Development of Vapor Deposited Silica Sol-Gel Particles for a Bioactive Materials System to Direct Osteoblast Behavior

Tissue engineering and regenerative medicine have emerged in an effort to generate replacement tissues capable of restoring native tissue structure and function, but because of the complexity of biologic system, this has proven to be much harder than originally anticipated. Silica based bioactive glasses are popular as biomaterials because of their ability to enhance osteogenesis and angiogenesis. Sol-gel processing methods are popular in generating these materials because it offers: 1) mild processing conditions; 2) easily controlled structure and composition; 3) the ability to incorporate biological molecules; and 4) inherent biocompatibility. The goal of this work was to develop a bioactive vaporization system for the deposition of silica sol-gel particles as a means to modify the material properties of a substrate at the nano- and micro- level to better mimic the instructive conditions of native bone tissue, promoting appropriate osteoblast attachment, proliferation, and differentiation as a means for supporting bone tissue regeneration. The size distribution, morphology and degradation behavior of the vapor deposited sol-gel particles developed here were found to be dependent upon formulation (H2O:TMOS, pH, Ca/P incorporation) and manufacturing (substrate surface character, deposition time). Additionally, deposition of these particles onto substrates can be used to modify overall substrate properties including hydrophobicity, roughness, and topography. Deposition of Ca/P sol particles induced apatite-like mineral formation on both two- and three-dimensional materials when exposed to body fluids. Gene expression analysis suggests that Ca/P sol particles induce upregulation osteoblast gene expression (Runx2, OPN, OCN) in preosteoblasts during early culture time points. Upon further modification-specifically increasing particle stability-these Ca/P sol particles possess the potential to serve as a simple and unique means to modify biomaterial surface properties as a means to direct osteoblast differentiation

Implications of sustainable agricultural intensification for family farming in Africa: anthropological perspectives

In this paper, we will explore the ways in which sustainable intensification interventions often overlook fundamental social dynamics in rural landscapes. We provide evidence of the underlying social, political and environmental contexts that affect farmers’ land-use decisions. While there are numerous initiatives to promote a Green Revolution for Africa, many tend to be dominated by technical fixes that fail to understand rural farmers’ condi - tions or aspirations and focus narrowly on increasing productivity. These technical solu - tions rarely address the broader social, economic and political challenges to agricultural production and farmers’ livelihoods. Finally, top-down technical approaches frequently fail to build on the local knowledge, innovative capacity and expertise of farmers and members of rural communities throughout Africa. Examples from fieldwork in Ghana, Ethiopia and Tanzania are used to illustrate our arguments

Evaluating Land Management Options (ELMO): a participatory tool for assessing farmers’ sustainable land management decision preferences and trade-offs

This document provides guidance on applying the ELMO tool. It is primarily targeted at researchers seeking to collect information about the social and economic drivers of land use decisions, and wishing to investigate farmers’ sustainable land management preferences and trade-offs. As illustrated on the facing page, ELMO is organised around three basic questions, and entails 10 steps. Although these steps follow a logical, iterative process, it should be emphasised that the tool can be modified and adapted to the specific needs and context within which it is being applied. It is not always necessary to apply each and every step

A Guide for participatory mapping of ecosystem services in multiuse agricultural landscapes: How to conduct a rapid spatial assessment of ecosystem services

This guide presents a step-by-step approach in using a participatory mapping method with community members to rapidly identify and map ecosystem services and changes in their supply across multiuse agricultural landscapes. Nongovernmental organizations (NGOs), government agencies and researchers can use this approach to learn from communities about how they use and access natural resources. This activity uses a landscape approach to help land management practitioners understand the ways in which people depend on and access ecosystem services and how changes in their availability impact livelihoods across the landscape. The mapping exercise involves using free, high resolution satellite imagery from Google Earth Pro, which presents an aerial view of the community in fine detail. Participants from the community in question identify key features on the map, which help them to understand the extent of the area the map represents. They are then led through a discussion on their resources such as water, livestock, cultivated land and uncultivated land. Through the discussion participants identify: (1) where resources are located on the landscape and how they are used; (2) changes in the supply of resources and how these changes are impacting livelihoods; and (3) restrictions to access, conflicts over use and management of each resource in question. Mapping with different groups, such as men, women and youth can show which resources are most important to different groups as well as differences in access and perceptions of change. The mapping exercise is intended to take between two and a half and three hours: including introductory and concluding discussions can add on another two hours. This guide presents examples and tips from mapping exercises that tested this approach in Ghana, Kenya, Malawi and Tanzania. We outline how this mapping exercise could be used in research, development and planning. Additionally, this guide includes appendices that contain: (1) a detailed explanation of how to create maps for each activity; (2) a set of materials that have been developed to accompany the mapping exercise; (3) steps for digitizing the maps (4) case study examples; and (5) additional sources of information

Resolving the titer of murine cytomegalovirus by plaque assay using the M2-10B4 cell line and a low viscosity overlay.

BACKGROUND: Murine cytomegalovirus (MCMV) is increasingly used as an infectious model to investigate host-pathogen interactions in mice. Detailed methods have been published for using primary murine embryonic fibroblasts (MEFs) for preparing stocks and determining viral titers of MCMV. For determining the titer of MCMV by plaque assay, these methods rely on a high viscosity media that restricts viral spreading through the supernatant of the culture, but is also usually too viscous to pipet. Moreover, MEFs must be repeatedly generated and can vary widely from batch-to-batch in purity, proliferation rates, and the development of senescence. In contrast, the M2-10B4 bone marrow stromal cell line (ATCC # CRL-1972), which is also permissive for MCMV, has been reported to produce high-titer stocks of MCMV and has the considerable advantages of growing rapidly and consistently. However, detailed methods using these cells have not been published. METHODS: We modified existing protocols to use M2-10B4 cells for measuring MCMV titers by plaque assay. RESULTS: We found that MCMV plaques could be easily resolved on monolayers of M2-10B4 cells. Moreover, plaques formed normally even when cultures of M2-10B4 cells were less than 50% confluent on the day of infection, as long as we also used a reduced viscosity overlay. CONCLUSIONS: Overall, our protocol enabled us to use a consistent cell line to assess viral titers, rather than repeatedly producing primary MEFs. It also allowed us to start the assay with 4-fold fewer cells than would be required to generate a confluent monolayer, reducing the lead-time prior to the start of the assay. Finally, the reduced viscosity CMC could be handled by pipet and did not need to be pre-mixed with media, thus increasing its shelf-life and ease-of-use. We describe our results here, along with detailed protocols for the use of the M2-10B4 cell lines to determine the titer and grow stocks of MCMV

V4: Sub-basin management and governance of rainwater and small reservoirs

A strong international consensus has been created regarding the need for Integrated Water Resources Management (IWRM) and what it means. The river basin is then invariably singled out as the natural unit for organizing water management. Two main reasons for these shortcomings are generally presented: a lack of political will and socio-political externalities. Calls for more reforms follow but they rarely question policy models themselves. As a consequence, they face the same shortcomings they were meant to address. This project aims at understanding the processes that govern IWRM policy-making, practices and research in the Volta Basin (Ghana and Burkina Faso)

Improved Peddler for the Ann Arbor Veterans Affairs Healthcare System

ME450 Capstone Design and Manufacturing Experience: Fall 2015The Ann Arbor Veterans Association (AAVA) has a Home Based Cardiovascular Rehabilitation (HBCR) program for patients who have experienced a significant cardiac event and live in areas far from the AAVA. A peddler sent home with veterans for this program has been identified as displeasing and uncomfortable to use; we have been tasked in redesigning the machine to fit the needs of healthcare professionals and alleviate the complaints expressed by users. The areas we have determined that need redesign are: application of pedaling resistance, pedal design, a time and distance display, and anchoring of the peddler during use - all while maintaining the ability to pedal with hands or feet and a relatively compact and lightweight peddler that will be portable for veterans of all ages. The concepts we have chosen to meet these needs are a band brake to apply resistance to a rotor, larger pedals, a bike computer, and increased coefficient of friction between the peddler and the surface. Our final design incorporates these chosen concepts into a complete peddler which meets the key specifications.http://deepblue.lib.umich.edu/bitstream/2027.42/117342/1/ME450-F15-Project25-FinalReport.pd

Eye movements, visual search and scene memory in an immersive virtual environment

textVisual memory has been demonstrated to play a role in both visual search and attentional prioritization in natural scenes. However, it has been studied predominantly in experimental paradigms using multiple two-dimensional images. Natural experience, however, entails prolonged immersion in a limited number of three-dimensional environments. The goal of the present experiment was to recreate circumstances comparable to natural visual experience in order to evaluate the role of scene memory in guiding eye movements in a natural environment. Subjects performed a continuous visual-search task within an immersive virtual-reality environment over three days. We found that, similar to two-dimensional contexts, viewers rapidly learn the location of objects in the environment over time, and use spatial memory to guide search. Incidental fixations did not provide obvious benefit to subsequent search, suggesting that semantic contextual cues may often be just as efficient, or that many incidentally fixated items are not held in memory in the absence of a specific task. On the third day of the experience in the environment, previous search items changed in color. These items were fixated upon with increased probability relative to control objects, suggesting that memory-guided prioritization (or Surprise) may be a robust mechanisms for attracting gaze to novel features of natural environments, in addition to task factors and simple spatial saliency.Psycholog