913 resultados para Small agrarian production


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Macroalgae, in particular kelps, produce a large amount of biomass in Kongsfjorden, which is to a great extent released into the water in an annual cycle. As an example, the brown alga Alaria esculenta loses its blade gradually, 3 ± 0.8 % of the blade area per day (August 2012), thereby adding to the pool of particulate organic matter (POM) in the fjord. Upon release small thallus pieces are "aging" in that they are prone to leaching and serving as substrate for microorganisms, thus turning into palatable food for suspension and bottom feeders. In order to define a macroalgal baseline for the Kongsfjorden food web, stable isotopes d14C and d15N were measured in individuals of A. esculenta, Saccharina latissima and Laminaria digitata directly sampled after collection and in artificially produced POM (aPOM) of A. esculenta that was allowed to age under experimental conditions. In aPOM from this species sampled in August 2012 the C/N ratios decreased between d1 and d8 of a 14-day culture period in parallel to the fading photosynthetic activity of the algal fragments as demonstrated by use of an Imaging-PAM. Microscopic observations of the aPOM in August 2012 and 2013 revealed the frequent occurrence of small brown algal endo- and epiphytes. First feeding experiments with Mysis oculata (Mysids) and Hiatella arctica (Bivalves) showed that these species can ingest macroalgal POM. The importance of kelp-derived POM for the food web is subject of the current research.

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The SES_UNLUATA_GR1-Mesozooplankton faecal pellet production rates dataset is based on samples taken during March and April 2008 in the Northern Libyan Sea, Southern Aegean Sea and in the North-Eastern Aegean Sea. Mesozooplankton is collected by vertical tows within the 0-100 m layer or within the Black sea water body mass layer in the case of the NE Aegean, using a WP-2 200 µm net equipped with a large non-filtering cod-end (10 l). Macrozooplankton organisms are removed using a 2000 µm net. A few unsorted animals (approximately 100) are placed inside several glass beaker of 250 ml filled with GF/F or 0.2 µm Nucleopore filtered seawater and with a 100 µm net placed 1 cm above the beaker bottom. Beakers are then placed in an incubator at natural light and maintaining the in situ temperature. After 1 hour pellets are separated from animals and placed in separated flasks and preserved with formalin. Pellets and are counted and measured using an inverted microscope. Animals are scanned and counted using an image analysis system. Carbon- Specific faecal pellet production is calculated from a) faecal pellet production, b) individual carbon: Animals are scanned and their body area is measured using an image analysis system. Body volume is then calculated as an ellipsoid using the major and minor axis of an ellipse of same area as the body. Individual carbon is calculated from a carbon- total body volume of organisms (relationship obtained for the Mediterranean Sea by Alcaraz et al. (2003) divided by the total number of individuals scanned and c) faecal pellet carbon: Faecal pellet length and width is measured using an inverted microscope. Faecal pellet volume is calculated from length and width assuming cylindrical shape. Conversion of faecal pellet volume to carbon is done using values obtained in the Mediterranean from: a) faecal pellet density 1,29 g cm**3 (or pg µm**3) from Komar et al. (1981); b) faecal pellet DW/WW=0,23 from Elder and Fowler (1977) and c) faecal pellet C%DW=25,5 Marty et al. (1994).

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The SES_GR2-Mesozooplankton faecal pellet production rates dataset is based on samples taken during August and September 2008 in the Northern Libyan Sea, Southern Aegean Sea and the North-Eastern Aegean Sea. Mesozooplankton is collected by vertical tows within the 0-100 m layer or within the Black sea water body mass layer in the case of the NE Aegean, using a WP-2 200 µm net equipped with a large non-filtering cod-end (10 l). Macrozooplankton organisms are removed using a 2000 µm net. A few unsorted animals (approximately 100) are placed inside several glass beaker of 250 ml filled with GF/F or 0.2 µm Nucleopore filtered seawater and with a 100 µm net placed 1 cm above the beaker bottom. Beakers are then placed in an incubator at natural light and maintaining the in situ temperature. After 1 hour pellets are separated from animals and placed in separated flasks and preserved with formalin. Pellets are counted and measured using an inverted microscope. Animals are scanned and counted using an image analysis system. Carbon- Specific faecal pellet production is calculated from a) faecal pellet production, b) individual carbon: Animals are scanned and their body area is measured using an image analysis system. Body volume is then calculated as an ellipsoid using the major and minor axis of an ellipse of same area as the body. Individual carbon is calculated from a carbon- total body volume of organisms (relationship obtained for the Mediterranean Sea by Alcaraz et al. (2003) divided by the total number of individuals scanned and c) faecal pellet carbon: Faecal pellet length and width is measured using an inverted microscope. Faecal pellet volume is calculated from length and width assuming cylindrical shape. Conversion of faecal pellet volume to carbon is done using values obtained in the Mediterranean from: a) faecal pellet density 1,29 g cm**3 (or pg µm**3) from Komar et al. (1981); b) faecal pellet DW/WW=0,23 from Elder and Fowler (1977) and c) faecal pellet C%DW=25,5 Marty et al. (1994).

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The SES_GR1-Mesozooplankton faecal pellet production rates dataset is based on samples taken during April 2008 in the North-Eastern Aegean Sea. Mesozooplankton is collected by vertical tows within the Black sea water body mass layer in the NE Aegean, using a WP-2 200 µm net equipped with a large non-filtering cod-end (10 l). Macrozooplankton organisms are removed using a 2000 µm net. A few unsorted animals (approximately 100) are placed inside several glass beaker of 250 ml filled with GF/F or 0.2 µm Nucleopore filtered seawater and with a 100 µm net placed 1 cm above the beaker bottom. Beakers are then placed in an incubator at natural light and maintaining the in situ temperature. After 1 hour pellets are separated from animals and placed in separated flasks and preserved with formalin. Pellets are counted and measured using an inverted microscope. Animals are scanned and counted using an image analysis system. Carbon- Specific faecal pellet production is calculated from a) faecal pellet production, b) individual carbon: Animals are scanned and their body area is measured using an image analysis system. Body volume is then calculated as an ellipsoid using the major and minor axis of an ellipse of same area as the body. Individual carbon is calculated from a carbon- total body volume of organisms (relationship obtained for the Mediterranean Sea by Alcaraz et al. (2003) divided by the total number of individuals scanned and c) faecal pellet carbon: Faecal pellet length and width is measured using an inverted microscope. Faecal pellet volume is calculated from length and width assuming cylindrical shape. Conversion of faecal pellet volume to carbon is done using values obtained in the Mediterranean from: a) faecal pellet density 1,29 g cm**3 (or pg µm**3) from Komar et al. (1981); b) faecal pellet DW/WW=0,23 from Elder and Fowler (1977) and c) faecal pellet C%DW=25,5 Marty et al. (1994).

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Production, oxygen uptake, and sinking velocity of copepod fecal pellets egested by Temora longicornis were measured using a nanoflagellate (Rhodomonas sp.), a diatom (Thalassiosira weissflogii), or a coccolithophorid (Emiliania huxleyi) as food sources. Fecal pellet production varied between 0.8 pellets ind**-1 h**-1 and 3.8 pellets ind**-1 h**-1 and was significantly higher with T. weissflogii than with the other food sources. Average pellet size varied between 2.2 x 10**5 µm**3 and 10.0 x 10**5 µm**3. Using an oxygen microsensor, small-scale oxygen fluxes and microbial respiration rates were measured directly with a spatial resolution of 2 µm at the interface of copepod fecal pellets and the surrounding water. Averaged volume-specific respiration rates were 4.12 fmol O2 µm**-3 d**-1, 2.86 fmol O2 µm**-3 d**-1, and 0.73 fmol O2 µm**-3 d**-1 in pellets produced on Rhodomonas sp., T. weissflogii, and E. huxleyi, respectively. The average carbon-specific respiration rate was 0.15 d**-1 independent on diet (range: 0.08-0.21 d**-1). Because of ballasting of opal and calcite, sinking velocities were significantly higher for pellets produced on T. weissflogii (322 +- 169 m d**-1) and E. huxleyi (200 +- 93 m d**-1) than on Rhodomonas sp. (35 +- 29 m d**-1). Preservation of carbon was estimated to be approximately 10-fold higher in fecal pellets produced when T. longicornis was fed E. huxleyi or T. weissflogii rather than Rhodomonas sp. Our study directly demonstrates that ballast increases the sinking rate of freshly produced copepod fecal pellets but does not protect them from decomposition.

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Providing price incentives to farmers is usually considered essential for agricultural development. Although such incentives are important, regarding price as the sole explanatory factor is far from satisfactory in understanding the complex realities of agricultural production in Africa. By analyzing the share contracts widely practiced in Ghana, this article argues that local institutions such as land tenure systems and agrarian contracts provide strong incentives and disincentives for agricultural production. Based on data derived from fieldwork in the 1990s, the study analyzes two types of share contracts and the incentive structures embedded in them. The analysis reveals that farmers' investment behavior needs to be understood in terms of both short-term incentive to increase yield and long-term incentive to strengthen land rights. The study concludes that the role of price incentives in agricultural production needs to be reconsidered by placing it in wider incentive structures embedded in local institutions.

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This study examines the effects of intra-regional cooperation among firms and institutions on the growth of firms, using the unique data set of questionnaire survey collected in the three major industrial clusters in Japan. In contrast to the existing studies on regional innovations or agglomeration economies, this study explicitly focuses on the detailed contents of cooperative activities with two specific viewpoints: 1) the contents of regional cooperation in each of the three production stages of R&D, commercialization, and marketing, and 2) the detailed types of alliance partners. Our results demonstrate three points: 1) positive correlations are observed between the intensity of regional cooperation and the firm growth rate and R&D expenditure, 2) horizontal cooperation such as alliances with universities and cross-industry exchange organizations has positive significant effects on the growth rate of firms, which is in contrast with the previous studies that stressed only the role of vertically integrated inter-firm linkages in Japan, and 3) contents and partners of regional cooperation are different among the three clusters based on different dominant industries.

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In this paper, we explore the firm-level impacts of flooding in Thailand in 2011, specifically those on the procurement patterns at Japanese affiliates in Thailand. Our findings are as follow. First, the damaged small firms are more likely to lower their local procurement share, particularly the share of procurement from other Japanese-owned firms in Thailand. Second, damaged young firms and damaged old firms are more likely to raise the shares of imports from Japan and China, respectively. Third, there are no impacts on imports from ASEAN and other countries. These findings are useful for uncovering how multinational firms adjust their production networks before and after natural disasters.

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Aquaponics is the science of integrating intensive fish aquaculture with plant production in recirculating water systems. Although ion waste production by fish cannot satisfy all plant requirements, less is known about the relationship between total feed provided for fish and the production of milliequivalents (mEq) of different macronutrients for plants, especially for nutrient flow hydroponics used for strawberry production in Spain. That knowledge is essential to consider the amount of macronutrients available in aquaculture systems so that farmers can estimate how much nutrient needs to be supplemented in the waste water from fish, to produce viable plant growth. In the present experiment, tilapia (Oreochromis niloticus L.) were grown in a small-scale recirculating system at two different densities while growth and feed consumption were noted every week for five weeks. At the same time points, water samples were taken to measure pH, EC25, HCO3 – , Cl – , NH4 + , NO2 – , NO3 – , H2PO4 – , SO4 2– , Na + , K+ , Ca 2+ and Mg 2+ build up. The total increase in mEq of each ion per kg of feed provided to the fish was highest for NO3 - , followed, in decreasing order, by Ca 2+ , H2PO4 – , K+ , Mg 2+ and SO4 2– . The total amount of feed required per mEq ranged from 1.61- 13.1 kg for the four most abundant ions (NO3 – , Ca 2+ , H2PO4 – and K+ ) at a density of 2 kg fish m–3 , suggesting that it would be rather easy to maintain small populations of fish to reduce the cost of hydroponic solution supplementation for strawberries.

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Soft-rot Enterobacteriaceae (SRE), which belong to the genera Pectobacterium and Dickeya, consist mainly of broad host-range pathogens that cause wilt, rot, and blackleg diseases on a wide range of plants. They are found in plants, insects, soil, and water in agricultural regions worldwide. SRE encode all six known protein secretion systems present in gram-negative bacteria, and these systems are involved in attacking host plants and competing bacteria. They also produce and detect multiple types of small molecules to coordinate pathogenesis, modify the plant environment, attack competing microbes, and perhaps to attract insect vectors. This review integrates new information about the role protein secretion and detection and production of ions and small molecules play in soft-rot pathogenicity.

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In order to complement ISFOC’s characterization capabilities, a Helios 3198 CPV Solar Simulator was installed in summer 2010. This Solar Simulator, based on a parabolic mirror and a high-intensity, small area Xenon flash lamp was developed by the Instituto de Energía Solar in Madrid [1] and is manufactured and distributed by Soldaduras Avanzadas [2]. This simulator is used not only for R&D purposes, but as a quality control tool for incoming modules that are to be installed in ISFOC’s CPV plants. In this paper we will discuss the results of recent measurements of close to 5000 modules, the entire production of modules corresponding to a small CPV power plant (200 kWp). We scrutinize the resultant data for signs of drift in the measurements, and analyze the light quality before and after, to check for changes in spectrum or spatial uniformity.)

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The real increase in energy prices and the intention of reducing pollutant emissions in developed countries makes interesting to use solar energy in all the processes where its application is possible. As it is demonstrated in countries sited at latitudes with optimal conditions of solar radiation and temperature, it is possible to use solar energy as heat source for small-scale hatchery [1,2], but beyond, making a design for proper installation; it is possible to use solar energy as main or support energy source in medium and large size incubators . Monitoring of a normal actual process using temperature and relative humidity sensors is necessary to know the actual operating conditions that the solar heating system must be designed and sized for. Moreover, the identification and analysis of temperature and enthalpy gradients inside the incubator is of major importance.

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Small family farm in mountain areas can found in horticulture one alternative to increase incomes. Horticulture crop required more labour and increased the land intensification. Market of production will be the key factor in the future of this family farms.

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In the last years, intensive animal husbandry production has led to a large concentration of animals in small areas. This has resulted in the production of excessive amounts of manures with insufficient nearby land for application. One of this areas is the Amblés Valley located in the centre of Spain, near to Ávila city, with an extension of 167472 ha of which 88.9% is agricultural land. This valley has an important livestock focused on pig, cattle, chicken production which is associated with the generation of more than 200,000 t/year of manure. There are a number of environmental problems associated with these intensive agricultural systems, including N and P pollution of water bodies, methane emissions and odour pollution. These serious environmental threats are called for innovative environmental management approaches. A feasible technology for the management of manures, offering a potential to valorise these wastes, is pyrolysis, which results in the production of biochar. The objective of this work is evaluated the technical and economic feasibility of the production of biochar in Amblés Valley (Spain).