Shift in recreational fishing catches as a function of an extreme cold event

There is an increasing recognition that the influence of extreme climate events (ECE) can be more significant in structuring ecosystem dynamics than the gradual effects of climate change. Still, our understanding of the effects of climate extremes on ecosystem services such as marine fisheries lags behind those of effects of gradual change. The significance of ECEs depends on the severity of the disturbance event and the resilience of a fish community. South Florida experienced an extreme cold spell in 2010 that provided the opportunity to study recreational fisheries resilience to ECEs. Our main goal was to examine how recreational fishing catch structures responded to the cold spell, and illustrate any spatial-specific recovery trajectory dynamics after extreme ecological responses. To address this, we implemented multivariate and nonlinear statistics on fishing guide reports for 20 recreational species. A significant shift in the catch structure occurred after the event, suggesting a high sensitivity of fish populations and fisheries in the region to ECEs. All fishing regions considered were affected, but the trajectory of the response and recovery varied across study areas. While some fish species experienced an expected decline (due to mortality), other species manifested an increase in catch. Of the main seven species considered in nonlinear models, three experienced a decline (bonefish, snook, goliath grouper), two experienced an increase (red drum, gray snapper), and the two had various weak trends (tarpon, spotted seatrout). Three years after the event, the catch structure has not returned to the original state, indicating a possible state shift, whose stability needs to be determined in future tracking of affected populations. Future work should also address the extent to which harvest may interfere with resilience to ECEs. Our work highlights the need to account for rare environmental forcing induced by ECEs to ensure the ecological and economical sustainability of key services such as recreational fisheries

Resilience of a tropical sport fish population to a severe cold event varies across five estuaries in southern Florida

For species that are closely managed, understanding population resilience to environmental and anthropogenic disturbances (i.e., recovery trajectories across broad spatial areas) can guide which suite of management actions are available to mitigate any impacts. During January 2010, an extreme cold event in south Florida caused widespread mortality of common snook, Centropomus undecimalis, a popular sport fish. Interpretation of trends using fishery-independent monitoring data in five south Florida estuaries showed that changes in catch rates of adult snook (\u3e500 mm standard length) varied between no effects postevent to large effects and 4-yr recoveries. The reasons for the variation across estuaries are unknown, but are likely related to differences in estuary geomorphology and habitat availability (e.g., extent of deep rivers and canals) and differences in the proportions of behavior contingents (i.e., segments of the population that use divergent movement tactics) that place snook in different areas of the estuary during winter. Emerging awareness of the presence of behavior contingents, identification of overwintering sites, and improvements of abundance indices in remote nursery habitats should provide a better understanding of population resilience to disturbance events for snook. Given that changes in the frequency of short-lived, severe cold events are currently unknown, the findings and management actions described here for a tropical species living at the edge of its distribution should be useful to scientists forecasting the effects of climate change

A prospective phase II trial exploring the association between tumor microenvironment biomarkers and clinical activity of ipilimumab in advanced melanoma

<p>Abstract</p> <p>Background</p> <p>Ipilimumab, a fully human monoclonal antibody that blocks cytotoxic T-lymphocyte antigen-4, has demonstrated an improvement in overall survival in two phase III trials of patients with advanced melanoma. The primary objective of the current trial was to prospectively explore candidate biomarkers from the tumor microenvironment for associations with clinical response to ipilimumab.</p> <p>Methods</p> <p>In this randomized, double-blind, phase II biomarker study (ClinicalTrials.gov NCT00261365), 82 pretreated or treatment-naïve patients with unresectable stage III/IV melanoma were induced with 3 or 10 mg/kg ipilimumab every 3 weeks for 4 doses; at Week 24, patients could receive maintenance doses every 12 weeks. Efficacy was evaluated per modified World Health Organization response criteria and safety was assessed continuously. Candidate biomarkers were evaluated in tumor biopsies collected pretreatment and 24 to 72 hours after the second ipilimumab dose. Polymorphisms in immune-related genes were also evaluated.</p> <p>Results</p> <p>Objective response rate, response patterns, and safety were consistent with previous trials of ipilimumab in melanoma. No associations between genetic polymorphisms and clinical activity were observed. Immunohistochemistry and histology on tumor biopsies revealed significant associations between clinical activity and high baseline expression of FoxP3 (p = 0.014) and indoleamine 2,3-dioxygenase (p = 0.012), and between clinical activity and increase in tumor-infiltrating lymphocytes (TILs) between baseline and 3 weeks after start of treatment (p = 0.005). Microarray analysis of mRNA from tumor samples taken pretreatment and post-treatment demonstrated significant increases in expression of several immune-related genes, and decreases in expression of genes implicated in cancer and melanoma.</p> <p>Conclusions</p> <p>Baseline expression of immune-related tumor biomarkers and a post-treatment increase in TILs may be positively associated with ipilimumab clinical activity. The observed pharmacodynamic changes in gene expression warrant further analysis to determine whether treatment-emergent changes in gene expression may be associated with clinical efficacy. Further studies are required to determine the predictive value of these and other potential biomarkers associated with clinical response to ipilimumab.</p

Chronic kidney disease after liver, cardiac, lung, heart–lung, and hematopoietic stem cell transplant

Patient survival after cardiac, liver, and hematopoietic stem cell transplant (HSCT) is improving; however, this survival is limited by substantial pretransplant and treatment-related toxicities. A major cause of morbidity and mortality after transplant is chronic kidney disease (CKD). Although the majority of CKD after transplant is attributed to the use of calcineurin inhibitors, various other conditions such as thrombotic microangiopathy, nephrotic syndrome, and focal segmental glomerulosclerosis have been described. Though the immunosuppression used for each of the transplant types, cardiac, liver and HSCT is similar, the risk factors for developing CKD and the CKD severity described in patients after transplant vary. As the indications for transplant and the long-term survival improves for these children, so will the burden of CKD. Nephrologists should be involved early in the pretransplant workup of these patients. Transplant physicians and nephrologists will need to work together to identify those patients at risk of developing CKD early to prevent its development and progression to end-stage renal disease

Analysis of arterial intimal hyperplasia: review and hypothesis

which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background: Despite a prodigious investment of funds, we cannot treat or prevent arteriosclerosis and restenosis, particularly its major pathology, arterial intimal hyperplasia. A cornerstone question lies behind all approaches to the disease: what causes the pathology? Hypothesis: I argue that the question itself is misplaced because it implies that intimal hyperplasia is a novel pathological phenomenon caused by new mechanisms. A simple inquiry into arterial morphology shows the opposite is true. The normal multi-layer cellular organization of the tunica intima is identical to that of diseased hyperplasia; it is the standard arterial system design in all placentals at least as large as rabbits, including humans. Formed initially as one-layer endothelium lining, this phenotype can either be maintained or differentiate into a normal multi-layer cellular lining, so striking in its resemblance to diseased hyperplasia that we have to name it &quot;benign intimal hyperplasia&quot;. However, normal or &quot;benign &quot; intimal hyperplasia, although microscopically identical to pathology, is a controllable phenotype that rarely compromises blood supply. It is remarkable that each human heart has coronary arteries in which a single-layer endothelium differentiates earl

Turning Passive Detection Systems into Field Experiments: An Application Using Wetland Fishes and Enclosures to Track Fine-Scale Movement and Habitat Choice

Understanding habitat selection and movement remains a key question in behavioral ecology. Yet, obtaining a sufficiently high spatiotemporal resolution of the movement paths of organisms remains a major challenge, despite recent technological advances. Observing fine-scale movement and habitat choice decisions in the field can prove to be difficult and expensive, particularly in expansive habitats such as wetlands. We describe the application of passive integrated transponder (PIT) systems to field enclosures for tracking detailed fish behaviors in an experimental setting. PIT systems have been applied to habitats with clear passageways, at fixed locations or in controlled laboratory and mesocosm settings, but their use in unconfined habitats and field-based experimental setups remains limited. In an Everglades enclosure, we continuously tracked the movement and habitat use of PIT-tagged centrarchids across three habitats of varying depth and complexity using multiple flatbed antennas for 14 days. Fish used all three habitats, with marked species-specific diel movement patterns across habitats, and short-lived movements that would be likely missed by other tracking techniques. Findings suggest that the application of PIT systems to field enclosures can be an insightful approach for gaining continuous, undisturbed and detailed movement data in unconfined habitats, and for experimentally manipulating both internal and external drivers of these behaviors

Illustrating the value of cross-site comparisons: Habitat use by a large, euryhaline fish differs along a latitudinal gradient

Plasticity in life-history traits and behaviors allows organisms to track spatial environmental variation, such as that resulting from a latitudinal gradient. In estuaries, hydrological patterns can vary greatly with latitude, causing variable habitat use patterns across a species’ range. For Common Snook (Centropomus undecimalis) a large euryhaline fish, seasonal movements between the open estuary and freshwater reaches of rivers have been documented. We hypothesized that the timing of river use by Snook would be driven primarily by the magnitude of freshwater inflow, except at the northern limit of its range where lethal water temperatures may be a stronger influence. Data from electrofishing studies (2012–2016) conducted in rivers associated with four estuaries along a latitudinal gradient in western Florida were compared for seasonal differences in Snook abundance using negative binomial regression. In rivers of southwestern Florida (those in Everglades and Charlotte Harbor), Snook abundances increased three-fold during the time of year when surface waters inundating floodplains recede and force prey into the main stems of rivers. These hydrologically driven processes, and surges in Snook abundance, occurred during spring in the Everglades and fall in rivers of Charlotte Harbor. In Tampa Bay rivers, which have less freshwater inflow than the rivers farther south, Snook abundance differed little between seasons. In spring-fed rivers north of Tampa Bay, Snook abundances in fall and winter were twice those of spring and summer; stable water temperatures were thought to provide thermal refuge at the northernmost range of Snook. This work illustrates how the timing of habitat use by a species, and the underlying reasons, can differ greatly among sites. It also demonstrates the value of cross-site comparisons in providing for a more complete understanding of how a species uses available habitats across its range

Ecological niche partitioning within a large predator guild in a nutrient-limited estuary

Within oligotrophic ecosystems, resource limitations coupled with interspecific variation in morphology, physiology, and life history traits may lead to niche partitioning among species. How generalist predators partition resources and their mechanisms, however, remain unclear across many ecosystems. We quantified niche partitioning among upper trophic level coastal and estuarine species: American alligators (Alligator mississippiensis), bull sharks (Carcharhinus leucas), common bottlenose dolphins (Tursiops truncatus), common snook (Centropomus undecimalis), and Atlantic tarpon (Megalops atlanticus) in the Shark River Estuary of the Florida Coastal Everglades, USA using acoustic telemetry, stable isotope analysis, and visual surveys, combined with published diet and life history demographic information. Spatial and isotopic niche overlap occurred among most species, with variability in partitioning among interspecific interactions. However, seasonal variability in habitat use, movements patterns, and trophic interactions may promote coexistence within this resource-limited estuary. Beyond guild-level niche partitioning, predators within the Shark River Estuary also exhibit partitioning within species through individual specializations and divergent phenotypes, which may lead to intraspecific variability in niche overlap with other predators. Niche differentiation expressed across multiple organizational levels (i.e., populations and communities) coupled with behavioral plasticity among predators in oligotrophic ecosystems may promote high species diversity despite resource limitations, which may be important when species respond to natural and human-driven environmental change

Keeping up with the Silver King: Using cooperative acoustic telemetry networks to quantify the movements of Atlantic tarpon (Megalops atlanticus) in the coastal waters of the southeastern United States

Understanding the nature of migratory behaviors within animal populations is critical to develop and refine conservation and management plans. However, tracking migratory marine animals across life stages and over multiple years is inherently difficult to achieve, especially for highly migratory species. In this paper, we explore the use of acoustic telemetry to characterize the spatial ecology of Atlantic tarpon (Megalops atlanticus), elucidate the ecology of this poorly studied species, and ultimately inform conservation and management. Using the data from twenty-two acoustically tagged Atlantic tarpon, we found a diversity of tarpon migratory patterns, including spatial and temporal overlap for some individuals. We also reveal fine scale movements within specific ecosystems, as well as a range of distributions and connectivity across coastal waters of the southeastern United States of America. For tarpon with tracking durations greater than one month (n = 13), we found heterogeneous space use and migratory connectivity with some tarpon remaining close to their capture location while others migrated hundreds of kilometers. In addition, we were able to identify a northern and southern limit for one migratory tarpon that had detections spanning over 365 days. We share analyses on Atlantic tarpon data, including model-driven approaches and network analysis, to investigate movement strategies and space use, which may be pertinent to other studies involving highly migratory species. The project was a collaborative effort involving several acoustic telemetry networks which enabled the monitoring of broad- and fine-scale movements for extended periods of time that would normally be difficult to achieve with other monitoring techniques. Although challenges exist with applying acoustic telemetry to monitor highly migratory species, we also discuss its value in enabling researchers to assess movements and space use beyond the focal species, such as cross-ecosystem comparisons and multi-species interactions