Effects of different levels of energy and protein sources on the growth performance, feeding, survival rate and the chemical body composition of juvenile Pacific white shrimp (Litopenaeus vannamei)

The present study was carried out in order to establish an economical effective diet for the pacific white shrimp in the southern part conditions of Iran. With the consideration of three dietary energy levels (E1=262, E2=312, E3=362 kcal 100 g-1 diet) and six ratios of fish meal (FM) to soybean meal (SBM) [(P1=100%FM+0%SBM, P2=80%FM+20%SBM, P3=60%FM+40%SBM, P4=40%FM+60%SBM, P5=20%FM+80%SBM, P6=0%FM+100%SBM)], 18 experimental diets (with 36% crude protein) were prepared. Completely randomized design was used to assign 54 polyethylene 300 litre round tanks provided by aeration and flow through water system and was stocked by 19 juvenile as 3 replicates to each treatment. Shrimps average weight was about 0.77 grams at the start. After 56 days culture period, maximum growth and nutritional performances were observed in the P6E1 treatment (containing 100% soybean meal and 262 kcal 100 g-1 diet) and P5E1 treatment (containing 80% soybean meal and 262 kcal 100 g-1 diet). Also the highest survival rate of the shrimps was observed in the P1E1, P1E2, P3E3 and P5E3 treatments. Additionally interactive effect of different protein ratios and energy levels had significant difference on body protein, fat, fiber and ash contents (P<0.05). Results of the present study suggest the possibility replacement of at least 80% of dietary fish meal by soybean meal in the diet of pacific white shrimp in the conditions of southern part of Iran.

Studies on the restoration succession of PFU microbial communities in a pilot-scale microcosm

In order to imitate the restoration succession process of natural water ecosystem, a laboratory microcosm system of constant-flow-restoration was designed and established. A eutrophycation lake, Lake Donghu, was selected as the subject investigated. Six sampling stations were set on the lake, among which the water of station IV was natural clean water, and others were polluted with different degrees. Polyurethane foam unit microbial communities, which had colonized in the stations for a month, were collected from these stations and placed in their respective microcosms, using clean water of station IV to gradually replace the water of these microcosms. In this process, the healthy community in clean water continuously replaced the damaged communities in polluted water, the restoration succession of the damaged communities was characterized by weekly determination of several functional and structural community parameters, including species number (S), diversity index (DI), community pollution value (CPV), heterotrophy index (HI), and similarity coefficient. Cluster analysis based on similarity coefficient was used to compare the succession discrepancies of these microbial communities from different stations. The ecological succession of microbial communities during restoration was investigated by the variable patterns of these parameters, and based on which, the restoration standards of these polluted stations were suggested in an ecological sense. That was, while being restored, the water of station 0 (supereutrophycation) should be substituted with natural clean water by 95%; station I (eutrophycation), more than 90%; station II (eutrophycation), more than 85%; station III (eutrophycation), about 85%; station V (mesoetitrophycation), less than 50%. The effects of the structural and functional parameters in monitoring and assessing ecological restoration are analyzed and compared. (C) 2007 Elsevier Ltd. All rights reserved.

Primary succession of algal community structure in desert soil

The microbiotic crust study is among new focuses in investigating on the desertification control. Based on determination of algal crusts with different successive ages (4-, 8-, 17-, 34-, 42-year-old) and unconsolidated sand in the desert area, species composition and clustering analyses were carried out in this study. Results on successional orientation revealed that (1) the abundance of Cyanophyta, specially of Scytonema javanicum gradually decreased; (2) the abundance of Chlorophyta, Bacillariophyta and a species of Cyanophyta, Phormidium tenue increased; (3) the biodiversity increased gradually with the community succession; and (4) biomass of microalgae increased at the early stage, but decreased at the later stage due to the abundance of lichens and mosses. But, the speed of natural succession was so slow that the community-building species was still the first dominant species after 42 years, except that its dominant degree decreased just slightly. However, successive speed and trend were affected by water, vegetation coverage, terrain, time and soil physico-chemical properties as well, especially Mn content in the soil appeared to have a threshold effect.

Effect of acetylation on the properties of corn starch

Acetylated corn starches with different degrees of substitution (DS 0.85, DS 1.78, DS 2.89) were synthesized by the reaction of corn starch with acetic anhydride in the presence of acetic acid under varying reaction temperatures. The product was characterized by FTIR spectroscopy, H-1 NMR, X-ray diffraction and contact angle measurement. Acid-base titration and H-1 NMR methods were employed to determine the degree of substitution of product. FTIR spectroscopic analysis showed that the characteristic absorption intensities of esterified starch increased with increase in the degree of substitution, and the characterized peak of hydroxyl group almost disappeared in the spectrum of DS 2.89 acetylated starch. The detailed chemical microstructure of native starch and acetylated starch was confirmed by H-1 NMR, C-13 NMR and C-13-(1) H-1 COSY spectra.

Optimization of physical and optical properties of biodegradable edible films based on pea starch and guar gum

The influence of process variables (pea starch, guar gum and glycerol) on the viscosity (V), solubility (SOL), moisture content (MC), transparency (TR), Hunter parameters (L, a, and b), total color difference (ΔE), yellowness index (YI), and whiteness index (WI) of the pea starch based edible films was studied using three factors with three level Box–Behnken response surface design. The individual linear effect of pea starch, guar and glycerol was significant (p < 0.05) on all the responses. However, a value was only significantly (p < 0.05) affected by pea starch and guar gum in a positive and negative linear term, respectively. The effect of interaction of starch × glycerol was also significant (p < 0.05) on TR of edible films. Interaction between independent variables starch × guar gum had a significant impact on the b and YI values. The quadratic regression coefficient of pea starch showed a significant effect (p < 0.05) on V, MC, L, b, ΔE, YI, and WI; glycerol level on ΔE and WI; and guar gum on ΔE and SOL value. The results were analyzed by Pareto analysis of variance (ANOVA) and the second order polynomial models were developed from the experimental design with reliable and satisfactory fit with the corresponding experimental data and high coefficient of determination (R2) values (>0.93). Three-dimensional response surface plots were established to investigate the relationship between process variables and the responses. The optimized conditions with the goal of maximizing TR and minimizing SOL, YI and MC were 2.5 g pea starch, 25% glycerol and 0.3 g guar gum. Results revealed that pea starch/guar gum edible films with appropriate physical and optical characteristics can be effectively produced and successfully applied in the food packaging industry.

The legitimation of risk and democracy: A case study of Bt cotton in Andhra Pradesh, India

This thesis explores the inter-related attempts to secure the legitimation of risk and democracy with regard to Bt cotton, a genetically modified crop, in the state of Andhra Pradesh in India. The research included nine months of ethnographic fieldwork, extensive library and newspaper research, as well as university attendance in India, undertaken between June, 2010 and March, 2011. This comparative study (involving organic, NPM and Bt cotton cultivation) was conducted in three villages in Telangana, a region which was granted secession from Andhra Pradesh in July, 2013, and in Hyderabad, the state capital. Andhra Pradesh is renowned for its agrarian crisis and farmer suicides, as well as for the conflict which Bt cotton represents. This study adopts the categories of legitimation developed by Van Leeuwen (2007; 2008) in order to explore the theory of risk society (Beck, 1992; 1994; 1999; 2009), and the Habermasian (1996: 356-366) core-periphery model as means of theoretically analysing democratic legitimacy. The legitimation of risk and democracy in relation to Bt cotton refers to normative views on the way in which power should be exercised with regard to risk differentiation, construction and definition. The analysis finds that the more legitimate the exercise of power, the lower the exposure to risk as a concern for the collective. This also has consequences for the way in which resources are distributed, knowledge constructed, and democratic praxis institutionalised as a concern for social and epistemic justice. The thesis argues that the struggle to legitimate risk and democracy has implications not only for the constitution of the new state of Telangana and the region’s development, but also for the emergence of global society and the future development of humanity as a whole.

The succession of minima in the abundance of species

Many of the leading ecological and evolutionary characteristics of populations are governed by their effective population size, which in turn is strongly influenced by the minimum census size. The succession of minima of increasing rank R in time is described by the expected value of the next minimum ωR and by the expected time TR elapsing before it occurs. The relationships of ωR and TR with R together determine the minimal population expected to be encountered within a given period of time. These relationships depend on the dynamic model for species abundance. The four main types of model investigated here have characteristically different successions.

THE IMPACT OF BURNING AND GRAZING OF HEATHLAND PLANTS AND INVERTEBRATES IN COUNTRY ANTRIM

The impact of burning and grazing on plant, ground beetle and spider species was investigated experimentally in stands of varying ages (burnt in 1982 and 1988 and unburnt plots) on an area of heather moorland in County Antrim, north-east Ireland. Burning initiated complex succession pathways which appear to have characteristic plant and invertebrate species associations. Removal of Calluna dominance initiated a period of high plant species diversity. Investigation of initial post-fire regeneration suggested that the frequency of occurrence of plant species changed over time and was affected by grazing. Grouping of species by the position of their renewal bud, i.e. their life-form, did not account for all observed interspecific variation. The dominant species after burning were Eriophorum vaginatum, E. angustifolium and Vaccinium myrtillus. Studies of vegetation canopy structure showed that, even with the exclusion of the main grazing herbivores, Calluna will not re-establish itself as the dominant species until several years after burning. The ground beetle Nebria salina was trapped more often on plots burnt in 1988 than on unburnt plots or those burnt in 1982. In comparison, Pterostichus niger and Carabus granulatus were trapped in greater numbers on plots burnt in 1982 than on unburnt plots and plots burnt in 1988. The large species Carabus problematicus and Carabus glabratus were trapped in greater numbers on unburnt plots. Similarly, more of the spiders Ceratinella brevipes and Centromerita concinna were trapped on the plots burnt in 1982. In comparison, Lepthyphantes zimmermanni and Robertus lividus were trapped more often on unburnt plots than on plots burnt in 1982 and 1988. Results are discussed with respect to the importance of the continuation of traditional heathland management practices.

A biofuel strategy for Ireland with an emphasis on production of biomethane and minimization of land-take

Increasing energy consumption has exerted great pressure on natural resources; this has led to a move towards sustainable energy resources to improve security of supply and to reduce greenhouse gas emissions. However, the rush to the cure may have been made in haste. Biofuels in particular, have a bad press both in terms of competition with good agricultural land for food, and also in terms of the associated energy balance with the whole life cycle analysis of the biofuel system. The emphasis is now very much on sustainable biofuel production; biofuels from wastes and lignocellulosic material are now seen as good sustainable biofuels that affect significantly better greenhouse gas balances as compared with first generation biofuels. Ireland has a significant resource of organic waste that could be a potential source of energy through anaerobic digestion. Ireland has 8% of the cattle population of the EU with less than 1% of the human population; as a result 91% of agricultural land in Ireland is under grass. Residues such as slurries and slaughter waste together with energy crops such as grass have an excellent potential to produce biogas that may be upgraded to biomethane. This biomethane may be used as a natural gas substitute; bio-compressed natural gas may then be an avenue for a biofuel strategy. It is estimated that a maximum potential of 33% of natural gas may be substituted by 2020 with a practical obtainable level of 7.5% estimated. Together with biodiesel from residues the practical obtainable level of this strategy may effect greater than a 5% substitution by energy of transport. The residues considered in this strategy to produce biofuel (excluding grass) have the potential to save 93,000 ha of agricultural land (23% of Irish arable land) when compared to a rapeseed biodiesel strategy. © 2009 Elsevier Ltd. All rights reserved.

Rapid succession of plant associations on the small ocean island of Mauritius at the onset of the Holocene

The island of Mauritius offers the opportunity to study the poorly understood vegetation response to climate change on a small tropical oceanic island. A high-resolution pollen record from a 10 m long peat core from Kanaka Crater (560 m elevation, Mauritius, Indian Ocean) shows that vegetation shifted from a stable open wet forest Last Glacial state to a stable closed-stratified-tall-forest Holocene state. An ecological threshold was crossed at ∼11.5 cal ka BP, propelling the forest ecosystem into an unstable period lasting ∼4000 years. The shift between the two steady states involves a cascade of four abrupt (<150 years) forest transitions in which different tree species dominated the vegetation for a quasi-stable period of respectively ∼1900, ∼1100 and ∼900 years. We interpret the first forest transition as climate-driven, reflecting the response of a small low topography oceanic island where significant spatial biome migration is impossible. The three subsequent forest transitions are not evidently linked to climate events, and are suggested to be driven by internal forest dynamics. The cascade of four consecutive events of species turnover occurred at a remarkably fast rate compared to changes during the preceding and following periods, and might therefore be considered as a composite tipping point in the ecosystem. We hypothesize that wet gallery forest, spatially and temporally stabilized by the drainage system, served as a long lasting reservoir of biodiversity and facilitated a rapid exchange of species with the montane forests to allow for a rapid cascade of plant associations.

Primary assembly of soil communities: disentangling the effect of dispersal and local environment

It has long been recognised that dispersal abilities and environmental factors are important in shaping invertebrate communities, but their relative importance for primary soil community assembly has not yet been disentangled. By studying soil communities along chronosequences on four recently emerged nunataks (ice-free land in glacial areas) in Iceland, we replicated environmental conditions spatially at various geographical distances. This allowed us to determine the underlying factors of primary community assembly with the help of metacommunity theories that predict different levels of dispersal constraints and effects of the local environment. Comparing community assembly of the nunataks with that of non-isolated deglaciated areas indicated that isolation of a few kilometres did not affect the colonisation of the soil invertebrates. When accounting for effects of geographical distances, soil age and plant richness explained a significant part of the variance observed in the distribution of the oribatid mites and collembola communities, respectively. Furthermore, null model analyses revealed less co-occurrence than expected by chance and also convergence in the body size ratio of co-occurring oribatids, which is consistent with species sorting. Geographical distances influenced species composition, indicating that the community is also assembled by dispersal, e.g. mass effect. When all the results are linked together, they demonstrate that local environmental factors are important in structuring the soil community assembly, but are accompanied with effects of dispersal that may "override" the visible effect of the local environment.

Classification the geographical origin of corn distillers dried grains with solubles by near infrared reflectance spectroscopy combined with chemometrics: A feasibility study

In this study, 137 corn distillers dried grains with solubles (DDGS) samples from a range of different geographical origins (Jilin Province of China, Heilongjiang Province of China, USA and Europe) were collected and analysed. Different near infrared spectrometers combined with different chemometric packages were used in two independent laboratories to investigate the feasibility of classifying geographical origin of DDGS. Base on the same dataset, one laboratory developed a partial least square discriminant analysis model and another laboratory developed an orthogonal partial least square discriminant analysis model. Results showed that both models could perfectly classify DDGS samples from different geographical origins. These promising results encourage the development of larger scale efforts to produce datasets which can be used to differentiate the geographical origin of DDGS and such efforts are required to provide higher level food security measures on a global scale.

Electroanalytical determination of oxadiazon and characterization of its base-catalyzed ring-opening products

The electrochemical behavior of the hydrolysis products of oxadiazon was studied by cyclic and square-wave voltammetry using a glassy carbon electrode. Maximum currents were obtained at pH 12.8 in an aqueous electrolyte solution containing 30% ethanol and the current did not decrease with time showing that there was little adsorption of the reaction products on the electrode surface. The hydrolysis products of oxadiazon were identi®ed, after isolation and puri®cation, as 1-trimethylacetyl-2-(2,4-dichloro-5-isopropoxyphenyl)-2-ethoxycarbonylhydrazine (Oxa1) and 1-trimethylacetyl-2-(2,4-dichloro-5-isopropoxyphenyl) hydrazine (Oxa2) with redox potentials 0.6Vand 70.1V (vs. Ag=AgCl), respectively. Based on the electrochemical behavior of 1-trimethylacetyl-2-(2,4-dichloro-5-isopropoxyphenyl) hydrazine (Oxa2) a simple electroanalytical procedure was developed for the determination of oxadiazon in commercial products used in the treatment of rice crops in Portugal that contain oxadiazon as the active ingredient. The detection limit was 161074 M, the mean content and relative standard deviation obtained for seven samples of two different commercial products by the electrochemical method were 28.4 0.8% (Ronstar) and 1.9 0.2% (Ronstar GR), and the recoveries were 100.3 5.4% and 101.1 5.3 %, respectively.