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This paper describes the development of a program of project-based learning in Calculus courses at a large urban research university. In this program, students developed research projects in consultation with a faculty advisor in their major, and supervised by their calculus instructors. Students wrote up their projects in a prescribed format based on scientific publishing norms. These write-ups were used as part of the basis for their course grades, typically as replacements for their final exams. Because this program involved a large number of students over several years, we were able to evaluate whether there were differences in how well students performed in subsequent courses (both mathematics and non-math courses required for engineering majors) (a) according to whether students were in sections offering projects, in concurrent non-project sections, or historical controls (prior to the project), and (b) among those in sections offering projects, according to whether they completed a project. We used as endpoints the pass and withdrawal rates in both the calculus courses themselves and in the follow-up courses. In Calculus II, students in project-option sections performed better than those in non-project-option sections, and this was true for every social subdivision examined (sex and race/ethnicity). There was a similar but smaller effect for Calculus III, which may thus be due to random fluctuations. Students submitting projects were more likely to go on to follow-up courses. Given enrollment in follow-up courses, there was no detectable performance difference between those who had and those who had not submitted projects; greater throughput does occur among those submitting projects, but this is associated with their greater enrollment in follow-up courses. In implementing this program, we encountered challenges in dealing with students, with the institution, and with individual faculty; we discuss the key challenges here.

This paper describes the development of a Peer-Led Guided Inquiry (PLGI) program for teaching calculus at the University of South Florida. This approach uses the POGIL (Process Oriented Guided Inquiry Learning) teaching strategy and the small group learning model PLTL (Peer-Led Team Learning). The developed materials used a learning cycle based on three phases of inquiry: exploration of a model, concept invention, and application. Fifty minutes weekly of lecture in Engineering and Life Sciences Calculus were replaced by the PLGI curriculum, where students worked in groups with peer leaders as instructors. The main outcomes measured were pass and withdrawal rates for sections using this approach compared to historical and concurrent sections not using PLGI. Our results showed higher pass rates in Life Sciences Calculus (18% gain in comparison to historical sections and 8.2% gain in comparison to concurrent non-PLGI sections). In Engineering Calculus, we also saw higher pass rates for PLGI sections (18.2% gain in comparison to historical rates and 4.0% gain in comparison to concurrent non-PLGI sections). Withdrawal rates also declined for both Life Sciences and Engineering Calculus. Both sexes had greater pass rates and lower withdrawal rates in both types of calculus. PLGI sections showed higher pass rates for African-American students in life sciences (16.5% gain in comparison to historical sections and 8.7% gain in comparison to concurrent non-PLGI sections). The impact of PLGI for African- American students was more dramatic in Engineering Calculus (24.9% gain in comparison to historical sections and a 17.6% gain in comparison to concurrent non-PLGI sections).

Historically, dense vegetation cover near buildings has caused power disruptions during weather phenomena. These types of severe storms impact the coast of Florida each year. However, challenges exist for obtaining both power outage data and calculating the impact of tree cover. NASA's Nighttime Lights, Black Marble, VNP46 product is utilized to analyze the natural and built environments. One aspect of the built environment that can be mapped with the Black Marble data is the megawatts of electricity used by the electrical power grid based on the magnitude of emitted nighttime light energy. This paper discusses using Black Marble data and other landscape variables within a probabilistic model to examine spatial patterns and map electricity outages with Bayesian networks. The research results indicate a high probability of a significant power outage when dense vegetation is present, but nuances in our natural and built environments like electric substations and land cover type alter the chance of reducing energy emissions. [ABSTRACT FROM AUTHOR]

Silvopastoral systems that integrate trees in pasture production systems are likely to enhance soil carbon (C) storage in lower soil layers due to the presence of deep tree roots. To quantify the relative soil C contribution from trees (C3 plants) and warm season grasses (C4 plants) in silvopastoral systems, soil samples were collected and analyzed from silvopastures of slash pine ( Pinus elliottii)+bahiagrass ( Paspalum notatum), and adjacent open pasture (OP), at six depths down to 125 cm, at four sites representing two major soil orders (Spodosols and Ultisols) of Florida. The plant sources of C in whole (nonfractionated) and three soil fraction sizes (250–2000, 53–250, and <53 μm) were traced using stable C isotope signatures. The silvopasture sites contained higher amounts of C3-derived soil organic carbon (SOC) compared with OP sites, at all soil depths. Slash pine trees (C3 plants) seemed to have contributed more C in the silt+clay-sized (<53 μm) fractions than bahiagrass (C4 plants), particularly deeper in the soil profile. Spodosols sites contained more C in the <53 μm fraction at and below the spodic horizon (occurring between 15 and 50 cm) in silvopasture compared with OP. The results indicate that most of SOC in deeper soil profiles and the relatively stable <53 μm C fraction were derived from tree components (C3 plants) in all the sites, suggesting that the tree-based pasture system has greater potential to store more stable C in the soil compared with the treeless system. [ABSTRACT FROM AUTHOR]

The article discusses research on the carbon storage of different fractionated size-classes of soils in a slash pine-based silvopasture (SP) and an adjacent open pasture (OP) system at four site in Florida, namely Alachua, Osceoloa, Hardee and Suwannee counties. Composite samples were collected from the sites, air dried and passed through a 2 millimeter (mm) sieve. The study found that the inclusion of trees in OPs and SPs increased soil organic carbon (SOC) in whole-soil, especially at lower depths.

The article presents information on the 1st World Congress of Agroforestry, held during June 27-July 2, 2004 in Orlando, Florida. The 750 presentations made during the congress included biological and ecological, communication and knowledge integration, economics, marketing and social issues. It indicates that agroforestry still is not of great interest to commercial producers of agricultural products. It was shown in the presentations that sustainability continued to be a major conceptual foundation of agroforestry. Inspite of this, there was considerable tropical-temperate contrast in efforts to attain sustainability. The congress was the first global forum for researchers, high-ranking government officials, practitioners, scientists and extension agents to develop strategies for research, education and training and development related to agroforestry. It can be very well stated from the current research trends and the level of discussions at the Congress, that agroforestry has developed into a robust discipline with worldwide applicability.

Understanding the belowground interactions between trees and crops is critical to successful management of agroforestry systems. In a study of competition for water in an alley cropping system consisting of pecan (Carya illinoensis) and cotton (Gossypium hirsutum) in a sandy loam soil (Rhodic Paleudult) in Jay, Florida, root systems of the two species were separated by trenching to 120 cm depth. A polyethylene barrier was installed in half of the plots. Spatial and temporal variations in soil water content, root distribution and water uptake by both species, and leaf area development and height of cotton were measured. Interspecific competition for water was greater in the non-barrier treatment near tree rows than at the alley center. Competition became evident 3 to 4 weeks after emergence of cotton and increased during the following 7 to 8 weeks. Compared with the non-barrier treatment, the barrier treatment had higher soil water content and better growth of cotton (height, leaf area, and fine root biomass). Cotton lint yield in the barrier treatment (677 kg ha-1) was similar to that in a sole-crop stand, but higher than in the non-barrier (502 kg ha-1) treatment. Lint production efficiency of plants was higher in the interior rows in the non-barrier treatment (0. 197 kg lint per square meter of leaf area, compared to 0. 117 kg in the barrier treatment). The results suggest that trenching or even deep disking parallel to the tree row may reduce competition for water, but the impact on tree growth cannot be established from this study. [ABSTRACT FROM AUTHOR]

Background/Purpose: Lupus nephritis (LN) is frequently associated with a poor long-term prognosis. Current non-invasive blood and urine tests do not reliably predict the course of LN. The objective of this study was to evaluate the performance of candidate urine biomarkers in predicting future kidney function in adults and children with LN. The biomarker candidates studies were liver-type fatty acid binding protein (L-FABP), albumin (Alb), monocyte chemoattractant protein 1 (MCP-1), Uromodulin, Transferrin and Hepcidin. Methods: L-FABP, Alb, MCP-1, Uromodulin, Transferrin and Hepcidin were measured by ELISA in urine from 70 adults and 42 children collected at the time of enrollment into prospective observational LN cohorts. Urine analytes were normalized to urine creatinine and logarithmically transformed. The association of each analyte to renal function loss (RFL), defined as a sustained increase of ≥25% in serum creatinine (SCr; adults) or a decrease in eGFR of ≥20% (children), was determined using a fixed effect model after adjusting for the age group (adult vs. child). In addition, the results were confirmed using Wilcoxon Rank Sum tests. Logistical models were used to predict the presence of RFL using each biomarker or a combination of the biomarkers. Biomarker performance in predicting RFL was assessed as the area under a ROC curve (AUC) corresponding to the logistical model. Results: 13 children and 22 adults had RFL during the mean follow-up period of 6.1 months and 60 months, respectively. Overall patients with RFL showed significantly higher levels ALB than those without RFL (p < 0.05, ). In addition, the levels of L-FABP, MCP-1, and Transferrin were also marginally higher in RFL (p-values < 0.1). The AUC using the combination of urine L-FABP, Alb, MCP-1 and Utransferrin was 0.66, slightly higher than those using any single biomarker as the predictor (ranging from 0.52-0.63). [ABSTRACT FROM AUTHOR]

Abstract: The status of residual phosphorus (P) and nitrogen (N) in agricultural soils is an environmental concern due to the possibility of the nutrients reaching adjacent water bodies through leaching or runoff. This concern is of particular importance in sandy and other coarse-textured, highly permeable soils. A 3-year study examined a pecan (Carya illinoensis K. Koch)–cotton (Gossypium hirsutum L.) alleycropping system situated on an Ultisol in northwest Florida, USA, to determine the effects of tree–root competition and fertilizer application (poultry litter versus inorganic) on soil nutrient status with time. Overall, competition for P between tree and crop roots appeared to be minimal in these soils. However, build-up of P occurred in soil over time. After 2 years of fertilizer application in the alleycropping system, the average concentration of Mehlich 1-P in the surface soil (0–5cm) increased from 74 to 106mgkg−1, and water soluble P increased from 5.9 to 7.2mgkg−1. In addition, accumulation of P in near-surface soils was slightly higher in manure-treated soils after the first year of treatment. A clay layer in the Ultisol at approximately 25cm largely prevented further downward movement of P. Overall, in terms of potential environmental risks from P accumulation and loss via runoff or leaching in these soils, the organic fertilizer appears to pose a greater long-term risk than the inorganic fertilizer if application is based on plant N requirement (a common practice) rather than P requirement. [Copyright &y& Elsevier]

Positive blood cultures have been identified in debilitated, stranded, and deceased green turtles ( Chelonia mydas ), suggestive of septicemia. Interpretation of these results is often difficult because multiple studies have previously identified bacteremia in clinically healthy reptiles. In this study, paired blood cultures and skin cultures obtained after aseptic preparation of the venipuncture site were collected from 50 immature free-ranging green turtles from Port Canaveral, Florida. Blood culture results were compared with health status (apparently healthy versus unhealthy, based on physical examination findings and appropriate body condition), date of collection, presence of external fibropapillomatosis, healed or unhealed injuries, and presence of barnacles. Weight, body condition score, body condition index, morphometric measures, volume of blood collected, and body temperature were compared between blood culture-positive and blood culture-negative turtles. Positive blood cultures were identified in 14% (7 of 50) of all turtles, including 15.6% (5 of 32) of apparently healthy turtles. Vibrio spp., Bacillus megaterium , Cellulomonas sp., and Staphylococcus pasteuri were isolated in blood culture from apparently healthy individuals. There was a significant association ( P = 0.048) between positive skin cultures and positive blood cultures, but isolates obtained were consistently different between paired results. There was no significant association ( P > 0.05) between blood culture results and health status, evidence of healed or unhealed injuries, external fibropapillomatosis, or presence of barnacles. Based on the results of this study, positive blood cultures suggestive of nonclinical bacteremia may be present in apparently healthy green turtles. The results of this study will aid the attending clinician in interpretation of blood culture results of apparently healthy or presumed septicemic captive and rehabilitating green turtles as part of the conservation and population recovery of this threatened species.