In this work, we investigate the Brazilian low-latitude ionospheric response to two corotating interaction regions (CIRs) and high-speed streams (HSSs) events during the solar minimum of solar cycle ...23, in 2008. The studied intervals are enclosed in the whole heliospheric interval, studied by other authors, for distinct longitudinal sectors. CIRs/HSSs are structures commonly observed during the descending and low solar activity, and they are related to the occurrence of coronal holes. These events cause weak-to-moderate recurrent geomagnetic storms characterized by negative excursions of the interplanetary magnetic field, IMF_Bz, as well as long-duration auroral activity, considered as a favorable scenario for continuous prompt penetration interplanetary electric field (PPEF). In this study, we used the vertical total electron content (VTEC) calculated from GPS receivers database from the Brazilian Continuous Monitoring Network managed by the Brazilian Institute of Geography and Statistics. Moreover, we analyzed the F-layer peak height, hmF2 and the critical plasma frequency, foF2, taken from a Digisonde installed at the southern crest of the equatorial ionization anomaly, in Cachoeira Paulista, CP. It was observed that during the CIRs/HSSs-driven geomagnetic disturbances VTEC increased more than 120% over the quiet times averaged values, which is comparable to intense geomagnetic storms. On the other hand, VTEC decreases were also observed during the recovery phase of the storm. Spectral analysis using gapped wavelet technique (GWT) revealed periodicities of 7, 9, 13.5 days, which are sub-harmonics of the solar rotation period, ~ 27 days. These periods in VTEC are closely associated with those observed in solar and geomagnetic indices such as Vsw, IMF_Bz and AE during CIRs/HSSs intervals. We discuss PPEF associated to IMF_Bz reconnection processes and the auroral activity as the most probable causes for the VTEC variations. These results can be of interest for studies related to space weather monitoring, modeling and forecasting, especially during low solar activity.
We investigate the electronic and structural properties of two activated carbon models interacting with a Ni2+ ion via theoretical calculations. Interaction distances, charge transfer, adsorption ...energy, electrostatic potential maps, and density of states are applied in this work to support which activated carbon model is more favorable for nickel removal from the environment. We show that the existence of a defect in the activated carbon molecular structure causes a considerable change in the properties of the system, including its nickel ion removal feature via the adsorption process.
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•The adsorption mechanism between Ni2+ and activated carbon is investigated by the DFT method.•Calculations show Ni2+ adsorption is a spontaneous, endothermic reaction.•Defect taking an essential point regarding the reactivity of the activated carbon system.
The tomato leafminer, Tuta absoluta, now a major pest of tomato crops worldwide, is primarily controlled using chemical insecticides. Recently, high levels of resistance to the insecticide spinosad ...have been described in T. absoluta populations in Brazil. Selection of a resistant field-collected strain led to very high levels of resistance to spinosad and cross-resistance to spinetoram, but not to other insecticides that target the nicotinic acetylcholine receptor (nAChR). In this study the mechanisms underlying resistance to spinosad were investigated using toxicological, biochemical and molecular approaches. Inhibition of metabolic enzymes using synergists and biochemical assessment of detoxification enzyme activity provided little evidence of metabolic resistance in the selected strain. Cloning and sequencing of the nAChR alpha 6 subunit from T. absoluta, the spinosad target-site, from susceptible and spinosad-resistant strains were done to investigate the role of a target-site mechanism in resistance. A single nucleotide change was identified in exon 9 of the alpha 6 subunit of the resistant strain, resulting in the replacement of the glycine (G) residue at position 275 observed in susceptible T. absoluta strains with a glutamic acid (E). A high-throughput DNA-based diagnostic assay was developed and used to assess the prevalence of the G275E mutation in 17 field populations collected from different geographical regions of Brazil. The resistant allele was found at low frequency, and in the heterozygous form, in seven of these populations but at much higher frequency and in the homozygous form in a population collected in the Iraquara municipality. The frequency of the mutation was significantly correlated with the mortality of these populations in discriminating dose bioassays. In summary our results provide evidence that the G275E mutation is an important mechanism of resistance to spinosyns in T. absoluta, and may be used as a marker for resistance monitoring in field populations.
The development of biocompatible polymeric nanoparticles has become an important strategy for optimizing the therapeutic efficacy of many classical drugs, as it may expand their activities, reduce ...their toxicity, increase their bioactivity and improve biodistribution. In this study, nanoparticles of Amphotericin B entrapped within poly (lactic-co-glycolic) acid and incorporated with dimercaptosuccinic acid (NANO-D-AMB) as a target molecule were evaluated for their physic-chemical characteristics, pharmacokinetics, biocompatibility and antifungal activity. We found high plasma concentrations of Amphotericin B upon treatment with NANO-D-AMB and a high uptake of nanoparticles in the lungs, liver and spleen. NANO-D-AMB exhibited antifungal efficacy against Paracoccidioides brasiliensis and induced much lower cytotoxicity levels compared to D-AMB formulation in vivo and in vitro. Together, these results confirm that NANO-D-AMB improves Amphotericin B delivery and suggest this delivery system as a potential alternative to the use of Amphotericin B sodium deoxycholate.
Biodistribution scintigraphic images of nanoparticles labeled with the radioisotope technetium 99: amphotericin loaded nanoparticles (99mTc-NANO-D-AMB) or free DMSA after 1 and 8 h of intravenously injection. Display omitted
•Amphotericin B is a widely used antifungal, but toxicity limits its use.•NANO-D-AMB was proposed to optimize efficacy and reduce toxicity of this drug.•NANO-D-AMB had similar antifungal efficacy than AMBISOME®.•NANO-D-AMB had lower toxicity compared to D-AMB in vivo and in vitro.•NANO-D-AMB improves drug delivery and might be a potential alternative to D-AMB.
Loss and fragmentation of native vegetation negatively affect crop pollinators and productivity of several crop species. The yellow passion fruit is an excellent model to investigate this issue, ...because its main pollinators are sensitive to deforestation. Seasonality also influences fruit set of crop species that are pollinated by bees. Climate determines plant flowering patterns and consequently affects pollinator activity. Little is known on effects of pollinators on crop quality in general, and particularly of many tropical fruits that have multiple fruiting seasons throughout the year, such as passion fruit. Our hypothesis is that the distance to the native vegetation and climate seasonality affect the pollination and fruit production of cultivated, hermaphrodite, self-incompatible, protandrous species that depend on large-sized bees to set fruit. We observed flowers of the yellow passion fruit in eight areas at different distances (600-4,000 m) from a dry seasonal forest (Caatinga). We compared the frequency of the main floral visitor (pollinators and robbers) visits and fruit set among areas at the beginning and end of the dry and rainy seasons. Xylocopa species were pollinators, and Apis mellifera, Trigona spinipes and a hummingbird were robbers. Xylocopa visits diminished with increasing distance to native remnants, converse to what was observed for the robbers at the beginning of the dry season. Fruit set was higher at the beginning of the dry season. The distance to the forest affected quality of fruits in terms of length, diameter and skin thickness, which all decreased with increase in remnant distance. Our results show that insect pollination is higher in the dry season, increasing profitability and reducing labour costs for the producer. Considering the influence of distance to native vegetation on pollination, robbery and fruit quality, our study reinforces the necessity for conservation of native vegetation remnants.
Endometrial pathogenic E. coli (EnPEC) isolates are involved in endometrial infections in animals and humans. Besides the high aggressiveness of the endometrial infections, the EnPEC virulence ...profile and pathogenesis are still little known. In this study, we have sequenced and analyzed an EnPEC strain from canine pyometra (E. coli_LBV005/17), following a molecular characterization of the virulence profile and phylogenetic evolution of an EnPEC collection from canines and felines (45 strains). Most of the strains belonged to phylo-group B2, and display a high virulence profile. In particular we highlight the classification of the E. coli_LBV005/17 as sequence type 131 (ST131), in addition to other five strains, as observed by gyrB phylogenetic analysis. Also, the phylogenetic position of EnPEC strains from pyometra in companion animals suggests that their origins are from both extraintestinal and commensal E. coli strains. Accordingly to Principal Coordinates Analysis (PCoA) and phylogenetic analysis we can propose that EnPEC strains have neither the same genetic profile, nor a unique common ancestral. In summary, the present work characterize an EnPEC genome from bitch pyometra and the genetic profile of 45 EnPEC strains from companion animals pyometra, being the commonest virulence pattern: fimA, papC, hlyA, hlyE, cnf1, entB, iroN, irp1, bssS, bssR, and hmsP. These data improving the background knowledge of this E. coli pathotype related to pyometra in companion animals and may support new methods to prevent the disease evolution.
•An EnPEC isolated from canine pyometra had its genome described and classified as ST131.•EnPEC strains isolated from canines and felines have a high virulent potential.•Most of EnPEC strains isolates in companion animals pyometra cases were classified as B2 phylo-group.•The phylogenetic evolution of companion animals EnPECs seems to be from ancestral both intestinal and extraintestinal E. coli.
Abstract Introduction Bacterial taxa in the forefront of caries biofilms are candidate pathogens for irreversible pulpitis and are possibly the first ones to invade the pulp and initiate endodontic ...infection. This study examined the microbiota of the most advanced layers of dentinal caries in teeth with irreversible pulpitis. Methods DNA extracted from samples taken from deep dentinal caries associated with pulp exposures was analyzed for the presence and relative levels of 33 oral bacterial taxa by using reverse-capture checkerboard hybridization assay. Quantification of total bacteria, streptococci, and lactobacilli was also performed by using real-time quantitative polymerase chain reaction. Associations between the target bacterial taxa and clinical signs/symptoms were also evaluated. Results The most frequently detected taxa in the checkerboard assay were Atopobium genomospecies C1 (53%), Pseudoramibacter alactolyticus (37%), Streptococcus species (33%), Streptococcus mutans (33%), Parvimonas micra (13%), Fusobacterium nucleatum (13%), and Veillonella species (13%). Streptococcus species, Dialister invisus , and P. micra were significantly associated with throbbing pain, S. mutans with pain to percussion, and Lactobacillus with continuous pain ( P < .05). Quantitative polymerase chain reaction revealed a mean total bacterial load of 1 × 108 (range, 2.05 × 105 to 4.5 × 108 ) cell equivalents per milligram (wet weight) of dentin. Streptococci and lactobacilli were very prevalent but comprised only 0.09% and 2% of the whole bacterial population, respectively. Conclusions Several bacterial taxa were found in advanced caries lesions in teeth with exposed pulps, and some of them were significantly associated with symptoms. A role for these taxa in the etiology of irreversible pulpitis is suspected.
The purpose of this study was to determine the accuracy and intrarater reliability of a palpatory protocol based on a combination of 3 palpatory methods to identify both the C7 spinous process (C7 ...SP) and the factors that affect the errors and inaccuracy of palpation.
Twenty-five women between the ages of 18 and 60 years were submitted to a palpation protocol of the C7 SP, and a radiopaque marker was fixed on the skin at the possible location of the vertebrae. A radiograph and a photograph of the cervical spine were obtained in the same posture by a first rater. A second rater performed the same palpation protocol and took a second photograph. The accuracy and measurement error of the palpation protocol of C7 SP were assessed through radiographic images. The inter-rater reliability was estimated by the interclass correlation coefficient and assessed using photographs of each rater. The Pearson's correlation coefficients (r), the Fisher exact test, and the χ2 test were used to identify the factors associated with the error and inaccuracy of palpation.
Accuracy of the C7 palpation was 76% with excellent reliability (interclass correlation coefficient = 0.99). There was a moderate correlation between weight and the measurement of palpation error (r = –0.6; P = .003). One hundred percent of inaccuracy palpation was related to the increased soft-tissue thickness (P = .005) in the cervical region.
The palpation protocol described in this study was accurate and presented excellent reliability in identifying the C7 SP. Increased weight and dorsocervical fat pad were associated to error and palpation inaccuracy, respectively.
ABSTRACT The increase in distributed generation (DG) interferes with the energy distribution system, which may present low voltages due to voltage drops and high voltages due to the insertion of ...distributed generation, resulting from renewable energy sources in rural areas. These voltage levels must be controlled to comply with the limits imposed by the distribution rules and procedures (PRODIST). This study aims to evaluate the voltage rise caused by DG, simulating three DG insertion scenarios, as well as simulate strategies to correct these voltage levels, such as the limitation of the active power supply, the reactive supply by the consumer and the utility, and the installation of on-load tap changers. The simulations were performed using the MATLAB® program, more specifically the PSAT toolbox. Correction techniques were simulated using the active power supply limitation method, the reactive power supply method by consumers, and the voltage regulator process once the voltage rise effect was identified. The first two proved to be ineffective in this case, while the last one meets the voltage levels required by the National Electric Energy Agency.
ABSTRACT Sesame ( Sesamum indicum L.) oilseed needs to be studied in relation to the production of biodiesel and its application as an alternative to the soybean biodiesel used in Brazil. The aim of ...this study was to evaluate biodiesel blends (B0, B5, B10, B20, B40, B80, and B100) of sesame in the performance and emissions of engines. A few studies of sesame biodiesel in engines were found in the literature imparts novelty to the current study. The fuels were tested in a 5-kVA generator engine at loads ranging from 1000 to 6000 W. The results of the analysis showed that the increase in the sesame biodiesel blend caused a reduction in the specific fuel consumption (SFC), carbon monoxide (CO) emissions, and an increase in nitrogen oxide (NOx) emissions. The SFC of sesame biodiesel (B100) was 11% higher than that of diesel (B0). CO emissions increased 39% for diesel (B0) compared to sesame biodiesel (B100). However, B20 showed lower SFC than diesel and lower gas emissions than B80 and B100 blends. Therefore, sesame biodiesel, especially up to B20, is a viable alternative for the partial replacement of conventional diesel. Sesame biodiesel should be considered as a promising candidate for alternative fuels.
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