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النتائج 71 - 80 من 89
Foraging behaviour of the social caterpillar Eutachyptera psidii (Sallé) (Lepidoptera: Lasiocampidae) during a prolonged period of food and water deprivation النص الكامل
2008
Fitzgerald, Terrence D. | PESCADOR-RUBIO, ALFONSO | Isaacs, Gary
1. Colonies of the social caterpillar Eutachyptera psidii (Sallé) (Hymenoptera: Lasiocampidae) occurring on oak (Quercus) in upland forests of Mexico endure periods as long as 6 weeks, with little or no food or water between the time host trees shed their leaves in April and produce new leaves in June. 2. By monitoring the activity of both field and laboratory colonies with infrared activity monitors and data loggers, it was found that although colonies remain active during the period of deprivation, their foraging activity shifts from once nightly when food is available to once every second night when food-deprived. 3. Over a period of absolute food and water deprivation of 18 days, caterpillars lost an average of 36% of their initial mass but none perished. On average, the caterpillars regained their pre-starvation mass within a few days after food was provided and continued to grow thereafter. During the period of starvation, caterpillars were observed to chew on dead and dried leaves in the field and on sheets of paper in the laboratory. 4. To the authors' knowledge, there is no other documented instance of a species of caterpillar that exhibits the physiological capacity to engage in a similar level of persistent activity when forced to endure a prolonged period with neither food nor water.
اظهر المزيد [+] اقل [-]Quesungual Slash & Mulch Agroforestry System (QSMAS): Improving crop water productivity food security and resource quality in the sub-humid tropics
2008
Castro, A. | Rivera, M. | Ferreira, Oscar | Pavon, Jellin | García, E. | Amézquita Collazos, Edgar | Ayarza, Miguel Angel | Barrios, E. | Rondón, Marco Antonio | Pauli, N. | Baltodano, Maria Eugenia | Mendoza, B. | Welchez, L.A. | Johnson, Nancy L. | Rubiano, J. | Cook, Simon E. | Rao, Idupulapati M.
The use of nutrient reduction and food-web management to improve water quality in the deep stratifying Wupper Reservoir, Germany النص الكامل
2008
Schärf, Wilfried
Only a combination of nutrient load abatement and food-web management proved efficient for the management of water quality in the deep stratifying Wupper Reservoir. Reduction of nutrient loading, was completed in winter 1992/1993, but resulted only in reduced winter/spring mixing of phosphorus concentrations. Since the capacity of the diatom spring bloom to remove nutrients from the trophogenic layer of this slightly eutrophic water-body was never exhausted, the surplus of total phosphorus available to support summer algal growth remained unchanged. Thus, nutrient reduction alone did not improve the water quality, as expected. Subsequent replacement of the smaller Daphnia cucullata by the larger Daphnia galeata-hyalina complex that was attributable to successful food-web management did, however, result in a shift from a turbid to a clear water regime in 1999. Clearly, the zooplankton community, and therefore food-web structure, played an integral role in nutrient recycling and in the repartitioning of the phosphorus pool. As diatom settling and grazing became much more tightly linked with the appearance of the larger-bodied Daphnia galeata-hyalina complex, which exploits lower-level food resources as early as May, daphnids increasingly acted as a sink for phosphorus. This increased export fluxes out of the pelagic zone and leaves a smaller surplus of total phosphorus to support the accumulation of summer algae. Consequently, water transparency and total chlorophyll concentrations in summer improved with food-web restructuring, indicating real oligotrophication of Wupper Reservoir driven by internal feedbacks.
اظهر المزيد [+] اقل [-]Young agriculturists [Christopher Cruz of Hagonoy, Bulacan and Ace Limpin of San Fernando City, Pampanga, Philippines] use Nova Pure PCM Agua [a product of Novatech Agri-Food Industries, bio-organic fertilizer] for lablab production
2008
Pablico, S.Ma.
Food Production and Water Conservation in a Recirculating Aquaponic System in Saudi Arabia at Different Ratios of Fish Feed to Plants النص الكامل
2008
Al-Hafedh, Yousef S. | Alam, Aftab | Beltagi, Mohamed Salaheldin
An indoor aquaponic system (i.e., the integration of fish culture with hydroponic plant production in a recirculating setup) was operated for maximizing water reuse and year-round intensive food production (Nile tilapia, Oreochromis niloticus, and leaf lettuce) at different fish feed to plants ratios. The system consisted of a fish culture component, solid removal component, and hydroponic component comprising six long channels with floating styrofoam rafts for holding plants. Fish culture effluents flowed by gravity from the fish culture component to the solid removal component and then to the hydroponic component. Effluents were collected in a sump from which a 1-horsepower in-line pump recirculated the water back to the fish culture tanks at a rate of about 250 L/min. The hydroponic component performed as biofilter and effectively managed the water quality. Fish production was staggered to harvest one of the four fish tanks at regular intervals when fish attained a minimum weight of 250 g. Out of the total eight harvests in 13 mo, net fish production per harvest averaged 33.5 kg/m³ of water with an overall water consumption of 320 L/kg of fish produced along with the production of leaf lettuce at 42 heads/m² of hydroponic surface area. Only 1.4% of the total system water was added daily to compensate the evaporation and transpiration losses. A ratio of 56 g fish feed/m² of hydroponic surface effectively controlled nutrient buildup in the effluents. However, plant density could be decreased from 42 to 25-30 plants/m² to produce a better quality lettuce.
اظهر المزيد [+] اقل [-]Desempenho de frangos de corte sob suplementação com ácidos lático, fórmico, acético e fosfórico no alimento ou na água النص الكامل
2008
Viola, Eduardo Spillari(UFRGS Programa de Pós-Graduação em Zootecnia) | Vieira, Sergio Luiz(UFRGS Departamento de Zootecnia) | Torres, Cibele Araújo(UFRGS Programa de Pós-Graduação em Zootecnia) | Freitas, Dimitri Moreira de(UFRGS) | Berres, Josemar(UFRGS Programa de Pós-Graduação em Zootecnia)
Este estudo foi realizado para avaliar os efeitos da suplementação de ácidos orgânicos nas dietas e de ácidos orgânicos e ácido ortofosfórico na água de bebida sobre o desempenho de frangos de corte. Foram utilizadas 2.112 aves divididas em seis tratamentos, cada um com oito repetições. As dietas, exclusivamente vegetais, foram formuladas à base de milho e farelo de soja sem antibióticos ou anticoccidianos. A dieta controle não foi suplementada com ácidos orgânicos. As demais foram suplementadas com misturas de ácidos orgânicos, formuladas para cada fase de crescimento (1 a 7, 8 a 21 e 22 a 35 dias de idade): mistura A: ácidos lático (52%), fórmico (1%) e acético (2%); mistura B: ácidos lático (76%), fórmico (2%) e acético (4%); mistura C: ácidos lático (50%), fórmico (8%) e acético (7%); mistura D: ácido fórmico (85%). A mistura E continha 40% de ácido lático, 5% de ácido acético e 5% de ácido ortofosfórico e foi adicionada à água de bebida. As doses adicionadas nas dietas, por fase, foram: 8,0; 4,5 e 2,5 kg/t para as misturas A, B e C e 2,5; 2,5 e 2,0 kg/t para a mistura D. A mistura E foi utilizada na água de bebida nas doses de 3,0; 2,0; 1,0 kg/1.000 L. O experimento foi conduzido em delineamento completamente casualizado. Houve um benefício geral da suplementação da mistura de ácidos sobre o ganho de peso das aves. Entretanto, não houve diferença na conversão alimentar ao final do estudo. O consumo de alimento foi menor para a mistura B, enquanto o consumo de água foi negativamente afetado pela mistura E fornecida na água. O peso relativo das seções do intestino delgado aos 7 dias de idade foi menor nas aves da dieta controle, enquanto, aos 21 dias de idade, foi menor nas aves alimentadas com a dieta suplementada com as misturas A e C. A mistura E utilizada na água determinou redução no comprimento de jejuno aos 7 dias de idade, enquanto a mistura B teve efeito negativo sobre os comprimentos de íleo e intestino delgado aos 21 dias de idade. Em comparação à dieta controle, sem suplementação de antibióticos promotores de crescimento, as dietas suplementadas com acidificantes foram eficientes em melhorar o ganho de peso de frangos de corte. | This study was carried out to evaluate the effect of the supplementation of organic acids in the diets and ortho-phosphoric acid in the drinking water on broiler performance. A total of 2,112 broiler chicks was allotted to six treatments, each one with eight replications. The diets, all vegetable, were composed by corn-soybean meal without antibiotic growth promoters or anticoccidials. A control diet did not have organic acids, whereas the other treatments had supplementation of organic acid blends as follow for the feeding phases from 1 to 7, 8 to 21, and 22 to 35 days of age: blend A: lactic acid (52%), formic (1%) and acetic (2%); blend B: lactic acid (76%), formic (2%) and acetic (4%); blend C: lactic acid (50%), formic (8%) and acetic (7%); blend D: formic acid (85%). Blend E contained 40% of lactic acid, 5% of acetic acid and 5% of ortho-phosphoric and was added to drink water. The added doses in diets, for phase, were: 8.0, 4.5, and 2.5 kg/t for blends A, B and C and 2.5, 2.5, and 2.0 kg/t for blend D. Blend E was used in drink water in doses of 3.0, 2.0, and 1.0 kg/1,000 L. A completely randomized design was used. There was a general benefit of the supplementation of the organic acid blend on weight gain of birds. However, no difference was observed for feed conversion at the end of the study. Feed intake was lower for birds fed blend B, whereas water intake was reduced by the blend E added to the drinking water. Relative weight of small intestines sections at 7 days of age was smaller in the birds on the control diet, while at the 21 days of age, was smaller in the birds supplemented with blends A and C. The blend E used in the water determined a reduction in the jejunum length at 7 days of age, while blend B had negative effects on the ileum and small intestine lengths at 21 days of age. In comparison to the control diet, without supplementation of growth promoters antibiotics, the diets supplemented with organic acids were efficient in improving the weight gain of broilers.
اظهر المزيد [+] اقل [-]Níveis de nitrogênio e fósforo na água de tanques de cultivo de tilápia vermelha submetidas a diferentes manejos alimentares النص الكامل
2008
Ana Eliza Baccarin | Célia Maria Dóra Frascá-Scorvo | Paulo Fernando Colheirinhas Novato
O experimento foi conduzido em nove tanques, de 42 m2 cada, durante sete meses. Foram utilizados machos revertidos de tilápia vermelha com peso médio inicial de 290,64 ± 5,84g, numa densidade de dois peixes/m2, para avaliar o efeito de diferentes manejos alimentares (manual, self feeding e mecânica) sobre a concentração de fósforo (P) e nitrogênio (N) na água. A ração continha 28% de proteína e 3000kcal de energia bruta por kg de ração. O delineamento foi inteiramente casualizado, num esquema de parcela subdividida no tempo com três tratamentos, oito avaliações no tempo e três repetições. As médias foram comparadas usando-se teste de Tukey. A temperatura foi aferida diariamente e, mensalmente foram aferidos nutrientes e tempo de residência da água. O fluxo inicial de água foi de 0,235 l/s, sendo reduzida a 0,133 l/s, com tempo de residência de 1,88 e 3,33 dias, respectivamente. A temperatura variou de 18 a 24,67ºC. Foram obtidas concentrações de nitrato de 59,12 a 1087,72 µg/l; nitrito: 0,08 a 39,53 µg/l; amônia ionizada: 0 a 520,95 µg/l; fósforo total: 2,87 a 74,74 µg/l e ortofosfato: 0 a 23,79 µg/l. Os diferentes manejos alimentares não influenciaram a qualidade da água
اظهر المزيد [+] اقل [-]Comparison of the BAX System PCR Method to Brazil's Official Method for the Detection of Salmonella in Food, Water, and Environmental Samples
2008
Tomazelli, Ingrid Boesche | Freitas, Josinete Barros de | Fabbi, Leania Maria | Filipini, Terezinha Agnese | Silva, Claudia Maria da | Bedin, Janaina Mussnich | Duarte, Dalila Angelica Moliterno | Santos, Amaury dos | Baccarin, Aldo | Higa, Ligia Rossi Garcia | Yano, Dirce Mithico Yamaoka | Killner, Mario | Frezza, Andrea Leao Cameiro | Abecia, Eduardo Carlos de Gosztonyi | Tronco, Vania Maria | Tomazelli Junior, Osmar
A two-stage study compared the BAX system PCR method with the reference culture method used by the Brazilian Ministry of Agriculture and Food Supply for the detection of Salmonella in food, water, and environmental samples. In stage 1, fish matrix samples (n = 258) were spiked at several levels with Salmonella and a combination of Salmonella and non-Salmonella competitive organisms. Replicates were analyzed by the BAX system PCR method and the reference method with comparable results (sensitivity >or=97.5%, specificity >or=83.3%) from both methods at the limit of detection. In stage 2, a total of 1,988 samples with 70 product types were analyzed with both methods. Five laboratories were involved in this study, and the samples used were from routine analyses. The BAX system PCR method was shown to be comparable to the reference method, with a limit of detection of 1.0 to 2.0 CFU/25 g of sample. Analysis of the results obtained in stage 2 and in the combination of stages 1 and 2 for the BAX system showed the following performance: sensitivity >or=99.0%, specificity >or=97.2%, false-negative rate <or=1.1%, and false-positive rate <or= 2.8%. Therefore, the BAX system appears to be equivalent to the reference method, with >or=97.3% agreement.
اظهر المزيد [+] اقل [-]Seminar on Drinking Water and Food Security in Hard Rock Areas through Optimum Use of Groundwater, Rainwater Harvesting and Crop-water Planning with special reference to Gadag District, Karnataka, April 29-30, 2008 at Hulkoti
2008
Papers presented in a seminar held at Hulkoti during 29-30 April 2008.
اظهر المزيد [+] اقل [-]Assessment of global biomass potentials and their links to food, water, biodiversity, energy demand and economy: Inventory and analysis of existing studies. Supporting document
2008
Dornburg, V. | Faaij, A. | Verweij, P. | Langeveld, H. | Ven, van de, G.W.J. | Wester, P. | Keulen, van, H. | Diepen, van, K. | Meeusen, M.J.G. | Banse, M.A.H. | Ros, J. | Vuuren, van, D. | Born, van den, G.J. | Oorschot, van, M. | Smout, F. | Vliet, van, J.M. | Aiking, H. | Londo, M. | Mozaffarian, H. | Smekens, H.
This Supporting Document contains the result of the inventory phase of the study: ¿Biomass Assessment: Assessment of global biomass potentials and their links to food, water, biodiversity, energy demand and materials¿. The study was commissioned and supported by the Netherlands Research Program on Climate Change (NRP-CC), subprogram Scientific Assessment and Policy Analysis (WAB).
اظهر المزيد [+] اقل [-]