3,985 research outputs found
Synthesis and biological activity of a new class of antitumor cyclopeptides based on the solomonamides
Solomonamides A (1) and B (2) are novel natural products recently isolated from the marine sponge Theonella swinhoei [1]. Preliminary structural studies revealed an unprecedented cyclic peptide type structure. Interestingly, solomonamide A exhibits anti-inflammatory activity, showing potent reduction (60%) of inflammation at a very low concentration of 100 µg/kg in animal models. However, the scarcity of these compounds from their natural sources has been a drawback for further pharmacological assays. In fact, the anti-inflammatory activity of solomonamide B was not evaluated due to the limited amounts. This difficulty to access large amounts of these compounds makes quite difficult to gain insight into their biological profiles and mechanism of action and justifies the chemical synthesis of this new class of cyclic peptides. As a consequence, the solomonamides have been the subject of several synthetic efforts [2] notably by the Reddy group who has recently reported the first total synthesis of solomonamide B based on a intramolecular Heck reaction, which led to a revision of the initially proposed structure for 2 [3].Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Effect of Radiant Barrier Technology on Summer Attic Heat Load in South Texas
The objective of the study was to experimentally
evaluate the performance of radiant barriers in
single-family occupied housing units in South
Texas. Ceiling heat fluxes, attic air temperatures,
indoor air temperatures, ambient air temperatures.
roof temperatures, and solar radiation were
measured. Results of the radiant barrier experiment
using two side-by-side 600 ft2 units are presented.
Attic fiberglass insulation of nominal R-11 was
installed in the two apartments when the units were
last remodeled in 1974. The test houses responded
similarly to weather variations, that is, attic
temperature and heat flux profiles were similar in
magnitude prior to the retrofit. Residents of the
housing units were asked to set the thermostats at
76°F. Data were analyzed for periods of time which
had the greatest attic temperatures (11 a.m. - 11
p.m.) and for which the indoor temperature
differences were less than 1 percent. The results
showed that radiant barriers reduced ceiling heat
loads (on daily basis) by an average of 60 percent
Open cluster candidates in the VVVX area: VVVX CL 076 and CL 077
We are reporting some basic parameters of two newly discovered clusters, VVVX CL 076 and CL 077, recently discovered in the galactic disk area covered by the VISTA Variables in the Via Lactea eXtended (VVVX) ESO Public Survey. The preliminary analysis shows that both clusters are young and relatively close to the Sun.Peer reviewedFinal Published versio
The social amoeba Dictyostelium discoideum rescues Paraburkholderia hayleyella, but not P. agricolaris, from interspecific competition
Bacterial intracellular endosymbionts (hereafter called endosymbionts) can provide benefits for their eukaryotic hosts, but it is often less clear if endosymbionts themselves benefit from these relationships. The social amoeba Dictyostelium discoideum is known to associate with three species of Paraburkholderia endosymbionts including P. agricolaris and P. hayleyella. These Paraburkholderia are costly to host because they reduce the number of hardy spores produced by D. discoideum. However, they can be beneficial because they also allow D. discoideum to carry prey bacteria through the dispersal stage to seed new environments where a good bacterial food source may not be available. In laboratory experiments when no other species are present, P. hayleyella benefits from associating with D. discoideum while P. agricolaris does not. However, the presence of other species may influence symbioses like these. We tested if P. agricolaris and P. hayleyella benefit from the presence of their host in the context of resource competition with Klebsiella pneumoniae, D. discoideum’s typical laboratory prey. In the absence of D. discoideum, K. pneumoniae depressed the growth of both Paraburkholderia symbionts, consistent with competition between the bacteria. In addition, we found that P. hayleyella was harmed more by the presence of K. pneumoniae than was P. agricolaris. We also found that P. hayleyella was rescued from competition with K. pneumoniae by the presence of D. discoideum while P. agricolaris was not. This may be because P. hayleyella is more specialized as an endosymbiont of D. discoideum; it has a highly reduced genome compared to P. agricolaris and may have lost genes relevant for resource competition outside of its host
Overview of fungi and mycotoxin contamination in capsicum pepper and in its derivatives
Capsicum products are widely commercialised and consumed worldwide. These substrates present unusual nutritional characteristics for microbial growth. Despite this, the presence of spoilage fungi and the co-occurrence of mycotoxins in the pepper production chain have been commonly detected. The main aim of this work was to review the critical control points, with a focus on mycotoxin contamination, during the production, storage and distribution of Capsicum products from a safety perspective; outlining the important role of ecophysiological factors in stimulating or inhibiting mycotoxin biosynthesis in these food commodities. Moreover, the human health risks caused by the ingestion of peppers contaminated with mycotoxins were also reviewed. Overall, Capsicum and its derivative-products are highly susceptible to contamination by mycotoxins. Pepper crop production and further transportation, processing and storage are crucial for production of safe food.Chilean National Commission for Scientific and Technological Research
(CONICYT) which supports the J.C. PhD grant no
21181445, by Universidad de La Frontera (Temuco, Chile) with
partial funding from the Project DIUFRO DI18-0121 lead by C.S., and by the Portuguese Foundation for Science
and Technology (FCT) (UID/BIO/04469/2013 unit), COMPETE 2020 (POCI-01-0145-FEDER-006684) and the
BioTecNorte operation (NORTE-01-0145-FEDER-000004info:eu-repo/semantics/publishedVersio
Disparities among 2009 pandemic influenza A (H1N1) hospital admissions: A mixed methods analysis - Illinois, April-December 2009
During late April 2009, the first cases of 2009 pandemic influenza A (H1N1) (pH1N1) in Illinois were reported. On-going, sustained local transmission resulted in an estimated 500,000 infected persons. We conducted a mixed method analysis using both quantitative (surveillance) and qualitative (interview) data; surveillance data was used to analyze demographic distribution of hospitalized cases and follow-up interview data was used to assess health seeking behavior. Invitations to participate in a telephone interview were sent to 120 randomly selected Illinois residents that were hospitalized during April-December 2009. During April-December 2009, 2,824 pH1N1 hospitalizations occurred in Illinois hospitals; median age (interquartile range) at admission was 24 (range: 6-49) years. Hospitalization rates/100,000 persons for blacks and Hispanics, regardless of age or sex were 2-3 times greater than for whites (blacks, 36/100,000 (95% Confidence Interval ([95% CI], 33-39)); Hispanics, 35/100,000 [95%CI,32-37] (; whites, 13/100,000[95%CI, 12-14); p<0.001). Mortality rates were higher for blacks (0.9/100,000; p<0.09) and Hispanics (1/100,000; p<0.04) when compared with the mortality rates for whites (0.6/ 100,000). Of 33 interview respondents, 31 (94%) stated that they had heard of pH1N1 before being hospitalized, and 24 (73%) did not believed they were at risk for pH1N1. On average, respondents reported experiencing symptoms for 2 days (range: 1-7) before seeking medical care. When asked how to prevent pH1N1 infection in the future, the most common responses were getting vaccinated and practicing hand hygiene. Blacks and Hispanics in Illinois experienced disproportionate pH1N1 hospitalization and mortality rates. Public health education and outreach efforts in preparation for future influenza pandemics should include prevention messaging focused on perception of risk, and ensure community wide access to prevention messages and practices
Influence of storage environment on maize grain: CO2 production, dry matter losses and aflatoxins contamination
Poor storage of cereals, such as maize can lead to both nutritional losses and mycotoxin contamination. The aim of this study was to examine the respiration of maize either naturally contaminated or inoculated with Aspergillus flavus to examine whether this might be an early and sensitive indicator of aflatoxin (AF) contamination and relative storability risk. We thus examined the relationship between different interacting storage environmental conditions (0.80–0.99 water activity (aw) and 15–35°C) in naturally contaminated and irradiated maize grain + A. flavus on relative respiration rates (R), dry matter losses (DMLs) and aflatoxin B1 and B2 (AFB1-B2) contamination. Temporal respiration and total CO2 production were analysed by GC-TCD, and results used to calculate the DMLs due to colonisation. AFs contamination was quantified at the end of the storage period by HPLC MS/MS. The highest respiration rates occurred at 0.95 aw and 30–35°C representing between 0.5% and 18% DMLs. Optimum AFs contamination was at the same aw at 30°C. Highest AFs contamination occurred in maize colonised only by A. flavus. A significant positive correlation between % DMLs and AFB1 contamination was obtained (r = 0.866, p < 0.001) in the irradiated maize treatments inoculated with A. flavus. In naturally contaminated maize + A. flavus inoculum loss of only 0.56% DML resulted in AFB1 contamination levels exceeding the EU legislative limits for food. This suggests that there is a very low threshold tolerance during storage of maize to minimise AFB1 contamination. This data can be used to develop models that can be effectively used in enhancing management for storage of maize to minimise risks of mycotoxin contamination
Social Organizational Life Cycle Assessment (SO-LCA) and Organization 4.0: An easy-to-implement method
Organizations often face difficulties when measuring their social performance. The lack of international standards, the qualitative/quantitative nature of data, and the unavailability of primary sources all hinder social impact assessments, especially in manufacturing settings. To fill these gaps, the method proposes a simple application protocol of Social Organizational Life Cycle Assessment (SO-LCA), customized for an Italian ceramic tile manufacturer. The method leverages Industry 4.0 digital technologies to collect real-time primary and site-specific social data, making the social assessment dynamic. The managerial approach adopted for the selection of social metrics and weighting of indicators and indexes, can support the transition of the manufacturing organization into Organization 4.0. The method also provides a contribution to the operational validation of the UNEP guidelines by extending their area of application. Finally, the proposed method gives substance to social responsibility through social accounting, helping the organization to measure the correct social impact starting from the detailed data, namely the decisions made in the business and in production. • Social Organizational Life Cycle Assessment (SO-LCA) application protocol validated in Industry 4.0 environment. • Social metrics directly linked to production and business processes for the dynamic assessment of social performance. • Easy replicability of the method in other organizational contexts
Probing the fuzzy sphere regularisation in simulations of the 3d \lambda \phi^4 model
We regularise the 3d \lambda \phi^4 model by discretising the Euclidean time
and representing the spatial part on a fuzzy sphere. The latter involves a
truncated expansion of the field in spherical harmonics. This yields a
numerically tractable formulation, which constitutes an unconventional
alternative to the lattice. In contrast to the 2d version, the radius R plays
an independent r\^{o}le. We explore the phase diagram in terms of R and the
cutoff, as well as the parameters m^2 and \lambda. Thus we identify the phases
of disorder, uniform order and non-uniform order. We compare the result to the
phase diagrams of the 3d model on a non-commutative torus, and of the 2d model
on a fuzzy sphere. Our data at strong coupling reproduce accurately the
behaviour of a matrix chain, which corresponds to the c=1-model in string
theory. This observation enables a conjecture about the thermodynamic limit.Comment: 31 pages, 15 figure
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