1,112 research outputs found

    Three-dimensional flow structure and bed morphology in large elongate meander loops with different outer bank roughness characteristics

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    © 2016. American Geophysical Union. All Rights Reserved. Few studies have examined the three-dimensional flow structure and bed morphology within elongate loops of large meandering channels. The present study focuses on the spatial patterns of three-dimensional flow structure and bed morphology within two elongate meander loops and examines how differences in outer bank roughness influence near-bank flow characteristics. Three-dimensional velocities were measured during two different events—a near-bankfull flow and an overbank event. Detailed data on channel bathymetry and bed form geometry were obtained during a near-bankfull event. Flow structure within the loops is characterized by strong topographic steering by the point bar, by the development of helical motion associated with flow curvature, and by acceleration of flow where bedrock is exposed along the outer bank. Near-bank velocities during the overbank event are less than those for the near-bankfull flow, highlighting the strong influence of the point bar on redistribution of mass and momentum of the flow at subbankfull stages. Multiple outer bank pools are evident within the elongate meander loop with low outer bank roughness, but are not present in the loop with high outer bank roughness, which may reflect the influence of abundant large woody debris on near-bank velocity characteristics. The positions of pools within both loops can be linked to spatial variations in planform curvature. The findings indicate that flow structure and bed morphology in these large elongate loops is similar to that in small elongate loops, but differs somewhat from flow structure and bed morphology reported for experimental elongate loops

    Effect of Shear on Performance and Microbial Ecology of Continuously Stirred Anaerobic Digesters Treating Animal Manure

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    We Determined the Effect of Different Mixing Intensities on the Performance, Methanogenic Population Dynamics, and Juxtaposition of Syntrophic Microbes in Anaerobic Digesters Treating Cow Manure from a Dairy Farm. Computer Automated Radioactive Particle Tracking in Conjunction with Computational Fluid Dynamics Was Performed to Quantify the Shear Levels Locally. Four Continuously Stirred Anaerobic Digesters Were Operated at Different Mixing Intensities of 1,500, 500, 250, and 50 Revolutions Per Min (RPM) over a 260-Day Period at a Temperature of 34 ± 1°C. Animal Manure at a Volatile Solids (VS) Concentration of 50 G/L Was Fed into the Digesters Daily at Five Different Organic Loading Rates between 0.6 and 3.5 G vs./L Day. the Different Mixing Intensities Had No Effect on the Biogas Production Rates and Yields at Steady-State Conditions. a Methane Yield of 0.241 ± 0.007 L CH 4/g vs. Fed Was Obtained by Pooling the Data of All Four Digesters during Steady-State Periods. However, Digester Performance Was Affected Negatively by Mixing Intensity during Startup of the Digesters, with Lower Biogas Production Rates and Higher Volatile Fatty Acids Concentrations Observed for the 1,500-RPM Digester. Despite Similar Methane Production Yields and Rates, the Acetoclastic Methanogenic Populations Were Different for the High- and Low-Intensity Mixed Digesters with Methanosarcina Spp. and Methanosaeta Concilii as the Predominant Methanogens, Respectively. for All Four Digesters, Epifluorescence Microscopy Revealed Decreasing Microbial Floc Sizes Beginning at Week 4 and Continuing through Week 26 after Which No Microbial Flocs Remained. This Decrease in Size, and Subsequent Loss of Microbial Flocs Did Not, However, Produce Any Long-Term Upsets in Digester Performance. © 2007 Wiley Periodicals, Inc

    Use of Limpograss as an Alternative Feed During the Fall Forage Gap in Beef and Dairy Systems in Central and North Florida

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    In central and North Florida, the use of limpograss [Hemarthria altissima (Poir.) Stapf & C. E. Hubb.] for beef and dairy operations is limited and its potential use is not well documented. Two on-farm projects have been conducted in Central and North Florida to explore the use of limpograss as an alternative conserved forage during late fall and winter. The potential use of this forage as baleage for dairy farmers and as stockpiling for livestock producers would offer another alternative to reduce feed costs and fill the forage gap in the area when typical warm-season forages go dormant. In addition, the on-farm limpograss establishment would serve as dissemination for the limpograss planting material. Four dairy farms in Central and North Florida were enrolled in the study to evaluate two cultivars of limpograss for their potential when conserved as baleage. Four 0.2 ha strips were planted per farm, two for each variety (‘Kenhy’ and ‘Gibtuck’). The strips were arranged in a randomized complete block design, with two replicates in each location. Before wrapping the harvested forage for baleage, samples were taken to evaluate crude protein (CP) and in vitro digestible organic matter concentration (IVDOM). In addition, samples of fresh baleage at 60 and 90 d were analyzed for fermentation profile (pH, organic acids, and ammonia). Four beef cattle farms in North Florida allowed us to plant 1 ha of ‘Gibtuck’ for stockpiling evaluating the nutritive value at 30, 60, 90, and 120 days. Each plot was replicated four times and allocated in a randomized complete block design. The fermentation profile from the bales does not show differences between cultivars (P \u3e 0.05) and the pH is lower than 5 indicating that the fermentation process was successful. The CP and IVDOM of the stockpiling limpograss were different among the treatments (P \u3c 0.001)

    Primeiro registro de um raro peixe parasita Pseudostegophilus paulensis no rio Paranapanema e sua distribuição atual no Brasil

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    Pseudostegophilus paulensis Miranda Ribeiro 1918 is an endemic parasitic species from the state of São Paulo, southeastern Brazil, with few registered occurrences in databases (15 records). Here, we present the first record of P. paulensis in the middle portion of the Anhumas River, a tributary of the Paranapanema River right bank. Specimens were collected in two environments with different ecological characteristics (lotic water running over gravel sediment and semi-lotic water with silty sediment on the bottom). We also present an updated occurrence map of the species in Brazil. This new record of P. paulensis in the upper Paraná River basin extends the geographic distribution of the species to the South of the state of São Paulo.  Furthermore, important ecological information remains unknown due to the lack of data about this group, such as habitat niches, vertical migration, growth patterns, reproduction, and feeding behavior.Pseudostegophilus paulensis Miranda Ribeiro 1918 é uma espécie de peixe parasita endêmica do estado de São Paulo, sudeste do Brasil, com poucas ocorrências registradas em bancos de dados (15 registros). Aqui, apresentamos o primeiro registro de P. paulensis na porção média do rio Anhumas, afluente da margem direita do rio Paranapanema. Os espécimes foram coletados em dois ambientes com características ecológicas distintas (água lótica correndo sobre sedimento pedregulho e água semilótica com sedimento arenoso no fundo). Apresentamos também um mapa de ocorrência atualizado da espécie no Brasil. Este novo registro de P. paulensis na bacia do alto rio Paraná estende a distribuição geográfica da espécie para o sul do estado de São Paulo. Além disso, informações ecológicas importantes permanecem desconhecidas devido à falta de dados sobre esse grupo, como nichos de habitat, migração vertical, padrões de crescimento, reprodução e comportamento alimentar

    Shape Tailored Magnetic Nanorings for Intracellular Hyperthermia Cancer Therapy

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    This work explores a new class of vortex/magnetite/iron oxide nanoparticles designed for magnetic hyperthermia applications. These nanoparticles, named Vortex Iron oxide Particles (VIPs), are an alternative to the traditional Superparamagnetic Iron Oxide Nanoparticles (SPIONs), since VIPs present superior heating power while fulfilling the main requirements for biomedical applications (low cytotoxicity and nonremanent state). In addition, the present work demonstrates that the synthesized VIPs also promote an internalization and aggregation of the particles inside the cell, resulting in a highly localized hyperthermia in the presence of an alternating magnetic field. Thereby, we demonstrate a new and efficient magnetic hyperthermia strategy in which a small, but well localized, concentration of VIPs can promote an intracellular hyperthermia process

    Sliding Mode Control for Active Suspension System with Data Acquisition Delay

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    This paper addresses the problem of control of an active suspension system accomplished using a computer. Delay in the states due to the acquisition and transmission of data from sensors to the controller is taken into account. The proposed control strategy uses state predictors along with sliding mode control technique. Two approaches are made: a continuous-time and a discrete-time control. The proposed designs, continuous-time and discrete-time, are applied to the active suspension module simulator from Quanser. Results from computer simulations and experimental tests are analyzed to show the effectiveness of the proposed control strategy

    Benznidazole in cerebrospinal fluid: A case series of chagas disease meningoencephalitis in hiv-positive patients

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    Chagas disease reactivation in HIV-positive people is an opportunistic infection with 79 to 100% mortality. It commonly involves the central nervous system (CNS). Early treatment with trypanocidal drugs such as benznidazole (BNZ) is crucial for this severe manifestation of Trypanosoma cruzi infection. However, limited BNZ clinical pharmacology data are available, especially its concentration in the CNS. We report a series of HIV-positive patients undergoing treatment for T. cruzi meningoencephalitis, their clinical response, and cerebrospinal fluid (CSF) and plasma BNZ concentrations. Measurements were carried out using leftover samples originally obtained for routine medical care. A high-performance liquid chromatography/tandem mass spectrometry bioanalytical method designed for BNZ plasma measurements was adapted and validated for CSF samples. Six patients were enrolled in this study from 2015 to 2019. A total of 6 CSF and 19 plasma samples were obtained. Only three of the CSF samples had detectable BNZ levels, all under 1mg/ml. Fifteen plasma samples had detectable BNZ, and 13 were above 2mg/ml, which is the putative trypanocidal level. We observed BNZ concentrations in human CSF and plasma. CSF BNZ concentrations were low or not measurable in all patients, suggesting that the usual BNZ doses may be suboptimal in HIV-positive patients with T. cruzi meningoencephalitis. While drug-drug and drug-disease interactions may be in part responsible, the factors leading to low CSF BNZ levels remain to be studied in detail. These findings highlight the potential of therapeutic drug monitoring in BNZ treatment and suggest that the use of higher doses may be useful for Chagas disease CNS reactivations

    Music and HCI

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    Music is an evolutionarily deep-rooted, abstract, real-time, complex, non-verbal, social activity. Consequently, interaction design in music can be a valuable source of challenges and new ideas for HCI. This workshop will reflect on the latest research in Music and HCI (Music Interaction for short), with the aim of strengthening the dialogue between the Music Interaction community and the wider HCI community. We will explore recent ideas from Music Interaction that may contribute new perspectives to general HCI practice, and conversely, recent HCI research in non-musical domains with implications for Music Interaction. We will also identify any concerns of Music Interaction that may require unique approaches. Contributors engaged in research in any area of Music Interaction or HCI who would like to contribute to a sustained widening of the dialogue between the distinctive concerns of the Music Interaction community and the wider HCI community will be welcome

    Viruses that affect Argentinian honey bees (Apis mellifera)

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    Beekeeping is a widespread activity in Argentina, mainly producing honey that has gained both national and international recognition. There are more than 3,000,000 hives in the country, mainly concentrated in Buenos Aires Province (approximately 1,000,000 hives). In recent decades, worrying rates of hive loss have been observed in many countries around the world. In Latin America, the estimated loss of hives is between 13% (Peru and Ecuador) and 53% (Chile). Argentina had annual losses of 34% for the period of October 1, 2016 to October 1, 2017. The causes of these losses are not clear but probably involve multiple stressors that can act simultaneously. One of the main causes of loss of bee colonies worldwide is infestation by the ectoparasitic mite Varroa destructor in combination with viral infections. To date, 10 viruses have been detected that affect honey bees (Apis mellifera) in Argentina. Of these, deformed wing virus, sacbrood virus, acute bee paralysis virus, chronic bee paralysis virus, and Israeli acute bee paralysis can be transmitted by mites. Deformed wing virus and the AIK complex are the viruses most often associated with loss of hives worldwide. Considering that bee viruses have been detected in Argentina in several hymenopteran and non-hymenopteran insects, these hosts could act as important natural reservoirs for viruses and play an important role in their dispersal in the environment. Further studies to investigate the different mechanisms by which viruses spread in the environment will enable us to develop various strategies for the control of infected colonies and the spread of viruses in the habitat where they are found.Fil: Salina, Marcos Daniel. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina. Ministerio de Ciencia. Tecnología e Innovación Productiva. Agencia Nacional de Promoción Científica y Tecnológica; ArgentinaFil: Genchi Garcia, María L.. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Bais, Bárbara Belén. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Bravi, Maria Emilia. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Brasesco, Maria Constanza. Universidad Nacional de Mar del Plata. Instituto de Investigaciones en Producción, Sanidad y Ambiente - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Producción, Sanidad y Ambiente; ArgentinaFil: Maggi, Matías Daniel. Universidad Nacional de Mar del Plata. Instituto de Investigaciones en Producción, Sanidad y Ambiente - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Producción, Sanidad y Ambiente; ArgentinaFil: Pecoraro, Marcelo Ricardo. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Larsen, Alejandra Edith. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Sguazza, Guillermo Hernán. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Reynaldi, Francisco José. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentin
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