Identifying Factors Predicting Kidney Graft Survival in Chile Using Elastic-Net-Regularized Cox's Regression.

: We developed a predictive statistical model to identify donor-recipient characteristics related to kidney graft survival in the Chilean population. Given the large number of potential predictors relative to the sample size, we implemented an automated variable selection mechanism that could be revised in future studies as more national data is collected. : A retrospective multicenter study was conducted to analyze data from 822 adult kidney transplant recipients from adult donors between 1998 and 2018.

Replacing quarantine of COVID-19 contacts with periodic testing is also effective in mitigating the risk of transmission.

The quarantine of identified close contacts has been vital to reducing transmission rates and averting secondary infection risk before symptom onset and by asymptomatic cases. The effectiveness of this contact tracing strategy to mitigate transmission is sensitive to the adherence to quarantines, which may be lower for longer quarantine periods or in vaccinated populations (where perceptions of risk are reduced). This study develops a simulation model to evaluate contact tracing strategies based on the sequential testing of identified contacts after exposure as an alternative to quarantines, in which contacts are isolated only after confirmation by a positive test.

Grid-wide assessment of varying re-regulation storage capacity for hydropeaking mitigation.

Hydropeaking affects downstream ecosystems and water uses. We assessed the effect of small re-regulation reservoirs (RRR) located downstream of hydropower plants to mitigate the impact of hydropeaking operations, in terms of the tradeoffs between flashiness of flows and power system cost. The study is performed on a hypothetical power system composed by one reservoir hydropower plant, one coal-fired plant, one diesel-fired plant, and one wind power plant.

Ordering sequential competitions to reduce order relevance: Soccer penalty shootouts.

In sequential competitions, the order in which teams take turns may have an impact on performance and the outcome. Previous studies with penalty shootouts have shown mixed evidence of a possible advantage for the first shooting team. This has led to some debate on whether a change in the rules of the game is needed.

Assessing the effect of fish size on species distribution model performance in southern Chilean rivers.

Despite its theoretical relationship, the effect of body size on the performance of species distribution models (SDM) has only been assessed in a few studies, and to date, the evidence shows unclear results. In this context, Chilean fishes provide an ideal case to evaluate this relationship due to their short size (fishes between 5 cm and 40 cm) and conservation status, providing evidence for species at the lower end of the worldwide fish size distribution and representing a relevant management tool for species conservation. We assessed the effect of body size on the performance of SDM in nine Chilean river fishes, considering the number of records, performance metrics, and predictor importance.

Association Among ICU Congestion, ICU Admission Decision, and Patient Outcomes.

Objectives: To employ automated bed data to examine whether ICU occupancy influences ICU admission decisions and patient outcomes.

Design: Retrospective study using an instrumental variable to remove biases from unobserved differences in illness severity for patients admitted to ICU.

Setting: Fifteen hospitals in an integrated healthcare delivery system in California.