New strategies for estimation of cut and fill areas in road design with different ground cross-section offsets

Earthwork operations accounted for great amount of forest road construction costs. Any Optimization in planning road profile needs a reliable objective function that calculates earthwork volume in an appropriate time and accuracy. This study aimed at incorporating the shape of the ground cross sections in calculating cut/fill areas using three alternative methods including: Multiple Linear Regression (MLR), Artificial Neural Network (ANN) and heuristic programming in MATLAB environment. The accuracy of results was validated via AutoCAD as a manual method for area calculation of road’s cross-section. Trapezoidal method applied to calculate the area of cut/fill in the heuristic method. Paired sample T-Test and statistical analysis (ANOVA) with confidence level of 0.95 indicated that the heuristic method not only reduced computing time but also provided accurate estimations as same as the manual AutoCAD based method. It can be concluded that although MLR and ANN estimations were as well as AutoCAD results within a reasonable time, they need to be retrained by adding, removing or changing entrance parameters.     

Prevalence of Brucella abortus antibodies in equines of a tropical region of Mexico

A cross-sectional study was conducted to determinate the seroprevalence rate of equine brucellosis in the state of Tamaulipas, Mexico. Serum samples from 420 equines were analyzed with the Rose Bengal test at cell concentrations of 3% (RBT-3%) and 8% (RBT-8%), and positive results were confirmed with the Rivanol test (RT). Risk factors were determined with the prevalence ratio (PR) and the use of variables generated from a questionnaire administered to the animals' owners. Serum from 1 stallion had positive results with both the RBT-8% and the RT, for a seroprevalence rate of 0.238%. Drinking of water from a pond that was also used by cattle and dogs was the only associated risk factor for this animal (PR = 0.25). However, the results were considered false-positive, because the results for other horses in the same environmental conditions were negative. Although brucellosis is considered endemic in ruminants in the study area, the results obtained suggest that equines are not a reservoir of brucellosis and do not play an important role in the epidemiologic patterns of this disease in northeastern Mexico.     

Mini-cuttings: an effective technique for the propagation of <Emphasis Type="Italic">Pinus pinaster</Emphasis> Ait.

Pinus pinaster Ait. is one of the main forest tree species planted in Spain, Portugal and France. Due to its high economic relevance, there is considerable interest in developing techniques for vegetative breeding aimed at mass propagation. In this study we present a mini-propagation protocol in order to define an efficient method to propagate families or clones of P. pinaster. We carried out three experiments using mini-cuttings of 3–5 cm in length with the aim of evaluating the effects of temperature (4°C vs. 25°C), plant growth regulator (IBA) and shoot age on rooting ability. Percentage of rooted cuttings and morphological root variables were recorded. The percentage of rooted cuttings per treatment ranged from 68 to 97%. Treatment with IBA significantly influenced the rooting process at 25°C but not at 4°C. The number of apexes, length, area and volume of roots were all positively affected by temperature treatment. Shoot age also had a positive effect on rooting capacity of cuttings, with the cuttings from the youngest shoots (70 days after pruning) having higher rooting percentages, ranging from 84.7 to 98.3%. The use of juvenile material, good environmental conditions and IBA all benefited the rooting of clonal material, resulting in high rooting capacity. This study presents an innovative propagation protocol for P. pinaster that can be used as a tool in breeding programs.     

Expression of reproduction and antioxidant-related genes in crayfish Cherax quadricarinatus fed with dietary feed additives

We evaluated the impact of a combined vitamin E (vit E), a mixture of nucleotide (mixed-NT), Haematococcus pluvialis (H. pluvialis), arachidonic acid (AA), and yeast extract powder (YEP) supplementations on the relative mRNA expression of reproduction and antioxidant-related genes in red claw crayfish Cherax quadricarinatus using an orthogonal design (L16 4⁵) plus control diet for 70 days feeding trial. Five factors with four levels: A, vit E ^{40, 160, 240, and 320 mg/kg diet}; B, mixed-NT ^{2, 4, 6, and 8 g/kg diet}; C, H. pluvialis ^{2, 4, 6, and 8 g/kg diet}; D, AA ^{5, 10, 15, and 20 g/kg diet}; E, YEP ^{2.5, 5, 10, and 15 g/kg diet} were studied. The relative mRNA expression of reproduction-related genes (vitellogenin (vtg) and fatty acid-binding protein (fabp)), and antioxidant-related genes (heat shock protein 70 (hsp70), glutathione peroxidase (gpx), glutathione S-transferase (gst), mitochondrial manganese superoxide dismutase (mmnsod), and ferritin) in hemocyte, hepatopancreas, and ovary tissues were measured. There was a major depression in gene expression levels throughout the experimental diet at high vit E ^320 mg/kg level with other factors. Expression of antioxidant enzyme genes significantly increased in treatments of T9, T10, T11, and T12, while significantly decreasing in treatment of T13 and other treatment groups with high vit E ^320 mg/kg levels with the other factors. Gene expression of vtg and fabp demonstrated similar patterns to those of antioxidant genes. These results provide evidence that combined supplementations of vit E, mixed-NT, H. pluvialis, AA, and YEP with vit E ^240 mg/kg, mixed-NT ^8 g/kg, H. pluvialis ^4 g/kg, AA ^5 g/kg, and YEP ^10 g/kg may present a novel strategy for improving reproduction performance and antioxidant activities in RC-crayfish, C. quadricarinatus by the positive impact on the molecular level of reproduction and antioxidant genes.

     

Time Prediction Models and Cost Evaluation of Cut-To-Length (CTL) Harvesting Method in a Mountainous Forest

Time equations are derived for felling with chainsaw, skidding with cable wheeled skidder, loading with grapple hydraulic loader and trucking of logs within a cut-to-length harvesting method. The continuous time study method was applied to collect data for felling, skidding, loading and a transportation model. Multiple regression analysis via SPSS software was applied to develop the time models. Felling time was found to be highly dependent on diameter at breast height. Skidding distance, winching distance, slope of the trail and piece volume were significant variables for the skidding time prediction model. The loading time model was developed considering piece volume. Transportation distance and load volume were used as independent variables in modeling the transportation time. The net production of felling was estimated at 12 trees/h (56.65 m³/h). The net production rates for skidding, loading and traveling averaged 18.51, 41.90 and 3.32 m³/h respectively. The total cost of harvesting from stand to mill was estimated 19.70 €/m³. The skidding phase was the most expensive component of the cut-to-length method. The bucking and delimbing components were less costly than the other logging phases. The results of this study can be used for harvesting planning and productivity optimization.