WO3-decorated ZnO nanostructures for light-activated applications

In the present work, a two-step vapor-phase route was implemented for the tailored design of ZnO\u2013WO3 nanoheterostructures supported on fluorine-doped tin oxide (FTO) substrates. Under optimized conditions, the sequential use of chemical vapor deposition (CVD) and radio frequency (RF)-sputtering for the deposition of zinc and tungsten oxides respectively, resulted in the growth of calyx-like ZnO nanostructures uniformly decorated by a conformal dispersion of low-sized WO3 nanoparticles. The target materials were characterized by means of a multi-technique approach, with particular regard to their structural, compositional, morphological and optical properties. Finally, their photocatalytic performances were preliminarily tested in the abatement of NOX gases (NO and NO2). Due to the unique porous morphology of the ZnO nanodeposit and the high density of ZnO\u2013WO3 heterojunctions, WO3-decorated ZnO revealed appealing De-NOX characteristics in terms of both degradation efficiency and selectivity. Such features, along with the photoinduced superhydrophilicity and self-cleaning properties of the present nanomaterials, candidate them as promising functional platforms for applications in smart windows and building materials for environmental remediation

Stability of additive-free water-in-oil emulsions

We calculate ion distributions near a planar oil-water interface within non-linear Poisson-Boltzmann theory, taking into account the Born self-energy of the ions in the two media. For unequal self-energies of cations and anions, a spontaneous charge separation is found such that the water and oil phase become oppositely charged, in slabs with a typical thickness of the Debye screening length in the two media. From the analytical solutions, the corresponding interfacial charge density and the contribution to the interfacial tension is derived, together with an estimate for the Yukawa-potential between two spherical water droplets in oil. The parameter regime is explored where the plasma coupling parameter exceeds the crystallization threshold, i.e. where the droplets are expected to form crystalline structures due to a strong Yukawa repulsion, as recently observed experimentally. Extensions of the theory that we discuss briefly include numerical calculations on spherical water droplets in oil, and analytical calculations of the linear PB-equation for a finite oil-water interfacial width.Comment: 9 pages, 4 figures, accepted by JPCM for proceedings of LMC

A study of fuzzy data bases: an application to a Peruvian case

This paper aims to show the various types of data that contain in an intrinsically way fuzzy or imperfect data that are presented in the real world. A form of implementation is described that allows extending the capabilities of a database by using layers levels, emphasizing in the concept of inheritance. What is described is illustrated by an example applied to the Peruvian reality, which is shown with a certain level of detail

MOWING AND HERBICIDE APPLICATION TO CONTROL Megathyrsus maximus: DAMAGE ON PRE-EXISTING VEGETATION IN A 20-YEAR REFORESTATION SITE

A necessidade de controlar gram\uedneas ex\uf3ticas em \ue1reas de restaura\ue7\ue3o ecol\uf3gica por longos prazos pode acarretar elevados custos econ\uf4micos, danos colaterais \ue0 regenera\ue7\ue3o e danos menos \uf3bvios ao ecossistema. Assim, dimensionar estes fatores negativos como parte do esfor\ue7o para avaliar a raz\ue3o custo/benef\uedcio das t\ue9cnicas de controle dessas esp\ue9cies, se faz necess\ue1rio. Este estudo objetivou avaliar os danos causados por duas t\ue9cnicas de controle de capim-coloni\ue3o (Megathyrsus maximus (Jacq.) B. K. Simon & S. W. L. Jacobs), sobre a regenera\ue7\ue3o preexistente (custos ambientais), em um reflorestamento de 20 anos, e estimar os custos econ\uf4micos do emprego dessas t\ue9cnicas. Trinta parcelas de 10 x 20 m foram distribu\ueddas em tr\ueas grupos: (CON) controle, (ROC) ro\ue7agem com ro\ue7adeiras costais e (HERB) ro\ue7agem seguida da aplica\ue7\ue3o de herbicida \ue0 base de glifosato. Foi feito o invent\ue1rio permanente de todos os indiv\uedduos arb\uf3reos e arbustivos, os quais foram acompanhados durante o per\uedodo de um ano. N\ue3o houve diferen\ue7a na mortalidade imposta pela ro\ue7agem inicial, tampouco na mortalidade imposta exclusivamente pela ro\ue7agem ou pelo herbicida no HERB. Ap\uf3s um ano, n\ue3o houve diferen\ue7as entre a mortalidade e a riqueza de esp\ue9cies dos tr\ueas grupos. Quando os tr\ueas grupos foram comparados entre si ap\uf3s um ano, para as plantas > 1 m, houve redu\ue7\ue3o da abund\ue2ncia no CON e redu\ue7\ue3o da riqueza no HERB; j\ue1 para as plantas < 1 m, houve redu\ue7\ue3o da abund\ue2ncia no ROC, e redu\ue7\ue3o da abund\ue2ncia e riqueza no HERB. Portanto, tais t\ue9cnicas parecem afetar mais fortemente as plantas < 1 m. O custo econ\uf4mico final do ROC foi 34,1% maior do que o custo do HERB, e mesmo que o custo para se realizar novas interven\ue7\uf5es diminua para ambos, h\ue1 aumento dos custos quando ocorre necessidade de interven\ue7\uf5es esparsas em \ue1reas pequenas. Ambas as t\ue9cnicas s\ue3o indicadas para controlar o capim-coloni\ue3o, sendo que o uso de herbicida \ue0 base de glifosato deve ser restrito \ue0s \ue1reas com baixa cobertura de dossel, por demandarem mais manuten\ue7\uf5es, e por ser a t\ue9cnica mais prejudicial \ue0 regenera\ue7\ue3o, j\ue1 que houve alta mortalidade de indiv\uedduos de pequeno porte (73%) em \ue1reas com densa infesta\ue7\ue3o da gram\uednea (100%).The need to control exotic grasses in areas of ecological restoration for long periods is followed by high economical costs of application, collateral damage on regeneration and other less obvious environmental harms. Thus, it is necessary estimate such drawbacks in order to evaluate the cost/benefit rate of the application of these techniques. This study aimed to assess the damage caused by two control techniques of Guinea-grass (Megathyrsus maximus (Jacq.) B. K Simon & S. W. L. Jacobs), on pre-existing regeneration (environmental costs) in a 20-year reforestation site and estimate the economic costs of employing such techniques. Thirty 10 x 20m plots were divided into three groups: (CON) control, (ROC) mowing (using gas-powered brush cutters) and (HERB) mowing followed by the application of a glyphosate-based herbicide. We did a permanent inventory of all tree and shrub individuals, who were followed over a period of one year. No differences were found in mortality imposed by the initial mowing, neither in the mortality imposed exclusively by mowing nor in the mortality imposed exclusively by herbicide in HERB. After one year, there were no differences between mortality and species richness of the three groups. However, when the three groups were compared with themselves after one year, for plants > 1 m, we found a reduction on abundance in CON and reduction in species richness in HERB; whereas for plants < 1 m, ROC showed a reduction in abundance and HERB showed reduced abundance and species richness. Therefore, both techniques seem to affect more plants < 1 m (i.e., regeneration). The final economic cost of ROC was 34.1% bigger than the cost of HERB, and in spite of a likely reduction in costs to perform new interventions, proportional costs increased for scattered interventions over small areas. Both techniques were efficient to control Guinea-grass, but the use of glyphosate-based herbicide should be restricted to areas with low canopy cover, more maintenance-demanding sites, once the technique is more damaging on regeneration, since there was high mortality (73%) of individuals < 1 m in areas with dense grass infestation (100%)

Virulence Gene Expression of Staphylococcus aureus in Human Skin

Staphylococcus aureus is the main cause of human skin and soft tissue infections. However, S. aureus pathogenicity within the skin is not fully characterized. Here, we implemented an S. aureus cutaneous infection model using human skin explants and performed a time-course infection to study the gene expression profile of a large panel of virulence-related factors of S. aureus USA300 LAC strain, by high-throughput RT-PCR. We pinpointed the genes that were differentially regulated by the bacteria in the skin tissues and identified 12 virulence factors that were upregulated at all time points assessed. Finally, using confocal microscopy, we show that the expression of alpha-hemolysin by S. aureus varies dependent on the skin niche and that the bacteria preferentially accumulates inside sweat glands and ducts. Taken together, our study gives insights about the pathogenic lifestyle of S. aureus within human skin tissues, which may contribute for the development of anti-S. aureus therapeutic strategies

Comparison of shape analysis methods for Guinardia citricarpa ascospore characterization

Among the diseases affecting the commercial citrus production, the citrus black spot (CBS) is considered to cause substantial losses. The analyses of particles in suspension in the orchards and collected into a disc have been applied as a preventive action trying to identify the presence of fungus spores before symptom appearance. In this paper, we show the results of several shape analysis methods applied to the fungus, the first step to the aimed computer aided vision system, capable to assist the identification process. Experiments and comparative results among the methods are presented in this paper, showing that better results were obtained applying the curvature method

Expansion of different subpopulations of CD26 ?/low T cells in allergic and non-allergic asthmatics

CD26 displays variable levels between effector (TH17 >> TH1 > TH2 > Treg) and naive/memory (memory > naive) CD4(+) T lymphocytes. Besides, IL-6/IL(-)6R is associated with TH17-differentiation and asthma severity. Allergic/atopic asthma (AA) is dominated by TH2 responses, while TH17 immunity might either modulate the TH2-dependent inflammation in AA or be an important mechanism boosting non-allergic asthma (NAA). Therefore, in this work we have compared the expression of CD26 and CD126 (IL-6Ralpha) in lymphocytes from different groups of donors: allergic (AA) and non-allergic (NAA) asthma, rhinitis, and healthy subjects. For this purpose, flow cytometry, haematological/biochemical, and in vitro proliferation assays were performed. Our results show a strong CD26-CD126 correlation and an over-representation of CD26(-) subsets with a highly-differentiated effector phenotype in AA (CD4(+)CD26(-/low) T cells) and NAA (CD4(-)CD26(-) gammadelta-T cells). In addition, we found that circulating levels of CD26 (sCD26) were reduced in both AA and NAA, while loss of CD126 expression on different leukocytes correlated with higher disease severity. Finally, selective inhibition of CD26-mRNA translation led to enhanced T cell proliferation in vitro. These findings support that CD26 down-modulation could play a role in facilitating the expansion of highly-differentiated effector T cell subsets in asthma