Optimal management of Korean pine plantations in multifunctional forestry

Korean pine is one of the most important plantation species in northeast China.Besides timber,it produces edible nuts and plantations sequester carbon dioxide from the atmosphere.This study optimized the management of Korean pine plantations for timber production,seed production,carbon sequestration and for the joint production of multiple benefits.As the first step,models were developed for stand dynamics and seed production.These models were used in a simulation–optimization system to find optimal timing and type of thinning treatments and optimal rotation lengths.It was found that three thinnings during the rotation period were optimal.When the amount or profitability of timber production is maximized,suitable rotation lengths are 65–70 years and wood production is 5.5–6.0 m~3 ha~(-1) a~(-1).The optimal thinning regime is thinning from above.In seed production,optimal rotation lengths are over 100 years.When carbon sequestration in living biomass is maximized,stands should not be clear-cut until trees start to die due to senescence.In the joint production of multiple benefits,the optimal rotation length is 86 years if all benefits(wood,economic profits,seed,carbon sequestration) are equally important.In this management schedule,mean annual wood production is 5.5 m~2 ha~(-1) and mean annual seed yield 141 kg ha~(-1).It was concluded that it is better to produce timber and seeds in the same stands rather than assign stands to either timber production or seed production.     

Determining suitability of thermal development models to estimate temperature parameters for embryonic development of <Emphasis Type="Italic">Sitona lepidus</Emphasis> Gyll. (Coleoptera: Curculionidae)

The clover root weevil, Sitona lepidus Gyll. is a pest of clovers (Trifolium spp.), particularly white clover (T. repens). Larva feeding severely impairs the capacity of white clover to fix atmospheric nitrogen, by attacking the nitrogen-fixing root nodules. Development of the egg stage was studied at six different constant temperatures ranging from 9 to 30°C to improve the basis for phenological forecasts. Development occurred over the entire range of temperatures, although hatching percentage at 30°C was only 24.4% compared to 90.1% at 28.5°C. Developmental time decreased with increase in temperature from 9 to 28.5°C but increased markedly at 30°C. At 28.5°C, the embryo development period was the shortest (10.35 days); whereas at 9°C, this parameter was the longest (55.08 days). Using linear regression, the lower threshold temperature was calculated 4.38°C and the thermal constant was 236.45 degree-days. The relationship between constant temperature and developmental rate was evaluated using nine models. The suitability of the models was evaluated based on eight indicators (R ², RSS, R _adj², AIC, BIC, AICC, W _j , and Z _i ). Of the nonlinear models, the Logan-6, Sharpe and DeMichele, and Lactin models were the most accurate at calculating t _opt of 27, 27.50, and 28°C, respectively. The results suggest that of the three models (Lactin, Briere, and Hilbert and Logan), that estimated critical temperatures, (t _min, t _opt, and t _max), Lactin gave the most suitable fit of data. This response of S. lepidus to temperature can be used for developing phonological models to predict the timing of egg hatch which are important for management programs targeting the weevil.     

Alteration of certain blood parameters of freshwater teleost <Emphasis Type="Italic">Mystus vittatus</Emphasis> after chronic exposure to Metasystox and Sevin

Indiscriminate use of pesticides has elevated the risk of contamination of environment and aquatic habitat. Considering the above fact, the present study has been under taken to investigate the alteration of some blood parameters of freshwater teleost Mystus vittatus after chronic exposure to sublethal concentrations of Metasystox (4 ppm.) and Sevin (7 ppm.) individually. The main alterations observed in certain haematological parameters were clotting time (CT), erythrocyte sedimentation rate (ESR), haemoglobin percentage (Hb%), red blood corpuscles (RBCs), white blood corpuscles (WBCs), pack cell volume (PCV), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC). Alterations in organic constituents of blood, such as glucose, blood urea, total plasma protein and cholesterol, and in inorganic constituents, such as calcium, iron, magnesium, and phosphorus, were also studied. Alteration of enzymes such as glucose-6-phosphatase (G-6-pase), fructose-1-6-diphosphatase (F-1-6-dipase), serum glutamic oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT) were also studied, so that the changes in the blood biochemistry due to the pesticidal stress could be understood. Results indicated that CT, WBCs, MCH, MCHC, glucose, blood urea, cholesterol, magnesium and SGOT were increased, whereas other parameters were found to be decreased in both cases. Possible reasons for the above elevation are discussed in the light of available literature.     

Non‐invasive fast real‐time PCR assay for detection of the enteric parasite Enteromyxum scophthalmi in cultured turbot (Scophthalmus maximus L.)

Enteromyxum scophthalmi is a myxozoan parasite that causes severe parasitic diseases in cultured turbot affecting mainly the intestine of the host. It is characterized by producing acute enteritis, starvation and eventually death. Current diagnosis of E. scopthalmi use traditional techniques, based on the identification of the morphology of the parasite. These techniques take extended time to be carried out and do not favour the adoption of control measure at turbot farms and require the sacrifice of fish. This study develops a fast real‐time PCR molecular tool for the detection of E. scophthalmi in infected farmed turbot. This methodology is applicable for routine controls on the farm at every stage of the parasite infection. Results of the study demonstrate the robustness, specificity, efficiency and reliability of the technique. In addition, this study also provides a non‐invasive procedure of sampling through swaps. This allows control, prevention and diagnosis of the parasite infection at turbot farms while maintaining the welfare of the cultivated fish and avoiding sacrifice of the fish sampled.     

Growth traits of four maternal lines of rabbits founded on different criteria: comparisons at foundation and at last periods after selection

The objective was to compare growth traits in four maternal lines of rabbits (A, V, H and LP), with the aim of understanding the consequence of the different foundation and selection processes on the growth performance of the lines. The lines are currently in the 43th, 38th, 22th and 8th generations, respectively. Two comparisons were performed. One compared the values of the lines at their foundation, using the complete data set, the full pedigree and a two‐trait analysis, including data on the selection criteria, litter size. The other comparisons were done during the last period when all the lines were housed together with the same feeding and management. The numbers of records were 323 208 for weaning weight, and 300 553 for slaughter weight and average daily Gain (from 46 708 l). The pedigree file included 346 638 animals. The second analysis used only the data corresponding to each period, and the analysis was conducted using a one‐trait model. The model was the same as that defined for the comparisons at the foundation, but the additive effects were excluded. The H and LP lines showed highest values for all the traits compared. In the last periods, a good agreement was observed between the estimated differences, computed with the complete model and data set, or computed with an incomplete model and only data from the comparison period. At last periods, the differences were smaller than at foundation. The importance of the correlated response in growth after selection for litter size at weaning or the importance of a non‐programmed intramating selection for the growth traits can explain the changes since foundation.     

Cryopreservation of Dog Semen in a Tris Extender with 1% or 2% Soya Bean Lecithin as a Replacement of Egg Yolk

Egg yolk is usually included in extenders used for preservation of dog semen. Lecithin is an interesting animal‐protein free alternative to egg yolk for semen preservation. The aim of our study was to evaluate soya bean lecithin for cryopreservation of dog semen. Five ejaculate replicates were divided in three equal parts, centrifuged and each pellet diluted with one of the three Tris‐based extenders containing 20% egg yolk, 1% soya bean lecithin or 2% soya bean lecithin. Extended semen was loaded in 0.5‐ml straws, cooled and diluted a second time and frozen in liquid nitrogen vapours. Sperm motility parameters (CASA), acrosome integrity (FITC‐PNA/PI) and sperm membrane integrity (C‐FDA) were evaluated 5 min post‐thaw and after 2 and 4 h of incubation. Total motility was significantly better in the egg yolk extender than in any of the lecithin‐based extender and was better in the 1% lecithin extender than in the 2% lecithin extender. Sperm membrane integrity was significantly better in the egg yolk extender than in any of the lecithin‐based extenders but did not differ significantly between the 1% and 2% lecithin extenders. Acrosome integrity was significantly better in the egg yolk extender than in the 2% lecithin extender but did not differ between the egg yolk extender and the 1% lecithin extender or between the two lecithin extenders. In conclusion, egg yolk was superior to lecithin in our study. The extender with 1% lecithin preserved sperm motility better than the extender with 2% lecithin.     

Chronological study of Mycoplasma hyopneumoniae infection, seroconversion and associated lung lesions in vaccinated and non-vaccinated pigs

A field trial was conducted to study Mycoplasma hyopneumoniae (Mh) infection dynamics by nested polymerase chain reaction (nPCR) and serology in pigs of a farm affected by enzootic pneumonia (EP). Moreover, correlation of Mh detection at different respiratory tract sites with presence of EP gross and microscopic lung lesions was assessed. These parameters were studied and compared between vaccinated (two doses at 1 and 3 weeks of age versus one dose at 6 weeks of age) and non-vaccinated pigs. Animals were monitored from birth to slaughter by nPCR from nasal swabs and by serology. From 3 to 22 weeks of age, an average of three pigs per treatment and per batch were necropsied (n = 302). The remaining pigs were sent to the slaughter (n = 103). Nasal, bronchial and tonsillar swabs were taken from the necropsied/slaughtered pigs; gross and microscopic EP-suggestive lung lesions were also assessed. Single and double vaccination resulted in earlier seroconversion and higher percentage of Mh seropositive pigs compared to control group. At slaughter, double vaccinated pigs showed lower percentage of EP-compatible gross lung lesions and lower Mh prevalence at upper respiratory tract sites (nasal cavity and tonsil) than control pigs.     

Black nightshade (<Emphasis Type="Italic">Solanum nigrum</Emphasis>) emergence and development is affected by seed density and burial depth

Black nightshade (Solanum nigrum L.) is a troublesome weed worldwide, affecting a large number of crops. As weed development is affected by a variety of factors, advanced knowledge on the plant’s biological and ecological qualities can support favorable management strategies. Seed density is an ecological factor affecting emergence and early growth of many weed species. For that reason, the current study characterizes and quantifies the seed density impact on black nightshade seedling-emergence and early growth, and the interaction between seed density and burial depth on these growth parameters. Greenhouse studies conducted in 2005, 2006 and 2010 examined black nightshade seed densities of 1, 5, 10, 25 and 50 seeds per pot, buried at, 1, 2, 3, 4 and 5 cm. Impact of seed density on weed emergence and growth was characterized by number of emerged plants and leaves, followed by biomass measurements. Seed density had no impact on emergence at the tested burial depths. There was a strong logistic relationship (P < 0.001, and R ²  > 0.97) between time and emergence, and a strong linear relationship (P < 0.002 and R ²  > 0.86) between time and number of leaves produced in all depths and seed densities. A negative relationship was observed between seed density and plant development and growth rate. Results of this study extend the knowledge on black nightshade biology and support decision-making concerning rational weed management.     

Sedimentary records of the Zrmanja River estuary,eastern Adriatic coast—natural vs. anthropogenic impacts

Purpose

Investigations of geochemical characteristics of sediments of the Zrmanja River estuary were done in order to determine the natural and anthropogenic factors influencing sediment composition in this area. For that purpose, spatial and temporal distribution of major and trace elements in the sediments and surrounding soils was studied.

Materials and methods

Sediment and soil samples, including one marl sample, were collected at 28 locations. All samples were subjected to total digestion and subsequently analysed by high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) for total concentration of 20 elements (Ag, Al, As, Be, Ca, Cd, Co, Cr, Cu, Fe, Li, Mn, Ni, Pb, Rb, Sb, Sn, Sr, Ti and Y). Obtained concentrations and their normalized counterparts were used for assessment of factors influencing sedimentation in the study area.

Results and discussion

The results of the analysis showed that the composition of sediments of the Zrmanja River estuary is primarily determined by the composition of bedrock, existing hydrodynamic conditions and the relative isolation of the studied basin. Nevertheless, anthropogenic influences were observed as well. The composition of the Zrmanja River sediments reflects the impact of the ex-alumina factory “Jadral” and transfer by wind of the material from its immediate surroundings to the water system of the Zrmanja River. In addition, sedimentation in the Zrmanja River was found to be influenced by the construction of reservoirs and the HE “Velebit”, hydroelectric power plant located in the Zrmanja watershed.

Conclusions

The geochemical composition of recent sediments of the Zrmanja River estuary is controlled primarily by natural factors, although the influence of anthropogenic activities is also evident.

     

Chemical authentication of extra virgin olive oil varieties by supervised chemometric procedures.

This work has focused on discriminating extra virgin olive oils from Sabina (Lazio, Italy) by olive fruit variety (cultivar). A set of oils from five of the most widespread cultivars (Carboncella, Frantoio, Leccino, Moraiolo, and Pendolino) in this geographical area was analyzed for chemical composition using only the Official Analytical Methods, recognized for the quality control and commercial classification of this product. The obtained data set was converted into a computer-compatible format, and principal component analysis (PCA) and a method based on the Fisher F ratio were used to reduce the number of variables without a significant loss of chemical information. Then, to differentiate these samples, two supervised chemometric procedures were applied to process the experimental data: linear discriminant analysis (LDA) and artificial neural network (ANN) using the back-propagation algorithm. It was found that both of these techniques were able to generalize and correctly predict all of the samples in the test set. However, these results were obtained using 10 variables for LDA and 6 (the major fatty acid percentages, determined by a single gas chromatogram) for ANN, which, in this case, appears to provide a better prediction ability and a simpler chemical analysis. Finally, it is pointed out that, to achieve the correct authentication of all samples, the selected training set must be representative of the whole data set.