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1.
This study shows that Vochysia guatemalensis tree plantations were associated with enhanced soil biotic and abiotic characteristics in previously cleared forests in the northern zone of Costa Rica, suggesting the possible use of this practice as a restoration strategy for local land owners. Soil samples from a primary forest, secondary forest, and a 13‐year‐old plantation of V. guatemalensis had greater relative abundances of DNA sequences of microbial genera critical for carbon‐use (C‐use) efficiency (i.e. the saprobe, complex C and wood rot/lignin decomposer fungi, and bacterial lignin and other complex C degraders), and greater levels of total organic carbon, C‐biomass, and microbial quotients as indicators of enhanced C‐use efficiency, than found in soils of adjacent 5‐year‐old V. guatemalensis plantations and abandoned non‐productive pasture/grasslands (GRs). The major research conclusions were that (1) conversion of forested land into abandoned pasture/GRs decreased the C‐use efficiency in the soils and the microbial groups associated with C‐use efficiency; (2) soils in plantations of V. guatemalensis were associated with increased abundances of the DNA of these same microbial groups and enhanced C‐use efficiency; (3) DNA‐based taxonomic analysis of microbes and analysis of the microbial quotient values can be used to monitor soil ecosystems for assessment of the efficacy of restoration activities. Thus, planting V. guatemalensis on damaged lands in the Maquenque National Wildlife Refuge should be encouraged to provide a sustainable forestry crop that can be harvested rotationally, while improving soil ecosystem health and reducing the pressure to harvest other forest sites.  相似文献   

2.
1. Broad‐scale assessment of stream health is often based on correlative relationships between catchment land‐use categories and measurements of stream biota or water chemistry. Few studies have attempted to characterise the response curves that describe how measures of ecosystem function change along gradients of catchment land use, or explored how these responses vary at broad spatial scales. 2. In autumn 2008, we conducted a survey of 84 streams in three bioregions of New Zealand to assess the sensitivity of functional indicators to three land‐use gradients: percentage of native vegetation cover, percentage of impervious cover (IC) and predicted nitrogen (N) concentration. We examined these relationships using general linear models and boosted regression trees to explore monotonic, non‐monotonic and potential threshold components of the response curves. 3. When viewing the responses to individual land‐use gradients, four of five functional indicators were positively correlated with the removal of native vegetation cover and N. In general, weaker and less responsive models were observed for the IC gradient. An analysis of the response to multiple stressors showed δ15N of primary consumers and gross primary productivity (GPP) to be the most responsive functional indicators to land‐use gradients. The multivariate models identified thresholds for change in the relationship between the functional indicators and all three land‐use gradients. Apparent thresholds were <10%IC, between 40 and 80% loss of native vegetation cover and at 0.5 and 3.2 mg L?1 N. 4. The strength of regression models and the nature of the response curves suggest that measures of ecosystem function exhibit predictable relationships with land use. Furthermore, the responses of functional indicators varied little among three bioregions. This information provides a strong argument for the inclusion of functional indicators in a holistic assessment of stream health.  相似文献   

3.
In the present work, a simple chemiluminescence (CL) method coupled with flow‐injection analysis for the evaluation of antioxidant activity of 5′‐nucleotides (5′‐AMP, 5′‐CMP, 5′‐GMP, 5′‐UMP) was proposed. It is based on inhibition effect of the studied substances on CL emission of luminol–potassium ferricyanide–pyrogallol. Experiments were performed to evaluate the nature of the inhibition by 5′‐nucleotides of the CL reaction and their antioxidant activities. Based on the experimental results, it was observed that 5′‐nucleotides are available antioxidants that could effectively scavenge superoxide anion free radicals in a concentration‐dependent way. This will provide a basis for further development of the use of nucleotides. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

4.
Decomposition of phenyl acridinium-9-carboxylate is monitored using electrogenerated chemiluminescence in a flow system. The formation of the pseudobase from the acridinium ester [AE] is described by rate = k1[AE] + k1[AE][OH?]0.5, where k1 = 0.020 ± 0.006 s?1 and k1 = 2.1 ± 0.8 (L/mol)?0.5 s?1. Irreversible decomposition of the pseudobase is described by rate = k2[AE][OH?], where k2 = 20.1 ± 3.8 (L/mol s). These kinetic equations, plus measurement of variation in emission intensity for constant acridinium ester concentration, are used to predict the resulting emission intensity v. pH behaviour given various contact times (in the 0.25 to 25 s range) for the acridinium ester to be in an alkaline solution prior to initiation of the chemiluminescence reaction.  相似文献   

5.
In this study, the possible uses of glassworts as potential food ingredients and their antiproliferative activity against colorectal adenocarcinoma cells together with their antioxidant and phytochemical profiles were investigated for the first time. MeOH extracts of five different taxa collected from different localities were screened for their antioxidant capacities by DPPH (IC50 2.91 – 5.49 mg/ml) and ABTS (24.4 – 38.5 μmol TE/g extract) assays. Salicornia freitagii exhibited the highest DPPH radical scavenging activity. LC/MS/MS analysis displayed that vanillic acid and p‐coumaric acid were two main phenolic compounds in the extract. Salicornia freitagii extracts also exhibited high antiproliferative activity against HT‐29 (IC50 1.67 mg/ml) and Caco‐2 (IC50 3.03 mg/ml) cells for 72 h. Mineral analysis indicated that all the species with different proportions of elemental components contained high amount of cations. These results indicate that investigated glassworts, with their high phenolic and mineral contents and also notable antioxidant and cytotoxic properties, may be utilized as a promising source of therapeutics.  相似文献   

6.
Purpose

The main purpose of this review is to describe the state of the art of social impact assessment with a focus on mobility services. Whereas the use phase plays an important role for the assessment of services in general, the evaluation of the use phase has been underrepresented in previous social life cycle assessment studies. For that reason, particular attention has been paid to indicators, which allow the assessment of social impacts during the use phase of mobility services.

Methods

Continuous efforts to mitigate climate change and to improve quality of life in cities result in new mobility solutions based on collective use. This will have a huge impact on our society transforming the use of vehicles. In order to better understand the implications for cities, society and the automotive industry, it is essential to evaluate the social impact generated along a product life cycle with particular attention to the use phase. To reach the goal, a systematic literature review was carried out with a focus on social indicators that allow assessing use phase impacts of mobility services. The indicators were analysed and allocated to stakeholder groups. Based on the analysis, a core set of indicators is proposed under consideration of data availability.

Results and discussion

Based on the selected search strings, 51 publications were selected for the literature review, including 579 social indicators. The analysis revealed a wide variety and diversity of indicators that are trying to measure the same aspect. The allocation to the respective stakeholder groups showed that most of the indicators (36%) evaluate impacts regarding the stakeholder group local community. The majority of analysed indicators are of quantitative nature (63%). Nevertheless, a clear assessment method was often missing in the respective publications. Therefore, for the core set of indicators, an assessment method is proposed for every indicator.

Conclusions

The results from this study can help practitioners as well as researchers in the field of urban mobility assessment as it systematically analyses social sustainability aspects. The presented data gives an overview of various indicators that are suggested in other publications, and the proposed core set of indicators can be used to evaluate different mobility services in further research.

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7.
Summary Population admixture can be a confounding factor in genetic association studies. Family‐based methods ( Rabinowitz and Larid, 2000 , Human Heredity 50, 211–223) have been proposed in both testing and estimation settings to adjust for this confounding, especially in case‐only association studies. The family‐based methods rely on conditioning on the observed parental genotypes or on the minimal sufficient statistic for the genetic model under the null hypothesis. In some cases, these methods do not capture all the available information due to the conditioning strategy being too stringent. General efficient methods to adjust for population admixture that use all the available information have been proposed ( Rabinowitz, 2002 , Journal of the American Statistical Association 92, 742–758). However these approaches may not be easy to implement in some situations. A previously developed easy‐to‐compute approach adjusts for admixture by adding supplemental covariates to linear models ( Yang et al., 2000 , Human Heredity 50, 227–233). Here is shown that this augmenting linear model with appropriate covariates strategy can be combined with the general efficient methods in Rabinowitz (2002) to provide computationally tractable and locally efficient adjustment. After deriving the optimal covariates, the adjusted analysis can be carried out using standard statistical software packages such as SAS or R . The proposed methods enjoy a local efficiency in a neighborhood of the true model. The simulation studies show that nontrivial efficiency gains can be obtained by using information not accessible to the methods that rely on conditioning on the minimal sufficient statistics. The approaches are illustrated through an analysis of the influence of apolipoprotein E (APOE) genotype on plasma low‐density lipoprotein (LDL) concentration in children.  相似文献   

8.
A series of novel esters and amides was synthesized on the basis of para‐coumaric acid containing isobornyl groups in ortho‐positions relative to the phenolic hydroxy group. Antioxidant properties of the obtained compounds were evaluated and compared on in vitro models: radical‐scavenging ability, antioxidant activity on a substrate containing the lipids of animal brain, cytotoxicity of red blood cells, antioxidant and membrane‐protective properties on the model of oxidative red blood cells hemolysis. Statistically significant relationship was established between the antioxidant activity of the studied compounds in model system containing animal lipids and the parameters reflecting their antioxidant properties on the model of H2O2‐induced hemolysis of red blood cells. It was determined that an amide with a morpholine fragment has the highest antioxidant activity. The specified derivative significantly surpassed the reference substances (parent acid, BHT) and was not inferior to the effective antioxidant 2,6‐diisobornyl‐4‐methylphenol in terms of its properties.  相似文献   

9.
Using 2,4,6‐tris‐(2‐pyridyl)‐s‐triazine (TPTZ) as a neutral ligand, and p‐hydroxybenzoic acid, terephthalic acid and nitrate as anion ligands, five novel europium complexes have been synthesized. These complexes were characterized using elemental analysis, rare earth coordination titrations, UV/vis absorption spectroscopy and infrared spectroscopy. Luminescence spectra, luminescence lifetime and quantum efficiency were investigated and the mechanism discussed in depth. The results show that the complexes have excellent emission intensities, long emission lifetimes and high quantum efficiencies. The superior luminescent properties of the complexes may be because the triplet energy level of the ligands matches well with the lowest excitation state energy level of Eu3+. Moreover, changing the ratio of the ligands and metal ions leads to different luminescent properties. Among the complexes, Eu2(TPTZ)2(C8H4O4)(NO3)4(C2H5OH)·H2O shows the strongest luminescence intensity, longest emission lifetime and highest quantum efficiency. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

10.
Endomorphin 1 (EM1), an endogenous µ‐opioid receptor agonist, acts as a free radical scavenger in vitro and an antioxidant in vivo. The modification of EM1 by ROS and the properties of the OM attracted our attention. In vitro assays were performed via RP‐HPLC, spectrophotometric measurements, EPR and amino acid analysis, Schmorl's reaction to define the formation of melanin‐like compounds transformed from EM1, collectively named EM1–melanin and by solubility assay, radioligand‐binding assay, NADH oxidation, superoxide anion scavenging assay to study some physical and chemical properties of EM1–melanin. Possible pathways of the formation of EM1–melanin were proposed. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.  相似文献   

11.
UV‐induced synthesis/accumulation of photoprotective pigments and antioxidant activity were investigated in the hot‐spring cyanobacterium Leptolyngbya cf. fragilis. The results indicated that UV radiation may induce biosynthesis of carotenoids, allophycocyanin, phycoerythrin, and scytonemin while phycocyanin degrades in response to longtime UV radiation. Moreover, pigment composition of L. cf. fragilis was significantly altered with increasing UV radiation times, probably due to destruction and resynthesis of accessory pigments as an adaptation strategy to UV stress. The in vitro antioxidant analysis of different extracts of UV treated cyanobacteria exhibited concentration‐dependent antioxidant activity. Ethyl acetate extract of 72 h UV treatment showed maximum total antioxidant activity (IC50 = 71.73 ± 5.3 μg mL?1) followed by ethyl acetate control (non‐UV irradiated) extract (IC50 = 109.43 ± 2.76 μg mL?1). This is the first report for the UV‐induced synthesis of photoprotective pigments and their antioxidant activity in L. cf. fragilis.  相似文献   

12.
As governments elaborate strategies to counter climate change, there is a need to compare the different options available on an environmental basis. This study proposes a life cycle assessment framework integrating the Lashof accounting methodology, which enables the assessment and comparison of different carbon mitigation projects (e.g., biofuel use, a sequestering plant, an afforestation project). The Lashof accounting methodology is chosen amid other methods of greenhouse gas (GHG) emission characterization for its relative simplicity and capability to characterize all types of carbon mitigation projects. Using the unit of megagram‐year (Mg‐year), which accounts for the mass of GHGs in the atmosphere multiplied by the time it stays there, the methodology calculates the cumulative radiative forcing caused by GHG emission within a predetermined time frame. Basically, the developed framework uses the Mg‐year as a functional unit and isolates impacts related to the climate mitigation function with system expansion. The proposed framework is demonstrated with a case study of tree ethanol pathways (maize, sugarcane, and willow). The study shows that carbon mitigation assessment through life cycle assessment is possible and that it could be a useful tool for decision makers, as it can compare different projects regardless of their original context. The case study reveals that system expansion, as well as each carbon mitigation project's efficiency at reducing carbon emissions, are critical factors that have a significant impact on the results. Also, the framework proves to be useful for treating land‐use change emissions, as they are considered through the functional unit.  相似文献   

13.
We aimed in the present study to investigate the chemical composition, the antioxidant capacities as well as the in vitro fermentation properties of Salvia officinalis leaves aqueous extract (SOLAE) grown in four regions of northwestern Tunisia. Our data firstly indicated a spatial variation (P<0.05) in condensed tannins, total lipids, polyphenols and flavonoids contents. The HPLC‐PDA‐ESI‐MS/MS‐LC/HR‐ESI‐MS technique allowed to the identification of 13 phenolic compounds and showed that protocatechuic acid is the major constituent of the plant leaves grown in Tabarka, Ain Draham and Testour. The SOLAE of the plant grown in Tabarka presents the most potent scavenging activity against DPPH radical and had the highest percentage of inhibition. More importantly, we found in the present study that the digestibility of dry matter and in vitro fermentation showed a significant variation between the regions and the animal species. Also, we showed a very positive correlation between antioxidant properties and phenolic compounds contents. In conclusion, we suggest that SOLAE had potential beneficial effects owing in part to its antioxidant and ROS scavenging activities. Therefore, S. officinalis can be proposed as an additive food for animals’ nutrition and health.  相似文献   

14.
Sub‐Saharan Africa (SSA) could face food shortages in the future because of its growing population. Agricultural expansion causes forest degradation in SSA through livestock grazing, reducing forest carbon (C) sinks and increasing greenhouse gas (GHG) emissions. Therefore, intensification should produce more food while reducing pressure on forests. This study assessed the potential for the dairy sector in Kenya to contribute to low‐emissions development by exploring three feeding scenarios. The analyses used empirical spatially explicit data, and a simulation model to quantify milk production, agricultural emissions and forest C loss due to grazing. The scenarios explored improvements in forage quality (Fo), feed conservation (Fe) and concentrate supplementation (Co): FoCo fed high‐quality Napier grass (Pennisetum purpureum), FeCo supplemented maize silage and FoFeCo a combination of Napier, silage and concentrates. Land shortages and forest C loss due to grazing were quantified with land requirements and feed availability around forests. All scenarios increased milk yields by 44%–51%, FoCo reduced GHG emission intensity from 2.4 ± 0.1 to 1.6 ± 0.1 kg CO2eq per kg milk, FeCo reduced it to 2.2 ± 0.1, whereas FoFeCo increased it to 2.7 ± 0.2 kg CO2eq per kg milk because of land use change emissions. Closing the yield gap of maize by increasing N fertilizer use reduced emission intensities by 17% due to reduced emissions from conversion of grazing land. FoCo was the only scenario that mitigated agricultural and forest emissions by reducing emission intensity by 33% and overall emissions by 2.5% showing that intensification of dairy in a low‐income country can increase milk yields without increasing emissions. There are, however, risks of C leakage if agricultural and forest policies are not aligned leading to loss of forest to produce concentrates. This approach will aid the assessment of the climate‐smartness of livestock production practices at the national level in East Africa.  相似文献   

15.
Evaluating the sustainability of the urban water cycle is not straightforward, although a variety of methods have been proposed. Given the lack of integrated data about sewers, we applied the eco‐efficiency approach to two case studies located in Spain with contrasting climate, population, and urban and sewer configurations. Our goal was to determine critical variables and life cycle stages and provide results for decision making. We used life cycle assessment and life cycle costing to evaluate their environmental and economic impacts. Results showed that both cities have a similar profile, albeit their contrasting features, that is, operation and maintenance, was the main environmental issue (50% to 70% of the impacts) and pipe installation registered the greatest economic capital expenditure (70% to 75%) due to labor. The location of the wastewater treatment plant (WWTP) is an essential factor in our analysis mainly due to the topography effects (e.g., the annual pump energy was 13 times greater in Calafell). Using the eco‐efficiency portfolio, we observed that sewers might be less eco‐efficient than WWTPs and that we need to envision their design in the context of an integrated WWTP‐sewer management to improve sewer performance. In terms of methodological approach, the bidimensional nature of eco‐efficiency enables the benchmarking of product systems and might be more easily interpreted by the general public. However, there are still some constraints that should be addressed to improve communication, such as the selection of indicators discussed in the article.  相似文献   

16.
In this study, we investigated the phenolic composition of the crude extract (MeOH 80 %) of Alnus cordata (Loisel .) Duby stem bark (ACE) and its antioxidant and skin whitening properties. RP‐LC‐DAD analysis showed a high content of hydroxycinnamic acids (47.64 %), flavanones (26.74 %) and diarylheptanoids (17.69 %). Furthermore, ACE exhibited a dose‐dependent antioxidant and free‐radical scavenging activity, expressed as half‐maximal inhibitory concentration (IC50): Oxygen radical absorbance capacity (ORAC, IC50 1.78 μg mL?1)>Trolox equivalent antioxidant capacity (TEAC, IC50 3.47 μg mL?1)>2,2‐Diphenyl‐1‐picrylhydrazyl (DPPH, IC50 5.83 μg mL?1)>β‐carotene bleaching (IC50 11.58 μg mL?1)>Ferric reducing antioxidant power (FRAP, IC50 17.28 μg mL?1). Moreover, ACE was able to inhibit in vitro tyrosinase activity (IC50 77.44 μg mL?1), l ‐DOPA auto‐oxidation (IC50 39.58 μg mL?1) and in an in vivo model it exhibited bleaching effects on the pigmentation of zebrafish embryos (72 h post fertilization) without affecting their development and survival. In conclusion, results show that A. cordata stem bark may be considered a potential source of agents for the treatment of skin disorders due to its bleaching properties and favorable safety profiles, associated to a good antioxidant power.  相似文献   

17.
In the present work, the essential oils and volatiles from flowers, leaves, and stems of Salvia limbata obtained using microwave‐assisted hydrodistillation, solvent‐free microwave extraction, headspace‐assisted analysis, and headspace‐solid phase microextraction have been characterized for the first time. The results have been also compared with those from traditional separation techniques involving hydrodistillation and steam distillation. Regardless of some common compounds in all of the profiles, some dissimilarities were noted due to the use of different extracting approaches. Taking into account the chemical categories, sesquiterpene hydrocarbons were found as the most represented group of natural compounds contributing to the chemical profiles. It was also noted that the methanol extracts obtained from the flowers of Sallimbata showed a desirable antioxidant activity, comparable to the standard antioxidant butylated hydroxytoluene. Furthermore, using the disc diffusion and broth microdilution methods, all the tested bacteria demonstrated weak to moderate and moderate to strong sensibilities to the MeOH extracts obtained from different plant parts of Sallimbata.  相似文献   

18.
European oaks have been reported to emit isoprene or monoterpenes derived from recently fixed photosynthetic carbon. The emission type is plant species specific and can be used as chemo‐taxonomic marker. In the present article the isoprenoid biochemical properties of mature Quercus × turneri‘Pseudoturneri’ hybrids resulting from a crossing of a Mediterranean evergreen monoterpene‐emitting species (subgenus Sclerophyllodrys; Quercus ilex L.) and an isoprene‐emitting deciduous oak species (subgenus Lepidobalanus; Quercus robur L.) are described. Both species are compared with respect to the capacity for isoprenoid synthesis and the actual isoprenoid emission pattern of different tree‐types. The analysis showed that the oak hybrid combines properties of both parental species. Furthermore, it could be shown that the enzyme activities of isoprene synthase and monoterpene synthases are reflected in the isoprenoid emission pattern of the hybrids as well as in the observed emission rates.  相似文献   

19.
Photoactive perovskite semiconductors are highly tunable, with numerous inorganic and organic cations readily incorporated to modify optoelectronic properties. However, despite the importance of device reliability and long service lifetimes, the effects of various cations on the mechanical properties of perovskites are largely overlooked. In this study, the cohesion energy of perovskites containing various cation combinations of methylammonium, formamidinium, cesium, butylammonium, and 5‐aminovaleric acid is reported. A trade‐off is observed between the mechanical integrity and the efficiency of perovskite devices. High efficiency devices exhibit decreased cohesion, which is attributed to reduced grain sizes with the inclusion of additional cations and PbI2 additives. Microindentation hardness testing is performed to estimate the fracture toughness of single‐crystal perovskite, and the results indicated perovskites are inherently fragile, even in the absence of grain boundaries and defects. The devices found to have the highest fracture energies are perovskites infiltrated into a porous TiO2/ZrO2/C triple layer, which provide extrinsic reinforcement and shielding for enhanced mechanical and chemical stability.  相似文献   

20.
The chemical industry has made a contribution to modern society by providing cost‐competitive products for our daily use. However, it now faces a serious challenge regarding environmental pollutions and greenhouse gas emission. With the rapid development of molecular biology, biochemistry, and synthetic biology, industrial biotechnology has evolved to become more efficient for production of chemicals and materials. However, in contrast to chemical industries, current industrial biotechnology (CIB) is still not competitive for production of chemicals, materials, and biofuels due to their low efficiency and complicated sterilization processes as well as high‐energy consumption. It must be further developed into “next‐generation industrial biotechnology” (NGIB), which is low‐cost mixed substrates based on less freshwater consumption, energy‐saving, and long‐lasting open continuous intelligent processing, overcoming the shortcomings of CIB and transforming the CIB into competitive processes. Contamination‐resistant microorganism as chassis is the key to a successful NGIB, which requires resistance to microbial or phage contaminations, and available tools and methods for metabolic or synthetic biology engineering. This review proposes a list of contamination‐resistant bacteria and takes Halomonas spp. as an example for the production of a variety of products, including polyhydroxyalkanoates under open‐ and continuous‐processing conditions proposed for NGIB.  相似文献   

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