Microservice architectures (MSAs) can increase the performance of distributed systems and enable better resource allocation by sharing underlying resources among multiple microservices (MSs). One of ...the main advantages of MSAs is the ability to leverage the elasticity provided by an infrastructure so that only the most demanding services are scaled, which can contribute to efficient allocation of processing resources. A major problem in allocating resources to microservices is determining a set of auto-scaling parameters that will result in all microservices meeting specific service level agreements (SLAs). Since the space of feasible configurations can be vast, manually determining a combination of parameter values that will result in all SLAs being met is complex and time consuming. In addition, the performance overhead caused by running microservices concurrently and the overhead caused by the VM instantiation process must also be evaluated. Another problem is that microservices can suffer performance degradation due to resource contention, which depends on how microservices are distributed across servers. To address the aforementioned issues, this paper proposes the modeling of these infrastructures and their auto-scaling mechanisms in a private cloud using stochastic Petri nets (SPNs), the non-dominated sorting genetic algorithm II (NSGA-II), one of the most popular evolutionary algorithms for multiobjective optimization (MOO), and random forest regression (RFR), an ensemble-learning-based method, to identify critical trade-offs between performance and resource consumption considering all deployed MSs. The SPN-based model is capable of representing both instantiation of elastic VMs and a pool of instantiated elastic VMs where only containers are started. The analytical framework enables service providers (SPs) to estimate performance metrics considering configurations that satisfy all performance constraints, use of elastic VMs, discard rate, discard probability, throughput, response time, and corresponding
cumulative distribution functions
(CDFs). These metrics are critical because they make it possible to estimate the time required to process each request, the number of requests processed in a time interval, the number of requests rejected, and the utilization of resources. The framework was validated with 95% confidence interval (CI) using a real-world testbed. Two case studies were used to investigate its feasibility by evaluating its application in a real scenario. We noticed a significant improvement in performance when using a pool of elastic VMs, where throughput improved by 21.5% and the number of discarded requests decreased by 70%. The application of the framework can help in finding optimized solutions that support both infrastructure planning and online performance prediction, and enable trade-off analyses considering different scenarios and constraints.
A high performance liquid chromatography (HPLC) method was developed for the simultaneous isolation, on a semi-preparative scale, of chavibetol and methyleugenol from the crude essential oil of
...leaves. The purity of the isolated compounds and their quantifications were developed using GC/FID. Chavibetol was isolated with high purity (98.7%) and mass recovery (94.6%). The mass recovery (86.4%) and purity (85.3%) of methyleugenol were lower than those of chavibetol. Both compounds were identified on the basis of spectral analysis. The results suggest that the method can provide chavibetol with high purity, mass recovery, and productivity from crude essential, which will be used in bioassays against stored insect pests.
Mobile cloud computing (MCC) is a technique for increasing the performance of mobile apps and reducing their energy consumption through code and data offloading. Developers may build MCC applications ...on a public cloud. The public cloud may offer economies of scale, but there are some considerations to take into account. Cloud providers charge their customers by data traffic, and wrong offloading decisions may lead to financial losses. This paper proposes an approach for estimating applications’ performance, data traffic generated by tasks offloading and its related costs on a public cloud. This work proposes both a stochastic Petri net (SPN)-based formal framework to represent MCC applications in a method-call level and a cost model to predict data traffic volume. Our approach enables designers to plan and tune MCC architectures based on three performance metrics:
mean time to execute
,
cumulative distribution function
, and
throughput
. Our SPN-based framework represents the use and sharing of the bandwidth available for offloading operations as well as the effect of bandwidth variation on the evaluated metrics. It allows a more accurate evaluation by developers about the performance of their applications taking into account specific network requirements, users, and offloading strategies. Two case studies were performed. Our approach has proven to be feasible, and it highlights the most appropriate strategies, supporting developers at design time by providing statistical information about applications’ behavior and costs estimations.
Currently, the fruit processing industry generates a high volume of waste in fruits that have not reached a quality standard for consumption or by-products generated throughout the production ...process. To reduce this waste, mitigating measures, such as reuse in food formulations, have been proposed. In this work the custard apple bagasse flour (Annona squamosa L.) (CAB) was produced and incorporated into cookie formulations in different proportions (5 to 50%) evaluating its acceptability. The CAB flour was characterized by physicochemical analysis, proximate composition, mineral analysis, determination of the phenolic content, and antioxidant capacity. The results of the physicochemical and proximate characterizations show that the processed flour presents values and specifications suitable for food formulations. The mineral composition of the CAB flour responds to more than 20% of the daily intake of nutrients, highlighting the Cu, Fe, Mn, Zn, Ca, and Mg. The composition of phenolic compounds for CAB flour and cookies formulations presented values ranging from 200 to 658 mg GAE/100 g, similar to flour and formulations prepared of residues tropical fruit, while D P P H • inhibition showed a variation of 9.68–10.75%. Cookies made from the CAB flour showed high acceptability making the flour promising in the nutritional incorporation in food formulations.
O presente estudo teve como objetivo avaliar diferentes substratos na germinação de Melocactus oreas (Britton & Rose). Os substratos testados foram: T1: terra preta, T2: terra preta e areia (1:1), ...T3: terra preta, areia e esterco (2:1:1), e T4: terra preta, areia e casca de arroz carbonizada (2:1:1), os substratos foram acondicionados em bandejas. O teste de germinação foi conduzido em casa de vegetação. O delineamento foi inteiramente casualizado com quatro repetições de 25 sementes por tratamento. Foram avaliadas a porcentagem de germinação e a velocidade de germinação. Conclui-se que o melhor substrato para germinação de M. oreas foi o composto formado por terra preta e areia (1:1), com 93% de germinação
Let F be a field of characteristic 0 and let UTm(F) be the algebra of upper triangular matrices of order m with entries from F. In this paper we give a description of the Y-proper graded cocharacters ...of UTm(F) equipped with any elementary G-grading, where G is a finite group.
O presente trabalho analisa a Pesquisa em Ensino de Química e sua relação com a prática docente. As pesquisas foram localizadas nas Atas do Encontro Nacional de Pesquisa em Educação em Ciências ...(ENPEC) no período de 1999 a 2013, identificando de cada um destes trabalhos um conjunto de descritores, por meio da metodologia da pesquisa do Estado da Arte. Constatou-se que as pesquisas englobam, principalmente, focos temáticos envolvendo Recursos Didáticos, Conteúdo-Método e Formação de professores. De posse destes indicativos teóricos, durante três meses foram acompanhadas as aulas de quatro professores que ministram a disciplina de Química no Ensino Médio, verificando a sua prática docente, observando como se estabelece a relação professor e aluno no contexto da sala de aula, os conteúdos ministrados, as estratégias didáticas utilizadas, os recursos didáticos adotados e as formas de avaliação da aprendizagem. Evidencia-se o distanciamento entre o que se pesquisa na área e o que se faz efetivamente no contexto escolar.
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•Annonaceae species were screened in order to detected sources of insecticidal compounds against Spodoptera frugiperda.•Ethanolic extract from Annona mucosa seeds (ESAM) was the most ...promising treatment, causing acute, and chronic effects on S. frugiperda.•The acetogenin bis-tetrahydrofuran rolliniastatin-1 was identified as the primary compound from the most active fractions of ESAM.•Rolliniastatin-1 caused both strong mortality and pronounced growth inhibition to S. frugiperda.
Annonaceae species are interesting sources of structurally diverse compounds with insecticidal properties. Therefore, a screening assay was conducted on ethanolic extracts prepared from the leaves, branches, and seeds of different Annonaceae species (Annona cacans Warming, Annona montana Macfadyen, Annona mucosa Jacquin, Annona reticulata Linnaeus, Annona sylvatica A. St.-Hil., and Duguetia lanceolata A. St.-Hil.) to detect promising sources of compounds with action against Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae). The ethanolic extract from A. mucosa seeds (ESAM) was the most active treatment, causing significant acute toxicity (LC50=842.9mgkg−1) and pronounced larval growth inhibition (EC50=580.4mgkg−1) after 7 days of exposure to an ESAM-treated diet. Furthermore, ethanolic extracts (at 1000mgkg−1) from seeds of A. cacans, A. montana, A. mucosa, and A. sylvatica; leaves and branches of A. reticulata; and D. lanceolata leaves only caused sublethal effects, reducing the S. frugiperda larval weight. Nevertheless, ESAM (at LC90) showed an efficacy similar to that of two commercial insecticides of natural azadirachtin+3-tigloylazadirachtol (Azamax® 1.2 EC) and synthetic chlorantraniliprole (Premio® 20 SC) origins, which were tested at the registered concentration for S. frugiperda control. Thus, using different chromatographic techniques, bioguided fractionations were conducted and led to the isolation of acetogenin bis-tetrahydrofuran rolliniastatin-1, which was identified as the primary compound from the most active fractions of ESAM. This compound, which caused both strong mortality and pronounced growth inhibition to S. frugiperda, may be a useful component for the integrated management of this important pest species.
Fish species diversity in headwaters streams of Paraguay and Paraná Basins Súarez, Yzel Rondon(UEMS Centro Integrado de Análise e Monitoramento Ambiental Laboratório de Ecologia); Valério, Sabrina Bigatão(UEMS Centro Integrado de Análise e Monitoramento Ambiental Laboratório de Ecologia); Tondado, Karina Keyla(UFMT) ...
Brazilian Archives of Biology and Technology,
11/2007, Letnik:
50, Številka:
6
Journal Article
Recenzirano
Odprti dostop
The influence of spatial, temporal and environmental factors on fish species diversity in headwater streams in Paraguay and Paraná basins, Brazil was examined. A total of 4,605 individuals were ...sampled, distributed in 60 species. The sampled streams in Paraná basin presented a larger total species richness (42) than Paraguay streams (40). However the estimated richness was larger in Paraguay basin (53) than Paraná streams (50). The streams of Paraná basin had a greater mean species richness and evenness, while more individuals per sample were found in the Paraguay basin. Difference between the sub-basins were found in the Paraguay basin, while for the basin of Paraná, richness and evenness vary significantly between the sub-basins, but the number of individuals varied seasonally. The most important environmental factors to species diversity and abundance were altitude, water temperature, stream width and stream depth for both the basins.
Examinamos a influência da variação espacial, temporal e das variáveis ambientais sobre as comunidades de peixes em riachos de cabeceira das bacias dos rios Paraguai e Paraná (Brasil). 4.605 indivíduos foram amostrados, distribuídos em 60 espécies. Os riachos da bacia do rio Paraná apresentaram maior riqueza total de espécies (42) que os riachos da bacia do rio Paraguai (40), no entanto, a riqueza estimada foi maior na bacia do rio Paraguai (53) que nos da bacia do rio Paraná (50). Os riachos da bacia do rio Paraná apresentaram maiores valores médios de riqueza e equitabilidade, contudo, maiores valores médios de número de indivíduos foram obtidos na bacia do rio Paraguai. Encontramos diferenças significativas entre as sub-bacias do rio Paraguai assim como do rio Paraná para a riqueza de espécies e equitabilidade, contudo, nesta última o número de indivíduos variou apenas sazonalmente. As variáveis ambientais mais importantes na determinação da diversidade e abundancia das espécies foram altitude, temperatura da água, largura e profundidade dos riachos para as duas bacias.
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