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A lidar model of asteroid (101955) Bennu has a north-south asymmetry in shape and evidence of an early partial disruption., We investigate the shape of near-Earth asteroid (101955) Bennu by constructing a high-resolution (20 cm) global digital terrain model from laser altimeter data. By modeling the northern and southern hemispheres separately, we find that longitudinal ridges previously identified in the north extend into the south but are obscured there by surface material. In the south, more numerous large boulders effectively retain surface materials and imply a higher average strength at depth to support them. The north has fewer large boulders and more evidence of boulder dynamics (toppling and downslope movement) and surface flow. These factors result in Bennu’s southern hemisphere being rounder and smoother, whereas its northern hemisphere has higher slopes and a less regular shape. We infer an originally asymmetric distribution of large boulders followed by a partial disruption, leading to wedge formation in Bennu’s history.

The Canadian Space Agency (CSA) has contributed to the Origins Spectral Interpretation Resource Identification Security-Regolith Explorer (OSIRIS-REx) spacecraft the OSIRIS-REx Laser Altimeter (OLA). The OSIRIS-REx mission will sample asteroid 101955 Bennu, the first B-type asteroid to be visited by a spacecraft. Bennu is thought to be primitive, carbonaceous, and spectrally most closely related to CI and/or CM meteorites. As a scanning laser altimeter, the OLA instrument will measure the range between the OSIRIS-REx spacecraft and the surface of Bennu to produce digital terrain maps of unprecedented spatial scales for a planetary mission. The digital terrain maps produced will measure $\sim7~\mbox{cm}$ per pixel globally, and $\sim3~\mbox{cm}$ per pixel at specific sample sites. In addition, OLA data will be used to constrain and refine the spacecraft trajectories. Global maps and highly accurate spacecraft trajectory estimates are critical to infer the internal structure of the asteroid. The global and regional maps also are key to gain new insights into the surface processes acting across Bennu, which inform the selection of the OSIRIS-REx sample site. These, in turn, are essential for understanding the provenance of the regolith sample collected by the OSIRIS-REx spacecraft. The OLA data also are important for quantifying any hazards near the selected OSIRIS-REx sample site and for evaluating the range of tilts at the sampling site for comparison against the capabilities of the sample acquisition device.

Background: Delirium has a high incidence pathology associated with negative outcomes. Although highly preventable, half the cases are not recognized. One major cause of delirium misdiagnosis is the absence of a versatile instrument to measure it. Aims: Our objective was to translate the nursing delirium screening scale (Nu-DESC) and evaluate its performance in Italian settings. Methods: This was a methodological study conducted in two sequential phases. The first was the Italian translation of Nu-DESC through a translation and back-translation process. The second aimed to test the inter-rater reliability, the sensibility and specificity of the instrument on a convenience sample of 101 hospitalized elderly people admitted to relevant wards of the San Gerardo Hospital in Monza. To evaluate the inter-rater reliability, two examiners tested Nu-DESC on 20 patients concurrently without comparison. To measure the sensibility and specificity of Nu-DESC, the confusion assessment method was used as a gold standard measure. Results: The inter-rater reliability (Cohen Kappa) was 0.87—an excellent agreement between examiners. The study of the ROC curve showed an AUC value of 0.9461 suggesting high test accuracy. Using 3 as a cut-off value, Nu-DESC showed 100 % sensibility and 76 % specificity. Discussion and conclusion: Further research is needed to test Nu-DESC on a larger sample. However, based on our results, Nu-DESC can be used in research and clinical practice in Italian settings because of its very good and similar performances to previous validation studies. The value of 3 appears to be the optimal cut-off in the Italian context.

While the two solitudes of our title, computerized control and telecommunications, are both concerned with computerized solutions to real world problems, we suggest that they are really addressing different needs and are therefore naturally preoccupied by slightly different concerns. We present a taxonomy of key elements intended to make such differences explicit in order to promote more mutual understanding and more collaborative work where concerns are shared. In particular, we suggest that one key difference lies in the nature of the timing requirements associated with reactivity, and whether they are considered as extensions to logical correctness or performance.