102. Evaluation of the Association between the Antibiotic Spectrum Index and Antibiotic Days of Therapy: A Retrospective Study across 124 Acute-care Hospitals

Background Antibiotic stewardship programs often measure antibiotic days of therapy (DOT), but this metric does not reflect the antibiotic spectrum. In this study, we used the previously published Antibiotic Spectrum Index (ASI), which attaches a score (1-13) to the spectrum of each antibiotic, to evaluate the content of antibiotic use across all Veterans Health Administration (VHA) hospitals. We also assessed how benchmarking hospital performance changed when ASI was used instead of DOT. Methods We conducted a retrospective cohort study of patients admitted to 124 acute-care VHA hospitals during 2018. We obtained data on administered antibiotics, the days of antibiotic use (DOT), and days-present (DP) from the VHA Corporate Data Warehouse and then aggregated data to the hospital-level using the National Healthcare Safety Network’s methodology. We modified the original ASI by changing 3.8% of the bug-drug scores to ensure consistency across all scores and adding 27 new antibiotics agents. For each hospital, we calculated ASI/DOT, ASI/1,000 DP, and DOT/1,000 DP and ranked hospitals on their performance. We performed a Spearman’s rank-order correlation to compare hospitals on these metrics and their associated rankings. Results At the hospital-level, the median ASI/DOT, ASI/1,000 DP and DOT/1,000 DP were 5.4 (interquartile range: 5.2-5.8), 2,332.7 (1,941.8-2,796.2) and 443.5 (362.5-512.2), respectively. There was a strong correlation between the ASI/1,000 DP and DOT/1,000 DP metrics [Spearman’s correlation test: r=0.97 (p< 0.01)] but only a weak and insignificant correlation between ASI/DOT and DOT/1,000 DP [r=0.17 (p=0.06), Figure 1]. Twenty (16.1%) hospitals showed a difference of 10% or more in their ranking for ASI/1,000 DP compared to their ranking for DOT/1,000 DP. The range of ranking difference was from -17.7% to 21.0% (Figure 2a and b). Figure 1. Distribution of the Antibiotic Spectrum Index / Day of Therapy by Days of Therapy / 1000 Days Present for 124 Acute-Care VHA Hospitals during 2018. Black line: Median values of DOT/1,000 DP and ASI/DOT, respectively. Figure 2. (a) Distribution of the rankings in DOT/1,000 DP and ASI/1,000 DP. Blue line: the position of same ranking between ASI/1,000 DP and DOT/1,000 DP. (b) Distribution of the differences in each hospital’s ranking for DOT/1,000 DP and ASI/1,000 DP Conclusion Our findings suggest that hospitals using fewer days of antibiotic therapy did not necessarily use narrower-spectrum antibiotics. ASI/1,000 DP, as a combined measure of antibiotic consumption quantity and average spectrum, provided a different view of hospital performance than DOT/1,000 DP alone. Future work is needed to define how this new metric relates to the quality of antibiotic use. Disclosures All Authors: No reported disclosures

Investigation of Radio Frequency Licensed Spectrum Utilization in Nigeria: A Study of Rumuokwuta, Port Harcourt, Nigeria

This study was carried out to investigate the spectrum utilization of the licensed Radio Frequency (RF) spectrum in Rumuokwuta, Port Harcourt. An outdoor measurement of spectrum occupancy was carried out in a high-rise building situated at Rumuokwuta urban area in Port Harcourt, Nigeria using RF explorer spectrum analyzer and a personal computer laptop system. Spectrum activities in the band of 240-960 MHz were monitored for 24 hours. The frequency band was subdivided into 24 sub bands each with a span size of 30 MHz. Scanning of bands was made efficient using a python script that scans a range, analyzed the frequencies and signal strengths for 112 data points, saves data in CSV file format, scans the next range until the 24 ranges were scanned. The process was repeated to achieve 15 iterations. With a noise floor of - 110dBm, a threshold of -95dBm was used to determine the presence of signal, hence the spectrum occupancy of measured bands. Results showed that out of the 24 investigated sub bands; only one band was completely occupied with spectrum occupancy of 100%. 12 bands were partially occupied while 11 were completely free. The average spectrum occupancy for the whole band was obtained as 11.64%. This showed good location for dynamic spectrum access and cognitive radio deployment, especially in Television White Space (TVWS).

Calibration Technique for Suppressing Residual Etalon Artifacts in Slit-Averaged Raman Spectroscopy

Back-illuminated charged-coupled device (BI-CCD) arrays increase quantum efficiency but also amplify etaloning, a multiplicative, wavelength-dependent fixed-pattern effect. When spectral data from hundreds of BI-CCD rows are combined, the averaged spectrum will generally appear etalon-free. This can mask substantial etaloning at the row level, even if the BI-CCD has been treated to suppress the effect. This paper compares two methods of etalon correction, one with simple averaging and one with row-by-row calibration using a fluorescence standard. Two BI-CCD arrays, both roughened by the supplier to reduce etaloning, were used to acquire Raman spectra of murine bone specimens. For one array, etaloning was the dominant source of noise under the exposure conditions chosen, even for the averaged spectrum across all rows; near-infrared-excited Raman peaks were noticeably affected. In this case, row-by-row calibration improved the spectral quality of the average spectrum. The other CCD’s performance was shot-noise limited and therefore received no benefit from the extra calibration. The different results highlight the importance of checking for and correcting row-level fixed pattern when measuring weak Raman signals in the presence of a large fluorescence background.

Widely distributed exogenic materials of varying compositions and morphologies on asteroid (101955) Bennu

Using the multiband imager MapCam onboard the OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer) spacecraft, we identified 77 instances of proposed exogenic materials distributed globally on the surface of the B-type asteroid (101955) Bennu. We identified materials as exogenic on the basis of an absorption near 1 µm that is indicative of anhydrous silicates. The exogenic materials are spatially resolved by the telescopic camera PolyCam. All such materials are brighter than their surroundings, and they are expressed in a variety of morphologies: homogeneous, breccia-like, inclusion-like, and others. Inclusion-like features are the most common. Visible spectrophotometry was obtained for 46 of the 77 locations from MapCam images. Principal component analysis indicates at least two trends: (i) mixing of Bennu's average spectrum with a strong 1-µm band absorption, possibly from pyroxene-rich material, and (ii) mixing with a weak 1-µm band absorption. The endmember with a strong 1-µm feature is consistent with Howardite-Eucrite-Diogenite (HED) meteorites, whereas the one showing a weak 1-µm feature may be consistent with HEDs, ordinary chondrites, or carbonaceous chondrites. The variation in the few available near-infrared reflectance spectra strongly suggests varying compositions among the exogenic materials. Thus, Bennu might record the remnants of multiple impacts with different compositions to its parent body, which could have happened in the very early history of the Solar System. Moreover, at least one of the exogenic objects is compositionally different from the exogenic materials found on the similar asteroid (162173) Ryugu, and they suggest different impact tracks.

Comparative perceptual evaluation and acoustic voice analysis of a transgender client male to female before and after laser-assisted voice adjustment surgery

In this study, we examined changes in the voice quality of a transgender client who had previously undergone male-to-female (MtF) transition. We conducted a longitudinal phonetic analysis after obtaining recordings from our client before and after undergoing laser-assisted voice adjustment (LAVA) surgery. The following acoustic parameters were compared: fundamental frequency (F0) measures, local jitter, shimmer, harmonic to noise ratio, phonation time, and long-term average spectrum. We assumed that the voice would not change significantly as a result of previous hormonal and vocal therapy, and that its timbre would be closer to female values after LAVA surgery. Since the client was on hormone therapy before the surgery, the average values of F0 corresponded to the values of a normal female voice (190.1 Hz), and, after surgery, the voice became significantly higher in phonation (235.6 Hz). Before surgery, the voice was high for a male voice during reading (mean F0 = 150.19 Hz for non-fricative text (NT) and mean F0 = 158.06 Hz for fricative text (FT)). After surgery, the voice exhibited higher F0 values (F0 = 184.72 Hz for NT and F0 = 191.87 Hz for FT). Before surgery, the voice was average high for a male voice during spontaneous speech (F0 = 119.90 Hz), while after surgery the F0 was 161.33 Hz during spontaneous speech, which is somewhat lower than the average pitch values of the female voice, but its timbral quality is more feminine. Since spontaneous speech is very important for comparison vocal timbre, we can conclude that the 42 Hz difference observed is notable. Although the minimal and maximal values of F0 based on phonation were significantly higher after surgery (p < 0.001), the range was limited. The total results of the F0 measures are higher than expected, while the shortened phonation time points to the need for voice therapy. Considering all our results, we can conclude that it is important to discuss a client’s profession before considering LAVA surgery.

Mineralogical composition of terrestrial feldspathic rocks using reflectance spectroscopy data from HySpex hyperspectral cameras

&lt;p&gt;New feldspar detections made by visible-near infrared (VNIR) spectroscopy last year on Mars [1], raise questions on the nature of the rocks involved and the magmatic processes responsible for their formation.&lt;/p&gt;&lt;p&gt;Following these new findings, a range of terrestrial feldspathic rocks, which are possible analogs to the feldspar-bearing Martian rocks, were analyzed using a VNIR point-spectrometer (ASD Fieldspec 4) in a laboratory [2]. A spectral library referencing the average reflectance spectrum of uncrushed terrestrial feldspathic rocks, including granites, granodiorites, phenocryst basalts, dacites, anorthosites, was assembled. One of the conclusions from this work was that a more detailed, grain-by-grain spectral analysis is needed.&lt;/p&gt;&lt;p&gt;In this study we used a new instrument that made it possible to determine the grain-by-grain mineralogical composition of these same terrestrial analog rocks. VNIR spectra were acquired with the HySpex hyperspectral cameras VNIR-1800 and SWIR-384 that acquire high-resolution data in the visible near-infrared and short-wave infrared wavelength ranges. The cameras image the scene line by line using the pushbroom scanning technique. Using interchangeable lenses, cameras were used to acquire spectroscopy data at a distance of 30cm and at 8cm from the sample. In the VNIR, this results in a pixel size of about 53 &amp;#181;m and 24&amp;#181;m at sample-sensor distance of 30cm and 8cm, respectively, while in the SWIR, the pixel size is 250 &amp;#181;m and 55&amp;#181;m at a distance of at 30cm and 8cm, respectively. The hyperspectral cubes are analyzed with the ENVI software to classify the image pixels according to their spectral signature.&amp;#160;Thus, the different minerals present in the rock, which are often on a millimeter scale, are grouped into different classes.&amp;#160;The statistics give the average spectrum of each class, and therefore each mineral group.&lt;/p&gt;&lt;p&gt;This study, complementary to that of &lt;em&gt;Barthez et al. &lt;/em&gt;(2020), makes it possible to associate, for each studied rock sample, an average reflectance spectrum of the bulk rock to a precise mapping of the different minerals present in the rock. This study allows us to determine if the feldspar minerals are contributing to the observed rock spectrum, and to assess each mineral group&amp;#8217;s contribution to the spectral signature of the whole rock. Detailed petrographic characterization of rocks are also being conducted to evaluate characterizations done with spectral data.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;References&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;[1] J.Flahaut et al. (2020). EGU Abstracts, EGU2020-13377&lt;/p&gt;&lt;p&gt;[2] M.Barthez et al. (2020). EPSC Abstracts, EPSC2020-606&lt;/p&gt;

Energetic particles and radar blackouts at Mars

&lt;p&gt;We present the first long-term characterization of the lower ionosphere of Mars, a region previously inaccessible to orbital observations, based on an analysis of radar echo blackouts observed by MARSIS on Mars Express and SHARAD on the Mars Reconnaissance Orbiter from 2006 to 2017.&amp;#160; A blackout occurs when the expected surface reflection is partly to fully attenuated for portions of an observation.&amp;#160; Enhanced ionization at altitudes of 60 to 90 km, below the main ionospheric electron density peak, results in the absorption of the radar signal, leading to a radar blackout.&amp;#160; MARSIS, operating at frequencies between 1.8 and 5 MHz suffered more blackouts than SHARAD, which has a higher carrier frequency (20 MHz).&amp;#160; More events are seen during solar maximum while&amp;#160; there is no apparent relationship between blackout occurrence and crustal magnetic fields. Blackouts do occur during both nightside and dayside observations, and have an interesting variation with solar zenith angle.&amp;#160; &amp;#160;Analysis of MAVEN Solar Energetic Particle (SEP) electron counts between 20 and 200 keV during selected events demonstrates that these electrons are responsible for such events, and we investigate the minimum SEP electron fluxes required to ionize the lower atmosphere and produce &amp;#160;measurable attenuation.&amp;#160; When both radars observe a radar blackout at the same time, the SEP electron fluxes are at their highest. For certain events, we find that the average spectrum responsible for a blackout is particularly enhanced at the higher energy end of the spectrum, i.e. above 70 keV .&amp;#160; &amp;#160;This study is, therefore, important for future communications for human exploration of Mars.&lt;/p&gt;