195 research outputs found
Experimentation with radio environment maps for resources optimisation in dense wireless scenarios
The rapidly increasing popularity of WiFi has created
unprecedent levels of congestion in the unlicensed frequency
bands, especially in densely populated urban areas. This results
mainly because of the uncoordinated operation and the unmanaged
interference between WiFi access points. Recently, Radio
Environment Maps (REM) have been suggested as a support for
coordination strategies that optimize the overall WiFi network
performance. Despite some theoretical work done in this area,
there are no clear experimental evidences of the benefit brought
by WiFi coordination. In this context, the main objective of this
experiment is to assess the benefit of a coordinated management
of radio resources in dense WiFi networks using REMs for
indoor scenarios. This experiment has used the w-iLab.t test
environment provided by iMINDS, a cognitive-radio testbed for
remote experimentation. It was shown that REMs are capable
of detecting the presence of interfering links on the network
(co-channel or adjacent channel interference), and a suitable
coordination strategy can use this information to reconfigure
Access Points (AP) channel assignment and reestablish the client
connection. The coordination strategy almost double the capacity
of a WiFi link under strong co–channel interference, from
6.8 Mbps to 11.8 Mbps, increasing the aggregate throughput
of the network from 58.7 Mbps to 71.5 Mbps. However, this
gain comes with the cost of a relatively high density network
of spectrum sensors (12 sensors for an area of 60 × 20 m),
increasing the cost of deployment.info:eu-repo/semantics/publishedVersio
Influence de la densité de vegetation et de l'effeuillage sur le microclimat, rendement, composition du baie et qualité du vin du cépage portugais Touriga Nacional
The objectives of this experiment were to evaluate the influence of shoot density and basal leaf removal on the
canopy microclimate characteristics and their influence on yield, fruit composition and wine quality of one of the
most important and noble Portuguese red vine varieties – Touriga Nacional.
The experiment was carried out in 2004 on a private enterprise (Dão Sul, Soc. Vitivinícola, SA) of Dão region,
centre of Portugal. The vineyard was grafted in 1991 on 1103 P rootstock. The training system is Royat bilateral
with vertical shoot positioning. Three different shoot densities were applied: D1 – 23 shoots/m row, D2 – 17
shoots/m row and D3 – 11 shoots/m row. At veraison was also introduced another factor: leaf removal (under
clusters).
During the growing season several parameters were measured (leaf area, leaf water potential, leaf gas-exchanges,
leaf layer number, canopy size, intercepted photosynthetically active radiation, fruit composition, yield and
vigour).
Basal leaf removal improved the canopy microclimate by a lower leaf layer number with positive effects on the
interception of radiation at fruit zone, inferior percentage of interior leaves and clusters. On shoot density, it was
verified that the D2 presented the best conditions of canopy microclimate.
Yield was positively influenced by shoot density increase by the augment of the cluster number, while cluster
weight was not affected. Leaf removal had not a significant effect on yield parameters.
The lower shoot density (D3) improved wine quality by greater colour intensity. Leaf removal improved
significantly the wines colour intensity
Mechanical pruning and soil organic amendments in vineyards of Syrah: effects on grape composition
Aim: The interaction of mechanized pruning systems and soil organic amendment can increase vine productivity.
However, since the increase in p
roductivity may affect grape composition, this study aimed to understand the effects of the interaction between these
two practices.
Methods and materials: Two field trials were implemented in Shiraz vineyards in two different wine regions.
Mechanical hedge pruning was compared with hand spur pruning and four different organic amendments were tested:
biochar, municipal solid waste compost, cattle manure and sewage sludge.
Results: Mechanical pruning reduced the total soluble solids (TSS) and pH of the grapes, but had no effects on the other
variables. Organic amendments also reduced TSS, especially sewage sludge, and tended to reduce total anthocyanins
and total phenols. The effect of the interaction between both factors on grape composition was never significant.
A negative relationship between yield and TSS was observed, while titratable acidity had no relationship with yield.
Total anthocyanins were also negatively related to yield. A positive relation between TSS and total anthocyanins was
also observed.
Conclusions: The results show that the combination of mechanical pruning and soil organic amendment is a powerful
tool for increasing productivity, but it has some effects on grape composition.
Significance and impact of study: The reduction in some fruit composition variables showed that, while mechanical
pruning does not significantly affect grape composition, the choice of type and amount of organic amendment will
depend on the destination of the grapesinfo:eu-repo/semantics/publishedVersio
Impact of combined training with different exercise intensities on inflammatory and lipid markers in type 2 diabetes : a secondary analysis from a 1-year randomized controlled trial
© The Author(s) 2020. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creat ivecommons .org/licen ses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creat iveco mmons .org/publi cdoma in/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.Background: Exercise is a well-accepted strategy to improve lipid and infammatory profle in individuals with type 2 diabetes (T2DM). However, the exercise intensity having the most benefts on lipids and infammatory markers in patients with T2DM remains unclear. We aimed to analyse the impact of a 1-year combined high-intensity interval training (HIIT) with resistance training (RT), and a moderate continuous training (MCT) with RT on infammatory and lipid profle in individuals with T2DM. Methods: Individuals with T2DM (n=80, aged 59 years) performed a 1-year randomized controlled trial and were randomized into three groups (control, n=27; HIIT with RT, n=25; MCT with RT, n=28). Exercise sessions were super‑ vised with a frequency of 3 days per week. Infammatory and lipid profles were measured at baseline and at 1-year follow-up. Changes in infammatory and lipid markers were assessed using generalized estimating equations. Results: After adjusting for sex, age and baseline moderate-to-vigorous physical activity (MVPA), we observed a time-by-group interaction for Interleukin-6 (IL-6) in both the MCT with RT (β=−0.70, p=0.034) and HIIT with RT (β=−0.62, p=0.049) groups, whereas, only the HIIT with RT group improved total cholesterol (β=−0.03, p=0.045) and LDL-C (β=−0.03, p=0.034), when compared to control. No efect was observed for C-reactive protein (CRP), cortisol, tumour necrosis factor-α (TNF-α), soluble form of the haptoglobin-hemoglobin receptor CD163 (sCD163), triglycerides and HDL-C in both groups (p>0.05). Conclusions: Favorable adaptations on IL-6 were observed in both the HIIT and MCT combined with RT groups fol‑ lowing a long-term 1-year exercise intervention in individuals with T2DM. However, only the HIIT with RT prevented further derangement of total cholesterol and LDL-C, when compared to the control group. Therefore, in order to encourage exercise participation and improve infammatory profle, either exercise protocols may be prescribed, however, HIIT with RT may have further benefts on the lipid profle.This work was supported by fellowships from the Portuguese Foundation for Science and Technology (JM grant: SFRH/BD/85742/2012; IRC grant: IRC: SFRH/BD/149394/2019). This work is also fnanced by a national grant through the FCT–Fundação para a Ciência e Tecnologia within the unit I&D 447 (UIDB/00447/2020).info:eu-repo/semantics/publishedVersio
Nova estimativa da prevalência da infecção pelo vírus "TT" (TTV) em populações de baixo e alto risco de São Paulo, Brasil
A prevalência da infecção pelo vírus "TT" (TTV) foi investigada pela técnica da Reação da Polimerase em Cadeia (PCR) em grupos considerados de baixo risco (doadores de sangue e crianças/adolescentes saudáveis) e de alto risco de exposição parenteral (hemofílicos); todos provenientes da cidade de São Paulo. Oligonucleotídeos empregados como primers, homólogos à região não traduzível (UTR) do genoma viral, mostraram-se muito mais universais, revelando frequências muito mais altas em ambos os grupos ( >; ou = 81%) do que os primers anteriormente utilizados, baseados na região genômica traduzível "N22" (doadores de sangue, 5,5%, e hemofílicos, 42,3%). O "PCR-UTR" também revelou um perfil interessante em crianças/adolescentes saudáveis: alta prevalência nos primeiros anos de vida e queda significativa em meninos adolescentes. O "PCR-N22", por sua vez, apresentou alta frequência em hemofílicos que receberam derivados de sangue fresco (58%) relativa àqueles que foram tratados com fatores de coagulação submetidos à inativação viral (9,4%) e doadores de sangue (5,5%).The prevalence of TT virus (TTV) infection was investigated by Polymerase Chain Reaction (PCR) in low- (blood donors and healthy children/adolescents) and high-risk (hemophiliacs) groups from São Paulo, Brazil. Primers based on the untranslated region (UTR) of the viral genome proved to be much more ubiquitous, leading to much higher frequencies for both groups ( >; or = 81%) than the earlier N22-PCR directed to the open reading frame 1 (blood donors, 5.5%, and hemophiliacs, 42.3%). The UTR-PCR also revealed an interesting profile for healthy children/adolescents: very high prevalence at the early years and significant decrease in male teenagers. The N22-PCR, in turn, demonstrated higher frequency in hemophiliacs treated with fresh blood products (58%), than in those treated with virus-inactivated clotting factors (9.4%) and blood donors (5.5%)
Effect of a freeze on some technological characteristics of several sugar cane varieties
Em 18 de julho de 1975, ocorreu geada no Estado de São Paulo; em Piracicaba, a temperatura atingiu -1ºC. Aproveitou-se a ocorrência da geada para investigar seus efeitos sobre características tecnológicas de algumas variedades. Foram tomadas amostras de dez colmos cada uma, a partir de doze dias após a geada, e depois, aproximadamente, a cada duas semanas. Analisaram-se brix % caldo, pol % caldo e, por inferência, produção de açúcar provável (em kg/t de cana). Dadas as condições do meio ambiente e das próprias plantas, pode-se dizer que estas não sofreram alterações dignas de nota nas sete amostras quinzenais efetuadas após a geada, nas características analisadas. Aplicando-se análise de regressão, verificou-se que os dados de brix % caldo ajustaram-se melhor às curvas de 2º grau. O teste F para regressão foi significativo em nove dos quinze casos estudados.A freeze occurred in the State of São Paulo, on July, 18th, 1975 with the temperature decreasing to -1ºC in Piracicaba. Advantage was taken of this occurrence to study the effect of freeze on the technological characteristics of some commercial sugar cane varieties. Ten stalk samples were taken for the experiment, beginning at twelve days after the freeze and thereafter every two weeks. Brix % juice, pol % juice and, by inference, theoretical sugar yield (kg/t of cane) were studied. Due to the environmental and plant conditions in the field, it could be concluded that the varieties did not show significant alterations caused by the freeze in none of the seven fortnight samples. Regression analysis showed that brix % juice data fitted 2nd degree curves better than the other data, with F test significant in nine out of fifteen cases
Utilização de extratos de Pleurotus ostreatus como antioxidante natural em biodiesel: Use of Pleurotus ostreatus extracts as a natural antioxidant in biodiesel
A incorporação do biodiesel na matriz energética brasileira é de extrema importância para reduzir a importação de óleo diesel e diminuir os impactos ambientais gerados pelos gases de efeito estufa. Atualmente no Brasil a adição de biodiesel no óleo diesel é de 10%. Devido à biodegradabilidade do biodiesel, antioxidantes sintéticos são adicionados para aumentar sua vida útil, porém, esses compostos são derivados do petróleo e possuem potencial toxicidade e caráter carcinogênico. O objetivo deste trabalho foi utilizar extratos do Pleurotus ostreatus (P.O) como antioxidantes para biodiesel. Foram utilizadas técnicas rigorosas como: teste de oxidação acelerada (Rancimat® 873) e delineamento experimental simplex centróide. Para uso do P.O foram executadas a extração aquosa ácida, orgânica neutra e orgânica básica para extrair os compostos com potencial antioxidante e transferir-los para o biodiesel. A metodologia de extração aquosa ácida do P.O apresentou rendimento de 31,9%. Quando o biodiesel foi purificado com a solução ácida do Pleurotus ostreatus 5 g/L, o período de indução do biodiesel foi de 9,28 h (aumento de 183%), apresentando conformidade com a norma EN 14214
Mechanical pruning and soil organic amending in two terroirs. Effects on wine chemical composition and sensory profile
The knowledge about the interaction between mechanical pruning and soil organic amending is still
scarce. This study aimed to examine the effects of the interaction between these two practices on wine quality. Syrah
grapes from two trial fields in Portugal subjected to two different pruning systems (mechanical pruning; hand spur
pruning) and five different organic amendment treatments (control, biochar, municipal solid waste compost, cattle
manure, and sewage sludge) were harvested and vinified for four years. Mechanical pruning significantly reduced
wine alcoholic strength, pH, and total anthocyanins. Mechanical pruning and organic amendments, tendentially
reduced wine total phenols and tannin power, known as an “estimation of the astringency potential of the wines”.
Tasters found low but significant differences in global appreciation with the pruning system. Sludge tended to reduce
wine global appreciation more than municipal solid waste compost and cattle manure, while biochar had no effect
on tasters’ preference when compared to the control. There was strong relation between yield and tasters’ preference
only above 6 kg/vine and 8 kg/vine depending on the terroir. Mechanical pruning tendentially has significant
effects on wine quality when yield raises above a certain level. Thus, with this pruning system, the choice of the
organic amendment and its amount must be done considering the destiny of the produced grapes. To the best of our
knowledge, effects of the interaction of mechanical pruning with soil organic amending on wine quality are a noveltyinfo:eu-repo/semantics/publishedVersio
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Modular coherent photonic-aided payload receiver for communications satellites
Ubiquitous satellite communications are in a leading position for bridging the digital divide. Fulfilling such a mission will require satellite services on par with fibre services, both in bandwidth and cost. Achieving such a performance requires a new generation of communications payloads powered by large-scale processors, enabling a dynamic allocation of hundreds of beams with a total capacity beyond 1 Tbit s−1. The fact that the scale of the processor is proportional to the wavelength of its signals has made photonics a key technology for its implementation. However, one last challenge hinders the introduction of photonics: while large-scale processors demand a modular implementation, coherency among signals must be preserved using simple methods. Here, we demonstrate a coherent photonic-aided receiver meeting such demands. This work shows that a modular and coherent photonic-aided payload is feasible, making way to an extensive introduction of photonics in next generation communications satellites
Protein hydrolysates from salmon heads and cape hake by-products: comparing enzymatic method with subcritical water extraction on bioactivity properties
Fish by-products can be converted into high-value-added products like fish protein hydrolysates (FPHs), which have high nutritional value and are rich in bioactive peptides with health benefits. This study aims to characterise FPHs derived from salmon heads (HPSs) and Cape hake trimmings (HPHs) using Alcalase for enzymatic hydrolysis and Subcritical Water Hydrolysis (SWH) as an alternative method. All hydrolysates demonstrated high protein content (70.4–88.7%), with the degree of hydrolysis (DH) ranging from 10.7 to 36.4%. The peptide profile of FPHs indicated the breakdown of proteins into small peptides. HPSs showed higher levels of glycine and proline, while HPHs had higher concentrations of glutamic acid, leucine, threonine, and phenylalanine. Similar elemental profiles were observed in both HPHs and HPSs, and the levels of Cd, Pb, and Hg were well below the legislated limits. Hydrolysates do not have a negative effect on cell metabolism and contribute to cell growth. HPSs and HPHs exhibited high 2,2′–azino-bis(3 ethylbenzthiazoline-6)-sulfonic acid (ABTS) radical scavenging activity, Cu2+ and Fe2+ chelating activities, and angiotensin-converting enzyme (ACE) inhibitory activity, with HPHs generally displaying higher activities. The α-amylase inhibition of both FPHs was relatively low. These results indicate that HPHs are a promising natural source of nutritional compounds and bioactive peptides, making them potential candidates for use as an ingredient in new food products or nutraceuticals. SWH at 250 °C is a viable alternative to enzymatic methods for producing FPHs from salmon heads with high antioxidant and chelating properties.info:eu-repo/semantics/publishedVersio
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