Aerosol properties, in-canopy gradients, turbulent fluxes and VOC concentrations at a pristine forest site in Amazonia

Aerosol physical and chemical properties were measured in a forest site in central Amazonia (Cuieiras reservation, 2.61S; 60.21W) during the dry season of 2004 (Aug-Oct). Aerosol light scattering and absorption, mass concentration, elemental composition and size distributions were measured at three tower levels (Ground: 2 m; Canopy: 28 m, and Top: 40 m). For the first time, simultaneous eddy covariance fluxes of fine mode particles and volatile organic compounds (VOC) were measured above the Amazonian forest canopy. Aerosol fluxes were measured by eddy covariance using a Condensation Particle Counter (CPC) and a sonic anemometer. VOC fluxes were measured by disjunct eddy covariance using a Proton Transfer Reaction Mass Spectrometer (PTR-MS). At nighttime, a strong vertical gradient of phosphorus and potassium in the aerosol coarse mode was observed, with higher concentrations at Ground level. This suggests a source of primary biogenic particles below the canopy. Equivalent black carbon measurements indicate the presence of light-absorbing aerosols from biogenic origin. Aerosol number size distributions typically consisted of superimposed Aitken (76 nm) and accumulation modes (144 nm), without clear events of new particle formation. Isoprene and monoterpene fluxes reached respectively 7.4 and 0.82 mg m(-2) s(-1) around noon. An average fine particle flux of 0.05 +/- 0.10 10(6) m(-2) s(-1) was calculated, denoting an equilibrium between emission and deposition fluxes of fine mode particles at daytime. No significant correlations were found between VOC and fine mode aerosol concentrations or fluxes. (C) 2009 Elsevier Ltd. All rights reserved.

Aerosol inorganic composition at a tropical site: Discrepancies between filter-based sampling and a semi-continuous method

The concentrations of the water-soluble inorganic aerosol species, ammonium (NH4+), nitrate (NO3-), chloride (Cl-), and sulfate (SO42-), were measured from September to November 2002 at a pasture site in the Amazon Basin (Rondnia, Brazil) (LBA-SMOCC). Measurements were conducted using a semi-continuous technique (Wet-annular denuder/Steam-Jet Aerosol Collector: WAD/SJAC) and three integrating filter-based methods, namely (1) a denuder-filter pack (DFP: Teflon and impregnated Whatman filters), (2) a stacked-filter unit (SFU: polycarbonate filters), and (3) a High Volume dichotomous sampler (HiVol: quartz fiber filters). Measurements covered the late dry season (biomass burning), a transition period, and the onset of the wet season (clean conditions). Analyses of the particles collected on filters were performed using ion chromatography (IC) and Particle-Induced X-ray Emission spectrometry (PIXE). Season-dependent discrepancies were observed between the WAD/SJAC system and the filter-based samplers. During the dry season, when PM2.5 (D-p <= 2.5 mu m) concentrations were similar to 100 mu g m(-3), aerosol NH4+ and SO42- measured by the filter-based samplers were on average two times higher than those determined by the WAD/SJAC. Concentrations of aerosol NO3- and Cl- measured with the HiVol during daytime, and with the DFP during day- and nighttime also exceeded those of the WAD/SJAC by a factor of two. In contrast, aerosol NO3- and Cl- measured with the SFU during the dry season were nearly two times lower than those measured by the WAD/SJAC. These differences declined markedly during the transition period and towards the cleaner conditions during the onset of the wet season (PM2.5 similar to 5 mu g m(-3)); when filter-based samplers measured on average 40-90% less than the WAD/SJAC. The differences were not due to consistent systematic biases of the analytical techniques, but were apparently a result of prevailing environmental conditions and different sampling procedures. For the transition period and wet season, the significance of our results is reduced by a low number of data points. We argue that the observed differences are mainly attributable to (a) positive and negative filter sampling artifacts, (b) presence of organic compounds and organosulfates on filter substrates, and (c) a SJAC sampling efficiency of less than 100%.

Correlations between chemical composition and provenance of Justino site ceramics by INAA

Instrumental neutron activation analysis (INAA), have been used for the definition of compositional groups of potteries from Justino site, Brazil, according to the chemical similarities of ceramic paste. The outliers were identified by means of robust Mahalanobis distance. The temper effect in the ceramic paste was studied by means of modified Mahalanobis filter. The results were interpreted by means of cluster, principal components, and discriminant analyses. This work provides contributions for the reconstruction of the prehistory of baixo Sao Francisco region, and for the reconstitution of the Brazilian Northeast ceramist population of general frame.

The role in the substrate specificity and catalysis of residues forming the substrate aglycone-binding site of a beta-glycosidase

The relative contributions to the specificity and catalysis of aglycone, of residues E190, E194, K201 and M453 that form the aglycone-binding site of a beta-glycosidase from Spodoptera frugiperda (EC 3.2.1.21), were investigated through site-directed mutagenesis and enzyme kinetic experiments. The results showed that E190 favors the binding of the initial portion of alkyl-type aglycones (up to the sixth methylene group) and also the first glucose unit of oligosaccharidic aglycones, whereas a balance between interactions with E194 and K201 determines the preference for glucose units versus alkyl moieties. E194 favors the binding of alkyl moieties, whereas K201 is more relevant for the binding of glucose units, in spite of its favorable interaction with alkyl moieties. The three residues E190, E194 and K201 reduce the affinity for phenyl moieties. In addition, M453 favors the binding of the second glucose unit of oligosaccharidic aglycones and also of the initial portion of alkyl-type aglycones. None of the residues investigated interacted with the terminal portion of alkyl-type aglycones. It was also demonstrated that E190, E194, K201 and M453 similarly contribute to stabilize ES double dagger. Their interactions with aglycone are individually weaker than those formed by residues interacting with glycone, but their joint catalytic effects are similar. Finally, these interactions with aglycone do not influence glycone binding.

On the apparent lack of preferential site occupancy and electrooxidation of CO adsorbed at low coverage onto stepped platinum surfaces

We report time evolution studies of low coverage CO adsorption (surface hydrogen site blocking < 40%) and oxidative stripping on stepped Pt(776) and Pt(554) surfaces. It was observed that there is no preferential site occupancy for CO adsorption on step or terrace. It is proposed that CO adsorption onto these surfaces is a random process, and after CO adsorption there is no appreciable shift from CO-(111) to CO-(110) sites. This implies that after adsorption, CO molecules either have a very long residence time, or that the diffusion coefficient is much lower than previously thought. After CO electrooxidation the sites released included both terrace (111) and step (110) orientations. For surface hydrogen site blocking > 40%, the lateral interactions might play a role in the preferential CO site occupancy. (C) 2011 Elsevier B.V. All rights reserved.

Simple telemedicine for developing regions: Camera phones and paper-based microfluidic devices for real-time, off-site diagnosis

This article describes a prototype system for quantifying bioassays and for exchanging the results of the assays digitally with physicians located off-site. The system uses paper-based microfluidic devices for running multiple assays simultaneously, camera phones or portable scanners for digitizing the intensity of color associated with each colorimetric assay, and established communications infrastructure for transferring the digital information from the assay site to an off-site laboratory for analysis by a trained medical professional; the diagnosis then can be returned directly to the healthcare provider in the field. The microfluidic devices were fabricated in paper using photolithography and were functionalized with reagents for colorimetric assays. The results of the assays were quantified by comparing the intensities of the color developed in each assay with those of calibration curves. An example of this system quantified clinically relevant concentrations of glucose and protein in artificial urine. The combination of patterned paper, a portable method for obtaining digital images, and a method for exchanging results of the assays with off-site diagnosticians offers new opportunities for inexpensive monitoring of health, especially in situations that require physicians to travel to patients (e.g., in the developing world, in emergency management, and during field operations by the military) to obtain diagnostic information that might be obtained more effectively by less valuable personnel.

International conference site selection criteria : And a case study of Stockholm as an international conference city

The purpose of this thesis is to identify the destination site selection criteria for internationalconferences from the perspectives of the three main players of the conference industry,conference buyers (organizers and delegates) and suppliers. Additionally, the researchidentifies the strengths and weaknesses of the congress cities of Stockholm and Vienna.Through a comparison with Vienna, the top city for hosting international conferences, a roadmap for Stockholm has been designed, to strengthen its congress tourism opportunities, thus,obtaining a higher status as an international congress city. This qualitative research hascombined both primary and secondary data methods, through semi-standardized expertinterviews and secondary studies respectively, to fulfil the study’s aim. The data have beenanalysed by applying the techniques of qualitative content analysis; the secondary dataadopting an inductive approach according to Mayring (2003) while the expert interviewsusing a deductive approach according to Meuser & Nagel (2009). The conclusions of thesecondary data have been further compared and contrasted with the outcomes of the primarydata, to propose fresh discoveries, clarifications, and concepts related to the site selectioncriteria for international conferences, and for the congress tourism industry of Stockholm. Theresearch discusses the discoveries of the site selection criteria, the implications of thestrengths and weaknesses of Stockholm in comparison to Vienna, recommendations forStockholm via a road map, and future research areas in detail. The findings andrecommendation, not only provide specific steps and inceptions that Stockholm as aninternational conference city can apply, but also propose findings, which can aid conferencebuyers and suppliers to cooperate, to strengthen their marketing strategies and developsuccessful international conferences and destinations to help achieve a greater competitiveadvantage.

Reproductive Patterns and Birth Seasonality in a South-American Breeding Colony of Common Marmosets, Callithrix jacchus

SOUSA,M.B.C. et al. Reproductive Patterns and Birth Seasonality in a South-American Breeding Colony of Common Marmosets, Callithrix jacchus. Primates, v.40, n.2, p. 327-336, Apr. 1999.

Development of site-specific sediment quality guidelines for North and South Atlantic littoral zones: Comparison against national and international sediment quality benchmarks

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Sequential histopathology at the Rhipicephalus sanguineus tick feeding site on dogs and guinea pigs

The tick Rhipicephalus sanguineus is a very common parasite of dogs worldwide. Dogs seem unable to acquire resistance against this tick species, whereas guinea pigs demonstrate a very strong resistance following primary infestation. We studied the inflammatory reaction at the R. sanguineus tick feeding site on dogs and guinea pigs during primary and tertiary infestations at different time intervals after attachment. Biopsies were collected after 4, 24, 48 and 96 hours. Changes that were found in all experimental groups included a cone of cement around the mouthparts of the tick, epidermal hyperplasia, edema and inflammatory cell infiltration in the dermis directly underneath the tick attachment site. Dogs reacted to ticks mainly with neutrophils, particularly after repeated exposure. Mast cells and mononuclear leukocytes were also present. Guinea pigs reacted to R. sanguineus mainly with mononuclear cells, eosinophils and basophils. These cells were particularly numerous after repeated exposure to R. sanguineus. Our results suggest that basophils and eosinophils are involved in resistance of guinea pigs to R. sanguineus and that neutrophils in dogs have little effect against this tick species.

Ratios of UV, PAR and NIR components to global solar radiation measured at Botucatu site in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Seasonality of macroalgal communities in a subtropical drainage basin in Paraná state, southern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Structural and functional leaf traits of two Gochnatia species from distinct growth forms in a sclerophyll forest site in Southeastern Brazil

O gênero Gochnatia é comumente encontrado em diferentes fitofisionomias do Cerrado do Estado de São Paulo, crescendo desde ambientes mais abertos até áreas florestais mais fechadas. Aqui foram comparadas a anatomia foliar e alguns parâmetros ecofisiológicos de duas espécies do gênero Gochnatia, uma arbustiva (Gochnatia barrosii Cabrera) e a outra arbórea (Gochnatia polymorpha (Less.) Cabrera), ambas ocorrendo em área de cerradão na Estação Ecológica de Assis, SP. Encontraram-se diferenças estruturais qualitativas entre as espécies, com G. barrosii apresentando folhas anfiestomáticas, com epiderme unisseriada e G. polymorpha apresentando folhas hipoestomáticas, com epiderme múltipla ou hipoderme, na face adaxial. Além disso, as folhas de G. barrosii apresentaram menores valores para a espessura dos tecidos (com exceção da epiderme na face abaxial) e da folha em relação a G. polymorpha. Foram observadas diferenças na assimilação de CO2 tanto em base de área quanto de massa seca foliar, além de diferenças na área foliar específica, sendo esta maior em G. barrosii. Apesar das folhas de G. barrosii possuírem estrutura bem menos escleromorfa do que as folhas de G. polymorpha, não foram encontradas diferenças na eficiência do uso de água. Os resultados sugerem que espécies de formas distintas de crescimento de um mesmo gênero possuem características foliares diferenciadas para lidar com as variações ambientais a que são submetidas.

Effects of intra-hippocampal infusion of WAY-100635 on plus-maze behavior in mice - Influence of site of injection and prior test experience

The positive profile of systemically-administered 5-HT(1A) receptor antagonists in several rodent models of anxiolytic activity suggests an important role for postsynaptic 5-HT(1A) receptor mechanisms in anxiety. To test this hypothesis, we investigated the effects of WAY-100635 microinfusions (0, 0.1, 1.0 or 3.0 mug in 0.2 mul) into the dorsal (DH) or ventral (VH) hippocampus an behaviours displayed by male Swiss-Webster mice in the elevated plus-maze. As prior experience is known to modify pharmacological responses in this test, the effects of intra-hippocampal infusions were examined both in maze-naive and maze-experienced subjects. Test videotapes were scored for conventional indices of anxiety (% open arm entries/time) and locomotor activity (closed arm entries), as well as a range of ethological measures (e.g. risk assessment). In maze-naive mice, intra-VH (but not intra-M) infusions of WAY-100635 (3.0 mug but not lower doses) increased open arm exploration and reduced risk assessment. These effects were observed in the absence of significant changes in locomotor activity. In contrast, neither intra-VH nor intra-DH infusions of WAY-100635 altered the behaviour of maze-experienced mice. These Findings suggest that postsynaptic 5-HT(1A) receptors in the ventral (but not dorsal) hippocampus play a significant role both in the mediation of plus-maze anxiety in mice and in experientially-induced alterations in responses to this test. (C) 2002 Elsevier B.V. BY All rights reserved.