900 resultados para Salt marsh and semi-arid
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This study seeks to evaluate how enterorganizational and interpersonal trust affects the degree of State interference in the operations of public-nonprofit partnerships (PNPs). We conducted a qualitative case study in two Brazilian PNPs, Projeto Guri and Orquestra Sinfônica do Estado de São Paulo, through documental analysis and semi-structured interviews. Content analysis of the data yielded a trust framework that begins to explain how a variety of factors, including the protective qualities of the management contract and the strength of the board, moderate the relationship between interpersonal and interorganizational trust in PNPs. The study reveals that unlike Zaheer et al (1998), interpersonal trust had a unique and prominent effect on State interference and types of collaboration in PNPs. Parting from the suggestions by previous authors to contextualize PNP literature findings, the framework takes into account the highly personalistic qualities of Brazilian culture as well as historical and institutional context while highlighting the crucial role of interpersonal trust in Brazilian PNPs.
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Este trabalho teve por objetivo estudar a viabilidade econômica da produção consorciada de cacau e banana na região do Perímetro Irrigado Tabuleiro de São Bernardo nos municípios de Magalhães de Almeida e Araioses, estado do Maranhão (MA), tendo em vista a ampla disponibilidade de recursos naturais para o cultivo e a potencialidade de ser uma região de escape das principais doenças que afetam as culturas de cacau e banana. O trabalho verifica a oportunidade de negócio de produção de cacau e banana na região do rio Parnaíba. O estudo utiliza projeções de fluxo de caixa e os desconta para o Valor Presente Líquido (VPL) para aferir a viabilidade econômica do negócio de produção de cacaueiro e bananeira nesta região do Brasil. Foram realizadas pesquisas bibliográficas para analisar as características edafoclimáticas da microrregião, as características fisiológicas do cacaueiro e seu consórcio com a bananeira para o sombreamento temporário necessário durante a fase de crescimento do cacaueiro. Foi sugerido o pacote de alta tecnologia para a produção de cacaueiro, dada a necessidade de irrigação para o seu cultivo. Diferentes produtividades e preços de cacau e banana foram utilizados para analisar a sensibilidade económica deste negócio. Ao projetar um fluxo de caixa, foi possível fazer uma análise sobre o negócio, viabilidade e riscos. Deve-se notar que não há grandes áreas produtoras de cacau na região do rio Parnaíba. Porém, há pequenas áreas de cacau em regiões semiáridas (ou de cerrado). Assim, a produção vegetal carece de comprovação de produção em larga escala para atestar de modo prático algumas das premissas econômico-financeiras adotadas para analisar a viabilidade da produção de cacau e banana no Perímetro Irrigado Tabuleiro de São Bernardo.
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The volatiles (VOCs) and semi-volatile organic compounds (SVOCs) responsible for aroma are mainly present in skin of grape varieties. Thus, the present investigation is directed towards the optimisation of a solvent free methodology based on headspace-solid-phase microextraction (HS-SPME) combined with gas chromatography–quadrupole mass spectrometry (GC–qMS) in order to establish the global volatile composition in pulp and skin of Bual and Bastardo Vitis vinifera L. varieties. A deep study on the extraction-influencing parameters was performed, and the best results, expressed as GC peak area, number of identified compounds and reproducibility, were obtained using 4 g of sample homogenised in 5 mL of ultra-pure Milli-Q water in a 20 mL glass vial with addition of 2 g of sodium chloride (NaCl). A divinylbenzene/carboxen/polydimethylsiloxane fibre was selected for extraction at 60 °C for 45 min under continuous stirring at 800 rpm. More than 100 VOCs and SVOCs, including 27 monoterpenoids, 27 sesquiterpenoids, 21 carbonyl compounds, 17 alcohols (from which 2 aromatics), 10 C13 norisoprenoids and 5 acids were identified. The results showed that, for both grape varieties, the levels and number of volatiles in skin were considerably higher than those observed in pulp. According to the data obtained by principal component analysis (PCA), the establishment of the global volatile signature of grape and the relationship between different part of grapes—pulp and skin, may be an useful tool to winemaker decision to define the vinification procedures that improves the organoleptic characteristics of the corresponding wines and consequently contributed to an economic valorization and consumer acceptance.
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In the first decades of 20th century the just instituted Brazilian Republic faced the challenge to modernize the country. Considering that the progress was associated with the exhaustion of the forest reserves and with climatic changes, two big issues were seen as fundamental: To Fight the Droughts and To Defend the Forests; headed by professionals who were dedicated to these ideals. This research starts from the premise that these were the main challenges enforced by nature to the Brazilian development; the general objective was delimited in the search to understand the meaning and the conception of the natural world by this group of professionals who faced the shock between modernizing the country and conserving its natural resources. Aiming to contribute with the construction of the Brazilian environmental history and to bring historical elements to the debate about the environment in the country, the author concentrates his attention to the analyses, the discussions and the actions that preceded the regulation on the use of natural resources and the implementation of the environmental legislation in Brazil, occurred in 1934. The investigation uses as methodological basis the theoretical directions of environmental history, using sources of data still little explored and valued. In such way, it is taken as starting point some published papers about this subject during the period between 1889 and 1934 in two technical magazines the Revista Brazil Ferro-Carril and the Revista do Club de Engenharia. National engineering played a basic role in this process while arguing, projecting and constructing the development. The formulated proposals, after being divulged, had fomented the interchange with other professionals and had favored the advance of ambient questions in Brazil, in the sense to preserve natural resources, to construct more harmonic relations between the society and the nature and to equate the development with the environment preservation
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This study aimed to describe the spatial and temporal patterns of variation in trophic state and its relation with the structure and dynamics of planktonic community of a large reservoir located in semi-arid tropical region of Northeast Brazil. The reservoir Armando Ribeiro Gonçalves is the biggest reservoir of the Rio Grande do Norte State and is responsible for about 53% of all surface water accumulated in the State. The samples of water and plankton were taken monthly in 10 points distributed throughout the longitudinal axis of the reservoir and over a full hydrological cycle. The samples were collected to determine concentrations of total phosphorus, total nitrogen, chlorophyll a and suspended solids (fixed and volatile) and for determining the composition and abundance of phytoplanktonic and zooplanktonic species. During the study period, the reservoir was characterized as eutrophic and there was no trend of increasing the trophic state of the reservoir in the period of drought. The concentrations of total phosphorus and suspended fixed solids decreased towards the dam while the N:P ratios increased in the same direction due to the reduction in the phosphorus concentrations and relative constancy in the nitrogen concentrations. The N:P ratios observed were indicative of greater limitation by phosphorus than by nitrogen. However, as concentrations of both nutrients were high and the water transparency was very low, with secchi depth usually lower than one meter, it seems likely that the planktonic primary production of the reservoir is more limited by the availability of light than the availability of nutrients. High nutrient concentrations coupled with low availability of light may explain the continuing dominance of filamentous cyanobacteria such as Cylindrospermopsis raciborskii in the plankton of the reservoir.These cyanobacteria are potentially toxic and pose a serious environmental problem because it compromises the water quality for public supply, recreation and fishing when present in high densities as in this study. The mesozooplankton of the reservoir was dominated by the calanoid Notodiaptomus cearensis and the cladoceran Diaphanosoma spinulosum. In general, the structure of zooplankton community seems to be particularly influenced by the spatial variation of cyanobacteria. The results of the regression analyses show that both the chlorophyll a concentrations and the cyanobacteria biovolume were more strongly correlated with the nitrogen than with phosphorus and that the water transparency was more strongly correlated with algal biomass than with other sources of turbidity. The maximum load of phosphorus to attain the maximum permissible concentration of total P in the reservoir was estimated in 63.2 tonnes P/ year. The current external P load to the reservoir is estimated in 324 tonnes P / year and must be severely reduced to improve the water quality for water supply and allow the implementation of aquaculture projects that could contribute to the socio-economic development of the region
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The aims of this study were: i) assessing the trophic state of the Mendubim reservoir (semi-arid, Rio Grande do Norte, Brazil; 05° 38 99,0 S 36°55 98,0 W) based on chlorophyll-a, total phosphorus and nitrogen concentrations and water transparency; ii) relating the patterns of temporal variation of zooplankton and phytoplankton to the trophic state of the reservoir and iii) investigating the carrying capacity of the reservoir for cage fish farming. The samplingwas done monthly from July 2006 to July 2007 in three stations at the reservoir: next to the dam (barrage), in the central region and in the mouth of the main tributary. The abiotic and biotic variables analyzed were: Secchi depth, volatiles and fixed suspended solids, chlorophyll-a, total phosphorus and nitrogen, TN:TP ratio and mesozooplankton and phytoplankton composition and biomass. The results showed that the reservoir can be considered as mesotrophic with mean concentrations of total nitrogen, phosphorus and chlorophyll-a equal to 1711, 1 μg.L-1, 30,8 μg.L-1 and 5,62 μg.L-1 respectively. The Cyanophyceae class was the most representative in terms of density, with the presence of potentially toxic species such as Microcystis aeruginosa, Planktothrix planctonica, Cylindrospermopsis raciborskii, Aphanizomenon sp. ,Aphanocapsa delicatissima and Pseudanabaena acicularis. Among the zooplankton, the genus Notodiaptomus presented the largest biomass values. Overall, our results show that the light limitation should explain the weak relationship between chlorophyll-a and total phosphorus and nitrogen concentrations. We concluded that the water of Mendubim reservoir is suitable for intensive fish cage aquaculture. Based on the carrying capacity calculations for this reservoir, we found that the maximum sustainable yield of tilapias in cages in the reservoir is 126 ton per year assuming a factor of food conversion of 1.5: 1.0 and a phosphorus content in the fish food of 1%
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The feeding habits and biological aspects of the reproductive cycle of two-spot astyanax, Astyanax cf. lacustris (Reinhardt, 1874) were investigated. Fish samples were captured on a monthly basis, using gillnets of 4 cm mesh size, from the Piató Lake, Assu, Rio Grande do Norte, during the period of September, 2006 to August, 2007. Physico-chemical parameters, such as, temperature, electrical conductivity and dissolved oxygen of the lake were registered. The monthly values of rainfall also were obtained. The 360 individuals captured, were measured, weighed, dissected, and stomach weight and the stage of gonadal maturity were registered. The stomach contents analyses were carried out based on volumetric method, points, frequency of occurrence and applying the Index of Relative Importance. The degrees of repletion of the stomachs were determined besides the Index of Repletion relating to feeding activity variations and frequency of ingestion with limnological parameters and rainfall. The food items identified were separated into distinct groups according to their origin. Sex ratio and Gonadosomatic Relation of females were verified to determine the spawning period and fecundity. The physico-chemical parameters presented the following annual mean values: temperature = 28.8ºC, electrical conductivity = 992.5 µS.cm-1; dissolved oxygen = 4.9 mg.L-1 during the study period. The annual mean of the rainfall was 63.5 mm. The results indicate that this species present an omnivorous feeding habit with a tendency towards insectivory, with an increase in feeding activity during the dry season. The aquatic oxygen to interfere very importance in the feeding activity than the others factors physico-chemicals of water and rainfall. There was a predominance of females, with a sex proportion of 1M:7F. The macroscopic characteristics of the ovaries and testicles revealed four stages of gonadal development: immature, maturing, mature and spent. A temporal variation was observed for the gonadal development of males and females. There was reproductive activity through out the year, with peaks in the months of February, April and June to correspond with the rain of precipitation of the region. The mean fecundity was 7.681 mature oocytes, varying from 4.476 to 12.036, with mean of 7.681. There was positive relation between fecundity and body mass. Condition Factor is not an efficient indicator of the reproductive period of this species. The species A. cf. lacustris is an opportunist and is well adapted to the conditions of the semi-arid Caatinga Biome
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Artificial lakes must differ from natural lakes in important structural and functional aspects that need to be understood so that these ecosystems can be properly managed. The aim of this work was to test the hypothesis that the artificial lakes (impoundments) in the semi-arid region of the Rio Grande do Norte State are more eutrophic and turbid and have different trophic structure when compared to the natural coastal lakes that occur in the humid eastern coast of the State. To test this hypothesis, 10 natural lakes and 8 artificial lakes with about 100 ha were sampled between September and November 2005 for the determination of some limnological variables and the abundance of the main fish species, which were grouped in three trophic guilds: facultative piscivores, facultative planktivores and omnivores. The results show that the artificial lakes had significantly higher concentrations of total nitrogen, total phosphorus, chlorophyll a , total and volatile suspended solids than the natural lakes. Results also show that the values of pH, total alkalinity, electric conductivity, turbidity as well as the coefficient of vertical attenuation of light were significantly higher in the artificial lakes than in the natural lakes. In the artificial lakes, the abundance of facultative planktivores was significantly higher, while the abundance of facultative piscivores significantly lower than in the natural lakes. There was no significant difference in the abundance of omnivorous fish between the two types of lakes. These results suggest that the increase in turbidity together with the other changes in the water quality of the artificial lakes, modifies the trophic structure of the fish communities reducing the importance of piscivores and the length of the food chains
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The Brazil is the third largest producer of cashew nuts in the world. Despite the social and economic importance of the cashew nut, its production is still carried out artisanally. One of the main problems encountered in the cashew production chain are the conditions under which the roasting of the nut occurs to obtain the kernel from the shell. In the present study was conducted a biomonitoring of the genotoxic and cytotoxicity effects associated with the elements from the cashew nut roasting in João Câmara - RN, semi-arid region of Brazil. To assess the genotoxic was used the bioassay of micronucleus (MN) in Tradescantia pallida. In addition, it was performed a comparative between the Tradescantia pallida and KU-20 and other biomarkers of DNA damage, such as the nucleoplasmic bridges (NBP) and nuclear fragments (NF) were quantified. The levels of particulate matter (PM1.0, PM2.5, PM10) and black carbon (BC) were also measured and the inorganic chemical composition of the PM2.5 collected was determined using X-ray fluorescence spectrometry analysis and the assessment of the cytotoxicity by MTT assay and exclusion method by trypan blue. . For this purpose, were chosen: the Amarelão community where the roasting occurs and the Santa Luzia farm an area without influence of this process. The mean value of PM2.5 (Jan 2124.2 μg/m3; May 1022.2 μg/m3; Sep 1291.9 μg/m3) and BC (Jan 363.6 μg/m3; May 70.0 μg/m3; Sep 69.4 μg/m3) as well as the concentration of the elements Al, Si, P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Se, Br and Pb obtained at Amarelão was significantly higher than at Santa Luzia farm. The genotoxicity tests with T. pallida indicated a significant increase in the number of MN, NBP and NF and it was found a negative correlation between the frequency of these biomarkers and the rainfall. The concentrations of 200 μg/mL and 400 μg/mL of PM2.5 were cytotoxic to MRC-5 cells. All together, the results indicated genotoxicity and citotoxicity for the community of Amarelão, and the high rates of PM2.5 considered a potential contributor to this effect, mainly by the high presence of transition metals, especially Fe, Ni, Cu, Cr and Zn, these elements have the potential to cause DNA damage. Other nuclear alterations, such as the NPBs and NFs may be used as effective biomarkers of DNA damage in tetrads of Tradescantia pallida. The results of this study enabled the identification of a serious occupational problem. Accordingly, preventative measures and better practices should be adopted to improve both the activity and the quality of life of the population. These measures are of fundamental importance for the sustainable development of this activity.
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Sisal is a renewable agricultural resource adapted to the hostile climatic and soil conditions particularly encountered in the semi-arid areas of the state of Rio Grande do Norte. Consequently, sisal has played a strategic role in the economy of the region, as one of few options of income available in the semi-arid. Find new options and adding value to products manufactured from sisal are goals that contribute not only to the scientific and technological development of the Northeastern region, but also to the increase of the family income for people that live in the semi-arid areas where sisal is grown. Lignocellulosic fibers are extracted from sisal and commonly used to produce both handcrafted and industrial goods including ropes, mats and carpets. Alternatively, addedvalue products can be made using sisal to produce alumina fibers (Al2O3) by biotemplating, which consists in the reproduction of the natural fiber-like structure of the starting material. The objective of this study was to evaluate the conditions necessary to convert sisal into alumina fibers by biotemplating. Alumina fibers were obtaining after pretreating sisal fibers and infiltrating them with a Al2Cl6 saturated solution, alumina sol from aluminum isopropoxide or aluminum gas. Heat-treating temperatures varied from 1200 ºC to 1650 °C. The resulting fibers were then characterized by X-ray diffraction and scanning electronic microscopy. Fibers obtained by liquid infiltration revealed conversion only of the surface of the fiber into α-Al2O3, which yielded limited resistance to handling. Gas infiltration resulted in stronger fibers with better reproduction of the inner structure of the original fiber. All converted fibers consisted of 100% α-Al2O3 suggesting a wide range of technological applications especially those that require thermal isolation
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The composition of termite assemblages was analyzed at three Caatinga sites of the Seridó Ecological Station, located in the municipality of Serra Negra do Norte, in the state of Rio Grande do Norte, Brazil. These sites have been subjected to selective logging, and cleared for pasture and farming. A standardized sampling protocol for termite assemblages (30h/person/site) was conducted between September 2007 and February 2009. At each site we measured environmental variables, such as soil granulometry, pH and organic matter, necromass stock, vegetation height, tree density, stem diameter at ankle height (DAH) and the largest and the smallest crown width. Ten species of termites, belonging to eight genera and three families, were found at the three experimental sites. Four feeding-groups were sampled: wood-feeders, soil-feeders, wood-soil interface feeders and leaf-feeders. The wood-feeders were dominant in number of species and number of encounters at all sites. In general, the sites were not significantly different in relation to the environmental variables measured. The same pattern was observed for termite assemblages, where no significant differences in species richness, relative abundance and taxonomic and functional composition were observed between the three sites. The agreement between the composition of assemblages and environmental variables reinforces the potential of termites as biological indicators of habitat quality
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Arthropods are abundant organisms possess great wealth and diversity representing about 82% of all known animal species. Contribute as a source of biomass and their abundance is an indicator of ecological change. The aim of this study was to evaluate the biomass and abundance found in the salt marsh environment throughout the year and relate them to the climatic factors (temperature, precipitation and relative humidity) that can influence the abundance and biomass of arthropods. The study was conducted at the Centro de Lançamento de Foguetes Barreira do Inferno, city of Parnamirim, Rio Grande do Norte, in the period February 2011 to January 2012, using pitfall traps, stationary window and beating tray. Among the 26 orders found, the most abundant were: Hymenoptera, Orthoptera, Araneae. Taxa Hymenoptera, Blattodea and Orthoptera showed higher biomass volume. Climatic factors did not influence the fall of Arthropods in the traps, however, the lowest abundance during the rainy season the action of raindrops, reduced the activity of these arthropods on vegetation, reducing its capture in traps (pitfall traps and stationary window ) and method of collection(entomological umbrella)
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Reproductive strategy of the hermaphrodite fish the marbled swamp eel, Synbranchus marmoratus (Bloch, 1795) (Osteichthyes: Synbranchidae) was investigated in the Marechal Dutra reservoir, Acari, Rio Grande do Norte, using fish samples captured monthly during the period of July 2010 to July 2011. The limnological parameters and rainfall were verified. The captured fish specimens were numbered, weighed, measured, dissected and their gonads and liver were removed, weighed and identified as to sex and developmental stages of gonads. The length-weight relationship was determined for grouped sex. The size of first gonadal maturation, gonadosomatic index (GSI), condition factor (K) and hepatosomatic index (HSI) were calculated. The development stages of the gonads were investigated using macroscopic and histological techniques, besides the fecundity and reproductive period. The macroscopic characteristics and the histological development of gonads confirmed the four different sexual types in the sampled population: primary males, females, intersex and secondary males. The secondary males were bigger and heavier than all the other types. This species showed a negative allometric growth with a higher increase in length than weight. The size at which 50% of the females began the process of gonadal maturation was 43.5 cm of total length, and for secondary males it was 58.5 cm. Condition factor showed two peaks in February and in April 2011. IGS indicated a reproductive period from July to September 2010 and was negatively correlated with the condition factor and rainfall. IGS showed a negative correlation when compared with the condition factor and the rainy season. HSI was highest in February ad lowest in December. The reproductive period of this species occurs between the end of the rainy season and the beginning of the dry season. S. marmoratus presents a seasonal reproductive strategy which optimizes its reproductive success under the semiarid climatic conditions
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The occurrence of human cancer in the municipality of Lucrécia (RN, Brazil) has shown high frequencies (INCA, 2007). Tests of micronucleus (MN) and nuclear abnormalities (NA) were performed to assess the genotoxic potential of water from the Lucrécia dam, which is located in a semi-arid region under the influence of crop irrigation and irregular rainfall. Water samples were collected in this source for analyzing the concentration of cyanobacteria, metals and radioactivity. Erythrocytes of Nile tilapia (Oreochromis niloticus) were collected in dam and cells of human oral mucosa in the urban area of this municipality for the bioassays of MN and NA. In fish were also analyzed concentrations of metals in samples of liver and gills. The genotoxicity tests with biological samples of fish and humans have shown significant increases in the frequencies of MN and NA (p ≤ 0.05) and are indicative of increased DNA damage in relation to the control groups. In conclusion, the results obtained from water samples and biological municipality of Lucrécia indicates that the presence of chemical and microbiological pollutants, and increase of genotoxic in human of this municipality. We suggest the implementation of advanced water treatment, to prevent further degradation of the aquatic environment and decrease in the life quality. This research of environmental quality assessment was performed in order to contemplate a multi and interdisciplinary character of this water resource and that can induce genotoxic damage in the organisms in this study region