Discrete Self-Similarity in Interfacial Hydrodynamics and the Formation of Iterated Structures

The formation of iterated structures, such as satellite and sub-satellite drops, filaments and bubbles, is a common feature in interfacial hydrodynamics. Here we undertake a computational and theoretical study of their origin in the case of thin films of viscous fluids that are destabilized by long-range molecular or other forces. We demonstrate that iterated structures appear as a consequence of discrete self-similarity, where certain patterns repeat themselves, subject to rescaling, periodically in a logarithmic time scale. The result is an infinite sequence of ridges and filaments with similarity properties. The character of these discretely self-similar solutions as the result of a Hopf bifurcation from ordinarily self-similar solutions is also described.Comment: LaTeX, 5 pages, replaced with minor changes, accepted for publication in Physical Review Letter

Monitoramento em três hortos florestais de eucalipto no Estado de São Paulo da praga exótica percevejo bronzeado Thaumastocoris Peregrinus (Hemiptera: Thaumastocoridae).

O objetivo desse trabalho é apresentar os resultados obtidos pelo método de monitoramento do percevejo bronzeado Thaumastocoris peregrinus, (Hemiptera: Thaumastocoridae) em hortos florestais de Eucalyptus urograndis em três regiões do estado de São Paulo, quanto às respectivas flutuações populacionais (SÁ) deste inseto sob essas condições ambientais. De origem Australiana, este percevejo teve seu nome comum dado em função da coloração ?bronzeada? associada ao sintoma da injúria que causa nas folhas do eucalipto. Na Austrália vem sendo controlado com a utilização de inseticida sistêmico (Imidacloprido) injetado no tronco das árvores; e eficiente no controle (BUBOLA) desta praga em áreas urbanas. No Brasil desde maio/2008, quando detectado no município de São Francisco de Assis-RS e em junho/2008 em Jaguariúna-SP, vem se espalhando rapidamente para outras regiões já se fazendo presente em nove estados. O Laboratório de Quarentena ?Costa Lima? (LQC) da Embrapa Meio Ambiente vem estudando alternativas para o controle biológico desse inseto exótico realizada em talhões de E. urograndis utilizando-se de cartões armadilhas adesivas amarelas instaladas em hortos florestais localizados nas regiões de Campinas (Mogi-Guaçu), Rio Claro (Brotas) e Ribeirão Preto (Luiz Antônio), no estado de São Paulo, sendo substituído mensalmente e enviados, posteriormente, ao LQC para triagem, e contagem dos insetos capturados. Sendo assim os resultados do monitoramento indicaram a variação de adultos por horto florestal, mostrando sua maior concentração para que possam ser determinadas formas de controle à praga

Model of irrigation management on green spaces

The presented Model of Irrigation Management was designed for application on green spaces and leisure areas. The Model recognizes water as a production key-factor and optimizes its use on the irrigation of green spaces, giving particular attention to the temporal and spatial variation of input variables. Variables entered in the Model included existing or future target plant species, phenological phases, type of soil (i.e. location and physical characteristics), topography and climate factors. Model construction was similar to the methods outlined in FAO Report 56, namely: the method of Penman-Monteith for the calculation of reference evapotranspiration, the use of dual cultural coefficients to obtain cultural evapotranspirationand the opportunity of irrigation according to the hydric balance. The Model integrates the programming of algorithms implemented in Visual Basic 6, VB6 and a Geographic Information System (GIS). The Model provides the irrigation parameters in real-time scale, the timings for irrigation, depth per irrigation, the period of irrigation, time between two irrigation episodes, and for the sprinkle irrigation, the mean application rate and the degree of pulverization. The Model is used in association with an automatic weather station and irrigation system

Detection of extended-spectrum β-lactamase and carbapenemase activity in Gram-negative bacilli using liquid chromatography - tandem mass spectrometry

PURPOSE: Several mass spectrometry-based methods for antimicrobial sensitivity testing have been described in recent years. They offer an alternative to commercially available testing systems which were considered to have disadvantages in terms of cost- and time-efficiency. The aim of this study was to develop a LC-MS/MS-based antibiotic hydrolysis assay for evaluating antimicrobial resistance of Gram-negative bacteria. METHODS: Four species of Gram-negative bacilli (Klebsiella pneumoniae, Escherichia coli, Providencia stuartii and Acinetobacter baumannii) were tested against six antibiotics from three different classes: ampicillin, meropenem, imipenem, ceftazidime, ceftriaxone and cefepime. Bacterial suspensions from each species were incubated with a mixture of the six antibiotics. Any remaining antibiotic following incubation were measured using LC-MS/MS. The results were interpreted using measurements obtained for an E. coli strain sensitive to all antibiotics and expressed as percentage of hydrolyzed antibiotic. These were subsequently compared to commercially-available system for the bacteria identification and susceptibility testing. RESULTS: Overall, LC-MS/MS assay and commercial antimicrobial susceptibility platform results showed good agreement in terms of an organism being resistant/sensitive to an antibiotic. The time required to complete the LC-MS/MS-based hydrolysis test was under 5 h, significantly shorter that commercially available susceptibility testing platforms. CONCLUSION: By using a sensitive strain for results interpretation and simultaneous use of multiple antibiotics, the proposed protocol offers improved robustness and multiplexing over previously described methods for antibiotic sensitivity testing. Nevertheless, further research is needed before routine assimilation of the method, especially for strains with intermediate resistance

Classification of cancer cell lines using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and statistical analysis

Over the past decade, matrix-assisted laser desorption/ionization time‑of‑flight mass spectrometry (MALDI‑TOF MS) has been established as a valuable platform for microbial identification, and it is also frequently applied in biology and clinical studies to identify new markers expressed in pathological conditions. The aim of the present study was to assess the potential of using this approach for the classification of cancer cell lines as a quantifiable method for the proteomic profiling of cellular organelles. Intact protein extracts isolated from different tumor cell lines (human and murine) were analyzed using MALDI‑TOF MS and the obtained mass lists were processed using principle component analysis (PCA) within Bruker Biotyper® software. Furthermore, reference spectra were created for each cell line and were used for classification. Based on the intact protein profiles, we were able to differentiate and classify six cancer cell lines: two murine melanoma (B16‑F0 and B164A5), one human melanoma (A375), two human breast carcinoma (MCF7 and MDA‑MB‑231) and one human liver carcinoma (HepG2). The cell lines were classified according to cancer type and the species they originated from, as well as by their metastatic potential, offering the possibility to differentiate non‑invasive from invasive cells. The obtained results pave the way for developing a broad‑based strategy for the identification and classification of cancer cell

The Cytotoxic Effects of Betulin-Conjugated Gold Nanoparticles as Stable Formulations in Normal and Melanoma Cells

Gold nanoparticles are currently investigated as theranostics tools in cancer therapy due to their proper biocompatibility and increased efficacy related to the ease to customize the surface properties and to conjugate other molecules. Betulin, [lup-20(29)-ene-3β, 28-diol], is a pentacyclic triterpene that has raised scientific interest due to its antiproliferative effect on several cancer types. Herein we described the synthesis of surface modified betulin-conjugated gold nanoparticles using a slightly modified Turkevich method. Transmission electron microscopy (TEM) imaging, dynamic light scattering (DLS), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) were used for the characterization of obtained gold nanoparticles. Cytotoxic activity and apoptosis assessment were carried out using the MTT and Annexin V/PI apoptosis assays. The results showed that betulin coated gold nanoparticles presented a dose-dependent cytotoxic effect and induced apoptosis in all tested cell lines

The Infertility-Related Stress Scale: Validation of a Brazilian–Portuguese Version and Measurement Invariance Across Brazil and Italy

Infertility constitutes an essential source of stress in the individual and couple's life. The Infertility-Related Stress Scale (IRSS) is of clinical interest for exploring infertility-related stress affecting the intrapersonal and interpersonal domains of infertile individuals' lives. In the present study, the IRSS was translated into Brazilian-Portuguese, and its factor structure, reliability, and relations to sociodemographic and infertility-related characteristics and depression were examined. A sample of 553 Brazilian infertile individuals (54.2% female, mean aged 36 ± 6 years) completed the Brazilian-Portuguese IRSS (IRSS-BP), and a subsample of 222 participants also completed the BDI-II. A sample of 526 Italian infertile individuals (54.2% female, mean aged 38 ± 6 years) was used to test for the IRSS measurement invariance across Brazil and Italy. Results of exploratory structural equation modeling (ESEM) indicated that a bifactor solution best represented the structure underlying the IRSS-BP. Both the general and the two specific intrapersonal and interpersonal IRSS-BP factors showed satisfactory levels of composite reliability. The bifactor ESEM solution replicated well across countries. As evidence of relations to other variables, female gender, a longer duration of infertility, and higher depression were associated with higher scores in global and domain-specific infertility-related stress. The findings offer initial evidence of validity and reliability of the IRSS-BP, which could be used by fertility clinic staff to rapidly identify patients who need support to deal with the stressful impact of infertility in the intrapersonal and interpersonal life domains, as recommended by international guidelines for routine psychosocial care in infertility settings