Dispersant Efficacy and Effectiveness

Dispersants have been researched extensively and used for oil spill mitigation for more than 40 years, yet there are opportunities to enhance our understanding, including with respect to their long term fate and effects and how to optimize dispersant use. For example, the 2005 National Academy of Sciences report, Understanding Oil Spill Dispersants: Efficacy and Effects, suggested a number of areas where increased understanding would help support the use of dispersants. Throughout the summer of 2010 dispersants were used in unprecedented quantities and, in the case of sub-sea application, with novel application methods following the Deepwater Horizon incident. The focus of this paper is to provide a brief overview of spilled oil behavior, chemical dispersants efficacy and effectiveness, and a discussion of the state of knowledge pre-, during, and post- Deepwater Horizon

Postmodernism in the Contemporary Novel : Non-linear and Dyssynchronous Elements in the Narratives of The White Hotel, The Golden Notebook, and The French Lieutenant\u27s Woman

This paper seeks to examine theoretical aspects of the narrative by exploring the elements of time and structure that constitute selected novels of D.M. Thomas, Doris Lessing, and John Fowles. Specifically, this paper will explore the spatiotemporal aspects of the narrative, including the impact of chronological arrangement and structural organization on the formation of meaning. The novels examined in this paper-The White Hotel, The French Lieutenant\u27s Woman, and The Golden Notebook- challenge assumptions about the interpretation of narrative and the validity of the novel as commentary on the human condition. Each seeks new ways of narration and new ways to challenge form and tradition. Because these types of confrontation are consistent with a postmodern aesthetic, this paper will examine the theories of such postmodern thinkers as Roland Barthes, Jacques Derrida, and Jean Baudrillard. Doing so will provide background for its exploration into such issues as the use of pastiche by postmodern authors, the presentation of fragmented narratives, the confusion of narrative voice, and the overall challenge to authority that is a defining aspect of postmodernism. The overall purpose of this paper is to consider whether or not the disordered temporality, fragmented structure, confused narration, and oppositional stance of the postmodernism novel signals an abrogation of fictional narrative as a fundamental human activity and need

Microbial diversity and community structure in sediments associated with the Seagrass (Thallassia testudinum) in Apalachicola Bay, Florida

Seagrass is an angiosperm which provides many ecosystem services in coastal areas, such as providing food, shelter and nurseries for many species, and decreasing the impact of waves on shorelines. A global assessment reported that 29% of known seagrass meadows are in a state of decline due to the effects of human activity. Seagrass is commonly found in shallow marine waters where they form meadows containing a microbiome that plays an important role in providing nutrients for seagrass growth, though little is known about the microorganisms within the seagrass meadow sediments. Our project collected sediments from seagrass meadows and adjacent unvegetated areas around Apalachicola Bay, Florida. We sequenced the bacterial communities present and compared the communities, which provided data that indicated that the differences in bacterial communities were primarily between sites and that vegetated and unvegetated plots within the same collection site were similar

Guano among bat species from two regions shows influence of geography and diet on bacterial community

Studies of bat guano have shown that the diversity and structure of associated microbial communities can be related to factors such as host phylogeny, life history and reproductive stage, geography, and diet. Many insectivorous bat species in the southeastern U.S. have generalist diets that may shift seasonally to take advantage of abundant prey species or maximize caloric intake. Seasonal shifts in prey availability or consumption should be reflected in a guano microbiome change. We also expected to detect distinct guano microbiomes within species. Within species, distinct microbial communities related to geography, and finally life history and reproductive stage. We compared the bacterial communities in bat guano collected directly from five species and two regions of the USA. Guano was collected opportunistically during netting events from May to October from the Appalachian foothills (Rome, GA), and the coastal plain (Bluffton, SC). DNA was extracted from 160 samples. DNA elutions were pooled for samples based on collection time and species ID. We sequenced the 16S rDNA barcode regions (V3, V4). Qiime2 was used to filter reads and assign taxonomy (green genes reference classifier). The bacterial community detected in the Rome samples showed a seasonal shift related to diet shift in big brown bat and red bat samples. Samples from Rome had greater bacterial diversity among species; whereas, samples from Palmetto Bluff were more similar to each other. Overall geography and diet were important factors related to the diversity and structure of the guano bacterial community

A State University’s Assessment of ACUE: Feasible Model for Evaluating the Impact of a Faculty Instruction Quality Program

State comprehensive universities often stress the development of teaching quality to improve the outcomes and retention of students, especially for recently matriculated students. These universities invest in teaching quality programs, but often lack a feasible method to examine the longitudinal impacts of these programs. The purpose of this paper is to provide a model for universities to evaluate outcomes related teaching quality programs. ACUE, a teaching quality program, was implemented across 30 instructors, which equated to 463 course sections. ACUE instructors were matched to non-ACUE instructors using propensity score matching (PSM) and compared on the rate of end-of-the-semester students with DFW (underperformance) standing across course sections. PSM was based on if courses were honors sections, lower level classes, size of enrollment in the sections, and if the section occurred after the completion of the program. DFW rate is a parsimonious metric that predict retention. The ACUE recipients had an average treatment effect of -.37, or 3.7% fewer students receiving a DFW. That translated to 171 fewer DFW grades. Implications include that the use of PSM and DFW rates could help universities examine longitudinal outcomes for teaching quality programs. Given the financial and personnel resources needed for program like ACUE, comprehensive regional universities could use similar methods to determine if the investment yields satisfactory returns

Microscopic evidence for strong periodic lattice distortion in 2D charge-density wave systems

In the quasi-2D electron systems of the layered transition metal dichalcogenides (TMD) there is still a controversy about the nature of the transitions to charge-density wave (CDW) phases, i.e. whether they are described by a Peierls-type mechanism or by a lattice-driven model. By performing scanning tunneling microscopy (STM) experiments on the canonical TMD-CDW systems, we have imaged the electronic modulation and the lattice distortion separately in 2H-TaS$_2$, TaSe$_2$, and NbSe$_2$. Across the three materials, we found dominant lattice contributions instead of the electronic modulation expected from Peierls transitions, in contrast to the CDW states that show the hallmark of contrast inversion between filled and empty states. Our results imply that the periodic lattice distortion (PLD) plays a vital role in the formation of CDW phases in the TMDs and illustrate the importance of taking into account the more complicated lattice degree of freedom when studying correlated electron systems

Evaluation of Chelating Agents Used in Phytoextraction by Switchgrass of Lead Contaminated Soil

Soil lead (Pb) contamination is a recognized environmental and global health problem. Phytoextraction of Pb using switchgrass (Panicum virgatum L.), a second-generation biofuel crop, is typically enhanced by soil chelation. The effectiveness of four different chelating agents, phytic acid (inositol hexaphosphate), citric acid, NTA (nitrilotriacetic acid), and EDTA (ethylenediaminetetraacetic acid) was examined in pot culture. Plants treated with EDTA (1 mM) showed significantly higher shoot Pb concentrations compared to control plants and plants treated with other chelates. Lead-solubility following phytoextraction was examined by soil washing using 0.01 and 0.05 M acetic acid as an extractant solution revealed no significant differences in Pb concentrations in soil among different chelate treatments and control. Furthermore, the effects of different concentrations (1, 2, 5 and 10 mM) of NTA on Pb phytoextraction of switchgrass were examined. Plants receiving 5 mM and 10 mM NTA had significantly higher foliage concentrations of Pb compared to plants treated with lower levels (1 and 2 mM) of NTA. Moreover, the effect of NTA application alone was significantly improved by a combined application of Triton X-100, an alkyl polyglucoside (APG); the Pb concentration in the foliage of switchgrass was more than doubled when treated with NTA combined with APG. The use of NTA combined with APG has great potential in improving phytoextraction efficiencies of switchgrass on Pb-contaminated soils