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Arsenic Application Changed Growth, Photo-Synthetic Pigments and Antioxidant Enzymes Activity in Sorghum (Sorghum bicolor L.) Under Salinity Stress

Abstract

The elevation of arsenic (As) content in soils is of considerable concern with respect to its uptake by plant and subsequent entry into wildlife and human food chains. The treatment of sorghum seedlings with As as NaH2As4O. 7H2O at various concentrations (A1 = 0, A2 = 20, A3 = 40 and A4 = 60 mg As kg−1 soil) and salinity at four different levels (S1 = 0, S2 = 3, S3 = 6 and S3 = 9 dS m−1) reduced fresh and dry weights of sorghum plants. The co-application of As and salinity increased the guaiacol peroxidase (GPX) activity in shoot and root tissues. The highest GPX activity in shoot and root tissues was obtained at S2A4 and S3A3 treatments, respectively. The activity of catalase (CAT) in shoot was not changed, but unlike the GPX activity, salinity and As decreased the CAT activity in root tissues. Concerning the photosynthesis pigments, salinity had no effect on the chlorophyll ‘a’, chlorophyll ‘b’ and carotenoid content in leaves, but the As treatment significantly decreased the content of both chlorophyll types. Salinity increased the anthocyanin content in leaves. There were negative correlation between soluble carbohydrates (r2 = −0.78**) and stomata conductance (r2 = −0.45**) and dry weight of the plant biomass in this study. By increasing the salinity and As concentration in root medium, soluble carbohydrate in leaves increased but salinity decreased the leaf stomata conductance.

Open access
An assessment of the local empowerment and environmental management programme (LEEMP) for poverty alleviation in Oyo State, Nigeria

Abstract

Efforts to liberate the populace, most especially rural communities, from the shackles of poverty, have been ongoing through several approaches since the independent era in Nigeria. The most recent is the Local Empowerment and Environmental Management Programme (LEEMP) which is tailored to undertake projects capable of alleviating poverty. This study assessed the LEEMP projects in Itesiwaju Local Government Area of Oyo State in Nigeria. Data collection methods were through a questionnaire survey and an interview. A random sampling technique was employed to sample 152 residents from the study population of 30,400 and the results were analysed using both descriptive and inferential statistics. A binary logistics regression was used to determine the influence of the LEEMP projects on the socio-economic status of residents. The findings revealed that: LEEMP projects were mostly the initiatives of both the community and LEEMP officials (72%); over 80% of the respondents observed that community involvement was mainly about land provision and the labour force, justifying over 70% active involvement of the community in the project execution and maintenance. Inferentially, the prediction model was able to classify 83% of the cases correctly, indicating that the predictors contribute significantly to prediction power of the logistic regression model (p<0.000). The Pseudo R-Square of Cox & Snell’s R-square (28%) and Nagelkerke’s R (42%) also show that the model was relevant in predicting the influence of the LEEMP projects on the residents’ socio-economic status. However, age (p=0.000), household size (p=0.019), average monthly income (p=0.033), and educational status (p=0.038) predictors best contributed to the model prediction. The study, however, recommended among others, that the LEEMP projects should be extended extensively within the country accompanied by an injection of adequate funding and a project monitoring mechanism for continuous functionality and sustainability.

Open access
Bacillus subtilis BS-2 and Peppermint Oil as Biocontrol Agents Against Botrytis cinerea

Abstract

The purpose of this study was to assess the activity of Bacillus subtilis BS-2 and peppermint oil against Botrytis cinerea. In this study parameters such as the age and the density of the bacterial culture and the incubation temperature were taken into consideration. Furthermore, the cellulolytic activity of the bacterium was determined. The effect of peppermint oil was evaluated at a concentration range of 0.5-4.0 %. The research was conducted with a dual culture plate method. The influence of B. subtilis BS-2 and peppermint oil on the growth of B. cinerea was evaluated based on the growth rate index. It was noted that the bacterial culture occurred at an initial density of OD 560 = 1.0, cultivated at 30 °C for 48 hours demonstrated the strongest antagonistic effect (57.07 % inhibition). Furthermore, it was observed that the highest cellulolytic activity occurred on the bacteria incubated for 48 hours at 37 °C. The effect of mint oil, at the lowest concentration of 0.5-1.0 %, was much weaker on bacterial activity (1.1-12.1 % inhibition). The highest concentration (4.0 %) of mint oil caused the maximum inhibition (31.9 %) of the mycelial growth. B. subtilis BS-2 may be environmental-friendly alternatives for protecting plants against B. cinerea

Open access
Biological Aspect of Bullet Tuna Auxis rochei (Risso, 1810) in the Makassar Strait, West Sulawesi, Indonesia

Abstract

The objectives of the present study were to determine the size distribution, growth pattern, feeding habit and stomach fullness index of bullet tuna Auxis rochei in the Makassar Strait, West Sulawesi. The research was conducted for six months between March and August 2017. Sampling collection was carried out using the handline technique. A total of 2160 fish were caught. Their total length ranged from 15.8 to 28.5 cm and weight ranged from 52.3 to 366.5 g. The total length of male fish ranged from 18.5 to 28.5 cm and weight ranged from 77.5 to 366.5 g. The total length of female fish ranged from 15.8 to 27.5 cm and weight ranged from 52.3 to 328.8 g. The growth pattern of bullet tuna for both male and female fish was classified into a positive allometry (b>3); the type of food found in the fish gut consisted of crustacean (12.50% to 25.64%), chepalopods (7.32 to 34.80%) and unidentified (47.69 to 64.51%), respectively. Nonetheless, the predominant food condition was not identified and in the gut there was generally no food present. The stomach fullness index ranged from 1.13% to 7.18%, ¾ (12.11 to 15.74%), ½ (12.27 to 23.14%) and empty (59.26 to 65.74%). The length size distribution of male bullet tuna was larger than the female with a positive allometric growth pattern. However, the growth pattern of male and female bullet tuna statistically showed no difference.

Open access
Changes in growth caused by climate change and other limiting factors in time affect the optimal equilibrium of close-to-nature forest management

Abstract

Historical radial increment data based on tree ring analyses from the close-to-nature experimental forest management unit Smolnícka Osada in Central Slovakia were used for retrospective modelling of changes in forest dynamics to estimate the sensitivity of management planning goals under climate change. Four example years representing historical periods with typically different species-specific patterns of radial increment in mixed beech-fir-spruce forest (1910, 1950, 1980, and 2014) served as virtual starting points for the modelling. An advanced density-dependent matrix transition model was utilised for modelling stand dynamics. An integrated tool for nonlinear financial optimisation searched for an optimal management equilibrium. In addition to transition probabilities adjusted from increment data, some assumptions for changes in ingrowth and mortality related to the increment, as well as a case study concerning the reduced ingrowth changed by game browsing intensity, were tested for modelling more realistic historical ecological conditions. The sensitivity study revealed changes in the optimal management equilibrium represented by optimal basal area, tree species composition, diameter distribution and target harvest diameter over time due to the adapted ecological modelling. The main lesson of the past for the future is to avoid placing too much trust in the simple extrapolation of current trends, such as the observed continual decline in spruce related to climate change, but to be aware of temporal and possibly reversible processes, such as the observed extensive fir recovery after the reduction of air pollution. Tree species diversity appears to be the best option for the uncertain future.

Open access
Characterisation of Municipal Sewage Sludge as a Soil Improver and a Fertilizer Product

Abstract

In this study, we have determined the main important physical and chemical properties of municipal sewage sludge and compared them to the requirements of the Finnish Fertilizer Product Act and Fertilizer Product Decree in order to assess the potential utilization of this by-product as a fertilizer. Except for Hg (1.4 mg/kg d.m.), the total concentrations of Cd, Cu, Ni, Pb, Zn, Cr and As in our sewage sludge were lower that the Finnish maximum permissible heavy metal concentrations for sewage sludge used as a fertilizer products. However, the sewage sludge may be utilized as a soil improver, a growing media or as a fertilizer product in landfill sites (e.g. surface structures) or in other closed industrial areas, because the above mentioned Finnish limit values are not applied at these sites. If the sewage sludge is to be utilized in these kinds of areas, an environmental permit may be needed. According to BCR-extraction, the lowest release potential (solubility) from the sample matrix was observed for sulphur (58.4 %) and the highest for Cd (100 %).

Open access
Comparative Review of Artificial Light Sources for Solar-Thermal Biomass Conversion Research Applications

Abstract

In recent years solar-thermal methods of waste biomass conversion are promptly gaining on attention. For researchers working in areas that suffer from lack of natural solar power, the choice of proper solar simulator for the study is crucial. Solar simulator consist of artificial light source enclosed in proper housing with optical and cooling system, powered by dedicated power supply. Solar simulators are not only granting independence from external conditions, yet provide possibility of research expand due to tuneable output power and emissive spectrum. Over the years, solar simulators were powered by different types of lamps. Throughout the history, the solar simulators were used mainly in photovoltaic and space research, crystal growth industry, and the material testing. For mentioned purposes, the total thermal output power of simulator was playing secondary role in comparison to urgent need of spectral match, irradiance distribution and beam uniformity with terrestrial or extra-terrestrial sunlight. For thermal applications, solar simulators are facing the challenge of providing high output power, described by high radiant heat flux and high heat flux density over the specified target area. In presented paper the comparison of xenon arc, metal halide lams and tungsten halogen for thermal applications has been presented with emphasis on available thermal power, spectral match with natural sunlight and operational issues. The course of decision taken during the selection of artificial light source for construction of laboratory-scale solar pyrolytic reactor is proposed.

Open access
A Comparison of ETV and LA for the Determination of Trace Elements in Solid Samples by MIP OES

Abstract

The performance of electrothermal vaporization (ETV) and laser ablation (LA) of dry aerosols as sample introduction systems for microwave induced plasma optical emission spectrometry (MIP OES) are compared and evaluated in terms of detection limits, precision and accuracy for the determination of trace elements (Ca, Cd, Cu, Fe, Mg, Mn, Sr, Zn) in the same solid micro samples. In MIP OES both radiation sources can be independently adjusted to optimize the sampling process and then its subsequent excitation. A univariate approach and simplex optimization procedure were used to obtain the best signal/noise (S/N) ratio and derive analytical figures of merit. A comparison using a Student’s t-test between the results obtained by both ETV/LA-MIP OES methods for trace elements, and concentrations in standard reference material (SRM) and certified reference materials (CRMs) showed that there was no significant differences on a 95 % confidence level. The detection limits of the tested elements in solid samples by ETV/LA-MIP OES were in the range of 0.1 to 11 µg g−1 for all elements determined, while the corresponding absolute values in the range of ng. The precision of the results for ETV-MIP OES and LA-MIP OES varied between 2 and 4 % and 3 and 7 %, respectively. The linear dynamic ranges in the ETV/LA-MIP OES are extend over three decades of concentration. The methods were validated by the analysis of NIST SRM 2711Montana Soil, NRCC CRM PACS-2 Marine Sediment and NRCC CRM TORT-2 Lobster Hepatopancreas of different matrix composition and by the standard addition technique.

Open access
Competitiveness of the Czech Meat Industry on the Single Market

Abstract

New Member States have been part of the Single market since joining the European Union in 2004. This step brought various challenges in each of these countries because of appreciable difference in competitiveness compared to old EU Member States. This article puts to the test the competitiveness of the Czech meat industry. This is one of the most important parts of the agri-food production, which is still a very important part of regional economics in less developed regions. Thus, it represents cultural heritage of the countryside. The main aim is to investigate specific branches of the Czech meat industry according to their competitiveness on the Single market. In the article, we make conclusion on different states of the competitiveness of three main branches of the Czech meat industry, which represents 85.6% of the overall meat export. Conducted research provided information on positive change in the export during the observed period of time, but the comparison of absolute export and import numbers did not refer to a positive development of the Czech meat industry. Furthermore, we observed tendency to locate meat production near local markets and in developed regions.

Open access
Cross-Border Comparison of Non-Forest Woody Vegetation in the White Carpathians (Central Europe) Over Last 65 Years

Abstract

Landscape structure is determined by human activities and natural processes. Despite both influences are described in many studies, there remains still question, how the landscape structure reflects the individual socio-economic predictors. To answer this question we compared landscape structure, with emphasis on non-forest woody vegetation, of two states, however, with common socio-economic and political history. Non-forest woody vegetation represents characteristic feature in rural landscape, which increases water retention, biodiversity and bio-migration using green structures. In our study we supposed, that non-forest woody vegetation will have high sensitivity to societal changes and nature conservation measures. On an example of border region in former Czechoslovakia we compared three classes of non-forest woody vegetation (solitaires, patches and linear elements) in three time horizons (1950, 1986, 2011). The most significant differences in spatial structure of non-forest woody vegetation between countries were in the number and area of solitaires, which decreased during the entire period. However, the largest solitaire decrease was in 1950-1986, mainly in correspondence with socialist collective farming. Moreover, the decrease was higher in the Slovak part compared to the Czech part. The primary reason for this was the removal of non-forest woody vegetation on one side and the joining crowns into bigger patches on the other side. The current trend of increasing area of patch and linear elements is related to natural succession. We assume that the main drivers of different development in non-forest woody vegetation in the border region after the split of Czechoslovakia were different management measures applied in nature and landscape conservation and social development.

Open access