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61.
We investigated the efficiency of three different methods to restrict sprouting in European aspen (Populus tremula L.) in regeneration areas of spruce in Finland. The methods compared were (1) traditional method (cutting at 10?C15 cm height) (2) cutting at 1 m height, and (3) fungus treatment (cutting at 10?C15 cm height, and mycelium of a white-rot fungus, Chondrostereum purpureum [Pers. Ex Fr.] Pouzar was applied to freshly cut stumps). The results indicated that the fungus treatment can restrict the emergence and growth of stump sprouts better than other methods, whereas cutting at 1 m seemed to yield the lowest numbers of root suckers. However, differences between the treatments were not significantly different (P values were > 0.05). For future experimentation, we suggest that the cutting of higher stumps to control the number of root suckers should be combined with application of C. purpureum to restrict the emergence and growth of stump sprouts. We also suggest developing more efficient C. purpureum isolates to control European aspen stump sprouting.  相似文献   
62.
Fragmentation of forest ecosystems increases the proportion of edge habitat and is accompanied by a change in plant species composition. The recreational use of urban forests leads to decreased vegetation cover and the formation of paths, and thus, to fragmentation at small scales. We studied the impacts of forest and path edge effects on the soil microbial community structure (by using the phospholipid fatty acid (PLFA) method) and microbial activity (measured as basal respiration) in 34 mesic boreal urban forest fragments in Finland. We sampled the humus layer 1) from the forest edge into the interior (0–80 m), and 2) at different distances from paths. Microbial community structure was only slightly affected by the forest edge but differences were found between distances of 0–10 m and over 50 m from the edge. These changes correlated with changes in soil pH. Although changes in the microbial community structure were not pronounced, microbial biomass and activity were 30–45% lower at the first 20 m into the forest fragments, due to a low moisture content of the humus near the edge. The decreased microbial activity detected at forest edges implies decreased litter decomposition rates, and thus, a change in ecosystem nutrient cycling. The microbial community structure differed between paths and surrounding areas and correlated with changes in soil pH. Paths also supported approximately 25–30% higher microbial biomass with a transition zone of at least 1 m from the path edge. Path associated disturbances (mainly alterations in vegetation and soil pH) were reflected in the soil microbial community structure up to 1.5 m from the paths.  相似文献   
63.
Five centimeter segments of the linea alba in mature, female, mixed breed dogs were incised and then approximated with either stainless steel fascial staples or size 0 polypropylene suture material. Breaking strength of the linea alba closures was determined at 0 (Phase I, 18 dogs) and at 7,14, and 31 days (Phase II, 18 dogs). Histology and videointeractive planar morphometry were used to evaluate healing of the linea alba. Breaking strength and histologic and morphometric variables were analyzed statistically using analysis of variance in a split plot design. In a clinical trial, 20 cm linea alba incisions were approximated with stainless steel fascial staples after elective ovariohysterectomy in mature, female, mixed breed dogs (Phase III, eight dogs). The dogs were evaluated at 1, 2, 7,14, 31, 90, and 180 days. Linea alba incisions approximated with polypropylene suture material were significantly stronger than linea alba incisions approximated with stainless steel fascial staples on day 0. There was no significant difference between breaking strength values, histologic, and morphometric appearance of linea alba incisions closed with stainless steel fascial staples or polypropylene suture material when compared 7,14, and 31 days after surgery. All of the dogs in the clinical trial appeared to be normal at all evaluation times. Approximation of linea alba incisions with stainless steel fascial staples compares favorably to closure with a simple continuous pattern of polypropylene suture material with regard to breaking strength, clinical, histologic, and morphometric appearance.  相似文献   
64.
Anesthesia was induced in 14 greyhounds with a mixture of diazepam or midazolam (0.28 mg/kg) and ketamine (5.5 mg/kg), and maintained with halothane. There were no significant differences in weight, age, or duration of anesthesia between the treatment groups. Time to intubation with diazepam-ketamine (4.07 +/- 1.43 min) was significantly longer than with midazolam-ketamine (2.73 +/- 0.84 min). Heart rate, respiratory rate, PaCO2, and arterial pH did not vary significantly during anesthesia in either treatment group. Arterial blood pressures, PaO2, halothane vaporizer setting, and body temperature changed significantly from baseline values in both treatment groups during anesthesia. Times to sternal recumbency and times to standing were not significantly different. These data suggest that both diazepam-ketamine and midazolam-ketamine are useful anesthetic combinations in greyhounds. In combination with ketamine, midazolam offers little advantage over diazepam.  相似文献   
65.
Four horses (aged 1 to 18 years) with no apparent respiratory or cardiovascular abnormalities underwent thoracotomy and partial resection of a cranial lung lobe. A stapling instrument was used. Pulmonary function testing prior to and 30 days following surgery showed no significant change in inspiratory or expiratory resistance, compliance, or work of breathing. Postoperative complications consisted of a mild pneumothorax in all horses and localized incisional infection in two horses. All horses displayed a temporary decrease in forward motion of the forelimb on the operated side. Postmortem examination was performed 30 days after surgery; pleural thickening and adhesions between the lung and thoracotomy site were found. The excisionai margin of each cranial lobe was straight with slight puckering due to multiple surgical wire staples. Adjacent tissue collapse and compression were confined to an area no greater than 1 cm from the staples. Beyond this compression, the remaining lung at the surgical site was histologically normal. Subsequently, one horse suffering from recurrent episodes of clinical signs attributed to pleuropneumonia underwent left thoracotomy and partial lung resection followed by a right thoracotomy 48 days later. The horse's condition improved postoperatively, and he was able to undergo normal conditioning and racing.  相似文献   
66.
Polycaprolactone (PCL), a synthetic polyester, was investigated as an interpositional material to delay bone healing following partial ulnar osteotomies. Bone healing did not occur in 6 of 10 osteotomy sites 8 to 24 weeks following surgery in which a PCL cap was placed over the proximal cut end of the ulna, or in four of six ostectomy sites filled with melted PCL that hardened into a plug. Bone healing occurred in ulnectomy sites in which technical problems in positioning and stabilizing the polymer implants occurred. The PCL was well tolerated by the dogs and was an effective mechanical barrier to tissue bridging when adequately stabilized.  相似文献   
67.
Plate luting, a new method of interfacing a compression plate to bone for the repair of fractures, was proposed as a method to help facilitate immediate full weight bearing following internal fixation with plates and screws in horses. Theoretical mechanisms relating bone-plate contact and screw support were discussed. Preliminary mechanical testing showed increased endurance of luted bone-plate composites to cyclic loading when compared with the same devices without plate luting. Screw loosening, which often precedes plate failure, did not occur. In vivo studies showed results similar to in vitro experiments.  相似文献   
68.
Ununited epiphyses were seen in the calcanei of a 13-month-old Rottweiler with abnormal rear limb conformation. Histologic examination of the tissues showed a nonunion with neoarthrosis formation. Surgical management included use of tension band and lag screw techniques to achieve epiphysiodesis that was radiographically evident 12 weeks postsurgery. There was no sign of lameness when examined 8 months after surgery. Similarities exist between this case and that of osteochondrosis in other domestic species, and with Osgood-Schlatters disease in humans. Osteochondrosis and/or abnormal angulation of the hocks were suspected as the underlying cause of the epiphyseal separations.  相似文献   
69.
The search for a better and safer technique for roentgenographic opacification of the canine bronchial tree led to experimentation with metrizamide insufflation. Because metrizamide may be obtained in a microparticulate powdered form, it was postulated that oxygen pressure deliver through a powder blower connected to a selective bronchial catheter would produce a diagnostic quality bronchogram. Metrizamide was used because of its biologically inert, water soluble properties.
The delivery system consisted of a DeVilbiss No. 175 Powder Blower attached to an oxygen clinder with pressure regulator. A soft polyethylene catheter with flexible wire guide was used for selective bronchial catheterization under fluoroscopic control. Oxygen pressure for delivery was kept below 20 pounds/in2, and oxygen flow was controlled by a footswitch.
Insufflation was performed with the animal in ventrodorsal recumbency. Three to eight grams of metrizamide were selectively delivered to the left caudal, right caudal, and accessory lung lobes in 0.5-to 1.0 second bursts over a period of 1–5 minutes.
Powder deposition in subsegmental bronchi was adequate when the insufflation catheter was placed in primary bronchi. Cranial lobe bronchi could be opacified by gravity directed flow of contrast medium-laden bronchial mucous. Alveolarization and radiographic clearing of me-trizamide from the pulmonary field occurred within 30 to 60 minutes.
No insufflation-induced radiographic lesions were recognized. Gross necropsy did not reveal lesions associated with insufflation. Histopathologic examination showed mild multifocal lesions of pneumonitis.  相似文献   
70.
The medical management of three horses with simple and strangulating small intestinal obstructions was unsuccessful and was therefore supported by surgical bypasses. Jejunocecostomies were used to treat horses with postoperative paralytic ileus that was unresponsive to medical management. These horses had abdominal pain, gastric distention, heart rate elevations greater than 60/minute, and small intestinal distention on rectal palpation. Two horses experienced weight loss which responded to bypass removal. The bypass effectively decreased the need for intravenous fluid administration and repeated nasogastric intubation.  相似文献   
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