Characterization of Ribulose-1,5-bisphosphate carboxylase-oxygenase activase (Rca) genes in durum wheat

Genetic Resources and Crop Evolution - Durum wheat (T. turgidum L. var. durum) is one of the most widely cultivated cereal crop in the Mediterranean area. Its production has been triggered by...     

Carcinogenicity of acrylamide: a computational study

This paper reports a series of ab initio, density functional theory (DFT), and semiempirical molecular orbital (MO) calculations concerning the reaction between the ultimate carcinogen of acrylamide and guanine. Acrylamide--a product of the Maillard reaction--is present in a variety of fried and oven-cooked food. After intake, it is epoxidized by cytochrome P450 2E1 to yield the ultimate carcinogen--glycidamide. Effects of solvation were considered using the Langevin dipoles (LD) model of Florian and Warshel and the solvent reaction field (SCRF) model of Tomasi and co-workers. In silico activation free energies are in very good agreement with the experimental value of 22.8 kcal/mol. This agreement presents strong evidence in favor of the validity of the proposed S N2 reaction mechanism and points to the applicability of quantum chemical methods to studies of reactions associated with carcinogenesis. In addition, insignificant stereoselectivity of the studied reaction was predicted. Finally, the competing reaction of glycidamide with adenine was simulated, and the experimentally observed regioselectivity was successfully reproduced.     

Fungistatic activity of bicyclo[4.3.0]-γ-lactones

Five optically active and sixteen racemic lactones (nine of them new) of bicyclo[4.3.0]nonane structure were synthesized. IC(50) values for the following phytopathogens were determined: Aspergillus ochraceus AM 456, Fusarium culmorum AM 282, Fusarium oxysporum AM 13, Fusarium tricinctum AM 16. Effect of compound structures, especially stereogenic centers, on fungistatic activity has been discussed. The highest fungistatic activity was observed for trans-7,8-dibromo-cis-3-oxabicyclo[4.3.0]nonan-2-one (3c), IC(50) = 30.1 μg/mL (0.10 μM/mL), and cis-7,8-epoxy-cis-3-oxabicyclo[4.3.0]nonan-2-one (3b), IC(50) = 72.2 μg/mL (0.47 μM/mL), toward F. oxysporum AM 13.     

TRAP molecular markers as a system for saturation of the genetic map of durum wheat

Target region amplification polymorphism (TRAP) is a relatively new PCR-based technique that detects large numbers of loci in a single reaction without extensive pre-PCR processing of samples. The aim of this study was to integrate TRAP markers in an EST-derived SSR linkage map of a RIL mapping population from the cross of the durum wheat cultivars Ciccio and Svevo, for a more general purpose of establishing a high-throughput system for genetic map saturation. Primer combinations producing PCR products with at least 4–5 polymorphic bands were selected and analyzed across the mapping population. The PCR reactions produced a total of 2,881 fragments with an average of 52 peaks per reaction. A total of 142 new TRAP markers were mapped and found to be randomly distributed in the genome. The total length of the map was 2,043.0 cM, with an average chromosome length of 145.9 cM. Homoeologous group one had the highest number of TRAP markers (38 loci) and the longest map length (407.9 cM) for a total of 87 markers, while the homoeologous group five had the lowest TRAP marker number (5 loci) and the shortest map length (232.5 cM). The distribution of markers among the seven homoeologous groups was random. The results indicate that TRAP is highly efficient in genetic mapping, generating a large number of markers scattered across the genome. This closes many existing gaps in marker coverage and may join otherwise separate linkage groups.     

Detection of cows with insemination problems using selected classification models

In the present study, the detection of cows with artificial insemination (AI) difficulties using selected statistical and machine learning methods is presented. Cows were divided into two classes: those that conceived after one or two services (“GOOD”) and those that required more than two services per conception (“POOR”). The best performance was exhibited by one of the artificial neural networks (ANN) and the multivariate adaptive regression spline (MARS) method (AIC, BIC, RMS and accuracy); whereas logistic regression (LR) and classification functions (CF) were of somewhat lower quality. The detection of cows with AI difficulties, performed on the basis of the test set comprising new instances, showed that the ANN and MARS were more precise in comparison with the statistical methods. Sensitivity and specificity were over 85% for the perceptron with two hidden layers (MLP2) and MARS and approximately 80% or lower for LR and CF. From among variables determining the AI category, the average calving interval and cow body condition index were the most important. Other significant variables were lactation number, pregnancy length, sex of calf from previous calving and cow age. The prognoses obtained using ANN and MARS can be used for the appropriate preparation of cows for AI.     

Evaluation of the Heterosis on Leaf Photosynthesis of Remote-Cross F1 Rice (Oryza saliva L.)

The heterosis of leaf photosynthesis was studied on the main characters included in the range from CO₂exchange rate (CER) to enzymatic activity using a remote cross F, rice. The CER was significantly higher than those of the parental strains, showing a 111 % heterosis effect on average; at the same time strong heterosis was observed for the leaf area production and growth. Also stomatal and mesophyll conductances increased in the F₁ rice, which may contribute to the increase in CER. Chlorophyll content (Ch1), soluble protein content (SPC) and ribulose 1,5-bisphosphate (RuBP) carboxylase activity (RCA) were measured as the internal factors related to photosynthesis, and compared between the F₁, rice and the parents. For all these factors, the F₁ rice showed low values compared to the parents. Positive heterosis was not expressed here. On the other hand, the specific activity of RCA (RCA/SPC) increased in the F₁, rice, showing a 120% heterosis effect. This may be regarded as one of the main causes for the increase in CER of the F₁, rice. High CER expressed as heterosis concurrently with large leaf area production is one of the important findings in our study, and this may suggest a high possibility of further improvement in biomass production or yield of rice by gathering the advantageous elements into a hybrid plant.     

Towards More Efficient Incentives for Agri‐environment Measures in Degraded and Eroded Vineyards

Evaluating the economic damage caused by soil erosion is important. In addition to increasing the awareness of the problem among farmers and policy makers, evaluation of the economic damage caused by erosion can promote the implementation of more sustainable soil management practices. In the present study, we describe a new approach to evaluate incentives for the adoption of agri‐environment measure (AEM) in degraded and eroded vineyards. To estimate this incentive, the replacement cost (RC) and the loss of income are calculated when the vineyard is managed with conventional tillage versus a cover crop (AEM). Our findings show that the incentive could range from the loss of income due to AEM adoption to the ecosystem service benefit (RC_C − RC_AEM). In our case study, the incentive ranged from 315 € ha⁻¹ (loss of income) to 1,088 € ha⁻¹ (ecosystem service benefit). Within this range, the incentive amount is determined according to efficiency criteria based on vineyard slope. We also present a conceptual model of public spending efficiency that should help policy makers decide how to allocate the incentives so as to maximize the economic return associated with ecosystem services. Copyright © 2015 John Wiley & Sons, Ltd.     

Stakeholders' Perceptions about Fire Impacts on Lithuanian Protected Areas

The aim of this work is to study Lithuanian stakeholders' perceptions of fire impacts in protected areas. For this study, the stakeholders consisted of foresters, ecologists and farmers. A clear understanding of the opinions of stakeholders about fire effects on environmental, social and economic aspects of Lithuanian protected areas will allow an assessment of the stakeholders' reaction to fire policy, including government measures towards fire prevention, suppression and application of prescribed fire to landscape management. The results showed that stakeholders in general think that fire is not a threat to Lithuania and to the ecological processes in the protected areas. However, they agree that fires have negative impacts on soil properties and fertility but are not to an irremediable or irrecoverable extent. Stakeholders disagree that fire has positive consequences for agricultural and cattle activities but agreed that vegetation recovers quickly. They do not see fire as a social and economic problem, do not agree that prescribed fire could be used to landscape management, and believe that mechanical thinning is a better management tool than prescribed fire. Stakeholders agree that fire does not have negative impacts on the biodiversity. These opinions depended on the age group of the respondent but especially on the respondent's professional occupation. Copyright © 2014 John Wiley & Sons, Ltd.     

Historical abundance and distributions of Salpa thompsoni hot spots in the Southern Ocean and projections for further ocean warming

1. In contrast to Antarctic krill Euphausia superba, Antarctic salps (Salpa thompsoni) respond positively to warmer water temperatures and have the ability to create massive blooms under favourable conditions. Therefore, they can compete with krill for primary production. Over the last three decades, significant variability in S. thompsoni occurrence has been observed as a response to the environmental fluctuations of the Southern Ocean ecosystem (e.g. changes in sea surface temperature and ice-cover shrinkage around the cold Antarctic waters).
2. This study presents historical abundance data of salps from the south-west Atlantic Sector of the Southern Ocean, covering a time span of 26 years. These data allow tracking of fluctuations in Antarctic salp abundance and their distribution with bottom depth, temperature, and ice conditions, aiming to reveal salp hot spots and to predict the future range of S. thompsoni distribution with upcoming climate warming in the next 50 years.
3. Results showed the highest salp density in shallow shelf waters with ice cover and low temperatures between 1 and −1°C. In the studied area, S. thompsoni hot spots were located mostly around Elephant Island, but also the islands around Brensfield and Gerlache Straits, as well as to the south near the Bellingshausen Sea. Inferences made of future salp distribution suggest that the range of S. thompsoni will move southwards, enlarging their habitat area by nearly 500,000 km², which may have significant implications on the whole Antarctic food web. The information presented herein may be used for Antarctic ecosystem management, protection, and conservation.