Microengineering Aligned Collagen Substrates In Microfluidic Systems

Cells in vivo are surrounded by a fibrous matrix of proteins and macromolecules called the extracellular matrix (ECM), of which type I collagen is the major constituent. During tissue development or cell-matrix interactions, collagen fibers organize into aligned domains with defined degrees of alignment and directionality. Aligned fibers guide stem cell differentiation and influence cell-cell communication and cell motility. In the tumor microenvironment, aligned fibers guide tumor cell invasion and have been linked to poor patient outcomes. Since fiber alignment instructs cell behavior in vivo, there is a need for in vitro models to replicate fiber alignment and thus provide a relevant microenvironment for cells. Microfluidic systems have been established as advanced cell culture platforms to provide precise control over soluble factor concentration, cell patterning, and fluid flow. However, controlling the fiber alignment of a 3D material within them has remained a challenge. This work addresses existing technological challenges to integrate 3D collagen matrices with aligned fibers into microfluidic platforms. To do so, this work i) Demonstrates for the first time that extensional flows can align 3D collagen matrices (250 µm thick) in a microchannel, ii) Develops modular microfluidic platforms with capabilities to directly access and perfuse 3D collagen, and iii) Develops biofabrication capabilities to create interfaces between different ECM materials in 3D, and create tissue barriers using ultrathin nanomembranes. It is anticipated that the novel ECM microengineering capabilities and approach to integrating the engineered matrices into microfluidic devices will provide a path to develop tissue-specific in vitro models with engineered matrices

Efficient Template-Based Nanomanufacturing of Carbon Nanotube Arrays for Cell Applications

Carbon nanotube arrays have been found to be highly effective at carrying out intracellular delivery of cargo at high efficiencies while ensuring cell viability. Template based chemical vapor deposition is a commonly used process to fabricate these arrays. However, current etching methods used to expose carbon nanotubes from templates are expensive and time consuming. The high cost and time-consuming processes currently required to fabricate such arrays are factors which limit the commercialization of this technology and inhibit scope for larger research programs. In this thesis, alternative nanofabrication methods were explored with the aim of making the fabrication of CNT arrays cost effective and efficient. Mechanical polishing coupled with wet chemical etching is shown as a feasible alternative option to dry etching. The effects of process variables on physical properties of CNT arrays have been studied and quantified in order to demonstrate control over the process. Scanning Electron Microscopy has been used to qualitatively understand the differences between CNT arrays fabricated using dry etching and the alternative process. Cell culture has been demonstrated on the CNT arrays and the potential to use 3D printing to fabricate a nanofluidic device is also demonstrated. The alternative process can save etching time by 97% while maintaining a similar level of control over the process. This study, therefore, opens the path to quicker production of CNT arrays at low cost for biomedical use

Crowdsourcing Rural Data Collection

The rise of geospatial information on popular websites and its comparative lack in rural areas prompted the pilot project described here to apply crowdsourcing techniques to community mapping. The 3-month project yielded many valuable lessons to apply to future endeavors, but did not yield enough point-of-interest (POI) data to merit an analysis of its accuracy. Results were disappointing in that few POIs were collected, despite participants\u27 initial enthusiasm and hours of training. Key questions for the future are the following. Is it feasible to sustain volunteer-based community mapping efforts in rural areas? And, if so, what kind of incentives should be offered

Asbestos risk assessment in Pakistan: Current scenario and way forward

[No abstract available

THE RELATIONSHIP BETWEEN CORRUPTION AND ECONOMIC GROWTH IN PAKISTAN — LOOKING BEYOUND THE INCUMBENT

Corruption has opaque significant consideration for researchers during the last few decades due to its effect on economic growth. This study examines the relationship between corruption and economic growth in Pakistan, covering the period from 1985 to 2010. Stationarity of the variables was checked through unit root test and then apply multiple regression technique. The results shows that government expenditures, education expenditures and population growth has a positive impact on per capita GDP, however, domestic investment and corruption has a negative impact on per capita income in Pakistan. It implies that corruption is a major factor impeding economic development. Corruption hampers economic growth, disproportionately burdens the poor and undermines the effectiveness of investment and aid

Field Testing Volunteer Geographic Information Collection – The Viability of Community Mapping

1 electronic resource (PDF). This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu.The ubiquity of Internet service and the GPS chip, fused into a device that people cannot leave home without (their phone), has facilitated the rise of “Volunteered Geographic Information” (VGI). VGI has a promising premise; locals go where outsiders can’t and are theoretically able to provide highly accurate and useful spatial information. This paper explores one aspect of VGI with the findings from a study of an effort to train volunteers to map “Points of Interest” (POIs) in two Minnesota counties. The findings illustrate that volunteers in rural tourism hubs find the idea of collecting and representing their community’s POIs on interactive digital maps relatively easy and useful for community development and tourism. However, the volunteers’ apparent enthusiasm does not correlate with the amount of data they collected and mapped

Warehouse Location Decision in Pakistan:A Real Case Study

The manufacturing industry in Pakistan ispassing through a critical phase of its history. In the changing market placeconsumer are increasingly vigilant and demanding better quality, morecompetitive prices and shorter lead times. Maintaining cost effectivemanufacturing along with it distribution to the different customers across thecountry is becomes challenging day by day. In this paper, we propose anadditional new warehouse location in Pakistan using transportation cost as adecision factor. Initially the proposed warehouse will be run by the third partywarehouse service provider on temporary basis, so that it lower down theinventory level of Lahore warehouse from 0.4 million liters to 0.2 millionliters, saves approximately 1.5 Million Rs. / year with improved customerservice