Beyond Megalopolis: Exploring America’s New “Megapolitan” Geography

The Metropolitan Institute at Virginia Tech identifies ten US “Megapolitan Areas”— clustered networks of metropolitan areas that exceed 10 million total residents (or will pass that mark by 2040) . Six Megapolitan Areas lie in the eastern half of the United States, while four more are found in the West. Megapolitan Areas extend into 35 states, including every state east of the Mississippi River except Vermont. Sixty percent of the Census Bureau’s “Consolidated Statistical Areas” are found in Megapolitan Areas, as are 39 of the nation’s 50 most populous metropolitan areas. As of 2003, Megapolitan Areas contained less than a fifth of all land area in the lower 48 states, but captured more than two-thirds of total US population with almost 200 million people. Megapolitan Areas are expected to add 83 million people (or the current population of Germany) by 2040, accounting for seven in every ten new Americans. By 2040, a projected 33 trillion dollars will be spent on Megapolitan building construction. The figure represents over three quarters of all the capital that will be expended nationally on private real estate development. In 2004, Democratic candidate John Kerry won the Megapolitan Area popular vote by 51.6 percent to 48.4 for President George W. Bush—or almost the exact reverse of the nation as a whole. Kerry received 46.4 million Megapolitan votes, while Bush won 43.5 million. Megapolitan geography reframes many planning and public policy debates, touching on such issues as environmental impact, transportation, and urban sprawl

Deconstructing woronin body formation

Master'sMASTER OF SCIENC

A Comparison of Microstructure and Uniaxial Compressive Response of Ice-Templated Porous Alumina Scaffolds Fabricated from Two Different Particle Sizes

Development of bio-inspired highly porous (\u3e50 vol.%) cellular ceramics is crucial to meet the demand of high-performance lightweight and damage-tolerant materials for a number of cutting-edge applications including impact energy absorption, biomedical implants, and energy storage. A key design feature that is observed in many natural materials (e.g., nacre, bamboo, wood, etc.) is the presence of hierarchical microstructure that results in an excellent synergy of various material properties, which are otherwise considered as mutually exclusive in current paradigm of materials design. To this end, development of multilayered, interconnected and anisotropic cellular ceramics could benefit the aforementioned applications. However, mimicking natural design principles to develop robust cellular materials is of paramount challenge because most of the available processing techniques are limited to the fabrication of simple materials microstructures. In contrast, freeze casting is one emerging technique that has shown great promise to develop nature-inspired hierarchical cellular ceramics. While a large number of recent studies focused on the development of process-structure correlations of freeze-cast ceramics, understanding of the structure-property relationships has been extremely limited. Therefore, this thesis develops a custom-made unidirectional freeze casting device to investigate the effects of the variation of the particle size (0.3 μm vs. 0.9 μm) on the microstructure and uniaxial compressive response of ice-templated sintered alumina scaffolds as a function of solids loading and freezing front velocity (FFV). For comparable solids loading and FFV, particle size effects on the microstructure of the scaffolds are observed to be significant. Moreover, transition of the pore morphology with the increasing solids loading and FFV is observed to be more drastic for the scaffolds processed from the 0.9 μm particles compared to the 0.3 μm particles. Similarly, particle size variations also significantly influenced the relative density and porosity of the scaffolds. However, in spite of the observed differences of the microstructure, relative density and porosity, uniaxial compressive stress-strain measurements revealed marginal particle size effects on the compressive strength. The apparent marginal particle size effects on the compressive strength are rationalized based on the relative variation of the relative density, pore aspect ratio, and interlamellae bridge density in between the sintered alumina scaffolds processed from 0.3 μm and 0.9 μm particle sizes. This study also suggests that particle size variation within a range of submicrometer to few micrometers (typical particle size range used in ceramic processing) can be uniquely employed to systematically modify the microstructure of the ice-templated sintered ceramic scaffolds, without significantly altering their uniaxial compressive response; which can be useful to optimize the structure-property relationships of the ice-templated scaffolds for the structural, biomedical and functional applications

Efficacy of Multifunctionalized Saccharide Constructs for the Attenuation of Amyloid-beta Toxicity

There is evidence that amyloid-beta (Aβ) toxicity is mediated through interactions and binding with neuronal surface sialic acids in Alzheimer’s disease (AD). The binding affinity is higher if the sialic acids are clustered and toxicity of Aβ was attenuated by removal of neuronal sialic acids. Thus, interfering with cell membrane-Aβ binding using biomimetics that could reproduce the clustered sialic acid structure could present us with a potential target for therapeutic intervention in AD. Based on this hypothesis, we developed several multifunctionalized sialic acid labeled chitosan compounds of different valency, or number of sialic acid per chitosan molecule, to attenuate Aβ toxicity. A cross-linker, 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) was used, which provided control over the degree of labeling of chitosan. After characterization, the ability of the complexes to attenuate toxicity of Aβ(1-40) was investigated in vitro. We found that all linear polysialylated complexes showed significant ability to attenuate Aβ toxicity, with optimum balance between intrinsic toxicity and protection around 37% labeling of chitosan. Moreover, unlabeled chitosan also showed some level of protective properties to the labeled compounds. Then, four biological sugars that are structural analogs of sialic acid (N-Acetylneuraminic acid) were used to decorate approximately 35% of the chitosan backbone using EDC chemistry. After characterization, the ability of these sugar complexes to attenuate toxicity of Aβ was investigated in vitro. We investigated whether sugars other than sialic acid provided better toxicity attenuation and attempted to understand the impact of sub-structures or unique –R groups of sialic acid and its analogs in Aβ toxicity attenuation. Our results show that oxygen substitution in the ring structure contributes to the intrinsic toxicity but also plays a role in Aβ toxicity attenuation. Similarly, the multi –OH tail present in sialic acid plays an important role in Aβ toxicity attenuation. This approach of designing effective biomimetics and of determining the structure-activity relationship has relevance with respect to the development of new intelligent class of therapeutic agents for AD. Although this work focuses on AD, this approach can be extended to other diseases involving misfolded proteins

Sialic Acid Conjugated Chitosan for the Attenuation of Amyloid-beta Toxicity

Amyloid-beta (Aβ), a 39 to 43 amino acid long peptide, is the primary species identified in senile plaques associated with Alzheimer’s disease (AD) and has been implicated in the neurotoxicity associated with AD. It is believed that Aβ toxicity is mediated through the interaction with neuronal membranes. A variety of evidence indicates that 1) Aβ may bind to the cell surface sialic acids, 2) the affinity of this interaction is higher if the gangliosides or sialic acids on the cell surface are clustered, 3) the removal of the surface sialic acids attenuate Aβ toxicity. Based on this data, we hypothesized that a biomimetic compound could be synthesized which would reproduce the clustered sialic acid structure of the cell surface, having antibody-like affinity towards Aβ, thus competing with the cell surface for Aβ binding. Our technique relies on attacking the theoretical “bottleneck” region in the Alzheimer’s process, i.e. the interaction of Aβ with neurons. This area can be considered as a bottleneck as there are several mechanisms that can transform the Aβ peptide into its toxic form. Also, the exact toxic form of Aβ peptide that attacks neurons is not agreed upon. However, it is agreed that preventing neuronal interaction prevents toxicity making the Aβ-cell interaction the “bottleneck” region. To explore this hypothesis further, we developed different sialic acid labeled compounds of different valency or number of sialic acids per molecule to attenuate Aβ toxicity. For this purpose, chitosan was used as a carrier molecule for sialic acids. EDC along with Sulfo-NHS was used as a cross-linker to couple the sialic acids with chitosan, with control over the degree of labeling. After verifying the presence of sialic acids on chitosan, the ability of this sialic acid-chitosan complex to attenuate the toxicity of aggregated Aβ was investigated in-vitro. Preliminary results indicate that the complex synthesized is biocompatible. Also, the results suggested that the compound has Aβ toxicity attenuating properties. Further studies will help elucidate the role of cell-surface sialic acids in Aβ toxicity. Drugs available today are merely symptoms alleviating and thus, these results can have implications in the design of intelligent compounds that can bind pathogenic Aβ for the treatment of Alzheimer’s disease

Control Flow Graph Based Multiclass Malware Detection Using Bi-normal Separation

Control flow graphs (CFG) and OpCodes extracted from disassembled executable files are widely used for malware detection. Most of the research in static analysis is focused on binary class malware detection which only classifies an executable as benign or malware. To overcome this issue, CFG based multiclass malware detection system that automatically classifies the malware into their respective families is proposed. The use Bi-normal separation (BNS) as a feature scoring metric. Experimental results show that proposed method using BNS outperforms compared to hitherto use technique of document Frequency for multiclass metamorphic malware detection and achieves detection accuracy of 99.5 per cent.

Multiple Intelligences and Drama Techniques: A study in Rural ESL classroom

Drama is useful for language learning. It shifts the classroom from teacher centric to learner centric.  Language learning can benefit from the use of drama as it moves the focus of the classroom from the teacher to the learner.  The objective of this study is to examine how drama techniques can be effective in developing linguistic skills in ESL classrooms, particularly for rural students. This study is aimed to determine whether the use of drama techniques can improve both linguistic intelligence and interpersonal intelligence among undergraduate ESL students. The study was conducted in a rural undergraduate Government college from the perspective of teachers and students. The study revealed that Linguistic intelligences and interpersonal intelligences improved through the use of drama techniques, such as readers theatre, skit, and role-play. ‘The Merchant of Venice’ was the textbook for the BCom III sem students. And drama techniques were used to teach the play in the ESL classroom. There were total 40 participants in the study. A mixed-methods approach was used in this study, involving both quantitative and qualitative methods such as document analysis, semi-structured interviews, feedback, and questionnaires. Findings from this study suggest that the use of drama techniques led to improvements in both linguistic intelligence and interpersonal intelligence among undergraduate ESL students. The study also revealed that the use of drama techniques was well received by both the teachers and the student

Microscale experiments in chemistry - the need of the new millenium 2. Experiments which bring theory closer to laboratories

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