Ability of 3 Frailty Measures to Predict Short-Term Outcomes in Older Patients Admitted for Post-Acute Inpatient Rehabilitation.

OBJECTIVES To evaluate the ability of 3 commonly used frailty measures to predict short-term clinical outcomes in older patients admitted for post-acute inpatient rehabilitation. DESIGN Observational cohort study. SETTING AND PARTICIPANTS Consecutive patients (n = 207) admitted to a geriatric inpatient rehabilitation facility. METHODS Frailty on admission was assessed using a frailty index, the physical frailty phenotype, and the Clinical Frailty Scale (CFS). Predictive capacity of the frailty instruments was analyzed for (1) nonhome discharge, (2) readmission to acute care, (3) functional decline, and (4) prolonged length of stay, using multivariate logistic regression models and receiver operating characteristic (ROC) curves. RESULTS The number of patients classified as frail was 91 (44.0%) with the frailty index, 134 (64.7%) using the frailty phenotype, and 151 (73.0%) with the CFS. The 3 frailty measures revealed acceptable discriminatory accuracy for nonhome discharge (area under the curve ≥ 0.7) but differed in their predictive ability: the adjusted odds ratio (OR) for nonhome discharge was highest for the CFS [6.2, 95% confidence interval (CI) 1.8-21.1], compared to the frailty index (4.1, 95% CI 2.0-8.4) and the frailty phenotype (OR 2.9, 95% CI 1.2-6.6). For the other outcomes, discriminatory accuracy based on ROC tended to be lower and predictive ability varied according to frailty measure. Readmission to acute care from inpatient rehabilitation was predicted by all instruments, most pronounced by the frailty phenotype (OR 5.4, 95% CI 1.6-18.8) and the frailty index (OR 2.5, 95% CI 1.1-5.6), and less so by the CFS (OR 1.4, 95% CI 0.5-3.8). CONCLUSIONS AND IMPLICATIONS Frailty measures may contribute to improved prediction of outcomes in geriatric inpatient rehabilitation. The choice of the instrument may depend on the individual outcome of interest and the corresponding discriminatory ability of the frailty measure

The high-resolution map of Oxia Planum, Mars; the landing site of the ExoMars Rosalind Franklin rover mission

This 1:30,000 scale geological map describes Oxia Planum, Mars, the landing site for the ExoMars Rosalind Franklin rover mission. The map represents our current understanding of bedrock units and their relationships prior to Rosalind Franklin’s exploration of this location. The map details 15 bedrock units organised into 6 groups and 7 textural and surficial units. The bedrock units were identified using visible and near-infrared remote sensing datasets. The objectives of this map are (i) to identify where the most astrobiologically relevant rocks are likely to be found, (ii) to show where hypotheses about their geological context (within Oxia Planum and in the wider geological history of Mars) can be tested, (iii) to inform both the long-term (hundreds of metres to ∼1 km) and the short-term (tens of metres) activity planning for rover exploration, and (iv) to allow the samples analysed by the rover to be interpreted within their regional geological context

Methane bursts as a trigger for intermittent lake-forming climates on post-Noachian Mars

Lakes existed on Mars later than 3.6 billion years ago, according to sedimentary evidence for deltaic deposition. The observed fluviolacustrine deposits suggest that individual lake-forming climates persisted for at least several thousand years (assuming dilute flow). But the lake watersheds’ little-weathered soils indicate a largely dry climate history, with intermittent runoff events. Here we show that these observational constraints, although inconsistent with many previously proposed triggers for lake-forming climates, are consistent with a methane burst scenario. In this scenario, chaotic transitions in mean obliquity drive latitudinal shifts in temperature and ice loading that destabilize methane clathrate. Using numerical simulations, we find that outgassed methane can build up to atmospheric levels sufficient for lake-forming climates, if methane clathrate initially occupies more than 4% of the total volume in which it is thermodynamically stable. Such occupancy fractions are consistent with methane production by water–rock reactions due to hydrothermal circulation on early Mars. We further estimate that photochemical destruction of atmospheric methane curtails the duration of individual lake-forming climates to less than a million years, consistent with observations. We conclude that methane bursts represent a potential pathway for intermittent excursions to a warm, wet climate state on early Mars

INVESTIGATION OF SEDIMENTARY FAN DEPOSITS ALONG THE BEAGLE GAP TRAVERSE AT JEZERO CRATER, MARS

International audienceIn February 2023, the Perseverance rover ascended the Jezero sedimentary fan deposit that has been interpreted as an ancient river delta (~3.6-3.8 Ga). The ~1.2 km traverse up “Beagle Gap” climbed ~35 m in elevation over 10 sols (martian days). The route passed outcrop exposures up to 20 m higher than had been observed along the delta front drive. Image and compositional data add new information on fan sedimentology and stratigraphy, and indicate a complex history of depositional processes and paleoenvironments.At five mounds along the route, 5-10 m thick, thin-bedded horizontal sandstone strata are present in the uppermost exposures. Locally, conglomerate beds are observed within these strata. This unit is interpreted as fluvial deposits in a delta top environment punctuated by episodic high discharge floods that transported cobble to boulder size clasts. Multiple outcrops of inclined strata are present, although these vary significantly in clast caliber, bedding thickness, and dip direction, which may indicate a range of deposit types. With the diversity in observed sedimentary attributes, a variety of depositional models are being evaluated, including deltaic foresets or lobes, and fluvial deposits.Proximity science using the arm instruments was conducted at one location, “Jenkins Gap.” The poorly sorted, pebbly coarse sandstone has extensive porosity evident in WATSON images. Carbonate composition was identified in the matrix by both arm spectrometers. A candidate lake level (-2490 m) identified in the Kodiak outcrop passes through Jenkins Gap, supporting the interpretation of carbonate formation in a shore-marginal environment. Additionally, this outcrop is texturally similar to lacustrine shoreline ‘tufa’ deposits documented at the Provo level of Pleistocene Lake Bonneville in northeast Utah. Further investigation of the fan stratal geometry through correlation with Beagle Gap units will provide constraints on the relative timing and duration of lakes levels at Jezero crater

PAST VARIATIONS OF WATER LEVEL OF JEZERO PALEOLAKE

International audienceThe western fan of Jezero crater displays features interpreted as fluvial and deltaic sedimentary rocks from orbital data [1,2]. Images obtained using the SuperCam Remote Micro-Imager (RMI) and the Mastcam-Z camera provide in-situ observations of Jezero crater’s western fan in various locations along the Perseverance traverse. In the last two years, the rover analyzed the fan front from a distance using these imaging tools and at close range using its entire payload. Then, in 2023, the Perseverance rover explored the top of the western Jezero sedimentary fan. Here we show that fluvial topsets and deltaic foresets dominate sedimentary rocks. Determining the boundary between fluvial and prodelta deposits enables us to draw the evolution of the lake level through time

PAST VARIATIONS OF WATER LEVEL OF JEZERO PALEOLAKE

International audienceThe western fan of Jezero crater displays features interpreted as fluvial and deltaic sedimentary rocks from orbital data [1,2]. Images obtained using the SuperCam Remote Micro-Imager (RMI) and the Mastcam-Z camera provide in-situ observations of Jezero crater’s western fan in various locations along the Perseverance traverse. In the last two years, the rover analyzed the fan front from a distance using these imaging tools and at close range using its entire payload. Then, in 2023, the Perseverance rover explored the top of the western Jezero sedimentary fan. Here we show that fluvial topsets and deltaic foresets dominate sedimentary rocks. Determining the boundary between fluvial and prodelta deposits enables us to draw the evolution of the lake level through time

SURFACE EXPRESSION AND GEOMETRIES OF DELTAIC DEPOSITS OF JEZERO WESTERN FAN TOP (MARS)

International audienceBetween February-September 2023, the Mars 2020 Perseverance rover explored the upper exposed surface of the western Jezero sedimentary fan. The rover’s exploration focused primarily on the so-called “curvilinear unit.” This unit was initially defined in orbiter images [1, 2] by the presence of repetitive, arcuate decameter-scale bedsets (Fig. 1). These morphologies were first interpreted to be fluvial in origin (likely meanders [2]). However, ground-based inspection from the rover’s perspective tends to show us that they more than likely originate from deltaic depositional processes, in line with other observations made by Perseverance on the fan front [e.g., 3; 4]

PAST VARIATIONS OF WATER LEVEL OF JEZERO PALEOLAKE

International audienceThe western fan of Jezero crater displays features interpreted as fluvial and deltaic sedimentary rocks from orbital data [1,2]. Images obtained using the SuperCam Remote Micro-Imager (RMI) and the Mastcam-Z camera provide in-situ observations of Jezero crater’s western fan in various locations along the Perseverance traverse. In the last two years, the rover analyzed the fan front from a distance using these imaging tools and at close range using its entire payload. Then, in 2023, the Perseverance rover explored the top of the western Jezero sedimentary fan. Here we show that fluvial topsets and deltaic foresets dominate sedimentary rocks. Determining the boundary between fluvial and prodelta deposits enables us to draw the evolution of the lake level through time

SURFACE EXPRESSION AND GEOMETRIES OF DELTAIC DEPOSITS OF JEZERO WESTERN FAN TOP (MARS)

International audienceBetween February-September 2023, the Mars 2020 Perseverance rover explored the upper exposed surface of the western Jezero sedimentary fan. The rover’s exploration focused primarily on the so-called “curvilinear unit.” This unit was initially defined in orbiter images [1, 2] by the presence of repetitive, arcuate decameter-scale bedsets (Fig. 1). These morphologies were first interpreted to be fluvial in origin (likely meanders [2]). However, ground-based inspection from the rover’s perspective tends to show us that they more than likely originate from deltaic depositional processes, in line with other observations made by Perseverance on the fan front [e.g., 3; 4]

SURFACE EXPRESSION AND GEOMETRIES OF DELTAIC DEPOSITS OF JEZERO WESTERN FAN TOP (MARS)

International audienceBetween February-September 2023, the Mars 2020 Perseverance rover explored the upper exposed surface of the western Jezero sedimentary fan. The rover’s exploration focused primarily on the so-called “curvilinear unit.” This unit was initially defined in orbiter images [1, 2] by the presence of repetitive, arcuate decameter-scale bedsets (Fig. 1). These morphologies were first interpreted to be fluvial in origin (likely meanders [2]). However, ground-based inspection from the rover’s perspective tends to show us that they more than likely originate from deltaic depositional processes, in line with other observations made by Perseverance on the fan front [e.g., 3; 4]