354 research outputs found
Multicolor 3D Orbital Tracking
Feedback-based single-particle tracking (SPT) is a powerful technique for investigating particle behavior with very high spatiotemporal resolution. The ability to follow different species and their interactions independently adds a new dimension to the information available from SPT. However, only a few approaches have been expanded to multiple colors and no method is currently available that can follow two differently labeled biomolecules in 4 dimensions independently. In this proof-of-concept paper, the new modalities available when performing 3D orbital tracking with a second detection channel are demonstrated. First, dual-color tracking experiments are described studying independently diffusing particles of different types. For interacting particles where their motion is correlated, a second modality is implemented where a particle is tracked in one channel and the position of the second fluorescence species is monitored in the other channel. As a third modality, 3D orbital tracking is performed in one channel while monitoring its spectral signature in a second channel. This last modality is used to successfully readout accurate Forster Resonance Energy Transfer (FRET) values over time while tracking a mobile particle
MetalâOrganic Framework Nanoparticles Induce Pyroptosis in Cells Controlled by the Extracellular pH
Ion homeostasis is essential for cellular survival, and elevated concentrations of specific ions are used to start distinct forms of programmed cell death. However, investigating the influence of certain ions on cells in a controlled way has been hampered due to the tight regulation of ion import by cells. Here, it is shown that lipidâcoated ironâbased metalâorganic framework nanoparticles are able to deliver and release high amounts of iron ions into cells. While high concentrations of iron often trigger ferroptosis, here, the released iron induces pyroptosis, a form of cell death involving the immune system. The iron release occurs only in slightly acidic extracellular environments restricting cell death to cells in acidic microenvironments and allowing for external control. The release mechanism is based on endocytosis facilitated by the lipidâcoating followed by degradation of the nanoparticle in the lysosome via cysteineâmediated reduction, which is enhanced in slightly acidic extracellular environment. Thus, a new functionality of hybrid nanoparticles is demonstrated, which uses their nanoarchitecture to facilitate controlled ion delivery into cells. Based on the selectivity for acidic microenvironments, the described nanoparticles may also be used for immunotherapy: the nanoparticles may directly affect the primary tumor and the induced pyroptosis activates the immune system
A study of wrist-worn activity measurement as a potential real-world biomarker for late-life depression.
BACKGROUND: Late-life depression (LLD) is associated with a decline in physical activity. Typically this is assessed by self-report questionnaires and, more recently, with actigraphy. We sought to explore the utility of a bespoke activity monitor to characterize activity profiles in LLD more precisely. METHOD: The activity monitor was worn for 7 days by 29 adults with LLD and 30 healthy controls. Subjects underwent neuropsychological assessment and quality of life (QoL) (36-item Short-Form Health Survey) and activities of daily living (ADL) scales (Instrumental Activities of Daily Living Scale) were administered. RESULTS: Physical activity was significantly reduced in LLD compared with controls (t = 3.63, p < 0.001), primarily in the morning. LLD subjects showed slower fine motor movements (t = 3.49, p < 0.001). In LLD patients, activity reductions were related to reduced ADL (r = 0.61, p < 0.001), lower QoL (r = 0.65, p < 0.001), associative learning (r = 0.40, p = 0.036), and higher Montgomery-Ă
sberg Depression Rating Scale score (r = -0.37, p < 0.05). CONCLUSIONS: Patients with LLD had a significant reduction in general physical activity compared with healthy controls. Assessment of specific activity parameters further revealed the correlates of impairments associated with LLD. Our study suggests that novel wearable technology has the potential to provide an objective way of monitoring real-world function.This study was funded by an award from the UK
Medical Research Council (G1001828/1)
InfluĂȘncia de prĂĄticas culturais e da resistĂȘncia genĂ©tica na intensidade do cancro da haste e produção de soja no Cerrado
Os efeitos de prĂĄticas culturais e resistĂȘncia genĂ©tica na intensidade ao cancro-da-haste da soja (Diaporthe phaseolorum f.sp. meridionalis - Dpm) foram examinados na safra 1995-96 em ĂĄreas de produção comercial, que haviam sido severamente atacadas na safra anterior (1994-95). Um experimento investigou os efeitos de cultivo mĂnimo (MT) e do plantio direto (NT) no desenvolvimento da doença e produtividade das cultivares FT-Cristalina e FT-Seriema. Em outro experimento, semeado em plantio direto, estudou-se o efeito da densidade de plantas (8, 15, 21 e 36 plantas/m) no desenvolvimento da doença e produtividade das cvs. FT-Cristalina (suscetivel), FT- 101 (moderadamente resistente) e FT-104 (resistente). IncidĂȘncia e severidade da doença foram menores em NT do que em MT. A produtividade aumentou no sistema NT (23% para âFT-Cristalinaâ e 14% para âFT-Seriemaâ), comparada com as produtividades em MT. As curvas de progresso da doença foram melhor descritas pelos mo- delos de Gompertz e logĂstico. A severidade do cancro aumentou pro- porcionalmente ao aumento das densidades de plantio nas cvs. suscetĂvel e moderadamente resistente. No final do ciclo, 100% das plantas da cv. FT-Cristalina estavam infetadas por Dpm, em todas as densidades de plantio. NĂveis intermediĂĄrios de doença foram observa- dos na cv. FT-101, enquanto apenas nĂveis muito baixos de doença ocorreram na cv. FT-104. Estabeleceu-se uma correlação negativa entre severidade de cancro-da-haste e produção. Algumas das prĂĄticas estudadas demonstraram potential para aplicação direta no controle da doença, e poderiam ser combinadas considerando-se seus efeitos aditivos.Field experiments were conducted in the 1995-96 soybean (Glycine max) growing season to evaluate the effects of cultural practices and host genetic resistance on the intensity of soybean stem canker, caused by Diaporthe phaseolorum f.sp. meridionalis (Dpm). Experiments were conducted in a commercial field severely infected in the previous (1994-95) season. In one study, minimum tillage (MT) and no-tillage (NT) cropping systems were investigated for their effects on disease development and on plant yields in cvs. FT- Cristalina (susceptible) and FT-Seriema (moderately resistant). Another study evaluated the effects of plant densities (8, 15, 21 and 36 plants/m) on disease development in cvs. FT-Cristalina, FT-101 (moderately resistant) and FT-104 (resistant). Disease incidence and severity were consistently lower in NT than in MT, and plant yields were increased by 23% and 14% in the NT system for the susceptible and moderately resistant cultivars, respectively, compared to the yields in the MT system. The Gompertz and Logistic models described well the disease progress curves in all situations. For both susceptible and moderately resistant cultivars, disease severity increased proportionately to the increase in plant densities. At the end of the season, 100% of the plants of cv. FT-Cristalina were infected by Dpm, at all plant densities. Disease levels on cv. FT-101 were intermediate while only very low disease levels were recorded on cv. FT-104. There was a consistent negative correlation between stem canker severity and yield. Some practices demonstrated potential for direct application in disease control, and could be combined considering their additive effects
The TANAMI Program
TANAMI (Tracking Active Galactic Nuclei with Austral Milliarcsecond
Interferometry) is a monitoring program to study the parsec-scale structures
and dynamics of relativistic jets in active galactic nuclei (AGN) of the
Southern Hemisphere with the Long Baseline Array and associated telescopes.
Extragalactic jets south of -30 degrees declination are observed at 8.4 GHz and
22 GHz every two months at milliarcsecond resolution. The initial TANAMI sample
is a hybrid radio and gamma-ray selected sample since the combination of VLBI
and gamma-ray observations is crucial to understand the broadband emission
characteristics of AGN.Comment: Confernce Proceedings for "X-ray Astronomy 2009" (Bologna), 3 pages,
3 figures, needs cls-fil
Current status of the taxonomic position of Fusarium oxysporum formae specialis cubense within the Fusarium oxysporum complex
Fusarium oxysporum is an asexual fungal species that includes human and animal pathogens and a
diverse range of nonpathogens. Pathogenic and nonpathogenic strains of this species can be
distinguished from each other with pathogenicity tests, but not with morphological analysis or sexual
compatibility studies. Substantial genetic diversity among isolates has led to the realization that F.
oxysporum represents a complex of cryptic species. F. oxysporum f. sp cubense (Foc), causal agent of
Fusariumwilt of banana, is one of the more than 150 plant pathogenic forms of F. oxysporum.Multi-gene
phylogenetic studies of Foc revealed at least eight phylogenetic lineages, a finding that was supported by
random amplified polymorphic DNAs, restriction fragment length polymorphisms and amplified
fragment length polymorphisms. Most of these lineages consist of isolates in closely related vegetative
compatibility groups, some of which possess opposite mating type alleles, MAT-1 and MAT-2; thus, the
evolutionary history of this fungus may have included recent sexual reproduction. The ability to cause
disease on all or some of the current race differential cultivars has evolved convergently in the taxon, as
members of some races appear in different phylogenetic lineages. Therefore, various factors including
co-evolution the plant host and horizontal gene transfer are thought to have shaped the evolutionary
history of Foc. This review discusses the evolution of Foc as a model formae specialis in F. oxysporum in
relation to recent research findings involving DNA-based studies.http://www.elsevier.com/locate/meegi
Fluctuation solution theory of pure fluids
Citation: Ploetz, E. A., Pallewela, G. N., & Smith, P. E. (2017). Fluctuation solution theory of pure fluids. Journal of Chemical Physics, 146(9), 13. doi:10.1063/1.4977040Fluctuation Solution Theory (FST) provides an alternative view of fluid thermodynamics in terms of pair fluctuations in the particle number and excess energy observed for an equivalent open system. Here we extend the FST approach to provide a series of triplet and quadruplet particle and excess energy fluctuations that can also be used to help understand the behavior of fluids. The fluctuations for the gas, liquid, and supercritical regions of three fluids (H2O, CO2, and SF6) are then determined from accurate equations of state. Many of the fluctuating quantities change sign on moving from the gas to liquid phase and, therefore, we argue that the fluctuations can be used to characterize gas and liquid behavior. Further analysis provides an approach to isolate contributions to the excess energy fluctuations arising from just the intermolecular interactions and also indicates that the triplet and quadruplet particle fluctuations are related to the pair particle fluctuations by a simple power law for large regions of the phase diagram away from the critical point. Published by AIP Publishing
Experimental triplet and quadruplet fluctuation densities and spatial distribution function integrals for pure liquids
Citation: Ploetz, E. A., Karunaweera, S., & Smith, P. E. (2015). Experimental triplet and quadruplet fluctuation densities and spatial distribution function integrals for pure liquids. Journal of Chemical Physics, 142(4), 14. doi:10.1063/1.4905562Fluctuation solution theory has provided an alternative view of many liquid mixture properties in terms of particle number fluctuations. The particle number fluctuations can also be related to integrals of the corresponding two body distribution functions between molecular pairs in order to provide a more physical picture of solution behavior and molecule affinities. Here, we extend this type of approach to provide expressions for higher order triplet and quadruplet fluctuations, and thereby integrals over the corresponding distribution functions, all of which can be obtained from available experimental thermodynamic data. The fluctuations and integrals are then determined using the International Association for the Properties of Water and Steam Formulation 1995 (IAPWS-95) equation of state for the liquid phase of pure water. The results indicate small, but significant, deviations from a Gaussian distribution for the molecules in this system. The pressure and temperature dependence of the fluctuations and integrals, as well as the limiting behavior as one approaches both the triple point and the critical point, are also examined. (C) 2015 AIP Publishing LLC
First Report of Fusarium oxysporum f. sp. cubense (Foc) Tropical Race 4 associated with Panama disease ofbanana outside Southeast Asia
Climate change impacts on banana yields around the world
This is the author accepted manuscript. The final version is available from Nature Research via the DOI in this r4ecordData availability:
All data used are publicly available and open access. All banana production data
sources are listed in Supplementary Table 1. All climatic and topographic data
sources are listed in the Methods.Nutritional diversity is a key element of food security1,2,3. However, research on the effects of climate change on food security has, thus far, focused on the main food grains4,5,6,7,8, while the responses of other crops, particularly those that play an important role in the developing world, are poorly understood. Bananas are a staple food and a major export commodity for many tropical nations9. Here, we show that for 27 countriesâaccounting for 86% of global dessert banana productionâa changing climate since 1961 has increased annual yields by an average of 1.37âtâhaâ1. Past gains have been largely ubiquitous across the countries assessed and African producers will continue to see yield increases in the future. However, global yield gains could be dampened or disappear, reducing to 0.59âtâhaâ1 and 0.19âtâhaâ1 by 2050 under the climate scenarios for Representative Concentration Pathways 4.5 and 8.5, respectively, driven by declining yields in the largest producers and exporters. By quantifying climate-driven and technology-driven influences on yield, we also identify countries at risk from climate change and those capable of mitigating its effects or capitalizing on its benefits.Biotechnology and Biological Sciences Research Council (BBSRC)European Union Horizon 202
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