38 research outputs found
Applying fuzzy logic to assess the biogeographical risk of dengue in South America
Background Over the last decade, reports about dengue cases have increase worldwide, which is particularly worrisome in South America due to the historic record of dengue outbreaks from the seventeenth century until the first half of the twentieth century. Dengue is a viral disease that involves insect vectors, namely Aedes aegypti and Ae. albopictus, which implies that, to prevent and combat outbreaks, it is necessary to understand the set of ecological and biogeographical factors affecting both the vector species and the virus. Methods We contribute with a methodology based on fuzzy logic that is helpful to disentangle the main factors that determine favorable environmental conditions for vectors and diseases. Using favorability functions as fuzzy logic modelling technique and the fuzzy intersection, union and inclusion as fuzzy operators, we were able to specify the territories at biogeographical risk of dengue outbreaks in South America. Results Our results indicate that the distribution of Ae. aegypti mostly encompasses the biogeographical framework of dengue in South America, which suggests that this species is the principal vector responsible for the geographical extent of dengue cases in the continent. Nevertheless, the intersection between the favorability for dengue cases and the union of the favorability for any of the vector species provided a comprehensive map of the biogeographical risk for dengue. Conclusions Fuzzy logic is an appropriate conceptual and operational tool to tackle the nuances of the vector-illness biogeographical interaction. The application of fuzzy logic may be useful in decision-making by the public health authorities to prevent, control and mitigate vector-borne diseases
Coherent Population Trapping of Single Spins in Diamond Under Optical Excitation
Coherent population trapping is demonstrated in single nitrogen-vacancy
centers in diamond under optical excitation. For sufficient excitation power,
the fluorescence intensity drops almost to the background level when the laser
modulation frequency matches the 2.88 GHz splitting of the ground states. The
results are well described theoretically by a four-level model, allowing the
relative transition strengths to be determined for individual centers. The
results show that all-optical control of single spins is possible in diamond.Comment: minor correction
Science results from the imaging Fourier transform spectrometer SpIOMM
SpIOMM is an imaging Fourier transform spectrometer designed to obtain the
visible range (350 to 850 nm) spectrum of every light source in a circular
field of view of 12 arcminutes in diameter. It is attached to the 1.6-m
telescope of the Observatoire du Mont Megantic in southern Quebec. We present
here some results of three successful observing runs in 2007, which highlight
SpIOMMs capabilities to map emission line objects over a very wide field of
view and a broad spectral range. In particular, we discuss data cubes from the
planetary nebula M27, the supernova remnants NGC 6992 and M1, the barred spiral
galaxy NGC7479, as well as Stephans quintet, an interacting group of galaxies.Comment: 10 pages, 7 figures, to appear in "Ground-based and Airborne
Instrumentation for Astronomy II", SPIE conference, Marseille, 23-28 June
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Estimating how inflated or obscured effects of climate affect forecasted species distribution
Climate is one of the main drivers of species distribution. However, as different environmental factors tend to co-vary, the
effect of climate cannot be taken at face value, as it may be either inflated or obscured by other correlated factors. We used
the favourability models of four species (Alytes dickhilleni, Vipera latasti, Aquila fasciata and Capra pyrenaica) inhabiting
Spanish mountains as case studies to evaluate the relative contribution of climate in their forecasted favourability by using
variation partitioning and weighting the effect of climate in relation to non-climatic factors. By calculating the pure effect of
the climatic factor, the pure effects of non-climatic factors, the shared climatic effect and the proportion of the pure effect of
the climatic factor in relation to its apparent effect (r), we assessed the apparent effect and the pure independent effect of
climate. We then projected both types of effects when modelling the future favourability for each species and combination
of AOGCM-SRES (two Atmosphere-Ocean General Circulation Models: CGCM2 and ECHAM4, and two Special Reports on
Emission Scenarios (SRES): A2 and B2). The results show that the apparent effect of climate can be either inflated (overrated)
or obscured (underrated) by other correlated factors. These differences were species-specific; the sum of favourable areas
forecasted according to the pure climatic effect differed from that forecasted according to the apparent climatic effect by
about 61% on average for one of the species analyzed, and by about 20% on average for each of the other species. The pure
effect of future climate on species distributions can only be estimated by combining climate with other factors. Transferring
the pure climatic effect and the apparent climatic effect to the future delimits the maximum and minimum favourable areas
forecasted for each species in each climate change scenario.Ministerio de Ciencia e Innovación and FEDER (project CGL2009-11316/BOS). D. Romero is a PhD student at the University of Malaga with a grant of the Ministerio de Educacio´n y Ciencia (AP 2007-03633
Impact of Olive Harvesting Date on Virgin Olive Oil Volatile Composition in Four Spanish Varieties
The unique sensory characteristics of extra virgin olive oil (EVOO) depend upon its volatile composition. This work investigates the impact of olive fruit harvesting time and growing location on the volatile composition of the obtained EVOO, on four typical Spanish olive varieties (Cornicabra, Picual, Castellana, Manzanilla Cacereña). Several growing locations within the Madrid region (Spain) are studied to assess the natural variability attributed to the environmental factors. Aroma compounds are analyzed by solid-phase microextraction coupled with gas-chromatography and mass spectrometry, and sensory analysis. A considerable different behavior is observed depending on the olive variety and ripening stage. Statistically significant differences are obtained for volatile compounds biosynthesized from the lipoxygenase pathway and other fatty acid metabolism routes, which results in significant differences in their aroma profiles. Practical applications: These results have practical applicability for the olive oil industry and regulatory bodies. For example, for protected designation of origin EVOOs the aroma profile needs to be consistent over different production lots. The outcome of this research is of interest to the olive oil industry to get a better insight into the expected variability and interactions among cultivars, small pedoclimatic differences within the same broader area, and the harvesting date on the sensory and volatile profile of the resulting EVOO
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The p53 transcriptional response across tumor types reveals core and senescence-specific signatures modulated by long noncoding RNAs.
The p53 pathway is a universal tumor suppressor mechanism that limits tumor progression by triggering apoptosis or permanent cell cycle arrest, called senescence. In recent years, efforts to reactivate p53 function in cancer have proven to be a successful therapeutic strategy in murine models and have gained traction with the development of a range of small molecules targeting mutant p53. However, knowledge of the downstream mediators of p53 reactivation in different oncogenic contexts has been limited. Here, we utilized a panel of murine cancer cell lines from three distinct tumor types susceptible to alternative outcomes following p53 restoration to define unique and shared p53 transcriptional signatures. While we found that the majority of p53-bound sites and p53-responsive transcripts are tumor-type specific, analysis of shared targets identified a core signature of genes activated by p53 across all contexts. Furthermore, we identified repression of E2F and Myc target genes as a key feature of senescence. Characterization of p53-induced transcripts revealed core and senescence-specific long noncoding RNAs (lncRNAs) that are predominantly chromatin associated and whose production is coupled to cis-regulatory activities. Functional investigation of the contributions of p53-induced lncRNAs to p53-dependent outcomes highlighted Pvt1b, the p53-dependent isoform of Pvt1, as a mediator of p53-dependent senescence via Myc repression. Inhibition of Pvt1b led to decreased activation of senescence markers and increased levels of markers of proliferation. These findings shed light on the core and outcome-specific p53 restoration signatures across different oncogenic contexts and underscore the key role of the p53-Pvt1b-Myc regulatory axis in mediating proliferative arrest
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The p53 transcriptional response across tumor types reveals core and senescence-specific signatures modulated by long noncoding RNAs.
The p53 pathway is a universal tumor suppressor mechanism that limits tumor progression by triggering apoptosis or permanent cell cycle arrest, called senescence. In recent years, efforts to reactivate p53 function in cancer have proven to be a successful therapeutic strategy in murine models and have gained traction with the development of a range of small molecules targeting mutant p53. However, knowledge of the downstream mediators of p53 reactivation in different oncogenic contexts has been limited. Here, we utilized a panel of murine cancer cell lines from three distinct tumor types susceptible to alternative outcomes following p53 restoration to define unique and shared p53 transcriptional signatures. While we found that the majority of p53-bound sites and p53-responsive transcripts are tumor-type specific, analysis of shared targets identified a core signature of genes activated by p53 across all contexts. Furthermore, we identified repression of E2F and Myc target genes as a key feature of senescence. Characterization of p53-induced transcripts revealed core and senescence-specific long noncoding RNAs (lncRNAs) that are predominantly chromatin associated and whose production is coupled to cis-regulatory activities. Functional investigation of the contributions of p53-induced lncRNAs to p53-dependent outcomes highlighted Pvt1b, the p53-dependent isoform of Pvt1, as a mediator of p53-dependent senescence via Myc repression. Inhibition of Pvt1b led to decreased activation of senescence markers and increased levels of markers of proliferation. These findings shed light on the core and outcome-specific p53 restoration signatures across different oncogenic contexts and underscore the key role of the p53-Pvt1b-Myc regulatory axis in mediating proliferative arrest
Toward quantum information processing using EIT in diamond
We describe how a quantum non-demolition device bascd on electromagnetically-induced transparency in solidstate atom-like systems could be realized. Such a resource, requiring only weak optical nonlinearities, could potentially enable photonic quantum information processing (QIP) that is much more efficient than QIP based on linear optics alone. As an example, we show how a parity gate could be constructed. A particularly interesting physical system for constructing devices is the nitrogen-vacancy defect in diamond, but the excited-state structure for this system is unclear in the existing literature. We include some of our latest spectroscopic results that indicate that the optical transitions are generally not spin-preserving, even at zero magnetic field, which allows the affiliation of a A-type system.14 page(s