Journals
2025 EN
Terauds Aleks · Lee Jasmine R. · Wauchope Hannah S.
+9 more
Abstract Antarctica is one of Earth's most untouched, inhospitable, and poorly known regions. Although knowledge of its biodiversity has increased over recent decades, a diverse, wide‐ranging, and spatially explicit compilation of the biodiversity that inhabits Antarctica's permanently ice‐free areas is unavailable. This absence hinders both Antarctic biodiversity research and the integration of Antarctica in global biodiversity–related studies. Fundamental and applied research on biodiversity patterns, ecological structure and function, and options for conservation are reliant on spatially resolved, taxonomically consistent observations. Such information is especially important for modern, data‐driven biodiversity science, in both Antarctica and globally, and forms the backbone of biodiversity informatics, reflected, for example, in the Darwin Core Standard used by the Global Biodiversity Information Facility. Biodiversity data are also essential to fulfill the conservation requirements for Antarctica, as set out in the Protocol on Environmental Protection to the Antarctic Treaty and inform the design of systematic surveys to address biodiversity and ecological knowledge gaps, for both specific taxa and ecosystems. Such surveys are key requirements for understanding and mitigating the impacts of environmental change on the region's biodiversity. Here, we address these requirements through the public release of The Biodiversity of Ice‐free Antarctica Database. In 2008, we extracted a subset of biodiversity records only from terrestrial ice‐free areas from the Scientific Committee on Antarctic Research (SCAR) Antarctic Biodiversity Database. We have subsequently added thousands of records from a range of sources: checking, and where necessary (and possible), correcting the spatial location, clarifying, cross‐referencing, and harmonizing taxonomy with globally recognized sources, and documenting the original source of records. The Biodiversity of Ice‐free Antarctica Database spans the early 1800s to 2019 (with most records collected after 1950) and represents the most comprehensive consolidation of Antarctic ice‐free biodiversity occurrence data yet compiled into a single database. The Biodiversity of Ice‐free Antarctica Database contains 35,654 records of 1890 species in over 800 genera across six kingdoms and spans all Antarctic Conservation Biogeographic Regions. These data are released under a CC BY Attribution License ( http://creativecommons.org/licenses/by/4.0/ ).
Journals
2025 EN
Jiang Renping · Liu Wenwen · Pennings Steven C.
Abstract Adjusting relative allocation between sexual and clonal reproduction is part of how plants respond to a variable environment, but we know little about how the allocation strategies of plant populations vary over time as abiotic conditions change. We studied correlations between sexual and clonal reproduction using 23 years of data on the clonal salt marsh plant Spartina alterniflora at eight sites in coastal Georgia, USA. The relationship between sexual reproduction and clonal reproduction varied over time. Within years, sexual reproduction was negatively related to clonal reproduction. These relationships were stronger in cooler years and weaker in warmer years, with slopes ranging from −0.202 in cool years to −0.013 in warm years. The trade‐offs were also affected by river discharge, with stronger (more negative) slopes as river discharge increased. In a random forest model, temperature had the greatest influence (58%) on the relationships compared to other global change variables (precipitation, river discharge, sea level, and tide range). Overall, our study demonstrated that climate warming gradually disrupts the negative correlation in allocation between reproductive modes in a common salt marsh plant, shifting the affected populations toward a near‐total reliance on clonal reproduction, potentially limiting their spread and the generation of new genotypes.
Journals
2025 EN
Miller Amy E. · Csank Adam Z. · Hannam Michael P.
+2 more
Abstract Late 20th century warming has weakened the relationship between temperature and growth in northern forests. This loss of sensitivity to temperature, often attributed to drought stress in warmer regions of the boreal forest, has also been observed in cool, mesic environments, where warming‐related growth declines are poorly understood. We used annually resolved ring‐width and carbon stable isotope (δ 13 C) chronologies from white spruce forest and woodland stands in southwest Alaska to examine tree responses to climate during a recent warming period (1970–2011). Trends in ring‐width index (RWI) varied by stand type: RWI increased in forests and woodlands in the first half of the record (1970–1990), but only woodlands continued that trend in the latter half (1991–2011). Warmer spring temperatures predicted increased RWI in both stand types, and warmer summer temperatures predicted decreased RWI in forests, but these relationships weakened through time. Carbon isotope discrimination (Δ 13 C), a frequent indicator of stomatal regulation of water loss, showed no coherent trend in either stand type but was positively associated with summer precipitation in forests, suggesting the potential for intermittent water limitation. Our results indicate that RWI and Δ 13 C have responded differently to climate through time and that these responses have been mediated by stand type.
Journals
2025 EN
Butler Mark J. · McMurray Steven E. · Pawlik Joseph R.
Abstract A recurrent theme in marine ecology is that the community dynamics of sessile, suspension‐feeding animals is primarily limited by the availability of space, but in some habitats, filtration by these organisms may locally deplete water column resources, setting the stage for exploitative competition for food. We examined filtration by sponge assemblages in the shallow waters (~2 m depth) of Florida Bay (Florida, USA), where water residence times are often high and filtration by dense communities of sponges was hypothesized to deplete the water column of food, primarily picoplankton and dissolved organic matter (DOM). We transplanted three sponge species into replicate locations that differed by an order of magnitude in natural sponge community biomass. Sponge transplants were clones, enabling us to control for sponge genotype effects across all sites. The growth of sponge clones was recorded seasonally for 18–30 months. Growth of transplants placed in areas devoid of sponges was 10 times greater than growth in areas with dense sponge communities and three times greater than growth in areas with average sponge biomass. Sponge mortality was similar regardless of background sponge density. Measurements of picoplankton, DOM, and PO 4 concentration confirmed an inverse relationship with sponge community biomass, whereas nitrogen concentrations in seawater were highest where sponge species replete with nitrogen‐fixing symbiotic microbial communities were most abundant. This is striking evidence that filtration of waterborne resources by sponges in shallow, coastal environments can deplete those resources sufficiently to cause exploitative competition that limits sponge growth.
Journals
2025 EN
Ortega Nicole · Shepack Alexander · Price Wayne
+4 more
Abstract The emergence of infectious diseases is often associated with changes to host–pathogen ecology, and wildfires are known to profoundly modify the ecology of terrestrial and freshwater ecosystems. Nevertheless, few studies have employed manipulative experiments to quantify the effects of fire on infections across parasite species. In a mark–recapture study, prescribed burns did not significantly affect the densities of Cuban tree frog (CTF; Osteopilus septentrionalis ) definitive hosts. However, prescribed burn field experiments and a before‐after‐control‐burn mesocosm study revealed that fire decreased a skin‐penetrating nematode in CTFs by killing the parasite's soil‐dwelling, free‐living stage, with hotter fires causing a greater reduction in soil‐dwelling nematodes. Additionally, prescribed burns were associated with increases in a terrestrial acuariid nematode and several aquatic trematode metacercariae in CTFs, likely by increasing intermediate host densities. Seven years after the burns, we found little evidence of full recovery because the trajectories of these parasites did not show clear signs of flattening. These results suggest that fire can have predictable and long‐term direct and indirect positive and negative effects on parasite transmission.
Journals
2025 EN
Hiatt Drew · Dillon Whalen W. · Gardner Allison
+4 more
Abstract Plant invasions may alter disease vector abundance by several mechanistic pathways, including modifying microclimates that influence vector survival or changing habitats to influence host use. Here, we used a field experiment and observational data to evaluate multiple mechanistic pathways (tick survival and host abundance) by which plant invasions may alter vector‐borne disease risk using the common disease vector lone star tick ( Amblyomma americanum ), its preeminent host white‐tailed deer ( Odocoileus virginianus ), and the widespread invasive cogongrass ( Imperata cylindrica ) in the southeastern United States. In the field experiment, ticks survived over 50% longer in areas dominated by the invasive plant compared to those with only native plant species. Invaded areas had lower temperatures and higher relative humidity, yielding a lower vapor pressure deficit (VPD) that likely reduced tick desiccation. The observational study showed similar average tick abundance in native and invaded plant communities and no difference in wildlife host (white‐tailed deer) activity between plant communities. However, there was a positive relationship between tick abundance and white‐tailed deer activity, but only in native areas. Together, these results suggest that more favorable microclimate conditions resulting in greater tick longevity are the dominant driver of tick abundance in invaded areas, while tick abundance in native‐dominated areas may be promoted, at least in part, by white‐tailed deer activity. Our results demonstrate that plant invasions can affect multiple, potentially counteracting mechanistic pathways that contribute to tick exposure risk. The complexity of these relationships highlights the need for a better understanding of how invasive species and other global change drivers influence disease vectors and, ultimately, disease transmission.
Journals
2025 EN
Raza Hassan · Cheng Junye · Kandasamy Subash
+8 more
High‐entropy oxides (HEOs) have sparked scientific interest recently as a potential material technology for lithium‐sulfur (Li–S) batteries. This interest stems from their simultaneous roles as sulfur hosts and electrocatalysts, which provide enhancements to the performance of sulfur cathode composites. Nonetheless, their incorporation into the active material blend results in compromised energy density, particularly when their gravimetric proportion is substantial (≥10 wt.%, in the sulfur‐based cathode). In this study, a manganese (Mn)‐containing HEO (S config ≥ 1.5R) was synthesized and subsequently coated onto a commercial Celgard separator at a low areal loading (~0.23 mg cm −2 ) with the aim of decreasing HEO content in the cathode composite material while still boosting lithium polysulfide (LPS) conversion kinetics. Li–S batteries incorporating this modified separator‐high entropy oxide (MS‐HEO) demonstrate exceptional electrochemical performance, achieving a high initial discharge capacity of ~1642 mAh g −1 at 0.1 C and a remarkably low‐capacity fade rate of 0.055% per cycle over 450 cycles at 1 C. Remarkably, the MS‐HEO batteries exhibited commendable electrochemical performance at high sulfur loading (~7 mg cm −2 ), delivering an initial discharge capacity of ~819 mAh g −1 during the first discharge and maintaining stable cycling up to 30 cycles at 0.1 C thereafter. Collectively, this work underscores the significance of precise adjustment of HEO compositions through low‐temperature MOF calcination strategies and demonstrates their potential to enhance the electrochemical performance of Li–S batteries under the high‐sulfur loading conditions necessary for future commercial applications.
Journals
2025 EN
Biegus Jan · Mebazaa Alexander · Metra Marco
+16 more
Abstract Aims Cardiogenic shock (CS) is linked to high morbidity and mortality rates, posing a challenge for clinicians. Interventions to improve tissue perfusion and blood pressure are crucial to prevent further deterioration. Unfortunately, current inotropes, which act through adrenergic receptor stimulation, are associated with malignant arrhythmias and poorer outcomes. Due to its unique mechanism of action, istaroxime should improve haemodynamics without adrenergic overactivation. The SEISMiC study is designed to examine the safety and efficacy (haemodynamic effect) of istaroxime administrated in pre‐CS patients. Methods and Results The SEISMiC study is a multinational, multicentre, randomized, double‐blind, placebo‐controlled safety and efficacy study with two parts (A and B). The study enrols patients hospitalized for decompensated heart failure (pre‐CS, not related to myocardial ischaemia) with persistent hypotension [systolic blood pressure (SBP) 70–100 mmHg for at least 2 h] and clinically confirmed congestion, NT‐proBNP ≥1400 pg/mL, and LVEF≤40%. Subjects must not have taken intravenous (iv) vasopressors, inotropes or digoxin in the past 6 h. Eligible patients are randomized to receive IV infusion of istaroxime (different doses and regimens in Parts A and B) or placebo for up to 60 h. Central haemodynamics, ECG Holter monitoring, cardiac ultrasound and biomarkers are recorded at predefined time points during the trial. The study's primary efficacy endpoint is the SBP area under the curve from baseline curve from baseline to 6 and 24 h in the combined SEISMiC Parts A and B population. Key secondary efficacy endpoints include haemodynamic, laboratory and clinical measures in SEISMiC B alone in the combined SEISMiC A and B studies. Conclusions The study results will contribute to our understanding of the role of istaroxime in pre‐CS patients and potentially provide insight into the drug's haemodynamic effects and safety in this population.
Journals
2025 EN
Alonso Windy W. · Bills Sara E. · Lundgren Scott W.
+8 more
Abstract Aims Most adults with stable heart failure are safe to exercise at a moderate intensity for 150 min/week. Regular participation in exercise may improve outcomes in adults with heart failure with preserved ejection fraction (HFpEF). Few adults with HFpEF initiate and sustain long‐term exercise. To promote exercise adherence in adults with HFpEF, we developed the Heart Failure Exercise and Resistance Training (HEART) Camp Connect intervention that is tested in this clinical trial. This trial tests our central hypothesis that theory‐informed coaching strategies delivered virtually will promote long‐term adherence to exercise in adults with HFpEF and drive clinically meaningful, and cost‐effective improvements in physiological and patient‐reported outcomes. Our aims are to (a) evaluate the effects of virtual and in‐person exercise and coaching on long‐term adherence, (b) determine a benchmark of minutes of moderate intensity exercise associated with health status as related to key biobehavioural outcomes, (c) examine behaviour change theory‐defined constructs as mediators of exercise adherence and (d) evaluate intervention costs. Methods This 18 month, three‐group, repeated measures randomized controlled trial is enrolling 300 adults with HFpEF. Participants are randomized to enhanced usual care (EUC), virtual coaching, or in‐person coaching. Our intervention applies coaching strategies, informed by behaviour change theories, in one‐on‐one and group settings weekly for 12 months. Our objective is to compare the effects of each delivery method to the other and EUC on exercise adherence (defined as ≥ 120 min of moderate intensity exercise/week) at 12 months (primary endpoint) and 18 months (sustainability endpoint). Secondary outcomes include minutes of moderate intensity exercise needed to drive minimal clinically important differences in health status, biomarkers, patient‐reported symptoms and cost. Behaviour change theory‐defined constructs (e.g., self‐efficacy and outcome expectations) will be tested as mediators of exercise adherence. Results We expect that virtual coaching is equally as efficacious and more cost effective at promoting exercise adherence as in‐person coaching. Effects on exercise adherence may be mediated by theory‐defined constructs. We also expect to identify a threshold for minutes of moderate intensity exercise to potentially serve as an adherence benchmark in adults with HFpEF, one that may differ from the 120 min of exercise in our current definition. Conclusions These findings could shift the paradigm of exercise coaching in HF towards virtual delivery and increase the generalizability and reach of exercise training. This is especially important for adults with HFpEF as they are excluded from Medicare reimbursement for traditional cardiopulmonary rehabilitation.
Journals
2025 EN
Aradhyula Vaishnavi · Manandhar Sareeta · Sherafati Alborz
+10 more
Abstract Aims Heart failure with preserved ejection fraction (HFpEF) poses significant diagnostic, prognostic and therapeutic challenges, with high morbidity and mortality rates. Currently, there are limited predictors of outcomes in HFpEF patients. Circulating oxidized polyunsaturated fatty acyl lipids, or oxylipins, are known to initiate and resolve inflammation in cardiovascular diseases. However, their ability to predict mortality in HFpEF has not been established. We hypothesize that a panel of oxylipins can predict and stratify mortality risk in HFpEF patients. Methods and results Venous and arterial blood samples were collected during right heart catheterization from 90 HFpEF patients at a single institution. Patients were followed for 5 years to determine morbidity and mortality rates. We measured 143 arterial and 143 venous oxylipins in all study participants using liquid chromatography‐mass spectrometry. Volcano plots were used to visualize differences in oxylipins between survived and deceased groups. Receiver operator characteristic (ROC) curves were used to determine optimal biomarker cut‐points, and the relationship between the most significant oxylipins and mortality was assessed with Kaplan–Meier (KM) curves. HFpEF patients with 5‐year mortality had increased age, decreased body mass index, decreased diastolic blood pressure and worse renal function at baseline. They also had more severe pulmonary hypertension (PH) and right heart dysfunction. Volcano plot analysis revealed that arterial oxylipin 15‐keto prostaglandin F2a (PGF2a) was significantly associated with 5‐year mortality. ROC curve analysis identified an optimal cut‐point for 15‐keto PGF2a, and participants with elevated arterial 15‐keto PGF2a had significantly increased 5‐year mortality on KM curves. Multivariable adjusted analysis identified 15‐keto PGF2a as a significant predictor of 5‐year mortality (OR 1.82; CI 1.03, 3.5). Conclusions In this cohort of patients with HFpEF, arterial 15‐keto PGF2a, a stable metabolite of PGF2a, significantly predicted 5‐year mortality.