199 research outputs found

    The Transversarium-Bifurcatus Zone boundary at Rocha (Peral area, East-Central Algarve, Portugal)

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    This paper represents the first detailed study of the Transversarium-Bifurcatus Zone boundary in the Algarve. The boundary studied in the Peral area is associated with a stratigraphic discontinuity, whose hiatus partially affects the Transversarium-Bifurcatus Zones. A discontinuity was also recognized in the Bifurcatus-Birnammatum Zone boundary, which can be correlated with the traces of a Type II unconformity, which separates cycles 4.3-4.4 in HAQ et al. (1987), present on the South Iberian palaeomargin. An analysis was made of the ecostratigraphic evolution in the interval between the uppermost Transversarium Zone and the lower part of the Bimammatum Zone on the basis of the faunal spectra obtained. We conclude that ammonites are the most tolerant cephalopods to the ecological stress caused by the increase of inflows and the decrease of the shelf's ecospace. Benthic fauna decreased considerably in these conditions. A relatively abundant and diversified fauna ofDichotomoceras is noteworthy among the ammonites collected, as this genus was previously little known in the Algarve

    Evidence of suppression of onchocerciasis transmission in the Venezuelan Amazonian focus.

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    BACKGROUND: The World Health Organization (WHO) has set goals for onchocerciasis elimination in Latin America by 2015. Most of the six previously endemic countries are attaining this goal by implementing twice a year (and in some foci, quarterly) mass ivermectin (Mectizan®) distribution. Elimination of transmission has been verified in Colombia, Ecuador and Mexico. Challenges remain in the Amazonian focus straddling Venezuela and Brazil, where the disease affects the hard-to-reach Yanomami indigenous population. We provide evidence of suppression of Onchocerca volvulus transmission by Simulium guianense s.l. in 16 previously hyperendemic Yanomami communities in southern Venezuela after 15 years of 6-monthly and 5 years of 3-monthly mass ivermectin treatment. METHODS: Baseline and monitoring and evaluation parasitological, ophthalmological, entomological and serological surveys were conducted in selected sentinel and extra-sentinel communities of the focus throughout the implementation of the programme. RESULTS: From 2010 to 2012–2015, clinico-parasitological surveys indicate a substantial decrease in skin microfilarial prevalence and intensity of infection; accompanied by no evidence (or very low prevalence and intensity) of ocular microfilariae in the examined population. Of a total of 51,341 S. guianense flies tested by PCR none had L3 infection (heads only). Prevalence of infective flies and seasonal transmission potentials in 2012–2013 were, respectively, under 1 % and 20 L3/person/transmission season. Serology in children aged 1–10 years demonstrated that although 26 out of 396 (7 %) individuals still had Ov-16 antibodies, only 4/218 (2 %) seropositives were aged 1–5 years. CONCLUSIONS: We report evidence of recent transmission and morbidity suppression in some communities of the focus representing 75 % of the Yanomami population and 70 % of all known communities. We conclude that onchocerciasis transmission could be feasibly interrupted in the Venezuelan Amazonian focus. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13071-016-1313-z) contains supplementary material, which is available to authorized users

    Differences in the biometric components of the eye between men and women

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    Objective: To evaluate the differences in ocular biometric components such as axial length (AL), anterior chamber depth (ACD), lens thickness (LT), corneal curvature (CC), and central corneal thickness (CT) between men and women. Methods: Cross-sectional, analytical, and observational study conducted in 106 university with students aged 18-36 years. All subjects underwent refraction under cycloplegia and were assessed through autorefractometry. The refractive error was measured after the application of 1% cyclopentolate. For the identification of biometric components, assessment was performed using the Aladdin equipment (Topcon Corporation, Equipos Oftalmológicos Colombia). Results: A total of 71.7% (76) of the 106 participants included were women aged between 18 and 36 years. The mean AL was 23.3 mm ± 0.88 mm in women and 23.9 mm ± 0.99 mm in men. The ACD was 3.5 mm ± 0.26 mm in women and 3.6 mm ± 0.22 mm in men. LT in women was 3.47 mm ± 0.22 mm and 3.53 mm ± 0.20 mm in men. CT was 538.65 μm ± 0.36 in women and 542.43 μm ± 32.73 in men. The mean keratometry was 43.54D ± 1.35 in women and 42.76D ± 1.79 in men. There were statistically significant differences between CC (−0.78D; p values were 0.01 and 0.03 for men and women, respectively) and AL (0.63 mm; p values were 0.02 and 0.04 for men and women, respectively). Conclusion: There are differences in CC of up to 0.75D that happens to be more curved in women. However, the size of the eyeball is larger in men. These anatomical characteristics are involved in the prevalence of refractive errors

    Crystal Field and Dzyaloshinsky-Moriya Interaction in orbitally ordered La_{0.95}Sr_{0.05}MnO_3: An ESR Study

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    We present a comprehensive analysis of Dzyaloshinsky-Moriya interaction and crystal-field parameters using the angular dependence of the paramagnetic resonance shift and linewidth in single crystals of La_{0.95}Sr_{0.05}MnO_3 within the orthorhombic Jahn-Teller distorted phase. The Dzyaloshinsky-Moriya interaction (~ 1K) results from the tilting of the MnO_6 octahedra against each other. The crystal-field parameters D and E are found to be of comparable magnitude (~ 1K) with D ~= -E. This indicates a strong mixing of the |3z^2-r^2> and |x^2-y^2> states for the real orbital configuration.Comment: 12 pages, 6 figure

    Role of counter-ion and helper lipid content in the design and properties of nanocarrier systems: a biophysical study in 2D and 3D lipid assemblies

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    There is a direct correlation between the physicochemical properties of nanocarrier systems and their biological performance, including stability under physiological conditions, cellular internalization and transfection efficiency. Therefore, understanding the biophysical aspects that affect self-assembled nanocarriers is determinant for a rational design of efficient formulations. In this study, a comprehensive evaluation of the effects of each component on the molecular organization of aggregates formed by the cationic lipids dioctadecyldimethylammonium bromide and chloride (DODAB and DODAC) and the neutral lipid monoolein (MO) was made. Specifically, the effects of the helper lipid content (MO) and the role of the counter-ion of the cationic lipids were evaluated in 2D and 3D assemblies by Langmuir surface pressure–molecular area (π–A) isotherms, Brewster Angle Microscopy (BAM), infrared reflection absorption spectroscopy (IRRAS), confocal Raman microscopy, and Small Angle X-ray Scattering (SAXS). The results show that MO has a different distribution on the DODAC and DODAB bilayers, and a fluidizing effect dependent on the MO content. For low MO molar ratios, the fluidizing effect was more pronounced in DODAC : MO mixtures, indicating a more homogeneous distribution of MO in DODAC than in DODAB bilayers. For high MO molar ratios, packing of membranes was similar for both cationic lipids, and the effect of the counter-ion is attenuated. The distribution of MO in the two cationic systems is closely related with the efficiency of the counter-ions in the screening of the charged group.We acknowledge DAAD/FCT that provided the financial support required to gather the Portuguese and the German coworkers. This work was further supported by FEDER through POFC-COMPETE and by national funds from FCT, through the projects PEst-OE/BIA/UI4050/2014 (CBMA) and PEst-C/FIS/UI0607/2013 (CFUM). Marlene Lúcio acknowledges FCT for the financial support provided by the exploratory project IF/00498/2012. C.R.-A. is grateful to the European Union through the Operational Programme for Cross-border Cooperation: Spain-Portugal under Grant POCTEP 2007-2013 and to European Regional Development Fund for research funding (Innovation in Nanomedicine Project). The authors would also like to acknowledge Irina Berndt and Claudia Botelho

    Reductive Evolution of the Mitochondrial Processing Peptidases of the Unicellular Parasites Trichomonas vaginalis and Giardia intestinalis

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    Mitochondrial processing peptidases are heterodimeric enzymes (α/βMPP) that play an essential role in mitochondrial biogenesis by recognizing and cleaving the targeting presequences of nuclear-encoded mitochondrial proteins. The two subunits are paralogues that probably evolved by duplication of a gene for a monomeric metallopeptidase from the endosymbiotic ancestor of mitochondria. Here, we characterize the MPP-like proteins from two important human parasites that contain highly reduced versions of mitochondria, the mitosomes of Giardia intestinalis and the hydrogenosomes of Trichomonas vaginalis. Our biochemical characterization of recombinant proteins showed that, contrary to a recent report, the Trichomonas processing peptidase functions efficiently as an α/β heterodimer. By contrast, and so far uniquely among eukaryotes, the Giardia processing peptidase functions as a monomer comprising a single βMPP-like catalytic subunit. The structure and surface charge distribution of the Giardia processing peptidase predicted from a 3-D protein model appear to have co-evolved with the properties of Giardia mitosomal targeting sequences, which, unlike classic mitochondrial targeting signals, are typically short and impoverished in positively charged residues. The majority of hydrogenosomal presequences resemble those of mitosomes, but longer, positively charged mitochondrial-type presequences were also identified, consistent with the retention of the Trichomonas αMPP-like subunit. Our computational and experimental/functional analyses reveal that the divergent processing peptidases of Giardia mitosomes and Trichomonas hydrogenosomes evolved from the same ancestral heterodimeric α/βMPP metallopeptidase as did the classic mitochondrial enzyme. The unique monomeric structure of the Giardia enzyme, and the co-evolving properties of the Giardia enzyme and substrate, provide a compelling example of the power of reductive evolution to shape parasite biology

    Acceptability and feasibility of a virtual community of practice to primary care professionals regarding patient empowerment: A qualitative pilot study

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    Background: Virtual communities of practice (vCoPs) facilitate online learning via the exchange of experiences and knowledge between interested participants. Compared to other communities, vCoPs need to overcome technological structures and specific barriers. Our objective was to pilot the acceptability and feasibility of a vCoP aimed at improving the attitudes of primary care professionals to the empowerment of patients with chronic conditions. Methods: We used a qualitative approach based on 2 focus groups: one composed of 6 general practitioners and the other of 6 practice nurses. Discussion guidelines on the topics to be investigated were provided to the moderator. Sessions were audio-recorded and transcribed verbatim. Thematic analysis was performed using the ATLAS-ti software. Results: The available operating systems and browsers and the lack of suitable spaces and time were reported as the main difficulties with the vCoP. The vCoP was perceived to be a flexible learning mode that provided up-to-date resources applicable to routine practice and offered a space for the exchange of experiences and approaches. Conclusions: The results from this pilot study show that the vCoP was considered useful for learning how to empower patients. However, while vCoPs have the potential to facilitate learning and as shown create professional awareness regarding patient empowerment, attention needs to be paid to technological and access issues and the time demands on professionals. We collected relevant inputs to improve the features, content and educational methods to be included in further vCoP implementation. Trial registration: ClinicalTrials.gov, NCT02757781. Registered on 25 April 2016.This study was financed by Instituto de Salud Carlos III and Cofinanced by Fondo Europeo de Desarrollo Regional (FEDER). Ministerio de Economía y Competitividad. Gobierno de España. (PI15/00164, PI15/00586, PI15/00566

    A regulated deficit irrigation strategy for hedgerow olive orchards with high plant density

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    Background & Aims There is not a consensus on the best irrigation approach for super-high density (SHD) olive orchards. Our aim was to design and test a regulated deficit irrigation (RDI) strategy for a sustainable balance between water saving, tree vigour and oil production. Methods We tested our RDI strategy for 3 years in an ‘Arbequina’ orchard with 1,667 trees ha−1. Two levels of irrigation reduction were applied, 60RDI and 30RDI, scaled to replacing 60 % and 30 %, respectively, of the of irrigation needs (IN). We also had a full irrigation (FI) treatment as control, with IN totalling 4,701 m3 ha−1 Results The 30RDI treatment showed the best balance between water saving, tree vigour and oil production. With a yearly irrigation amount (IA) of 1,366 m3 ha−1, which meant 72 % water saving as compared to FI, the reduction in oil yield was 26 % only. Conclusions Our results, together with recent knowledge on the effect of water stress on fruit development, allowed us to suggest a potentially improved RDI strategy for which a total IA of ca. 2,100 m3 ha−1 was calculated. Both some management details and the benefits of this suggested RDI strategy are still to be tested

    Characterization, high-resolution mapping and differential expression of three homologous PAL genes in Coffea canephora Pierre (Rubiaceae)

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    Phenylalanine ammonia lyase (PAL) is the first entry enzyme of the phenylpropanoid pathway producing phenolics, widespread constituents of plant foods and beverages, including chlorogenic acids, polyphenols found at remarkably high levels in the coffee bean and long recognized as powerful antioxidants. To date, whereas PAL is generally encoded by a small gene family, only one gene has been characterized in Coffea canephora (CcPAL1), an economically important species of cultivated coffee. In this study, a molecular- and bioinformatic-based search for CcPAL1 paralogues resulted successfully in identifying two additional genes, CcPAL2 and CcPAL3, presenting similar genomic structures and encoding proteins with close sequences. Genetic mapping helped position each gene in three different coffee linkage groups, CcPAL2 in particular, located in a coffee genome linkage group (F) which is syntenic to a region of Tomato Chromosome 9 containing a PAL gene. These results, combined with a phylogenetic study, strongly suggest that CcPAL2 may be the ancestral gene of C. canephora. A quantitative gene expression analysis was also conducted in coffee tissues, showing that all genes are transcriptionally active, but they present distinct expression levels and patterns. We discovered that CcPAL2 transcripts appeared predominantly in flower, fruit pericarp and vegetative/lignifying tissues like roots and branches, whereas CcPAL1 and CcPAL3 were highly expressed in immature fruit. This is the first comprehensive study dedicated to PAL gene family characterization in coffee, allowing us to advance functional studies which are indispensable to learning to decipher what role this family plays in channeling the metabolism of coffee phenylpropanoids
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