6,717 research outputs found
Measuring Charge Carrier Mobility of Graphene
This research reports measurements of electron mobility in liquid-gated graphene. Graphene field-effect transistor (GFET) biosensors are more sensitive to changes in external fields when the mobility is high; therefore increasing mobility will improve sensitivity. Mobility can be calculated from the ratio of sheet conductivity to carrier density. Sheet conductivity was measured using van der Pauw geometry and carrier density was determined from measurements of the liquid-gate capacitance. It is shown that mobility improves after the graphene surface is cleaned by an annealing process
Effects of processes at the population and community level on carbon dynamics of an ecosystem model
Ecological processes at the population and community level are often ignored in biogeochemical models, however, the effects of excluding these processes at the ecosystem level is uncertain. In this study we analyzed the set of behaviors that emerge after introducing population and community processes into an ecosystem carbon model. We used STANDCARB, a hybrid model that incorporates population, community, and ecosystem processes to predict carbon dynamics over time. Our simulations showed that at the population level, colonization and mortality rates can limit the maximum biomass achieved during a successional sequence. Specifically, colonization rates control temporal lags in the initiation of carbon accumulation, and mortality rates can have important effects on annual variation in live biomass. At the community level, differences in species traits and changes in species composition over time introduced significant changes in carbon dynamics. Species with different set of parameters, such as growth and mortality rates, introduce patterns of carbon accumulation that could not be reproduced using a single species with the average of parameters of multiple species or by simulating the most abundant species (strategies commonly employed in terrestrial biogeochemical models). We conclude that omitting population and community processes from biogeochemical models introduces an important source of uncertainty that can impose important limitations for predictions of future carbon balances
Oral History Interview: James A. Harmon
James A. Harmon was born in 1890 on his grandfather’s farm outside of Red House, WV. Mr. Harmon reminiscences about his childhood growing up on a 350-acre farm. He earned a sixth grade education at a two-room schoolhouse. When he was 14 years old, Mr. Harmon started his career on the river on the Steamer Calvert. During his interview, Mr. Harmon focuses on his varied jobs on many steamboats. Although he performed well in all of his duties, his greatest passion was engineering. He received his engineer’s license when he was 21 years old. In the audio clip provided, Mr. Harmon discusses life on the river, with an emphasis on the boats and jobs he held while employed.https://mds.marshall.edu/oral_history/1010/thumbnail.jp
Three-Dimensional Plasma Cell Survival Microniche in Multiple Myeloma
Multiple myeloma (MM) is an incurable malignancy characterized by the uncontrolled proliferation of long-lived plasma cells (PCs) in the bone marrow (BM), which constitute at least 10% of BM cellularity. Normally, long-lived plasma cells make up less than 1% of BM cells. Plasma cells become neoplastic when a clonal PC population produces a monoclonal immunoglobulin protein. A diagnosis of monoclonal gammopathy of undetermined significance (MGUS) is made when there is an increase in monoclonal PCs within the BM, but less than 10%, and the patient does not present with end-organ damage, which is associated with active MM. Though not considered pathological at this stage, individuals with MGUS are at an increased risk for developing MM. There are several challenging aspects in treating MM including the high clonal heterogeneity of MM cells and its clinical repercussions, thus making the malignancy difficult to treat. Further heterogeneity is found in regard to disease onset, disease progression, therapeutic resistance, and subsequent patient relapse.
The purpose of this project is to investigate the microniche of PCs as they transition from premalignant to malignant myeloma cells in order to provide valuable insight which can be exploited to test current and novel therapeutic treatments. This project has demonstrated changes in the expression of fibronectin and morphological differences in plasma cells within core biopsies, which may support disease progression. Additionally, the purpose of this project is also to generate a long-term 3D in vitro culture models of MM using a high-throughput hydrogel platform. By using BM aspirates from MGUS and MM patients, results demonstrated that this 3D culturing system is capable of reproducing key features on long-lived PCs. Furthermore, these BM cultures maintained their abnormal phenotypes for at least five days of culture. This extended timeframe allows for better characterization of the mechanisms of action of current therapies and testing of emerging treatments for this incurable disease
The Problem of Policing
The legal problem of policing is how to regulate police authority to permit officers to enforce law while also protecting individual liberty and minimizing the social costs the police impose. Courts and commentators have largely treated the problem of policing as limited to preventing violations of constitutional rights and its solution as the judicial definition and enforcement of those rights. But constitutional law and courts alone are necessarily inadequate to regulate the police. Constitutional law does not protect important interests below the constitutional threshold or effectively address the distributional impacts of law enforcement activities. Nor can the judiciary adequately assess law enforcement practices or predict police conduct. The problem of policing is fundamentally a problem of regulation-a fact largely invisible in contemporary scholarship. While scholars have criticized the conventional paradigm, contemporary scholarship continues to operate within its limits. In this Article, I advocate a new agenda for scholars considering the police, one that asks not how the Constitution constrains the police but how law and public policy can best regulate the police. First, scholars should evaluate policing practices to determine what harms they produce, which practices are too harmful, and which are harm efficient. These inquiries are essential to ensuring that the benefits of policing are worth the costs it imposes. Second, scholars should explore the full law of the police -the web of interacting federal, state, and local laws that govern the police and police departments. Presently, for example, courts tailor their interpretation of § 1983 and the exclusionary rule to encourage changes in police behavior yet civil service law, collective bargaining law, and federal and state employment discrimination law simultaneously discourage the same reforms, a phenomenon ignored by the academy. Third, scholars should analyze the capacities and incentives of nonjudicial local, state, and federal institutions to contribute to a regulatory regime capable of intelligently choosing and efficiently promoting the best ends of policing. This agenda offers a path for moving beyond constitutional criminal procedure toward a legal regime that promotes policing that is both effective and protective of individual freedom
An Archeological Survey of a Realignment of the Proposed Wateree-Orangeburg 230 KV Transmission Line and an Archeological Testing Program for 38CL29, 38CL37 and 38CL41
https://scholarcommons.sc.edu/archanth_books/1169/thumbnail.jp
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