526 research outputs found

    Two Approaches to Imputation and Adjustment of Air Quality Data from a Composite Monitoring Network

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    An analysis of air quality data is provided for the municipal area of Taranto characterized by high environmental risks, due to the massive presence of industrial sites with elevated environmental impact activities. The present study is focused on particulate matter as measured by PM10 concentrations. Preliminary analysis involved addressing several data problems, mainly: (i) an imputation techniques were considered to cope with the large number of missing data, due to both different working periods for groups of monitoring stations and occasional malfunction of PM10 sensors; (ii) due to the use of different validation techniques for each of the three monitoring networks, a calibration procedure was devised to allow for data comparability. Missing data imputation and calibration were addressed by three alternative procedures sharing a leave-one-out type mechanism and based on {\it ad hoc} exploratory tools and on the recursive Bayesian estimation and prediction of spatial linear mixed effects models. The three procedures are introduced by motivating issues and compared in terms of performance

    Two Approaches to Imputation and Adjustment of Air Quality Data from a Composite Monitoring Network

    Get PDF
    An analysis of air quality data is provided for the municipal area of Taranto characterized by high environmental risks, due to the massive presence of industrial sites with elevated environmental impact activities. The present study is focused on particulate matter as measured by PM10 concentrations. Preliminary analysis involved addressing several data problems, mainly: (i) an imputation techniques were considered to cope with the large number of missing data, due to both different working periods for groups of monitoring stations and occasional malfunction of PM10 sensors; (ii) due to the use of different validation techniques for each of the three monitoring networks, a calibration procedure was devised to allow for data comparability. Missing data imputation and calibration were addressed by three alternative procedures sharing a leave-one-out type mechanism and based on {\it ad hoc} exploratory tools and on the recursive Bayesian estimation and prediction of spatial linear mixed effects models. The three procedures are introduced by motivating issues and compared in terms of performance

    Bayesian analysis of the multivariate dependence of three transition water ecosystem classifications

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    The Water Framework Directive (WFD) recognizes benthic macroinvertebrates as a good biological quality element for transitional waters as they are the most exposed to natural variability patterns characteristic of these ecosystems, due to their life cycles and space-use behavior. Here, we address the ecological status classification issue for three lagoons in Apulia, using benthic macroinvertebrates and three proposed multimetric indices (namely M-AMBI, BITS and ISS), likely to respond differently to different sources of stress and natural variability. Lagoon classification is based on discretization by standard classification boundaries with only partial consideration of the natural variability of ecosystem properties and possible inaccuracies of the classification procedures. In order to investigate the possible contrasting behavior of the three classifications, we propose Bayesian hierarchical models in which the multimetric indices and their discrete counterparts are jointly modeled as function of abiotic covariates, external anthropogenic pressures indicators and spatio-temporal effects

    Yb-1 oncoprotein controls pi3k/akt pathway by reducing pten protein level

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    YB-1 is a multifunctional protein overexpressed in many types of cancer. It is a crucial oncoprotein that regulates cancer cell progression and proliferation. Ubiquitously expressed in human cells, YB-1 protein functions are strictly dependent on its subcellular localization. In the cytoplasm, where YB-1 is primarily localized, it regulates mRNA translation and stability. However, in response to stress stimuli and activation of PI3K and RSK signaling, YB-1 moves to the nucleus acting as a prosurvival factor. YB-1 is reported to regulate many cellular signaling pathways in different types of malignancies. Furthermore, several observations also suggest that YB-1 is a sensor of oxidative stress and DNA damage. Here we show that YB-1 reduces PTEN intracellular levels thus leading to PI3K/Akt pathway activation. Remarkably, PTEN reduction mediated by YB-1 overexpression can be observed in human immortalized keratinocytes and HEK293T cells and cannot be reversed by proteasome inhibition. Real-time PCR data indicate that YB-1 silencing up-regulates the PTEN mRNA level. Collectively, these observations indicate that YB-1 negatively controls PTEN at the transcript level and its overexpression could confer survival and proliferative advantage to PTEN proficient cancer cells

    Beyond generative models: superfast traversal, optimization, novelty, exploration and discovery (STONED) algorithm for molecules using SELFIES

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    Inverse design allows the generation of molecules with desirable physical quantities using property optimization. Deep generative models have recently been applied to tackle inverse design, as they possess the ability to optimize molecular properties directly through structure modification using gradients. While the ability to carry out direct property optimizations is promising, the use of generative deep learning models to solve practical problems requires large amounts of data and is very time-consuming. In this work, we propose STONED - a simple and efficient algorithm to perform interpolation and exploration in the chemical space, comparable to deep generative models. STONED bypasses the need for large amounts of data and training times by using string modifications in the SELFIES molecular representation. First, we achieve non-trivial performance on typical benchmarks for generative models without any training. Additionally, we demonstrate applications in high-throughput virtual screening for the design of drugs, photovoltaics, and the construction of chemical paths, allowing for both property and structure-based interpolation in the chemical space. Overall, we anticipate our results to be a stepping stone for developing more sophisticated inverse design models and benchmarking tools, ultimately helping generative models achieve wider adoption

    Revealing the coral habitat effect on benthopelagic fauna diversity in the Santa Maria di Leuca cold-water coral province using different devices and Bayesian hierarchical modelling

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    Data from two experimental longline surveys and two video inspections carried out in Santa Maria di Leuca cold-water coral province (Mediterranean Sea) during spring-autumn 2010 were used in order to compare the benthopelagic abundance and diversity between coral and non-coral habitats and between different devices. The sampling was carried out in two types of habitat: a coral habitat with carbonate mounds and a non-coral habitat characterized by intermound sea floor. A Bayesian hierarchical modelling approach to accommodate factors influencing community assemblages was used considering the number of species, the Shannon-Wiener diversity index and the two most abundant species represented by the European conger (Conger conger) and blackbelly rosefish (Helicolenus dactylopterus). A relevant effect of the habitat factor was observed for both the number of species and the diversity index, showing a higher species number and diversity index in the coral habitat than in the non-coral habitat. Concerning the relevance of fixed effects from the model on the probability of observing non-zero (positive) abundances, the devices considered, longline and baited lander, did not show different influence for either C. conger or H. dactylopterus. In the case of positive abundance, a relevant device effect was only observed for H. dactylopterus, showing higher abundances for longline than for baited lander. A habitat effect was detected, with positive abundances for both species in the coral habitat. This study proves that structurally complex habitats generated by cold-water corals influence the distribution and diversity of the benthopelagic fauna, and that the use of different devices can provide complementary useful results. Increased knowledge about the role of cold-water corals in the associated benthopelagic fauna could lead to better conservation of one of the most important hot spots of biodiversity in the Mediterranean Sea

    P02-10 Abnormal emotional responses to pleasant and unpleasant visual stimuli in first episode schizophrenia: f-MRI investigation

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    Aims:Affective deficits (flat affect, a diminished expression of emotion, anhedonia, and lowered ability to experience pleasure) are very common in schizophrenia. In emotion feeling, the crucial role of the insula, rather than of the primary somatosensory cortices, strongly suggests that the neural substrate for emotions is not merely sensorial. It is more likely that the activation of the insula representation of the viscero-motor activity is responsible for feeling of disgust. A recent MRI study demonstrated specific left anterior insular volume reduction in chronic schizophrenia patients: sustainable is the suggestion that emotion of disgust or of taste may be related to the experience of pleasure, which probably is compromise in schizophrenics.We investigated fMRI brain activations in first episode schizophrenic subjects with negative symptoms and in healthy subjects elicited by pleasant and unpleasant visual stimuli.Method:Ten first-episode schizophrenic subjects with normal IQ were recruited from the psychiatric service "SMILE" of San Salvatore Hospital and 10 healthy volunteers matched for age and education were scanned during observation of pleasant and unpleasant visual stimuli. Functional images were acquired with a 1.5T MRI scanner. Blood oxygenation level dependent (BOLD) contrast was obtained using EPI T2* weighted images.Results:The most important result of the study was the demonstration that anterior insula was activated by the exposure to disgusting stimula in normal subjects but not in schizophrenic subjects.Conclusion:This failure of the neural systems used to support emotional attribution is consistent with pervasive problems in experiencing emotions by schizophrenics
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