A comparative study of cleaning activity of two reef fishes at Fernando de Noronha Archipelago, tropical West Atlantic

Cleaner fishes are usually classified as obligate or facultative cleaners according to their diet and the extent to which their nutritional requirements in the different ontogenetic stages are gained from cleaning. While obligate cleaners clean throughout their lives and ingest mainly food taken from the clients` body surface, facultative cleaners clean only as juveniles and have a broader diet. In addition, some facultative cleaners may experience a relatively higher predation risk, and thus rarely interact with piscivorous fishes. Despite these acknowledged differences, there are very few studies that compare cleaning activity of obligate and facultative cleaners within the same area. Cleaning activity of the obligate cleaner goby Elacatinus cf. randalli and the facultative cleaner wrasse Thalassoma noronhanum were comparatively examined at Fernando de Noronha Archipelago, tropical West Atlantic. The client assemblage attended by the two cleaners differed, as the goby attended a slightly greater diversity of species (22), mostly piscivores and zoobenthivores, and the wrasse attended fewer species (19), mostly planktivores. Chromis multilineata was the most common client species of both cleaners, although body size (which is expected to be positively correlated to clients` ectoparasite load) of C. multilineata individuals attended by the goby was larger than that of the individuals attended by the wrasse. Despite such differences, T. noronhanum showed a surprisingly species-rich client assemblage when compared with other cleaners of the genus Thalassoma. In addition, the frequency and time spent on cleaning interactions, as well as the number of client species attended per 10-min period, was similar for both cleaner species, which indicate that they have important yet complimentary ecological roles in the reef community at Fernando de Noronha Archipelago.

Strategies to Optimize Biosensors Based on Impedance Spectroscopy to Detect Phytic Acid Using Layer-by-Layer Films

Impedance spectroscopy has been proven a powerful tool for reaching high sensitivity in sensor arrays made with nanostructured films in the so-called electronic tongue systems, whose distinguishing ability may be enhanced with sensing units capable of molecular recognition. In this study we show that for optimized sensors and bio-sensors the dielectric relaxation processes involved in impedance measurements should also be considered, in addition to an adequate choice of sensing materials. We used sensing units made from layer-by-layer (LbL) films with alternating layers of the polyeletrolytes, poly(allylamine) hydrochloride (PAH) and poly(vinyl sulfonate) (PVS), or LbL films of PAH alternated with layers of the enzyme phytase, all adsorbed on gold interdigitate electrodes. Surprisingly, the detection of phytic acid was as effective in the PVS/PAH sensing system as with the PAH/phytase system, in spite of the specific interactions of the latter. This was attributed to the dependence of the relaxation processes on nonspecific interactions such as electrostatic cross-linking and possibly on the distinct film architecture as the phytase layers were found to grow as columns on the LbL film, in contrast to the molecularly thin PAH/PVS films. Using projection techniques, we were able to detect phytic acid at the micromolar level with either of the sensing units in a data analysis procedure that allows for further optimization.

A geochemical and lead isotopic record from a small pond in a remote equatorial island, Fernando de Noronha, Brazil

A 72 cm long core was collected from Lagoa da Viracao (LV), a small poind in the Fernando de Noronha island, northern Brazil. Sediments from the lower section of the core (20-72 cm depth) contain essentially mineral matter, while in the upper section (0-20 cm depth) mineral matter is mixed with organic matter. Lithogenic conservative elements - Si, Al, Fe, Ti, Co, Cr, Cu, Ba, Ga, Hf, Nb, Ni, Y, V, Zn, Zr and REE - exhibit remarkably constant values throughout the core, with concentrations similar to those of the bedrock. The vertical distribution of soluble elements - Ca, Mg, Na, K, P, Mn and Sr - is also homogeneous, but these elements are systematically depleted in relation to the bedrock. LOI, TOC, Br, Se, Hg and Pb, although showing nearly constant values in the lower section of the core, are significantly enriched in the upper section. The concentration profiles of Br and Se suggest that they may be accounted for by natural processes, related to the slight affinity of these elements for organic matter. On the other hand, the elevated levels of Hg and Pb in recent sediments may be explained by their long-range atmospheric transport and deposition. Furthermore, the isotopic composition of Pb clearly indicates that anthropogenic sources contributed to the Pb burden in the uppermost pond sediments.

Digestive physiology and characterization of digestive cathepsin L-like proteinase from the sugarcane weevil Sphenophorus levis

Sugarcane is an important crop that has recently become subject to attacks from the weevil Sphenophorus levis, which is not efficiently controlled with chemical insecticides. This demands the development of new control devices for which digestive physiology data are needed. In the present study, ion-exchange chromatography of S. levis whole midgut homogenates, together with enzyme assays with natural and synthetic substrates and specific inhibitors, demonstrated that a cysteine proteinase is a major proteinase, trypsin is a minor one and chymotrypsin is probably negligible. Amylase, maltase and the cysteine proteinase occur in the gut contents and decrease throughout the midgut; trypsin is constant in the entire midgut, whereas a membrane-bound aminopeptidase predominates in the posterior midgut. The cysteine proteinase was purified to homogeneity through ion-exchange chromatography. The purified enzyme had a mass of 37 kDa and was able to hydrolyze Z-Phe-Arg-MCA and Z-Leu-Arg-MCA with k(cat)/K(m) values of 20.0 +/- 1.1 mu M(-1) s(-1) and 30.0 +/- 0.5 mu M(-1) s(-1), respectively, but not Z-Arg-Arg-MCA. The combined results suggest that protein digestion starts in the anterior midgut under the action of a cathepsin L-like proteinase and ends on the surface of posterior midgut cells. All starch digestion takes place in anterior midgut. These data will be instrumental to developing S. levis-resistant sugarcane. (C) 2011 Elsevier Ltd. All rights reserved.

Quantification of N-acetylcysteine in pharmaceuticals using cobalt phthalocyanine modified graphite electrodes

Flow injection analysis (FIA) with amperometric detection was employed for the quantification of N-acetylcysteine (NAC) in pharmaceutical formulations, utilizing an ordinary pyrolytic graphite (OPG) electrode modified with cobalt phthalocyanine (CoPc). Cyclic voltammetry was used in preliminary studies to establish the best conditions for NAC analysis. In FIA-amperometric experiments the OPG-CoPc electrode exhibited sharp and reproducible current peaks over a wide linear working range (5.0 x 10(-5)-1.0 x 10(-3) mol L(-1)) in 0.1 mol L(-1) NaOH solution. High sensitivity (130 mA mol(-1) cm(2)) and a low detection limit (9.0 x 10(-7) mol L(-1)) were achieved using the sensor. The repeatability (R.S.D.%) for 13 successive flow injections of a solution containing 5.0 x 10(-4) mol L(-1) NAC was 1.1%. The new procedure was applied in analyses of commercial pharmaceutical products and the results were in excellent agreement with those obtained using the official titrimetric method. The proposed amperometric method is highly suitable for quality control analyses of NAC in pharmaceuticals since it is rapid, precise and requires much less work than the recommended titrimetric method. (C) 2010 Elsevier B.V. All rights reserved.

Development of secondary palate requires strict regulation of ECM remodeling: sequential distribution of RECK, MMP-2, MMP-3, and MMP-9

We have evaluated RECK (reversion-inducing-cysteine-rich protein with Kazal motifs), MMP-2 (matrix metalloproteinase-2), MMP-3, and MMP-9 involvement during palate development in mice by using various techniques. Immunohistochemical features revealed the distribution of RECK, MMP-2, and MMP-3 in the mesenchymal tissue and in the midline epithelial seam at embryonic day 13 (E13), MMPs-2, -3, and -9 being particularly expressed at E14 and E14.5. In contrast, RECK was weakly immunostained at these times. Involvement of MMPs was validated by measuring not only their protein expression, but also their activity (zymograms). In situ hybridization signal (ISH) for RECK transcript was distributed in mesenchymal and epithelial regions within palatal shelves at all periods evaluated. Importantly, the results from ISH analysis were in accord with those obtained by real-time polymerase chain reaction. The expression of RECK was found to be temporally regulated, which suggested possible roles in palatal ontogeny. Taken together, our results clearly show that remodeling of the extracellular matrix is finely modulated during secondary palate development and occurs in a sequential manner.

A New Indirect Electrochemical Method for Determination of Ozone in Water Using Multiwalled Carbon Nanotubes

A new electrochemical methodology has been developed for the detection of ozone using multiwalled carbon nanotubes (MWCNT). The method presented here is based on the reaction of ozone with indigo blue dye producing anthranilic acid (ATN). The electrochemical profile of ATN on an electrode of glassy carbon (GC) modified with MWCNT showed an oxidation peak potential at 750 mV vs. Ag/AgCl. An analytical method was developed using differential pulse voltammetry (DPV) to determine ATN in a range of 50-400 nmol L(-1), with a detection limit of 9.7 nmol L(-1). Ozonated water samples were successfully analyzed by GC/MWCNT electrode and the recovery procedure yielded values between of 96.5 and 102.3%.

En rörelse formas : bildandet av Dalarnas mejeriförening 1931-1933

Syftet med uppsatsen är att kartlägga bildandet av Dalarnas mejeriförening med hjälp avfrågeställningar angående hur, varför och av vilka personer föreningen skapades samt hurorganisationen Dalarnas mejeriförening kan tolkas med teorier om sociala rörelser och sociala nätverk. Undersökningen baserar sig på källmaterial från Dalarnas mejeriförening ochKopparbergs läns hushållningssällskap. Resultatet av undersökningen är att Dalarnasmejeriförening kan anses vara en social rörelse som bildades för att kontrollera mejerihanteringen i Dalarna. Dalarnas mejeriförening implementerade en omorganisering ilinje med den kooperationsteoretiska rörelseteorin. Rörelsens organisation var baserad på enregelorienterad tolkning av kooperationsprinciperna och rörelseideologin på envärdeorienterad tolkning av desamma. Rörelsens mobiliseringsstruktur var god på grund av en fördelaktig politisk möjlighetsstruktur och framgångsrika nätverksrelationer både inom rörelsen men också mellan rörelsen och andra jordbruksorganisationer.

"¡Cáncer es una mujer pegada como una sanguijuela sesenta años succionándole el alma!" : Un examen de los rasgos misóginos en la novela El desbarrancadero de Fernando Vallejo

El desbarrancadero, published in 2001 by Colombian author Fernando Vallejo is foremost a moving story about brotherly love, but it is also a highly critical novel that lashes out on a number of phenomena such as the catholic church, the Pope and the very idea of religion. It also addresses the poverty of Colombia, its corrupt politicians, the drug trade, viral diseases and animal abuse to mention a few more subjects. This essay however, does not aim to explore any of the above mentioned matters but rather examine how women are portrayed in this novel. The objective of this investigation, based on feminist theories, is to establish the very clear presence of misogyny attitudes.

As estratégias de administração das políticas públicas de educação na cidade do Rio de Janeiro entre 1922 e 1935

O artigo busca explanar as estratégias de administração da educação pública desenvolvidas na cidade do Rio de Janeiro entre 1922 e 1935. Examinando as políticas públicas de educação, durante as administrações de Antônio Carneiro Leão (1922-1926), Fernando de Azevedo (1927-1930) e Anísio Teixeira (1931-1935), apresenta as mudanças ocorridas na organização da Diretoria Geral de Instrução Pública. Na complexa rede de instituições e saberes, visando reformar a estrutura administrativa da educação, a ampliação das agências de Estado e a especialização dos serviços de educação constituem um importante recurso político.

Memórias de jornalistas: narrativas de profissionais da grande imprensa sobre a eleição, o governo e o impeachment de Fernando Collor

A presente pesquisa tem por tema as vivências de jornalistas na cobertura do “período Collor”, desde a eleição presidencial em 1989 até o processo de impeachment em 1992. Origina-se do questionamento sobre quais recordações jornalistas, que, na época, atuavam em grandes órgãos de imprensa, guardam na memória acerca daquele importante período da história recente do país. Busca, com isso, resgatar a memória do período sob o ponto de vista dos jornalistas convidados a participarem deste estudo, assim como identificar experiências e vivências que possam contribuir para uma melhor compreensão do fazer jornalístico nos últimos anos do século XX. Para tanto, parte do registro de Narrativas Orais de Histórias de Vida, baseada nos métodos da História Oral, que valoriza os indivíduos e suas respectivas histórias de vida como forma de recuperar o passado aos olhos do tempo presente, por meio de lembranças narradas oralmente. A pesquisa tem como fatores de inovação a busca por uma dimensão subjetiva nos estudos científicos da Comunicação Social e as transformações comunicacionais vividas por uma geração de jornalistas, representada pela comunidade estudada. A metodologia adotada permitiu uma construção histórica do período, a partir das memórias dos entrevistados, assim como possibilitou melhor compreender o fazer jornalístico de uma geração. Conclui-se, assim, com base nas narrativas, que os acontecimentos do “período Collor” ajudam a evidenciar os complexos elementos que interferem no exercício cotidiano do jornalismo, chamando a atenção, sobretudo, para as constantes tensões provocadas pelo contraditório discurso que propaga o mito da isenção jornalística e as decisões tomadas no ato da edição; a forma como o jornalista constrói o mundo que encontra ao produzir a notícia e as escolhas subjetivas feitas ao longo da vida profissional, que os constitui como sujeitos da ação do jornalismo.