322 research outputs found
Synchronous dynamics of zooplankton competitors prevail in temperate lake ecosystems
Although competing species are expected to exhibit compensatory dynamics (negative temporal covariation), empirical work has demonstrated that competitive communities often exhibit synchronous dynamics (positive temporal covariation). This has led to the suggestion that environmental forcing dominates species dynamics; however, synchronous and compensatory dynamics may appear at different length scales and/or at different times, making it challenging to identify their relative importance. We compiled 58 long-term datasets of zooplankton abundance in north-temperate and sub-tropical lakes and used wavelet analysis to quantify general patterns in the times and scales at which synchronous/compensatory dynamics dominated zooplankton communities in different regions and across the entire dataset. Synchronous dynamics were far more prevalent at all scales and times and were ubiquitous at the annual scale. Although we found compensatory dynamics in approximately 14% of all combinations of time period/scale/lake, there were no consistent scales or time periods during which compensatory dynamics were apparent across different regions. Our results suggest that the processes driving compensatory dynamics may be local in their extent, while those generating synchronous dynamics operate at much larger scales. This highlights an important gap in our understanding of the interaction between environmental and biotic forces that structure communities
Early Prediction of Massive Transfusion for Patients With Traumatic Hemorrhage: Development of a Multivariable Machine Learning Model
OBJECTIVE: Develop a novel machine learning (ML) model to rapidly identify trauma patients with severe hemorrhage at risk of early mortality.
BACKGROUND: The critical administration threshold (CAT, 3 or more units of red blood cells in a 60-minute period) indicates severe hemorrhage and predicts mortality, whereas early identification of such patients improves survival.
METHODS: Patients from the PRospective, Observational, Multicenter, Major Trauma Transfusion and Pragmatic, Randomized Optimal Platelet, and Plasma Ratio studies were identified as either CAT+ or CAT-. Candidate variables were separated into 4 tiers based on the anticipated time of availability during the patient\u27s assessment. ML models were created with the stepwise addition of variables and compared with the baseline performance of the assessment of blood consumption (ABC) score for CAT+ prediction using a cross-validated training set and a hold-out validation test set.
RESULTS: Of 1245 PRospective, Observational, Multicenter, Major Trauma Transfusion and 680 Pragmatic, Randomized Optimal Platelet and Plasma Ratio study patients, 1312 were included in this analysis, including 862 CAT+ and 450 CAT-. A CatBoost gradient-boosted decision tree model performed best. Using only variables available prehospital or on initial assessment (Tier 1), the ML model performed superior to the ABC score in predicting CAT+ patients [area under the receiver-operator curve (AUC = 0.71 vs 0.62)]. Model discrimination increased with the addition of Tier 2 (AUC = 0.75), Tier 3 (AUC = 0.77), and Tier 4 (AUC = 0.81) variables.
CONCLUSIONS: A dynamic ML model reliably identified CAT+ trauma patients with data available within minutes of trauma center arrival, and the quality of the prediction improved as more patient-level data became available. Such an approach can optimize the accuracy and timeliness of massive transfusion protocol activation
Moving forward in circles: challenges and opportunities in modelling population cycles
Population cycling is a widespread phenomenon, observed across a multitude of taxa in both laboratory and natural conditions. Historically, the theory associated with population cycles was tightly linked to pairwise consumer–resource interactions and studied via deterministic models, but current empirical and theoretical research reveals a much richer basis for ecological cycles. Stochasticity and seasonality can modulate or create cyclic behaviour in non-intuitive ways, the high-dimensionality in ecological systems can profoundly influence cycling, and so can demographic structure and eco-evolutionary dynamics. An inclusive theory for population cycles, ranging from ecosystem-level to demographic modelling, grounded in observational or experimental data, is therefore necessary to better understand observed cyclical patterns. In turn, by gaining better insight into the drivers of population cycles, we can begin to understand the causes of cycle gain and loss, how biodiversity interacts with population cycling, and how to effectively manage wildly fluctuating populations, all of which are growing domains of ecological research
The Grizzly, March 21, 2000
Bridge Over Troubled Waters: ZX Pledging Activities Leave Fraternity, Two Students Suspended • Memories: Under Construction • Behe Lecture Sparks Scientific Debate • UC Democrats Give Donation to Cityspace • 2000 Edition of Who\u27s Who Announced • Alternative Spring Break: The Best Decision of My Life • The Barto Hotel Jam Night • Lacrosse Prepares for Repeat Title Hopes • Golf Team Looking to Capture CC Title • Softball Off to Commanding Start of Season • Spring is Here, and the UC Bats are Swinging • Baseball Tops Widener in Home Opener, 8-4 • Track & Field Jump Starts Spring Season • Injury-Stricken Gymnasts Pull Out Third at ECAC\u27s • Sports Profile: Taryn Brackinhttps://digitalcommons.ursinus.edu/grizzlynews/1462/thumbnail.jp
The Grizzly, February 22, 2000
Black History Celebrated Across Ursinus Campus • Greeks Fall Under Scrutiny • Arts Program to Expand at UC • Nobel Laureate Lecture Draws Positive Student Response • Littleton, Letterman and the South Carolina Primary • After South Carolina: Can McCain be the Man for the GOP? • Pledging Debate Continues: The Problem of Hazing • Pat McGee: Pseudo DMB? • Valentine\u27s Day Blues • Tumbling and Dancing with Words • Music Review: Dr. John • Glah, Druckenmiller Shine at CC Swimming Championships • UC Wrestling Falls Short in Centennial Championships • UC Spring Sports Preview • Gymnastics Trounces School Record at Marranca Invitational • Men\u27s Basketball Ends Stellar Season • Sports Profile: Christopher Ciuncihttps://digitalcommons.ursinus.edu/grizzlynews/1460/thumbnail.jp
The Grizzly, February 15, 2000
UC Students Debate Pros, Cons of Pledging On Campus • Feelings of Brotherhood, Sisterhood Prevalent During Pledging Process • Employment Available for Graduating Seniors • True Love: Sorrow and Devotion • Hackers, Hijackers, and the Wide World of Sports • The Greeks Agree: Pledges Have no Free Will • Pledging: What\u27s the Big Deal Anyway? • muMs Schemes at Ursinus • Pat McGee to Jam at Ursinus • Music Review: The Alligator Blues Band • Gymnastics Tops RIC with Season High Score • Intramural 3 on 3 Action: Brains vs. Brute • Indoor Track Steps Up to Eight Way Challenge • Ursinus Wrestling Battles for 4-1 • Sports Profile: Shana Goanehttps://digitalcommons.ursinus.edu/grizzlynews/1459/thumbnail.jp
The Grizzly, April 4, 2000
Future Changes in Store for UC • Phi Beta Kappa Speaker Set to Arrive on April 6th • International Round Table Important for Student Input • Mail Boxes, Etc. the Place for all Your Copying Needs • Valedictorian and Salutatorian Announced • Letters to the Editor: Debate Disappointment; Bringing Culture to the Grizzly • Design Versus Darwinism, a New Twist on an Old Debate • Problems With Housing? Maybe it\u27s Something in the Air • Music Review: Jimmy Thackery and the Drivers • Softball Improves to 16-4 • UC Baseball Begins Defense of CC Title • Rocky Start for Ursinus Tennis • UC Lax: Prepared to Take the Challenge • Wrestling with the Books: A Full Pin • CC Honors • UC Tumblers Top Off Season at NCAA Championships • Ursinus Track Tackles Widener • Sports Profile: Matt Wiatrakhttps://digitalcommons.ursinus.edu/grizzlynews/1464/thumbnail.jp
Correction to: The Edinburgh Consensus: preparing for the advent of disease-modifying therapies for Alzheimer's disease.
Since the publication of this article [1], it has come to the attention of the authors that information for one of the authors was not included in the competing interests section. Craig Richie has declared potential competing interests with the following companies; Janssen, Eisai, Pfizer, Eli Lilly, Roche Diagnostics, Boeringher Ingleheim, Novartis, AC Immune, Ixico, Aridhia, Amgen, Berry Consultants, Lundbeck, Sanofi, Quintiles (IQVIA) and Takeda. The full competing interests section for this article can be found below
Digital Twin Mathematical Models Suggest Individualized Hemorrhagic Shock Resuscitation Strategies
BACKGROUND: Optimizing resuscitation to reduce inflammation and organ dysfunction following human trauma-associated hemorrhagic shock is a major clinical hurdle. This is limited by the short duration of pre-clinical studies and the sparsity of early data in the clinical setting.
METHODS: We sought to bridge this gap by linking preclinical data in a porcine model with clinical data from patients from the Prospective, Observational, Multicenter, Major Trauma Transfusion (PROMMTT) study via a three-compartment ordinary differential equation model of inflammation and coagulation.
RESULTS: The mathematical model accurately predicts physiologic, inflammatory, and laboratory measures in both the porcine model and patients, as well as the outcome and time of death in the PROMMTT cohort. Model simulation suggests that resuscitation with plasma and red blood cells outperformed resuscitation with crystalloid or plasma alone, and that earlier plasma resuscitation reduced injury severity and increased survival time.
CONCLUSIONS: This workflow may serve as a translational bridge from pre-clinical to clinical studies in trauma-associated hemorrhagic shock and other complex disease settings
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