A Functional Trait Approach to Examine Plant Community Dynamics in South Florida Hardwood Hammock Forests

The tropical hardwood forests of south Florida persist as well-drained patches of broadleaf forest separated by brackish water swamp, marsh, or pineland. In this dissertation, a functional trait approach was used to understand the structure and dynamics of these communities and their responses to abiotic and biotic variation. Twenty-seven permanent plots (20 x 20 m2) were established across the south Florida landscape, representing four sub-regions: Everglades marsh, Long Pine Key, Upper Keys, and Lower Keys. Community weighted mean trait values for four of six selected traits showed significant inter-sub-regional variation. Out of them, three traits (specific leaf area, tree height, and leaf phosphorus) increased significantly from dry and low productivity Florida Keys in the south to the moist and productive areas on the south Florida mainland, while wood density showed the opposite pattern. Trait variance ratios (T-statistic metrics) was used to explore internal filtering (processes that operate within a community) and external filtering (processes that operate at larger scale than that of the individual population or community) on community structure. Both external and internal filtering in the functional composition of south Florida hardwood hammock forest were important for local communities differing in freshwater accessibility, or that occupy different positions along strong edaphic or climatic gradients. To understand the underlying mechanisms that drive species assembly during forest succession in Florida dry sub-tropical forest, 13 leaf, stem, reproductive, and architectural traits of resident tree species across the successional gradient were measured. Tests of null models showed that younger communities are shaped by environmentally driven processes, while mature communities are shaped by competitively driven processes. The overall trait similarities among species present in North Key Largo tropical dry forest suggest that tree species are specialists on the local environment, and their ability to survive and grow in a stressful environment may be more important than competition for resources at larger scale. Moreover, tree species in these forests may exhibit specialization or trait plasticity in coping with drought by changes in their stomatal morphology or activity, allowing for a balance between gas exchange and water loss in a periodically stressful environment. A significant negative correlation between stomatal density and size, and a positive correlation between leaf δ13C and stomatal density were observed across habitat gradient for one of the dominant hardwood hammock species (Bursera simaruba). Small and densely distributed stomates in tandem seems to represent a strategy that allows hammock species to conserve water under physiological drought. Furthermore, findings from this work also showed both intra- and inter-specific trait variation at regional and local scales influence community assembly patterns in hardwood hammock communities in South Florida

Determination of Nutrient Limitation on Trees Growing in Loxahatchee Impoundment Landscape Assessment (LILA) Tree Islands, Florida

The purpose of this study was to determine the general patterns of response by tree species common to Everglades Tree Islands (TI) when conditions limiting optimal growth are improved by fertilization on LILA tree islands. Experiments were conducted on constructed TI in the Loxahatchee Impoundment Landscape Assessment (LILA). Thirty-six trees of two species, Annona glabra and Chrysobalanus icaco, were randomly selected on each of four tree islands. Two tree islands have peat overlying limestone cores and two are composed solely of peat. Each tree was treated with one of three nutrient regimes: +N, +P, or Control (no addition of nutrients). A highly significant P-treatment effect on growth rate, leaf TP and leaf N:P ratio were observed in both species in comparison to Control trees. In contrast, neither of the species responded to N-fertilization. The mass N:P ratios and δ13C in P-treated trees exhibited a positive correlation with Relative Elevation (RE) for both species. These findings suggested that the tree growth at LILA tree islands was P-limited on both substrates (limestone and peat)

Uterine Endoplasmic Reticulum Stress and Its Unfolded Protein Response May Regulate Caspase 3 Activation in the Pregnant Mouse Uterus

We have previously proposed that uterine caspase-3 may modulate uterine contractility in a gestationally regulated fashion. The objective of this study was to determine the mechanism by which uterine caspase-3 is activated and consequently controlled in the pregnant uterus across gestation. Utilizing the mouse uterus as our gestational model we examined the intrinsic and extrinsic apoptotic signaling pathways and the endoplasmic reticulum stress response as potential activators of uterine caspase-3 at the transcriptional and translational level. Our study revealed robust activation of the uterine myocyte endoplasmic reticulum stress response and its adaptive unfolded protein response during pregnancy coinciding respectively with increased uterine caspase-3 activity and its withdrawal to term. In contrast the intrinsic and extrinsic apoptotic signaling pathways remained inactive across gestation. We speculate that physiological stimuli experienced by the pregnant uterus likely potentiates the uterine myocyte endoplasmic reticulum stress response resulting in elevated caspase-3 activation, which is isolated to the pregnant mouse myometrium. However as term approaches, activation of an elevated adaptive unfolded protein response acts to limit the endoplasmic reticulum stress response inhibiting caspase-3 resulting in its decline towards term. We speculate that these events have the capacity to regulate gestational length in a caspase-3 dependent manne

Monitoring of Tree Island Condition in the Southern Everglades: Annual Report 2011

Tree islands, a prominent feature in both the marl prairie and ridge and slough landscapes of the Everglades, are sensitive to large-scale restoration actions associated with the Comprehensive Everglades Restoration Plan (CERP) authorized by the Water Resources Development Act (WRDA) 2000 to restore the south Florida ecosystem. More specifically, changes in hydrologic regimes at both local and landscape scales are likely to affect the internal water economy of islands, which in turn will influence plant community structure and function. To strengthen our ability to assess the “performance” of tree island ecosystems and predict how these hydrologic alterations would translate into ecosystem response, an improved understating of reference conditions of vegetation structure and function, and their responses to major stressors is important. In this regard, a study of vegetation structure and composition in relation to associated physical and biological processes was initiated in 2005 with initial funding from Everglades National Park and South Florida Water Management District (SFWMD). The study continued through 2011 with funding from US Army Corps of Engineers (USACOE) (Cooperative Agreement # W912HZ-09-2-0019 Modification No.: P00001)

Trait‐based community assembly pattern along a forest succession gradient in a seasonally dry tropical forest

We aimed to determine the important functional dimensions that may drive forest succession and community assembly patterns in dry tropical forests. We investigated whether there were patterns in specific functional strategies during succession in the dry tropical forests of the Florida Keys, whose unique physical setting includes nutrient‐stressed, salt‐stressed, and water‐limited environments. The study, which focused on ten traits, determined the leading trait dimensions by which species differentiate from one another in the study area. The general patterns of trait covariation at individual sites and among species were analyzed using principal component analysis. Trait niche overlap indices were calculated for all species sampled across all plots. Evidence for/against likely community assembly processes was tested using the coefficient of heterogeneity to determine whether variation within and among five key traits was clustered, random, or evenly distributed across young, old, or all measured forest stands. A combination of plant architecture, wood density, and three leaf traits (specific leaf area, leaf phosphorus, and leaf nitrogen) comprised a key set of functional traits that are important for understanding the community assembly process in dry tropical forest. Older forest stands were dominated by species with low specific area, low leaf nitrogen content, dense wood, and deeper and narrower canopies. Trees of old forests had leaves with lighter carbon isotope composition, suggesting that such individuals were making more efficient use of scarce water. Tests of trait distributions showed significant clustering across forests of all ages. When individual trait distributions in old stands were tested, they displayed either randomly or evenly distributed traits across trait niche space, indicating that resource partitioning was predominant in shaping community composition. Physical traits of trees in young communities are associated with resource acquisitive strategies, while old communities are dominated by species with traits that enhance survival in environments defined by competition or chronic resource scarcity

Impact of cyclosporine A use in the prevention of reperfusion injury in acute myocardial infarction: A meta-analysis

Background: Reperfusion injury is an important limiting factor associated with revascularization in acute myocardial infarction (AMI). Various therapies have been tried in an attempt to prevent reperfusion injury, but the search has been elusive. The role of cyclosporine A (CsA) in the prevention of reperfusion injury in AMI is still not clear. The objective of this study was to find out whether CsA is beneficial in reducing reperfusion injury in acute ST elevation myocardial infarction. Methods: We performed a systematic search of Pubmed, Scopus, clinicaltrial.gov, and Cochrane Database for randomized control trials (RCT) measuring the effect of CsA in AMI compared to a placebo. The Mantel-Haenszel method and random effect model were used to analyze the data. A total of 1,566 patients (776 in the CsA group and 790 in the placebo group), who participated in 5 RCTs were included in our meta-analysis. Results: We did not find any significant differences between the CsA and placebo groups in terms of all-cause death (odds ratio [OR] 1.21, 95% confidence interval [CI] 0.78–1.87) and cardiovascular death (OR 1.05, 95% CI 0.66–2.49). Similarly, we did not find any significant differences in terms of cardiogenic shock, recurrent ischemia and myocardial infarction, heart failure and echocardiographic outcomes. Conclusions: Cyclosporine A is not helpful in preventing reperfusion injury in AMI.

The sustainability of trade in wild plants—A data-integration approach tested on critically endangered Nardostachys jatamansi

While the demand for many products from wild-harvested plants is growing rapidly, the sustainability of the associated plant trade remains poorly understood and understudied. We integrate ecological and trade data to advance sustainability assessments, using the critically endangered Nardostachys jatamansi in Nepal to exemplify the approach and illustrate the conservation policy gains. Through spatial distribution modeling and structured interviews with traders, wholesalers, and processors, we upscale district-level trade data to provincial and national levels and compare traded amounts to three sustainable harvest scenarios derived from stock and yield data in published inventories and population ecology studies. We find increased trade levels and unsustainable harvesting focused in specific subnational geographical locations. Data reported in government records and to CITES did not reflect estimated trade levels and could not be used to assess sustainability. Our results suggest that changing harvesting practices to promote regeneration would allow country-wide higher levels of sustainable harvests, simultaneously promoting species conservation and continued trade of substantial economic importance to harvesters and downstream actors in the production network. The approach can be applied to other plant species, with indication that quick and low-cost proxies to species distribution modeling may provide acceptable sustainability estimates at aggregated spatial levels

The global burden of adolescent and young adult cancer in 2019 : a systematic analysis for the Global Burden of Disease Study 2019

Background In estimating the global burden of cancer, adolescents and young adults with cancer are often overlooked, despite being a distinct subgroup with unique epidemiology, clinical care needs, and societal impact. Comprehensive estimates of the global cancer burden in adolescents and young adults (aged 15-39 years) are lacking. To address this gap, we analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, with a focus on the outcome of disability-adjusted life-years (DALYs), to inform global cancer control measures in adolescents and young adults. Methods Using the GBD 2019 methodology, international mortality data were collected from vital registration systems, verbal autopsies, and population-based cancer registry inputs modelled with mortality-to-incidence ratios (MIRs). Incidence was computed with mortality estimates and corresponding MIRs. Prevalence estimates were calculated using modelled survival and multiplied by disability weights to obtain years lived with disability (YLDs). Years of life lost (YLLs) were calculated as age-specific cancer deaths multiplied by the standard life expectancy at the age of death. The main outcome was DALYs (the sum of YLLs and YLDs). Estimates were presented globally and by Socio-demographic Index (SDI) quintiles (countries ranked and divided into five equal SDI groups), and all estimates were presented with corresponding 95% uncertainty intervals (UIs). For this analysis, we used the age range of 15-39 years to define adolescents and young adults. Findings There were 1.19 million (95% UI 1.11-1.28) incident cancer cases and 396 000 (370 000-425 000) deaths due to cancer among people aged 15-39 years worldwide in 2019. The highest age-standardised incidence rates occurred in high SDI (59.6 [54.5-65.7] per 100 000 person-years) and high-middle SDI countries (53.2 [48.8-57.9] per 100 000 person-years), while the highest age-standardised mortality rates were in low-middle SDI (14.2 [12.9-15.6] per 100 000 person-years) and middle SDI (13.6 [12.6-14.8] per 100 000 person-years) countries. In 2019, adolescent and young adult cancers contributed 23.5 million (21.9-25.2) DALYs to the global burden of disease, of which 2.7% (1.9-3.6) came from YLDs and 97.3% (96.4-98.1) from YLLs. Cancer was the fourth leading cause of death and tenth leading cause of DALYs in adolescents and young adults globally. Interpretation Adolescent and young adult cancers contributed substantially to the overall adolescent and young adult disease burden globally in 2019. These results provide new insights into the distribution and magnitude of the adolescent and young adult cancer burden around the world. With notable differences observed across SDI settings, these estimates can inform global and country-level cancer control efforts. Copyright (C) 2021 The Author(s). Published by Elsevier Ltd.Peer reviewe

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Primary Idiopathic Osteoarthropathy: Could It Be Related to Alcoholism?

Background. Hypertrophic osteoarthropathy (HOA) is a syndrome characterized by abnormal proliferation of the skin and bony structures at the distal extremities resulting in digital clubbing, periosteal bony reaction, and joint effusion. It can be primary (idiopathic) without any clear identifiable etiology as well as secondary to variety of systemic diseases most notably lung pathology. Case Presentation. We describe a rare case of primary idiopathic osteoarthropathy in a male patient who presented with severe pain and tenderness in his legs. His history was significant for long standing alcoholism. Physical examination showed severe fingers and toes clubbing. He reported similar changes in his mother. Clinical and radiological findings were remarkable for distal leg tenderness and diffuse periosteal bony reactions, respectively. Computerized tomography scan failed to show any pathology apart from fatty liver infiltration. In the absence of obesity or diabetes, this was consistent with alcoholic steatosis. He was started on nonsteroidal anti-inflammatory drug which dramatically improved his symptoms. Conclusion. Primary hypertrophic osteoarthropathy should be considered in a previously healthy person presenting with bony pain and finger clubbing especially after ruling out the common secondary causes. Moreover, alteration of prostaglandin metabolism secondary to alcoholic consumption might be a contributing factor