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1.
This paper presents data from 48 resightings of 16 southern right whales that were satellite‐tagged on the South African coast in September 2001, up to and including 2012. Tag performance in terms of number of days with locations received was significantly higher in males than females, and lowest in cows with calves, and attributed to behavioral differences leading to variable degrees of antenna damage. Resightings occurred from 4 to 4,054 d after tagging: tags were retained in all whales seen within 27 mo, but were apparently shed in all but one individual seen within 36 mo of tagging. The exception was a whale that still had the tag present 11 yr after tagging. Healing at the tag site occurred gradually and within 5 yr of tagging (and 2 yr after tag shedding). No significant difference in the subsequent frequency of calving was detected between 12 tagged and 382 untagged females photographed contemporaneously, and although statistical power was low, a 21% or greater reduction in calving rate in tagged females would seem incompatible with the observations. The death of one female 3 yr after tagging was more likely attributable to a ship strike on an animal debilitated by a prolapsed uterus.  相似文献   

2.
One-third of beef calves fail to achieve adequate transfer of passive immunity (TPI) through timely ingestion of colostrum, which substantially increases their risk of preweaning morbidity and mortality. Two randomized clinical trials were designed to assess the impact of volume, immunoglobulin G (IgG) concentration, and feeding method of colostrum product on neonatal nursing behavior and TPI. In Trial 1, 47 calves were randomly assigned to receive one of three colostrum interventions by oro-esophageal tube feeder (OET): 1 L with 100 g/L IgG, 1.4 L with 70 g/L IgG, or 2 L with 100 g/L IgG. In Trial 2, 29 calves were randomly assigned to be fed 1 L of colostrum product with 100 g/L IgG by either nipple bottle (NB) or OET. Colostrum intervention (i.e. feeding of colostrum product) occurred within 60 minutes of birth. Cow-calf pairs were monitored by video surveillance in individual stalls for 24 h. Dam colostrum was collected at 10 minutes and calf serum was collected at 24–36 h after birth to assess IgG concentration. Differences among colostrum intervention groups on latency to stand and nurse were analyzed using Kaplan-Meier survival curves and Cox proportional hazard models. The impact of colostrum intervention group on TPI was assessed using multivariable linear regression modeling. In Trial 1, calves fed 1.4 L with 70 g/L IgG by OET nursed from their dams statistically significantly earlier compared to calves fed 1 L with 100 g/L IgG (P = 0.003) and calves fed 2 L with 100 g/L IgG (P = 0.008). Six of the 15 calves in the NB group in Trial 2 refused to consume part of the colostrum feeding offered by bottle and required follow-up tube feeding of the remaining volume. These calves were analyzed as a separate group (NB + OET). Calves fed 1 L by NB stood and nursed statistically significantly earlier than calves fed by OET (P = 0.005) or a combination of NB + OET (P = 0.003). Calf serum IgG concentrations were not statistically significantly different among colostrum intervention groups (P > 0.1). Overall, the colostrum interventions assessed in this study led to only one calf with failed TPI. While statistically significant differences in serum IgG concentrations were not detected in this study, subsequent nursing behavior did vary and was improved by feeding a moderate volume (1.4 L with 70 g/L IgG) of colostrum when using an OET, and by using the NB when feeding a smaller volume (1 L with 100 g/L IgG).  相似文献   

3.
The Tagging/Retagging model of short term memory was introduced earlier (Tarnow in Cogn Neurodyn 2(4):347–353, 2008) to explain the linear relationship between response time and correct response probability for word recall and recognition: At the initial stimulus presentation the words displayed tag the corresponding long term memory locations. The tagging process is linear in time and takes about one second to reach a tagging level of 100%. After stimulus presentation the tagging level decays logarithmically with time to 50% after 14 s and to 20% after 220 s. If a probe word is reintroduced the tagging level has to return to 100% for the word to be properly identified, which leads to a delay in response time. This delay is proportional to the tagging loss. The tagging level is directly related to the probability of correct word recall and recognition. Evidence presented suggests that the tagging level is the level of depletion of the Readily Releasable Pool (RRP) of neurotransmitter vesicles at presynaptic terminals. The evidence includes the initial linear relationship between tagging level and time as well as the subsequent logarithmic decay of the tagging level. The activation of a short term memory may thus be the depletion of RRP (exocytosis) and short term memory decay may be the ensuing recycling of the neurotransmitter vesicles (endocytosis). The pattern of depleted presynaptic terminals corresponds to the long term memory trace.
Eugen TarnowEmail:
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4.
Bovine respiratory disease is the leading user of antibiotics (AB) in calf production. Mycoplasma (M.) bovis could lead to greater use of AB as it is a persistent and AB resistant causative agent for respiratory diseases. Two cross-sectional studies were set up to assess the effects of lot size and feeding system on M. bovis infection and the effects of M. bovis seroconversion, lot size and feeding system on AB use in calves’ feedlots. Twenty-six lots in 22 fattening farms were monitored for 41–81 days, from all-in entry of calves until three consecutive weeks without using any collective antibiotics. M. bovis spread was estimated by measuring seroconversion at entry and at the end of study period in 10–15 calves randomly sampled in each lot. All AB treatments used in the meanwhile were recorded. The lots were selected according to feeding system, i.e. individual bucket (n = 7) vs. automated milk feeder (AMF, n = 19), and lot size (30–519 calves), less than 50 calves (n = 9) vs. more than 50 calves (n = 17). Statistical analysis was performed using multivariable generalised linear models with fattening farms as random effect. M. bovis spread increased with lot size (odds ratio (OR) 2.9[1.4; 5.8] per two-fold increase in lot size). This proportion of seroconverted calves was lower in bucket-fed lots compared to lots fed with the AMF using a shared nipple (OR = 0.03[0.003; 0.41]). The main risk factor for AB use was the lot size, with an increase of 1.5[0.94; 1.98] treatments per two-fold increase in lot size. For same size lots, the use of bucket can decrease AB consumption by up to 1.03[−2.18; 0.14] treatments per calf compared to AMF. Analysis of the association between seroconversion to M. bovis and AB use was inconclusive. We found that bucket feeding in small-size lots, i.e. up to a maximum of 50 calves in the same space, limits seroconversion to M. bovis and enables lower use of AB in veal calf production.  相似文献   

5.
The purpose of this study was to mark endangered sterlet (Acipenser ruthenus) with visible implant elastomer (VIE) in order to assess mortality, compatibility, retention, persistence and histological reactions resulting from this tagging technique. It was hypothesized there would be only minor effects on the fishes' health, and assumed that acute effects would be more pronounced than long‐term effects. On 11 September 2013, 20 specimens were tagged ventrally with visible implant elastomer, 20 received a subcutaneous injection with 0.9% NaCl solution, and another 20 served as untreated control. Mean total length was 28.0 ± 1.8 cm and mean body mass 64.1 ± 12.0 g. The sterlets were kept in four 4,000‐L tanks filled with 2,400‐L water. Acute effects were monitored for 95 days, where fish were held at temperatures between 2.4°C and 15.2°C, reflecting outdoor conditions. Chronic effects were examined 282 days post‐tagging through histological sections of the tagging region in five sterlets. During the first 95 days of observation, tag retention was 100%. No signs of incompatibility were detected. Body mass did not significantly differ between VIE‐tagged fish and controls. At day 282 post‐tagging, however, distinct tissue reactions were visible at the tagging sites of nine fish. Histological examination of five fish revealed a variable degree of infiltration with leukocytes in the areas around the elastomer, which did not necessarily correspond with the externally visible degree of inflammation. After medical treatment, the lesions healed without complications, whereas the retention rate of the VIE tags was 5%. According to the findings, the tag location rather than the tag itself was responsible for the externally visible irritations, indicating that the ventral subcutis of sterlet is not a suitable site, even for small VIE tags in long‐term studies. The results of this study also suggest that VIE marking should in general be critically evaluated before application in field studies.  相似文献   

6.
During early lactation, most dairy cows experience negative energy balance (NEB). Failure to cope with this NEB, however, can place cows at greater risk of developing metabolic disease. Our objective was to characterise, retrospectively, lying behaviour and activity of grazing dairy cows grouped according to blood non-esterified fatty acids (NEFAs) and β-hydroxybutyrate (BHB) as indicators of postpartum metabolic state. Blood was sampled weekly for up to 4 weeks precalving, on the day of calving (day 0), daily between 1 and 4 days postcalving, and then at least weekly between week 1 and week 5 postcalving for analysis of plasma NEFAs and BHB concentrations. Two hundred and forty-four multiparous Holstein-Friesian and Holstein-Friesian × Jersey cows were classified into one of three metabolic status groups based on maximum blood NEFAs and BHB concentrations during week 1 and 2 postcalving. A cow was classified as having either: (1) low NEFAs and low BHB (Lo–Lo; n = 78), when all blood samples were <1.0 mmol/L for NEFAs and ≤1.0 mmol/L for BHB during the first 2 weeks postcalving; (2) high NEFAs and low BHB (Hi–Lo; n = 134), when blood NEFAs were ≥1.0 mmol/L and blood BHB was ≤1.0 mmol/L at the same sampling time point during the first 2 weeks postcalving; or (3) high NEFAs and high BHB (Hi–Hi; n = 32), when blood NEFAs were ≥1.0 mmol/L and blood BHB was ≥1.2 mmol/L at the same sampling time point during the first 2 weeks postcalving. Accelerometers (IceTag or IceQube devices; IceRobotics Ltd.) were used to monitor lying and activity behaviours peripartum (–21 to +35 days relative to calving). Changes in lying behaviour and activity occurred before the mean day that cows were classified Hi–Hi and Hi–Lo (2.2 and 3.5 d postcalving, respectively). Up to 3 weeks preceding calving, Hi–Hi cows were more active, had fewer daily lying bouts (LBs), and spent less time lying than Lo–Lo cows. In addition, Hi–Hi cows had fewer daily LBs and were less active up to 4 weeks postcalving than Lo–Lo cows, but these differences were biologically small. Groups of grazing cows classified as experiencing a more severe metabolic challenge behave differently up to 3 weeks precalving than their herdmates with lower blood NEFAs and BHB postcalving. These altered behaviours may allow identification of individual cows at risk of a metabolic challenge, but further research is required.  相似文献   

7.
Malus sieversii is a progenitor species of domestic apple M. × domestica. Using population “GMAL 4595” of 188 individuals derived from a cross of Royal Gala × PI 613988 (apple scab resistant, M. sieversii), 287 SSR (simple sequence repeats) loci were mapped. Of these SSRs, 80 are published anchors and 207 are newly developed EST (expressed sequence tag) contig-based SSRs, representing 1,630 Malus EST accessions in GenBank. Putative gene functions of these EST contigs are diverse, including regulating plant growth, development and response to environmental stresses. Among the 80 published SSRs, 18 are PI 613988 specific, 38 are common and 24 are Royal Gala specific. Out of the 207 newly developed EST contig-based SSRs, 79 are PI 613988 specific, 45 are common and 83 are Royal Gala specific. These results led to the construction of a M. sieversii map (1,387.0 cM) of 180 SSR markers and a Royal Gala map (1,283.4 cM) of 190 SSR markers. Mapping of scab resistance was independently conducted in two subsets of population “GMAL 4595” that were inoculated with Ventura inaequalis races (1) and (2), respectively. In combination with the two major resistance reactions Chl (chlorotic lesions) and SN (stellate necrosis) to each race, four subsets of resistance data, i.e., Chl/race (1), SN/race (1), Chl/race (2) and SN/race (2), were constituted and analyzed, leading to four resistance loci mapped to the linkage group 2 of PI 613988; SNR1 (stellate necrosis resistance to race (1)) and SNR2 are tightly linked in a region of known scab resistance genes, and ChlR1 (Chlorotic lesion resistance to race (1)) and ChlR2 are also linked tightly but in a region without known scab resistance genes. The utility of the two linkage maps, the new EST contig-based markers and M. sieversii as sources of apple scab resistance are discussed.  相似文献   

8.
Poor performance and ill-health of calves in the pre-wean period can affect future productivity. Increasing numbers of producers are opting to use calf jackets as a means of mitigating the potential negative effects of low ambient temperatures, wind speed and precipitation on growth and health. This study aimed to use a range of noninvasive monitoring technologies to investigate the effects of using calf jackets in the first 3 weeks of life on calf performance and behavioural and physiological parameters. Ninety Holstein-Friesian calves were allocated to one of the two treatments: (i) Jacketed until 21 days of age and (J; n = 44) ii. Nonjacketed (NJ; n = 46). Calves were group housed and fed milk replacer (MR) and concentrate solid feed via automatic feeders. Calves were weaned at day 56, and the experiment was completed at day 63. Health assessments were conducted on a daily basis throughout the experiment using predefined faecal and respiratory scoring protocols. A range of novel, noninvasive monitoring technologies were used to examine the activity, heart rate and thermal profiles of calves on an individual basis throughout the experimental period. There were no differences in calf live weight (LWT), average daily gain (ADG) or feed conversion efficiency (FCE) in J and NJ calves between days 5 to 20. However, NJ calves consumed more MR and had more unrewarded visits to the milk feeder than J calves during this period. Although calf LWT was comparable across treatments in the week following jacket removal (days 21 to 28), both ADG and FCE tended to be greater in NJ calves. There were no treatment differences in calf LWT at the end of the study (d63). When measured over a period of 24 h and at a mean ambient temperature of 7.7°C, skin surface temperature was 6.37°C higher in J calves. Core body temperature was higher in J calves between days 5 to 20; however, there were no differences in IR eye or IR rectal temperature. No differences in lying behaviour occurred, with calves spending 18 and 17 h/day lying between days 5 to 20 and days 21 to 28, respectively. Under the climatic and management conditions described, no significant benefits to calf performance were found as a result of the provision of calf jackets to group-housed calves in the first 3 weeks of life. The higher frequency of unrewarded visits to the milk feeder in NJ calves during the first 3 weeks of life could be suggestive of a lack of satiety in these calves.  相似文献   

9.
Management of Pacific halibut (Hippoglossus stenolepis), a long-lived flatfish, is complicated by possible ontogenic and sex-specific variation in migration. Archival tags promise the ability to help uncover long-term movement patterns at the individual level, if the tags can be retained and recovered from healthy fish. We examined fifteen individuals (69–90 cm fork length) for long-term physiological response to intracoelomic implantation of three types of archival tags: fully internal, internal with right angle protruding light stalk, and internal with straight protruding light stalk. Tags represented 0.05–0.16% of initial fish weights. Fish were reared at 10.8 ± 1.1°C for 59 weeks post-surgery. One fish died after 39 weeks from thermal stress unrelated to the surgical procedure. Temporal variation in behavior of tagged fish was indistinguishable from that of controls (n = 15 tagged, 5 controls). Treatment and control-group fish grew at similar rates. No tag expulsion or physiological response was evident in the individual that died at 39 weeks, but nine of eleven individuals dissected at the end of 59 weeks had developed internal responses. These responses ranged from deposition of fibrous protein and/or calcitic material on tag surfaces to partial or full tag encapsulation in either the visceral peritoneal layer (fully-internal tags) or the intestinal mesenteries (stalk-bearing tags). The responses were within the range reported for other pleuronectids implanted with tags of similar configuration and may have implications for design and interpretation of long-term tagging studies. Encapsulation may reduce the probability of tag recoveries even in the absence of tag expulsion, especially in species eviscerated at sea.  相似文献   

10.
Infrared thermography was used to monitor the healing process at flipper tag sites in gray seal (Halichoerus grypus) pups. We tested the hypothesis that tagging would result in a rise in surface temperature associated with tag site healing processes compared with adjacent untagged areas of the flipper. Prior to tagging thermal images were recorded of the dorsal side of hind flippers of pups tagged in early lactation (n= 20) and at weaning (n= 19) on the Isle of May, Scotland (56°11′N, 02°33′W) from October to December 2008. Pups tagged in early lactation were sampled again at late lactation, at weaning and then every 3 d for an average of 29 d post‐tagging while pups tagged at weaning were sampled every 3 d for an average of 17 d post‐tagging. Tag sites were also scored for signs of infection or swelling at each sampling. Results showed that (1) small temperature increases associated with wound healing processes around the tag site returned to pre‐tagging levels before animals leave the island and (2) there was little evidence of tagging‐related infections or tag loss irrespective of age at tagging.  相似文献   

11.
We validated the effects of a passive integrated transponder (PIT) tagging process on the oriental weather loach Misgurnus anguillicaudatus. Laboratory experiments were conducted to assess the effects of PIT tagging on fish survival, growth, wound healing, and tag omission. Two tagging protocols, standard syringe injection versus insertion through a small hole pierced by a fine needle-shaped awl, were compared using a 12.5 × 2.07 mm2 tag. A control group was also included. In comparison with the awl technique, syringe injection heightened the mortality of the loach and delayed healing of the wound caused by tag insertion. No effects of either PIT tagging method were detected on the growth of surviving loach. We also field-tested similarly tagged populations within a river-based irrigation system of Sado Island, Japan. Two different sized tags (long, 12.5 × 2.07 mm2; short, 8.5 × 2.12 mm2) were compared by using antenna loggers which detected fish movement through gates and automatically logged tagged fish’s tag IDs and timestamps. By comparing logged data and actual fish collection surveys both below and above the gates, 77% and 30% of actual loach movements were confirmed to have been successfully logged for the long and short tags, respectively. The awl insertion technique with the longer tag is therefore recommended for use in similar studies of smaller fish species.  相似文献   

12.
Sea stars are important marine predators, and their feeding often controls the distribution of associated species. Therefore, quantifying their activity at an individual level is important in further understanding how they structure marine communities. Sea stars are difficult to tag, so there is little information on activity of sea stars in their natural environment over extended periods of days to weeks. We tagged the New Zealand sea star Coscinasteriasmuricata with small archival electronic tags that recorded water temperate and depth every 5 min for up to 2 weeks. The tagging was undertaken to test the viability of using electronic tags in research on the ecology of the sea stars in a New Zealand fiord, where their vertical distribution is influenced by the presence of low-salinity layers. The effects of the tagging were tested in the laboratory and in the field, with tagging having no detectable influence on invitro survival, feeding rate, and righting time, or on their insitu movement and depth distribution. Laboratory experiments testing the salinity tolerance of C.muricata showed they could tolerate salinities as low as 25 PSU for at least a 20-day period. Tagging of sea stars in their natural environment provided information on depth distributions, vertical migrations and the influence of the physical environment on their behaviour. The tagging also revealed a large variation in activity at the individual level. This study represents one of the first to utilise electronic tagging to study the ecology of a mobile invertebrate such as a sea star. The success of this initial study suggests that we could gain valuable quantitative insight into the ecology of these animals in future tag deployments.  相似文献   

13.
A 95‐day experiment was conducted to evaluate the performance of a visible implant elastomer tag (VIE) versus a coded wire tag (CWT) implanted in juvenile Tibet fish Oxygymnocypris stewartii (Lloyd, 1908; total length 5~7 cm) under laboratory conditions. Mortality, tag retention and growth in three groups of juvenile O. stewartii (VIE‐tagged, CWT‐tagged and control) in duplicate were determined in six indoor tanks (300‐L/tank volume, 100 fish/tank) at 15.6 ± 0.5°C water temperature. Results showed that neither tagging method had a significant difference on the mortality of the experimental fish, but that the growth rate in the VIE group was significantly lower than in the CWT and control groups. Mean tag retention in the VIE group was 95.2%, and 98.9% in the CWT group, with no significant differences in tag retention in the two methods. The study indicates that both VIE and CWT are suitable short‐term tagging methods for hatchery O. stewartii juveniles.  相似文献   

14.
Dairy calves may benefit from extending the duration of feeding transition milk (TM; the subsequent two to six milkings after parturition) to enhance performance and health during early life. The objective of this study was to assess the effect of replacing pasteurized waste milk (non-saleable milk containing antibiotic and/or drug residues) with pasteurized TM for 3 weeks on the growth performance and health of dairy calves. A total of 84 healthy newborn female Holstein calves were blocked by birth order and assigned randomly to 4 treatment groups with partial replacement of pasteurized waste milk by TM (second milkings after parturition) at 0 (0 l/day TM + 6 l/day milk), 0.5 (0.5 l/day TM + 5.5 l/day milk), 1 (1 l/day TM + 5 l/day milk), or 2 l (2 l/day TM + 4 l/day milk) for a 21-day period. From day 22 onward, all calves were fed individually with 6 l/day pasteurized waste milk. Calves were weaned on day 60 and monitored until day 90 of the study. Liquid feed DM intake (DMI) was increased with increasing levels of TM (P = 0.001). Starter feed DMI and total DMI (liquid feed DMI + starter feed DMI) were not affected by the treatment effect. Calves were fed 2 l/day TM gained more BW compared with those in the control group during the postweaning and overall periods. The average daily gain tended (P = 0.06) to be higher in calves fed 2 l/day TM compared with calves fed 0 (+ 65 g/day), 0.5 (+ 53 g/day), or 1 (+ 76 g/day) l/day TM during the preweaning period. Daily weight gain was also higher in calves fed 2 l/day TM compared with calves in the control group during the postweaning (+ 137 g/day; P = 0.04) and overall (+ 89 g/day; P < 0.01) periods, respectively. Calves fed 2 l/day TM had a higher feed efficiency compared with calves in the control group during all studied periods. The calves fed TM2 had a lower chance of having diarrhea compared with other treatment groups. Duration but not the frequency of diarrhea was lower in calves fed TM2 vs TM0 (2.5 vs 4.2 days; P = 0.03). In general, partial replacement of waste milk with TM (2 l/day) may be recommended to feed dairy calves at an early stage of life to support a higher growth rate and health benefits.  相似文献   

15.
King RR  Calhoun LA 《Phytochemistry》2005,66(20):2468-2473
Four feruloyl amides, N-trans-feruloyloctopamine (1), N-cis-feruloyloctopamine (2), N-trans-feruloyltyramine (3), N-cis-feruloyltyramine (4), a cross-linked N-trans-feruloyltyramine dimer (5), and a cross-linked N-cis-feruloyltyramine dimer (6) were isolated from potato common scab lesions. The compounds were purified by TLC and characterized by a combination of (1)H and (13)C NMR spectroscopic techniques. The presence of an accompanying minor complex of cross-linked dimers containing both feruloyltyramines and feruloyloctopamines was also demonstrated. This is the first characterization of cross-linked hydroxycinnamic acid amides associated with wound healing in potato (Solanum tuberosum) tubers.  相似文献   

16.
The objectives of this experiment were to evaluate the effect of early human contact and of the separation method from the dam on the future relationships of calves with humans, and to investigate the relationship between dam responses and calf responses. Thirty-three Salers calves aged 2–4 days old and reared outdoors were split into 3-week treatments balanced according to sex and birth dates. Group 1 (long separation from the dam and human contact: LS + H; n = 11) underwent 8 h of separation from the dam per day and 5 min of individual stroking; group 2 (short separation from the dam and human contact: SS + H; n = 11) underwent 1 h of separation and the same amount of human contact as LS + H calves. Group 3 (short separation from the dam and no human contact: SS − H; n = 11) was a control group undergoing the same duration of separation as SS + H but without stroking. At 3, 15 and 45 weeks of age, the calves were tested in a standard arena test (AT) where they were successively left alone (2 min), left with a stationary human (5 min), and left with a human approaching and touching them (2 min). At 15 and 45 weeks, the calves were also tested with the standard docility test (DT: test of restraint). The dams were also tested with DT 2 months before calving. Data analysis via Mann–Whitney tests and Spearman's correlations showed no significant effect of the duration calves were separated from their dams. Just after treatment at 3-week of age, calves given stroking (LS + H and SS + H) were more motionless and more willing to accept human contact (AT: touching) than control calves (SS − H, P < 0.01). At 45 weeks of age, calves given stroking spent also significantly more time (P < 0.05) motionless with the approaching human compared to non-stroked calves (SS − H), suggesting a persistent effect. However, this effect was not reproduced on the other behavioural criteria recorded (e.g., duration of human contact or docility score). In the different tests and at the different ages, the docility scores of the dams were significantly correlated (up to 0.7, P < 0.01) with behaviour towards humans shown by stroked calves but not non-stroked calves (SS − H). Our results suggest that additional human contact at early age, but not duration of the separation from the dam, could be beneficial for the human–animal relationship, but only for calves born to docile dams.  相似文献   

17.
Aims:  To test interactions between pathogenic strains of Streptomyces turgidiscabies , S. scabies and S. aureofaciens . To study biological control of S. turgidiscabies and S. scabies using the nonpathogenic Streptomyces strain (346) isolated from a scab lesion and a commercially available biocontrol agent ( S. griseoviridis strain K61; 'Mycostop').
Methods and Results:  Pathogenic strains of S. turgidiscabies and S. aureofaciens inhibited growth of S. scabies in vitro , whereas strain 346 and S. griseoviridis inhibited the pathogenic strains and were subsequently tested for control of scab in the greenhouse and field. Strains 346 and K61 suppressed development of common scab disease caused by S. turgidiscabies in the greenhouse. Strain 346 reduced incidence of S. turgidiscabies in scab lesions on potato tubers in the field.
Conclusions:  Streptomyces turgidiscabies shows antagonism against S. scabies that occurs in the same scab lesions and shares the ecological niche in the field. Biocontrol of S. turgidiscabies is possible with nonpathogenic Streptomyces strains but interactions may be complicated.
Significance and Impact of the Study:  Streptomyces turgidiscabies may have potential to displace S. scabies under the Scandinavian potato growing conditions. Biological control of the severe potato scab pathogen, S. turgidiscabies , is demonstrated for the first time. The results can be applied to enhance control of common scab.  相似文献   

18.
Information on fish movement and growth is primarily obtained through the marking and tracking of individuals with external tags, which are usually affixed to anesthetized individuals at the surface. However, the quantity and quality of data obtained by this method is often limited by small sample sizes owing to the time associated with the tagging process, high rates of tagging‐related mortality, and displacement of tagged individuals from the initial capture location. To address these issues, we describe a technique for applying external streamer and dart tags in situ, which uses SCUBA divers to capture and tag individual fish on the sea floor without the use of anesthetic. We demonstrate this method for Indo‐Pacific lionfish (Pterois volitans/P. miles), species which are particularly vulnerable to barotrauma when transported to and handled at the surface. To test our method, we tagged 161 individuals inhabiting 26 coral reef locations in the Bahamas over a period of 3 years. Our method resulted in no instances of barotrauma, reduced handling and recovery time, and minimal post‐tagging release displacement compared with conventional ex situ tag application. Opportunistic resighting and recapture of tagged individuals reveals that lionfish exhibit highly variable site fidelity, movement patterns, and growth rates on invaded coral reef habitats. In total, 24% of lionfish were resighted between 29 and 188 days after tagging. Of these, 90% were located at the site of capture, while the remaining individuals were resighted between 200 m and 1.1 km from initial site of capture over 29 days later. In situ growth rates ranged between 0.1 and 0.6 mm/day. While individuals tagged with streamer tags posted slower growth rates with increasing size, as expected, there was no relationship between growth rate and fish size for individuals marked with dart tags, potentially because of large effects of tag presence on the activities of small bodied lionfish (i.e., <150 mm), where the tag was up to 7.6% of the lionfish's mass. Our study offers a novel in situ tagging technique that can be used to provide critical information on fish site fidelity, movement patterns, and growth in cases where ex situ tagging is not feasible.  相似文献   

19.
Population augmentation and propagation of pallid sturgeon (Scaphirhynchus albus) have been a focus of scientists since the mid‐1990s. Various tag types have been used to gain a better understanding of population characteristics, stocking success, and movement patterns. Passive integrated transponder (PIT) tags have been consistently used since the inception of recovery efforts to mark age‐1 and older pallid sturgeon. This tag has been successfully used with other sturgeon species, and tagging protocols for pallid sturgeon were developed in response to those successes. Tag retention rates in pallid sturgeon have been reported as variable or unknown and there has been no formal study to determine PIT tag retention in pallid sturgeon, particularly with age‐1 individuals that are propagated in hatcheries to be stocked into the wild. The objective was to evaluate retention rates of PIT tags inserted into the operculum and along the base of the dorsal fin of age‐1 pallid sturgeon (total fork length [FL] range = 214–358 mm). Tagged sturgeon (n = 80) were held in a large holding tank and inspected for tag loss twice a month for a total of 189 days. Final tag retention was 83% for tags inserted into the operculum and 85% for tags inserted near the dorsal fin. Tags shed from the operculum were from smaller fish (mean FL = 265 mm) and losses occurred during the first 60 days of the experiment. Tags shed from the dorsal site were predominantly from larger individuals (mean FL = 305 mm) and losses were continual throughout the experiment. Future research should determine size‐specific tag retention rates so that hatcheries can maximize retention in either tag placement location.  相似文献   

20.
Albino mice were successfully infected intravenously, subcutaneously, intraperitoneally and on the intact and scarified skin with Dermatophilus congolensis. Various gross lesions were observed. Large subcutaneous nodules were produced in mice that were injected subcutaneously. Lesions involving the internal organs were obtained in mice that had been injected intravenously and intraperitoneally in addition to microabsessation and scab formation on the tails of those that were injected intravenously. The application of D. congolensis on scarified skin resulted in scab formation covering the whole area while its application on non-scarified skin produced isolated lesions. The organism was isolated in pure culture from exudate, pus and scab material obtained from lesions. Severe histopathological changes were noted in sections prepared from the lesions. Premedication of mice with prednisolone trimethylacetate increased the severity of the experimentally induced lesions.  相似文献   

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