Composition and functionality of bacterioplankton communities in marine coastal zones adjacent to finfish aquaculture.

Finfish aquaculture is a fast-growing primary industry and is increasingly common in coastal ecosystems. Bacterioplankton is ubiquitous in marine environment and respond rapidly to environmental changes. Changes in bacterioplankton community are not well understood in semi-enclosed stratified embayments. This study aims to examine aquaculture effects in the composition and functional profiles of the bacterioplankton community using amplicon sequencing along a distance gradient from two finfish leases in a marine embayment. Results revealed natural stratification in bacterioplankton associated to NOx, conductivity, salinity, temperature and PO4. Among the differentially abundant bacteria in leases, we found members associated with nutrient enrichment and aquaculture activities. Abundant predicted functions near leases were assigned to organic matter degradation, fermentation, and antibiotic resistance. This study provides a first effort to describe changes in the bacterioplankton community composition and function due to finfish aquaculture in a semi-enclosed and highly stratified embayment with a significant freshwater input.

Convergent evolution of pain-inducing defensive venom components in spitting cobras.

Convergent evolution provides insights into the selective drivers underlying evolutionary change. Snake venoms, with a direct genetic basis and clearly defined functional phenotype, provide a model system for exploring the repeated evolution of adaptations. While snakes use venom primarily for predation, and venom composition often reflects diet specificity, three lineages of cobras have independently evolved the ability to spit venom at adversaries. Using gene, protein, and functional analyses, we show that the three spitting lineages possess venoms characterized by an up-regulation of phospholipase A2 (PLA2) toxins, which potentiate the action of preexisting venom cytotoxins to activate mammalian sensory neurons and cause enhanced pain. These repeated independent changes provide a fascinating example of convergent evolution across multiple phenotypic levels driven by selection for defense.

Breeding objectives and selection criteria of a participatory community-based breeding programme of goats and sheep.

The absence of formal markets and the large variability of genetic groups and production systems of goats and sheep in developing countries hinder the implementation of traditional breeding programmes. Community-based breeding programmes (CBBP) for these species have been shown to be effective in these countries. In these programmes, the definition of the objectives and criteria of selection is done in a participatory way, which takes into account the desires and needs of the local farmers. We aimed to define the objectives and criteria of a CBBP for goats and sheep in the Inhamuns region, Ceará, Brazil, using a participatory rural appraisal (PRA). This methodology, which consist in an approach that aims to incorporate the knowledge and opinions of rural people in the planning and management of development projects and programmes, was performed in seven districts of two towns of the region (Tauá and Parambu). One hundred twenty-two farmer families participated in the survey. The PRA was able to provide important information, and its results showed that breeders of this region keep flocks of goats and sheep for social, economic and cultural benefits. In order of importance, the main objectives for goat farming were personal fulfilment (PERF), food source for family (FSF), income generation (INCG), savings (SAV) and cultural/family traditions (CULT), while for sheep farming were CULT, FSF, SAV, PERF and INCG. Disease resistance (RDI), adaptability (ADP), fertility (FERT), growth rate (GRA), host resistance of worms (HRW), body conformation (BC), temperament (TEM), longevity (LONG), body size (BSIZ), age at first kidding (AFK) and milk yield (MIY) were the main selection criteria that farmers use for goats. The most important selection criteria used for selecting sheep were ADP, RDI, HRW, GRA, FERT, LONG, BC, BS and age at first lambing. According to these objectives and criteria, the CBBP must consider the adaptation of the animals to the climate and management conditions of the region, the resistance to diseases and productive performance.

Biosurfactant production by yeasts from different types of soil of the South Shetland Islands (Maritime Antarctica).

AIM: To screen and identify a potential biosurfactant-producing yeast strain isolated from Antarctic soil and to evaluate the fermentation process kinetics of the most promising strain on biosurfactant production using glycerol as carbon source. METHODS AND RESULTS: From the 68 isolated yeast strains, 11 strains were able to produce biosurfactants after Emulsification Index (E.I.) and Drop Collapse tests, reaching an E.I. higher than 10%. Strain 1_4.0 was the best producer, identified as Candida glaebosa based on molecular analysis. Yeast was cultivated in a medium composed of glycerol supplemented with yeast extract for 120 h to determine the process kinetics. The increased C/N ratio affected yeast growth and biosurfactant production. Biosurfactant release was associated with the end of exponential and beginning of the stationary growth phases. Results indicated an E.I. of 30% at the end of the fermentation. CONCLUSIONS: The feasiability of C. glaebosa to produce biosurfactant from a low-cost medium cultivation shows a great impact on the development of bioresource in the Antarctica terrestrial environment. SIGNIFICANCE AND IMPACT OF THE STUDY: Although the diversity of psychrophilic/psychrotolerant micro-organisms from Antarctica has been the preferred subject of study by microbiologists, terrestrial microfungal communities are scarcely investigated and literature about the biotechnological potential of such micro-organisms should cover important biomolecules in addition to cold-adapted enzymes. In the present study, for the first time, the Maritime Antarctica environment was screened as a novel source of biosurfactants produced by micro-organisms.

Physalis angulata induces death of promastigotes and amastigotes of Leishmania (Leishmania) amazonensis via the generation of reactive oxygen species.

Leishmaniasis are a neglected group of emerging diseases that have been found in 98 countries and are caused by protozoa of the genus Leishmania. The therapy for leishmaniasis causes several side effects and leads to drug-resistant strains. Natural products from plants have exhibited activities against Leishmania in various experimental models. Physalis angulata is a widely used plant in popular medicine, and in the literature it has well-documented leishmanicidal activity. However, its mechanism of action is still unknown. Thus, this study aims to evaluate the mechanism driving the leishmanicidal activity of an aqueous extract of P. angulata root (AEPa). AEPa was effective against both promastigotes and intracellular amastigote forms of Leishmania amazonensis. This effect was mediated by an increase of reactive oxygen species (ROS), but not of nitric oxide (NO). The increased production of ROS induces cell death by phenotypes seems by apoptosis cell death in Leishmania, but not autophagy or necrosis. In addition, morphological analysis of macrophages showed that AEPa induced a high number of cytoplasmic projections, increased the volume of cytoplasm and number of vacuoles, caused cytoskeleton alterations and resulted in high spreading ability. AEPa also promoted superoxide anion (O2(-)) production in both uninfected macrophages and those infected with Leishmania. Therefore, these results revealed that AEPa causes cell death by phenotypes seems by apoptosis cell death in L. amazonensis and modulates macrophage activation through morphofunctional alterations and O2(-) generation to induce Leishmania death.

Birefringence-induced wavelength mismatch between the polarization rotation and resonant modes in magnetophotonic structures containing nematic layers.

The present work is devoted to the study of spectral characteristics of normal incident light transmitted by a multilayered structure composed of an alternated sequence of nematic and magnetic layers presenting a central magneto-optical defect. Using the Berreman 4 × 4 matrix formalism, we numerically obtain the transmission spectrum and the polarization rotation angle of the system as a function of the nematic optical axis direction. Our results reveal the emergence of a shift between the wavelengths of the resonant mode and polarization rotation angle, which strongly depends on the birefringence of the nematic layers. In particular, we show the existence of distinct regimes for the wavelength mismatch between the transmission of resonant modes and the maximum polarization rotation angle, which are governed by the ordinary and extraordinary refractive indices of nematic layers. The mechanism behind such shift is discussed under the light of propagation eigenmodes for a medium presenting circular and linear birefringence. The effects associated with the defect thickness are also analyzed.

Extraordinary magnetoresistance in graphite: experimental evidence for the time-reversal symmetry breaking.

We report a highly anisotropic in-plane magnetoresistance (MR) in graphite that possesses in-plane parallel line-like structural defects. In a current direction perpendicular to the line defects (LD), MR is negative and linear in low fields with a crossover to a positive MR at higher fields, while in a current direction parallel to LD, we observed a giant super-linear positive MR. These extraordinary MRs are respectively explained by a hopping magnetoresistance via non-zero angular momentum orbitals, and by the magnetoresistance of inhomogeneous media. The linear negative orbital MR is a unique signature of the broken time-reversal symmetry (TRS). We discuss the origin of the disorder-induced TRS-breaking in graphite.

Genotoxicity in Oreochromis niloticus (Cichlidae) induced by Microcystis spp bloom extract containing microcystins.

Studies of genotoxicity in fish caused by cyanobacterial extracts containing microcystins (MCs) can be useful in determining their carcinogenic risk due to a genotoxic mechanism. An extract of cyanobacterial Microcystis ssp, containing MC-LR and -LA from a bloom collected in a eutrophic lake, showed genotoxicity to Oreochromis niloticus. DNA damage (comet assay) was significantly induced in peripheral erythrocytes with both tested concentrations of 6.90 µg kg(-1) bw and 13.80 µg kg(-1) bw through intraperitoneal injection (ip). There was no micronucleus induction after ip injection at concentrations of 6.90 µg kg(-1) bw and 13.80 µg kg(-1) bw. Body exposure resulted in micronucleus induction and DNA damage only at the highest tested concentrations of 103.72 µg L(-1). Thus, comet assay and ip injection revealed the highest levels of the genotoxicity of MCs. Apoptosis-necrosis test carried out at concentrations of 6.90 µg kg(-1) bw and 13.80 µg kg(-1) bw revealed that at low concentrations more apoptosis than necrosis occurred. At higher concentrations more necrosis than apoptosis occurred.

Resonant modes in cholesteric liquid crystals with a gaussian pitch profile.

In this paper, we investigate the spectral properties of a cholesteric film presenting a pitch profile with a gaussian deformation. Using the Berreman 4 × 4 matrix formalism, we numerically obtain the transmission spectrum at normal and oblique light incidence as a function of width and the position of the deformation. Our results reveal that a pair of resonant modes emerges inside the main stop band of the transmission spectrum as the width of the deformation becomes comparable to the helical pitch length. The mechanism behind the emergence of the resonant modes is discussed. The case of a pitch profile with multiple gaussian deformations is also analyzed. At this configuration, a crossover from single to multiple band-gap pattern can be observed in the transmission spectrum, depending on the deformation parameters.

Searching for the fractional quantum Hall effect in graphite.

Measurements of basal plane longitudinal rho(b)(B) and Hall rho(H)(B) resistivities were performed on highly oriented pyrolytic graphite samples in a pulsed magnetic field up to B=50 T applied perpendicular to graphene planes, and temperatures 1.5 K30 T and for all studied samples, we observed a sign change in rho(H)(B) from electron- to holelike. For our best quality sample, the measurements revealed the enhancement in rho(b)(B) for B>34 T (T=1.8 K), presumably associated with the field-driven charge density wave or Wigner crystallization transition. In addition, well-defined plateaus in rho(H)(B) were detected in the ultraquantum limit revealing possible signatures of the fractional quantum Hall effect in graphite.

Thie expression of an intraspecific aggressive reaction in the face of a stressor agent alters the immune response in rats.

The repercussion on the immune response of the expression of intraspecific aggressiveness in the face of a stressor agent was investigated in rats. Ninety-day-old animals were divided into three groups: the control group (only immunological measurements were performed), the foot-shock (FS) (animals individually receiving FS), and the intraspecific aggressive response (IAR) group (animals receiving FS and presenting IAR). For immunological measurements, blood samples were collected promptly at 7 and 15 days after FS or IAR. The FS reduced the total leukocyte amount presented. However, aggressiveness triggered not only reduction of the leukocytes, but also lymphocyte decrease and neutrophil increase. Moreover, an elevation in total leukocytes associated with an increase in the humoral immune response was also observed one week after IAR. In this study, the expression of intraspecific aggressiveness in the face of a stressor seemed to activate the immune system and to potentiate the antigen specific humoral response.

The expression of an intraspecific aggressive reaction in the face of a stressor agent alters the immune response in rats

A repercussão sobre a resposta imune da expressão da agressividade intra-específica diante de um estressor foi investigada em ratos. Aos 90 dias de vida, os animais foram divididos em três grupos: grupo-controle (foram realizadas apenas mensurações imunológicas), choque nas patas (FS) (os animais receberam FS individualmente) e grupo resposta agressiva intra-específica (IAR) (os animais receberam FS e apresentaram IAR). Para as medições imunológicas, amostras de sangue foram coletadas imediatamente, 7 e 15 dias após FS ou IAR. O FS reduziu a quantidade total de leucócitos. Contudo, a agressividade foi acompanhada, além da redução do número de leucócitos, por diminuição de linfócitos e aumento de neutrófilos. Além disso, também foi observada elevação no número de leucócitos associada a aumento na resposta imune humoral uma semana após as IAR. Neste estudo, a expressão da agressividade intra-específica diante de um estressor parece ativar o sistema imune e potencializar a resposta humoral antígeno específica.

Fecundity and fertility of Macrobrachium amazonicum (Crustacea, Palaemonidae).

In Brazil, studies with native freshwater prawn species were discontinued due to great importance of Macrobrachium rosenbergii. Therefore, it is necessary to continue investigations about our species, in order to develop technology adequate to our reality and in a future allow prawn farmers to culture other species. The aim of this study was to determine the fecundity and fertility of Macrobrachium amazonicum captured monthly from June 1999 to June 2001 from Jaguaribe River, Itaiçaba, Ceará, Brazil. Prawns were collected using fishing net and transferred at Biological Science Laboratory, Ceara State University (Fortaleza, Ceará, Brazil). Among the ovigerous M. amazonicum females, 60 were randomly selected to determine fecundity. The eggs adhered to the pleopods were taken out and they were then placed in a Gilson solution, and then stored in alcohol 70%. Individual fecundity was determined from the total egg counting, using a stereoscopic microscope. To determine fertility, ovigerous M. amazonicum females were stored in individual 10 L-glass tanks maintained under strong aeration. After the hatching, the larvae were siphoned and counted. The data referring to total length and weight of all the females, storage date, coloration and number of eggs, weight and coloration of gonad and number of hatched larvae were noted. With respect to average fecundity (F) by length classes, the lowest and highest number of eggs observed was 696 and 1,554, respectively. As for fecundity by weight classes, the lowest number of eggs observed was 760 and the highest, 1,690. The highest number of eggs observed individually per hatching was 2,193. Average fecundity/total length (L) and average fecundity/total weight (W) may be expressed by a linear relationship. The adjusted equations are: F = -411.6 + 203.1 L (p < 0.0001) and F = 566.4 + 157.3 W (p < 0.0001), respectively. In the analysis of average fertility (N) per length classes, the lowest and highest number of larvae observed was 374 and 1,301, respectively. With respect to fertility per weight classes, the lowest number of larvae was 581 and the highest, 1,391. In this work, the maximum number of larvae observed per hatching for females kept in laboratory was 2,594. Average fertility/total length and average fertility/total weight may be expressed by a linear relationship. The adjusted equations are: N = -1042.7 + 264.9 L (p < 0.0002); N = 384.1 + 160.3 W (p < 0.003). From these results we can deduced that fecundity and fertility of M. amazonicum are lower than ones commercial species, never-the-less it can be captured during all year long. The number of captured prawns was large in the months whose level of water was low; the inverse was observed in the months that the river was with a high volume of water.

Fecundity and fertility of Macrobrachium amazonicum (Crustacea, Palaemonidae)

No Brasil, os estudos com espécies nativas de camarões de água doce foram interrompidos em decorrência da importação de Macrobrachium rosenbergii. Entretanto, é necessário continuar as investigações com nossas espécies, com o objetivo de desenvolver tecnologia adequada à nossa realidade e, em um futuro próximo, de permitir aos carcinicultores outras opções para cultivo. O objetivo deste estudo foi determinar a fecundidade e a fertilidade de Macrobrachium amazonicum, capturado mensalmente de junho de 1999 a junho de 2001, no Rio Jaguaribe, em Itaiçaba, Ceará, Brasil. Após a coleta, os camarões foram transportados para o Laboratório de Ciências Biológicas, na Universidade Estadual do Ceará (Fortaleza, Ceará, Brasil). Foram selecionadas, aleatoriamente, 60 fêmeas ovígeras para a determinação da fecundidade. Os ovos aderidos aos pleópodes foram retirados, colocados em Solução de Gilson e estocados em álcool 70%. A fecundidade individual foi determinada a partir da contagem total dos ovos de cada fêmea. Para determinar a fertilidade, fêmeas ovígeras de M. amazonicum foram estocadas individualmente em aquários de vidro de 10 L. Após a eclosão, as larvas foram sifonadas e contadas. Os dados referentes ao comprimento e peso total de todas as fêmeas, à data de estocagem, à coloração e número de ovos, ao peso e coloração das gônadas e ao número de larvas eclodidas foram registrados. O menor e o maior número de ovos observados por classes de comprimento foram de 696 e 1.554, respectivamente. Para a fecundidade por classes de peso, o menor número de ovos observados foi de 760 e o maior, de 1.690. O número mais elevado de ovos observados individualmente por desova foi 2.193. Fecundidade média/comprimento total (L) e fecundidade média/peso total (W) podem ser expressas por relação linear. As equações ajustadas são F = û411,6 + 203,1 L (p < 0,0001) and F = 566,4 + 157,3 W (p < 0,0001), respectivamente. Na análise da fertilidade (N) por classes de comprimento, o menor e o maior número de larvas observados foram 374 e 1.301, respectivamente. Quanto à fertilidade por classes de peso, o menor número de larvas foi de 401 e o maior, de 1.231. Neste trabalho, o número máximo de larvas observado por desova para fêmeas mantidas em laboratório foi de 2.594. Fertilidade média/comprimento total...

The use of ultrasonic guided waves and wavelets analysis in pipe inspection.

One of the main applications of guided waves is for pipe inspection, since its one-dimensional geometry allows inspecting long distances in a short time. As with most configurations (frequency, thickness) ultrasonic waves with many modes of propagation are generated, recent research focuses mostly on the generation and reception of specific modes, mainly by means of sophisticated arrays of transducers. In this paper this problem is addressed with a different approach, by processing ultrasonic signals with a low signal/noise ratio acquired with a single transducer in an pulse-echo configuration. In order to improve the evaluation of results, frequency bandpass filters and wavelet analysis were tested. Results showed that even when very noisy signals are utilized, signal processing improve the signal/noise (S/N) ratio up to 12 dB approximately and enhance the analysis of the results, thus demonstrating its usefulness.

Reentrant metallic behavior of graphite in the quantum limit.

Magnetotransport measurements performed on several well-characterized highly oriented pyrolitic graphite and single crystalline Kish graphite samples reveal a reentrant metallic behavior in the basal-plane resistance at high magnetic fields, when only the lowest Landau levels are occupied. The results suggest that the quantum Hall effect and Landau-level-quantization-induced superconducting correlations are relevant to understand the metalliclike state(s) in graphite in the quantum limit.

Indication of superconductivity at 35 K in graphite-sulfur composites.

We report magnetization measurements performed on graphite-sulfur composites which demonstrate a clear superconducting behavior below the critical temperature T(c0) = 35 K. The Meissner-Ochsenfeld effect, screening supercurrents, and magnetization hysteresis loops characteristic of type-II superconductors were measured. The results indicate that the superconductivity occurs in a small sample fraction, possibly related to the sample surface.

[Hypocholesterolemic effect of naringin and rutin flavonoids]. / Efeito hipolipidêmico dos flavonóides naringina e rutina.

Flavonoids are pigments fenolics of plants that possess several biological activities, and many of these are associated with prevention of chronic diseases as cancer and hyperlipidemia. This work had as objective evaluates the effect of the flavonoids naringin and rutin on the metabolism lipidic of chicks hypercholesterolemic. In agreement with the results it can be observed that naringin and rutin reduced the levels of total cholesterol significantly, cholesterol-LDL, cholesterol-VLDL and triglycerols, not presenting, however, reductions in the levels of cholesterol-HDL.

[Continuing nursing education at the hospital-school: a diagnosis]. / Educação continuada em enfermagem no hospital-escola: um diagnóstico.

The interest of the authors in developing this study was based on the fact that the continued education courses offered at a teaching hospital, located in the southern region of Brazil, always happened in an empirical way, without first carrying out a diagnosis which permits the development of a program related to the needs of the clientele. The quanti-qualitative study, composed by both open and multiple choices questions, was applied to 70% of the nursing staff, from the period of November of 1998 to January of 1999. Analysis of the data allowed the authors to identify the necessary steps for the implementation of a Continued Education Service.