference remains unclear. Our objective was thus to adequately isolate the “Kalmia effect” from other growth-limiting factors and to determine if removal of Kalmia also resulted in fundamental changes in the biochemical properties of the forest floor. By sampling plots established in 2000, we evaluated how Kalmia eradication and spot fertilization influenced soil nutrient availability, N mineralization rates, microbial basal respiration and biomass, as well as planted black spruce seedling growth, dimensions, and foliar nutrient concentrations 6 years later. We measured higher extractable-P, mineralizable-N, seedling dimensions and growth rates, as well as lower extractable-K, total-K, basal respiration and microbial biomass, in plots without Kalmia than in those where Kalmia had been maintained from 2000 to 2006. Our results thus confirmed that Kalmia eradication over 6 years not only improved the growth and nutrition of black spruce seedlings, but also resulted in fundamental changes in the biochemical properties of the forest floor. We demonstrated that along with direct competition for resources, Kalmia interferes indirectly with black spruce by modifying nutrient cycling and energy fluxes in soil. Higher indices of available C in plots with Kalmia corroborates that Kalmia tannins or rhizodeposition may reduce N mineralization by stimulating microbial immobilization, a relation that however needs to be confirmed with longer term laboratory incubations. Our results indicated that although it had a positive influence on seedling growth, the fertilization effect was confined to the first few years following treatment application, and failed to influence soil processes as did Kalmia eradication. Further monitoring will indicate if the increased litterfall in fertilized plots will eventually initiate a second wave of fertilizer-induced changes to soil processes, as observed in other ecosystems. [Copyright &y& Elsevier]

Production efficiency decreases when diets are not properly balanced for protein. Sensitivity analyses of the protein fractionation schemes used by the National Research Council Nutrient Requirement of Dairy Cattle (NRC) and the Cornell Net Carbohydrate and Protein System (CNCPS) were conducted to assess the influence of the uncertainty in feed inputs and the assumptions underlying the CNCPS scheme on metabolizable protein and amino acid predictions. Monte Carlo techniques were used. Two lactating dairy cow diets with low and high protein content were developed for the analysis. A feed database provided by a commercial laboratory and published sources were used to obtain the distributions and correlations of the input variables. Spreadsheet versions of the models were used. Both models behaved similarly when variation in protein fractionation was taken into account. The maximal impact of variation on metabolizable protein from rumen-undegradable protein (RUP) was 2.5 (CNCPS) and 3.0 (NRC) kg/d of allowable milk for the low protein diet, and 3.5 (CNCPS) and 3.9 (NRC) kg/d of allowable milk for the high protein diet. The RUP flows were sensitive to ruminal degradation rates of the B protein fraction in NRC and of the B2 protein fraction in the CNCPS for protein supplements, energy concentrates, and forages. Absorbed Met and Lys flows were also sensitive to intestinal digestibility of RUP, and the CNCPS model was sensitive to acid detergent insoluble crude protein and its assumption of complete unavailability. Neither the intestinal digestibility of the RUP nor the protein degradation rates are routinely measured. Approaches need to be developed to account for their variability. Research is needed to provide better methods for measuring pool sizes and ruminal digestion rates for protein fractionation systems. [ABSTRACT FROM AUTHOR]

Abstract: According to ocean-color remote sensing data, a low phytoplankton biomass exists in the central parts of the Sulu and Celebes seas, whereas higher concentrations of chlorophyll a are observed in the waters near the Sulu Archipelago, which separates these water bodies. These high-chlorophyll a waters have lower temperatures than those of surrounding waters, indicating vertical mixing of nutrient-rich subsurface water that is attributable to the topographical features of the Sulu Ridge. Differences in photosynthetic parameters, primary productivity and the phytoplankton community structure between the high-chlorophyll area near the Sulu Archipelago and the oligotrophic basin area in the Philippine, Sulu and Celebes seas were investigated in November 2002 during the R.V. Hakuho-Maru KH-02-4 cruise. Entrainment of subsurface water and vertical mixing by intense tidal flow from the Sulu Archipelago to the Celebes Sea created a low-temperature, high-nutrient condition at the southeastern edge of the Sulu Ridge. Chlorophyll a concentrations greater than 2μgl−1 were observed at stations 5–15km offshore at the edge of the Sulu Ridge. This high-chlorophyll tongue in the Celebes Sea showed high primary productivity: it was 1.6–18 times higher than those measured in oligotrophic central basin regions of the Philippine, Sulu, and Celebes seas. Microscopic observation of these high-chlorophyll waters showed the dominance of chain-forming large centric diatoms. Extension of high-chlorophyll waters was not observed at the Sulu Sea side, where the surface water salinity was lower than in the Celebes Sea and consequently prevented intrusion of the Celebes Sea water into the surface layer. Occasional extensions of productive, chlorophyll-rich surface water from the archipelagic zone to the surrounding basin area seems to be an important factor causing spatiotemporal variability in the phytoplankton biomass in the southern Sulu Sea and the western Celebes Sea. [Copyright &y& Elsevier]

Abstract: Several studies on coupled physical–biogeochemical models have shown that major deficiencies in the biogeochemical fields arise from the deficiencies in the physical flow fields. This paper examines the improvement of the physics through data assimilation, and the subsequent impact on the ecosystem response in a coupled model of the North Atlantic. Sea surface temperature and sea surface height data are assimilated with a sequential method based on the SEEK filter adapted to the coupling needs. The model domain covers the Atlantic from 20°S to 70°N at eddy-permitting resolution. The biogeochemical model is a NPZD-DOM model based on the P3ZD formulation. The results of an annual assimilated simulation are compared with an annual free simulation. With assimilation, the representation of the mixed layer depth is significantly improved in mid latitudes, even though the mixed layer depth is generally overestimated compared to the observations. The representation of the mean and variance of the currents is also significantly improved. The nutrient input in the euphotic zone is used to assess the data assimilation impact on the ecosystem. Data assimilation results in a 50% reduction of the input due to vertical mixing in mid-latitudes, and in a four- to six-fold increase of the advective fluxes in mid-latitudes and subtropics. Averaged zonally, the net impact is a threefold increase for the subtropical gyre, and a moderate (20–30%) decrease at mid and high latitudes. Surface chlorophyll concentration increases along the subtropical gyre borders, but little changes are detected at mid and high latitudes. An increase of the primary production appears along the Gulf Stream path, but it represents only 12% on average for mid and high latitudes. In the subtropical gyre centre, primary production is augmented but stays underestimated (20% of observations). These experiments show the benefits of physical data assimilation in coupled physical–biogeochemical applications. [Copyright &y& Elsevier]

Abstract: The Northern Areas of Pakistan form a mountainous, semi-arid region in which subsistence mixed farming is the predominant economic activity for the majority of the population, which numbers around 1 million. Following a period of relative isolation, construction of the Karakoram Highway and the ensuing development activity have been catalysts for rapid infrastructural and social change over the last two decades. In the study reported here, feed resources for the livestock enterprise, which is largely made up of cattle, goats and sheep, were studied in detail over the course of a single winter feeding season. Productive outputs including liveweight change, milk production and reproductive performance were also quantified over a full year. The aim of the study was to provide a quantitative description of the system and to assess the extent to which proximity to a major highway influenced livestock husbandary. Six villages across the region were selected for study as part of a 2×3 factorial design with one village per cell of the study design. Factors consisted of two geographical transects and three agro-ecological zones. Transects were the Karakoram Highway (KKH) transect which enjoyed relatively good transport infrastructure and the Gilgit Ghizer Region (GGR) transect where infrastructure was more limited. Agro-ecological zones were the single, transitional and double cropping zones. One village per transect from each of the three main agro-ecological zones was chosen for study with 6–7 households within each village studied. Results showed that feed resources per household did not vary significantly according to transect or zone but cattle numbers per household were higher in the GGR transect than in the KKH transect indicating a heavier reliance on subsistence livestock production in this transect. Live weight and body condition of livestock in the Northern Areas changed markedly over the annual cycle. Losses of live weight were in the order of 10% over winter while summer gains during the summer season averaged 35% of initial live weight. There were differences between transects, with animals in the KKH gaining less weight in summer but showing higher milk yield (in cattle) and better reproductive performance. The results indicate a typical system of smallholder livestock production with heavy reliance on cereal by-products, a mix of livestock species and a relative scarcity of stored feed resources relative to overall livestock holdings. This study also suggests that proximity to the main highway running through the Northern Areas is associated with a reduced but more feed-efficient livestock production system. [Copyright &y& Elsevier]

Abstract: Nitrogen is a necessary element for much of seaweed physiology, and is the most common limiting nutrient for marine macroalgae. Therefore, the content of nitrogen in algal tissue is often considered a useful indicator of algal productivity. However, the significance of algal nitrogen content in the field is understudied. We used a factorial manipulation of light and herbivory at three sites in order to evaluate how three factors (light, herbivory, wave exposure) affect the nitrogen content of the brown alga Fucus gardneri. We found that nitrogen content was a function of (1) nitrogen supply via amount of water flow and (2) irradiance, possibly via photoinhibitory effects. This research shows that local effects, by shifting nutrient allocation, can change nitrogen content over spatial scales of centimeters. [Copyright &y& Elsevier]

In roots and mycorrhizae, the activity of phosphatases is an important parameter to characterise the efficiency of plants to access non-soluble phosphate pools in soils. We have quantified surface bound phosphatase (SBP) activity in non-mycorrhizal short roots and ectomycorrhizae of Nothofagus obliqua with image processed confocal laser scanning microscopy (LSM) using the fluorogenic substrate ELF-97 (enzyme-labelled fluorescence). Through interactive segmentation of root cells, mantle, and SBP-active centres, this method revealed a precise anatomical–physiological description of the SBP activity in cross-sections of short roots of N. obliqua, and of the mycorrhizal associations of N. obliqua with Pisolithus tinctorius and with Cenococcum geophilum in a controlled pH range (3–7).Our method revealed that the strategy of the examined species to vary the SBP activity was based primarily on the variation of the number and of the extension of the SBP-active centres. Fluctuations of the activities inside individual SBP-active centres were small. It was observed that non-mycorrhizal short roots of N. obliqua focus the distribution of SBP-active centres on the rhizodermis cells. In these cells, the SBP-active centres are distributed heterogeneously, and not preferentially in contact with the soil interface. The distribution of the SBP-active centres between the root cells and the mantle depended on the symbiont and on the pH of the buffer. The mantle hyphae of the N. obliqua–P. tinctorius associations promote direct contact between SBP-active centres and soil particles. In contrast, the mantle hyphae of N. obliqua–C. geophilum associations limit the expression of SBP-active centres to the interface between the mantle and the rhizodermis cells of N. obliqua. At this location, SBP-active centres are not in direct contact with any adjacent soil particles. Our observations of a pH-dependent activity, and of a mycorrhizal association-dependent activity of the SBP-active centres, together with the observed heterogeneity of the location of these centres relative to adjacent soil particles, challenge the general hypothesis that increased contact between mycorrhizae and soil results in higher efficiency of nutrient uptake. [Copyright &y& Elsevier]

In order to increase the cell concentration and the accumulation of astaxanthin, the effects of nutrient concentration, pH, illumination and methods of supplying nutrients were studied for the cultivation of Haematococcus pluvialis. The replacement of media to avoid the deficiency of nutrients increased the cell concentration above 1 mg-dry cell cm-3 without induction of astaxanthin accumulation. Illumination with blue light emitting diode lamps and nutrient starvation induced accumulation of astaxanthin, and the interactive effects of these two increased the astaxanthin concentration to 76 μg cm-3. [Copyright &y& Elsevier]

Abstract: Rates of tree growth in tropical forests reflect variation in life history strategies, contribute to the determination of species'' distributional limits, set limits to timber harvesting and control the carbon balance of the stands. Here, we review the resources that limit tree growth at different temporal and spatial scales, and the different growth rates and responses of functional groups defined on the basis of regeneration strategy, maximum size, and species'' associations with particular edaphic and climatic conditions. Variation in soil water availability determines intra- and inter-annual patterns of growth within seasonal forests, whereas irradiance may have a more important role in aseasonal forests. Nutrient supply limits growth rates in montane forests and may determine spatial variation in growth of individual species in lowland forests. However, its role in determining spatial variation in stand-level growth rates is unclear. In terms of growth rate, we propose a functional classification of tropical tree species which contrasts inherently fast-growing, responsive species (pioneer, large-statured species), from slow-growing species that are less responsive to increasing resource availability (shade-bearers, small-statured species). In a semi-deciduous forest in Ghana, pioneers associated with high-rainfall forests with less fertile soils, had significantly lower growth rates than pioneers that are more abundant in low-rainfall forests with more fertile soils. These results match patterns found in seedling trials and suggest for pioneers that species'' associations with particular environmental conditions are useful indicators of maximum growth rate. The effects of variation in resource availability and of inherent differences between species on stand-level patterns of growth will not be independent if the functional group composition of tropical forests varies along resource gradients. We find that there is increasing evidence of such spatial shifts at both small and large scales in tropical forests. Quantifying these gradients is important for understanding spatial patterns in forest growth rates. [Copyright &y& Elsevier]

Data from published production studies in lactating dairy cows were used to estimate relationships between silage fermentation characteristics and milk production parameters. The study used data from 47 experiments including 234 observations (treatment means). Within each experiment the silages were harvested at the same time from the same sward but using various additives. When factorial designs were used, silage data within each treatment (subexperiment) were recorded separately. Relationships between production parameters and silage fermentation parameters were analysed using mixed model regression analyses; with subexperiment within experiment as a random factor. Yields of milk, energy corrected milk (ECM), milk fat and protein decreased with increasing extent of in-silo fermentation. The effects were more profound for ECM than milk yield, because both milk fat and protein concentrations decreased (P<0.001) with increasing silage lactic acid or total acid concentrations. In most cases total acid concentration was the best single predictor of production parameters, although multiple regression equations generally explained the variation better than single regressions. Yield of ECM decreased by 18.9, 25.4 and 19.1 g per g/kg DM increase in the concentration of lactic acid, volatile fatty acids (VFA) or 1 g/kg N increase in ammonia N concentration. Multiple regression analyses also showed a greater negative effect of VFA compared to lactic acid on the yields of ECM, milk fat and protein. The best multiple equations explained between 0.25 and 0.35 of the variation in ECM, milk fat or protein yield within experiment. The effects of extent of fermentation and ammonia N on production parameters were additive. Reduced milk fat content with increasing extent of in-silo fermentation appears to be related to reduced proportion of lipogenic VFA in the rumen. Lower milk protein content for extensively fermented silages can be attributed to reduced silage DM intake and microbial protein synthesis in the rumen. Proportional decreases in the yield of milk components with increasing extent of in-silo fermentation were the smallest for lactose and the highest for milk fat. Yield of ECM increased by 0.12 kg/MJ additional metabolizable energy (ME) in response to increased DM intake with improved fermentation quality. In studies conducted in Finland the within-experiment R2 value between ME intake and ECM yield was 0.74 indicating that the effects on ECM yield were mainly derived from increased silage intake. [Copyright &y& Elsevier]

In Upper Silesia in Poland, coal is still exploited intensively and mine dump reclamation and afforestation are important environmental mitigation activities. In this study, we analysed the survival rate and foliar nutrient (N, P, K, Ca, and Mg) supply status and their quantitative relationships of two-year-old Scots pine, Norway spruce, Common oak and European beech at an early afforestation stage of a hard coal mine dump with topsoil. The conditions in the dump in the first years were particularly unfavorable for beech and spruce. The survival rate of seedlings varied between 93% for oak, 67% for pine, 30% for beech and 27% for spruce. Nutrient supply and their quantitative relationships in seedling foliage varied highly in all investigated species. The most deficient element was N; its content was lower than the accepted threshold for individual species under natural conditions. Of the soil properties analysed, electrolytic conductivity (EC) was strongly negatively correlated with foliar N and P. Thus, EC may be the factor with the highest negative effect on nutrient supply and the success of afforestation at early stages. [ABSTRACT FROM AUTHOR]

[Display omitted] • Temporal patterns of sediment OC burial over the past ~100 years were studied. • Increasing OCAR during 1880–1980 was favored by land use promoting P input. • Decreasing OCAR since 1980 was associated with enhanced OM decomposition and OC mineralization. • OC pool may be mediated under projected climate warming scenarios for deep lakes. Inland waterbodies play an important role in the global carbon cycle, acting both as carbon sources with organic carbon (OC) mineralization and as sinks with OC burial in sediments. Under recent impacts of global warming, anthropogenic land-use change and nutrient supply, however, there is a limited knowledge regarding OC dynamics in sediments of large, deep lakes especially in subtropical alpine regions. Here, we studied the patterns of OC burial and the potential regulating factors using multiple sedimentary proxies and observational records in Lugu Lake (southwest China) over the past ~100 years. Comparisons of 15 sediment cores in different areas of the lake reveal similar temporal trends in OC content and other sediment parameters, indicating coherent patterns of whole-lake sedimentary environmental change dominated by watershed human perturbation. Based on C/N ratios and δ13C org analyses, the sediment OC has primarily been autochthonous in source. OC accumulation rates (OCAR) increased during 1880–1980, from ~14 to 43 g C m−2 yr−1 in a central core (LGS), mainly resulting from elevated primary production under increased phosphorus input and soil erosion. Subsequently, OCAR decreased considerably to ~15 g C m−2 yr−1, although the phosphorus supply and lake primary productivity remained high. We infer the OCAR decline likely resulted from increased organic matter decomposition and OC mineralization in the water column because of climate warming and lake-water thermal stratification. This phenomenon might mask the positive contribution of primary production to OC burial. Our findings suggest that the commonly observed synergistically positive effects of warming and eutrophication on sediment OC burial may be impaired in deep lakes, which needs further investigations across ecological, climatic and land-use gradients. [ABSTRACT FROM AUTHOR]

• High p CO 2 and P interactively increased the abundances of Syn, Pro and PEuks. • Rising p CO 2 alone decreased the abundances of Syn, Pro and PEuks. • Elevated p CO 2 alone facilitated the NPQ NSV process significantly. • There was a strong coupling of picophytoplankton and the charge separation rates. • P enrichment masked the negative effects of OA on picophytoplankton and photosynthesis. Dynamics of picophytoplankton and photosynthesis will be inevitably impacted by changing marine environment, such as ocean acidification and nutrient supply, but related studies are very scarce. Here we cultured the picophytoplankton-dominated surface water of the oligotrophic Eastern Indian Ocean (EIO; R/V Shiyan-3 , 20 March to 18 May 2019) at two levels of p CO 2 (400 and 1000 ppm) and phosphate (0.05 and 1.50 µM) to investigate the interactive effects of elevated p CO 2 and phosphate (P) on the dynamics of picophytoplankton and photosynthetic properties. High p CO 2 and P levels interactively increased the abundances of Synechococcus , Prochlorococcus and picoeukaryotes by 33%, 18%, and 21%, respectively, of which high P level had a major promoting effect. Conversely, rising p CO 2 alone decreased their abundances by 9%, 32%, and 46%, respectively. For the photophysiological responses in relation to the combination of high p CO 2 and P levels, there was an increase in the maximum (F v /F m) and effective (F q '/F m ') photochemical efficiency, the electron transfer rates (ETR RCII) and the charge separation rates (JV PSII , an indicator of primary production), but a decrease in the non-photochemical quenching (NPQ NSV). Elevated p CO 2 alone facilitated the NPQ NSV process significantly, ultimately leading to reduced light use efficiency (e.g., F v /F m , F q '/F m ' and ETR RCII) and primary production (JV PSII). There was a strong coupling of picophytoplankton and JV PSII , suggesting the EIO primary productivity was potentially controlled by picophytoplankton. Overall, our results indicate that the negative effects caused by ocean acidification may be masked or outweighted by the role that P availability plays in regulating growth and metabolism in this oligotrophic ecosystem. [ABSTRACT FROM AUTHOR]

Abstract: The objetive of this work was to study if the addition of nutrients to the irrigation water modified ‘Manzanilla de Sevilla’ olive pulp and pit growth. The experiment was carried out during the 2003 fruit-growth period in an irrigated orchard near Seville, southern Spain. Fruit samples were taken in July and September, at 12 and 21 weeks after full bloom (AFB) respectively, in trees irrigated with (T1) or without (T0) the addition of nutrients (N–P–K). The nutrient availability of T1 fruits increased the fruit fresh and dry weight, longitudinal and equatorial diameters, and the pulp-to-pit ratio, characteristics particularly appreciated for table olives. The balance of growth between the fruit mesocarp (pulp) and endocarp (pit) was modified because those two tissues were affected differently. Mesocarp fresh weight was significantly higher at both 12 and 21 weeks AFB in the fertilized treatment, as was mesocarp dry weight at 12 weeks AFB. Neither the endocarp fresh and dry weight nor shape (the ratio of the equatorial and longitudinal diameters) was altered at either of the two studied dates. These results emphasize the importance of an appropriate fertilization management in irrigated olive orchards, particularly for table olives, and also confirm the olive endocarp as a strong sink tissue that competes with the mesocarp during early development. [Copyright &y& Elsevier]

Water temperature and food availability are two environmental factors that are widely considered to be likely determinants of recruitment success of fish stocks. However, marine environmental data are commonly of limited availability. Moreover, the mechanisms by which environmental variations may act to regulate fish recruitment remain incompletely understood, especially from the point of view of prey availability. Here we report a test of the feasibility of using simulated long-term hindcast of marine environmental data based on a physical and lower-trophic-level ecosystem data-assimilative model to investigate the impacts of water temperature and prey availability on recruitment fluctuations of the Japanese anchovy (Engraulis japonicus) in the Yellow Sea. Although observational data available for model validation were limited, the model reasonably reproduced inter-annual fluctuations of phytoplankton abundance. The model results for a 15-year period (1987–2001) indicated Japanese anchovy recruitment to have been negatively correlated with July sea surface temperature in the traditional spawning ground south of the Shandong Peninsula, while being positively correlated with near-surface biomass of small zooplankton (the predominant prey for anchovy larvae) in the central Yellow Sea during the summer period. These findings imply that the Japanese anchovy recruitment in the Yellow Sea is likely regulated during its early life stages by both water temperature and food availability. The negative temperature-recruitment relationship could be explained by the "spawning temperature optima" and "optimal growth temperature" hypotheses. Furthermore, model results indicated that inter-annual variation in the near-surface biomass of small zooplankton in the central Yellow Sea during summer is mainly regulated by nutrient supply, to which both vertical stratification and horizontal advection may make contributions. • A physical-ecological model (FVCOM-NEMURO) was developed. • FVCOM-NEMURO was used for Japanese anchovy recruitment studies in the Yellow Sea. • SST and food availability are two factors regulating anchovy recruitment. • The effect of environmental variation on anchovy recruitment was discussed. [ABSTRACT FROM AUTHOR]