101,776 research outputs found
Biology and management of freesia flower specking caused by Botrytis cinerea
Get PDFThere is no published research regarding postharvest infection of freesia flowers
by Botrytis cinerea. Although, infection problems have concerned freesia growers and
wholesalers in recent years. The overall objectives of this study were firstly to evaluate
the factors affecting B. cinerea postharvest disease establishment and secondly to
evaluate a range of novel potential treatments to reduce postharvest freesia infection.
These treatment options include plant activators such as acibenzolar-S-methyl and methyl
jasmonate and biotic (Aureobasidium pullulans) and abiotic (UV-C irradiation)
biological/elicitors agents.
Research was undertaken in an attempt to explain the variation in B. cinerea
incidence on cut freesia flowers as noted by the UK importer Zwetsloots & Sons Ltd. in
2000. Higher monthly rejections of freesia flower stems throughout 2000 due to B.
cinerea infection were recorded during spring (April-May), early summer (June) and
autumn (October). Comparatively higher proportions of rejected freesia stems were
associated with glasshouse temperatures ranging from 13-17°C.
In the presence of B. cinerea inoculum on freesia petal surface, temperature was
not a limiting factor for disease establishment. Incubation of artificially inoculated
freesia flowers at 12°C resulted in overall higher disease severity and lesion numbers
compared to flowers incubated at 5 or 20°C. In contrast, relative humidity was the most
important factor for postharvest infection by B. cinerea.
Elicitor based strategies for IPM using the potent activator acibenzolar provided
limited protection of freesia flowers against B. cinerea when applied postharvest.
Acibenzolar significantly reduced disease severity, lesion numbers and lesion diameters
compared to the untreated control when applied at 0.15 g A. 1. U1.
Methyl jasmonate (MeJA) applied as gas, pulse and spray generally suppressed B.
cinerea disease on cut freesia flowers. Disease severity, lesion numbers and lesion
diameters of flowers gassed with 0.1 μL MeJA L"' were reduced by 56,43 and 37%,
respectively compared to untreated control flowers. Gaseous MeJA treated freesia
flowers at 0.1 μL L"1 increased PPO activity by 57% compared to untreated controls 24h
after MeJA treatment. After 36h of incubation at 20°C, disease severity, lesion numbers and lesion diameters of gaseous MeJA treated flowers were reduced by 68,56 and 50%,
respectively, compared to the untreated controls. However, PAL activity in MeJA treated
freesia flowers did not decrease significantly over time compared to untreated control 12h
post-inoculation and thereafter. These findings suggest that MeJA treatment might
suppress the action of PAL in the phenylpropanoid pathway and consequently block SA
production.
UV-C irradiation might be used in an integrated postharvest disease management
program for freesia flowers. UV-C irradiation after artificial inoculation resulted in
markedly reduced B. cinerea disease severity scores and lesion numbers. In detail, UV-C
irradiation of cut freesia flowers with 0.5,1,2.5 and 5 kJ m''` reduced disease severity by
up to 44,70,74 and 59% and lesion numbers by up to 37,62,68 and 60%, respectively.
UV-C irradiation at 1 kJ M-2 before artificial inoculation slightly reduced disease severity
and lesion numbers possibly by inducing defence responses. However, the limited
disease suppression suggested that apparently B. cinerea could overcome the UV-C
induced effect.
The effect of preharvest treatments on freesia crops with acibenzolar was
investigated in glasshouse trials in view to suppress postharvest B. cinerea infection via
SAR induction. Acibenzolar was effective in selected treatments and conditions.
Disease pressure varied over the 3 years and over varieties tested. However, it was
unclear whether acibenzolar induced systemic and/or local defence responses. The latter
was supported by biochemical investigations in 2001 which suggested that acibenzolar
did not induce PAL activity.
In contrast, preharvest MeJA treatment resulted in markedly systemic protection
of treated flowers compared to untreated ones. MeJA efficacy was dependent on variety
and on postharvest incubation temperatures. Disease severity, lesion numbers and lesion
diameters on MeJA treated freesia var. `Dukaat' flowers incubated at 20°C were reduced
by 56,61, and 49% compared to controls, respectively. Also, disease severity, lesion
numbers and lesion diameters on MeJA treated `Cote d'Azur' flowers incubated at 20°C
were reduced by 36,26, and 49% compared to controls, respectively
Letter, [Author unclear] to Paulina T. Merritt
No full textHandwritten letter to Paulina Merritt from an unknown author, October 1, 1876.
Handwritten biographical information on Paulina T. McClung Merritt
No full textA handwritten biography of Paulina T. McClung Merritt by an unknown author, 1892.
Heterogeneous and tissue-specific regulation of effector T cell responses by IFN-gamma during Plasmodium berghei ANKA infection.
Get PDFIFN-γ and T cells are both required for the development of experimental cerebral malaria during Plasmodium berghei ANKA infection. Surprisingly, however, the role of IFN-γ in shaping the effector CD4(+) and CD8(+) T cell response during this infection has not been examined in detail. To address this, we have compared the effector T cell responses in wild-type and IFN-γ(-/-) mice during P. berghei ANKA infection. The expansion of splenic CD4(+) and CD8(+) T cells during P. berghei ANKA infection was unaffected by the absence of IFN-γ, but the contraction phase of the T cell response was significantly attenuated. Splenic T cell activation and effector function were essentially normal in IFN-γ(-/-) mice; however, the migration to, and accumulation of, effector CD4(+) and CD8(+) T cells in the lung, liver, and brain was altered in IFN-γ(-/-) mice. Interestingly, activation and accumulation of T cells in various nonlymphoid organs was differently affected by lack of IFN-γ, suggesting that IFN-γ influences T cell effector function to varying levels in different anatomical locations. Importantly, control of splenic T cell numbers during P. berghei ANKA infection depended on active IFN-γ-dependent environmental signals--leading to T cell apoptosis--rather than upon intrinsic alterations in T cell programming. To our knowledge, this is the first study to fully investigate the role of IFN-γ in modulating T cell function during P. berghei ANKA infection and reveals that IFN-γ is required for efficient contraction of the pool of activated T cells
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Urban carbon and energy analysis: calculation of energy flows and emissions from residential housing clusters and assessment of sustainable energy options
No full textIn the UK, the domestic sector accounts for around 30% of fuel-use and energy related carbon emissions, and therefore has the potential to deliver significant reductions in carbon dioxide emissions. The purpose of this work is to form and examine various heat and electricity supply scenarios at the street-level and identify which of these scenarios offer the most potential to reduce consumption of resources and carbon dioxide emissions. The path to realisation of a reduction in carbon emissions from the domestic sector incorporates three consecutive steps: (1) saving energy, (2) use of renewables and (3) use energy as efficiently as possible, including fossil fuels. In reality, there is a strong interaction between all three steps and often they take place simultaneously. The first two steps tend to minimise the use of fossil fuels, but not to eliminate them. In this work it is recognised that in mature urban regions fossil fuels cannot be readily displaced completely, but can be used in a more efficient way. This research considers what can be achieved by applying at or near to market technologies at the street level microgrid scale, such as Combined Heat and Power (CHP). The renewable energy technologies considered were photovoltaics (PV) for electricity generation, solar thermal for domestic hot water heating and ground source heat pumps (GSHP) for space heating. For the development of the models, the transient simulation package TRNSYS was used and a residential area in Southampton that represents a typical UK area, was chosen as a case study. The notion of combining a number of houses to form a local microgrid proved to be beneficial for all the technologies examined in this research. It was shown that renewable energy microtechnologies can improve their carbon performance up to 10% when operating as a microgrid, whilst estimated benefits were even greater for CHP systems. Parallel operation strategies were also investigated and it was shown that they have the potential to deliver further savings from microgrid schemes. Microgrids, although their high capital costs, were estimated to have better financial performance compared with the single house level for many of the cases examined. Increased generation and lower heating demand were the key outcomes due to the impact of change in climat
Pelevin’s Trinity in the novel “t”: author – protagonist – reader
No full textThe article attempts to interpret Pelevin's artistic strategy in the novel "T" by exploring its subject organization and addressing the key problems of the author, the protagonist, and the reader as they are seen by the researcher. The article analyzes the peculiarities of constructing the narrative reality in the novel "T", and goes on to discuss Pelevin's philosophic models of the development of the humankind, and the emergence of his new anthropology
Supplementary_material – Supplemental material for CD8<sup>+</sup> PD-1<sup>+</sup> T-cells and PD-L1<sup>+</sup> circulating tumor cells in chemotherapy-naïve non-small cell lung cancer: towards their clinical relevance?
No full textSupplemental material, Supplementary_material for CD8+ PD-1+ T-cells and PD-L1+ circulating tumor cells in chemotherapy-naïve non-small cell lung cancer: towards their clinical relevance? by Athanasios Kotsakis, Galatea Kallergi, Despoina Aggouraki, Zaharoula Lyristi, Filippos Koinis, Eleni Lagoudaki, Anastasios Koutsopoulos, Vassilis Georgoulias and Eleni-Kyriaki Vetsika in Therapeutic Advances in Medical Oncology</p
Measuring industry-science links through inventor-author relations: A profiling method
Get PDFIn this pilot study we examine the performance of text-based profiling in recovering a set of validated inventor-author links. In a first step we match patents and publications solely based on their similarity in content. Next, we compare inventor and author names on the highest ranked matches for the occurrence of name matches. Finally, we compare these candidate matches with the names listed in a validated set of inventor-author names. Our text-based profile methodology performs significantly better than a random matching of patents and publications, suggesting that text-based profiling is a valuable complementary tool to the name searches used in previous studies.innovation; industry-science links; text-based profiling;
Quasimetric Embeddings and Their Applications
Get PDFWe study generalizations of classical metric embedding results to the case of quasimetric spaces; that is, spaces that do not necessarily satisfy symmetry. Quasimetric spaces arise naturally from the shortest-path distances on directed graphs. Perhaps surprisingly, very little is known about low-distortion embeddings for quasimetric spaces.
Random embeddings into ultrametric spaces are arguably one of the most successful geometric tools in the context of algorithm design. We extend this to the quasimetric case as follows. We show that any n-point quasimetric space supported on a graph of treewidth t admits a random embedding into quasiultrametric spaces with distortion O(t*log^2(n)), where quasiultrametrics are a natural generalization of ultrametrics. This result allows us to obtain t*log^{O(1)}(n)-approximation algorithms for the Directed Non-Bipartite Sparsest-Cut and the Directed Multicut problems on n-vertex graphs of treewidth t, with running time polynomial in both n and t.
The above results are obtained by considering a generalization of random partitions to the quasimetric case, which we refer to as random quasipartitions. Using this definition and a construction of [Chuzhoy and Khanna 2009] we derive a polynomial lower bound on the distortion of random embeddings of general quasimetric spaces into quasiultrametric spaces. Finally, we establish a lower bound for embedding the shortest-path quasimetric of a graph G into graphs that exclude G as a minor. This lower bound is used to show that several embedding results from the metric case do not have natural analogues in the quasimetric setting
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