The presence of green areas in urbanized cities is crucial to reduce the negative impacts of urbanization. However, these areas can influence the signal quality of IoT devices that use wireless ...communication, such as LoRa technology. Vegetation attenuates electromagnetic waves, interfering with the data transmission between IoT devices, resulting in the need for signal propagation modeling, which considers the effect of vegetation on its propagation. In this context, this research was conducted at the Federal University of Pará, using measurements in a wooded environment composed of the Pau-Mulato species, typical of the Amazon. Two machine learning-based propagation models, GRNN and MLPNN, were developed to consider the effect of Amazonian trees on propagation, analyzing different factors, such as the transmitter's height relative to the trunk, the beginning of foliage, and the middle of the tree canopy, as well as the LoRa spreading factor (SF) 12, and the co-polarization of the transmitter and receiver antennas. The proposed models demonstrated higher accuracy, achieving values of root mean square error (RMSE) of 3.86 dB and standard deviation (SD) of 3.8614 dB, respectively, compared to existing empirical models like CI, FI, Early ITU-R, COST235, Weissberger, and FITU-R. The significance of this study lies in its potential to boost wireless communications in wooded environments. Furthermore, this research contributes to enhancing more efficient and robust LoRa networks for applications in agriculture, environmental monitoring, and smart urban infrastructure.
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Abstract Opinions regarding the treatment of multicystic ameloblastoma are divergent due to its benign nature and the high rate of recurrence if not adequately excised. The aim of the present study ...was to perform a systematic review of the literature for a qualitative and quantitative assessment of studies addressing primary multicystic ameloblastoma with regard to treatment and recurrence. Searches were conducted of the Ovid Medline and Embase databases for articles published up to January 2014. Based on predefined eligibility criteria, studies were selected in a two-stage screening process conducted by two independent reviewers. Quality assessment of the selected articles was performed using the modified criteria of the Agency for Healthcare Research and Quality. The meta-analysis was performed using Review Manager (RevMan) software. Statistical heterogeneity was investigated by performing a χ2 test at the 5% significance level ( P < 0.05) and determining I2 . The relative risk of recurrence was 3.15-fold greater (95% confidence interval 1.98–5.00) when conservative treatment was performed on primary multicystic ameloblastoma in comparison to radical treatment ( P < 0.00001 for treatment effect; I2 = 0% and P = 0.48 for heterogeneity). The findings justify the treatment of primary multicystic ameloblastoma with bone resection.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Grazing exclusion may lead to biodiversity loss and homogenization of naturally heterogeneous and species-rich grassland ecosystems, and these effects may cascade to higher trophic levels and ...ecosystem properties. Although grazing exclusion has been studied elsewhere, the consequences of alleviating the disturbance regime in grassland ecosystems remain unclear. In this paper, we present results of the first five years of an experiment in native grasslands of southern Brazil. Using a randomized block experimental design, we examined the effects of three grazing treatments on plant and arthropod communities: (i) deferred grazing (i.e., intermittent grazing), (ii) grazing exclusion and (iii) a control under traditional continuous grazing, which were applied to 70 x 70 m experimental plots, in six regionally distributed blocks. We evaluated plant community responses regarding taxonomic and functional diversity (life-forms) in separate spatial components: alpha (1 x 1 m subplots), beta, and gamma (70 x 70 m plots), as well as the cascading effects on arthropod high-taxa. By estimating effect sizes (treatments vs. control) by bootstrap resampling, both deferred grazing and grazing exclusion mostly increased vegetation height, plant biomass and standing dead biomass. The effect of grazing exclusion on plant taxonomic diversity was negative. Conversely, deferred grazing increased plant taxonomic diversity, but both treatments reduced plant functional diversity. Reduced grazing pressure in both treatments promoted the break of dominance by prostrate species, followed by fast homogenization of vegetation structure towards dominance of ligneous and erect species. These changes in the plant community led to increases in high-taxa richness and abundance of vegetation-dwelling arthropod groups under both treatments, but had no detectable effects on epigeic arthropods. Our results indicate that decision-making regarding the conservation of southern Brazil grasslands should include both intensive and alleviated levels of grazing management, but not complete grazing exclusion, to maximize conservation results when considering plant and arthropod communities.
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The combined use of a microbial additive and a chemical additive in sorghum (Sorghum bicolor (L.) Moench) silages would reduce fermentation losses, favoring aerobic stability by modulating a ...favorable microbiome to control those losses. The purpose of this study was to evaluate the action of Lactobacillus buchneri and sodium benzoate on the fermentative profile, bacterial taxonomic diversity and aerobic stability of sorghum silages at different fermentation times. A completely randomized experimental design was adopted in a 4 * 4 factorial scheme, in order to evaluate four additives in sorghum silage (Control treatment, L. buchneri, sodium benzoate and L. buchneri combined with sodium benzoate) and four opening times (30, 60, 90 and 120 d fermentation), in five replicates. Silages inoculated with sodium benzoate showed higher pH values (3.70) at 90 d of fermentation, not differing (P > 0.05) from control (CTR) silage and the other silages. The largest lactic acid bacteria populations were observed at 120 d of fermentation in the silages inoculated with L. buchneri (9.06) followed by the silages inoculated with sodium benzoate and with the combination L. buchneri + sodium benzoate (8.37 and 8.85 log CFU, respectively) at 90 d of fermentation. For gas losses, in which silage treated with sodium benzoate showed lower values, with an average of 0.72% DM. The silages presenting a high DMR standard, ranging from 94.6% to 98.0%, with the exception of the CTR silages. Silages treated with L. buchneri showed higher values (98%) for the occurrence of the genus Lactobacillus in both fermentation times. The combined action of L. buchneri and sodium benzoate kept the Lactobacillus population stable at 30 and 120 d of fermentation. The combination of L. buchneri and sodium benzoate improved the fermentative profile and chemical composition of sorghum silages, reducing losses and increasing aerobic stability after 120 d of fermentation. Key words: Chemical additive, heterofermentative inoculant, microbial population, 16S ribosomal rRNA, Sorghum bicolor.
Brazil's large land base is important for global food security but its high dependency on inorganic phosphorus (P) fertilizer for crop production (2.2 Tg rising up to 4.6 Tg in 2050) is not a ...sustainable use of a critical and price-volatile resource. A new strategic analysis of current and future P demand/supply concluded that the nation's secondary P resources which are produced annually (e.g. livestock manures, sugarcane processing residues) could potentially provide up to 20% of crop P demand by 2050 with further investment in P recovery technologies. However, the much larger legacy stores of secondary P in the soil (30 Tg in 2016 worth over $40 billion and rising to 105 Tg by 2050) could provide a more important buffer against future P scarcity or sudden P price fluctuations, and enable a transition to more sustainable P input strategies that could reduce current annual P surpluses by 65%. In the longer-term, farming systems in Brazil should be redesigned to operate profitably but more sustainably under lower soil P fertility thresholds.
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Virtual sensors provisioning is a central issue for sensors cloud middleware since it is responsible for selecting physical nodes, usually from Wireless Sensor Networks (WSN) of different owners, to ...handle user's queries or applications. Recent works perform provisioning by clustering sensor nodes based on the correlation measurements and then selecting as few nodes as possible to preserve WSN energy. However, such works consider only homogeneous nodes (same set of sensors). Therefore, those works are not entirely appropriate for sensor clouds, which in most cases comprises heterogeneous sensor nodes. In this paper, we propose ACxSIMv2, an approach to enhance the provisioning task by considering heterogeneous environments. Two main algorithms form ACxSIMv2. The first one, ACASIMv1, creates multi-dimensional clusters of sensor nodes, taking into account the measurements correlations instead of the physical distance between nodes like most works on literature. Then, the second algorithm, ACOSIMv2, based on an Ant Colony Optimization system, selects an optimal set of sensors nodes from to respond user's queries while attending all parameters and preserving the overall energy consumption. Results from initial experiments show that the approach reduces significantly the sensor cloud energy consumption compared to traditional works, providing a solution to be considered in sensor cloud scenarios.
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Bioactivities from marine algae of the genus Gracilaria de Almeida, Cynthia Layse F; Falcão, Heloina de S; Lima, Gedson R de M ...
International Journal of Molecular Sciences,
07/2011, Volume:
12, Issue:
7
Journal Article, Book Review
Peer reviewed
Open access
Seaweeds are an important source of bioactive metabolites for the pharmaceutical industry in drug development. Many of these compounds are used to treat diseases like cancer, acquired ...immune-deficiency syndrome (AIDS), inflammation, pain, arthritis, as well as viral, bacterial, and fungal infections. This paper offers a survey of the literature for Gracilaria algae extracts with biological activity, and identifies avenues for future research. Nineteen species of this genus that were tested for antibacterial, antiviral, antifungal, antihypertensive, cytotoxic, spermicidal, embriotoxic, and anti-inflammatory activities are cited from the 121 references consulted.
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Olive oil has beneficial effects on skin wound healing due to its anti‐inflammatory and antioxidant properties; however, the mechanism by which olive oil promotes wound healing is unclear. We ...evaluated the mechanisms involved in Nrf2 pathway activation by olive oil and its role in cell survival and migration in mouse dermal fibroblasts in a short‐term exposition. Our data demonstrated that olive oil and oleic acid promoted reactive oxygen species (ROS) production, while olive oil and hydroxytyrosol stimulated nuclear factor erythroid 2‐related factor 2 (Nrf2) activation. Olive oil‐mediated ROS production increased nuclear factor kappa B p65 expression, while olive oil‐stimulated reactive nitrogen species production augmented the levels of Nrf2. Olive oil augmented cell proliferation, cell migration, and AKT phosphorylation, but decreased apoptotic cell number and cleaved caspase‐3 levels. The effect of olive oil on cell migration and protein levels of AKT, BCL‐2, and Nrf2 were reversed by an Nrf2 inhibitor. In conclusion, the activation of the Nrf2 pathway by olive oil promotes the survival and migration of dermal fibroblasts that are essential for the resolution of skin wound healing.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
We show that the gravitational phase space for the near-horizon region of a bifurcate, axisymmetric Killing horizon in any dimension admits a 2D conformal symmetry algebra with central charges ...proportional to the area. This extends the construction of Haco et. al. J. High Energy Phys. 12 (2018) 098JHEPFG1029-847910.1007/JHEP12(2018)098 to generic Killing horizons appearing in solutions of Einstein's equations and motivates a holographic description in terms of a 2D conformal field theory. The Cardy entropy in such a field theory agrees with the Bekenstein-Hawking entropy of the horizon, suggesting a microscopic interpretation. A set of appendixes is included in the Supplemental Material that provides examples and further details of the calculations presented in the main text.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UL, UM
Regular black holes in f(G) gravity de S. Silva, Marcos V.; Rodrigues, Manuel E.
The European physical journal. C, Particles and fields,
08/2018, Volume:
78, Issue:
8
Journal Article
Peer reviewed
Open access
In this work, we study the possibility of generalizing solutions of regular black holes with an electric charge, constructed in general relativity, for the
f
(
G
) theory, where
G
is the Gauss–Bonnet ...invariant. This type of solution arises due to the coupling between gravitational theory and nonlinear electrodynamics. We construct the formalism in terms of a mass function and it results in different gravitational and electromagnetic theories for which mass function. The electric field of these solutions are always regular and the strong energy condition is violated in some region inside the event horizon. For some solutions, we get an analytical form for the
f
(
G
) function. Imposing the limit of some constant going to zero in the
f
(
G
) function we recovered the linear case, making the general relativity a particular case.
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