Variation in log quality and prediction of sawing yield in oak wood (Quercus robur)     

Guillermo Riesco Muñoz  Andrés Remacha Gete  Manuel Gasalla Regueiro 《Annals of Forest Science》2013,70(7):695-706

Context

The commercial feasibility of sawmilling depends on the expected volume and value of sawn planks. Models that predict the volume of sawn timber of a particular quality and produced from logs of known characteristics are therefore very useful.

Aims

The objectives were to study variation in sawing yield and to obtain models that predict lumber volume and grade recovery on the basis of easy-to-measure predictor variables of saw logs.

Methods

Forty-six oak trees growing in Galicia (NW Spain) were felled and cut into logs. The logs were visually graded and sawn mainly into quartersawn planks, which were dried, planed and visually graded for structural purposes.

Results

The total volumetric sawing yield was 47.6 %. The sawing yield for planks of structural dimensions (cross-section, 70?×?120 or 70?×?170 mm) was 43.4 %, but decreased to 8.4 % for structural sized and quality grade beams because of wane and biotic damage in many pieces. Log grade did not significantly affect sawing yield in the sample analysed, despite the wide range of diameter over bark at the smallest end in the sampled logs (22–77 cm). The sawing pattern affected total sawing yield (F?=?4.913; p value?=?0.001) and the sawing yield for structural planks (F?=?6.142; p value?=?0.0002); radial sawing with one cut and live sawing of half logs provided the highest yields. Three models were proposed for estimating sawn volume in timber products, with the small-end log diameter over bark as the predictor variable and R _adj ² between 0.31 and 0.78 (p value?<?0.01).

Conclusion

For the purpose of producing oak timber destined for structural use, the presence of bark and sapwood in planks must be reduced in the sawing process; this would decrease the total lumber recovery but increase the timber value yield. Air drying must be accelerated to reduce biotic damage in sawn planks. Geometric mean diameter over bark at the smallest end (d) outperforms other measures as a predictor variable for total or structural sawn timber volume.  相似文献   

Plant species richness and ecosystem multifunctionality in global drylands     

Maestre FT  Quero JL  Gotelli NJ  Escudero A  Ochoa V  Delgado-Baquerizo M  García-Gómez M  Bowker MA  Soliveres S  Escolar C  García-Palacios P  Berdugo M  Valencia E  Gozalo B  Gallardo A  Aguilera L  Arredondo T  Blones J  Boeken B  Bran D  Conceição AA  Cabrera O  Chaieb M  Derak M  Eldridge DJ  Espinosa CI  Florentino A  Gaitán J  Gatica MG  Ghiloufi W  Gómez-González S  Gutiérrez JR  Hernández RM  Huang X  Huber-Sannwald E  Jankju M  Miriti M  Monerris J  Mau RL  Morici E  Naseri K  Ospina A  Polo V  Prina A  Pucheta E 《Science (New York, N.Y.)》2012,335(6065):214-218

Experiments suggest that biodiversity enhances the ability of ecosystems to maintain multiple functions, such as carbon storage, productivity, and the buildup of nutrient pools (multifunctionality). However, the relationship between biodiversity and multifunctionality has never been assessed globally in natural ecosystems. We report here on a global empirical study relating plant species richness and abiotic factors to multifunctionality in drylands, which collectively cover 41% of Earth's land surface and support over 38% of the human population. Multifunctionality was positively and significantly related to species richness. The best-fitting models accounted for over 55% of the variation in multifunctionality and always included species richness as a predictor variable. Our results suggest that the preservation of plant biodiversity is crucial to buffer negative effects of climate change and desertification in drylands.  相似文献   

Procedural sedation combined with locoregional anesthesia for orthopedic surgery of the pelvic limb in 10 dogs: case series     

Campoy L  Martin-Flores M  Ludders JW  Gleed RD 《Veterinary anaesthesia and analgesia》2012,39(4):436-440

HistoryTen dogs weighing 36 (21.4–75) kg [median (min–max)] and aged 3 (1–9) years scheduled for orthopedic surgery involving the stifle and structures distal to it.Physical ExaminationPatients were classified as ASA I or II based on physical examination and basic hematology and biochemistry.ManagementEach dog was managed using combined femoral and sciatic nerve blocks and procedural sedation with an intravenous infusion of propofol (0.07–0.15 mg kg^?1 minute^?1) and dexmedetomidine (1 μg kg^?1 hour^?1). None of the patients required conversion to general anesthesia as a result of response to surgical stimulation. The level of sedation was considered adequate in all patients and was characterized by occasional head lifting, thoracic limb stretching, yawning, lingual movements and swallowing. The eye position ranged from central to partial ventromedial rotation and was accompanied by spontaneous blinking. Intra-operative cardiovascular and ventilatory variables were considered within acceptable limits. Muscle relaxation at the surgical field was adequate and surgical conditions were indistinguishable from those produced by general anesthesia. Intraoperatively, no additional analgesics were considered necessary. The quality of the recoveries was considered excellent in all cases.Follow upNo additional pain relief was required in any of the dogs within the 10 hours following blockade. All dogs ate 5.5 (3.5–12) hours after recovery. Ambulation occurred at 4 (2–6) hours. No evidence of esophagitis or aspiration pneumonitis has been reported during a period of 1 year after the procedures in any of the dogs.ConclusionWhen combined with femoral and sciatic nerve blocks, procedural sedation has the potential of being an alternative to general anesthesia for orthopedic surgery involving the stifle and structures distal to it in the dog.  相似文献   

Survival to prescribed fire of plantation-grown Corsican black pine in northern Portugal   总被引：1，自引：0，他引：1  

Paulo M. Fernandes  Manuel M. Fernandes  Carlos Loureiro 《Annals of Forest Science》2012,69(7):813-820

Context

The current fire regime threatens black pine (Pinus nigra Arn.) persistence in the Mediterranean Basin, which recommends larger-scale fuel treatments. Prescribed burning is an option for stand protection but its use in young stands (which are particularly at risk) is hindered by the scarce knowledge on post-fire tree survival.

Aims

The objectives were to characterize bark thickness as a fire-resistance trait in P. nigra and to describe how post-fire tree survival responds to tree size and fire effects in a 16-year-old plantation.

Methods

Bark thickness was related to diameter at breast height and height in the stem. Metrics describing tree size and stem and crown damage were measured 1?year after prescribed burning in 259 trees. Tree survival was modeled with logistic regression and Classification and Regression Tree analysis.

Results

Bark thickness increased linearly with diameter at breast height (dbh) and decreased with height in the stem. Tree survival was primarily a function of crown injury. Stem damage was an influent factor in small trees.

Conclusion

Due to thinner bark and lower tolerance to crown damage, young P. nigra trees are less fire-resistant than other Mediterranean pines, e.g., Pinus pinaster. Prescribed fire should not be attempted if dbh <10?cm. Mechanical clearing is the treatment of choice in young stands with a significant shrub layer.  相似文献   

Micro-computed tomography of the head and dentition in cadavers of clinically normal rabbits     

De Rycke LM  Boone MN  Van Caelenberg AI  Dierick M  Van Hoorebeke L  van Bree H  Gielen IM 《American journal of veterinary research》2012,73(2):227-232

  相似文献   

Modulation of innate immunity in chickens induced by in vivo administration of baculovirus     

Chimeno Zoth S  Carballeda JM  Gómez E  Gravisaco MJ  Carrillo E  Berinstein A 《Veterinary immunology and immunopathology》2012,145(1-2):241-247

Baculoviruses stimulate cytokine production in mammalian cells. They induce a strong innate immune response in animals and have adjuvant properties. The purpose of this work was to study the in vivo effect of baculovirus on chicken innate immune response. SPF chickens were inoculated intravenously with Autographa californica nuclear polyhedrosis virus (BV). Three hours later, chickens were bled, euthanized and their spleen, duodenum and cecal tonsils were excised in order to take samples for RNA extraction and real time PCR, and to isolate lymphocytes, which were stained and analyzed by flow cytometry. The results obtained showed that baculovirus inoculation up-regulates the expression of IFN-γ, IL-6 and LITAF in spleen cells. This result (IFN-γ) correlated with that obtained by ELISA which showed a very strong increase of IFN-γ in chicken plasma. Flow cytometry analysis revealed that BV inoculation induced in spleen an increase in the percentage of monocyte/macrophage population together with an increase in CD3(+)CD4(+) T lymphocytes. On the other hand, BV inoculation decreased the percentage of CD3(+)CD4(+) T lymphocytes and increased the percentage of NK cells in cecal tonsils. However, intraepithelial lymphocytes of the gut did not show differences between BV and control treated animals. Even though further studies in order to understand the mechanisms by which BVs affect the avian immune response are needed, results obtained in the present work demonstrate the ability of BVs to stimulate the innate immunity in chickens, modifying the expression pattern of related genes and the profile of the immune cells involved.  相似文献   

Physiological effects of glyphosate over amino acid profile in conventional and transgenic soybean (Glycine max)     

Carlos Alberto Moldes  José Manuel Camiña  Leonardo Oliveira MediciSiu Mui Tsai  Ricardo Antunes Azevedo 《Pesticide biochemistry and physiology》2012,102(2):134-141

This paper compares the responses of conventional and transgenic soybean to glyphosate application in terms of the contents of 17 detectable soluble amino acids in leaves, analyzed by HPLC and fluorescence detection. Glutamate, histidine, asparagine, arginine + alanine, glycine + threonine and isoleucine increased in conventional soybean leaves when compared to transgenic soybean leaves, whereas for other amino acids, no significant differences were recorded. Univariate analysis allowed us to make an approximate differentiation between conventional and transgenic lines, observing the changes of some variables by glyphosate application. In addition, by means of the multivariate analysis, using principal components analysis (PCA), cluster analysis (CA) and linear discriminant analysis (LDA) it was possible to identify and discriminate different groups based on the soybean genetic origin.  相似文献   

Seasonal evolution of water status after outplanting of two provenances of Holm oak nursery seedlings     

Enrique Andivia  Felipe Carevic  Manuel Fernández  Reyes Alejano  Javier Vázquez-Piqué  Raúl Tapias 《New Forests》2012,43(5-6):815-824

Forest restoration programs using Holm oak (Quercus ilex ssp. ballota [Desf.] Samp.) have had limited success. The effect of plant provenance on plantation success is uncertain, although some previous studies suggest that some provenances may be better able to tolerate stress. We studied the tolerance to drought in seedlings from two Spanish provenances of Holm oak before and after outplanting. One provenance was from a continental climate with cold winters (GR) and the other was from a xeric climate (HU). Seedlings were subjected to a water stress test in the nursery during the summer and survival was visually assessed after 2?weeks. In addition, 35 healthy seedlings of each provenance that were not subjected to the water stress tests were used for outplanting experiment. In these plants the seasonal changes in water potential at dawn (Ψ), specific leaf area (SLA), cuticular transpiration (E_c), and loss of xylem hydraulic conductance of twigs (PLC) were measured over 18?months. After the water stress test in summer, mortality was 44.3?% for GR seedlings and 12.6?% for HU seedlings. In addition there were differences between the two provenances in plant water status after planting. The HU provenance had a better water status and was more water conservative in the summer (higher Ψ, lower E_c, lower PLC), but not in the winter. The different drought tolerance and water relations parameters of these two provenances indicate that provenance should be considered in forest restoration and conservation programs involving Holm oak.  相似文献   

Evidence for BTV-4 circulation in free-ranging red deer (Cervus elaphus) in Cabañeros National Park, Spain     

Falconi C  López-Olvera JR  Boadella M  Camarena J  Rosell R  Alcaide V  Vicente J  Sánchez-Vizcaíno JM  Pujols J  Gortázar C 《Veterinary microbiology》2012,159(1-2):40-46

Bluetongue (BT) is an infectious disease of wild and domestic ruminants caused by bluetongue virus (BTV). BTV-4 spread through southern Spain from 2004 to 2006, whereas a BTV-1 outbreak that started in southern Spain in 2007 is still ongoing. Vaccination and movement restriction regulations are applied to domestic ruminants to control BT, but the potential reservoir role of wild European ungulates has not been clarified so far. The aim of this study was to describe the epidemiology of BTV in the wild free-ranging red deer (Cervus elaphus) population of Caba?eros National Park (CNP) in central Spain during the BTV-4 and BTV-1 epizootics, assessing the potential role of this deer population as a BTV reservoir. Blood samples from 2885 (2542 adults, 208 calves and 135 undetermined) wild red deer were collected from 2005 to 2010 in CNP and surrounding hunting estates. All sera were tested for antibodies against the BTV VP7 protein by ELISA. Ninety-four of the ELISA-positive samples were analysed by serum neutralization to detect BTV-4 and BTV-1 specific antibodies, and 142 blood samples were analysed by RT-PCR for BTV RNA. A total of 371 (12.9%) out of the 2,885 deer (35/208 calves, 307/2,542 adults, and 29/135 undetermined) were positive for antibodies against BTV. Prevalence increased in adult deer from 2005-2006 to 2008-2009, declining thereafter. No positive samples for BTV-1 were found by serum neutralization, whereas 43 deer (38 adults, four calves and one undetermined) were positive for BTV-4 specific antibodies. No BTV RNA positive deer were found by RT-PCR. Antibody detection throughout the study period suggests a maintained circulation of BTV in red deer. However, the lack of BTV RNA detection suggests a minor transmission risk to livestock.  相似文献   

Cutaneous adverse reaction to furosemide treatment: new clinical findings     

Ochoa PG  Arribas MT  Mena JM  Pérez MG 《The Canadian veterinary journal. La revue veterinaire canadienne》2006,47(6):576-578

A poodle was admitted for investigation of pruritus and a lesional pattern of erythema and alopecia located in the dorsolumbar area. After differential diagnosis ruling out several processes a rare side effect to furosemide, not yet described in canine medicine was confirmed as the possible causative agent.  相似文献