Characterization of Placic Horizons in Ironstone Soils of Louisiana, USA

Placic horizons, defined as thin, wavy, hardened layers of iron and organic matter, are rare within the United States, occurring only in Washington, Alaska, and Hawaii. While ironstone is common in many soils of the southeastern United States, it is not known to contain appreciable organic matter. As a pilot study evaluating the justification for a larger study on ironstone in Louisiana, a 40 m lateral exposure with suspected placic horizons was evaluated in Vernon Parish, Louisiana. Results of laboratory analysis show elevated levels of iron and organic matter in the suspect horizons that meet the criteria of placic horizons as defined by the Soil Survey Staff. Based on the results of this study, additional evaluation of multiple pedons with similar features is warranted. Should additional pedons demonstrate similar properties, a new great group of 'Petrudepts' would be needed to describe both the placic horizons in the pedon and the udic moisture regime in which they occur.

Bio-Based Paths to Prosperity for Small and Medium Forest Landowners: A Pilot Study in Southwest Louisiana

Forest biomass has great potential as a biofuel feedstock, but information on forest owner perceptions of using forest biomass to produce bioenergy is lacking. In this case study, we surveyed 3500 small to medium private forest landowners in southwestern Louisiana to better understand their attitudes and perceptions towards harvesting forest biomass for bioenergy production. Results indicate that landowners: 1) were positive about utilizing biomass for bioenergy, 2) believe viable biomass conversion technologies exist, 3) had antagonistic or neutral attitudes towards some technological, economic, and policy issues associated with using forest biomass for bioenergy due in part to lack of information or knowledge, and 4) felt biomass is a low-value product compared to traditional products. Landowners’ perceptions of participating in bio-based activities and markets vary among age and ownership size, and 51% of forest landowners were willing to participate in management activities specifically geared for bioenergy production.

Selection,effective dominance,and completeness of Cry1A.105/Cry2Ab2 dual-protein resistance in Helicoverpa zea(Boddie)(Lepidoptera:Noctuidae)

In the U.S.,Helicoverpa zea(Boddie)is a major pest targeted by both transgenic maize and cotton expressing Bacillus thuringiensis(Bt)proteins.Resistance of insect to Bt maize and cotton containing cry1A and cry2A genes has widely occurred in the U.S.In this study,two trials were performed to investigate larval survival and development of a Cry1A.105/Cry2Ab2 dual-protein resistant(VT2P-RR),a susceptible,and an F1 heterozygous(VT2P-RS)populations of H.zea on ears of nine Bt and three non-Bt maize hybrids.The Bt maize hybrids evaluated represent five common pyramided traits expressing two or three of the Cry1A.105,Cry1Ab,Cry1F,Cry2Ab2,and Vip3Aa20 proteins.In the laboratory,neonates of the three H.zea populations were inoculated on silks of ears collected from maize at R1-R2 plant stages;and larval survivorship was checked 10 d after neonate release.All three insect populations survived normally on non-Bt maize ears.Varied numbers of VT2P-RR and VT2P-RS survived on ears of Cry1A.105/Cry2Ab2 maize,while all larvae of the three populations died or could not develop on ears of Vip3Aa20-expressing maize.The results demonstrated that the dual-protein resistant H.zea was not cross-resistant to Vip3Aa20-expressing maize,and thus traits with vip3Aa20 gene should be effective to manage Cry1A.105/Cry2Ab2-resistant H.zea.The resistance in VT2P-RR was determined to be incomplete on Cry1A.105/Cry2Ab2 maize.The effective dominance levels varied greatly,from recessive to incompletely dominant,depending on maize hybrids and trials,suggesting that proper selection of maize hybrids could be important for mitigating the Cry1A.105/Cry2Ab2 resistance.The data generated should aid in modeling multiple-protein Bt resistance in H.zea.

金属氧化物纳米颗粒对磷的吸附及回收潜力

比较4种金属氧化物纳米颗粒(nMgO,nAl_2O_3,nTiO2和nFe_2O_3)对水体P的吸附性能,并探讨了pH、吸附时间、共存离子等因素对nMgO吸附P的影响,用XRD和XPS分析了nMgO对P的吸附机制,最后通过小青菜盆栽实验法探讨nMgO从养殖废水中吸附回收P的应用潜力.结果发现,在pH3.0~8.0范围内,nMgO对P的吸附量显著高于nAl_2O_3、nTiO_2和nFe_2O_3,4种纳米颗粒对P的吸附量分别可达40、31.77、15.93和13.08mg/g.吸附后P的解吸可逆性较差.nMgO对P的吸附能在0.5h内达到吸附平衡,P的吸附符合准二级动力学过程.体系共存的等量F^-、Cl^-、NO_3^-、SO_4^(2-)、Na^+、K^+和NH_4^+离子对nMgO吸附P无显著影响,Mg^(2+)和Ca^(2+)离子对P吸附具有促进作用.nMgO对P的吸附等温线可用Langmuir模型描述,最大吸附量达139.3mg/g.XRD和XPS分析表明,nMgO对P的吸附是伴有静电吸引的以表面络合沉淀反应为主的吸附过程.nMgO能有效地从养殖废水中吸附回收P,吸附P的nMgO作为肥料,能使小青菜干物质量从0.31g/kg土增加到0.96g/kg土.

植物纳米纤维薄膜研究进展

植物纳米纤维具有良好的力学及光学性能、精细的纳米结构、优异的生物相容性,可用于制备层状多孔的纳米纤维薄膜。文章概述了植物纳米纤维的制备、成膜的主要方法及其原理,详细介绍了植物纳米纤维薄膜优异的力学、光学及阻隔等性能及其在包装材料、防伪印刷、生物医药、储能材料和柔性显示器件等领域的应用研究进展,并对其未来应用前景进行了展望。

2000～2001年粤东柘林湾营养盐分布

2 0 0 0年 5月～ 2 0 0 1年 5月对粤东大规模增养殖区柘林湾及湾外附近海域进行了大量营养盐、浮游生物和一般理化因子的周年调查。结果表明 ,调查海域溶解性无机氮、磷、硅含量都明显偏高 ,年平均值分别达到 2 2 .64、1 .95和5 9.7μmol/ L。其中 ,氮、磷含量均超过国家三类海水的水质标准。由于湾顶黄冈河和湾周边排污排废的影响 ,营养盐的分布基本表现为由湾内向湾外 ,近岸向离岸递减的格局。大规模增养殖业造成的 2次污染对该湾营养盐的时空分布具有重要的影响。柘林湾氮、磷、硅含量虽全面偏高 ,但如以 Justic和 Dortch等的标准来衡量 ,该湾浮游植物生长受控于单一营养盐限制因子的出现率为氮 41 .75 % ,磷 2 2 .9% ,硅 2 .3 6%。

Natural Colonization of Rice by Arbuscular Mycorrhizal Fungi in Different Production Areas

Interactions between plants and soil microorganisms can influence the other interactions in which plants participate, including interactions with herbivores. Many fungi, including arbuscular mycorrhizal fungi(AMF), form symbiotic relationships with the roots they inhabit, and potentially alter defense against pests. The objective of this study was to document the extent of root colonization by AMF on non-flooded rice plants grown under conditions typical of commercial fields. We hypothesized that AMF naturally colonized rice plants in different rice producing field locations. Rice plant samples were collected from areas across the southern United States, including Texas, Mississippi, Arkansas and two research stations in Louisiana. We quantified the amount of AMF colonization in insecticide-free rice plants over three consecutive years(2014–2016). The results revealed natural colonization of AMF in all rice producing areas. In all the three years of survey, rice-AMF associations were the greatest in Arkansas followed by Mississippi and Texas. This research will help draw attention to natural colonization of AMF in rice producing areas that can impact future rice research and production by facilitating agricultural exploitation of the symbiosis.

Taxonomic composition, abundance and biomass of mesozooplankton in the Zhelin Bay—an estuary with intensive aquaculture

The Zhelin Bay is an estuary that supports intensive aquaculture in South China. Aside from traditional nutrient inputs derived from waste water and agriculture, the increased intensification of aquaculture has accelerated eutrophication during the past deeade, jeopardizing aquacultural production. Annual variations of mesozooplankton in the Zhelin Bay were described, providing baseline data for long-term ecological studies. The taxonomic composition, abundance and biomass of mesozooplankton were stud- ied monthly from July 2001 to July 2002 at 19 stations. Collections yielded 73 taxa, including 60 species of eopopods, three species of cladocerans, as well as tunieates, ehaetognaths, polyehaetes, medusae, ostraceds, rotatori, amphipods, planktonic mollusks, pelagic larvae, and planktonic shrimps. The Zhelin Bay was dominated by small mesozooplankton, with 76% of the species smaller than 1.4 mm, and 97% of the individuals smaller than 1.0 nun. Dominant species （ Paracalanus crassirostris, Oithona brevicornis, and Penilia avirostria） accounting for 60% of the total abundance were less than 0.6 mm in body length. Species diversity, biomass, and total abundance of mesozooplankton were greater in the samples collected outside the bay than inside the bay. Samples from the outer and eastern boundaries of the bay had greater biomass, diversity, and abundance than those from the inner and western boundaries. Total abundance and biomass had a unimodal annual pattern and were the greatest in August 2001 when water temperature was maximum, and the least in February 2002 when water temperature was minimum. Canonical correspondence analysis （CCA） revealed that temperature, turbidity, nutrients and salinity were the main determinants of spatial and temporal distributions of mesozooplankton in the Zhelin Bay, and six distinct zones were identified across the 19 sampling stations.

甘蔗提取物的抗氧化性能(英文)

膳食中的抗氧化剂有助于保护人体组织和细胞免受自由基的危害.目前,已有多种天然提取物制剂被用作膳食补充剂.文中比较了美国零售市场中4种甘蔗制品和1种玉米浆制品的组成和抗氧化能力,发现5种制品的抗氧化能力均与颜色密切相关.通过分析经不同澄清工艺并经真空浓缩的两种甘蔗汁的抗氧化能力,发现石灰澄清和纯碱澄清均不会造成抗氧化能力的显著降低.文中还对不同方法脱色后制品的抗氧化能力进行了比较.

Linking individual-tree and whole-stand models for forest growth and yield prediction

Background： Different types of growth and yield models provide essential information for making informed decisions on how to manage forests. Whole-stand models often provide well-behaved outputs at the stand level, but lack information on stand structures. Detailed information from individual-tree models and size-class models typically suffers from accumulation of errors. The disaggregation method, in assuming that predictions from a whole-stand model are reliable, partitions these outputs to individual trees. On the other hand, the combination method seeks to improve stand-level predictions from both whole-stand and individual-tree models by combining them. Methods： Data from 100 plots randomly selected from the Southwicte Seed Source Study of Ioblolly pine （Pinus taedo L） were used to evaluate the unadjusted individual-tree model against the disaggregation and combination methods. Results： Compared to the whole-stand model, the combination method did not show improvements in predicting stand attributes in this study. The combination method also did not perform as well as the disaggregation method in tree-level predictions. The disaggregation method provided the best predictions of tree- and stand-level survival and growth. Conclusions： The disaggregation approach provides a link between individual-tree models and whole-stand models, and should be considered as a better alternative to the unadjusted tree model.

Influence of Nano-Spray Dried Sodium Chloride on the Physicochemical Characteristics of Surface-Salted Cheese Crackers

Particle size reduction of salt to submicron range increases its surface area resulting in increased saltiness perception. The objective was to evaluate the incorporation of nano-spray dried sodium chloride on the physicochemical characteristics of surface-salted cheese crackers. The sodium chloride solution (3% w/w) was sprayed through a 4-μm nozzle with 125 L/min air flow, 38 kPa pressure, 95°C head temperature, and 90% spray to form the smallest submicrosalt particles. The cheese cracker treatments consisted of 3 different salt sizes (regular, microsalt and nano-spray dried salt) and 3 different concentrations (2%, 1.5% and 1%). The 9 (3 sizes × 3 concentrations) cheese cracker treatments were tested for salt concentration and sodium content at week 1. Water activity (aw), texture-fracturability, and color were determined at week 1 and 4 months of storage. The aw) and the L*, b*, C* and h* values in all treatments increased from 1 week to 4 months. The use of nano-spray dried salt on surface-salted cheese crackers allowed for a reduction of 25% - 50% of salt content without affecting the physicochemical attributes.

Optimization for microwave-assisted direct liquefaction of bamboo residue in glycerol/methanol mixtures

Bamboo residues were liquefied in a mixture of glycerol and methanol in the presence of sulfuric acid using microwave energy. We investigated the effects of liquefaction conditions, including glycerol/methanol ratio, liquefaction temperature, and reaction time on the conversion yield. The optimal liquefaction conditions were under the temperature of 120 °C, the reaction time of 7 min, the glycerol–methanol–bamboo ratio of 8/0/2（W/W）, and the microwave power of 300 W. Maximum conversion yield was 96.7 %. The liquid products were separated into two contents（water soluble part and precipitate part） by addition of a sufficient amount of water. By Fourier transform infrared（FT-IR）, the water soluble content mainly contained glycerol and its derivate and carbohydrate degradation products, and the precipitate content was mainly lignin derivatives.

Influence of Ethanol on Probiotic and Culture Bacteria <i>Lactobacillus bulgaricus</i>and <i>Streptococcus thermophilus</i>within a Therapeutic Product

Probiotic bacteria in plain yogurt namely of Lactobacillus ssp. have been reported to treat thrush, diarrhea, athlete’s foot, jock itch and vaginal yeast infections. Lactobacillus delbrueckii ssp. bulgarius (LB-12) and Streptococcus thermophilus (ST-M5) are lactic acid bacteria widely used in the manufacture of yogurt. Alcohol is used in manufacture of some medications such as cough syrups and some products such as eggnog and rum-raisin ice cream. The objectives were to study the effect of food grade ethanol on the growth of yogurt culture bacteria and the physico-chemical characteristics of therapeutic yogurt. The treatments were 0% (control), 2.5%, 5%, and 7.5% v/v ethanol in plain yogurt. The ethanol was incorporated by stirring it into one day old plain yogurt. Product characteristics were studied weekly for a month of refrigerated (4?C) storage. Data were analyzed using Proc Mixed model of Statistical Analysis System. The ethanol amount × storage period interaction effect was significant for Lactobacillus bulgaricus counts while the ethanol amount × storage period effect was not significant for Streptococcus thermophilus counts, viscosity, pH and titratable acidity (TA). Therapeutic yogurts with ethanol, at these concentrations, can successfully be manufactured without adversely influencing counts of its probiotic bacteria over product shelf life.

Nanocellulose-Based Biosensors: Design, Preparation, and Activity of Peptide-Linked Cotton Cellulose Nanocrystals Having Fluorimetric and Colorimetric Elastase Detection Sensitivity

Nanocrystalline cellulose is an amphiphilic, high surface area material that can be easily functionalized and is biocompatible and eco-friendly. It has been used singularly and in combination with other nanomaterials to optimize biosensor design. The attachment of peptides and proteins to nanocrystalline cellulose and their proven retention of activity provide a route to bioactive conjugates useful in designs for point of care biosensors. Elastase is a biomarker for a number of inflammatory diseases including chronic wounds, and its rapid sensitive detection with a facile approach to sensing is of interest. An increased interest in the use of elastase sensors for point of care diagnosis is resulting in a variety of approaches to elsastase sensors utilizing different detection technologies. Here elastase substrate peptide-celluose conjugates synthesized as colorimetric and fluorescent sensors on cotton cellulose nanocrystals are compared. The structure of the sensor peptide-nanocellulose crystals when modeled with computational crystal structure parameters demonstrates the spatio-stoichiometric features of the nanocrystalline surface that allows ligand to active site protease interacttion. An understanding of the structure/function relations of enzyme and conjugate substrate of the peptides covalently attached to nancellulose has implications for enhancing the biomolecular transducer. The potential applications of both fluorescent and colorimetric detection to markers like elastase using peptide cotton cellulose nanocrystals as a transducer surface to model point of care biosensors for protease detection are discussed.

Effect of Mild Sonication Conditions on the Attributes of <i>Lactobacillus delbrueckii</i>ssp. <i>bulgaricus</i>LB-12

Lactobacillus delbrueckii ssp. bulgaricus is a widely used bacterium for the production of some fermented dairy products. Mild sonication intensity condition is a non-destructive technique that uses sound waves to cause cavitation in aqueous solutions and may improve the permeability of membranes, speed up the transfer of substrates and promote cellular growth and propagation. The objective was to determine the effect of mild sonication intensities at different temperatures on growth, bile tolerance and protease activity of Lactobacillus delbrueckii ssp. bulgaricus LB-12. The treatments were four sonication intensities (8.07, 14.68, 19.83 and 23.55 W/cm2) randomized at three different temperatures (4℃, 22℃ and 40℃). The energy input (1500 J) was kept constant in all treatments. Control samples did not receive any sonication treatment. Growth and bile tolerance were determined every 2 h for 12 h of incubation. Protease activity was determined at 0, 12 and 24 h. Mild sonication conditions included 1) mild sonication intensities, 2) temperatures and 3) times, all three of which played a role in influencing the desirable attributes of Lactobacillus delbrueckii ssp. bulgaricus LB-12. Of all the mild sonication intensities studied, 14.68 W/cm2 had the best overall influence at certain time points forimproving the bile tolerance and growth at 4℃ and protease activity at 40℃. Mild sonication intensity of 23.55 W/cm2 had the best overall influence at certain time points for protease activity of at 22℃. Some mild sonication conditions could be recommended for improvement of some characteristics of Lactobacillus delbrueckii ssp. bulgaricus LB-12.

Effect of Flaxseed on Bile Tolerances of <i>Lactobacillus acidophilus, Lactobacillus bulgaricus</i>, and <i>Streptococcus thermophilus</i>

Consumption of flaxseed provides health benefits. Bile tolerance allows survival of probiotics in the intestinal tract. The objective was to determine whether or not flaxseed enhances bile tolerance of Lactobacillus acidophilus (L. acidophilus) LA-K, Lactobacillus delbruekii ssp. bulgaricus (L. bulgaricus) LB-12, and Streptococcus salivarius ssp. thermophilus (S. thermophilus) ST-M5. Control and experimental (62 g flaxseed/L) broths containing 0.3% oxgall were prepared for each culture, sterilized, cooled, inoculated, and plated for 8 h. Growth of each microorganism in both the control and experimental broths was evaluated by the slope of the regression line of its log count versus time after inoculation. Flaxseed significantly enhanced growth of L. acidophilus but not L. bulgaricus and S. thermophilus over 8 h compared to its corresponding control. Therefore, flaxseed improved the bile tolerance of L. acidophilus but not of S. thermophilus and L. bulgaricus.

Effect of Honey a Natural Sweetener with Several Medicinal Properties on the Attributes of a Frozen Dessert Containing the Probiotic <i>Lactobacillus acidophilus</i>

Lactobacillus acidophilus has several health advantages. Honey has several medicinal properties and is also a natural sweetener which could be used in frozen desserts. There are various types of honey based on color namely, light, amber and dark. Influence of honey on attributes of a probiotic frozen dessert is not known. The objective was to study the effect of light, amber colored and dark honey on the Lactobacillus acidophilus counts and quality attributes of probiotic ice cream. Ice creams were manufactured with use of Lactobacillus acidophilus at 50 g of frozen culture concentrate per 7.75 liters of ice cream mix and with the use of light or amber or dark honey individually. Control had no honey and was sweetened with sugar. Use of honey increased Lactobacillus acidophilus counts and viscosity, while decreased pH and melt down volume. Light honey ice cream had flavor and appearance scores comparable to the control vanilla ice cream. Light honey can be recommended for the manufacturing Lactobacillus acidophilus probiotic ice creams thus having a frozen dessert with the health advantageous medicinal properties of honey.

Almond Consumption Is Associated with Better Nutrient Intake, Nutrient Adequacy, and Diet Quality in Adults: National Health and Nutrition Examination Survey 2001-2010

Purpose: The purpose of this study was to examine the association between almond consumption, the most widely consumed tree nut in the US, and nutrient intake, nutrient adequacy, diet quality, and weight/adiposity in adults. Methods: Data from adults (N=24,808), 19+ years, participating in the NHANES 2001-2010 were used. The NCI method was used to estimate the usual intake of almonds and selected nutrients. Almond consumers were defined as those consuming any amount of almonds/almond butter. Percentages of the consumers/non-consumers below the Estimated Average Requirement (EAR) or above the Adequate Intake (AI) for select nutrients were determined. To assess significant differences for the percentage of almond consumers vs. non-consumers with intakes less than the EAR or above the AI, a Z-statistic for differences in population proportions was used. Covariate-controlled linear regression was used to determine differences in diet quality, measured by the Healthy Eating Index-2010 (HEI-2010), between the consumer groups. Body mass indices and waist circumference were assessed. P was set at p < 0.01. Results: Almond consumers were more likely to be non-Hispanic white, older, of higher income, more physically active, and were less likely to be a current smoker than non-consumers. Usual intake of almonds among consumers was 29.5 ± 1.5 g/day. Usual intake of protein;dietary fiber;vitamins A, D, E, and C;thiamin;niacin;riboflavin;folate, calcium, copper, magnesium, iron, phosphorus, selenium, zinc, and potassium was higher in almond consumers. Almond consumers were less likely to be below the EAR for protein, vitamins A, D, E, B12, and C;riboflavin;calcium;copper;magnesium;iron;phosphorus;and zinc. They were also more likely to be above the AI for dietary fiber and potassium. Total HEI-2010 scores were approximately 15 points higher in almond consumers. Body mass indices and waist circumference measures were lower in almond consumers. Conclusions: Moderate consumption of almonds should be encouraged as part of a healthy diet.

Yield and uptake of bahiagrass under flooded environment as affected by nitrogen fertilization

Bahiagrass (Paspalum notatum) is one of the most important forage grasses in subtropical region of USA and other tropical regions of the world. Although tolerant to short term flooding, bahiagrass is classified as a facultative upland (FACU+) species that suggest yield and plant persistence might be reduced under periods of extended waterlogging. The objective of this greenhouse study (2008-2009) was to determine the effect of nitrogen fertilization (0, 100, and 200 kg·N·ha–1) on yield (DMY), crude protein content (CPC), and nitrogen uptake (NUP) of bahiagrass under varying flooded conditions (0, 14, 28, 56, and 84 days). Results disclosed an overwhelming effect of N application on yield and uptake component of bahiagrass. Averaged across flooding duration, results showed that DMY (R2 = 0.91**), CPC (R2= 0.96**), and NUP (R2 = 0.99**) were linearly related to increasing levels of N fertilization. Plants without N fertilization that were submerged between 14 to 84 days had significantly lower amount of DMY when compared with plants that were fertilized with 100 or 200 kg·N·ha–1. Comparable DMY and NUP were obtained between plants fertilized with 200 kg·N·ha–1) at 0 day of flooding (11.7 ± 5.0 ton·ha–1) and plants fertilized with 200 kg·N·ha–1 at 84 days of flooding (9.8 ± 2.7 ton·ha–1). The practical implication of this study is that waterlogging may hamper yield and uptake while nitrogen fertilization could improve yield and uptake of bahiagrass under waterlogged condition.