Embryonic Hypoxia Alters Exploratory Movement in Adult Geckos

Environmental changes, such as temporary hypoxia, during the embryonic stage can impair brain development in leopard geckos (Eublepharis macularius). We therefore tested whether this early brain damage produces behavioral deficits that persist into adulthood. The organization and kinematic properties of non-visual exploration between normal (n = 14) and hypoxia (n = 3) geckos were compared. Geckos were individually placed on a circular table (diam=91cm) and allowed to explore darkness for 60min while being recorded. The gecko\u27s coordinates were calculated at 5frames/second. Movement properties within each trial were evaluated across five 10min epochs. Total distance, peak speed, movement scaling (correlation between path length and peak speed), distance ratio, heading error, total stop time, mean stop time, number of stops, number of progressions, and progression distance were compared between groups and across epochs with a mixed Group X Epoch ANOVA. Movement properties did not differ across time epochs. However, hypoxia animals showed significantly lower peak speed [F(1,15) = 6.18, p = .025], and greater movement scaling [F(1,15) = 5.78, p = .03] scores, compared to controls. These results indicate that brain damage caused by early hypoxia causes adult geckos to move slowly, but they retain the ability to move normally and accurately estimate distance. Thus, the reduced speed is not caused by a general movement deficit. These preliminary results suggest that embryonic hypoxia alters exploratory behavior that persists into adulthood. This on-going study will continue to evaluate exploratory movement, and data will be added to the presentation as they become available

Neuronal Density in Navigation-Related Regions of the Adult Leopard Gecko Brain

Hypoxic conditions disrupt brain development in many species, but oxygen deprivation may be particularly detrimental to ectotherms such as reptiles. Our preliminary data suggest the brains of embryonic leopard geckos (Eublepharis macularius) are damaged following brief hypoxic conditions in ovo, and these developmental changes are associated with altered exploratory behavior in adulthood. The objective of this study is to understand the effects of such hypoxic conditions neuronally once the geckos have reached adulthood. However, no previous studies have evaluated the neuronal density of navigation-related brain regions in normal adult geckos, or whether these regions are sensitive to early hypoxia. Here, we present the optical density measurements from the medial cortex, the dorsal and lateral cortex, the dorsal lateral thalamus, and the septal region of adult geckos (n=2) that developed in normoxic conditions, to establish a baseline measure of cell density. Mean (SEM) optical density values are shown in the Table. These optical density values provide an important baseline for our on-going evaluation of neuronal sensitivity to hypoxic conditions in ovo. We anticipate that neuronal density values from hypoxic geckos will be reduced, relative to those of geckos that develop in normoxic conditions

Genome Sequence and Annotation of the B3 Mycobacteriophage Phayeta

Mycobacteriophage Phayeta was extracted from soil near Myrtle Beach, South Carolina using Mycobacterium smegmatis as a host. Annotation of the 68,700 base-pair circularly permuted genome identified 104 predicted protein-encoding genes, 34 of which have functional assignments. This article was published Open Access through the CCU Libraries Open Access Publishing Fund. The article was first published in Microbiology Resource Announcements: https://doi.org/10.1128/MRA.00915-2

A 92-foot Douglas-fir in a weighing lysimeter

A soil container 12 feet in diameter and 4 feet deep was constructed around the root ball of a 92-foot Douglas-fir tree in a naturally regenerated stand. The weighing mechanism, consisting of 550 feet of 2.5-inch butyl rubber tubing filled with water connected to a standpipe, was placed under the soil container. A 1/32-inch change in water within the standpipe is equivalent to a weight change of 15.5 pounds or 1.89 gallons of water. The container, soil, and tree weighed 63,638 pounds

A process-based model of conifer forest structure and function with special emphasis on leaf lifespan

We describe the University of Sheffield Conifer Model (USCM), a process-based approach for simulating conifer forest carbon, nitrogen, and water fluxes by up-scaling widely applicable relationships between leaf lifespan and function. The USCM is designed to predict and analyze the biogeochemistry and biophysics of conifer forests that dominated the ice-free high-latitude regions under the high pCO2 “greenhouse” world 290–50 Myr ago. It will be of use in future research investigating controls on the contrasting distribution of ancient evergreen and deciduous forests between hemispheres, and their differential feedbacks on polar climate through the exchange of energy and materials with the atmosphere. Emphasis is placed on leaf lifespan because this trait can be determined from the anatomical characteristics of fossil conifer woods and influences a range of ecosystem processes. Extensive testing of simulated net primary production and partitioning, leaf area index, evapotranspiration, nitrogen uptake, and land surface energy partitioning showed close agreement with observations from sites across a wide climatic gradient. This indicates the generic utility of our model, and adequate representation of the key processes involved in forest function using only information on leaf lifespan, climate, and soils

Individual tree and stand-level carbon and nutrient contents across one rotation of loblolly pine plantations on a reclaimed surface mine

While reclaimed loblolly pine (Pinus taeda L.) plantations in east Texas, USA have demonstrated similar aboveground productivity levels relative to unmined forests, there is interest in assessing carbon (C) and nutrients in aboveground components of reclaimed trees. Numerous studies have previously documented aboveground biomass, C, and nutrient contents in loblolly pine plantations; however, similar data have not been collected on mined lands. We investigated C, N, P, K, Ca, and Mg aboveground contents for first-rotation loblolly pine growing on reclaimed mined lands in the Gulf Coastal Plain over a 32-year chronosequence and correlated elemental rates to stand age, stem growth, and similar data for unmined lands. At the individual tree level, we evaluated elemental contents in aboveground biomass components using tree size, age, and site index as predictor variables. At the stand-level, we then scaled individual tree C and nutrients and fit a model to determine the sensitivity of aboveground elemental contents to stand age and site index. Our data suggest that aboveground C and nutrients in loblolly pine on mined lands exceed or follow similar trends to data for unmined pine plantations derived from the literature. Diameter and height were the best predictors of individual tree stem C and nutrient contents (R ≥ 0.9473 and 0.9280, respectively) followed by stand age (R ≥ 0.8660). Foliage produced weaker relationships across all predictor variables compared to stem, though still significant (P ≤ 0.05). The model for estimating stand-level C and nutrients using stand age provided a good fit, indicating that contents aggrade over time predictably. Results of this study show successful modelling of reclaimed loblolly pine aboveground C and nutrients, and suggest elemental cycling is comparable to unmined lands, thus providing applicability of our model to related systems

An improved model for estimating emissions of volatile organic compounds from forests in the eastern United States

The US Department of Agriculture, Forest Service Forest Inventory and Analysis Eastwide Database is used to describe the areal extent, species composition, and tree diameter distributions of United States forests. Horizontal canopy occupancy by genera is then estimated as a function of diameter at breast height. Growing season peak foliar masses are derived from the empirical literature for canopies of deciduous and coniferous genera. A simple canopy model is used to adjust photosynthetically active solar radiation at five vertical levels in the canopy. Leaf temperature and photosynthetically active radiation derived from ambient conditions above the forest canopy are then used to drive empirical equations to estimate genus level emission rates of BVOCs vertically through forest canopies. -Author

Effect of endophytes on Anethum graveolens (dill), synthesis of volatile organic compounds

Volatile organic compounds (VOC’s) are emitted from plants and interact with the plants environment in various ways. Terpenes are the most widely released plant VOC’s, and specifically monoterpenes play a key role in the interactions between plants and insects. In Anethum graveolens (dill), methyl eugenol and limonene, are volatile compounds that attract various pollinators to the plant. Endophytes have been discovered to live symbiotically with various plants, but little is known regarding their role in the synthesis of volatile organic compounds. We propose that the presence of endophytes in Anethum graveolens (dill) will increase the synthesis of these secondary metabolites. Dill plants will be grown under four growth conditions: 1) sterile seeds and sterile soil, 2) unsterile seeds and sterile soil, 3) unsterile seeds and sterile soil, 4) unsterile seeds and unsterile soil. After maturation of the plants, floral organs will be sampled to examine gene expression of enzymes involved in the synthesis of methyl eugenol and limonene. The molecular data will be analyzed to determine the effect of the endophytes on the synthesis of these volatile organic compounds. Understanding the effect of endophytes on the synthesis of VOC\u27s could potentially be used to address multiple agricultural and ecological issues regarding pollination