Evaluation of industrial waste black cumin (Nigella Sativa) for biohydrogen production without pretreatment

Environment, Development and Sustainability - The depletion of fossil fuels and the fact that fossil fuels pollute the environment accelerated the trend toward environmentally friendly energy...     

Modeling individual tree mortality for crimean pine plantations

Individual tree mortality model was developed for crimean pine (Pinus nigra subsp. pallasiana) plantations in Turkey. Data came from 5 year remeasurements of the permanent sample plots. The data comprises of 115 sample plots with 5029 individual trees. Parameters of the logistic equation were estimated using weighted nonlinear regression analysis. Approximately 80% of the observations were used for model development and 20% for validation. The explicatory variables in the model were ratio of diameter of the subject tree and basal area mean diameter of the sample plot as measure of competition index for individual trees, basal area and site index. All parameter estimates were found highly significant (p < 0.001) in predicting mortality model. Chi-square statistics indicate that the most important variable is d / d(q), the second most important is site index, and the third most important predictor is stand basal area. Examination of graphs of observed vs. predicted mortality rates reveals that the mortality model is well behaved and match the observed mortality rates quite well. Although the phenomenon of mortality is a stochastic, rare and irregular event, the model fit was fairly good. The logistic mortality model passed a validation test on independent data not used in parameter estimation. The key ingredient for obtaining a good mortality model is a data set that is both large and representative of the population under study and the data satisfy both requirements. The mortality model presented in this paper is considered to have an appropriate level of reliability.     

Forecasting precious metal price movements using trader positions

In the early 2000s, the precious metal markets entered into a new phase where a steady rise of prices had been observed until the October 2008 crash. Given the size and importance of precious metal market, as well as the hedging capacity of precious metals due to their low correlation with equity markets (Draper et al., 2006), the question we want to arise is whether trader positions predict the direction of gold, platinum, and silver spot price movements. The forecasting content of the Commodity Futures Trading Commission’s Commitment of Traders report for platinum, silver and gold prices using trader positions is investigated in a VAR framework. Granger causality tests are conducted to determine whether a relation between trader positions and market prices exists. An examination of the extreme trader positions on price movements is also conducted. The results indicate that market return is a significant parameter in explaining trader’s positions for all trader types in each of the precious metal markets under consideration after the beginning of 2000s where we detect a structural break for each of the market under study. Commercial traders are found to be negative feedback traders, that is, they sell when the prices increase in the market. On the other hand, in line with the previous literature, a positive correlation between returns and positions held by non-commercial and non-reporting traders is found. However, trader’s net positions do not lead market returns in general. There is some evidence on the forecasting ability of extreme trader positions on market returns.     

Screening of δ-aminolevulinic acid dehydratase from Pseudomonas strains as biosensor for lead and some other metals contamination

δ-Aminolevulinic acid dehydratase (ALAD; E.C. 4.2.1.24) is a metalloprotein and plays a crucial role in heme synthesis. Its sensitivity to toxic metals depends on the metallic co-factors. In this study the effects of some heavy metals on ALADs activity of five Pseudomonas isolates from Akar?ay stream (Afyonkarahisar) have been studied in order to determine whether their ALADs could be used as biosensor for lead and other heavy metals contamination. The data obtained from the study were analysed statistically by using SPSS 10.0 software for Windows. According to the results, Ni(II) increased the ALAD activity of Pseudomonas putida, Pseudomonas pseudoalcaligenes and Pseudomonas aureginosa ATTC 27853. Mn(II) also increased the enzymic activity in all strains examined except P. pseudoalcaligenes. These were found not to be statistically meaningful. P. aeruginosa 2’s enzymic activity was inhibited by Mg(II) and Zn(II), significantly (p’lt;’.05). There was a statistically meaningful relation between enzymic activity of both P. pseudoalcaligenes, P. putida and increasing Pb(II) concentration (p’lt;’.05). In addition, a formula was also deviced in order to determine the doses of metals in the environment of the organisms. As a result of the study, we can suggest that Pseudomonas ALADs can be used as a biosensor for lead and some other heavy metal exposure in aquatic environments.     

Natural tree collectives of pure oriental spruce [Picea orientalis (L.) Link] on mountain forests in Turkey

Distribution area of oriental spruce [Picea orientalis (L.) Link.] in the world is only in the north-east of Turkey and Caucasian. Because of being the semi monopoly tree with respect to its distribution and representing the upper forest line, it is necessary to analyse, evaluate and model the stand structures of oriental spruce forests in Turkey. In this research, some sampling plots were selected in timberline and treeline in the subalpine forest zone in Turkey. In these sampling plots some information about occurrence and development of the tree collectives was obtained. A total of 12 sampling plots (6 in timberline and 6 of them in treeline) were studied and horizontal and vertical stand profiles were obtained, while number of trees ranges between 2-86 in the tree collectives in treeline and in timberline 3-12. According to this, area per tree in treeline and in timberline is determined as 1.02 m2 and 3.75 m2 on an average respectively. Mean age of trees to reach breast height is 43 years in treeline sampling plots and 22 years in timberline sampling plots. According to the ratio of h (mean height) / d1.30 (diameter at breast height), stand stability values were calculated and it was determined if the stands were stable on the basis of the sampling plots. Stability values of the sampling plots changed between 33 and 75.     

Characterization of soil erosion and its implication to forest management

Forests have traditionally been managed to maximize timber production or economic profit, completely neglecting other forest values. Nowadays, however, forests are being managed for multiple uses. The basic requirement of multiple use forestry is to identify and quantify forest values and to determine management objectives. The priorities of management objectives, however, must be decided. In this study, a model predicting the soil loss for multi objective forest management was developed. The model was based on data from remeasurement of permanent sample plots. The data were gathered from 132 sample plots. Approximately 80% of the observations were used for model development and 20% for validation. The model was designed for even aged and uneven aged forests, as well as for forests with mixed and pure species composition. The explicatory variables in the model were mean diameter and number of trees. All parameter estimates were found highly significant (p < 0.001) in predicting soil loss. The model fit and validation tests were fairly good. The soil loss model presented in this paper was considered to have an appropriate level of reliability. It can be used in the overall multi-objective forest management planning, but, it should be limited to the conditions for which the data were gathered.     

Applications of Bacteriophage Cocktails to Reduce Salmonella Contamination in Poultry Farms

Food and Environmental Virology - Salmonella contamination is a critical problem in poultry farms, with serious consequences for both animals and food products. The aim of this study is to...