4,679 research outputs found
Sensitivity-Based Model of Low Voltage Distribution Systems with Distributed Energy Resources
A key issue in Low Voltage(LV) distribution systems is to identify strategies for the optimal management and control in the presence of Distributed Energy Resources (DERs). To reduce the number of variables to be monitored and controlled, virtual levels of aggregation, called Virtual Microgrids (VMs), are introduced and identified by using new models of the distribution system. To this aim, this paper, revisiting and improving the approach outlined in a conference paper, presents a sensitivity-based model of an LV distribution system, supplied by a Medium/Low Voltage (MV/LV) substation and composed by several feeders, which is suitable for the optimal management and control of the grid and for VM definition. The main features of the proposed method are: it evaluates the sensitivity coefficients in a closed form; it provides an overview of the sensitivity of the network to the variations of each DER connected to the grid; and it presents a limited computational burden. A comparison of the proposed method with both the exact load flow solutions and a perturb-and-observe method is discussed in a case study. Finally, the method is used to evaluate the impact of the DERs on the nodal voltages of the network
Towards realistic laparoscopic image generation using image-domain translation
none5openMarzullo, Aldo; Moccia, Sara; Catellani, Michele; Calimeri, Francesco; Momi, Elena DeMarzullo, Aldo; Moccia, Sara; Catellani, Michele; Calimeri, Francesco; Momi, Elena D
Odour Detection Methods: Olfactometry and Chemical Sensors
The complexity of the odours issue arises from the sensory nature of smell. From the evolutionary point of view olfaction is one of the oldest senses, allowing for seeking food, recognizing danger or communication: human olfaction is a protective sense as it allows the detection of potential illnesses or infections by taking into account the odour pleasantness/unpleasantness. Odours are mixtures of light and small molecules that, coming in contact with various human sensory systems, also at very low concentrations in the inhaled air, are able to stimulate an anatomical response: the experienced perception is the odour. Odour assessment is a key point in some industrial production processes (i.e., food, beverages, etc.) and it is acquiring steady importance in unusual technological fields (i.e., indoor air quality); this issue mainly concerns the environmental impact of various industrial activities (i.e., tanneries, refineries, slaughterhouses, distilleries, civil and industrial wastewater treatment plants, landfills and composting plants) as sources of olfactory nuisances, the top air pollution complaint. Although the human olfactory system is still regarded as the most important and effective âanalytical instrumentâ for odour evaluation, the demand for more objective analytical methods, along with the discovery of materials with chemo-electronic properties, has boosted the development of sensor-based machine olfaction potentially imitating the biological system. This review examines the state of the art of both human and instrumental sensing currently used for the detection of odours. The olfactometric techniques employing a panel of trained experts are discussed and the strong and weak points of odour assessment through human detection are highlighted. The main features and the working principles of modern electronic noses (E-Noses) are then described, focusing on their better performances for environmental analysis. Odour emission monitoring carried out through both the techniques is finally reviewed in order to show the complementary responses of human and instrumental sensing
Geo-archaeology of the Roman palaeosurface of Sena Gallica (Senigallia, Italy)
ABSTRACTSena Gallica (Senigallia), in the northern Marche region, was the first Roman colony on the Adriatic coast founded at the beginning of the third century BC. This research adopted an integrated approach to different information sources that combines old and new data, archaeological excavations, topographic and geophysical surveys, and geological and geomorphological analyses. The data are managed within a GIS and supported by 3D modelling. One of the results of this work is a map which represents the geomorphological setting of the Roman colony, close to the mouth of the Misa river. The settlement exploited the top-surface of the uppermost Pleistoceneâearly Holocene coastal fan of the Misa river, now only preserved at the apex sector truncated seaward by wave erosion. The top-surface of the fan apex, in turn, was partly re-incised by stream erosion producing a series of slight topographic mounds, which were selected for the earliest human settlement (V-IV c. BC). Some of the mounds resulted in a pr..
Pro-inflammatory RNA:DNA hybrids are p53 independently boosted by hyperbaric oxygen: a subcellular distribution analysis by automated quantitative imaging
Purpose:
RNA:DNA hybrids are co-transcriptional products with acknowledged cytoplasmic pro-inflammatory role as activators of the cGAS-STING pathway. We recently proved them also as radiation-induced senescence messages for the abscopal
effect mediation, demonstrating the need for a functional p53 for their production and release in A549 and H1299 tumour cells. However, little is known about their role under different stress conditions, especially in cancer cells.
Methods:
In this work, we open the investigation making use of automated quantitative imaging to characterize the hybrid subcellular distribution in HeLa cells grown under different oxygen pressures or exposed to different ionizing radiation
doses. After cell imaging by confocal fluorescent microscopy, we apply automated imaging methods developed on purpose to quantify hybrid foci and nuclear cluster intensity, regional and local density and dimension.
Results:
We show that alteration of culture oxygenation increases hybrid cytoplasmic presence, especially when caused by an hyperoxic environment, with evident hybrid gathering at the cell membrane. Ionizing radiations always fail to increase
hybrids, in accordance with the absence of functional p53 in HeLa cells. However, dose-dependent effects are still evident and suggest a threshold dose of 7.5 Gy for remarkable hybrid reduction.
Conclusion:
Together with our previous results, these data demonstrate for the first time that different types of stress can increase hybrid production in cancer cells and by at least two different pathways, one p53-dependent triggerable by ionizing radiations and one p53-independent triggerable by oxidative stress. Together, our findings provide a starting point for understanding hybrid role in tumour stress response
Neuropsychiatric performance and treatment of hepatitis C with direct-acting antivirals: a prospective study
Background: Since direct-acting antivirals (DAAs) have been approved for the treatment of hepatitis C virus (HCV) infection, a small series of patients with new-onset neuropsychiatric alterations have been referred to us. We therefore set out to study neuropsychiatric function in relation to DAAs prospectively.
Methods: Ten patients with cirrhosis and 12 post-liver transplant (post-LT) patients were enrolled. All underwent wake electroencephalography (EEG) and a neuropsychological evaluation (paper and pencil battery, simple/choice reaction times, working memory task) at baseline, at the end of treatment with DAAs and after 6 months. At the same time points, full blood count, liver/kidney function tests, quantitative HCV RNA, ammonia and immunosuppressant drug levels were obtained, as appropriate.
Results: Patients with cirrhosis were significantly older than post-LT patients (65\ub112 vs 55\ub17 years; P<0.05). Neuropsychological performance and wake EEG were comparable in the two groups at baseline. At the end of a course of treatment with DAAs, a significant slowing in choice reaction times and in the EEG (increased relative delta power) was observed in patients with cirrhosis, which resolved after 6 months. In contrast, no significant changes over time were observed in the neuropsychiatric performance of post-LT patients. No significant associations were observed between neuropsychiatric performance and stand-alone/combined laboratory variables.
Conclusion: Some degree of neuropsychiatric impairment was observed in relation to treatment with DAAs in patients with cirrhosis, but not in post-LT patients, suggesting that the former may be sensitive to mild DAA neurotoxicity
Using spatial-temporal ensembles of convolutional neural networks for lumen segmentation in ureteroscopy
Purpose: Ureteroscopy is an efficient endoscopic minimally invasive technique
for the diagnosis and treatment of upper tract urothelial carcinoma (UTUC).
During ureteroscopy, the automatic segmentation of the hollow lumen is of
primary importance, since it indicates the path that the endoscope should
follow. In order to obtain an accurate segmentation of the hollow lumen, this
paper presents an automatic method based on Convolutional Neural Networks
(CNNs).
Methods: The proposed method is based on an ensemble of 4 parallel CNNs to
simultaneously process single and multi-frame information. Of these, two
architectures are taken as core-models, namely U-Net based in residual
blocks() and Mask-RCNN(), which are fed with single still-frames
. The other two models (, ) are modifications of the former
ones consisting on the addition of a stage which makes use of 3D Convolutions
to process temporal information. , are fed with triplets of frames
(, , ) to produce the segmentation for .
Results: The proposed method was evaluated using a custom dataset of 11
videos (2,673 frames) which were collected and manually annotated from 6
patients. We obtain a Dice similarity coefficient of 0.80, outperforming
previous state-of-the-art methods.
Conclusion: The obtained results show that spatial-temporal information can
be effectively exploited by the ensemble model to improve hollow lumen
segmentation in ureteroscopic images. The method is effective also in presence
of poor visibility, occasional bleeding, or specular reflections
Theatre is a valid add-on therapeutic intervention for emotional rehabilitation of parkinson's disease patients
Conventional medical treatments of Parkinson's disease (PD) are effective on motor disturbances but may have little impact on nonmotor symptoms, especially psychiatric ones. Thus, even when motor symptomatology improves, patients might experience deterioration in their quality of life. We have shown that 3 years of active theatre is a valid complementary intervention for PD as it significantly improves the well-being of patients in comparison to patients undergoing conventional physiotherapy. Our aim was to replicate these findings while improving the efficacy of the treatment. We ran a single-blinded pilot study lasting 15 months on 24 subjects with moderate idiopathic PD. 12 were assigned to a theatre program in which patients underwent "emotional" training. The other 12 underwent group physiotherapy. Patients were evaluated at the beginning and at the end of their treatments, using a battery of eight clinical and five neuropsychological scales. We found that the emotional theatre training improved the emotional well-being of patients, whereas physiotherapy did not. Interestingly, neither of the groups showed improvements in either motor symptoms or cognitive abilities tested by the neuropsychological battery. We confirmed that theatre therapy might be helpful in improving emotional well-being in PD
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