排序方式: 共有17条查询结果,搜索用时 46 毫秒
1.
2.
Churchward CP Hlúšek M Nicholas RA Ayling RD McAuliffe L 《Veterinary microbiology》2012,159(1-2):257-259
Mycoplasma mycoides subspecies mycoides small colony is the aetiological agent of contagious bovine pleuropneumonia, a cattle disease endemic to areas of sub-Saharan Africa. Twenty isolates from various geographical locations and the type strain were analysed by multi-locus sequence analysis (MLSA). The data generated was then used to develop three PCR primer sets to differentiate these isolates. The PCRs differentiated the isolates into four groups; the type strain (T); isolates of European origin (Eu); isolates from Tanzania (Af1) with a final group consisting of isolates from Namibia and Botswana (Af2). These PCRs offers a rapid and efficient post-identification typing method without the need to sequence and analyse multiple genes. 相似文献
3.
? Context
Secondary Norway spruce forests in the Western Beskids are among the most damaged forests in Europe. Although spruce bark beetle (Ips typographus) has been recently causing large-scale damage to these forests, our understanding of I. typographus dynamics in this environment is inadequate for evaluating forest sustainability.? Aim
This study aims to evaluate the patterns of damage caused by I. typographus to spruce forests with compromised ecological stability.? Methods
Forest infestation by I. typographus was inferred from sanitary felling data collected from 1998 to 2004. Stand and site data were obtained from forest management plans. Spatial-dependence analysis, ordinary kriging and neural network-based regression modelling were used to investigate the patterns of infestation and the casual relationships in the studied ecosystem.? Results
I. typographus long-distance dispersal substantially decreased with outbreak culmination. The spread of infestation was only weakly related to stand and site parameters. Infestations spread isotropically at the stand and patch level but directionally at the regional scale.? Conclusions
The large-scale spread of infestation can be explained by the uniform age and species composition of the investigated forests and by the ability of populations to overwhelm suboptimal trees. The observations presented here suggest that secondary spruce forests in Europe may be unsustainable due to unprecedented bark beetle outbreaks, which can be further amplified by changing climate. 相似文献4.
Martin Mikoláš Martin Tejkal Tobias Kuemmerle Patrick Griffiths Miroslav Svoboda Tomáš Hlásny Pedro J. Leitão Robert C. Morrissey 《Landscape Ecology》2017,32(1):163-179
Context
Distribution and connectivity of suitable habitat for species of conservation concern is critical for effective conservation planning. Capercaillie (Tetrao urogallus), an umbrella species for biodiversity conservation, is increasingly threatened because of habitat loss and fragmentation.Objective
We assessed the impact of drastic changes in forest management in the Carpathian Mountains, a major stronghold of capercaillie in Europe, on habitat distribution and connectivity.Methods
We used field data surveys with a forest disturbance dataset for 1985–2010 to map habitat suitability, and we used graph theory to analyse habitat connectivity.Results
Climate, topography, forest proportion and fragmentation, and the distance to roads and settlements best identified capercaillie presence. Suitable habitat area was 7510 km2 in 1985; by 2010, clear-cutting had reduced that area by 1110 km2. More suitable habitat was lost inside protected areas (571 km2) than outside (413 km2). Habitat loss of 15 % reduced functional connectivity by 33 % since 1985.Conclusions
Forest management, particularly large-scale clear-cutting and salvage logging, have substantially diminished and fragmented suitable capercaillie habitat, regardless of the status of forest protection. Consequently, larger areas with suitable habitat are now isolated and many patches are too small to sustain viable populations. Given that protection of capercaillie habitat would benefit many other species, including old-growth specialists and large carnivores, conservation actions to halt the loss of capercaillie habitat is urgently needed. We recommend adopting policies to protect natural forests, limiting large-scale clear-cutting and salvage logging, implementing ecological forestry, and restricting road building to reduce forest fragmentation.5.
Tomáš Hlásny Ivan Barka Joerg Roessiger Ladislav Kulla Jiří Trombik Zuzana Sarvašová Tomáš Bucha Miroslav Kovalčík Tomáš Čihák 《European Journal of Forest Research》2017,136(5-6):1013-1028
Steadily increasing damage to Norway spruce forests in Europe has caused researchers and managers to consider whether these forests can be converted to more stable ecosystems. In a central European mountain region, we investigated whether management systems (MSs) specified by regional stakeholders provide sound alternatives to the currently applied management. We used the forest model Sibyla to explore whether the tested MSs differ in their sensitivity to climate change in terms of altered biomass production, stand structure, forest damage, and financial outcome. The tested MSs were no-management (NM), currently applied management (BAU), and management based on the preferences of forest managers (FM) or on the preferences of other stakeholders (OSH). With NM, spruce remained dominant during the simulation period 2010–2100, and the rate of damage significantly increased. Spruce also remained dominant with FM, while the abundance of non-spruce species significantly increased with BAU and OSH. The rate of salvage logging converged at 50% of the total harvest for all MSs up to 2050. Climate change reduced biomass production (?15%) with all MSs but had a negligible effect on biodiversity indicators. The average initial value of the simulated stands was 20,000 € ha?1 and the nominal value in 2100 was between 1900 and 10,900 € ha?1. The Net Present Value calculated with the 2% interest rate was negative during the whole simulation period (?5600 to ?18,500 € ha?1 in 2100). Effect of climate change on all financial indicators was negative. Our findings indicate that secondary spruce forests are highly vulnerable and that the systems proposed by both forest managers and other regional stakeholders failed to significantly reduce forest damage and stabilize forest production. 相似文献
6.
Dušan Gömöry Roman Longauer Tomáš Hlásny Marián Pacalaj Slavomír Strmeň Diana Krajmerová 《European Journal of Forest Research》2012,131(2):401-411
Responses of Norway spruce populations to climatic transfer, in terms of growth and survival, were analyzed on the basis of
a provenance experiment derived from the international provenance test IUFRO 1964/1968. The experiment comprises a series
of five trial plots situated at contrasting elevations ranging from 484 to 1,275 m a.s.l., with 11 provenances represented
at all trial plots that were used for the analysis. Transfer rates were defined as differences in altitudes or climatic variables
between the site of plantation and the site of origin. Optimal transfer rates and optimal climates for individual provenances
were derived from quadratic response functions. Spruce provenances generally responded positively by height and volume growth
to transfer into lower altitudes, i.e., warmer conditions with less precipitations. The analysis at the level of provenances
showed that optimal transfer rates were consistently negatively correlated with the underlying environmental variables and
optimal climates were consequently nearly the same for all provenances irrespective of the response traits and ecodistance
variables. Stability indices based on joint regression analysis indicate that provenances from higher altitudes, colder and
wetter climates tend to be more stable, whereas provenances from lower altitudes, drier and warmer sites are more responsive
to site quality. However, the differences in the stability are small and stability indices were generally close to 1. The
results indicate that populations in different climates remain adapted to a common optimum and the extent of local adaptation
is quite limited. Possible explanations of this observation are briefly discussed. 相似文献
7.
Beat‐to‐beat variation of heart rate is reflective of autonomic balance and has been used to assess pain and stress in human beings. The purpose of this investigation was to pharmacologically manipulate the autonomic nervous system and to determine the effect of these manipulations on heart rate variability (HRV) in dogs. Four adult male hound dogs (27 ± 1 kg) were used in the investigation. Each dog was given five treatments: Parasympathetic blockade (glycopyrrolate; 0.01 mg kg–1 IV and 0.01 mg kg–1 IM), parasympathetic stimulation (phenylephrine; 0.005 mg kg–1 IV + 0.05 mg kg–1hour–1), sympathetic blockade (propranolol; 0.11 mg kg–1 IV), sympathetic stimulation propranolol; 0.01 μg kg–1 minute–1), and saline control. At least 48 hours were allowed between treatments. ECG recordings were obtained using an ambulatory ECG monitor. A 5‐minutes period of continuous recording obtained ~30 minutes after initiation of drug administration was used for data analysis. Changes in HRV were evaluated by time and frequency‐domain analysis. The standard deviation of normal R‐R intervals (SDNN), as well as the standard deviation of successive differences in RR intervals (SDSD) were assessed for each treatment. Low frequency (LFP; 0.05–0.15 Hz), high frequency (HFP; 0.15–0.35 Hz), and total (TP; 0.017–0.5 Hz) spectral power were also determined. The LFP:HFP ratio was also evaluated. A two‐way anova with a Tukey's test was used to detect differences (p < 0.05). Administration of glycopyrrolate or isoproterenol increased HR and decreased SDNN and SDSD below control levels. Phenylephrine or propranolol administration were without effect. LFP was diminished by glycopyrrolate and isoproterenol, but was unaffected by phenylephrine and propranolol. HFP, TP, and LFP:HFP were unaffected by treatment. Both branches of the autonomic nervous system influence SDNN and LFP. SDSD, in contrast, is altered primarily by parasympathetic activity. Thus, it appears that parasympathetic activity modulates HRV in the resting dog, as either withdrawal of parasympathetic influence or accentuated sympathetic activity led to significant changes in these measures of HRV. Conversely, augmentation of parasympathetic activity or withdrawal of sympathetic tone minimally affected HRV. 相似文献
8.
Heart rate variability (HRV) may be useful for objective assessment of stress and pain in animals. The objective of this study was to describe the effect of anesthesia and surgery on HRV in dogs. We hypothesized that surgery would decrease HRV to a greater degree and for a longer duration than anesthesia alone. Four healthy male dogs (29 ± 2 kg) were instrumented for ambulatory ECG monitoring. Continuous ECG data was obtained for 1 day prior to, and 6 days following anesthesia alone (ANES) or anesthesia plus unilateral stifle arthrotomy (ANSX). The anesthetic protocol included xylazine (0.5 mg kg–1 IM), morphine (0.5 mg kg–1 IM), atropine (0.04 mg kg–1 IM), thiopental (10 mg kg–1 IV) and isoflurane in oxygen. A single dose of morphine (0.5 mg kg–1 IM) was administered at extubation. Time domain analysis of HRV was performed on 5 minutes epochs of artefact‐ and arrhythmia‐free ECG data obtained at 12 noon and 12 midnight on each of the seven experimental days. Mean RR interval, standard deviation of normal R‐R intervals (SDNN), and the standard deviation of successive differences in RR intervals (SDSD) were compared to baseline for ANES and ANSX. Pain scores obtained during the day were also evaluated. Significance was set at p < 0.01. There were no differences between groups for any baseline data. Mean RR interval did not differ from baseline on days 1–6 in ANES or ANSX. SDNN and SDSD values at noon were not different from baseline on days 1–6 in ANES or ANSX. At midnight on days 1 and 2, SDNN was significantly decreased from baseline in ANSX, and on day 1 a significant difference between groups existed. ANSX values of SDSD at midnight were significantly decreased from baseline and ANES on day 1. Pain scores for ANSX were significantly greater than baseline on days 1–3, and different from ANES on days 1–5. These results suggest that HRV is decreased following anesthesia plus surgery, and that changes in HRV may be associated with pain. 相似文献
9.
Objective To evaluate the effect of intra‐articular (IA) lidocaine plus bupivacaine on post‐operative pain in sheep undergoing stifle arthrotomy. Study design Randomized controlled experimental trial. Animals Sixteen adult Rambouillet‐cross ewes. Methods Sheep were randomly assigned to one of two treatment groups. The lidocaine/bupivacaine group (L/B, n = 8) received IA lidocaine (40 mg (2 mL)) prior to incision and IA bupivacaine (10 mg (2 mL)) post‐closure, while the control group (n = 8) received no IA injections. IA local anesthetics were an addition to the standard analgesic protocol of phenylbutazone (1 g orally, every 24 hours for 5 days) and transdermal fentanyl (equivalent to 15 mg), initiated 24 hours prior to surgery. A stifle arthrotomy was performed with the purpose of creating a full‐thickness articular cartilage defect. Two observers blinded to treatment assessed sheep for total pain score using a numeric ranking scale that included: comfort, movement, and flock behavior. The first observation (T = 0) was obtained the evening of surgery (3–7 hours post‐operatively); subsequent observations occurred every 12 hours for 72 hours. Nonparametric statistical tests were used to evaluate differences between groups for total pain score. Results L/B sheep had significantly lower total pain scores at T = 0 than control sheep (p < 0.05). No significant differences between treatments were noted at any subsequent time periods. There were no differences attributable to the use of different observers. Conclusions and clinical relevance IA lidocaine plus bupivacaine provided analgesia at 3–7 hours post‐operatively. Use of IA lidocaine and bupivacaine is a simple, effective, yet inexpensive perioperative analgesic protocol for joint surgery in sheep. 相似文献
10.
Heidi L Shafford DVM Peter W Hellyer DVM MS Dipl ACVA Kenneth T Crump CVT Ann E Wagner DVM MS Dipl ACVA Khursheed R Mama DVM MS Dipl ACVA & James S Gaynor DVM MS Dipl ACVA 《Veterinary anaesthesia and analgesia》2002,29(1):43-48
Objective To determine if pulsed electromagnetic field (PEMF) therapy reduces post‐operative pain in dogs following ovariohysterectomy, and to evaluate PEMF interaction with post‐operative morphine analgesia. Study design Randomized controlled clinical trail. Animals Sixteen healthy dogs weighing 18 (10–32) kg [median (range)] and aged 13 (3–36) months. Materials and methods Anesthesia consisted of atropine (0.04 mg kg?1, SC), acepromazine (0.02 mg kg?1, SC), fentanyl (0.01 mg kg?1, SC), thiopental (10–15 mg kg?1, IV) and halothane in oxygen. Ovariohysterectomies were performed by senior veterinary students. Pain score (numeric rating scale, 0–28), pulse rate, respiratory rate, indirect mean arterial pressure (MAP), and body temperature were evaluated prior to anesthetic premedication, at extubation, 30 minutes after extubation, and then hourly for 6 hours. Following extubation, dogs were randomly divided into four groups: a control group that received 0.9% NaCl, IV, and no PEMF; a magnet group that received 0.9% NaCl, IV, and PEMF; a morphine group that received morphine 0.25 mg kg?1, IV, and no PEMF; and, a magnet/morphine group that received morphine 0.25 mg kg?1, IV, and PEMF. A single observer, blinded to treatment, obtained all behavioral observations and physiologic data. Data were analyzed using the Kruskal–Wallis statistical test with a significance of p < 0.05. Results Significant differences in MAP (mm Hg) [median (range)] occurred at 300 minutes [morphine 108 (83–114) and magnet/morphine 90 (83–97) < magnet 135 (113–117)], and at 360 minutes [magnet/morphine 93 (81–100) < control 127 (111–129) and magnet 126 (111–129)]. At 30 minutes the total pain score for the magnet/morphine group [1.5 (0–5)] was significantly less than control [8 (6–13)], but not different from magnet [5.5 (4–7)] or morphine [4.5 (2–9)]. Conclusions and clinical relevance Although no clear benefit was seen in this study, the results suggest that PEMF may augment morphine analgesia following ovariohysterectomy in dogs, and that further study of the analgesic effects of PEMF is warranted. 相似文献