Precision Microstate Counting of Small Black Rings

We examine certain two-charge supersymmetric states with spin in five-dimensional string theories which can be viewed as small black rings when the gravitational coupling is large. Using the 4D-5D connection, these small black rings correspond to four-dimensional non-spinning small black holes. Using this correspondence, we compute the degeneracy of the microstates of the small black rings exactly and show that it is in precise agreement with the macroscopic degeneracy to all orders in an asymptotic expansion. Furthermore, we analyze the five-dimensional small black ring geometry and show qualitatively that the Regge bound arises from the requirement that closed time-like curves be absent.Comment: 4 pages, LaTeX, references adde

Biodiesel Production from Mixed Culture Algae Via a Wet Lipid Extraction Procedure

With world crude oil reserves decreasing and energy prices continually increasing, interest in developing renewable alternatives to petroleum-based liquid fuels has increased. An alternative that has received consideration is the growth and harvest of microalgae for the production of biodiesel via extraction of the microalgal oil or lipids. However, costs related to the growth, harvesting and dewatering, and processing of algal biomass have limited commercial scale production of algal biodiesel. Coupling wastewater remediation to microalgal growth can lower costs associated with large scale growth of microalgae. Microalgae are capable of assimilating inorganic nitrogen and phosphorous from wastewater into the biomass. By harvesting the microalgal biomass these nutrients can be removed, thus remediating the wastewater. Standard methods of oil extraction require drying the harvested biomass, adding significant energetic cost to processing the algal biomass. Extracting algal lipids from wet microalgal biomass using traditional methods leads to drastic reductions in extraction efficiency, driving up processing costs. A wet lipid extraction procedure was developed that was capable of extracting 79% of the transesterifiable lipids from wet algal biomass (16% solids) without the use of organic solvents while using relatively mild conditions (90 °C and ambient pressures). Ultimately 77% of the extracted lipids were collected for biodiesel production. Furthermore, the procedure was capable of precipitating chlorophyll, allowing for the collection of algal lipids independently of chlorophyll. The capability of this procedure to extract lipids from wet algal biomass, to reduce chlorophyll contamination of the algal oil, and to generate feedstock material for the production of additional bio-products provides the basis for reducing scale-up costs associated with the production of algal biofuels and bioproducts

Identifying alterations in adipose tissue-derived islet GPCR peptide ligand mRNAs in obesity: implications for islet function

In addition to acting as an energy reservoir, white adipose tissue is a vital endocrine organ involved in the modulation of cellular function and the maintenance of metabolic homeostasis through the synthesis and secretion of peptides, known as adipokines. It is known that some of these secretory peptides play important regulatory roles in glycaemic control by acting directly on islet β-cells or on insulin-sensitive tissues. Excess adiposity causes alterations in the circulating levels of some adipokines which, depending on their mode of action, can have pro-inflammatory, pro-diabetic or anti-inflammatory, anti-diabetic properties. Some adipokines that are known to act at β-cells have actions that are transduced by binding to G protein- coupled receptors (GPCRs). This large family of receptors represents ~35% of all current drug targets for the treatment of a wide range of diseases, including type 2 diabetes (T2D). Islets express ~300 GPCRs, yet only one islet GPCR is currently directly targeted for T2D treatment. This deficit represents a therapeutic gap that could be filled by the identification of adipose tissue-derived islet GPCR peptide ligands that increase insulin secretion and overall β-cell function. Thus, by defining their mechanisms of action, there is potential for the development of new pharmacotherapies for T2D. Therefore, this thesis describes experiments which aimed to compare the expression profiles of adipose tissue-derived islet GPCR peptide ligand mRNAs under lean and obese conditions, and to characterise the functional effects of a selected candidate of interest on islet cells. Visceral fat depots were retrieved from high-fat diet-induced and genetically obese mouse models, and from human participants. Fat pads were either processed as whole tissue, or mature adipocyte cells were separated from the stromal vascular fraction (SVF) which contains several other cell populations, including preadipocytes and macrophages. The expression levels of 155 islet GPCR peptide ligand mRNAs in whole adipose tissue or in isolated mature adipocytes were quantified using optimised RNA extraction and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) protocols. Comparisons between lean and obese states in mice models and humans revealed significant modifications in the expression levels of several adipokine mRNAs. As expected, mRNAs encoding the positive control genes, Lep and AdipoQ were quantifiable, with the expression of Lep mRNA increasing and that of AdipoQ mRNA decreasing in obesity. Expression of Ccl4 mRNA, encoding chemokine (C-C motif) ligand 4, was significantly upregulated in whole adipose tissue across all models of obesity compared to their lean counterparts. This coincided with elevated circulating Ccl4 peptide levels. This increase was not replicated in isolated mature adipocytes, indicating that the source of upregulated Ccl4 expression in obesity was the SVF of adipose tissue. Based on this significant increase in Ccl4 mRNA expression within visceral fat and its undetermined effects on β-cell function, Ccl4 was selected for further investigation in MIN6 β-cells and mouse islets. PRESTO-Tango β-arrestin reporter assays were performed to determine which GPCRs were activated by exogenous Ccl4. Experiments using HTLA cells expressing a protease-tagged β- arrestin and transfected with GPCR plasmids of interest indicated that 100ng/mL Ccl4 significantly activated Cxcr1 and Cxcr5, but it was not an agonist at the previously identified Ccl4-target GPCRs Ccr1, Ccr2, Ccr5, Ccr9 and Ackr2. RNA extraction and RT-qPCR experiments using MIN6 β-cells and primary islets from lean mice revealed the expression of Cxcr5 mRNA in mouse islets, but it was absent in MIN6 β-cells. The remaining putative Ccl4 receptors (Ccr1, Ccr2, Ccr5, Ccr9, Cxcr1 and Ackr2) were either absent or present at trace levels in mouse islets and MIN6 β-cells. Recombinant mouse Ccl4 protein was used for functional experiments at concentrations of 5, 10, 50 and 100ng/mL, based on previous reports of biological activities at these concentrations. Trypan blue exclusion testing was initially performed to assess the effect of exogenous Ccl4 on MIN6 β-cell viability and these experiments indicated that all concentrations (5-100ng/mL) were well-tolerated. Since β-cells have a low basal rate of apoptosis, cell death was induced by exposure to the saturated free fatty acid, palmitate, or by a cocktail of pro-inflammatory cytokines (interleukin-1β, tumour necrosis factor-α and interferon-γ). In MIN6 β-cells, Ccl4 demonstrated concentration-dependent protective effects against palmitate-induced and cytokine-induced apoptosis. Conversely, while palmitate and cytokines also increased apoptosis of mouse islets, Ccl4 did not protect islets from either inducer. Quantification of bromodeoxyuridine (BrdU) incorporation into β-cell DNA indicated that Ccl4 caused a concentration-dependent reduction in proliferation of MIN6 β-cells in response to 10% fetal bovine serum (FBS). In contrast, immunohistochemical quantification of Ki67-positive mouse islet β-cells showed no differences in β-cell proliferation between control- and Ccl4-treated islets. Whilst the number of β-cells and δ-cells were unaffected, α- cells were significantly depleted by Ccl4 treatment. Exogenous Ccl4 had no effect on nutrient- stimulated insulin secretion from both MIN6 β-cells and primary mouse islets. The 3T3-L1 preadipocyte cell line was used to assess potential Ccl4-mediated paracrine and/or autocrine signalling within adipose tissue. Ccl4 did not alter the mRNA expression of Pparγ, a master regulator of adipocyte differentiation, but did significantly downregulate the mRNA expression of the crucial adipogenic gene, adiponectin. Oil Red O staining and Western blotting were performed to assess lipid accumulation, and insulin and lipolytic signalling, respectively, and these experiments indicated that the observed Ccl4-induced decrease in adiponectin expression failed to correlate with any changes in adipocyte function. In summary, these data demonstrated anti-apoptotic and anti-proliferative actions of the adipokine, Ccl4, on MIN6 β-cells that were not replicated in mouse islets. The absence of any anti-apoptotic, insulin secretory and/or pro-proliferative effects of Ccl4 in islet β-cells suggests that it is unlikely to play a role in regulating β-cell function via crosstalk between adipose tissue and islets. The divergent functional effects highlight that whilst MIN6 cells are a useful primary β-cell surrogate for some studies, primary islets should always be used to confirm physiological relevance. On the other hand, significant α-cell depletion following Ccl4 treatment suggests a cell-specific function within the islets. Furthermore, Ccl4 impaired adiponectin mRNA expression in adipocytes, although, how adipocyte function is affected as a result requires further investigation. Collectively, these data have contributed increased understanding of the role of obesity in modifying the expression of adipose tissue-derived islet GPCR peptide ligands

The use of Ethnomedicinal plants in Indigenous Health Care Practice of the Hajong Tribe community in Durgapur, Bangladesh

The Garo Hills have always been fascination to the naked human eyes. The hills are the shelter of the earliest human habitation of Bangladesh. It is a place of ancient cultures and many botanical wonders. It is situated in the most northern part of Durgapur sub-district having border with Meghalaya of India. Durgapur is rich with ethnic diversity with Hajong and Garo as the major ethnic groups along with some Bengali settlers from the common population. Present survey was undertaken to compile the medicinal plant usage among the Hajong Tribe of Durgapur

Issue Ownership And Framing Of Digital Privacy On Twitter

The issue ownership theory states political parties tend to emphasize the issues they are perceived to own in a bid to gain an advantage in public opinion. Although tested on different established political issues and in mass communicational settings, the theory has not been adequately tested for new and evolving political issues and on social media. This study attempts to test issue ownership theory and examine episodic and thematic media framing in Twitter conversations of US senators regarding the issue of digital privacy. Combination of computerized and manual content analysis is used to download and analyze all US senators’ tweets related to the issue. The results show marginal issue ownership effort by Republicans, and reverse issue ownership, also known as issue trespassing, effort by Democrats. The senators who were active about the issue in the Congress were also active on Twitter. The senators used comparatively more episodic framing in the beginning period and thematic framing in the middle period of the time frame. The results suggest senators, being a member of a deliberative political body, did not follow partisan rhetoric on digital privacy. On the other hand, the mass-personal nature of Twitter is related with the medium having comparatively little issue-owning cues. Future suggestions for issue ownership studies on social media settings and for non-partisan issues are discussed

Synergy between biology and systems resilience

Resilient systems have the ability to endure and successfully recover from disturbances by identifying problems and mobilizing the available resources to cope with the disturbance. Resiliency lets a system recover from disruptions, variations, and a degradation of expected working conditions. Biological systems are resilient. Immune systems are highly adaptive and scalable, with the ability to cope with multiple data sources, fuse information together, makes decisions, have multiple interacting agents, operate in a distributed manner over a multiple scales, and have a memory structure to facilitate learning. Ecosystems are resilient since they have the capacity to absorb disturbance and are able to tolerate the disturbances. Ants build colonies that are dispersed, modular, fine grained, and standardized in design, yet they manage to forage intelligently for food and also organize collective defenses by the property of resilience. Are there any rules that we can identify to explain the resilience in these systems? The answer is yes. In insect colonies, rules determine the division of labor and how individual insects act towards each other and respond to different environmental possibilities. It is possible to group these rules based on attributes. These attributes are distributability, redundancy, adaptability, flexibility, interoperability, and diversity. It is also possible to incorporate these rules into engineering systems in their design to make them resilient. It is also possible to develop a qualitative model to generate resilience heuristics for engineering system based on a given attribute. The rules seen in nature and those of an engineering system are integrated to incorporate the desired characteristics for system resilience. The qualitative model for systems resilience will be able to generate system resilience heuristics. This model is simple and it can be applied to any system by using attribute based heuristics that are domain dependent. It also provides basic foundation for building computational models for designing resilient system architectures. This model was tested on recent catastrophes like the Mumbai terror attack and hurricane Katrina. With the disturbances surrounding the current world this resilience model based on heuristics will help a system to deal with crisis and still function in the best way possible by depending mainly on internal variables within the system --Abstract, page iii

A Demonstration Study of Drainage Water Management in Eastern South Dakota

Subsurface drainage is a common water management practice for improving crop production in poorly drained soils; however, the practice is associated with several environmental concerns such as nutrient losses to downstream surface waters. These environmental concerns from subsurface drainage have prompted interest in drainage water management strategies such as controlled drainage. This study assessed the agronomic and environmental impacts of drainage water management in eastern South Dakota by using two demonstration plots for controlled and conventional drainage. Drain flow, nitrate and dissolved phosphorous concentration in drain water, shallow groundwater, crop yield, residual soil nitrate, soil moisture and temperature, soil penetration resistance, bulk density, soil pH, and leaf area index (LAI) were measured from 2014 to 2016 from the two adjacent drainage plots. Soybean, oats, and corn were planted in 2014, 2015, and 2016, respectively with urea fertilizer applied during the corn year. Results showed that controlled drainage reduced drain flow by 58% compared to conventional drainage. Nitrate concentration in drain water increased and exceeded maximum contaminant level (10 mg/L) for drinking water in both controlled and conventional drainage plots during the second project year. Annual nitrate load was reduced by 55% with controlled drainage compared to conventional drainage. Nitrate concentration in shallow groundwater was slightly higher in the conventional drainage plot than in the controlled drainage plot, and generally higher than 10 mg/L for both plots. Dissolved phosphorous concentration in drain water and shallow groundwater exceeded the critical level of 0.03 mg/L for freshwater eutrophication. The dissolved phosphorous concentration in drain water was higher in controlled drainage compared to conventional drainage; but significantly higher in conventional drainage compared to controlled drainage in shallow groundwater samples (p \u3c 0.05). Unlike nitrate load, controlled drainage increased dissolved phosphorous load by 35% compared to conventional drainage. Shallow groundwater table was significantly higher in the controlled drainage plot than in the conventional drainage plot. The soil moisture content near the outlet and middle of plots was higher in the conventional drainage plot than in the controlled drainage plot at all depths, except for 20 cm depth in the middle of controlled drainage plot and 105 cm depth near the plot outlet in the conventional drainage plot. Soil temperature and penetration resistance showed no statistical difference in mean between the controlled and conventional drainage plots. However, the controlled drainage plot had slightly higher soil temperature than the conventional drainage plot, and slightly higher soil penetration resistance was measured in the conventional drainage plot. Mean residual soil nitrate content in the controlled drainage plot was significantly higher than in the conventional drainage plot. Controlled drainage showed 8% less yield for soybean, and 9% less yield for corn, while 5% increase in yield for oats was observed in controlled drainage compared to conventional drainage. Comparison of LAI between the controlled and conventional drainage plots was statistically not significant. However, the controlled drainage plot had slightly higher LAI than the conventional drainage plot