Miracle-dz/UniFAR-FTUs huggingface dataset:
Efficacy of pasture rejuvenation through mechanical aeration or N fertilization

Field experiments were conducted in 1991 and 1992 at five sites in central Alberta to determine if mechanical aeration with an Aer-WayTM aerator and/or N application would increase forage production on pasture or hayland. Mechanical aeration did not affect forage yield at any of the five sites. In contrast, forage yields increased significantly with N application in most cases. These results indicate that nutrient deficiency, particularly N, was the likely cause of reduced production on these pasturelands and haylands. Consideration of nutrient deficiency alleviation via inclusion of a legume or via N application may be an appropriate strategy for pastureland and hayland rejuvenation in central Alberta. Key words: Hayland, mechanical aeration, N fertilization, pasture, rejuvenation
Interactions between variety and the timing of conservation cuts on species balance in Lolium perenne-Trifolium repens swards

The effects of two periods of rest from grazing by sheep (either April-May or May-June) on the composition of swards of both an early-flowering (Aurora) and a late-flowering (Melle) perennial ryegrass variety grown with cither a small-leaved (Kent) or a medium-leaved (Milkanova) white clover variety are described. Compared with a continuously stocked treatment, the early rest period did not affect the mass of clover in the swards (expressed as a proportion of the total) but resulted in a subsequent decrease in its population density. The late rest period doubled clover mass in the swards at the time of cutting but did not affect the subsequent population density of clover. The magnitude of the change in mass during the late rest period depended on ryegrass variety, but not on clover variety. The adverse effect of the early rest period on the subsequent population density of clover was associated with the degree of shading experienced by clover laminae at the end of the rest period. Temperature may also have had an effect here as mean temperatures were cooler during the early rest period than during the late rest period. It is concluded that the effects of the two rest periods on the clover content of the swards were primarily due to timing, and less to inherent differences between ryegrass varieties.
Signalling in Rhizobacteria-Induced Systemic Resistance in Arabidopsis thaliana

To protect themselves from disease, plants have evolved sophisticated defence mechanisms in which the signal molecules salicylic acid, jasmonic acid and ethylene often play crucial roles. Elucidation of signalling pathways controlling disease resistance is a major objective in research on plant-pathogen interactions. The capacity of a plant to develop a broad spectrum, systemic acquired resistance (SAR) after primary infection with a necrotizing pathogen is well-known and its signal transduction pathway extensively studied. Plants of which the roots have been colonized by specific strains of non-pathogenic fluorescent Pseudomonas spp. develop a phenotypically similar form of protection that is called rhizobacteria-mediated induced systemic resistance (ISR). In contrast to pathogen-induced SAR, which is regulated by salicylic acid, rhizobacteria-mediated ISR is controlled by a signalling pathway in which jasmonic acid and ethylene play key roles. In the past eight years, the model plant species Arabidopsis thaliana was explored to study the molecular basis of rhizobacteria-mediated ISR. Here we review current knowledge of the signal transduction steps involved in the ISR pathway that leads from recognition of the rhizobacteria in the roots to systemic expression of broad-spectrum disease resistance in aboveground foliar tissues.
Dietary Carbohydrate Utilization by Fish

Aquaculture production is forecast to nearly double by the year 2010. Increased production can only be sustained with a concomitant increase in the production of aquafeeds. Presently, the protein source of choice in most aquafeeds is fish meal. Global fish meal production has remained relatively static over the past two decades, and there is no evidence to suggest that it will increase in the future. Therefore, alternative protein sources to fish meal will have to be found. Plant protein sources have been identified to have the greatest potential to replace fish meal protein. However, plant ingredients contain significant quantities of carbohydrates. The ability of fish to utilize dietary carbohydrates as energy sources to spare protein for growth varies, both among and within species. This review discusses the variability of carbohydrate utilization by fish commonly produced by aquaculture. Factors that affect carbohydrate utilization as an energy source to spare protein are carbohydrate origin, inclusion content, physical state, and molecular complexity. There appears to be potential for the use of supplemental enzymes to enhance carbohydrate utilization; however, care must be exercised with the use of such products as some of the breakdown products, particularly from nonstarch polysaccharides, such as galactose and xylose, are not tolerated by most fish if digested. The increased availability of these monomers may be detrimental to fish growth performance and health. Warmwater omnivorous fish have a greater potential to utilize dietary carbohydrate as an energy source to spare protein, than do coldwater and carnivorous species which utilize dietary carbohydrate poorly or not at all. This will place restrictions on the use of plant protein sources, which contain significant quantities of. carbohydrate in diets for coldwater and carnivorous fish. Consequently, the production costs of diets for warmwater omnivorous species will be cheaper than for coldwater and carnivorous species. This may have implications in the future for the selection of suitable species of fish to provide protein for human consumption.
Fatty acid changes during development of zygotic and microspore‐derived embryos of Brassica napus

Cultured microspores of Brassica napus L. cvs Topas and Reston initiated cell divisions within 3 to 4 days, and globular, heart and torpedo shaped embryos were prevalent after approximately 6, 8, and 10 days, respectively. Embryos with rudimentary cotyledons were evident within 2 weeks, but those that reached this stage of development represented only 1–5% of the original microspore population. The fresh weight of microspore-derived embryos at all stages of development was significantly greater than that for zygotic embryos, but the pattern of change in fresh weight and fatty acid accumulation was similar in developing zygotic and microspore embryos. In freshly isolated microspores of both Topas (low erucic acid) and Reston (high erucic acid), the predominant fatty acid was 18:3, while 18:1 comprised less than 15% of total fatty acids. During development in both zygotic and microspore embryos, the level of 18:3 declined markedly while 18:1 rapidly increased. Erucic acid (22:1) was not detected in the early stages of embryogenesis in Reston. However, small amounts of 22:1 appeared by early cotyledonary stage and the level gradually increased in both zygotic and microspore embryos through the later stages of development. The fatty acid compositions of mature embryos was nearly identical to that of dry seed, except the level of 22:1 in Reston embryos was consistently less than in the seed. Triacylglycerols comprised only 15% of total lipids in freshly isolated microspores, but increased to more than 90% by 4 weeks. The fatty acid composition of the triacylglycerol fraction was generally similar to that of total lipids at all stages of development of microspore-derived embryos.
Shading enhances the quality of willow leaves to leaf beetles – but does it matter?

Plant shading is commonly recognised as a factor, which increases susceptibility of plants to attack by herbivorous insects. In this study we experimentally investigated the effect of host plant shading on two willow-feeding leaf beetles, Galerucella lineola feeding upon Salix phylicifolia and Phratora vitellinae feeding upon Salix myrsinifolia. Both beetle species were more abundant on potted willows growing in open habitats than on the same clones placed under the shade of trees. However, in the laboratory the food preference by adults and larval performance showed that the shaded willows are actually better food for both beetle species. On the contrary, when larvae were reared in the field under natural abiotic conditions, we found no difference in larval performance, or if any, even better performance in open habitats. Apparently, higher and more variable daily temperatures in open habitats accelerated the growth of the larvae. When adults were let to emigrate from or immigrate to potted willows, which had been grown in the same conditions but placed either in the open or shady habitats, adults preferred exposed willows. Invertebrate predators were more abundant in open habitats, but we found no differences in leaf beetle mortality by natural enemies between the habitats. Although the larval performance appeared to be approximately equal in the two habitats during the unusually warm study period, we suggest that under suboptimal temperatures the better abiotic conditions of open sites can easily override the better food provided by shaded habitats. The selection of abiotic habitat thus plays a significant role in the adaptive habitat and host plant selection of these beetles within the gradient of shadiness.
Reactions of Plant Phenols with Myoglobin: Influence of Chemical Structure of the Phenolic Compounds

The reaction products of myoglobin and simple phenolic compounds, with different configurations of hydroxyl groups, and p-quinone were characterized in terms of selected properties (electrophoretic, chromato- graphic and mass spectrometric) and by in vitro digestion. The o-, and p-hydroxyphenols, p-quinone and gallic acid showed high reactivity leading to structural changes in myoglobin. In comparison, ferulic acid and m-hydroxyphenol reacted to only a small extent, especially affecting tryptophan fluorescence of myoglobin. The enzymatic digestion (tryptic, a-chymotryptic, peptic and pancreatic), on the basis of in vitro experiments with derivatized myoglobin,
Repetibilidade de características forrageiras do capim-elefante

The repeatability coefficient is widely used by geneticists as a measure of the upper limit of the heritability and as an efficient tool for predicting genotype value from successive measurements on individuals. It also allows to estimate whether the number of evaluations is sufficient to determine genotype superiority within a certain degree of reliability. The purpose of this research was to evaluate the coefficient of repeatability of crude protein concentration on stems and leaves, in 77 accesses of the Embrapa's Elephantgrass Germplasm Active Bank. The experimental design consisted of was randomized blocks, with two replicates. Forage was cut on 30, 45, 60 and 75 days of croping, using 15 sprouts of each experimental unit. ANOVA was performed for each trait data set, and genetic and environmental parameters were determined. The repeatability coefficients were estimated by the methods: Analysis of variance, principal components - correlation matrix, principal components - co-variance matrix and structural analysis - correlation matrix. Genetic variability was found among the genotypes for the appraised traits, which allowed the identification of genetically superior material that can be used in breeding programs. The coefficients of estimated repeatability were not different for the traits studied. Four cuts were enough for a coefficient of determination of 0.80, for all the methods. The use of seven cuts may enable predictions with 0.90 reliability for the studied traits, using any method.
Effects of Dietary Oxidized Cholesterol on Lipid Metabolism in Differently Aged Rats

Male Sprague-Dawley rats, 4 weeks (young) or 8 months (adult) of age, were fed one of three purified diets free of or containing either 0.5% cholesterol or 0.5% oxidized cholesterol (92% oxidized cholesterol) for 3 weeks. Feeding of oxidized cholesterol caused a significant reduction of food intake, body weight gain, and relative liver weight in rats of both ages. The activity of the HMG-CoA reductase and cholesterol 7α-hydroxylase of liver microsomes, the key enzymes in cholesterol synthesis and catabolism, respectively, was lowered by oxidized cholesterol compared to the diet free of cholesterol in both ages, and the difference was significantly in the adult. On the other hand, the activity of Δ6-desaturase of liver microsomes, a key enzyme in linoleic acid metabolism to arachidonic acid, was significantly increased by oxidized cholesterol in adult rats, leading to the increase in linoleic acid desaturation index [(20:3n-6 + 20:4n-6)/18:2n-6] in liver phospholipids. Oxidized cholesterol reduced the conc.
Response of Rainbow Trout to Different Food Web Structures in Northern Patagonia: Implications for Growth, Bioenergetics, and Invasiveness

Abstract Rainbow trout Oncorhynchus mykiss have successfully colonized almost all available water bodies in Patagonia. Introduction and restocking practices have taken place since the beginning of the 20th century without prior consideration of differences between environments in terms of fish community composition and trophic food web structure. We assessed how observed growth, growth efficiency, production, and biomass of rainbow trout populations from four Patagonian lakes were influenced by food web structure and prey quality, and we evaluated the growth strategies adopted by this species in response to environmental differences. Fish communities vary in terms of species composition and dominance. Bioenergetics simulations showed that size and growth patterns of rainbow trout varied between lakes, mainly owing to dietary differences. Fewer and lower-quality food items led to low growth efficiency and stunted growth, while a more diverse and higher-energy diet base led to higher growth efficiency and l.
Population dynamics of the freshwater dinoflagellate Ceratium hirundinella in the largest shallow lake of Central Europe, lake Balaton, Hungary

SUMMARY. 1 Horizontal distribution, long-term (1933–82) and short-term (day-to-day) changes in abundance, vertical stratification and circadian rhythm of the freshwater dinoflagellate Ceratium hirtmdinella were studied in Lake Balaton, the largest shallow lake of Central Europe. 2 The lowest abundance was consistently found in those areas of the lake which had the strongest currents. 3 The density of C. hirundinella seemed to be, at least in those parts of the lake above the level of fertility considered oligotrophic, insensitive to changes in trophic conditions; only its relative contribution to total biomass decreased with increased enrichment. 4 During the day the bulk of the population stayed at a level in which the light intensity was between 126 and 440 μE m-2 s-1 PAR.
Effect of soil acidity and liming on lucerne and following crops in central-western New South Wales

On some of the lighter textured soils in the wheatbelt of central-western New South Wales near Dubbo, soil acidity is a major problem, and lucerne (Medicago sativa) often establishes and grows poorly. We selected a site with a surface soil pHCa of 4.4 and an exchangeable aluminium of 0.4 cmol(+)/kg, which was also acidic down the soil profile. Experimental plots of 4 application rates of lime (nil, 1, 2 and 3 t/ha) in 4 replications were established. The site was limed in 1990 and lucerne sown in May 1991. Over the next 6 years the trial was periodically grazed with sheep, and lucerne regrowth and stand density were monitored. In October 1997, the lucerne was removed and 3 crops of varying acid tolerance (wheat, barley and canola) were sown as split plots in both 1998 and 1999. Lucerne density was higher in the limed plots compared with the unlimed treatment, and this difference persisted for 6 years. Dry matter production of lucerne was increased by lime applied at rates up to 2 t/ha. All 3 crops sown after the lucerne phase responded to lime applied 8 and/or 9 years earlier. The responses were attributed to the strong residual effect of the lime in the 0–10 cm soil layer, to smaller improvements in the 10–20 cm zone (possibly due to the movement of lime down the soil profile over the 7 years before the date of measurement) and to carry over effects of nitrogen fixation by the lucerne into the cropping phase. The protein content of the wheat grain was increased concurrently with grain yield due to the previous liming and resultant legume nitrogen effects. The results support the application of lime to improve the productivity of lucerne and subsequent crops, even when the soil is acidic to depths below the cultivation layer.
Availability Of Fish Fauna In Some Selected Districts In Bangladesh

A check-list of 139 species of fishes of both exotic and indigenous origin belonging to 34 families and 87 genera available in the rivers, beels, haors, ponds and swamps of the greater Mymensingh (Mymensingh, Kishoregonj, Netrakona, Jamalpur and Sherpur) districts of Bangladesh is presented. The number of species, genera and family of fishes reported in Mymensingh regions is still rich in fresh water fish fauna. The systematic, ecology, Distribution, habits of these fish fauna of greater Mymensingh region need to be studied. DOI: http://dx.doi. org/10.3329/bjas.v38i1-2.9924 BJAS 2009; 38(1-2): 151-163
Growth and Nutritional Responses of Juvenile Jeffrey Pine to Post-Planting Fertilization

Abstract Broadcast fertilization of a three-year-old Jeffrey pine (Pinus jeffreyi Grev. & Balf.) plantation growing on an eroded Sierra Nevada site was examined for its capacity to enhance seedling growth. The amendments chosen for the study included controlled release and conventional soluble formulations that contained a variety of N forms, but all featured high N content along with other nutrients. Four application rates were used, and all amendments were distributed around the base of the seedlings as top dressing. Four seasons after treatment application, fertilized seedlings were 129% larger in height, 93% larger in diameter, and 865% greater in shoot volume than unfertilized seedlings overall. Seedling sizes generally increased with application rate, and by a small margin, the controlled release fertilizer outperformed the other formulations. Relative growth analysis suggested that stimulation by the amendments would continue beyond four seasons. Foliar analysis conducted early and again late during the study revealed that N and P concentrations were consistently raised by fertilization, which likely accounts for much of the accompanying growth gains, while Ca, Fe, Mn, B, and Al concentrations were consistently reduced. Either early or late, foliar K was also raised while Mg, S, Zn, and Cu were reduced. Collectively, these results indicate that fertilization with a variety of high N formulations can increase the availability and uptake of critical nutrients sufficiently to impart in Jeffrey pine on low quality sites a substantial growth advantage.
EFFECT OF MARIJUANA ON THE GLUCOSE‐TOLERANCE TEST *

The sensation of hunger or increased appetite is not uncommonly reported during marijuana smoking or hashish ingestion. The symptom of “marijuana hunger” has been known for many years, and frequently a special craving for sweets has been described. Hunger comes on at various intervals following the drug, up to three hours afterward or longer. ’ Ames2 reported that although his subjects did not experience hunger during the first three hours after Cannabis, they ate with great relish when food was offered. Recently HollisteI3 published studies that further document reports of increased appetite and hunger after oral administration of marijuana. Furthermore, there was actually increased total food intake (chocolate milk shakes) when this was measured. Hollister noted that stimulation of appetite by marijuana was by no means invariable, since it occurred in only slightly more than half the subjects. While rodents given marijuana extract generally show a decrease in fighting a striking increase in aggressive behavior occurs after the drug if food is simultaneously withheld.6 The change is more marked in female rats. Hypoglycemia, or rapid decreases in blood-glucose levels, are known to be associated with sensations of hunger or increased appetite. These symptoms are present whether the blood-sugar lowering occurs spontaneously or is due to antidiabetic drug therapy. Several observers have considered the possibility that the hunger sensation occurring after marijuana may develop because the drug lowers blood-sugar levels. Miras,’ Hollister’ss and Weil’s9 groups have all reported, however, that neither smoked marijuana in small doses nor orally ingested tetrahydrocannabinol (THC) in large doses has any significant effect on peripheral glucose levels. In some of these studies the subjects were not fasting, and in none of them were the effects of marijuana on carbohydrate metabolism evaluated in a systematic fashion. The present study was designed to clarify further the possible role of hypoglycemia or alterations in blood-glucose levels in the genesis of “marijuana hunger. ” Some slang synonyms for marijuana, as currently used in the United States, are as follows: grass weed pot joint stick reefer loco weed hashish Texas tea roach Acapulco gold smoke.
Population changes within a group of fish species in Lake Tanganyika following their exploitation

Pelagic fish populations in Lake Tanganyika consist mainly of two small clupeid species and four centroponiid species which prey on them. Exploitation with purse-seines began in the southeast arm in 1962 and catches were sampled up to early 1969. Inshore clupeid populations were also sampled with a scoop-net (lusenga of the kind used in the traditional inshore fishery. Clupeid biomass reached annual maxima around September. One clupeid species, Stolothrissa tanganicae Regan, dominated pelagic catches except in 2 years when about equal quantities of the other clupeid, Limnothrissa miodon Blgr. were caught. Numbers of each predator (three species of Lates and Luciolates stappersii Blgr.) decreased from 1963 to 1966 and remained low thereafter. The clupeid catch rose from 1964 to 1967 and remained high in 1968. The average nightly catch weight per year of all species together altered relatively little. Changes in population size distributions occurred. Sampling methods were concluded to be valid for clupeid populations, but probably indi-cated only general changes in predator populations. Clupeid life-cycles are mostly accomplished within a year, and appear closely related to the periodic and spatial variations in plankton production. The two species are competitive and can replace one another in the pelagic zone. Certain distribution patterns of the clupeids and of the predator young are believed to be adaptations to severe predation. Low replacement rates under fishing pressure account for the decline of predator species, and the clupeid increase resulted from reduction in predation. A fairly stable exploited phase has apparently been reached in which clupeid biomass is much greater and predator biomass much less than in the natural state. The data encourage certain predictions. Similar major trends occurred in the much larger fishery in the Burundi sector of the lake.