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1.
Lidiane Cristina Gonçalves de Sandre Hellen Buzollo Thiago Matias Torres do Nascimento Lígia Maria Neira Eduardo Gianini Abimorad Rosangela Kiyoko Jomori Carlos Ducatti Maria Célia Portella Dalton José Carneiro 《Journal of the World Aquaculture Society》2016,47(1):113-122
This study evaluated the application of stable isotopes of carbon as an alternative and more accurate method to determine gastrointestinal transit time (GTT) in fish by comparing it to the inert marker method. The stable isotope method detects alterations of the normal carbon flow in a biological system by analyzing naturally occurring isotopes of carbon, contrary to studies based on conventional techniques that apply external markers to the diet to determine GTT through visual observation of the color change in feces. Therefore, 320 pacu, Piaractus mesopotamicus juveniles were reared in 32 tanks under two different temperatures (25 and 29 C). The pacu juveniles received two different diets, one based on ingredients derived from C3 photosynthetic cycle plants and the other based on C4 plant ingredients, both containing titanium oxide (TiO2) as a marker. After 40 d, the isotopic signature of the diets was changed, and the marker was replaced by chromic oxide (Cr2O3). In the isotopic technique, the feces were analyzed to determine the exchange in the isotopic ratio of carbon δ13C. Both methods found that GTT was faster (nearly 6 h) in fish at 29 C when using the C4/C3 feeding strategy and slower in fish at 25 C using the C3/C4 strategy (15 h by inert marker and 18 h by the isotopic method). In conclusion, GTT determination in pacu juveniles using the stable isotope technique exhibits the same accuracy obtained with the inert marker method at temperatures suitable (nearly 29 C) for the metabolism of these animals. 相似文献
2.
Annet Namayanja Robin Buruchara George Mahuku Patrick Rubaihayo Paul Kimani Stephen Mayanja Hellen Eyedu 《Euphytica》2006,151(3):361-369
Inheritance of resistance to angular leaf spot (ALS) disease caused by Phaeoisariopsis griseola (Sacc.) Ferr was investigated in two common bean cultivars, Mexico 54 and BAT 332. Both Andean and Mesoamerican backgrounds were used to determine the stability of the resistance gene in each of the two cultivars. Resistance to P. griseola was phenotypically evaluated by artificial inoculation with one of the most widely distributed pathotypes, 63–39. Evaluation of the parental genotypes, F1, F2 and backcross populations revealed that the resistance to angular leaf spot in the cultivars Mexico 54 and BAT 332 to pathotype 63–39 is controlled by a single dominant gene, when both the Andean and Mesoamerican backgrounds were used. Allelism test showed that ALS resistance in Mexico 54 and BAT 332 to pathotype 63–39 was conditioned by the same resistance locus. Resistant and susceptible segregating populations generated using Mexico 54 resistant parent were selected for DNA extraction and amplification to check for the presence /absence of the SCAR OPN02 and RAPD OPE04 markers linked to the Phg-2 resistance gene. The results indicated that the SCAR OPN02 was not polymorphic in the study populations and therefore of limited application in selecting resistant genotypes in such populations. On the other hand, the RAPD OPE04 marker was observed in all resistant individuals and was absent in those scored susceptible based on virulence data. Use of the RAPD OPE04 marker in marker-assisted selection is underway. 相似文献
3.
The present study describes the antispasmodic activity of some fractions from the bark of Persea cordata, against guinea pig ileum contracted by acetylcholine and histamine. Hexane and dichloromethane fractions demonstrated the most promising biological effects, having similar potency to that of papaverine, a well-known antispasmodic agent. 相似文献
4.
Schuindt SH Oliveira BC Pimentel PM Resende TL Retamal CA DaMatta RA Seipel D Arnholdt AC 《Veterinary parasitology》2012,186(3-4):207-215
Toxoplasmosis is a world wide spread zoonosis caused by Toxoplasma gondii, an obligate intracellular parasite that is able to disseminate into deep tissues and cross biological barriers, reaching immunoprivileged sites such as the brain and retina. The parasite is able to infect macrophages and dendritic cells for dispersal throughout the body. However, the molecular mechanisms or outcomes of the subversion of the host cell are largely unknown. Recently our group established that metalloproteinases are involved in migration of infected macrophages. Herein, we evaluated the recruitment of host invasive machinery components in T. gondii infected murine macrophages. We showed by immunoprecipitation assays that MMP-9, CD44 TIMP-1 and uPAR were secreted as a multi-protein complex by infected macrophages. Zymographic analysis revealed that MMP-9 was present in its pro- and active form. Moreover, inhibition of uPA/uPAR pathway by PAI-1 decreased secretion of MMP-9 active forms, as well those associated to uPAR and TIMP-1, but not to CD44. Data presented here suggest that MMP-9 is secreted as a multiprotein complex by T. gondii infected macrophages, similar to that observed in metastatic cells. We further speculate that uPA/uPAR system is involved in the expression/secretion of complexes containing active MMP-9 forms. 相似文献
5.
Maria Moraiti-Ioannidou Jeanne Castritsi-Catharios Hellen Miliou & Yannis P Kotzamanis 《Aquaculture Research》2007,38(15):1664-1672
Evaluation of a new‐to‐science Artemia population and comparison with four other existing populations were carried out. Five parthenogenetic Artemia populations from the following Greek saltworks were studied: Alyki (a new population), Kalloni, Milos, Polychnitos and Messolongi. The diameters of non‐decapsulated and decapsulated cysts as well as the lengths of nauplii instar stages I, II and III were measured. In addition, the fatty acid composition of decapsulated cysts was estimated. The cyst size of the Alyki population was the smallest, with the largest chorion found in Greece so far. The Messolongi population had the largest cysts, with the smallest chorion of all five populations. The diameter of the non‐decapsulated cysts was highly related (P<0.01) to the length of the nauplii instar I, II and III. The diameter of decapsulated cysts was found to be the most stable and reliable biometric characteristic. The study of their fatty acids profiles revealed that the Polychnitos and Messolongi populations are suitable as live food for freshwater species, while the Alyki, Milos and Kalloni populations are suitable for marine species, having high levels (8.9%, 11.2% and 12.5% respectively) of eicosapentaenoic acid and detectable amounts (0.3%, 0.1% and 0.2% respectively) of docosahexaenoic acid. 相似文献
6.
Hellen Buzollo Lidiane Cristina Gonalves de Sandre Ligia Maria Neira Thiago Matias Torres do Nascimento Rosngela Kiyoko Jomori Dalton Jos Carneiro 《Aquaculture Nutrition》2019,25(3):669-679
Several investigations have been carried out to improve the productivity of tambaqui, an economically important fish species in Brazil and other Latin American countries. This study determined the digestible protein (DP) requirements in juvenile tambaqui by assessing their productive performance and nutritional efficiency. It also evaluated the effects of different dietary DP levels on the morphology and cellularity of skeletal fast muscle fibres. The 1750 tambaqui tested (6.53 ± 0.43 g body weight, 7.58 ± 0.18 cm length) were randomly distributed into 35 tanks. Fish were fed one of the seven isocaloric diets, which contained 140, 170, 200, 230, 260, 290 or 320 g/kg DP. The DP requirement, calculated by segmented (broken line) regression of weight gain data, was 290 g/kg. An increase in diet DP to 290 g/kg significantly improved final weight, weight gain, feed intake, specific growth rate and crude protein gain, and changed fibre diameter in deep muscle. Muscle fibres were randomly distributed into a mosaic pattern, characterized by fibres with different diameters. Treatments with 290 and 320 g/kg DP increased the frequency of large‐diameter fibres (>50 µm), indicating hypertrophic growth of skeletal muscle during the juvenile phase, which occurred in conjunction with hyperplasia. 相似文献
7.
Hellen Ninsiima Kayaga Frank Kagoda Mildred Ochwo-Ssemakula Boris Mahulé Elysé Alladassi Godfrey Asea Paul Gibson Richard Edema 《Journal of Crop Science and Biotechnology》2017,20(4):255-262
Although many studies have been conducted on gene action of grain yield and yield related traits in maize, none of them focused on highland maize in Uganda. This study was conducted to establish the gene action controlling inheritance of yield and its related traits in highland maize hybrids. Thirty-six F1 hybrids generated from a 9 x 9 half diallel mating design, were planted with two local checks in three highland locations; Kalengyere, Kachwekano, and Buginyanya with two replications using a 2 x 19 alpha (0, 1) lattice design. Results showed that inheritance of ear length and anthesis-silking interval was controlled by both additive and non-additive gene action while the inheritance of days to anthesis, days to silking was mainly controlled by additive gene action. The inheritance of grain yield and other yield related traits was greatly influenced by environment and genotype x environment interaction. Considering the great influence of the environment and genotype x environment interaction on most of the traits including grain yield, further testing in additional locations over more seasons and broadening the genetic base of the parents is encouraged. 相似文献
8.
Summary The indigenous Maori people quickly adopted early introductions of potatoes into New Zealand. These early cultivars known
as Maori Potatoes are smaller in size and differently coloured when compared to modern potato cultivars and are thought to
have remained unselected. The glycoalkaloid content of tubers ranged from 38.7 to 142.6 mg kg−1 (mean 76.5). A taste test conducted on 10 different cultivars showed that they were generally well accepted; however all
panellists noted a slightly bitter after taste in some of the cultivars. The texture and flavour were within acceptable limits
for all the cultivars tested. 相似文献
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10.
Onyango Irene Awino Robert Skilton Shadrack Muya Samuel Kabochi Hellen Kutima Muo Kasina 《East African Agricultural and Forestry Journal》2017,82(1):23-35
Varroa mite (Varroa destructor Anderson and Trueman) is a major global threat to the western honey bee (Apis mellifera L.). The ectoparasite has been implicated in the spread of honeybee viruses. Beekeeping plays a major role in transmission of the mite. The study aimed at assessing levels of Varroa infestation, bee viruses and bacteria incidences in domesticated honeybee colonies. Samples of adult honey bees, bee brood and Varroa mites were collected from Baringo, Narok, Kwale, Magarini, Voi, Ijara, Busia and Siaya in Kenya. Ten hives in each site were inspected for the presence of Varroa mites on adult bees using the icing sugar technique and forceps in sealed brood cells. The number of mites observed were recorded per site. Ribonucleic acid was extracted from the mites, brood and adult bees and a polymerase chain reaction was performed to detect the black queen cell virus. Pooled RNA samples of brood and adult bees were used in next generation sequencing on a 454 GS FLX platform to detect bee viruses and bacteria. Varroa mites were reported in all the study sites at varying levels. The black queen cell virus and three iflaviruses, European foul brood and its secondary causative agent Enterococcus faecalis were reported. The Kenyan honeybee population is threatened by bee pests and pathogens. There is a need for constant monitoring of bee pests and diseases in honeybee colonies in the country for early detection and to provide data on the status of bee health. All stakeholders in the beekeeping value chain should be enlightened on their role in pest and disease transmission. 相似文献