Rabies virus infection in Aedes pseudoscutellaris cells: a study on receptorial structures     

L Seganti  F Superti  L Sinibaldi  M Marchetti  S Bianchi  N Orsi 《Comparative immunology, microbiology and infectious diseases》1991,14(3):265-275

Rabies virus is able to infect in vitro a wide range of homeothermic and poikilothermic cells but little is known about its multiplication in arthropod cells. In this research the infection of rabies virus in Aedes pseudoscutellaris cells, a mosquito cell line susceptible to mosquito-borne viruses, was studied. After 60 days of incubation at 26 degrees C up to 70% of infected cells showed the synthesis of both viral nucleocapsid and envelope antigens, although viral yield and cell damage could not be detected. Research performed in order to investigate the role of membrane carbohydrate moieties in rabies virus-mosquito cell interaction suggested the participation of galactose and N-acetylglucosamine whereas sialic acid, known to be a rabies binding site in many homeothermic cell lines, was not involved.  相似文献   

Growth response of Ficus benjamina to limited soil volume and soil dilution in a skeletal soil container study     

Felix C.W. Loh  Jason C. Grabosky  Nina L. Bassuk 《Urban Forestry & Urban Greening》2003,2(1):53-62

The interactive effects of rooting volume and nutrient availability in a skeletal soil medium designed to meet street tree and pavement needs were observed in a containerized experiment. Benjamin fig (Ficus benjamina L.) was grown in a stone-soil blended skeletal soil material (CU-Soil™) and compared to a loam soil. The same topsoil used as the soil component in the skeletal soil material was used as the sole component in the comparison soil-only treatment.Plants grown in the skeletal soil material had reduced leaf tissue N content and depressed growth compared with plants grown in non-diluted soil. No other mineral deficiencies were found. Leaf number, chlorophyll concentration, shoot weight, and root characteristics were all affected.Reduced growth from soil dilution could be offset by the provision of an enlarged rooting volume for root development. Large containers of skeletal soil were observed to have smaller root systems compared to equivalent net volumes of loam soil at the first two harvest dates of the study. By the end of the study, the large containers of skeletal soil were observed to have developed larger root systems compared to equivalent net volumes of loam soil; resulting in comparable leaf N levels and total plant dry matter. Plants in skeletal soil had lower shoot: root ratios at the end of the study. Investing resources to further root growth in times of nutrient shortages is a probable plant reaction as evidenced by differences in specific root length between treatments. The study allowed a method for directly partitioning the containerization effect by having equivalent amounts of soil over two volumes.  相似文献   

Regional variability in landscape effects on forest bird communities     

Spake  Rebecca  Soga  Masashi  Kawamura  Kazuhiro  Cooke  Robert S.  Yamaura  Yuichi  Eigenbrod  Felix 《Landscape Ecology》2020,35(5):1055-1071

Landscape Ecology - Functional responses to landscape heterogeneity are context-dependent, hampering the transferability of landscape-scale conservation initiatives. Japan provides a unique...  相似文献   

Variation in parasitoid attraction to herbivore-infested plants and alternative host plant cover mediate tritrophic interactions at the landscape scale     

Aartsma  Yavanna  Hao  Yueyi  Dicke  Marcel  van der Werf  Wopke  Poelman  Erik H.  Bianchi  Felix J. J. A. 《Landscape Ecology》2020,35(4):907-919

Landscape Ecology - Tritrophic interactions may be affected by local factors and the broader landscape context. At small spatial scales, carnivorous enemies of herbivorous insects use...  相似文献   

Intake,performance, and carcass characteristics of lambs fed spineless cactus replacing wheat bran     

Sabrina Carla Rodrigues Felix  Ricardo Alexandre Silva Pessoa  Marcelo de Andrade Ferreira  Luciana Felizardo Pereira Soares  Janaina de Lima Silva  Karen Santos Felix de Abreu  Ana Caroline Cerqueira de Melo 《Tropical animal health and production》2016,48(2):465-468

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Quantification of stress sensitive markers in single fecal samples do not accurately predict excretion of these in the pig   总被引：1，自引：0，他引：1  

Carlsson HE  Lyberg K  Royo F  Hau J 《Research in veterinary science》2007,82(3):423-428

All feces produced during 24 h were collected from five pigs and cortisol and immunoreactive cortisol metabolites (CICM), and IgA were quantified. Within pigs, the concentrations of CICM and IgA varied extensively between random samples obtained from a single fecal dropping, and deviated in most cases significantly from the true concentration measured in total fecal output (CV 6.7-130%). The CICM and IgA contents varied considerably (CV 8.1-114%) within and between individual fecal droppings from the same pig compared to the total fecal excretion. In conclusion, single random samples could not be used to reliably quantify the total fecal concentration or excretion of CICM or IgA in pigs. Analyses of all feces collected during shorter periods than 24 h did not provide an accurate estimate of the daily excretion of CICM. Thus, the concentration of stress sensitive molecules in random single fecal samples as an indicator of animal welfare should be interpreted with prudence.  相似文献   

Modelling the interaction between a pest (Aculops lycopersici), two predators (Pronematus ubiquitus and Macrolophus pygmaeus) and climate variables: a 3-year greenhouse study in a tomato crop     

Rob Moerkens  Dominiek Vangansbeke  Marcus V. A. Duarte  Stijn Bellinkx  Elana De Roo  Juliette Pijnakker  Felix Wäckers 《Pest management science》2023,79(12):5362-5373

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Current knowledge about the processes of luteolysis and maternal recognition of pregnancy in camelids     

Carolina Paula Bianchi  Maria F. Gallelli  Juan Manuel Herrera  Micaela A. Benavente  Liliana Rossetto  Marcelo Alfredo Aba 《Reproduction in domestic animals》2023,58(1):3-9

Camelids have many unique reproductive features that considerably differ from those of other domestic species. Females are induced ovulators with subsequent development of a corpus luteum (CL) with a short lifespan. Plasma progesterone concentration starts to increase on day 4, peaks on day 8–9 and, in non-pregnant animals, basal concentration is reached around day 10–11 post-induction of ovulation. Luteolytic pulses of prostaglandin F_2α (PGF_2α) are firstly detected on day 7 or 8 (approximately on day 5–6 after ovulation), with maximal luteolytic peaks observed between days 9 and 11 post-mating, in coincidence with a high endometrial expression of cyclooxygenase 2, a limiting enzyme in prostaglandins synthesis. Unlike other species, oxytocin seems not to be involved in the luteolytic process in these species. The CL is the main source of progesterone secretion, and its function is required to support pregnancy. Despite constant research efforts, aspects of reproduction and maternal recognition of pregnancy in camelids remain not fully understood. A transient decrease and subsequent recovery in plasma progesterone concentration are observed after day 9 post-mating in pregnant animals in association with a pulsatile release of PGF_2α and a transitory decrease in CL vascularization. Thus, embryo recognition should occur between days 8 and 12 post-mating. In camels, conceptus tissues exhibit aromatizing activity with the capacity to synthesize large amounts of oestradiol. Similarly, llama blastocysts secrete oestradiol-17β during the preimplantation stage, with a higher production during the elongation period. An increase in the endometrial expression of oestrogen receptor α is also observed on day 12 post-mating. All these evidences suggest that oestrogen could be the signal released by the embryo at the time of its recognition in camelids. Besides, nearly 98% of pregnancies are carried out in the left horn. A decrease in the endometrial expression of mucin 1 and 16 genes has been reported, suggesting that these changes are crucial for successful embryo implantation; however, no differences have been observed between horns. Thus, maternal recognition of pregnancy in camelids is a particularly complex process that must occur in a concise time to allow the rescue of the CL and embryo survival.  相似文献   

Identity of mass-flowering crops moderates functional trait composition of pollinator communities     

Beyer  Nicole  Kirsch  Felix  Gabriel  Doreen  Westphal  Catrin 《Landscape Ecology》2021,36(9):2657-2671

Landscape Ecology - Pollinator declines and functional homogenization of farmland insect communities have been reported. Mass-flowering crops (MFC) can support pollinators by providing floral...  相似文献   

Effects of Azoxystrobin on Mycotoxin Production in a Carbendazim-Resistant Strain ofFusarium sporotrichioides     

J. P. Felix D’Mello  Ann M. C. Macdonald  Rosalie Rinna 《Phytoparasitica》2001,29(5):431-440

Carbendazim-resistant (RS) and control (CS) strains ofFusarium sporotrichioides Sherb., previously developed in our laboratory, were exposed to graded concentrations of azoxystrob in in broth media under shake-culture conditions for 2, 3, 4 and 8 days. Azoxystrobin concentrations were 0, 1, 10 and 100 mg 1^-1 broth and cultures were incubated at a constant 25°C. Mycelial growth was significantly affected by strain (P<0.01), azoxystrobin concentration (P<0.001) and incubation time (P<0.001). Combined results for the four incubation times showed that CS yielded higher mycelial mass than RS (P<0.01) only in the absence of azoxystrobin. At fungicide additions of 1, 10 and 100 mg P^-1 mycelial growth was reduced (P<0.001) with minimal strain differences (P>0.05) at all three doses of azoxystrobin. Significant (P<0.05 or better) strain-fungicide interactions were recorded in trichothecene production following exposure to azoxystrobin. At 4 and 8 days of incubation, the 10 mg 1^-1 addition of azoxystrobin stimulated T-2 toxin synthesis (P<0.05) only in RS cultures. In contrast, T-2 toxin enhancement in CS cultures occurred only on day 8 but at a lower level of azoxystrobin (1 mg1^-1). Thus, the stimulation of T-2 toxin synthesis depended upon strain and azoxystrobin level. Production of diocetoxyscirpenol (DAS) was affected by a more complex set of interactions. Overall means showed that, in comparison with initial values (on day 2 or 3), DAS output maximized significantly(P<0.05) on day 4 in RS cultures and on day 8 in CS. Marked strain effects were observed on exposure to the 10 mg 1^-1 level of azoxystrobin. At this level, DAS production was enhanced in RS only after 4 (P<0.01 ) and 8 (P<0.05) days of incubation, while in contrast, CS reduced DAS production. As with T-2 toxin, DAS production in CS was stimulated (P<0.05 or better) only at low exposure levels of azoxystrobin. In the case of neosolaniol (NEO), however, the main effect of strain was significant (P<0.05), with CS producing consistently more of the mycotoxin than RS on day 4 of the experiment. At this point, the NEO:T-2 toxin ratio was also higher in CS (0.63) than in RS (0.12), a feature reported by us previously. In conclusion, the present investigation has shown for the first time that the development of resistance to one fungicide can affect trichothecene production inF. sporotrichioides on exposure to a second fungicide. These results have been incorporated into a new classification scheme for fungicide efficacy which is also presented in this paper. http://www.phytoparasitica.org posting Oct. 7,2001.  相似文献