The impact of boreal forest fire on climate warming

We report measurements and analysis of a boreal forest fire, integrating the effects of greenhouse gases, aerosols, black carbon deposition on snow and sea ice, and postfire changes in surface albedo. The net effect of all agents was to increase radiative forcing during the first year (34 +/- 31 Watts per square meter of burned area), but to decrease radiative forcing when averaged over an 80-year fire cycle (-2.3 +/- 2.2 Watts per square meter) because multidecadal increases in surface albedo had a larger impact than fire-emitted greenhouse gases. This result implies that future increases in boreal fire may not accelerate climate warming.     

赖氨酸发酵蛋白粉的营养价值评定及其在生长肥育猪上的应用效果研究

本研究分为2个试验,试验I评定赖氨酸发酵蛋白粉在生长猪上的营养价值;试验2研究赖氨酸发酵蛋白粉等蛋白质替代豆粕对生长肥育猪生长、胴体性状和肉品质的影响。试验1：选用（25.0±1.1）妇杜×长×大三元杂交猪12头进行消化代谢试验,随机分为2组,每组6个重复,每个重复1头猪,分别饲喂无氮日粮和以赖氨酸发酵蛋白粉作为唯一蛋白质源的试验日粮,预试期4d,正试期4d。试验2：选用（41.7±3.9）kg杜×长×大三元杂交猪100头进行饲养试验,随机分为4组,每组5个重复,每个重复5头猪。I组为对照组,饲喂基础日粮;Ⅱ、Ⅲ和Ⅳ组分别为饲喂赖氨酸发酵蛋白粉等蛋白质替代10％、25％、50％豆粕的试验日粮,体重达100kg左右结束。消化代谢试验结果表明：赖氨酸发酵蛋白粉消化能为12.85MJ·kg^-1,代谢能为11.80MJ·kg^-1。总氨基酸含量为47.38％,总氨基酸的回肠表观消化率、真消化率分别为66.95％和70.52％,赖氨酸和蛋氨酸的回肠表现消化率、真消化率分别为72.00％、75.14％和59.37％、64.52％。试验结果表明：与对照组相比,在生长期和全期,Ⅳ组平均日增重显著降低（P〈0.05）,料重比显著升高（P〈0.05）;在肥育期,Ⅳ组平均日采食量显著增加（P〈0.05）,料重比显著升高（P〈0.05）,生长期和肥育期,Ⅳ组氮消化率、氮生物学效价显著降低（P〈0.05）。Ⅳ组背膘厚显著增加（P〈0.05）,眼肌面积和肌肉保水能力显著降低（P〈0.05）。由此得出,与豆粕相比,赖氨酸发酵蛋白粉的粗蛋白质和脂肪含量较高,非蛋白氮比例大,氨基酸消化率低。蛋白质替代10％和25％豆粕对40-100kg的生长肥育猪生产性能、胴体性状和肉品质均无影响,可作为饲粮中的新型蛋白质原料。     

Assessing the Antagonistic Potential and Antibiotic Resistance of Actinomycetes Isolated from Two Zheltozems of Southeastern China

Forty streptomycete strains have been isolated into pure culture from two eroded zheltozems (yellow soils) of the Fujian province. Their antagonistic activities and contributions to the formation of soil resistome have been characterized. The estimation of the antimicrobial effect of natural isolates allowed revealing 6 strains simultaneously inhibiting the growth of the fungi Fusarium oxisporum, Alternaria alternata, Paecilomyces sp., Trichoderma sp., and Candida albicans. One strain (Streptomyces aburaviensis F2-6) with a wide range of antifungal actions was also active against the bacteria Pseudomonas putuda, P. fluorescens, P. sepacia, Streptococcus sp., and Escherichia coli. It has been shown that the share of isolates with a wide range of antimicrobial effects (44%) and a high antagonistic activity (77%) in zheltozem of the urban Zhangzhou district is significantly higher than in the soil of the village of Hongkeng (22 and 39%, respectively). According to the resistome concept, determinants of resistance to antibiotics first appeared in their producers; they can be transmitted to other bacteria in the soil due to horizontal drift. Tests of streptomycetes for resistance to antibiotics with different acting mechanisms (inhibitors of the synthesis of cytoderm, protein, and metabolic pathways) has shown that the share of cultures with multiple resistance in zheltozems does not exceed 25–31%. No resistance to all of the studied antibiotics is characteristic of 15–16% of the strains isolated from zheltozems. The obtained data can be used for assessing the risks related to the transfer of antibiotic resistance genes from the environment to clinically valuable pathogenic species.     

Seasonal pattern of denitrification under an irrigated wheat-maize cropping system fertilized with urea and farmyard manure in different combinations

Under semiarid subtropical field conditions, denitrification was measured from the arable soil layer of an irrigated wheat–maize cropping system fertilized with urea at 50 or 100 kg N ha^–1 year^–1 (U₅₀ and U₁₀₀, respectively), each applied in combination with 8 or 16 t ha^–1 year^–1 of farmyard manure (FYM) (F₈ and F₁₆, respectively). Denitrification was measured by acetylene inhibition/soil core incubation method, also taking into account the N₂O entrapped in soil cores. Denitrification loss ranged from 3.7 to 5.7 kg N ha^–1 during the growing season of wheat (150 days) and from 14.0 to 30.3 kg N ha^–1 during the maize season (60 days). Most (up to 61%) of the loss occurred in a relatively short spell, after the presowing irrigation to maize, when the soil temperature was high and a considerable NO₃^–-N had accumulated during the preceding 4-month fallow; during this irrigation cycle, the lowest denitrification rate was observed in the treatment receiving highest N input (U₁₀₀+F₁₆), mainly because of the lowest soil respiration rate. Data on soil respiration and denitrification potential revealed that by increasing the mineral N application rate, the organic matter decomposition was accelerated during the wheat-growing season, leaving a lower amount of available C during the following maize season. Denitrification was affected by soil moisture and by soil temperature, the influence of which was either direct, or indirect by controlling the NO₃^– availability and aerobic soil respiration. Results indicated a substantial denitrification loss from the irrigated wheat–maize cropping system under semiarid subtropical conditions, signifying the need of appropriate fertilizer management practices to reduce this loss.     

Soil Organic Carbon Density in Hebei Province, China：Estimates and Uncertainty

In order to improve the precision of soil organic carbon (SOC) estimates, the sources of uncertainty in soil organic carbon density (SOCD) estimates and SOC stocks were examined using 363 soil profiles in Hebei Province, China, with three methods: the soil profile statistics (SPS), GIS-based soil type (GST), and kriging interpolation (KI). The GST method, utilizing both pedological professional knowledge and GIS technology, was considered the most accurate method of the three estimations, with SOCD estimates for SPS 10% lower and KI 10% higher. The SOCD range for GST was 84% wider than KI as KI smoothing effect narrowed the SOCD range. Nevertheless, the coefficient of variation for SOCD with KI (41.7%) was less than GST and SPS. Comparing SOCD‘s lower estimates for SPS versus GST, the major sources of uncertainty were the conflicting area of proportional relations. Meanwhile, the fewer number of soil profiles and the necessity of using the smoothing effect with KI were its sources of uncertainty. Moreover, for local detailed variations of SOCD, GST was more advantageous in reflecting the distribution pattern than KI.     

In vivo bioinsecticidal activity toward Ceratitis capitata (fruit fly) and Callosobruchus maculatus (cowpea weevil) and in vitro bioinsecticidal activity toward different orders of insect pests of a trypsin inhibitor purified from tamarind tree (Tamarindus indica) seeds

A proteinaceous inhibitor with high activity against trypsin-like serine proteinases was purified from seeds of the tamarind tree (Tamarindus indica) by gel filtration on Shephacryl S-200 followed by a reverse-phase HPLC Vidac C18 TP. The inhibitor, called the tamarind trypsin inhibitor (TTI), showed a Mr of 21.42 kDa by mass spectrometry analysis. TTI was a noncompetitive inhibitor with a Ki value of 1.7 x 10(-9) M. In vitro bioinsecticidal activity against insect digestive enzymes from different orders showed that TTI had remarkable activity against enzymes from coleopteran, Anthonomus grandis (29.6%), Zabrotes subfasciatus (51.6%), Callosobruchus maculatus (86.7%), Rhyzopertha dominica(88.2%), and lepidopteron, Plodia interpuncptella (26.7%), Alabama argillacea (53.8%), and Spodoptera frugiperda (75.5%). Also, digestive enzymes from Diptera, Ceratitis capitata (fruit fly), were inhibited (52.9%). In vivo bioinsecticidal assays toward C. capitata and C. maculatus larvae were developed. The concentration of TTI (w/w) in the artificial seed necessary to cause 50% mortality (LD50) of larvae was 3.6%, and that to reduce mass larvae by 50.0% (ED50) was 3.2%. Furthermore, the mass C. capitata larvae were affected at 53.2% and produced approximately 34% mortality at a level of 4.0% (w/w) of TTI incorporated in artificial diets.     

Chemical composition and structural features of the macromolecular components of plantation Acacia mangium wood

The wood of Acacia mangium, a prominent fast-growing plantation species used in the pulp-and-paper industry and, so far, poorly investigated for its chemical structure, was submitted to a detailed characterization of its main macromolecular components. Lignin (28% wood weight) isolated by mild acidolysis and characterized by permanganate oxidation, 1H and 13C NMR, and GPC, showed a very low content of syringylpropane-derived units (S:G:H of 48:49:3), a high degree of condensation, a low content of beta-O-4 ( approximately 0.40-0.43 per C6) structures, and a Mw of 2230. Glucuronoxylan (14% wood weight) isolated by alkaline (KOH) or by dimethyl sulfoxide extraction was characterized by methylation analysis, 1H NMR, and GPC. About 10% of the xylopyranose (Xylp) units constituting the linear backbone were substituted at O-2 with 4-O-methylglucuronic acid residues. Almost half of the Xylp units (45%) were O-2 (18%), O-3 (24%) or O-2,3 (3%) acetylated. X-ray diffraction analysis of cellulose (46% wood weight), isolated according to the Kürschner-Hoffer method, showed a degree of crystallinity of 67.6%.     

Evaluation of the antioxidant capacity of individual phenolic compounds in virgin olive oil

Virgin olive oil has a high resistance to oxidative deterioration due to its tryacylglycerol composition low in polyunsaturated fatty acids and due to the presence of a group of phenolic antioxidants composed mainly of polyphenols and tocopherols. We isolated several phenolic compounds of extra virgin olive oil (phenyl-ethyl alcohols, lignans, and secoiridoids) by semipreparative high-performance liquid chromatography (HPLC) and identified them using ultraviolet, atmospheric pressure chemical ionization, and electrospray ionization MS detection. The purity of these extracts was confirmed by analytical HPLC using two different gradients. Finally, the antioxidant capacity of the isolated compounds was evaluated by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl radical, by accelerated oxidation in a lipid model system (OSI, oxidative stability instrument), and by an electrochemical method.     

Environmental change and its impacts on human settlement in the Yangtze Delta, P.R. China

Archaeological excavations and environment–archaeology studies over many years in the Yangtze Delta region have provided exceptional information about climatic variations, growth and demise of human civilization and human–environment interactions. The archaeological excavations show that the cultural layers of the Neolithic sites are interrupted by barren layers without any cultural relics (so-called cultural interruptions), which may be the result of harsh environmental conditions (arid, flooding, extreme cold or warmth). Temporal and spatial analyses of ¹⁴C-dates for buried trees, peat, shell ridges, and Neolithic sites show that environmental changes are responsible for the rise and fall of human civilization. The progress of human civilization was interrupted at least 5 times in the Yangtze Delta, matching 5 periods of high sea level, peat accumulation, and burial of trees. The collapse of the Liangzhu culture about 4000 BP was followed by the less-developed Maqiao culture and resulted from extreme environmental and hydrological conditions such as floods.     

Land Disposal of Centrate from Biosolids Production

Arid land and riparian plants were irrigated with a liquid wastewater stream (centrate) from biosolids production at a municipal sewage treatment facility. Centrate containing approximately 1000 mg/l ammonia nitrogen was diluted with Tucson city tap water to provide treatments of 2.5, 5, 10, 25, 50, and 100% centrate, along with a dilution water control. Plants grown in 19-l containers in a greenhouse were irrigated daily with 6.7 l of solution over a 7-week period. All species exhibited a fertilizing effect at concentrations up to 5 and 10% centrate, equivalent to approximately 50 and 100 mg/l NH₃–N, but then inhibitory above 100 mg/l. No plants survived on the 50 or 100% treatments. If centrate were to be diverted from the wastewater facility to be disposed of on the land, it was estimated that the total nitrogen content of the biosolids produced by the plant would be reduced by 11%. This reduction would have only a small impact on the value of the biosolids for soil amendment applications.