1,455 research outputs found

    Microbial Activity Response to Solar Radiation across Contrasting Environmental Conditions in Salar de Huasco, Northern Chilean Altiplano

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    Indexación: Web of Science; Scopus.In high altitude environments, extreme levels of solar radiation and important differences of ionic concentrations over narrow spatial scales may modulate microbial activity. In Salar de Huasco, a high-altitude wetland in the Andean mountains, the high diversity of microbial communities has been characterized and associated with strong environmental variability. Communities that differed in light history and environmental conditions, such as nutrient concentrations and salinity from different spatial locations, were assessed for bacterial secondary production (BSP, H-3-leucine incorporation) response from short-term exposures to solar radiation. We sampled during austral spring seven stations categorized as: (a) source stations, with recently emerged groundwater (no-previous solar exposure); (b) stream running water stations; (c) stations connected to source waters but far downstream from source points; and (d) isolated ponds disconnected from ground sources or streams with a longer isolation and solar exposure history. Very high values of 0.25 mu E m(-2) s(-1), 72 W m(-2) and 12 W m(-2) were measured for PAR, UVA, and UVB incident solar radiation, respectively. The environmental factors measured formed two groups of stations reflected by principal component analyses (near to groundwater sources and isolated systems) where isolated ponds had the highest BSP and microbial abundance (35 microalgae taxa, picoeukaryotes, nanoflagellates, and bacteria) plus higher salinities and PO43- concentrations. BSP short-term response (4 h) to solar radiation was measured by H-3-leucine incorporation under four different solar conditions: full sun, no UVB, PAR, and dark. Microbial communities established in waters with the longest surface exposure (e.g., isolated ponds) had the lowest BSP response to solar radiation treatments, and thus were likely best adapted to solar radiation exposure contrary to ground source waters. These results support our light history (solar exposure) hypothesis where the more isolated the community is from ground water sources, the better adapted it is to solar radiation. We suggest that factors other than solar radiation (e.g., salinity, PO43-, NO3-) are also important in determining microbial productivity in heterogeneous environments such as the Salar de Huasco.http://journal.frontiersin.org/article/10.3389/fmicb.2016.01857/ful

    Two cold inducible genes encoding lipid transfer protein LTP4 from barley show differential responses to bacterial pathogens

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    The barley genesHvLtp4.2 andHvLtp4.3 both encode the lipid transfer protein LTP4 and are less than 1 kb apart in tail-to-tail orientation. They differ in their non-coding regions from each other and from the gene corresponding to a previously reportedLtp4 cDNA (nowLtp4.1). Southern blot analysis indicated the existence of three or moreLtp4 genes per haploid genome and showed considerable polymorphism among barley cultivars. We have investigated the transient expression of genesHvLtp4.2 andHvLtp4.3 following transformation by particle bombardment, using promoter fusions to the-glucuronidase reporter sequence. In leaves, activities of the two promoters were of the same order as those of the sucrose synthase (Ss1) and cauliflower mosaic virus 35S promoters used as controls. Their expression patterns were similar, except thatLtp4.2 was more active thanLtp4.3 in endosperm, andLtp4.3 was active in roots, whileLtp4.2 was not. The promoters of both genes were induced by low temperature, both in winter and spring barley cultivars. Northern blot analysis, using theLtp4-specific probe, indicated thatXanthomonas campestris pv.translucens induced an increase over basal levels ofLtp4 mRNA, whilePseudomonas syringae pv.japonica caused a decrease. TheLtp4.3-Gus promoter fusion also responded in opposite ways to these two compatible bacterial pathogens, whereas theLtp4.2-Gus construction did not respond to infectio

    Rescate de patashte (Theobroma bicolor Humb & Bonpl.) y cushta (Theobroma angustifolium) dos especies promisorias en peligro de extinción en El Salvador

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    En El Salvador existen especies vegetales como el patashte (Theobroma bicolor) y la cushta (Theobroma angustifolium) parientes silvestres del cacao, con alto potencial nutritivo para la alimentación y como materia prima para la agroindustria y el desarrollo de productos como chocolate, atoles, snack, entre otros, no obstante, estas especies están en peligro de extinción, por lo que no se cuenta con mucha información técnica. Por tal motivo se realizaron giras de colecta de estas especies, en municipios, con tradición en la producción de cacao a fin de incluir ambas especies en los bancos de germoplasma de cacao que se establecieron como parte del proyecto de rescate de recursos genéticos de cacao. Sin embargo, la situación de ambas especies es crítica por el alto grado de erosión genética, ya que, solamente se lograron obtener muestras de frutos en el cantón Cangrejera, Izalco, Sonsonate. Estas muestras se llevaron al Laboratorio de Química Agrícola de la Facultad de Ciencias Agronómicas de La Universidad de El Salvador (UES), a fin de realizar análisis bromatológicos y conocer de manera preliminar su composición química. Asimismo, desarrollar viveros con ambas especies para siembra en las colecciones de la UES. Como resultado se encontraron concentraciones para patashte y cushta de 16.04 y 4.48% de proteína; de 33.81 y 23.93% de grasa; 35.02 y 44.75% de carbohidratos respectivamente. Por otra parte se establecieron plantas de patashte y cushta en el banco de germoplasma del campus universitario, Estación Experimental y de Prácticas (EEP), San Pedro Nonualco y La cooperativa Hacienda Santa Clara, procurando contribuir al rescate de las mismas. Se concluye que ambas especies tienen potencial para consumo directo con preparaciones artesanales y materia prima para elaboración de muchos productos alimenticios nutritivos, e incluirlos en programas de Seguridad Alimentaria y Nutricional (SAN), por lo que es importante y urgente, proponer y ejecutar estrategias de conservación in situ y ex situ

    Use of mixed methods designs in substance research: a methodological necessity in Nigeria

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    The utility of mixed methods (qualitative and quantitative) is becoming increasingly accepted in health sciences, but substance studies are yet to substantially benefit from such utilities. While there is a growing number of mixed methods alcohol articles concerning developed countries, developing nations are yet to embrace this method. In the Nigerian context, the importance of mixed methods research is yet to be acknowledged. This article therefore, draws on alcohol studies to argue that mixed methods designs will better equip scholars to understand, explore, describe and explain why alcohol consumption and its related problems are increasing in Nigeria. It argues that as motives for consuming alcohol in contemporary Nigeria are multiple, complex and evolving, mixed method approaches that provide multiple pathways for proffering solutions to problems should be embraced

    Effects of food on physical and sleep complaints in children with ADHD: a randomised controlled pilot study

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    Attention deficit/hyperactivity disorder (ADHD), a common behavioural disorder in children, may be associated with comorbid physical and sleep complaints. Dietary intervention studies have shown convincing evidence of efficacy in reducing ADHD symptoms in children. In this pilot study, we investigated the effects of an elimination diet on physical and sleep complaints in children with ADHD. A group of 27 children (3.8–8.5 years old), who all met the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for ADHD, were assigned randomly to either a diet group (15/27) or a control group (12/27). The diet group followed a 5-week elimination diet; the control group adhered to their normal diet. Parents of both groups had to keep an extended diary and had to monitor the behaviour and the physical and sleep complaints of their child conscientiously. The primary endpoint was the clinical response, i.e. a decrease of physical and sleep complaints, at the end of the trial, based on parent ratings on a Physical Complaints Questionnaire. The number of physical and sleep complaints was significantly decreased in the diet group compared to the control group (p < 0.001), with a reduction in the diet group of 77% (p < 0.001, effect size = 2.0) and in the control group of 17% (p = 0.08, effect size = 0.2). Specific complaints that were significantly reduced were in three domains: headaches or bellyaches, unusual thirst or unusual perspiration, and sleep complaints. The reduction of complaints seemed to occur independently of the behavioural changes (p = 0.1). However, the power of this comparison was low. A positive correlation existed between the reduction of physical and behavioural symptoms (p < 0.01). The reduction did not differ between children with or without an atopic constitution (p = 0.7). An elimination diet may be an effective instrument to reduce physical complaints in children with ADHD, but more research is needed to determine the effects of food on (functional) somatic symptoms in children with and without ADHD. This trial was registered as an International Standard Randomised Controlled Trial, ISRCTN47247160

    Modified carbon fabric electrodes: preparation and electrochemical behavior toward amaranth electrolysis

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    The final publication is available at Springer via http://dx.doi.org/10.1007/s10800-014-0769-9The electrochemical behavior of non-modified, Pt-modified, and Pt/polyaniline-modified carbon fiber textile electrodes was studied through a series of electrolyses, under potentiostatic conditions, on an amaranth/sulfuric solution in the presence or absence of chloride ion. The morphology of the dispersed Pt, PANI, and PANI/Pt coatings was analyzed by scanning electron microscopy. Scanning electrochemical microscopy confirmed that the textile surface was effectively modified by the electrocatalytic material. Color removal reached values above 90 % in both electroreduction and electrooxidation processes. The amaranth electroreductions carried out with the non-modified electrode showed better charge efficiency than those with the Pt-modified textile electrode. The electrooxidations with Pt-modified textile electrodes showed a significant reduction in electrolysis time. Ultraviolet-visible and Fourier transform infrared with attenuated total reflection spectra enabled the electrochemical behavior of the non-modified and Pt/PANI-modified electrodes to be distinguished.The authors wish to acknowledge to the Spanish Ministerio de Ciencia e Innovacion (contract CTM2011-23583) and Universitat Politecnica de Valencia (Vicerrectorado de Investigacion PAID-06-10 contract 003-233) for the financial support; and as well as Carbongen S. A. (Cocentaina, Spain), who kindly donated the activated carbon fabric. J. Molina is grateful to the Conselleria d'Educacio, Formacio i Ocupacio (Generalitat Valenciana) for the Programa VALi+D Postdoctoral Fellowship. A.I. del Rio is grateful to the Spanish Ministerio de Ciencia y Tecnologia for the FPI fellowship.Fernández Sáez, J.; Del Río García, AI.; Molina Puerto, J.; Bonastre Cano, JA.; Cases Iborra, FJ. (2015). Modified carbon fabric electrodes: preparation and electrochemical behavior toward amaranth electrolysis. Journal of Applied Electrochemistry. 45(3):263-272. https://doi.org/10.1007/s10800-014-0769-9S263272453Marsh H, Reinoso FR (2000) Sciences of carbon materials. Universidad de Alicante, AlicanteKinoshita K (1998) Carbon: electrochemical and physicochemical properties. Wiley, New York, pp 293–387Burchell TD (1999) Carbon materials for advances technologies. Pergamon, AmsterdamDomínguez SD, Pardilla JA, Murcia AB, Morallón E, Amorós DC (2008) Electrochemical deposition of Pt nanoparticles on different carbon supports and conducting polymers. J Appl Electrochem 38:259–268Kezhong W, Xu M, Xindong W, Jingling L (2005) Pt–Polyaniline-modified carbon fiber electrode for the electrooxidation of methanol. Rare Met 24:33–36Wu G, Li L, Li JH, Xu BQ (2006) Methanol electrooxidation on Pt particles dispersed into PANI/SWNT composite films. J Power Sources 155:118–127Singh RN, Awasthi R, Tiwari SK (2010) Electro-catalytic activities of binary nano-composites of Pt and nano-carbon/multiwall carbon nanotube for methanol electro-electrooxidation. Open Catal J 3:50–57Zhiani M, Rezaei B, Jalili J (2010) Methanol electro-electrooxidation on Pt/C modified by polyaniline nanofibers for DMFC applications. Int J Hydrogen Energ 35:9298–9305Laborde H, Léger J-M, Lamy C (1994) Electrocatalytic electrooxidation of methanol and C1 molecules on highly dispersed electrodes. Part 1: Pt in polyaniline. J Appl Electrochem 24:219–226Niu L, Li Q, Wei F, Wu S, Liu P, Cao X (2005) Electrocatalytic behaviour of Pt-modified polyaniline electrode for methanol electrooxidation: effect of Pt deposition modes. J Electroanal Chem 578:331–337Huang LM, Tang WR, Wen TCh (2007) Spatially electrodeposited Pt in polyaniline doped with poly(styrene sulfonic acid) for methanol electrooxidation. J Power Sources 164:519–526Fernández J, Molina J, del Río AI, Bonastre J, Cases FJ (2012) Synthesis and characterization of electrochemically platinum–polyaniline modified carbon textile electrodes. Int J Electrochem Sci 7:10175–10189Snehalatha M, Ravikumar C, Sekar N, Jayakumar SV, Joe H (2008) FT–Raman, IR and UV–visible spectral investigations and ab initio computations of a nonlinear food dye amaranth. J Raman Spectrosc 39:928–936Rajendran L, Ananthi SP (2004) Analysis of positive feedback currents at the scanning electrochemical microscope. J Electroanal Chem 561:113–118Niu L, Li Q, Wei F, Chen X, Wang W (2003) Formation optimization of Pt-modified polyaniline films for the electrocatalytic electrooxidation of methanol. Synthetic Met 139:271–276Sala M, del Río AI, Molina J, Cases F, Gutierrez-Bouzán MC (2012) Influence of cell design and electrode materials on the decoloration of dyeing effluents. 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    Applying refinement to the use of mice and rats in rheumatoid arthritis research

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    Rheumatoid arthritis (RA) is a painful, chronic disorder and there is currently an unmet need for effective therapies that will benefit a wide range of patients. The research and development process for therapies and treatments currently involves in vivo studies, which have the potential to cause discomfort, pain or distress. This Working Group report focuses on identifying causes of suffering within commonly used mouse and rat ‘models’ of RA, describing practical refinements to help reduce suffering and improve welfare without compromising the scientific objectives. The report also discusses other, relevant topics including identifying and minimising sources of variation within in vivo RA studies, the potential to provide pain relief including analgesia, welfare assessment, humane endpoints, reporting standards and the potential to replace animals in RA research

    Multiple sclerosis drug FTY-720 toxicity is mediated by the heterotypic fusion of organelles in neuroendocrine cells

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    FTY-720 (Fingolimod) was one of the first compounds authorized for the treatment of multiple sclerosis. Among its other activities, this sphingosine analogue enhances exocytosis in neuroendocrine chromaffin cells, altering the quantal release of catecholamines. Surprisingly, the size of chromaffin granules is reduced within few minutes of treatment, a process that is paralleled by the homotypic fusion of granules and their heterotypic fusion with mitochondria, as witnessed by dynamic confocal and TIRF microscopy. Electron microscopy studies support these observations, revealing the fusion of several vesicles with individual mitochondria to form large, round mixed organelles. This cross-fusion is SNARE-dependent, being partially prevented by the expression of an inactive form of SNAP-25. Fused mitochondria exhibit an altered redox potential, which dramatically enhances cell death. Therefore, the cross-fusion of intracellular organelles appears to be a new mechanism to be borne in mind when considering the effect of FTY-720 on the survival of neuroendocrine cells

    Contribution of cell blocks obtained through endobronchial ultrasound-guided transbronchial needle aspiration to the diagnosis of lung cancer

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    <p>Abstract</p> <p>Background</p> <p>Conventional smears of samples obtained by endobronchial ultrasound with real-time transbronchial needle aspiration (EBUS-TBNA) have proven useful in lung cancer staging, but the value of additional information from cell-block processing of EBUS-TBNA samples has only been marginally investigated. This study focussed on the contribution of cell block analysis to the diagnostic yield in lung cancer.</p> <p>Methods</p> <p>Patients referred for lung cancer diagnosis and/or staging by means of EBUS-TBNA were enrolled, the adequacy of the obtained samples for preparing cell blocks was assessed, and the additional pathologic or genetic information provided from cell block analysis was examined.</p> <p>Results</p> <p>In 270 lung cancer patients referred for EBUS-TBNA (mean age, 63.3 SD 10.4 years) 697 aspirations were performed. Cell blocks could be obtained from 334 aspirates (47.9%) and contained diagnostic material in 262 (37.6%) aspirates, providing information that was additional to conventional smears in 50 of the 189 samples with smears that were non-diagnostic, corresponding 21 of these blocks to malignant nodes, and allowing lung cancer subtyping of 4 samples. Overall, cell blocks improved the pathologic diagnosis attained with conventional smears in 54 of the 697 samples obtained with EBUS-TBNA (7.7%). Cell blocks obtained during EBUS-TBNA also made epithelial growth factor receptor mutation analysis possible in 39 of the 64 patients with TBNA samples showing metastatic adenocarcinoma (60.1%). Overall, cell blocks provided clinically significant information for 83 of the 270 patients participating in the study (30.7%).</p> <p>Conclusions</p> <p>Cell-block preparation from EBUS-TBNA samples is a simple way to provide additional information in lung cancer diagnosis. Analysis of cell blocks increases the diagnostic yield of the procedure by nearly seven per cent and allows for genetic analysis in a sixty per cent of the patients with metastatic adenocarcinoma.</p
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