Current concerns about inorganic contaminants in food products have raised consumer awareness of anthropogenic sources of heavy metal contamination in ecosystems and their potential threat to human health. Mining and exploration of mineralized zones is a major source of such contamination. Mining throughout the Patagonia Mountains, Arizona, has left a legacy of surface water contamination by acid mine drainage (AMD). This study assessed the impacts of AMD on soils and plants throughout the study area. Concentrations, transport, and loading of heavy metals (Ag, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, and Zn) in soils and plants was quantified using total concentrations, suggested toxic levels, and plant and soil pollution indices. Pollution indices were modified to include antimony and molybdenum. Pollution indices greater than 100 were found in areas disturbed by mining, remediation sites and beyond. Cattle grazing on grasses contaminated by metals were documented.

A colony of social insects has many tasks to complete for the good of the colony. The tasks, such as brood care, feeding, foraging and building, could be split among its members (implying specialization). Alternatively, ants could just freely switch between tasks, either doing whatever needs to be done or whatever tasks they come into contact with. If individuals switch from one task to another, they may incur costs, including a time cost. So far, research has yet to quantify such task switching costs. To learn more about switching cost, specifically quantifying the cost in terms of time, videos of Temnothorax rugatulus were observed for specific tasks, such as brood care, feeding, foraging and building. The switching costs were measured in two ways depending on whether the non-switching time or switching time were being measured. For the non-switching time between bouts of the same task, the interval time started when the ant stopped touching the brood item and ended when the ant started touching the brood item. For the switching time between two different tasks, time began when the ant stopped one task and ended when the ant began a second task. The interval time was calculated by recording the time, using the timeline on the video, that the ant stopped one task (or bout of one task) and moved on the next. The data collected from the videos were analyzed using a Welch Two-Sample T-test. Through the study, it was discovered that there was, in fact, no significant delay when Temnothorax rugatulus switch from one task to another.

Roughgarden et al. (2006) proposed a theory called social selection as a behavioral game theoretic model for sexual reproduction that incorporates both competition and cooperation in 2006. Players oscillate between playing competitively to maximize their individual fitness, leading to a Nash Competitive Equilibrium, and playing cooperatively to maximize a team fitness function, leading to a Nash Bargaining Solution. Roughgarden et al. (2006) gives rates of change for both the competitive state and the cooperative state, but does not explain her rates or how to switch between the states in sufficient detail. We test and rederive the rates, critiquing an assumption that the derivation of such a rate must make, as well as create a probabilistic model that switches between the two states. We test our model on the reproductive behaviors of Symphodus tinca, the peacock wrasse. The results follow the trajectory of the reproductive strategies for the wrasse throughout the breeding system, suggesting that cooperation could be a mechanism through which wrasse change their reproductive behaviors. However, the inputs to the model need to be analyzed more critically. Future work could include deriving rates for competitive play and cooperative play that do not rely on assumptions of being able to quantify strategy allocation proportion and refining the model and drawing generalized conclusions about it.

Locust swarms cause famine and hunger in parts of Sub-Saharan Africa as they travel across croplands and eat vegetation. Current models start with biological properties of locusts and analyze the macroscopic behavior of the system. These models exhibit the desired migratory behavior, but do so with too many parameters. To account for this, a new model, the Alignment and Intermittent Motion (AIM) model, is derived with minimal assumptions. AIM is constructed with regards to locust biology, allowing it to elicit biologically correct locust behavior: the most noteworthy being the fingering of hopper bands. A Particle-in-Cell method is used to optimize simulations, allowing for trials of up to 106 particles over reasonable timescales. We analyze the shapes of these swarms, note the similarities between simulations of large and small swarms, and propose possible methods for analyzing simulation metrics.

Ubiquitylation is an important post-translational modification and can be reversed by the action of deubiquitinating (DUB) enzymes. The ubiquitylation and deubiquitylation of target proteins are significant in terms of regulating cellular events such as protein degradation, signal transduction, vesicle trafficking, DNA repair and apoptosis. Chromosomal band 17q23 is frequently amplified in breast cancers and harbors a predicted ubiquitin specific protease gene, USP32 (ubiquitin specific protease 32). Given its potential role in breast cancer, we aimed to characterize USP32 for its potential DUB activity. Bioinformatic analysis of USP32 and known yeast and mouse DUBs suggested presence of Cys-His domains which are common in active DUBs of the USP superfamily. Our in vivo and in vitro DUB activity assays revealed that USP32 was indeed an active deubiquitinating enzyme. To investigate its substrate specificity and kinetic properties, USP32 was expressed in insect cell culture to be isolated and purified. Using isolated USP32 protein, diubiquitin assay was performed with all seven types of diubiquitin (K6, K11, K27, K29, K33, K48 and K63) as well as linear diubiquitin. Results showed that USP32 was able to cleave all seven types of ubiquitin linkages with higher cleavage efficiency for K6, K11, K48 and K63-linked diubiquitin. Moreover, kinetic parameters, Km, kcat and kcat/ Km, suggested that full length protein had lower affinity for potential substrates and lower catalytic activity compared to the catalytic domain alone. These data suggested the importance of USP32 tertiary structure and possible role of other non DUB domains (e.g. EF hand domain) which may be regulated by an as of unknown mechanism in cells. Further investigations are underway to understand the functions of USP32 in cells and how it may contribute to breast tumorigenesis.

Synthetic CpG containing oligodeoxynucleotides (ODNs) are recognized by Toll like Receptor 9 (TLR9) and induce a strong pro-inflamatory immune response. To date, four different CpG ODN classes have been described. K-Class ODNs (also known as B-ODN) are potent B cell activators and stimulate TNF

Bacteria, nanoflagellates and ciliates constitute the microbial loop and it is a model of the pathways of carbon and nutrient cycling through microbial components of pelagic aquatic communities. The current study comprised of a comparative study of the microbial food web community along north to south latitudinal gradient using space for time susbtitute, monitoring and mesocosms experiments with contrasting nutrient and predation states. We investigated effect of fish predation through different zooplankton taxa on microbial loop community with in situ food web experiments in 14 lakes along north to south latitudinal gradient. The effect of seasonality was also determined by monitoring in Lakes Eymir and Mogan between 2010 and 2011. Effects of hydrology and fish through microbial community was studied in mesocosms in Lake Eymir. An implication of global warming along with eutrophication on microbial community was further explored in warmed and nutrient enriched artificial ponds during 4 months in Silkeborg, Denmark. Our results revealed that temperature, hydrology, fish, macrophytes and seasonality affected the top down control of zooplankton and bottom up control of nutrients on microbial loop and interactions between controls and increase in these controls had a strong negative impact on the contribution and biomass of microbial loop and change the interactions within microbial community. Global warming may also effect the impact of top down and bottom up controls through increasing eutrophication, temperature, change in hydrology and zooplankton composition and in a consequence of that efficiency of microbial loop may decrease in the future warmer, drier and eutrophic conditions.

In an earlier project completed in our laboratory a seasonal fluctuation in Phosphoglucomutase (PGM) phenotype frequencies was found, so that the winter bees were almost all heterozygotes and long lived than the summer bees among which homozygotes were significantly at high frequencies at Pgm locus. Same results were obtained in populations of three subspecies, A. m. meda, A. m. caucasica, and A. m. carnica from different climatic regions. In the current study environmental cues related with seasonal change in PGM phenotype frequency was examined along with the correlation between PGM heterozygosity and overwintering success. Cessation of food influx was found to be effective by itself as an environmental cue that causes a sudden and sharp increase in PGM heterozygosity. In addition to that, PGM heterozygosity of the colonies with greater overwintering success was found to be significantly higher than the ones with intermediate or low overwintering success. Benefiting from the previous studies and the results of current study, ethyl oleate was suggested as a chemical signal that functions in the regulation of PGM heterozygosity.

Cornea is the transparent outermost layer of the eye. It is a thin (500 &micro / m) multilayer tissue which performes around 75% of the total refraction in the eye. It also protects the inner layers against any type of damage. Since it is avascular, the three cellular layers of cornea always need transport of nutrients and other materials in and out of the tissue via diffusion. Any change in shape, transparency or thickness of cornea, or physical damages and infections, may cause serious defects. The conventional methods are satisfactory in the treatment of mild injuries but severe cases require the substitution of the tissue with an equivalent. Keratoprosthesis and donor corneas that are used as replacements do not completely meet requirements. Tissue engineering can be an alternative method for preparing a biocompatible and stable cornea equivalent. The ability to choose from a variety of materials and the ability to incorporate bioactive agents allow the researchers to tailor make the construct. The structure needs to be seeded with the patient&rsquo / s own cells and cultured in vitro to yield an optimal corneal replacement. In this study a novel, split thickness cornea replacement is proposed to substitute the two upper cellular layers (epithelium and stroma) of the native cornea. The design includes a chondroitin sulfate impregnated collagen type I (isolated from rat tail) foam (CSXLF) produced by lyophilization carrying electrospun fibers of the same polymer collected directly on top of the foam, forming the bilayer structure (Fo-Fi). The fiber layer was intended to separate the epithelium and the stroma of the reconstructed cornea yet to allow material transfer in between. The foam layer (bottom) was crosslinked by N-ethyl-N-[3-dimethylaminopropyl] carbodiimide (EDC), and N-hydroxy succinimide and after fiber deposition the bilayer was further stabilized with physical crosslinking (DHT method). The physical characterization of the foam showed that their pore sizes (10-200 &micro / m) and porosities (around 70%) were well within the desired range for typical tissue engineering applications. The cell free wet thicknesses of both single and bilayer constructs were close to that of the native stroma and light transmittance through these scaffolds was quite high (around 82% in the 500-700 nm range). The scaffolds were also tested for their stability and shown to be suitable for in vitro testing. In vitro studies were performed using retinal pigment epithelial cells (RPE, D407 cell line) and isolated human corneal keratocytes (HK) to reconstruct the epithelium and the stroma, respectively. Three types of constructs were prepared / only HK seeded Fo-Fi constructs, RPE-HK seeded CSXLFs, and RPE-HK seeded Fo-Fi constructs. All were shown to support cell attachment and promoted cell proliferation as was shown by the cells that covered the inner and outer spaces of the scaffolds. The fiber layer prevented the mixing of the two cell types, without hindering material exchange between them. Moreover, when co-cultured for 14 days, the keratocytes started to deposit collagen type I, a specific marker of these cells. In contrast, ECM deposition could not be observed in the single type cell seeded samples. The co-cultured bilayer construct was tested for suturability at the end of 31 days of in vitro incubation and it was shown that it could be successfully sutured without any major tears. Under the light of these results it was concluded that both the single layer and the bilayer constructs show promise for use as split thickness cornea replacements.

NMDA (N-methyl D-aspartate) Receptor is a ligand and voltage gated ion channel and involved in many processes such as synaptic plasticity, memory formation, behavioral responses and cell survival. In the sense of functional activity, cellular localization of NMDAR is important since this receptor shows its activity on the membrane. Although NMDA receptor is intensely studied there are no satisfying study showing its localization with microscobic methods. Besides, the effect of florescent protein labelling of NMDA receptor on its distribution is not shown. It is expected to provide basis for further interaction and distribution studies with this comparison. Contrary to literature, in this study it is shown that NMDA receptor does not localize only in ER and membrane instead has a cytosolic pattern and this pattern is compatible with the distribution of wild type NMDA receptor. In addition, florescent protein labelling of NMDA receptor does not interrupt cellular distribution of NMDAR. Moreover, this study shows that N-terminal domain of NR1 subunit is sufficient to prevent degradation of NR2B in the cell. In consideration of this study it can be concluded that EGFP and mCherry labelled NMDA receptors can be used in interaction studies such as FRET and other studies, making use of fluorescent labelling of NMDA receptors, in terms of cellular distribution.