Effect of calcium against salinity-induced inhibition in growth, ion accumulation and proline contents in Cichorium intybus L

This study assesses the effect of NaCl (80 and 160 mM) and CaCl2 (10 mM) solutions, alone and in combination, to 30-day-old seedlings of Cichorium intybus L. Observations were made at 30 day intervals from the time of treatment till harvest (180 days after sowing). Application of NaCI resulted in significant decreases in lengths of root and stem, in dry weights of root, stem and leaves and in the leaf area, as compared with control. The reduction was less with the combined application of NaCI and CaCI2 than with the NaCI treatment alone. On the contrary treatment of CaCl2, alone promoted the above variables. Proline content in the leaves was enhanced with NaCl and CaCI, alone as well as with the NaCI + CaCI2 treatments; the maximum (six-fold) enhancement was observed with the combined treatments, compared with NaCl (four-fold increase) and CaCl2 (two-fold increase) alone. The sodium (Na+) and Chloride (CI) contents in different plant parts increased both with NaCI and with NaCI+ CaCI2 treatments. The maximum accumulation was observed in leaves, followed by that in stem and root. The potassium (K+) and calcium (Ca2+) contents decreased under NaCl stress, but increased with CaCI2 treatment. Thus, calcium ameliorated the deleterious effects of NaCI stress and stimulated the plant metabolism and growth.     

Preparation and investigation of poly(methylmethacrylate) nano-capsules containing haloxyfop-R-methyl and their release behavior

Abstract

In this study, the preparation and characterization of haloxyfop-R-methyl herbicide loaded in poly(methylmethacrylate) (PMMA) nano-capsules by emulsion polymerization and its release behavior were investigated. The chemical characterizations of PMMA/haloxyfop-R-methyl nano-capsules were confirmed by FT-IR spectroscopy method, and the surface morphology was studied by field emission scanning electron microscopy and transmission electron microscopy. Also, the herbicide loading and encapsulation efficiency were analyzed for the herbicide-loaded nano-capsules. The release rate of PMMA/haloxyfop-R-methyl nano-capsules was determined by UV-visible spectroscopy. The thermal properties and thermal stability of nano-capsules were explored by the thermal gravimetric analysis method. The diameter of the nano-capsules was in the range of 100–300?nm. Increasing the amount of herbicide in nano-formulations significantly affected the surface of the nano-capsules and reduced their surface smoothness. Triton-X100 was identified as the best surfactant for the preparation of nano-capsules, and the sample containing the lowest herbicide content showed the best performance in terms of encapsulation and loading efficiency. This sample showed a steady-state release rate during the six days.     

Earthworm additions affect leachate production and nitrogen losses in typical midwestern agroecosystems

Earthworms affect soil structure and the movement of agrochemicals. Yet, there have been few field-scale studies that quantify the effect of earthworms on dissolved nitrogen fluxes in agroecosystems. We investigated the influence of semi-annual earthworm additions on leachate production and quality in different row crop agroecosystems. Chisel-till corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] rotation (CT) and ridge-till corn-soybean-wheat (Triticum aestivum L.) rotation (RT) plots were arranged in a complete randomized block design (n = 3) with earthworm treatments (addition and ambient) as subplots where zero-tension lysimeters were placed 45 cm below ground. We assessed earthworm populations semi-annually and collected leachate biweekly over a three-year period and determined leachate volume and concentrations of total inorganic nitrogen (TIN) and dissolved organic nitrogen (DON). Abundance of deep-burrowing earthworms was increased in addition treatments over ambient and for both agroecosystems. Leachate loss was similar among agroecosystems, but earthworm additions increased leachate production in the range of 4.5 to 45.2% above ambient in CT cropping. Although leachate TIN and DON concentrations were generally similar between agroecosystems or earthworm treatments, transport of TIN was significantly increased in addition treatments over ambient in CT cropping due to increased leachate volume. Losses of total nitrogen in leachate loadings were up to approximately 10% of agroecosystem N inputs. The coincidence of (i) soluble N production and availability and (ii) preferential leaching pathways formed by deep-burrowing earthworms thereby increased N losses from the CT agroecosystem at the 45-cm depth. Processing of N compounds and transport in soil water from RT cropping were more affected by management phase and largely independent of earthworm activity.     

韩国绿色种养循环农业发展概况与经验启示

联合国将碳中和视为当今世界最为紧迫的任务,而农业是温室气体排放最多的产业之一,各国相继出台政策积极开展农业农村减排工作。韩国自2012年开始逐渐减少海洋粪污排泄量,并大力实行绿色种养循环农业,解决本国内畜禽粪污问题。韩国作为中国的重要海上邻国,不论是从研究借鉴角度抑或生态系统共享角度,了解其环境保护政策都是十分必要的。本文从韩国实施的主要政策、各地区农地养分收支现状、代表性运营模式案例、政策关注焦点等方面介绍韩国绿色种养循环农业的发展概况,结合中国绿色种养循环农业现状开展研究。提出三点政策建议：第一,进一步完善畜禽粪污资源化利用机具补贴辅助管理系统,提高系统在农户中的普及率;第二,提高全民环保意识的同时,政府的角色不应局限自上而下的引导型,应该积极促进种植户和养殖户间的自发组织,并大力提倡吸纳社会资本,集结社会各方力量;第三,促进绿色种养循环农业产品的商品化和品牌化,从而调动农户参与绿色种养循环农业的积极性。     

Adsorption of Crystal Violet Dye from Aqueous Solution by Poly(Acrylamide-<Emphasis Type="Italic">co</Emphasis>-Maleic Acid)/Montmorillonite Nanocomposite

Poly(acrylamide-co-maleic acid)/montmorillonite nanocomposites, were synthesized via in situ polymerization with different maleic acid and MMT content. The capability of the hydrogel for adsorption of crystal violet (CV) was investigated in aqueous solutions at different pH values and temperatures. The pseudo-second-order kinetics model could fit successfully the adsorption kinetic data. The effects of maleic acid to acrylamide molar ratio (MA_R), weight percent of MMT (MMT%), the pH of medium and the solution temperature (T) on the CV adsorption capacity (q _e ) of adsorbents were studied by Taguchi experimental design approach. The results indicated that increasing the MMT% leads to a greater q _e . The q _e value of adsorbents increased also with increasing both MA_R and pH, while reduced when the temperature of medium increased. The relatively optimum conditions to achieve a maximum CV adsorption capacity for P(AAm/MA)/MMT adsorbents were found as: 0.06 for MA_R and 5 % of MMT%, medium pH = 7 and T = 20 °C.     

EFFECTS OF CONTEXT ON EVERYDAY CONVERSATIONS OF TURKISH UNIVERSITY STUDENTS

This study employed a diary method to investigate everyday conversations. Consistent with a dynamic view of partner context interaction, it was predicted that conversations occurring in different contexts would show variations with respect to topics and conversation partners. Turkish university students recorded durations, topics, and conversation partners of their conversations for seven consecutive days. Contexts, topics, and partners were categorized. Respondents were utilized as units of analyses. Analyses revealed that context of conversations were related to topic and partner categories as well as intimacy ratings of partners and topics.     

Can oligopsony power be measured? The case of U.S. old newspapers market

This paper uses an index analogous to Lerner-index in the input market to derive a price–cost margin that measures input exploitation by few large buyers. This paper identifies oligopsony characteristics associated with the old newspaper (ONP) input market for recycled-content newsprint manufacture and then examines the impacts of market performances on ONP input prices. The wastepaper recycling market, in particular, ONP has not been successful in utilizing the ONP generated. The existence of high sunk costs for entry to the market, along with the small numbers of buyers in the old newspapers market, were the reasons to believe that the waste paper industry had oligopsony elements among paper recycling mills. The regional oligopsony/oligopoly indices were derived and the impact of these market powers on ONP input prices were examined for period 1972–1995. The findings of this study were: oligopsony elements were present to certain degrees among the recycled-content newsprint manufacturers; and the oligopsony market power enabled these mills to exert a larger price–cost margin on ONP input market.     

Epidemiological and biomechanical evaluation of airline baggage handling

Objectives. Musculoskeletal disorders (MSDs) are prevalent among airline baggage handlers due to manual materials handling. In this study, the Nordic musculoskeletal questionnaire (NMQ), the revised National Institute for Occupational Safety and Health (NIOSH) lifting equation, and the University of Michigan 3D Static Strength Prediction Program? (3DSSPP) were used to analyze MSDs among baggage handlers. Methods. The NMQ was filled out by 209 baggage handlers and 46 arbitrarily selected baggage handlers were evaluated using the NIOSH method and 3DSSPP. Results. The obtained results showed that the most common MSDs occurred in the lower back region. The next risky regions included knees, neck, and upper back, respectively. The NIOSH results confirmed that the subjects lifted loads heavier than the permitted limit and their lifting postures were inappropriate. The results of the 3DSSPP also indicated that compression forces exceeded the NIOSH limit in these awkward postures. Conclusions. Relying on this study, holding compulsory ergonomic lifting training courses could be proposed for workers and regulations adjusting an upper limit for maximum baggage weight must be also enacted in order to improve occupational health and prevent the prevalence of increasing MSDs.     

Modified Sugarcane Bagasse with Tartaric Acid for Removal of Diazonium Blue from Aqueous Solutions

The present study concerns with exploring the possibility of using of tartaric acid pretreated sugarcane bagasse (SCB) for removing diazonium blue (DB) from aqueous solutions. The effect of different factors on the efficiency of the adsorbent for the DB dye removal was investigated, including initial dye concentration, contact time, SCB dosage and SCB particle size. Langmuir, Freundlich, Tempkin and D–R isothermal models have been employed to analyze the adsorption equilibrium data. It was found that the adsorption of the dye fits well with the D–R model. The adsorption kinetics was also done applying four kinetic models. The regression equation coefficients refer to fitting the data to the second-order kinetic equation for removal of the DB dye. It is probable that the rate limiting step is a chemical adsorption between the adsorbent and the dye. This chemisorption process is further confirmed from the energy value of 15.1 kJ mol^?1 deduced from the D–R isotherm.     

New Methods for the Preparation Nanosized Metal Coordination Polymers

Transition-metal coordination polymers [M(ndc)(bpy)·(H₂O)m]·xH₂O (where M = Co(II), Ni(II), Cu(II) and Zn(II), ndc = 1,4-naphthalenedicarboxylate, bpy = 4,4′-bipyridine; m = 0 or 1; x = 1 or 2) were prepared by reacting the ligands and metal ions at room temperature with the aid of microwave irradiation and sonication methods. The structure of the coordination polymers was assigned based on elemental analysis, FT-IR and electronic spectral studies, thermal analysis, scanning electron microscope and X-ray powder diffraction. Thermogravimetric analysis was also used to follow up the possible thermal decomposition steps and to calculate the thermodynamic parameters of the nano-sized metal complexes. The kinetic parameters were calculated making use of the Coats–Redfern and Horowitz–Metzger equations. All obtained results of the different technics used in our study stated the ability to synthesis the metal coordination polymers of our interest using both microwave irradiation and sonication methods.