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101.
BACKGROUND: The crayfish Procambarus clarkii inflicts severe ecological and economic damages in Europe. To develop an efficient method for its control, four experiments were carried out to assess the impact of natural pyrethrum (i.e. Pyblast) on crayfish: (1) the 24 h LC100 and LC50 were quantified on crayfish; (2) the breakdown time of the 24 h LC100 was assessed using Daphnia magna as a bioindicator; the effects of 24 h LC100 on crayfish were investigated by applying the biocide into burrows (3) and in a drainage channel (4). RESULTS: Pyblast concentrations of 0.05 and 0.02 mg L?1 corresponded to 24 h LC100 and LC50 respectively. The concentration of 0.05 mg L?1 broke down after 72 h, whereas 0.02 mg L?1 did not cause any significant mortality in D. magna after 24 h. However, 0.05 mg L?1 had no effect on crayfish when introduced into the burrows, but led to a mortality of 95% when applied in the water. CONCLUSION: Experimental evidence is provided for the efficacy of Pyblast to control invasive crayfish. Obviously, before its use on a large scale, further studies are needed to find a concentration that will achieve the target 100% mortality with the shortest recovery time of the environment. Copyright © 2012 Society of Chemical Industry  相似文献   
102.
Since virulence ofFusarium oxysporum f.sp.vasinfectum (FOV) on cotton (Gossypium hirsutum) is enhanced when the fungus is cultivated in a saline environment, excessively saline water must not be used for the irrigation of cotton. However, the limitations thus placed on the available water resources may lead to conditions of enforced water stress for the plant. The present study investigated whether water stress affects the susceptibility of cotton to FOV. Groups of 2-month-old cotton plants of theFusarium-susceptible Coker 304 and the moderately resistant GSC 20 varieties were maintained without watering for varying periods immediately before or after being inoculated with FOV (15 plants per group, two replications). Watering was suspended for 3, 6, 12 or 24 days before inoculation, and for 3, 6, 12 or 15 days after inoculation. After inoculation the plants were maintained in a controlled environment with a 15,000 lux, 12-h photoperiod, at 28°/24°C D/N, 20% r.h. Xylem water potential was determined in a pressure chamber. Percent infected leaf area and date of onset of wilt were the parameters used to define severity of FOV infection. There was a consistent relation between low water potential in the xylem (-7 and -20 MPa) and severity of infection, particularly when the dry period occurred after inoculation. After exposure to the lowest post-inoculation water potentials, even variety GSC 20, which is normally moderately resistant, exhibited a fairly high percent infected leaf area. This should be taken into account when the cotton grower is faced with water shortages, especially during the period from branching to flower bud break.  相似文献   
103.
The use of herbs as additives in livestock nutrition as an alternative to antibiotics is becoming a new goal in animal production. It is known that green tea exerts antimicrobial activity owing to specific flavonoid compounds named catechins, primarily represented by epigallocatechin-3-gallate (EGCG). Remarkably, despite many potential benefits of green tea and EGCG consumption, it is also important to get an insight on the possible reproductive-related consequences of feeding supplementation. To this purpose, granulosa cells were harvested from follicles > 5mm and treated with 5 and 50 microg/ml of EGCG in order to evaluate the effects on the main parameters of granulosa cell function: steroidogenesis, by measuring progesterone and estradiol-17beta production, and proliferation, one of the major feature of ovarian follicular growth. Moreover, as the genesis of new vessels has been demonstrated to be fundamental for follicle development, we evaluated the effect of EGCG on the production of the main angiogenetic factor, VEGF, by swine granulosa cells. Finally, since reactive oxygen species (ROS) might be involved in the control of female reproductive activity, we studied the effect of EGCG on superoxide anion (O2-) and hydrogen peroxide (H2O2) production by swine granulosa cells and on the activity of the scavenging enzyme superoxide dismutase (SOD). EGCG significantly (p < 0.05) inhibited proliferation, steroidogenesis, VEGF and O2- production by swine granulosa cells; on the contrary, H2O2 levels and SOD activity were stimulated (p < 0.05) by the catechin. Therefore, since our data demonstrate that EGCG has a negative effect on reproductive performances in swine, feeding supplementation should be carefully considered.  相似文献   
104.
A case of a feline Merkel cell tumour is described. An 8-year-old, female cat developed a round, alopecic, reddish mass on the nose. Wide excisional surgery was performed with cartilage resection. Histologically the mass was composed of solid islands of mostly basophilic densely packed cells with a scant cytoplasm, which was suggestive of a neuroendocrine origin. Results of immunohistochemical studies using antibodies against neurone-specific enolase, chromogranin, synaptophysin and pan-cytokeratin allowed classification of the lesion as a Merkel cell tumour. Ultrastructurally, dense core granules were identified in the cytoplasm. In a 2-year follow-up no relapses or metastases were observed. The clinical course recorded is in contrast with the malignant nature of a Merkel cell tumour recently described in a cat and of the human Merkel cell tumour, but is similar to the course of the canine Merkel cell tumour which is often benign. Early diagnosis along with the use of wide surgical excision might be considered an important factor in preventing relapse of this tumour.  相似文献   
105.
Herbicides entering the aquatic environment by spray drift, run-off and leaching to field drains may cause adverse effects on non-target aquatic vegetation. The potential for such effects has typically been evaluated from tests with floating, monocotyledonous Lemna sp. However, concern has been expressed as to whether this species could be used to indicate potential effects on other vegetation types, particularly rooted, submerged, emergent or dicotyledonous species. In 1997, the Centre for Aquatic Plant Management undertook development of new tests based on the additional species, Glyceria maxima (Hartm) Holmb, Lagarosiphon major (Ridl) Moss and Myriophyllum spicatum L. The resulting methodology was used to assess the effects of the sulfonylurea herbicide, sulfosulfuron on these species. Data presented here demonstrate that exposure to initial sulfosulfuron concentrations of 3.33 microg litre(-1) for up to 21 days was tolerated by these species and that adverse effects were observed only when plants were exposed to initial concentrations of 3.33 and 10 microg litre(-1) for 70 days. As the occurrence of such high initial concentrations for long periods is unlikely in the aquatic environment, sulfosulfuron is not expected to have adverse effects on the growth of these species. This study has also demonstrated that G maxima, L major and M spicatum grown in small outdoor tanks can be used successfully to assess the effects of crop-protection products on non-target aquatic flora.  相似文献   
106.
A polynucleate Rhizoctonia isolate (R3) was analysed for virulence, growth characteristics, enzyme production and presence of dsRNAs. Taxonomic position was assessed morphologically and by anastomosis group (AG) testing and ITS sequence analysis. Results indicated that R3 is a hypovirulent R. solani AG 4. Mechanisms underlying biocontrol towards virulent R. solani and Botrytis cinerea were investigated and plant-mediated resistance was followed using biochemical markers of defence (PR1, laminarinase, chitinase). Control apparently relies on spatial and nutrient competition in soil, and on systemic induced resistance. This is the first report on induction of systemic resistance and of defence markers by a hypovirulent strain of R. solani.  相似文献   
107.
BACKGROUND: Heparinized syringes are commonly used with point-of-care analyzers (eg, i-STAT) to measure ionized calcium (iCa(2+)); however there is little information about the validity of their use in canine patients. OBJECTIVE: To examine the suitability of prefilled (40 IU heparin/mL) and self-filled (150 IU heparin/mL) heparinized syringes for iCa(2+) measurements using the i-STAT analyzer. METHODS: Forty-seven blood samples were collected from 41 canine patients. Two milliliters of blood were collected into a 2-mL nonanticoagulated (NA) syringe, a commercially available preheparinized (PH) syringe (dry calcium-balanced lithium heparin, 40 IU/mL), and a 2-mL self-filled heparinized (SH) syringe (liquid sodium heparin, 150 IU/mL). iCa(2+) was measured in the sample using the i-STAT analyzer and a wet-reagent analyzer (KoneLab 30i) used as the reference instrument. Data were analyzed using paired t-tests, Pearson correlation coefficient, and Bland-Altman difference plots. RESULTS: There was no significant difference between the results obtained from NA and PH syringes using the i-STAT analyzer, and the correlation was excellent (r =.97). The i-STAT values from the SH syringes (mean, 1.07 mmol/L) were significantly lower (P<.001) than those from the NA syringes (mean, 1.38 mmol/L). iCa(2+) was significantly higher with the i-STAT analyzer than with the KoneLab analyzer for both the PH (mean i-STAT, 1.38 mmol/L vs mean KoneLab, 1.30 mmol/L) and SH (mean i-STAT, 1.07 mmol/L vs mean KoneLab, 1.03 mmol/L) samples. CONCLUSIONS: Blood samples collected in the PH syringes used in this study can be used interchangeably with those collected in NA syringes for measuring iCa(2+) using the i-STAT analyzer. SH syringes with high-concentration heparin products (5000 IU/mL) are unsuitable for measuring iCa(2+) because they cause clinically significant underestimations. Although there was good correlation between the i-STAT and KoneLab analyzers, the results should be interpreted using analyzer-specific reference intervals.  相似文献   
108.
109.
Numerous canine papillomaviruses (CPVs) have been identified (CPV1–23). CPV1, 2, and 6 have been associated with inverted papillomas (IPs). We retrieved 19 IPs from 3 histopathology archives, and evaluated and scored koilocytes, inclusion bodies, giant keratohyalin granules, cytoplasmic pallor, ballooning degeneration, and parakeratosis. IHC targeting major capsid proteins of PV was performed, and CPV genotyping was achieved by PCR testing. Tissue localization of CPV DNA and RNA was studied by chromogenic and RNAscope in situ hybridization (DNA-CISH, RNA-ISH, respectively). IPs were localized to the limbs (50%), trunk (30%), and head (20%), mainly as single nodules (16 of 19). In 15 of 19 cases, immunopositivity was detected within the nuclei in corneal and subcorneal epidermal layers. PCR revealed CPV1 in 11 IPs and CPV2 DNA in 3 IPs. Overall, 14 of 17 cases were positive by both DNA-CISH and RNA-ISH, in accord with PCR results. A histologic score >5 was always obtained in cases in which the viral etiology was demonstrated by IHC, DNA-CISH, and RNA-ISH. IHC and molecular approaches were useful to ascertain the viral etiology of IPs. Although IHC is the first choice for diagnostic purposes, ISH testing allows identification of PV type and the infection phase. RNA-ISH seems a promising tool to deepen our understanding of the pathogenesis of different PV types in animal species.  相似文献   
110.
The use of biomarkers as early-warning signals to assess the impact of pollutants and other environmental stressors in coastal habitats has been internationally recognized as a useful tool in marine coastal monitoring. We propose a similar approach to verify the welfare of edible shellfish, Ruditapes philippinarum, thus exploiting its possible application as an effective tool to verify the origin of fishing/aquaculture products. A selected battery of biomarkers was chosen and applied to organisms from two different habitats in the Lagoon of Venice (a farming site and a natural area where fishing is currently banned, because of pollution problems) and from a local market. Biological responses were evaluated physiologically (survival in air test and condition index), behaviourally (reburrowing rate), and histochemically (quantification of neutral lipids and lipofuscin). Micropollutants (heavy metals, PCBs, and PAHs) were also determined in the soft tissues. Results indicated clams from the farming site were in the best condition with regard to both chemical and biological measurements. In contrast, the market sample contained the highest concentrations of PAHs. PCBs and heavy metals varied slightly and quite irregularly among the three samples. The worst values of the biomarkers were observed for clams collected at the polluted site, where, in particular, the lowest physiological and behavioural indexes and the highest accumulation of lipofuscin in the digestive tissue were recorded.  相似文献   
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