449 research outputs found
Spontaneous osteo-dural fistulae of petrous bone posterior wall
SummaryObjectiveTo raise awareness of the possibility of spontaneous temporal bone cerebrospinal fistula in case of clear retrotympanic effusion.Case reportA 63-year-old man with no particular history presented with unilateral spontaneous right retrotympanic clear effusion. CT found defects in the posterior part of the right temporal bone, in contact with arachnoid granulations, with no other visible abnormalities.Discussion/ConclusionUnilateral clear retrotympanic effusion in an adult subject should, apart from serous otitis media, suggest possible cerebrospinal fistula. In the absence of otologic or traumatic history, arachnoid granulation is one possible etiology, inducing spontaneous cerebrospinal fluid leakage when facing the temporal bone. Diagnosis is suggested by bone defects in the tegmen tympani or posterior wall of the temporal bone on CT, with the adjacent mastoid cavities filled with fluid. Pneumococcal vaccination and early surgical repair of the fistula should be performed to avoid neuromeningeal infection
Laboratory Characterisation of a Commercial RGB CMOS Camera for Measuring Night Sky Brightness
The use of RGB cameras in photometric applications has grown over the last few decades in many fields such as industrial applications, light engineering and the analysis of the quality of the night sky. In this last field, they are often used in conjunction with a Sky Quality Meter (SQM), an instrument used for the measurement of night sky brightness (NSB), mainly when there is a significant amount of artificial light at night (ALAN). The performances of these two instruments are compared here. A simple source composed of nine narrowband LEDs in an integrating sphere was used to excite the two instruments and therefore measure the spectral responsivity of the SQM and of the three channels of the camera. The estimated uncertainties regarding spectral responsivity were less than 10%. A synthetic instrument approximating the SQM's responsivity can be created using a combination of the R, G and B channels. The outputs of the two instruments were compared by measuring the spectral radiance of the night sky. An evaluation of the spectral mismatch between the two instruments completed the analysis of their spectral sensitivity. Finally, the measurements of real SQMs in four sites experiencing different levels of light pollution were compared with the values obtained by processing the recorded RGB images. Overall, the analysis shows that the two instruments have significantly different levels of spectral responsivity, and the alignment of their outputs requires the use of a correction which depends on the spectral distribution of the light coming from the sky. A synthetic SQM will always underestimate real SQM measures; an average correction factor was evaluated considering nine sky spectra under low and medium levels of light pollution; this was determined to be 1.11 and, on average, compensated for the gap. A linear correction was also supposed based on the correlation between the NSB levels measured by the two instruments; the mean squared error after the correction was 0.03 mag arcsec-2
Enhancing the teaching-research nexus in the undergraduate curriculum through assessment
Successful linkages between teaching and research in the undergraduate curriculum are strongly dependent on academics’ ability to encourage and facilitate an inquiry based approach to learning. An assessment strategy in which students become active participants in the assessment process is crucial to facilitate the development of this inquiry based approach. Developing this so-called research-mindedness is central to helping students' to become independent learners and to be more effective professionals in their future careers. This paper describes a distributed systems approach to assessment implemented in the undergraduate module Molecular Biology. The assessment comprised a series of sequence identification, database use and analysis steps, with each student being given a different starting gene. In combination, the students analysed an entire genetic pathway. This approach allows the assignments generated to be combined and used to address a single larger question, which can be either teaching or research based. This is then fed back into the teaching. This direct link between the assessment outcomes and the learning process increases student engagement with the subject and sense of ownership of the work carried out. This approach to assessment, in which students undertake a small part of a larger task, is ideal for various technical, skills-based, assignments, such as those central to the many types of bioinformatics analyses. However, it can be adapted to various types of meta-review. The paper discusses the details for the implementation, as well as the benefits and potential pitfalls of the approach
Integration of satellite interferometric data in civil protection strategies for landslide studies at a regional scale
Multi-Temporal Satellite Interferometry (MTInSAR) is gradually evolving from being a tool developed by the scientific community exclusively for research purposes to a real operational technique that can meet the needs of different users involved in geohazard mitigation. This work aims at showing the innovative operational use of satellite radar interferometric products in Civil Protection Authority (CPA) practices for monitoring slow-moving landslides. We present the example of the successful ongoing monitoring system in the Valle D’Aosta Region (VAR-Northern Italy). This system exploits well-combined MTInSAR products and ground-based instruments for landslide management and mitigation strategies over the whole regional territory. Due to the critical intrinsic constraints of MTInSAR data, a robust regional satellite monitoring integrated into CPA practices requires the support of both in situ measurements and remotely sensed systems to guarantee the completeness and reliability of information. The monitoring network comprises three levels of analysis: Knowledge monitoring, Control monitoring, and Emergency monitoring. At the first monitoring level, MTInSAR data are used for the preliminary evaluation of the deformation scenario at a regional scale. At the second monitoring level, MTInSAR products support the prompt detection of trend variations of radar benchmarks displacements with bi-weekly temporal frequency to identify active critical situations where follow-up studies must be carried out. In the third monitoring level, MTInSAR data integrated with ground-based data are exploited to confirm active slow-moving deformations detected by on-site instruments. At this level, MTInSAR data are also used to carry out back analysis that cannot be performed by any other tool. From the example of the Valle D’Aosta Region integrated monitoring network, which is one of the few examples of this kind around Europe, it is evident that MTInSAR provides a great opportunity to improve monitoring capabilities within CPA activities
Dissociation of CH Species on Ni(111):A HREELS Study
The isothermal dissociation rate of CCH and CH on Ni(111) was measured by following, with HREEL spectroscopy, the intensity of the CH stretching peak as a function of time. By repeating the experiment at several different temperatures we obtained an activation energy of 8±3 kcal/mol for the CCH dissociation reaction and of 12±3 kcal/mol for the CH dissociation reaction. Pre-exponential factors were found to be 10^3±1 s-1 in both cases. Independent thermal desorption spectra show a feature at 470 K and a tail extending up to 600 K which can be assigned to the CCH dissociation and the CH dissociation respectively. The two experiments are quantitatively consistent
MRI-DIFFUSION WEIGHTED IMAGING (DWI): A NEW METHOD TO DETECT ACTIVE LUNG INFLAMMATION IN CYSTIC FIBROSIS?
Sky Quality Meter and satellite correlation for night cloud-cover analysis at astronomical sites
The analysis of night cloud cover is very important for astronomical observations in real time, considering a typical observation time of about 15 minutes, and to provide statistics. In this article, we use the Sky Quality Meter (SQM) for high-resolution temporal analysis of the La Silla and Asiago (Ekar Observatory) sky: 3 and 5 minutes respectively. We investigate the annual temporal evolution of the natural contributions of the sky at a site not influenced by artificial light at night (ALAN) and at one highly influenced. We also make a correlation between GOES and Aqua satellite data and ground-based SQM data to confirm the relationship between the SQM data and cloud cover. We develop an algorithm that allows the use of the SQM for night cloud detection and reach correlations with the nighttime cloud cover detected by the GOES and Aqua satellites of 97.2 per cent at La Silla and 94.6 per cent at Asiago. Our algorithm also classifies photometric (PN) and spectroscopic nights (SN). We measure 59.1 per cent PN and 21.7 per cent SN for a total percentage of clear nights of 80.8 per cent at La Silla in 2018. The respective Ekar Observatory values are 31.1 per cent PN, 24.0 per cent SN and 55.1 per cent of total clear night time. Application to the SQM network would involve the development of long-term statistics and large data forecasting models for site testing and real-time astronomical observation
Combination of ozone and activated carbon for Pharmaceuticals and Personal Care Products (PPCPs) removal in drinking water: influence of compounds characteristics and organic matter competition
The presence of Pharmaceuticals and Personal Care Products (PPCPs) in drinking water is raising concern for potential negative effects on human health. Ozonation and adsorption on activated carbon (AC) are the most promising processes for PPCPs removal among those usually present in drinking water treatment plants (DWTPs). To evaluate the performance of these processes, both individually and in combination, adsorption isotherms were determined on real matrices collected in a DWTP before and after ozonation, focusing on 10 PPCPs identified as the most critical for the analysed DWTP. AC showed higher PPCPs removals than ozonation, but the combination of the two processes was beneficial. However, the effect of ozone on adsorption depends on PPCPs reactivity with ozone. A competitive effect of organic matter on PPCPs adsorption was observed. Finally, the removal of absorbance at 254 nm is a good proxy variable for PPCPs removal
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