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871.
Although ordinary chondrite (OC) meteorites dominate observed falls, the identification of near-Earth and main-belt asteroid sources has remained elusive. Telescopic measurements of 35 near-Earth asteroids ( approximately3 kilometers in diameter) revealed six that have visible wavelength spectra similar to laboratory spectra of OC meteorites. Near-Earth asteroids were found to have spectral properties that span the range between the previously separated domains of OC meteorites and the most common (S class) asteroids, suggesting a link. This range of spectral properties could arise through a diversity of mineralogies and regolith particle sizes, as well as through a time-dependent surface weathering process. 相似文献
872.
Clarissa MR. Moreira Renato LS. Oliveira Gilberto A. Costa Katia B. Corgozinho Stelio PL. Luna Heloisa JM. Souza 《Veterinary anaesthesia and analgesia》2021,48(1):134-141
ObjectiveTo evaluate the analgesic efficacy and safety of tumescent local anesthesia (TLA) in cats undergoing unilateral mastectomy.Study designProspective clinical trial.AnimalsA total of 12 ovariohysterectomized female cats.MethodsAll animals were premedicated with pethidine (4 mg kg–1) intramuscularly (IM), followed by induction of anesthesia with propofol (5 mg kg–1) intravenously and maintenance with isoflurane in oxygen. A refrigerated TLA solution (15 mL kg–1, 8 °C) was injected using a Klein cannula. The solution was composed of 0.5 mL of epinephrine (1 mg mL–1) and 40 mL of 2% lidocaine added to 210 mL lactated Ringer’s solution (final lidocaine concentration 0.32%). Heart and respiratory rates, systolic arterial blood pressure, temperature and oxygen saturation were measured during anesthesia. Blood samples were collected from the jugular vein for measurement of plasma lidocaine concentration using high performance liquid chromatography. Postoperative pain scores were evaluated hourly for 6 hours. Analgesic rescue was performed with tramadol (2 mg kg–1) IM and meloxicam (0.15 mg kg–1) subcutaneously.ResultsPlasma lidocaine concentration peaked at 90 minutes after injection of TLA, but no concentration considered toxic for the species was measured. The median postoperative analgesia time was 6 hours after injection of TLA.ConclusionsThis study found that TLA prevented sympathetic response to noxious stimuli during anesthesia and provided satisfactory postoperative analgesia in cats submitted to total unilateral mastectomy, with no apparent signs of toxicity.Clinical relevanceTLA can prevent sympathetic stimulation resulting from noxious stimuli during anesthesia, promoting good intraoperative conditions, proving to be a viable addition to analgesia in cats submitted to a total unilateral mastectomy. 相似文献
873.
Staffan Berg Janine Schweier Franka Brüchert Marcus Lindner Erik Valinger 《Scandinavian Journal of Forest Research》2014,29(5):485-498
The forest sector is important for the German Federal State of Baden-Württemberg (BW) and the Västerbotten (VB) County in Sweden. Their forestry wood chains (FWCs) are of similar magnitude and supply forest industries. This study provides a regional comparison of the performance of FWCs from roundwood harvesting, including hauling, to mill gate concerning the factors that impact sustainability and assess different sustainability indicators for alternative supply chains, in particular fully mechanized chains in comparison to motor-manual operations. The harvest volumes are similar but operational conditions differ. Analysis of sustainability indicators demonstrated that the total costs for roundwood to industry are similar. Higher harvesting costs in BW are compensated for by lower transport costs to the mills. Employment per unit is higher in BW because of the high share of labour in felling. Due to smaller machinery and shorter transport distances in BW, energy use and greenhouse gas emissions per unit are lower than in VB. Areas for improvement are the technologies for logging in BW and the logistics of timber transport in VB. 相似文献
874.
Accumulation of nutrients in the sediment under a tilapia cage farm (2.8–4.4% C, 0.26–0.49% N and 0.04–0.26% P) seemed to follow a seasonal pattern, with highest concentrations prior to winter water turnover. However, in April 1994 (and for P also in April 1992) the surface sediment contained significantly higher nutrient concentrations compared to controls. Generally, significantly higher pore water concentrations were found under the cages compared to controls. However, only in April 1992 were these concentrations of the same magnitude as those found in temperate studies. The average flux of particulate material under the cages, 20–49 g m?2 per day, was up to 22 times greater compared to controls. Carbon accumulated only in April 1994, implying rapid decomposition. This was supported by a 4–25-fold higher outward flux of ammonium and phosphate from the farm sediment but sediment O2 consumption was only 29–40% higher compared to control sites. It was concluded that intensive fish farming in the tropics can generate similar eutrophication effects that are observed in temperate regions. However, the results also indicated that a tropical lake system may be able to process local deposition of organic wastes better than a temperate one, suggesting that microbial decomposition may be a rapid and prominent process. 相似文献
875.
Caipang CM Lazado CC Berg I Brinchmann MF Kiron V 《Fish physiology and biochemistry》2011,37(3):603-612
The present study investigated the immunomodulatory activities of alginic acid and fucoidan, both derived from brown seaweeds,
on selected cellular immune responses and antibacterial activity of head kidney (HK) leukocytes of cod, Gadus morhua. Primary cultures of HK leukocytes were incubated with either 10 or 100 μg ml−1 of the substances and the effects on respiratory burst, cellular proliferation, acid and alkaline phosphatase activity and
cellular myeloperoxidase were measured at 3- and 24-h post-incubation. The antibacterial activity of the supernatants collected
from the cell cultures incubated with 100 μg ml−1 of the substances were tested against Vibrio anguillarum and Aeromonas salmonicida. Respiratory burst was significantly elevated in cells incubated with either alginic acid or fucoidan in a dose-dependent
manner. Incubation with a higher dose of alginic acid and fucoidan resulted in lower cellular proliferation at 3- and 24-h,
respectively. Both acid and alkaline phosphatase activities of HK leukocytes were not significantly modulated, except for
a slight elevation of acid phosphatase in cells incubated with 100 μg ml−1 of alginic acid for 24-h. Fucoidan, but not alginic acid significantly increased cellular myeloperoxidase activity at a concentration
of 100 μg ml−1. The growth of the bacteria in both the treated and control supernatants was significantly lower than what was observed in
the bacterial culture medium. However, the supernatants from the treated cells had significantly higher bacterial growth compared
with supernatants of the control cells. Taken together, these results showed that at the tested concentrations, both alginic
acid and fucoidan are able to differentially stimulate some cellular immune responses of cod HK leukocytes in vitro and the
respiratory burst activity was significantly stimulated by these brown algal derivatives. These substances could be tested
as potential immunostimulants in future in vivo studies. 相似文献
876.
Nguyen Thanh Trung Jan Berg Vu Chi Cuong Nils Petter Kjos 《Tropical animal health and production》2014,46(6):925-930
The objective of this study was to evaluate the effect of supplementation of varying levels of cassava root meal (CRM, 300 and 1,000 g), without or with 700 g groundnut cake (GNC) on intake and performance of growing Laisind cattle fed with a basal diet of urea-treated rice straw (URTRS). Twenty-four male cattle of crossbred Laisind (50 % Red Sindhi and 50 % local Yellow, both Bos indicus), from 15 to 17 months of age, 165–175 kg body weight, were used. They were assigned to a completely randomized block design in a 2?×?2 factorial arrangement (two CRM levels and two GNC levels). Intake of URTRS (interaction, P?<?0.01) and digestibility of neutral detergent fiber (interaction, P?<?0.05) decreased as CRM level increased on the diets without GNC but was not affected by CRM level on the diets with GNC. The total dry matter intake (interaction, P?<?0.05) and live weight gain (LWG) (interaction, P?<?0.001) increased as CRM level increased on the diets with GNC, but no difference was observed on the diets without GNC. In conclusion, supplementation of 1,000 g CRM should be in combination with 700 g GNC to avoid the negative effects on URTRS intake and digestibility, therefore improving LWG of growing Laisind cattle fed on a URTRS-based diet. 相似文献
877.
?ystein Wessel Finstad Maria Krudtaa Dahle Tone H?g Lindholm Ingvild Berg Nyman Marie L?voll Christian Wallace Christel Mor?us Olsen Anne K Storset Espen Rimstad 《Veterinary research》2014,45(1):35
Piscine orthoreovirus (PRV) belongs to the Reoviridae family and is the only known fish virus related to the Orthoreovirus genus. The virus is the causative agent of heart and skeletal muscle inflammation (HSMI), an emerging disease in farmed Atlantic salmon (Salmo salar L.). PRV is ubiquitous in farmed Atlantic salmon and high loads of PRV in the heart are consistent findings in HSMI. The mechanism by which PRV infection causes disease remains largely unknown. In this study we investigated the presence of PRV in blood and erythrocytes using an experimental cohabitation challenge model. We found that in the early phases of infection, the PRV loads in blood were significantly higher than in any other organ. Most virus was found in the erythrocyte fraction, and in individual fish more than 50% of erythrocytes were PRV-positive, as determined by flow cytometry. PRV was condensed into large cytoplasmic inclusions resembling viral factories, as demonstrated by immunofluorescence and confocal microscopy. By electron microscopy we showed that these inclusions contained reovirus-like particles. The PRV particles and inclusions also had a striking resemblance to previously reported viral inclusions described as Erythrocytic inclusion body syndrome (EIBS). We conclude that the erythrocyte is a major target cell for PRV infection. These findings provide new information about HSMI pathogenesis, and show that PRV is an important factor of viral erythrocytic inclusions. 相似文献
878.
R Kasimanickam M Asay S Schroeder V Kasimanickam JM Gay JP Kastelic JB Hall WD Whittier 《Reproduction in domestic animals》2014,49(6):1063-1067
Profitability of a beef operation is determined by the proportion of cows attaining pregnancy early in the breeding season and those that are pregnant at the end of breeding season. Many factors, including temperament, contribute to those reproductive parameters. The objective of this study was to evaluate effects of temperament on reproductive performance of beef cows. In Experiment 1, Angus and Angus‐cross beef cows (n = 1546) from eight locations were assigned a body condition score (BCS; 1 = emaciated; 9 = obese) and chute exit and gait score (1 = slow exit, walk; calm temperament; 2 = jump, trot or run; excitable temperament). Cows were grouped with bulls (1 : 25 to 1 : 30; with satisfactory breeding potential and free of venereal disease) for an 85‐day breeding season. Pregnancy status and stage of gestation were determined (transrectal palpation) 35 days after the end of the breeding season. Controlling for BCS (p < 0.01) and handling facility (p < 0.0001) and handling facility by temperament score interaction (p < 0.001), breeding season pregnancy rate was lower in excited versus calm cows [88.6% (798/901) vs 94.1% (607/645); p < 0.001]. Cows with an excitable temperament took 24 more days to become pregnant compared to calm cows (median days to pregnancy, 35 vs 59 days; p < 0.0001). In Experiment 2, Angus and Angus‐cross beef cows (n = 1407) from 8 locations were assigned scores for body condition and chute exit and gait (as described in Experiment 1) and assigned to bulls (breeding sound and free of venereal disease; 1 : 25 to 1 : 30) for 85 days. Pregnancy status was determined by transrectal palpation at 2 and 6 months after the onset of the breeding season. Controlling for BCS (p < 0.05), pregnancy loss was higher in excited versus calm cows [5.5% (36/651) vs 3.2% (20/623), p < 0.0001]. In conclusion, beef cows with an excitable temperament had significantly lower reproductive performance than calmer cows. The modified two‐point chute exit–gait scoring method was repeatable and identified cattle with an excitable temperament. 相似文献
879.
C Rodenas X Lucas T Tarantini D Del Olmo J Roca JM Vazquez EA Martinez I Parrilla 《Reproduction in domestic animals》2014,49(1):115-121
The aim of this study was to evaluate the influence of Hoechst 33342 (H‐42) concentration and of the male donor on the efficiency of sex‐sorting procedure in canine spermatozoa. Semen samples from six dogs (three ejaculates/dog) were diluted to 100 × 106 sperm/ml, split into four aliquots, stained with increasing H‐42 concentrations (5, 7.5, 10 and 12.5 μl, respectively) and sorted by flow cytometry. The rates of non‐viable (FDA+), oriented (OS) and selected spermatozoa (SS), as well as the average sorting rates (SR, sorted spermatozoa/s), were used to determine the sorting efficiency. The effects of the sorting procedure on the quality of sorted spermatozoa were evaluated in terms of total motility (TM), percentage of viable spermatozoa (spermatozoa with membrane and acrosomal integrity) and percentage of spermatozoa with reacted/damaged acrosomes. X‐ and Y‐chromosome‐bearing sperm populations were identified in all of the samples stained with 7.5, 10 and 12.5 μl of H‐42, while these two populations were only identified in 77.5% of samples stained with 5 μl. The values of OS, SS and SR were influenced by the male donor (p < 0.01) but not by the H‐42 concentration used. The quality of sorted sperm samples immediately after sorting was similar to that of fresh samples, while centrifugation resulted in significant reduction (p < 0.05) in TM and in the percentage of viable spermatozoa and a significant increase (p < 0.01) in the percentage of spermatozoa with damage/reacted acrosomes. In conclusion, the sex‐sorting of canine spermatozoa by flow cytometry can be performed successfully using H‐42 concentrations between 7.5 and 12.5 μl. The efficiency of the sorting procedure varies based on the dog from which the sperm sample derives. 相似文献
880.
Tobias K. Mildenberger Casper W. Berg Alexandros Kokkalis Adrian R. Hordyk Chantel Wetzel Nis S. Jacobsen Andr E. Punt J. Rasmus Nielsen 《Fish and Fisheries》2022,23(1):73-92
The precautionary approach to fisheries management advocates for risk-averse management strategies that include biological reference points and account for scientific uncertainty (i.e. process, model and observation uncertainty). In this regard, two approaches have been recommended: (a) biomass reference points to safeguard against low stock biomass, and (b) uncertainty buffers that reduce the catch limit as a function of the scientific uncertainty. This study compares the effectiveness of these two precautionary approaches in recovering over-exploited fish stocks. We evaluate the performance of more than 80 harvest control rules (HCRs) within a stochastic management strategy evaluation (MSE) framework for three stocks with contrasting life-history parameters and under various levels of scientific uncertainty. The results show that both approaches reduce the risk of overfishing at the expense of expected yield. This risk-yield trade-off strongly depends on the HCRs, life-history parameters of the species, as well as the level of the scientific uncertainty. Nevertheless, some combinations of biomass threshold and limit reference points as well as uncertainty buffers lead to a more favourable risk-yield trade-off than other rules. This study elucidates the multiple factors affecting the effectiveness of management strategies and highlights key features of HCRs for precautionary fisheries management. 相似文献