977 resultados para time of application and nutrient leaf content


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This paper marks the first in a series of studies into the potential use of pyrolysis products in the development of more sustainable practices within the agricultural industry. In this study, the immediate benefits of the application of biochar to crop yields of Raphanus sativus (radishes) are assessed. Furthermore, the study reports on the preliminary findings into the potential application of pyroligneous acid (wood vinegar) as a biocidal agent against crop disease. Although germination tests undertaken on biochar/compost blends of up to 1: 2, by weight, showed no significant adverse effect from the addition of the nutrient rich carbonaceous solid, evidence of substantial increases in crop yield through the addition of biochar were not observed. In sharp contrast, zones of inhibition were observed at 3-10 vol. % upon application of pyroligneous acid to two causal agents responsible for certain diseases in vegetable and fruit crops, i.e. Rhizobium radiobacter (agrobacterium tumefaciens) and Xanthomonas campestris, highlighting the versatility in the application of pyrolysis products and avenues for exploration in the development of this biomass conversion technology.

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Due to the communist regime in Hungary the values and principles of the Second Vatican Counsil could hardly achieve their goal in the region and the situation is almost the same even today. This paper examines two levels of society where the thoughts of Gaudium et spes might have appeared: we have explored that there are Christian companies existing about 15 years since the political transition in 1990 and we made a research among individuals in rural environment, how could they preserve their human wholeness described in GS, in other words, how could they keep their social, cultural, natural, religiuos and local roots amongst the consumer society that has been developped in Hungary at the time of capitalism. Regarding the Christian companies our research could produce a positive result: we have explored that although the Christian companies survayed hardly know the Church’s social doctrine, they live and operate according to it. At the same time in the realm of individuals we cannot tell good news of this kind. Most of the persons interviewed have already lost or are near to loose their roots, that is their human wholeness. Our final conclusion is that our hope for preserving even strenghtening the values of GS in the Hungarian society is in the communities, be it work communities, as John Paul II. mentioned in his encyclical Sollicitudo rei Socialis. The paper presents the details and conclusions of our researches.

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At the time of the economic crisis cutting marketing and media expenses is a common corporate reaction. While this reaction is rather obvious, this may not be the winning option. To find out more about successful media strategies authors conducted a broad, multiple method research, including interviews with industry experts (N=6, leading decision makers), scrutiny of consumer narratives (N=100), content analysis of forum and blog entries (N=7086 comments) and focus group interviews (N=4). Research findings point to realignment in media spending namely better-targeted communications programs and more fragmented media choice, and besides, show the increasing role of audience participation, too. Authors argue that careful managerial efforts for harmonizing consumer problems and advertising content may result in finding the path from problem level to desired level in marketing communication practices even in crisis periods.

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The distribution of mangrove biomass and forest structure along Shark River estuary in the Florida Coastal Everglades (FCE) has been correlated with elevated total phosphorus concentration in soils thought to be associated with storm events. The passage of Hurricane Wilma across Shark River estuary in 2005 allowed us to quantify sediment deposition and nutrient inputs in FCE mangrove forests associated with this storm event and to evaluate whether these pulsing events are sufficient to regulate nutrient biogeochemistry in mangrove forests of south Florida. We sampled the spatial pattern of sediment deposits and their chemical properties in mangrove forests along FCE sites in December 2005 and October 2006. The thickness (0.5 to 4.5 cm) of hurricane sediment deposits decreased with distance inland at each site. Bulk density, organic matter content, total nitrogen (N) and phosphorus (P) concentrations, and inorganic and organic P pools of hurricane sediment deposits differed from surface (0–10 cm) mangrove soils at each site. Vertical accretion resulting from this hurricane event was eight to 17 times greater than the annual accretion rate (0.30± 0.03 cm year−1) averaged over the last 50 years. Total P inputs from storm-derived sediments were equivalent to twice the average surface soil nutrient P density (0.19 mg cm−3). In contrast, total N inputs contributed 0.8 times the average soil nutrient N density (2.8 mg cm−3). Allochthonous mineral inputs from Hurricane Wilma represent a significant source of sediment to soil vertical accretion rates and nutrient resources in mangroves of southwestern Everglades. The gradient in total P deposition to mangrove soils from west to east direction across the FCE associated with this storm event is particularly significant to forest development due to the P-limited condition of this carbonate ecosystem. This source of P may be an important adaptation of mangrove forests in the Caribbean region to projected impacts of sea-level rise.

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Our goal was to quantify the coupled process of litter turnover and leaching as a source of nutrients and fixed carbon in oligotrophic, nutrient-limited wetlands. We conducted poisoned and non-poisoned incubations of leaf material from four different perennial wetland plants (Eleocharis spp., Cladium jamaicense, Rhizophora mangle and Spartina alterniflora) collected from different oligotrophic freshwater and estuarine wetland settings. Total phosphorus (TP) release from the P-limited Everglades plant species (Eleocharis spp., C. jamaicense and R. mangle) was much lower than TP release by the salt marsh plant S. alterniflora from N-limited North Inlet (SC). For most species and sampling times, total organic carbon (TOC) and TP leaching losses were much greater in poisoned than non-poisoned treatments, likely as a result of epiphytic microbial activity. Therefore, a substantial portion of the C and P leached from these wetland plant species was bio-available to microbial communities. Even the microbes associated with S. alterniflora from N-limited North Inlet showed indications of P-limitation early in the leaching process, as P was removed from the water column. Leaves of R. mangle released much more TOC per gram of litter than the other species, likely contributing to the greater waterborne [DOC] observed by others in the mangrove ecotone of Everglades National Park. Between the two freshwater Everglades plants, C. jamaicense leached nearly twice as much P than Eleocharis spp. In scaling this to the landscape level, our observed leaching losses combined with higher litter production of C. jamaicense compared to Eleocharis spp. resulted in a substantially greater P leaching from plant litter to the water column and epiphytic microbes. In conclusion, leaching of fresh plant litter can be an important autochthonous source of nutrients in freshwater and estuarine wetland ecosystems.

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Globally, human populations are increasing and coastal ecosystems are becoming increasingly impacted by anthropogenic stressors. As eutrophication and exploitation of coastal resources increases, primary producer response to these drivers becomes a key indicator of ecosystem stability. Despite the importance of monitoring primary producers such as seagrasses and macroalgae, detailed studies on the response of these benthic habitat components to drivers remain relatively sparse. Utilizing a multi-faceted examination of turtle-seagrass and sea urchin-macroalgae consumer and nutrient dynamics, I elucidate the impact of these drivers in Akumal, Quintana Roo, Mexico. In Yal Ku Lagoon, macroalgae bioindicators signified high nutrient availability, which is important for further studies, but did not consistently follow published trends reflecting decreased δ 15N content with distance from suspected source. In Akumal Bay, eutrophication and grazing by turtles and fishes combine to structure patches within the seagrass beds. Grazed seagrass patches had higher structural complexity and productivity than patches continually grazed by turtles and fishes. Results from this study indicate that patch abandonment may follow giving-up density theory, the first to be recorded in the marine environment. As Diadema antillarum populations recover after their massive mortality thirty years ago, the role these echinoids will have in reducing macroalgae cover and altering ecosystem state remains to be clear. Although Diadema antillarum densities within the coral reef ecosystem were comparable to other regions within the Caribbean, the echinoid population in Akumal Bay was an insufficient driver to prevent dominance of a turf-algal-sediment (TAS) state. After a four year study, declining coral cover coupled with increased algal cover suggests that the TAS-dominated state is likely to persist over time despite echinoid recovery. Studies on macroalgal diversity and nutrients within this same region of echinoids indicated diversity and nutrient content of macroalgae increased, which may further increase the persistence of the algal-dominated state. This study provides valuable insight into the variable effects of herbivores and nutrients on primary producers within a tropical coastal ecosystem. Results from this work challenge many of the currently accepted theories on primary producer response to nutrients and herbivory while providing a framework for further studies into these dynamics.

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Debate concerning bilingual education effectiveness may focus around the definition of academic language. Two aspects of such-vocabulary and grammar-were examined in 4th and 8th grade textbooks. Results showed substantial increases in the number of abstract words and complex sentences, suggesting more daunting language demands for older non-English-speaking students.

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We estimated trophic position and carbon source for three consumers (Florida gar, Lepisosteus platyrhincus; eastern mosquitofish, Gambusia holbrooki; and riverine grass shrimp, Palaemonetes paludosus) from 20 sites representing gradients of productivity and hydrological disturbance in the southern Florida Everglades, U.S.A. We characterized gross primary productivity at each site using light/dark bottle incubation and stem density of emergent vascular plants. We also documented nutrient availability as total phosphorus (TP) in floc and periphyton, and the density of small fishes. Hydrological disturbance was characterized as the time since a site was last dried and the average number of days per year the sites were inundated for the previous 10 years. Food-web attributes were estimated in both the wet and dry seasons by analysis of δ15N (trophic position) and δ13C (food-web carbon source) from 702 samples of aquatic consumers. An index of carbon source was derived from a two-member mixing model with Seminole ramshorn snails (Planorbella duryi) as a basal grazing consumer and scuds (amphipods Hyallela azteca) as a basal detritivore. Snails yielded carbon isotopic values similar to green algae and diatoms, while carbon values of scuds were similar to bulk periphyton and floc; carbon isotopic values of cyanobacteria were enriched in C13compared to all consumers examined. A carbon source similar to scuds dominated at all but one study site, and though the relative contribution of scud-like and snail-like carbon sources was variable, there was no evidence that these contributions were a function of abiotic factors or season. Gar consistently displayed the highest estimated trophic position of the consumers studied, with mosquitofish feeding at a slightly lower level, and grass shrimp feeding at the lowest level. Trophic position was not correlated with any nutrient or productivity parameter, but did increase for grass shrimp and mosquitofish as the time following droughts increased. Trophic position of Florida gar was positively correlated with emergent plant stem density.

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The primary purpose of these studies was to determine the effect of planning menus using the Institute of Medicine's (IOMs) Simple Nutrient Density Approach on nutrient intakes of long-term care (LTC) residents. In the first study, nutrient intakes of 72 subjects were assessed using Dietary Reference Intakes (DRIs) and IOM methodology. The intake distributions were used to set intake and menu planning goals. In the second study, the facility's regular menus were modified to meet the intake goals for vitamin E, magnesium, zinc, vitamin D and calcium. An experiment was used to test whether the modified menu resulted in intakes of micronutrients sufficient to achieve a low prevalence (<3%) of nutrient inadequacies. Three-day weighed food intakes for 35 females were adjusted for day-to-day variations in order to obtain an estimate of long-term average intake and to estimate the proportion of residents with inadequate nutrient intakes. ^ In the first study, the prevalence of inadequate intakes was determined to be between 65-99% for magnesium, vitamin E, and zinc. Mean usual intakes of Vitamin D and calcium were far below the Adequate Intakes (AIs). In the experimental study, the prevalence of inadequacies was reduced to <3% for zinc and vitamin E but not magnesium. The groups' mean usual intake from the modified menu met or exceeded the AI for calcium but fell short for vitamin D. Alternatively, it was determined that addition of a multivitamin and mineral (MVM) supplement to intakes of the regular menu could be used to achieve goals for vitamin E, zinc and vitamin D but not calcium and magnesium. ^ A combination of menu modification and MVM supplementation may be necessary to achieve a low prevalence of micronutrient inadequacies among LTC residents. Menus should be planned to optimize intakes of those nutrients that are low in an MVM, such as calcium, magnesium, and potassium. A MVM supplement should be provided to fill the gap for nutrients not provided in sufficient amounts by the diet, such as vitamin E and vitamin D. ^

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Knowledge of cell electronics has led to their integration to medicine either by physically interfacing electronic devices with biological systems or by using electronics for both detection and characterization of biological materials. In this dissertation, an electrical impedance sensor (EIS) was used to measure the electrode surface impedance changes from cell samples of human and environmental toxicity of nanoscale materials in 2D and 3D cell culture models. The impedimetric response of human lung fibroblasts and rainbow trout gill epithelial cells when exposed to various nanomaterials was tested to determine their kinetic effects towards the cells and to demonstrate the biosensor's ability to monitor nanotoxicity in real-time. Further, the EIS allowed rapid, real-time and multi-sample analysis creating a versatile, noninvasive tool that is able to provide quantitative information with respect to alteration in cellular function. We then extended the application of the unique capabilities of the EIS to do real-time analysis of cancer cell response to externally applied alternating electric fields at different intermediate frequencies and low-intensity. Decreases in the growth profiles of the ovarian and breast cancer cells were observed with the application of 200 and 100 kHz, respectively, indicating specific inhibitory effects on dividing cells in culture in contrast to the non-cancerous HUVECs and mammary epithelial cells. We then sought to enhance the effects of the electric field by altering the cancer cell's electronegative membrane properties with HER2 antibody functionalized nanoparticles. An Annexin V/EthD-III assay and zeta potential were performed to determine the cell death mechanism indicating apoptosis and a decrease in zeta potential with the incorporation of the nanoparticles. With more negatively charged HER2-AuNPs attached to the cancer cell membrane, the decrease in membrane potential would thus leave the cells more vulnerable to the detrimental effects of the applied electric field due to the decrease in surface charge. Therefore, by altering the cell membrane potential, one could possibly control the fate of the cell. This whole cell-based biosensor will enhance our understanding of the responsiveness of cancer cells to electric field therapy and demonstrate potential therapeutic opportunities for electric field therapy in the treatment of cancer.

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Predation, predation risk, and resource quality affect suites of prey traits that collectively impact individual fitness, population dynamics, and community structure. However, studies of multi-trophic level effects generally focus on a single prey trait, failing to capture trade-offs among suites of covarying traits that govern population responses and emergent community patterns. We used structural equation models (SEM) to summarize the non-lethal and lethal effects of crayfish, Procambarus fallax, and phosphorus (P) addition, which affected prey food quality (periphyton), on the interactive effects of behavioral, morphological, developmental, and reproductive traits of snails, Planorbella duryi. Univariate and multivariate analyses suggested trade-offs between production (growth, reproduction) and defense (foraging behavior, shell shape) traits of snails in response to non-lethal crayfish and P addition, but few lethal effects. SEM revealed that non-lethal crayfish effects indirectly limited per capita offspring standing stock by increasing refuge use, slowing individual growth, and inducing snails to produce thicker, compressed shells. The negative effects of non-lethal crayfish on snails were strongest with P addition; snails increased allocation to shell defense rather than growth or reproduction. However, compared to ambient conditions, P addition with non-lethal crayfish still yielded greater per capita offspring standing stock by speeding individual snail growth enabling them to produce more offspring that also grew faster. Increased refuge use in response to non-lethal crayfish led to a non-lethal trophic cascade that altered the spatial distribution of periphyton. Independent of crayfish effects, snails stimulated periphyton growth through nutrient regeneration. These findings illustrate the importance of studying suites of traits that reveal costs associated with inducing different traits and how expressing those traits impacts population and community level processes.

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Television (TV) reaches more people than any other medium which makes it an important source of health information. Since TV ads often offer information obliquely, this study investigated implied health messages found in food and nutrition TV ads. The goals were to determine the proportion of food and nutrition ads among all TV advertising and to use content analysis to identify their implied messages and health claims. A randomly selected sample of TV ads were collected over a 28-day period beginning May 8, 1987. The sample contained 3547 ads; 725 (20%) were food-related. All were analyzed. About 10% of food-related TV ads contained a health claim. Twenty-five representative ads of the 725 food ads were also reviewed by 10 dietitians to test the reliability of the instrument. Although the dietitians agreed upon whether a health claim existed in a televised food ad, their agreement was poor when evaluating the accuracy of the claim. The number of food-related ads dropped significantly on Saturday, but the number of alcohol ads rose sharply on Saturday and Sunday. Snack ads were shown more often on Thursday, but snack commercials were also numerous on Saturday morning and afternoon, as were cereal ads. Ads for snack foods accounted for the greatest proportion of ads (20%) while fast food accounted for only 7%. Alcohol constituted about 9% of all food and nutrition ads.

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The chemical composition of organic matter (Corg, Norg, d13C, d1SN, and n-alkanes) was studied in the top layer of bottom sediments of the East Siberian Sea. Possible ways were proposed to estimate the amount of the terrigenous component in their organic matter (OM). The fraction of terrigenous OM estimated by the combined use of genetic indicators varied from 15% in the eastern part of the sea, near the Long Strait, to 95% in the estuaries of the Indigirka and Kolyma rivers, averaging 62% over the sea area.

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A 100 cm long sediment sequence was recovered from Beaver Lake in Amery Oasis, East Antarctica, using gravity and piston corers. Sedimentological and mineralogical analyses and the absence of micro and macrofossils indicate that the sediments at the base of the sequence formed under glacial conditions, probably prior to c. 12 500 cal. yr BP. The sediments between c. 81 and 31 cm depth probably formed under subaerial conditions, indicating that isostatic uplift since deglaciation has been substantially less than eustatic sea-level rise and that large areas of the present-day floor of Beaver Lake must have been subaerially exposed following deglaciation. The upper 31 cm of the sediment sequence were deposited under glaciomarine conditions similar to those of today, supporting geomorphic observations that the Holocene was a period of relative sea-level highstand in Amery Oasis.

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The Sea of Okhotsk is a marginal sea of the Pacific Ocean, which is characterized by strong variations in the productivity and sediment supply due to sea ice transport and river input. Furthermore the variations in the hydrological cycle determine the formation of the SOIW (Sea of Okhotsk Intermediate Water) which plays an important role in the ventilation processes in the intermediate water of the N-Pacific. Isotope data measured on planktonic and benthic foraminifera, sedimentological and geochemical studies of sediment cores and surface samples from the Sea of Okhotsk are used to reconstruct the paleoceanography during the past 350.000 years. The dating and correlation of the sediments are based on oxygen isotope stratigraphy, absolute ages, magnetic susceptibility as well as a detailled tephrachronology of the entire basin. The sedimentation rates are characterized by temporal and spatial variations. The maximum sedimentation rate takes place at the continental slope off Sakhalin due to the input of the Amur River, the sea ice drift and the high productivity. The sedimentation rate in the eastern part of the Sea of Okhotsk is generelly high because of the influence of the nutrient-rich Kamchatka Current. In the central and northern parts of the Sea of Okhotsk, areas with low productivity and reduced terrestrial supply, the sedimentation rate is the lowest. The analyses of the surface sediment samples make it possible to characterize the (sub)- recent sediment supply and transportation processes. The bulk sediment measurements, isotope data and the accumulation rate of ice-rafted debris (IRD) show a dominant sea ice cover and a region with a high productivity as well as a high Amur River input in the western part of the sea. The eastern part of the Sea of Okhotsk, however, is marked by the predominance of warm and nutrient-rich water masses coming from the Kamchatka Current which restricts the sea ice cover. This is reflected in low content of ice-rafted debris and high productivity proxies as well as in isotope data. The deposits of the Sea of Okhotsk are characterized by terrestrial, biogenic and volcanogenic sediment input which varies temporally and spatially. Here, the sedimentation pattern is dominated by the terrestrial input. Bulk sediment measurements and sample analyses of the > 63 micron particle input make it possible to distinguish glacial and interglacial fluctuations. The sedimentation processes during glacial times are determined by a high content of ice-rafted debris, whereas the primary production is higher during interglacial periods. During the last glacial/interglacial cycle the IRD-distribution pattern indicates a strong sea ice transport in the western part and in large areas of the open sea in the eastern part of the Sea of Okhotsk with a relatively constant ice-drift system. The IRD flux in sediments of the oxygen isotope Stage 6 reflects a new sedimentation pattern in the eastern part of the sea. This high IRD accumulation rate indicates ice advances beyond the shelf margin and an iceberg transport from NE-E direction into the Sea of Okhotsk. The several large, brief, negative anomalies in d13C values of Neogloboquadrina pachyderma (s) show releases of methane from basin sediments which correspond to periods of relative sea level falls. The high sedimentation rates on the Sakhalin slope allow insights into the climatic history in Holocene and indicate shorter-scale variations oscillation in Stage 3, which correlate with the global climatic changes. These variations are described as Dansgaard-Oeschger cycles in Greenland ice cores and as Heinrich-Events in several marine sediment cores from the N-Atlantic.