1,721,036 research outputs found
Valoração ambiental de efluentes de laticínios com cultivo da microalga Phormidium sp.
Get PDFDue to the high demand for energy and fertilizers, there is a need for new technologies to replace finite sources with alternative sources for the production of these compounds. In view of this, microalgae biomasses appear as raw material for the production of biofuels and biofertilizers, and among them, the microalgae Phormidium sp. has this ability to multiply in a medium with the addition of effluents. Thus, the use of alternative media, such as whey, for the cultivation of microalgae reduces the costs of its production and provides a source of organic nutrients for its growth, in addition to removing the contaminating agents of this by product from the manufacture of cheese. The general objective of the study was to seek the valuation of agro-industrial effluents through the cultivation of the microalgae Phormidium sp. in a culture medium with the addition of whey. The concentrations of reducing sugar consumption over time were also quantified, in addition to evaluating the final characteristics of the COD, N and P supernatant. After the cultivation period, a characterization of the produced biomass was carried out in terms of protein and carbohydrate contents. To evaluate the ability of the microalgae Phormidium sp. be cultivated in a culture medium with the addition of whey, tests were carried out with the addition of the residue in a concentration of 1% (v/v) related to the volume of the useful part of the reactor. The time intervals between the additions were varied, from 3, 5 and 7 days, and the cultivation time was 30 days. At the end of the experiment, it was concluded that the microalgae survived the addition of whey, becoming an alternative for valuing the effluent that was previously discarded, because through the concentration readings, a greater microalgal growth can be seen in the additions of whey. In the readings of reducing sugar concentration there was a use of lactose by the microalgae, and in the readings of DQO, N and P also showed that the microalgae Phromidium sp. treated the effluent, as the initial accumulated concentration is greater than the final one. Also, its biomass presented a potential alternative for the production of biofertilizers, causing the dairy industries to use their wastewater in the production of biofertilizers, generating income and reducing expenses with the final disposal of the sludge generated in their treatment.Devido a alta demanda energética e de fertilizantes, surge a necessidade de novas tecnologias para a substituição de fontes finitas por fontes alternativas de produção destes compostos. Em vista disto, as biomassas microalgais surgem como matéria prima para a produção de biocombustíveis e biofertilizantes, e dentre elas, a microalga Phormidium sp. tem esta capacidade de se multiplicar em meio com adição de efluentes. Assim, a utilização de meios alternativos, como soro de leite, para o cultivo de microalgas diminui os custos de sua produção e disponibiliza uma fonte de nutrientes orgânicas para seu crescimento, além de remover os agentes contaminantes deste subproduto proveniente da fabricação de queijos. O objetivo geral do estudo foi buscar a valoração de efluentes agroindustriais através do cultivo da microalga Phormidium sp. em meio de cultivo com adição de soro de leite. Também foram quantificadas as concentrações de consumo de açúcar redutor ao longo do tempo, além de avaliar as características finais do sobrenadante de DQO, N e P. Após o período de cultivo foi realizada uma caracterização da biomassa produzida quanto aos teores de proteínas e carboidratos. Para avaliar a capacidade da microalga Phormidium sp. ser cultivada em meio de cultivo com adição de soro de leite, foram realizados ensaios com a adição do resíduo em concentração de 1% (v/v) relacionados com o volume do útil do reator. Foram variados os intervalos de tempos entre as adições, de 3, 5 e 7 dias, e o tempo de cultivo foi de 30 dias. Ao final do experimento conclui-se que a microalga sobreviveu a adição de soro, se tornando uma alternativa de valoração do efluente que antes era descartado, pois através das leituras de concentração pode-se perceber um crescimento microalgal maior nas adições de soro de leite. Nas leituras de concentração de açúcar redutor houve uma utilização da lactose por parte da microalga, e nas leituras de DQO, N e P também mostraram que a microalga Phromidium sp. tratou o efluente, pois a concentração acumulada inicial é maior que a final. Também, sua biomassa apresentou potencial alternativa para a produção de biofertilizantes fazendo com que as indústrias de laticínios utilizem suas águas residuárias na produção de biofertilizantes, gerando renda e diminuindo os gastos com disposição final de lodo gerado no tratamento das mesmas
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Otimização da produção biotecnológica de lipases e correlação com a produção de biossurfactantes
Get PDFAs lipases e os biossurfactantes são compostos produzidos por microrganismos através de
fermentações em estado sólido (FES) ou sumberso (FSm), os quais são aplicáveis nas
indústrias alimentícia e farmacêutica, na bioenergia e na biorremediação, entre outras. O
objetivo geral deste trabalho foi otimizar a produção de lipases através de fermentação em
estado sólido e fermentação submersa. Os fungos foram selecionados quanto à habilidade
de produção de lipases através de FES e FSm e aqueles que apresentaram as maiores
atividades lipolíticas foram utilizados na seleção de variáveis significativas e na otimização
da produção de lipases nos dois modos de cultivo. Foram empregadas técnicas seqüenciais
de planejamento experimental, incluindo planejamentos fracionários, completos e a
metodologia de superfície de resposta para a otimização da produção de lipases. As
variáveis estudadas na FES foram o pH, o tipo de farelo como fonte de carbono, a fonte de
nitrogênio, o indutor, a concentração da fonte de nitrogênio, a concentração do indutor e a
cepa do fungo. Na FSm, além das variáveis estudadas na FES, estudaram-se as variáveis
concentração inicial de inóculo e agitação. As enzimas produzidas foram caracterizadas
quanto à temperatura e pH ótimos e quanto à estabilidade a temperatura e pH. Nas
condições otimizadas de produção de lipases, foi avaliada a correlação entre a produção de
lipases e bioemulsificantes. Inicialmente foram isolados 28 fungos. Os fungos Aspergillus O-
4 e Aspergillus E-6 foram selecionados como bons produtores de lipases no processo de
fermentação em estado sólido e os fungos Penicillium E-3, Trichoderma E-19 e Aspergillus
O-8 como bons produtores de lipases através da fermentação submersa. As condições
otimizadas para a produção de lipases através de fermentação em estado sólido foram
obtidas utilizando-se o fungo Aspergillus O-4, farelo de soja, 2% de nitrato de sódio, 2% de
azeite de oliva e pHs inferiores a 5, obtendo-se atividades lipolíticas máximas de 57 U. As
condições otimizadas para a produção de lipases na fermentação submersa foram obtidas
utilizando-se o fungo Aspergillus O-8, farelo de trigo, 4,5% de extrato de levedura, 2% de
óleo de soja e pH 7,15. A máxima atividade obtida durante a etapa de otimização foi 6 U. As
lipases obtidas por FES apresentaram atividades máximas a 35ºC e pH 6,0, enquanto que
as obtidas por FSm apresentaram ótimos a 37ºC e pH 7,2. A estabilidade térmica das
lipases produzidas via FSm foi superior a das lipases obtidas via FES, com atividades
residuais de 72% e 26,8% após 1h de exposição a 90ºC e 60ºC, respectivamente. As
lipases obtidas via FES foram mais estáveis em pH´s alcalinos, com atividades residuais
superiores a 60% após 24 h de exposição, enquanto as lipases produzidas via FSm foram
mais estáveis em pH´s ácidos, com 80% de atividade residual na faixa de pH entre 3,5 e 6,5.
Na fermentação submersa a correlação entre a produção de lipases e a atividade emulsificante óleo em água (O/A) e água em óleo (A/O) dos extratos foi 95,4% e 86,8%,
respectivamente, obtendo-se atividades emulsificantes máximas O/A e A/O de 2,95 UE e
42,7 UE. Embora a maior produção de lipases tenha sido obtida na fermentação em estado
sólido, não houve produção concomitante de biossurfactantes. Os extratos da fermentação
submersa apresentaram redução da tensão superficial de 50 mN m
-1
para 28 mN m
-1
e
atividade antimicrobiana frente ao microrganismo S. aureus ATCC 25923, com potenciais
antimicrobianos de 36 a 43% nos três primeiros dias de fermentação. A fermentação
submersa foi a técnica que apresentou os melhores resultados de otimização da produção
de lipases, bem como de produção simultânea de biossurfactantes.Lipases and biosurfactantes are compounds produced by microrganisms by solid state (SSF)
and submerged fermentations (SmF), being applied in food and pharmaceutical industries, in
bioenergy and bioremediation, between others. The aim of this thesis was to optimize the
production of lipases through solid state and submerged fermentations. The filamentous
fungi were selected by the ability of production of lipases in solid-state and submerged
fermentations and those that presented the highest lipolitic activities were used in the
screening of significant variables and optimization of the lipases production in the both
culture modes. The screening of variables and the optimization of lipase production were
accomplished using sequential techniques of experimental design, including fractionary and
complete designs and the response surface methodology. In solid state fermentation, the
variables pH, bran, nitrogen source, inductor, concentration of the nitrogen source and
inductor, and fungi were studied. In submerged fermentation beyond the variables studied in
SSF, it were studied the initial inoculum concentration and agitation. The enzymes produced
in the optimized conditions were characterized about its optimal temperature and pH and
about its stability in front of temperature and pH. In the optimized conditions of lipase
production, the correlation between lipases and bioemulsifiers production was verified. A
total of 28 fungi were isolated, being selected as good producers of lipases in solid state
fermentation the fungi Aspergillus O-4 and Aspergillus E-6, and as good producers of lipases
in submerged fermentation the strains Penicillium E-3, Trichoderma E-19 and Aspergillus O-
8. In solid state fermentation, optimized conditions of lipase production were obtained using
the fungi Aspergillus O-4, soy bran, 2% of sodium nitrate, 2% of olive oil and pHs varying of
3.5 to 4.5, being obtained maximal lipolitic activities of 57 U. The optimized conditions in
submerged bioprocess were obtained using the fungi Aspergillus (O-8), wheat bran, 4.5% of
yeast extract, 2% of soy oil and pH 7.15, being the maximal activities of 6 U. The optimal
activities of lipases produced in solid-state bioprocess were obtained in pH 6.0 and
temperature of 35°C and for the lipases produced in submerged fermentation at 37ºC and pH
7.2. Lipases produced by SmF were more stable than those produced by FES, with residual
activities of 72% and 26.8% after one hour of exposition at 90ºC and 60ºC, respectively.
Lipases obtained by FES presented higher stability in alcaline pH´s, with residual activities of
60% after 24 h of exposition, while lipases obtained in SmF were more stable in acid pH´s,
with 80% of residual activities in pH´s between 3.5 and 6.5. Lipases obtained in submerged
bioprocess presented maximum activities at 37ºC and pH 7.2, freezing stability at -20ºC
during 90 days, 80% of stability in pH of 3.5 to 6.5 and 50% of stability in pH of 7 to 10. With
respect of temperature stability, the lipases maintained 72% of residual activity intemperatures of 70 to 90ºC, being these good characteristics to industrial applications. In the
submerged bioprocess the correlation of lipase production and the oil/water and water/oil
emulsifier activity of the extracts were 95.4 and 86.8%, respectively, obtaining maximal
emulsifier activities oil/water and water/oil of 2.95 UE and 42.7 UE. In the solid-state
bioprocess, besides the best productivities of lipase production were obtained, no production
of biosurfactants was observed. The extracts of submerged fermentation presented reduction
of superficial tension of 50 to 28 mN m
-1
and antimicrobial activity against the S. aureus
ATCC 25923, with antimicrobial potentials of 36 to 43% until the third days of bioprocess.
The submerged bioprocess presented the best results in the optimization of lipases
production, as well as in the simultaneous production of biosurfactants. Lipases and
biosurfactants produced can be applied in food and pharmaceutical industries or in cases of
bioremediation
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Potencial de atenua??o natural de diesel (B8) e biodiesel (B100) em latossolo vermelho sem hist?rico de contamina??o
Get PDFDiesel oil, mainly composed of hydrocarbons, is currently the most consumed
petroleum derivative in Brazil. Biodiesel is added to the diesel sold in national territory,
according to current legislation. Biodiesel has emerged as an alternative fuel,
obtained from renewable sources, composed of fatty acid alkyl esters, less polluting
and more biodegradable. Soil microorganisms act in important processes, such as
the degradation and mineralization of a great diversity of organic compounds. Soil
contamination by fuels, which could occur in various forms during the production
chain, might inhibit part of the microbiota due to the toxicity of its components, but
also increase autochthonous populations capable of degrading such compounds.
The objective of this work was to evaluate, during 90 days, the biodegradation of
diesel (B8) and biodiesel (B100), applied in two concentrations (5 and 10%, m m-1) to
microcosms composed by a red latosol with no history of fuel contamination.
Contaminated soils showed higher respiration than uncontaminated soil. Particularly,
soils with diesel had a respiration up to 5.2 times higher than the control soil. Soils
with diesel presented greater hydrolysis of fluorescein diacetate and dehydrogenase
activity than the soils contaminated with biodiesel, but inferior than the control soil.
The soils contaminated with diesel presented respiration up to 5.2 times higher than
the control soil and presented greater activities of fluorescein diacetate hydrolysis
and dehydrogenase than the soils contaminated with biodiesel, but inferior to the
control soil when related to the enzymatic activities. Soils contaminated with diesel
had a higher number of microorganisms than the soils with biodiesel and control soil.
The microbial biomass carbon presented similar behavior to the enzymatic activities.
At the end of the 90 days, it was higher in the control soil, followed by the soil with
diesel and lower in the soil with biodiesel. The metabolic quotient indicated greater
stress of the microbiota in the soils contaminated with biodiesel in comparison to soils
with diesel and control soil. Phytotoxicity of soils contaminated with diesel, verified
through seed germination, was apparently reduced by more than 80% after 90 days
of soil incubation in relation to the initial toxicity. Biodiesel contamination resulted in
the highest phytotoxicity during the incubation. At the end of the incubation, there
was a reduction of 70% (diesel 5%) and 50% (diesel 10%) in the mass of the fuel
extracted from the soil; in biodiesel treatments, mass reductions were 61% (biodiesel
5%) and 48% (biodiesel 10%). At the end of the microcosm incubations, reductions in
retention peaks as well as in the areas of fuel components were observed through
gas chromatography analysis, suggesting biodegradation. After the 90 days of
incubation of the contaminated soils, 34 bacteria were isolated (24 from diesel
microcosms and 10 from biodiesel microcosms), of which 30 showed the capacity to
degrade fuels (diesel or biodiesel). Among these, 18 produced biosurfactants; for 10
isolates the production was mostly extracellular and for six isolates the biosurfactants
remained cell-associated. In addition to the production of biosurfactants, some of the
isolates, especially those isolated from soil with diesel, presented cellular
hydrophobicity values above 40%. In summary, it was verified that the soil used, even
without a history of contamination, displayed an autochthonous microbiota with the
capacity to degrade fuels under natural attenuation conditionsO ?leo diesel, composto basicamente por hidrocarbonetos, ? atualmente o derivado
de petr?leo mais consumido no Brasil. Biodiesel ? acrescido ao diesel
comercializado em territ?rio nacional, seguindo a legisla??o vigente. O biodiesel
surgiu como um combust?vel alternativo, de fontes renov?veis, composto por ?steres
alqu?licos de ?cidos graxos, menos poluentes e mais biodegrad?veis. Os
microrganismos do solo atuam em processos importantes como na degrada??o e
mineraliza??o de uma grande diversidade de compostos org?nicos. A contamina??o
do solo por combust?veis, que pode ocorrer de diversas formas durante a cadeia
produtiva, inibindo parte da microbiota pela toxicidade de seus componentes, mas
tamb?m incrementar popula??es aut?ctones capazes de degradar tais compostos. O
objetivo deste trabalho foi avaliar, durante 90 dias, a biodegrada??o de diesel (B8) e
biodiesel (B100), aplicados em duas concentra??es (5 e 10%, m m-1), em
microcosmos constitu?dos de latossolo vermelho sem hist?rico de contamina??o por
combust?veis. Os solos contaminados apresentaram respira??o superior ? do solo
n?o contaminado. Os solos contaminados com diesel apresentaram respira??o at?
5,2 vezes maior do que o solo controle e apresentaram maiores atividades de
hidr?lise do diacetato de fluoresce?na e da desidrogenase do que os solos
contaminados com biodiesel, por?m inferiores ao solo controle quando relacionado
aas atividades enzim?ticas. Solos contaminados com diesel apresentaram maior
n?mero de microrganismos do que os solos com biodiesel e solo controle. O
carbono da biomassa microbiana apresentou comportamento similar ?s atividades
enzim?ticas, sendo que, ao final dos 90 dias, foi maior no solo controle, seguido pelo
solo com diesel e inferior no solo com biodiesel. O quociente metab?lico indicou
maior estresse da microbiota nos solos contaminados com biodiesel em rela??o aos
solos com diesel e solo controle. A fitotoxicidade dos solos contaminados com diesel,
verificada atrav?s da germina??o de sementes, foi aparentemente reduzida em mais
de 80% ap?s 90 dias de incuba??o do solo em rela??o ? toxicidade inicial. A
contamina??o com biodiesel resultou na fitotoxicidade mais elevada no decorrer da
incuba??o. Ao final da incuba??o, houve redu??o de 70% (diesel 5%) e 50% (diesel
10%) na massa dos combust?veis extra?do do solo; nos tratamentos com biodiesel,
as redu??es de massa foram de 61% (biodiesel 5%) e 48% (biodiesel 10%). Ao final
do per?odo de incuba??o dos microcosmos tamb?m foram observadas, atrav?s de
cromatografia gasosa, redu??es nos picos de reten??o, bem como nas ?reas de
componentes dos combust?veis, sugerindo a biodegrada??o. Ap?s os 90 dias de
incuba??o dos solos contaminados foram isoladas 34 bact?rias (24 dos
microcosmos com diesel e 10 dos com biodiesel), das quais 30 apresentaram
capacidade de degradar combust?veis (diesel ou biodiesel). Dentre estas, 18
produziram biossurfactantes, sendo que para 10 isolados a produ??o foi
majoritariamente extracelular e para seis isolados os biossurfactantes
permaneceram associados ?s c?lulas. Al?m da produ??o de biossurfactantes, alguns
dos isolados, principalmente aqueles isolados de solo com diesel, apresentaram
valores de hidrofobicidade celular acima de 40%. Em suma, foi verificado que o solo
utilizado, mesmo sem hist?rico de contamina??o, apresentou microbiota aut?ctone
com capacidade de degradar combust?veis em condi??es de atenua??o natural
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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