Microplastics in Fiddler Crabs (genus Uca)

Microplastics, as defined by NOAA, are small plastic pieces less than five millimeters long, which cannot be seen with the naked eye. The production of plastic products and plastic use has exponentially increased since the start of plastic usage. Consequently, the amount of plastic waste has also increased greatly. Plastic waste that has been thrown out by humans into the environment breaks down into microscopic pieces, causing harm to organisms that live there. The purpose of this study was to see if there were microplastics passing through fiddler crabs (genus Uca), collected from the marsh at Waties Island, SC. Fecal samples from the crabs were teased apart and examined under a microscope to quantify the number and the types of microplastics present. Microplastics were found in almost every sample taken, indicating that microplastics are present in even in this relatively pristine environment. The effects of the intake of microplastics on fiddler crab survival and reproductive fitness will have profound impacts on other organisms through predation and other processes, since fiddler crabs are an important low trophic organism at Waties Island, SC

The effects of human approach on sanderling foraging behavior

During low tide, sanderlings (Calidris alba) forage on small invertebrates in the sand of the intertidal zone. As a result, these common shorebirds frequently come into contact with humans who visit the beaches for a variety of activities, such as fishing or jogging. Here, the effects of three different approach types (undisturbed, passive, and aggressive) on sanderling foraging behavior were examined to help understand how human activities may be affecting their ability to search for food. At two local beaches, locomotory rate was recorded in addition to obvious changes in initial behavior. Treatments were defined as follows: 1) Undisturbed – sanderlings observed from a distance that does not influence their behavior 2) Passive - a human approached by walking at a steady walking pace from a predetermined distance 3) Aggressive - a more assertive approach at a noticeably faster speed from a closer distance. In general, sanderlings exposed to an aggressive approach moved at the highest rate, while the rates of birds approached passively or not at all did not differ significantly from each other. This was true for birds found at both locations. These results show a correlation between intensity of human approach and sanderling response, potentially impeding their ability to forage. The similarities between sites suggest that sanderling populations move frequently between local beaches and are therefore likely to show similar responses to the presence of humans regardless of beach location

Total RNA Analysis of Bacterial Community Structural and Functional Shifts Throughout Vertebrate Decomposition

Multiple methods have been proposed to provide accurate time since death estimations, and recently, the discovery of bacterial community turnover during decomposition has shown itself to have predictable patterns that may prove useful. In this study, we demonstrate the use of metatranscriptomics from the postmortem microbiome to simultaneously obtain community structure and functional data across postmortem intervals (PMIs). We found that bacterial succession patterns reveal similar trends as detected through DNA analysis, such as increasing Clostridiaceae as decomposition occurs, strengthening the reliability of total RNA community analyses. We also provide one of the first analyses of RNA transcripts to characterize bacterial metabolic pathways during decomposition. We found distinct pathways, such as amino acid metabolism, to be strongly up‐regulated with increasing PMIs. Elucidating the metabolic activity of postmortem microbial communities provides the first steps to discovering postmortem functional biomarkers since functional redundancy across bacteria may reduce host individual microbiome variability.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152033/1/jfo14083_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152033/2/jfo14083.pd

Bacterial Community Succession, Transmigration, and Differential Gene Transcription in a Controlled Vertebrate Decomposition Model

Decomposing remains are a nutrient-rich ecosystem undergoing constant change due to cell breakdown and abiotic fluxes, such as pH level and oxygen availability. These environmental fluxes affect bacterial communities who respond in a predictive manner associated with the time since organismal death, or the postmortem interval (PMI). Profiles of microbial taxonomic turnover and transmigration are currently being studied in decomposition ecology, and in the field of forensic microbiology as indicators of the PMI. We monitored bacterial community structural and functional changes taking place during decomposition of the intestines, bone marrow, lungs, and heart in a highly controlled murine model. We found that organs presumed to be sterile during life are colonized by Clostridium during later decomposition as the fluids from internal organs begin to emulsify within the body cavity. During colonization of previously sterile sites, gene transcripts for multiple metabolism pathways were highly abundant, while transcripts associated with stress response and dormancy increased as decomposition progressed. We found our model strengthens known bacterial taxonomic succession data after host death. This study is one of the first to provide data of expressed bacterial community genes, alongside transmigration and structural changes of microbial species during laboratory controlled vertebrate decomposition. This is an important dataset for studying the effects of the environment on bacterial communities in an effort to determine which bacterial species and which bacterial functional pathways, such as amino acid metabolism, provide key changes during stages of decomposition that relate to the PMI. Finding unique PMI species or functions can be useful for determining time since death in forensic investigations

Proposals for the Future of Leadership Scholarship:Suggestions in Phronesis

“Phronesis” can be summarized as “wisdom in determining ends and the means of attaining them.” This unique article originated from comments made by scholars on a podcast hosted by Dr. Scott Allen titled “Phronesis: Practical Wisdom for Leaders.” Here, we propose ten specific agendas focused on the future of scholarship in the field of leadership studies, authored by some of these scholars. Topics include how to think about effective leadership in “the age of emotion” where truth can seem up for debate; specific topical suggestions for expanded study–such as more comprehensively studying place and space, indigenous wisdom, equity issues, games that teach, and focusing more on lifespan perspectives; better integrating scholarship with professional settings where leading occurs; and more effectively framing what it even means to lead and follow

Response to Conspecific Chemical Cues in the Fiddler Crab Uca Rapax

Fiddler crabs are well-known for their visual displays in courtship and social interactions. However, the ability of these animals to produce and respond to chemical stimuli remains unknown. The current study investigated the existence of these cues and the information they may contain. Experiments were designed to discover any behavioral differences among populations as well as the duration of the cues. Both male and female crabs were found to be able to distinguish the size and sex of another fiddler crab by chemical cues alone, and displayed preferences for sand exposed to females and smaller crabs. Mate choice trials were conducted using crabs from a local and non-local population to determine whether these chemical cues differ among populations. Females showed a preference for males from a non-local population based on chemical cues. Larval development was studied to ascertain the duration of the planktonic larval phase as well as gain information regarding survival and development rates correlated with factors such as mother size, hatch date, and hatch size. Larval survival and duration were found to be impacted by the timing of release and the size of the mother. Population genetic analyses using cytochrome oxidase I were conducted to discover the relatedness of different populations of fiddler crabs throughout the Gulf of Mexico. Populations from Texas showed high relatedness, which may indicate high gene flow among populations

Detection of critical antibiotic resistance genes through routine microbiome surveillance.

Population-based public health data on antibiotic resistance gene carriage is poorly surveyed. Research of the human microbiome as an antibiotic resistance reservoir has primarily focused on gut associated microbial communities, but data have shown more widespread microbial colonization across organs than originally believed, with organs previously considered as sterile being colonized. Our study demonstrates the utility of postmortem microbiome sampling during routine autopsy as a method to survey antibiotic resistance carriage in a general population. Postmortem microbial sampling detected pathogens of public health concern including genes for multidrug efflux pumps, carbapenem, methicillin, vancomycin, and polymixin resistances. Results suggest that postmortem assessments of host-associated microbial communities are useful in acquiring community specific data while reducing selective-participant biases

Scientific Basis for Sustainable Management of Eucalyptus and Populus as Short-Rotation Woody Crops in the U.S.

Short rotation woody crops (SRWC), fast growing tree species that are harvested on short, repeated intervals, can augment traditional fiber sources. These crops have economic and environmental benefits stemming from their capability of supplying fiber on a reduced land base in close proximity to users and when sensitive sites cannot be accessed. Eucalyptus and Populus appear to be genera with the greatest potential to provide supplemental fiber in the U.S. Optimal productivity can be achieved through practices that overcome site limitations and by choosing the most appropriate sites, species, and clones. Some Eucalyptus species are potentially invasive, yet field studies across multiple continents suggest they are slower to disperse than predicted by risk assessments. Some studies have found lower plant and animal diversity in SRWC systems compared to mature, native forests, but greater than some alterative land uses and strongly influenced by stand management, land use history, and landscape context. Eucalyptus established in place of grasslands, arable lands, and, in some cases, native forests can reduce streamflow and lower water tables due to higher interception and transpiration rates but results vary widely, are scale dependent, and are most evident in drier regions