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91.
Volume estimation of Cryptomeria japonica logs in southern Brazil using artificial intelligence models 总被引:1,自引:0,他引:1
Carlos R Sanquetta Luani RO Piva Jaime Wojciechowski Ana PD Corte 《Southern Forests》2018,80(1):29-36
This study aimed to test taper functions and artificial intelligence (AI) models in order to estimate merchantable volumes of Japanese cedar (Cryptomeria japonica) trees in a homogenous plantation in southern Brazil. A total of 30 individuals were rigorously scaled and their total volumes were calculated, including those of the following log assortments: veneer, sawn, pulp and energy. Three AI models, i.e. two variants of k-nearest neighbours (KNN) instance-based classification (one and three nearest neighbours) and an artificial neural network (ANN) approach, were compared with three traditional taper models: fifth-order polynomial, fractional powers and the Garay model. The estimated volumes were compared with the actual volumes by means of the standard error (Syx), bias, precision and accuracy. Total volume estimates proved to be unbiased (maximum bias 5.42%), precise (maximum precision 9.28%) and accurate (maximum accuracy 10.79%) with all of the investigated models. The tested models tended to give lower bias, better precision and accuracy in the middle portion of the stems, but worse estimates at the base and tip (maximum bias ?12.41%). In general, the KNN models improved merchantable volume estimation, particularly KNN1, which is a straightforward and simple method. We conclude that AI techniques have appeal for application in forest inventories and that KNN is a particularly interesting alternative for tree volume estimation. 相似文献
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Prevalence, spread and control of caprine arthritis-encephalitis virus in dairy goat herds in New South Wales 总被引:1,自引:0,他引:1
SUMMARY A study of the prevalence, spread and control of caprine arthritis-encephalitis virus (CAEV) in dairy goat herds in New South Wales (NSW) during 1986–1988 found that 56.8% of 1484 goats in 14 dairy herds were infected with CAEV. The prevalence of CAEV infection within most herds not implementing control measures increased during the study. At the end of the study, 59.7% of 1322 goats were infected. The prevalence of CAEV increased with age. Differences between breeds were less apparent. Within seven herds with a high standard of identification of goats, 149 of 812 goats seroconverted in an ELISA. Of these newly infected goats, 142 (95.3%) were > 1 yr of age and 96 (64.4%) were > 2 yr suggesting lateral spread of the virus. Most of the goats > 2 yr of age had been in the milking herd for a minimum of 3 to 6 months. The high seroconversion rate within the milking herd suggested that factors other than the ingestion of infected colostrum and milk before weaning were important for the spread of CAEV. Observations indicated that behaviour of goats, particularly reproductive behaviour among lactating does, and milking herd management practices are important in the spread of CAEV. A high density of livestock, poor livestock control and contamination of feed, water, equipment and personnel were implicated in transmission. Poorly functioning milking machines may also be involved. CAEV was eradicated from 3 herds by the implementation of strict control measures. 相似文献
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PD JELINEK T ELLIS RH WROTH SS SUTHERLAND HG MASTERS DS PETTERSON 《Australian veterinary journal》1988,65(7):214-217
SUMMARY: Immunity in 12 weaner Merino sheep fed a low selenium (Se) diet (low Se sheep) was compared with that in 10 matching sheep fed the same diet but each given an intraruminal Se pellet (high Se sheep), while the sheep were housed in individual, sheltered pens. All sheep were challenged with killed Brucella abortus cells (days 0 and 28), rabbit red blood cells (days 0, 7 and 28) and corynebaclerium pseudotuberculosis toxoid (days 0 and 28), and serum antibody titres were measured weekly for 8 weeks from day 0. The sheep were then experimentally infected with Haemonchus conforfus, and slaughtered 8 weeks later. The mean antibody titre to B. abortus, measured by 4 different tests, was significantly higher in the high Se sheep on occasions during the primary immune response phase (Rose Bengal test - day 21 (p < 0.05), day 28 (p < 0.025); complement fixation - day 7 (p < 0.05); enzyme-llnked immunosorbent assay - day 14 (p < 0.01); serum agglutination - no differences), but not during the secondary phase. The mean antibody titre to rabbit red blood cells, measured by haemagglutination test, was marginally higher in the high Se sheep on day 49 (p = 0.049). The mean antibody titre to C. pseudotuberculois, measured by enzyme-linked immunosorbent assay, was not significantly different between the groups at any time during the trial. In addition, the mean invitro responsiveness of peripheral blood lymphocytes to stimulation with phytohaemagglutinin in the high Se sheep was significantly greater than that in 10 sheep from the low Se group on day 22 (p < 0.01), but not day 50. However, there were no significant differences in the mean number of sheep in which the infection with H. contortus established, time to first shedding of eggs in faeces, abomasal worm burdens at necropsy, or inflammatory response in the abomasal mucosa in the sheep in each group. The results showed that the low Se sheep produced strong overall immune responses that were largely comparable to those in the high Se sheep. 相似文献
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María F Martín PD PhD María S Carrasco MD PhD Jesús Usón-Gargallo DVM PhD Juan R Lima DVM Luis J Ezquerra DVM PhD 《Veterinary anaesthesia and analgesia》2001,28(3):132-139
Objective To compare the magnitude and duration of the peri‐operative haematological, endocrine and metabolic effects of surgery performed under sevoflurane anaesthesia. Study Design Prospective randomized study. Animals Ten, 55‐day‐old lambs of both sexes, mean weight 20.8 ± 0.3 kg (range 18.5–23.6 kg). Methods Animals were randomly allocated to two equal groups. All were anaesthetized with sevoflurane for 3 hours. Surgery (end‐to‐end anastomosis of the right carotid artery and right jugular vein) was performed in animals of Group 1 only. The electrocardiogram, pulse oximetry, cardiac output and noninvasive arterial blood pressure (NIBP) were monitored. Venous blood samples (5 mL) were taken 30 minutes before induction of anaesthesia (T = 0) and 1 (T1), 24 (T2), 48 hours (T3) and 7 days (T4) after anaesthesia in order to measure plasma cortisol, ACTH, insulin, cyclic adenosine monophosphate (cAMP), glucose, protein concentrations and haematological variables. Results Sevoflurane decreased NIBP (minimum mean value: 64 ± 3 mm Hg) in both groups. Plasma cortisol and ACTH concentration increased in Group 1 (maximum mean values: cortisol: 136.2 nmol L?1, ACTH: 54.5 pmol L?1) and Group 2 (maximum mean values: cortisol: 128.7 nmol L?1, ACTH: 44.0 pmol L?1). Cyclic AMP increased only in Group 1 (9.3 nmol) 1 hour after anaesthesia. Neutrophilia, lymphopaenia and a decreased PCV were observed in both groups 1 hour after anaesthesia. Plasma protein and glucose concentrations did not change. Conclusions Increased ACTH and cortisol concentrations recorded 1 hour after anaesthesia suggest that sevoflurane induces a stress response in lambs. Clinical relevance The study did not identify the mechanism by which sevoflurane induces a stress response although hypotension is implicated. 相似文献
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Yves PS Moens DVM PD PhD Diplomate ECVAA Peter Gootjes† Ing Jean-Claude Ionita‡ DVM Erkki Heinonen§ Lic Tech PhD & Urs Schatzmann‡ DVM PhD Diplomate ECVAA 《Veterinary anaesthesia and analgesia》2009,36(3):209-219
Objective To remodel and validate commercially available monitors and their Pitot tube-based flow sensors for use in large animals, using in vitro techniques.
Study design Prospective, in vitro experiment.
Methods Both the original and the remodelled sensor were studied with a reference flow generator. Measurements were taken of the static flow-pressure relationship and linearity of the flow signal. Sensor airway resistance was calculated. Following recalibration of the host monitor, volumes ranging from 1 to 7 L were generated by a calibration syringe, and bias and precision of spirometric volume was determined. Where manual recalibration was not available, a conversion factor for volume measurement was determined. The influence of gas composition mixture and peak flow on the conversion factor was studied.
Results Both the original and the remodelled sensor showed similar static flow–pressure relationships and linearity of the flow signal. Mean bias (%) of displayed values compared with the reference volume of 3, 5 and 7 L varied between −0.4% and +2.4%, and this was significantly smaller than that for 1 L (4.8% to +5.0%). Conversion factors for 3, 5 and 7 L were very similar (mean 6.00 ± 0.2, range 5.91–6.06) and were not significantly influenced by the gas mixture used. Increasing peak flow caused a small decrease in the conversion factor. Volume measurement error and conversion factors for inspiration and expiration were close to identity.
Conclusion The combination of the host monitor with the remodelled flow sensor allowed accurate in vitro measurement of flows and volumes in a range expected during large animal anaesthesia.
Clinical relevance This combination has potential as a reliable spirometric monitor for use during large animal anaesthesia. 相似文献
Study design Prospective, in vitro experiment.
Methods Both the original and the remodelled sensor were studied with a reference flow generator. Measurements were taken of the static flow-pressure relationship and linearity of the flow signal. Sensor airway resistance was calculated. Following recalibration of the host monitor, volumes ranging from 1 to 7 L were generated by a calibration syringe, and bias and precision of spirometric volume was determined. Where manual recalibration was not available, a conversion factor for volume measurement was determined. The influence of gas composition mixture and peak flow on the conversion factor was studied.
Results Both the original and the remodelled sensor showed similar static flow–pressure relationships and linearity of the flow signal. Mean bias (%) of displayed values compared with the reference volume of 3, 5 and 7 L varied between −0.4% and +2.4%, and this was significantly smaller than that for 1 L (4.8% to +5.0%). Conversion factors for 3, 5 and 7 L were very similar (mean 6.00 ± 0.2, range 5.91–6.06) and were not significantly influenced by the gas mixture used. Increasing peak flow caused a small decrease in the conversion factor. Volume measurement error and conversion factors for inspiration and expiration were close to identity.
Conclusion The combination of the host monitor with the remodelled flow sensor allowed accurate in vitro measurement of flows and volumes in a range expected during large animal anaesthesia.
Clinical relevance This combination has potential as a reliable spirometric monitor for use during large animal anaesthesia. 相似文献