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11.
Diego R. Macedo Robert M. Hughes Raphael Ligeiro Wander R. Ferreira Miriam A. Castro Nara T. Junqueira Deborah R. Oliveira Kele R. Firmiano Philip R. Kaufmann Paulo S. Pompeu Marcos Callisto 《Landscape Ecology》2014,29(6):1001-1016
Landscape and site-scale data analyses aid the interpretation of biological data and thereby help us develop more cost-effective natural resource management strategies. Our study focused on environmental influences on stream assemblages and we evaluated how three classes of environmental variables (geophysical landscape, land use and cover, and site habitat), influence fish and macroinvertebrate assemblage richness in the Brazilian Cerrado biome. We analyzed our data through use of multiple linear regression (MLR) models using the three classes of predictor variables alone and in combination. The four MLR models explained dissimilar amounts of benthic macroinvertebrate taxa richness (geophysical landscape R 2 ≈ 35 %, land use and cover R 2 ≈ 28 %, site habitat R 2 ≈ 36 %, and combined R 2 ≈ 51 %). For fish assemblages, geophysical landscape, land use and cover, site habitat, and combined models explained R 2 ≈ 28 %, R 2 ≈ 10 %, R 2 ≈ 31 %, and R 2 ≈ 47 % of the variability in fish species richness, respectively. We conclude that (1) environmental variables differed in the degree to which they explain assemblage richness, (2) the amounts of variance in assemblage richness explained by geophysical landscape and site habitat were similar, (3) the variables explained more variability in macroinvertebrate taxa richness than in fish species richness, and (4) all three classes of environmental variables studied were useful for explaining assemblage richness in Cerrado headwater streams. These results help us to understand the drivers of assemblage patterns at regional scales in tropical areas. 相似文献
12.
Gilberto Santos Andrade Dirceu Pratissoli Leandro Pin Dalvi Nicolas Desneux Hugo José Gonçalves dos Santos Junior 《Journal of pest science》2011,84(3):313-320
Trichogramma spp. are major parasitoids of lepidopteran pest eggs, but there is large variation in efficacy toward a given pest among
the numerous described Trichogramma species. It is important to select the Trichogramma species that most effectively parasitize and develop in target pest eggs for biological control. In this context, Trichogramma pretiosum, T. exiguum, T. atopovirilia and T. acacioi were studied in Heliothis virescens eggs under different thermal conditions. The parasitoids were reared at constant temperatures of 20, 25 and 30°C and tested
at these respective temperatures, while parasitoids reared at 25°C were also tested at 20 and 30°C, for a total of 20 species–temperature
combinations. About 30 H. virescens eggs were offered to the parasitoids for 24 h. Among the four species, parasitism rate by T. atopovirilia was highest at all temperature conditions, whereas T. acacioi had the lowest rates of parasitism at 25°C and 25/30°C. Parasitism ranged from 13.8 to 43.8% among all species–temperature
combinations. Viability (emerged parasitoids) ranged from 80.8 to 98.4%, and was deemed satisfactory. The emergence rates
of T. exiguum and T. acacioi were affected by temperature. Temperature also affected the sex ratio of T. exiguum at 25/30°C, whereas T. pretiosum and T. acacioi produced females predominantly independent of temperature. Overall, the parasitoid T. atopovirilia was the most efficient in parasitizing H. virescens eggs, though the levels of parasitism obtained might not ensure its successful use in biological control programs. The temperature-related
differences in biological traits observed in the four Trichogramma species tested hint at the importance of making careful choices regarding climatic conditions where the parasitoid is going
to be used when selecting a species for biological control programs. 相似文献
13.
The rhizobia-legume symbiosis is the main source of fixed nitrogen for many agricultural systems. However, it is inhibited by low soil temperature. To date, research on nodulation has involved either qualitative or destructive analyses. The use of computer-based image analysis potentially allows nodules to be followed during the course of development. Seedlings of bean (Phaseolus vulgaris L.), lentil (Lens culinaris Medik.) and pea (Pisum sativum L.) were transplanted into plastic growth pouches suspended in water baths maintained at 10, 15, 20 or 25 °C. Two days after transplanting, all plants were inoculated with appropriate rhizobial strains. Seven days after inoculation, plant roots were scanned; this was repeated weekly for 7 weeks. Data on nodule length were collected through image analysis. Nodule length was correlated with nodule size and development. There were increases in the precision of estimates of environmental effects through observation of individual nodule development, as opposed to averages for populations of nodules. The effects of root temperature on nodulation and nodule development were observed both in the delayed onset of nodulation and in reduced subsequent nodule growth rate, resulting in effects on final nodule size. 相似文献
14.
V. C. Baligar R. C. Sicher M. K. Elson Z. He J. O. De Souza Junior 《Journal of plant nutrition》2015,38(11):1787-1802
Productivity and sustainability of cacao (Theobroma cacao L.) in tropical soils are affected by levels of iron. Information is lacking on the cacao response to various sources of iron (Fe). A greenhouse experiment was conducted to evaluate the effects of five iron sources iron sulfate heptahydrate, ferric ethylenediamine-N,N’-bis(2-hydroxyphenylacetic acid), ferric diethylenetriaminepentaacetic acid, ferric ethylenediaminetetraacetic acid, fiesta herbicide (FeSO4 · 7H2O, FeEDDHA, FeDTPA, FeEDTA,) at 10 mg Fe kg?1 soil on growth, photosynthesis, content of photosynthetic pigments and starch and macro- and micronutrient nutrition of cacao. The various iron sources had significant effects on shoot and root dry biomass accumulation, leaf chlorophyll a and b content, carotenoid levels, SPAD index and PN. These parameters were significantly correlated with concentration, uptake, influx, and transport and use efficiency of Fe. In cacao net photosynthesis, stomatal conductance, internal carbon dioxide (CO2), and transpiration in leaf level responded differently to the sources of Fe. Invariably, macro and micronutrient uptake, influx, transport, and use efficiency showed differential responses to sources of iron but significant effects were only observed for copper (Cu), Fe, manganese (Mn), and zinc (Zn). Overall, FeDTPA, FeEDTA and FeHEDTA could be the best sources of Fe in improving, growth, photosynthesis and macro and micro nutrition of cacao. 相似文献
15.
Allen R. Stickley Jr. James F. Glahn Junior O. King D. Tommy King 《Journal of the World Aquaculture Society》1995,26(2):194-199
With the growth of channel caffish Ictalurus punetatus production in the Delta Region of Mississippi over the last 30 years have come concurrent depredation problems caused by great blue herons Ardea herodias . Biomass in stomachs from herons collected at catfish farms averaged 41% catfish, 38% sunfish Lepomis sp ., 17% shad Dorosoma cepedianum , and 4% gambusia Gambusia sp.; whereas observations of herons foraging indicated that 45% of the prey taken were gambusia. Our observational data indicate that herons take an average of 12 10-cm catfish fingerlings daily. The diurnal density of foraging herons on catfish ponds averaged 0.17 herons/ha in 1990, which means that the average 127-ha farm supports approximately 22 herons. Nocturnal foraging, especially on dark nights, appears to be minimal. If our data are approximately correct, the average catfish farm could be losing $30/ha per yr to herons, assuming that this catfish fingerling mortality can be attributed solely to heron depredation. 相似文献
16.
Júlia P. Gonçalves Aleksandra Oliveira-Menezes Arnaldo Maldonado Junior Técia M.U. Carvalho Wanderley de Souza 《Veterinary parasitology》2013
Echinostomiasis is a food-borne, intestinal, zoonotic, snail-mediated helminthiasis caused by digenean trematodes of the family Echinostomatidae with seven species of the genus Echinostoma infecting humans or domestic and wildlife animals. Echinostoma paraensei is a peristomic 37-collar-spined echinostome belonging to the “revolutum group”. 相似文献
17.
Wilson Wagner Ribeiro Teixeira Rafael Battisti Paulo Cesar Sentelhas Milton Ferreira de Moraes Adilson de Oliveira Junior 《Journal of Agronomy and Crop Science》2019,205(5):533-544
Soya bean yield gap can be caused by different factors resulting in uncertainties when the objective is to use such information for farm decision‐making and reference yield determination. Thus, this study aimed to quantify the soya bean yield gap for four sites, located in Southern and Midwestern Brazil, as well as the uncertainties of that related to cultivars, sowing dates, soil types and reference yields. The crop simulation model DSSAT‐CSM‐CROPGRO‐Soybean was calibrated for cultivars with similar maturity groups, based on the data obtained from the best farmers at the county level. The yield gap by water deficit (YGWD) was obtained through the difference between potential and attainable yields, and that one caused by sub‐optimum crop management (YGCM) by subtracting actual yield of each county, obtained from official statistics between 1989/90 and 2014/15 growing seasons, from the estimated attainable yield. The yield was simulated using four sowing dates, three soil types and two soya bean maturity groups by county. The reference yield uncertainty was quantified using yield reference from crop model and regional winners of the soya bean yield context, conducted by CESB (Brazilian Soybean Strategic Committee), for the growing seasons from 2013/14 to 2015/16. The crop model showed a good agreement between measured and simulated crop development and growth using calibration by maturity group, with low root mean square error (347 kg/ha). Southern sites had a mean YGWD of 1,047 kg/ha, while in the Midwest, it was lower than 100 kg/ha. The YGCM was 1,067, 528, 984 and 848 kg/ha, respectively, for Castro, PR, Mamborê, PR, Montividiu, GO and Primavera do Leste, MT, representing the opportunity for yield gain when having the best farmers as reference. The maturity groups, sowing dates and soil types showed to be an important source of uncertainty for yield gap determination, being recommended to investigate the farms in detail for an appropriate quantification. The reference yield showed expressive uncertainties, with some farmers presenting conditions to increase their soya bean yields by more than 3,000 kg/ha, when considering as reference the yields obtained by the winners’ farmers. These results show that uncertainties must be reduced when assessing farm yield gaps, in order to ensure that expected rate of soya bean yield growth could be reached by adopting the same technologies from CESB winners and best farmers in the county as a reference. 相似文献
18.
Tatiene R. M. Silva Flvia N. L. Barros Michele Bahia Francisco D. Sampaio Junior Sidney S. F. Santos Larissa S. Inoue Thamirys S. Gonalves Laerzio Chiesorin Neto Diogo C. L. O. Faria Camila Tochetto Gisele M. R. Viana Frederico O. B. Monteiro Gustavo Ges-Cavalcante Alessandra Scofield 《Zoonoses and public health》2019,66(7):798-804
The Brazilian Amazon is endemic for malaria and natural infections by Plasmodium spp. have been detected in Neotropical primates. Despite the diversity of primate species in the region, studies on infections by these agents are limited. The aim of the present study was to investigate the frequency of infection by Plasmodium vivax and P. falciparum in free‐born primates that were kept in captivity, in the western Amazon, Brazil. Blood samples were collected from 98 Neotropical primates. Detection of P. vivax and P. falciparum DNA was performed using a semi‐nested PCR, and the amplified products were sequenced. Plasmodium spp. DNA was detected in 6.12% (6/98) of the primates. P. vivax, and P. falciparum DNA was detected in 2.04% (2/98) and 4.08% (4/98) of these mammals, respectively. Sequencing and phylogenetic analysis confirmed the results obtained from the semi‐nested PCR. The presence of infected non‐human primates (NHP) can be auxiliary in the maintenance of P. falciparum and P. vivax and may have implications for the malaria surveillance and control in the Brazilian Amazon. It is necessary to structure an efficient surveillance system for the aetiological agents of malaria that infect NHP and humans to reduce the risk of Plasmodium spp. introduction into new areas, to protect all susceptible species. 相似文献
19.
Leandro G. Franco Carlos Henrique M. Wilges Daniel P. Junior Sofia A. Cerejo Lilian T. Nishimura Isabela P. Bittar 《Veterinary anaesthesia and analgesia》2018,45(3):250-259
Objective
To evaluate the effects of ketamine continuous rate infusions (CRI) at two dose rates on cardiovascular function and serum creatine kinase MB isoenzyme (CK-MB) and troponin I in healthy conscious dogs.Study design
Experimental, prospective, crossover, randomized, blinded study.Animals
Eight adult mixed-breed dogs, aged 6 ± 1 years and weighing 19 ± 8.6 kg (mean ± standard deviation).Methods
Dogs were administered an intravenous bolus of ketamine (0.5 mg kg?1) followed by a ketamine CRI for 12 hours (20 μg kg?1 minute?1; treatment TC20 or 40 μg kg?1 minute?1; treatment TC40). Sedation, heart rate (HR), mean arterial pressure (MAP), electrocardiographic and echocardiographic parameters were evaluated at baseline (T0) and 1 (T1), 2 (T2), 4 (T4), 8 (T8), 12 (T12) and 24 (T24) hours after ketamine infusion started. Serum concentrations of CK-MB and troponin I were measured at baseline and 12, 24 and 48 hours after infusion started.Results
HR increased over the first 4 hours, significantly at T1 in TC20 and at T4 in TC40 when compared with T0 (p < 0.05). MAP was significantly increased at T2 in TC40 when compared with TC20. Behavioral changes, such as stereotypical head movements and twitches, occurred within 4 hours in TC40. There were no significant changes in echocardiographic examinations in any dog when compared with baseline. There were no temporal changes in serum CK-MB activity either within or between treatments (p > 0.05). No troponin I was detected in any sample.Conclusions and clinical relevance
No indication of myocardial injury resulting from ketamine infusion was detected in this study in healthy dogs. Further studies are needed to assess the ketamine infusion effects on antinociception and other organ function not evaluated in the present study. 相似文献20.
Garcia JL Navarro IT Biazzono L Freire RL da Silva Guimarães Junior J Cryssafidis AL Bugni FM da Cunha IA Hamada FN Dias RC 《Veterinary parasitology》2007,145(3-4):197-206
This study evaluated a vaccine made from crude rhoptry proteins of Toxoplasma gondii with Quil-A, which was administered to cats by the intranasal route. Eleven short-hair domestic cats were divided into four groups: G1 (n=3) received three doses (200 microg/dose) of the rhoptry vaccine with Quil-A (20 microg); G2 (n=3) received PBS with Quil-A (20 microg); G3 (n=3) and G4 (n=2) received only PBS. Treatments were administered at days 0, 21, and 42 by the intranasal route. Challenge was done to G1, G2, and G3 animals with 600 cysts of the VEG strain on day 51 (challenge day); G4 animals were unchallenged. The anti-T. gondii IgG and IgA antibody levels from sera were measured by indirect enzyme-linked immunosorbent assay (ELISA). At challenge, two animals from G1 revealed antibody levels for both IgG and IgA; oocysts were not detected in feces of these two cats. There were no differences in hematological values between groups throughout the experiment (p>0.10). Preventable fractions were 67% in G1 and 0% in G2 and G3. Comparatively, G1 animals shed 89.3% and 90.8% less oocysts than G3 and G4, respectively. Two out of three cats were protected against T. gondii oocyst shedding when the rhoptry vaccine was administered by the intranasal route. This is the first study using crude rhoptry proteins as vaccine by the intranasal route in cats to evaluate protection against oocysts shedding. 相似文献