124 research outputs found
Comparison between 3D-Var and 4D-Var data assimilation methods for the simulation of a heavy rainfall case in central Italy
Abstract. This work aims to provide a comparison between three dimensional and four dimensional variational data assimilation methods (3D-Var and 4D-Var) for a heavy rainfall case in central Italy. To evaluate the impact of the assimilation of reflectivity and radial velocity acquired from Monte Midia Doppler radar into the Weather Research Forecasting (WRF) model, the quantitative precipitation forecast (QPF) is used.The two methods are compared for a heavy rainfall event that occurred in central Italy on 14 September 2012 during the first Special Observation Period (SOP1) of the HyMeX (HYdrological cycle in Mediterranean EXperiment) campaign. This event, characterized by a deep low pressure system over the Tyrrhenian Sea, produced flash floods over the Marche and Abruzzo regions, where rainfall maxima reached more than 150 mm 24 h−1.To identify the best QPF, nine experiments are performed using 3D-Var and 4D-Var data assimilation techniques. All simulations are compared in terms of rainfall forecast and precipitation measured by the gauges through three statistical indicators: probability of detection (POD), critical success index (CSI) and false alarm ratio (FAR). The assimilation of conventional observations with 4D-Var method improves the QPF compared to 3D-Var. In addition, the use of radar measurements in 4D-Var simulations enhances the performances of statistical scores for higher rainfall thresholds
A Network of X-Band Meteorological Radars to Support the Motorway System (Campania Region Meteorological Radar Network Project)
he transport sector and road infrastructures are very sensitive to the issues connected to the atmospheric conditions. The latter constitute a source of relevant risk, especially for roads running in mountainous areas, where a wide spectrum of meteorological phenomena, such as rain showers, snow, hail, wind gusts and ice, threatens drivers’ safety. In such contexts, to face out critical situations it is essential to develop a monitoring system that is able to capillary surveil specific sectors or very small basins, providing real time information that may be crucial to preserve lives and assets. In this work, we present the results of the “Campania Region Meteorological Radar Network”, which is focused on the development of X-band radar-based meteorological products that can support highway traffic management and maintenance. The X-band measurements provided by two single-polarization systems, properly integrated with the observations supplied by disdrometers and conventional automatic weather stations, were involved in the following main tasks: (i) the development of a radar composite product; (ii) the devise of a probability of hail index; (iii) the real time discrimination of precipitation type (rain, mixed and snow); (iv) the development of a snowfall rate estimator. The performance of these products was assessed for two case studies, related to a relevant summer hailstorm (which occurred on 1 August 2020) and to a winter precipitation event (which occurred on 13 February 2021). In both cases, the X-band radar-based tools proved to be useful for the stakeholders involved in the management of highway traffic, providing a reliable characterization of precipitation events and of the fast-changing vertical structure of convective cells
Calibrating the Dynamic Energy Simulation Model for an Existing Building: Lessons Learned from a Collective Exercise
Calibration of the existing building simulation model is key to correctly evaluating the
energy savings that are achievable through retrofit. However, calibration is a non-standard phase
where different approaches can possibly lead to different models. In this study, an existing residential
building is simulated in parallel by four research groups with different dynamic simulation
tools. Manual/automatic methodologies and basic/detailed measurement data sets are used. The
calibration is followed by a validation on two evaluation periods. Monitoring data concerning the
windows opening by the occupants are used to analyze the calibration outcomes. It is found that for
a good calibration of a model of a well-insulated building, the absence of data regarding the users’
behavior is more critical than uncertainty on the envelope properties. The automatic approach is
more effective in managing the model complexity and reaching a better performing calibration, as the
RMSE relative to indoor temperature reaches 0.3 C compared to 0.4–0.5 C. Yet, a calibrated model’s
performance is often poor outside the calibration period (RMSE increases up to 10.8 times), and thus,
the validation is crucial to discriminate among multiple solutions and to refine them, by improving
the users’ behavior modeling
Assessment of Sexual Dysfunction in Cervical Cancer Patients after Different Treatment Modality: A Systematic Review
Background and Objectives: Cervical cancer is a leading cause of mortality among women. Chemo-radiation followed by interventional radiotherapy (IRT) is the standard of care for stage IB-IVA FIGO. Several studies have shown that image-guided adaptive IRT resulted in excellent local and pelvic control, but it is associated with vaginal toxicity and intercourse problems. The purpose of this review is to evaluate the dysfunctions of the sexual sphere in patients with cervical cancer undergoing different cervix cancer treatments. Materials and Methods: We performed a comprehensive literature search using Pub med, Scopus and Cochrane to identify all the full articles evaluating the dysfunctions of the sexual sphere. ClinicalTrials.gov was searched for ongoing or recently completed trials, and PROSPERO was searched for ongoing or recently completed systematic reviews. Results: One thousand three hundred fifty-six women included in five studies published from 2016 to 2022 were analyzed. The median age was 50 years (range 46-56 years). The median follow-up was 12 months (range 0-60). Cervical cancer diagnosis and treatment (radiotherapy, chemotherapy and surgery) negatively affected sexual intercourse. Sexual symptoms such as fibrosis, strictures, decreased elasticity and depth and mucosal atrophy promote sexual dysfunction by causing frigidity, lack of lubrication, arousal, orgasm and libido and dyspareunia. Conclusions: Physical, physiological and social factors all contribute to the modification of the sexual sphere. Cervical cancer survivors who were irradiated have lower sexual and vaginal function than the normal population. Although there are cures for reducing discomfort, effective communication about sexual dysfunctions following treatment is essential
Tailoring the Structure of Cell Penetrating DNA and RNA Binding Nucleopeptides
Synthetic nucleic acid interactors represent an exciting research field due to their biotechnological and potential therapeutic applications. The translation of these molecules into drugs is a long and difficult process that justifies the continuous research of new chemotypes endowed with favorable binding, pharmacokinetic and pharmacodynamic properties. In this scenario, we describe the synthesis of two sets of homo-thymine nucleopeptides, in which nucleobases are inserted in a peptide structure, to investigate the role of the underivatized amino acid residue and the distance of the nucleobase from the peptide backbone on the nucleic acid recognition process. It is worth noting that the CD spectroscopy investigation showed that two of the reported nucleopeptides, consisting of alternation of thymine functionalized L-Orn and L-Dab and L-Arg as underivatized amino acids, were able to efficiently bind DNA and RNA targets and cross both cell and nuclear membranes
Application of Severe Weather Nowcasting to Case Studies in Air Traffic Management
Effective and time-efficient aircraft assistance and guidance in severe weather environments
remains a challenge for air traffic control. Air navigation service providers around the globe could
greatly benefit from specific and adapted meteorological information for the controller position,
helping to reduce the increased workload induced by adverse weather. The present work proposes
a radar-based nowcasting algorithm providing compact meteorological information on convective
weather near airports for introduction into the algorithms intended to assist in air-traffic management.
The use of vertically integrated liquid density enables extremely rapid identification and short-term prediction of convective regions that should not be traversed by aircraft, which is an essential
requirement for use in tactical controller support systems. The proposed tracking and nowcasting
method facilitates the anticipation of the meteorological situation around an airport. Nowcasts
of centroid locations of various approaching thunderstorms were compared with corresponding
radar data, and centroid distances between nowcasted and observed storms were computed. The
results were analyzed with Method for the Object-Based Evaluation from the Model Evaluation tools
software (MET-10.0.1, Developmental Testbed Center, Boulder, CO, US) and later integrated into an
assistance arrival manager software, showing the potential of this approach for automatic air traffic
assistance in adverse weather scenarios
Is an NWP-Based Nowcasting System Suitable for Aviation Operations?
The growth of air transport demand expected over the next decades, along with the increasing frequency and intensity of extreme weather events, such as heavy rainfalls and severe storms due to climate change, will pose a tough challenge for air traffic management systems, with implications for flight safety, delays and passengers. In this context, the Satellite-borne and IN-situ Observations to Predict The Initiation of Convection for ATM (SINOPTICA) project has a dual aim, first to investigate if very short-range high-resolution weather forecast, including data assimilation, can improve the predictive capability of these events, and then to understand if such forecasts can be suitable for air traffic management purposes. The intense squall line that affected Malpensa, the major airport by passenger traffic in northern Italy, on 11 May 2019 is selected as a benchmark. Several numerical experiments are performed with a Weather Research and Forecasting (WRF) model using two assimilation techniques, 3D-Var in WRF Data Assimilation (WRFDA) system and a nudging scheme for lightning, in order to improve the forecast accuracy and to evaluate the impact of assimilated different datasets. To evaluate the numerical simulations performance, three different verification approaches, object-based, fuzzy and qualitative, are used. The results suggest that the assimilation of lightning data plays a key role in triggering the convective cells, improving both location and timing. Moreover, the numerical weather prediction (NWP)-based nowcasting system is able to produce reliable forecasts at high spatial and temporal resolution. The timing was found to be suitable for helping Air Traffic Management (ATM) operators to compute alternative landing trajectories
Forecasting the weather to assist ATC and ATM operations
In EUROCONTROLS's recent summary report on Climate Changes Risks for European Aviation, several weather-related impacts were highlighted. There is a strong relation between highly impacting weather events and disruptions to the aviation network resulting in additional fuel consumption and CO2 emissions. In Europe, severe weather is responsible for up to 7.5% of the total en-route delays. In this respect, the H2020 Satellite-borne and IN-situ Observations to Predict The Initiation of Convection for ATM (SINOPTICA) project aims to demonstrate that very high-resolution and very short-range numerical weather forecasts, benefiting from the assimilation of radar data, in-situ weather stations, GNSS and lightning data, can improve the prediction of extreme weather events to the benefit of Air Traffic Management (ATM) and Air Traffic Control (ATC) operations.
The assimilation of radar, GNSS, and lightning data shows a positive impact on the forecast of the convective cells for the four selected severe weather events. Moreover, two radar-based nowcasting strategies, PhaSt and RaNDeVIL, are tested to predict storm structures. Both methods are able to follow the more intense cells (VIL > 10 kg/m2) in all the case studies, as shown by the MODE results and the eye-ball verification The forecasts are used in an arrival management system (AMAN) to compute 4D trajectories around convective areas, integrate the affected aircraft into the arrival sequence, and assist air traffic controllers in implementing the approaches through just in time advisories and dynamic weather displays. With the help of real traffic scenarios and different weather models, diverse approach planning strategies are evaluated
Obesity is a risk factor for acute promyelocytic leukemia: evidence from population and cross-sectional studies and correlation with FLT3 mutations and polyunsaturated fatty acid metabolism.
Obesity correlates with hematologic malignancies including leukemias, but risk of specific leukemia subtypes like acute promyelocytic leukemia and underlying molecular mechanisms are poorly understood. We explored multiple datasets for correlation between leukemia, body mass index (BMI) and molecular features. In a population-based study (n=5.2 million), we correlated BMI with promyelocytic leukemia, and other acute myeloid, lymphoid or other leukemias. In cross-sectional studies, we tested BMI deviation in promyelocytic leukemia trial cohorts from that expected based on national surveys. We explored The Cancer Genome Atlas for transcriptional signatures and mutations enriched in promyelocytic leukemia and/or obesity, and confirmed a correlation between body mass and FLT3 mutations in promyelocytic leukemia cohorts by logistic regression. In the population-based study, hazard ratio per 5 kg/m2 increase was: promyelocytic leukemia 1.44 (95%CI: 1.0-2.08), non-promyelocytic acute myeloid leukemias 1.17 (95%CI: 1.10-1.26), lymphoid leukemias 1.04 (95%CI: 1.0-1.09), other 1.10 (95%CI: 1.04-1.15). In cross-sectional studies, body mass deviated significantly from that expected (Italy: P<0.001; Spain: P=0.011; USA: P<0.001). Promyelocytic leukemia showed upregulation of polyunsaturated fatty acid metabolism genes. Odds of FLT3 mutations were higher in obese acute myeloid leukemias (odds ratio=2.4, P=0.007), whether promyelocytic or not, a correlation confirmed in the pooled promyelocytic leukemia cohorts (OR=1.22, 1.05-1.43 per 5 kg/m2). These results strengthen the evidence for obesity as a bona fide risk factor for myeloid leukemias, and in particular APL. FLT3 mutations and polyunsaturated fatty acid metabolism may play a previously under-appreciated role in obesity-associated leukemogenesis
Divergence of gut permeability and mucosal immune gene expression in two gluten-associated conditions: celiac disease and gluten sensitivity
<p>Abstract</p> <p>Background</p> <p>Celiac disease (CD) is an autoimmune enteropathy triggered by the ingestion of gluten. Gluten-sensitive individuals (GS) cannot tolerate gluten and may develop gastrointestinal symptoms similar to those in CD, but the overall clinical picture is generally less severe and is not accompanied by the concurrence of tissue transglutaminase autoantibodies or autoimmune comorbidities. By studying and comparing mucosal expression of genes associated with intestinal barrier function, as well as innate and adaptive immunity in CD compared with GS, we sought to better understand the similarities and differences between these two gluten-associated disorders.</p> <p>Methods</p> <p>CD, GS and healthy, gluten-tolerant individuals were enrolled in this study. Intestinal permeability was evaluated using a lactulose and mannitol probe, and mucosal biopsy specimens were collected to study the expression of genes involved in barrier function and immunity.</p> <p>Results</p> <p>Unlike CD, GS is not associated with increased intestinal permeability. In fact, this was significantly reduced in GS compared with controls (<it>P </it>= 0.0308), paralleled by significantly increased expression of claudin (CLDN) 4 (<it>P </it>= 0.0286). Relative to controls, adaptive immunity markers interleukin (IL)-6 (<it>P </it>= 0.0124) and IL-21 (<it>P </it>= 0.0572) were expressed at higher levels in CD but not in GS, while expression of the innate immunity marker Toll-like receptor (TLR) 2 was increased in GS but not in CD (<it>P </it>= 0.0295). Finally, expression of the T-regulatory cell marker FOXP3 was significantly reduced in GS relative to controls (<it>P </it>= 0.0325) and CD patients (<it>P </it>= 0.0293).</p> <p>Conclusions</p> <p>This study shows that the two gluten-associated disorders, CD and GS, are different clinical entities, and it contributes to the characterization of GS as a condition associated with prevalent gluten-induced activation of innate, rather than adaptive, immune responses in the absence of detectable changes in mucosal barrier function.</p
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