Cytoskeletal Configuration Modulates Mechanically Induced Changes in Mesenchymal Stem Cell Osteogenesis, Morphology, and Stiffness

Mesenchymal stem cells (MSC) responding to mechanical cues generated by physical activity is critical for skeletal development and remodeling. Here, we utilized low intensity vibrations (LIV) as a physiologically relevant mechanical signal and hypothesized that the confined cytoskeletal configuration imposed by 2D culture will enable human bone marrow MSCs (hBMSC) to respond more robustly when LIV is applied in-plane (horizontal-LIV) rather than out-of-plane (vertical-LIV). All LIV signals enhanced hBMSC proliferation, osteogenic differentiation, and upregulated genes associated with cytoskeletal structure. The cellular response was more pronounced at higher frequencies (100 Hz vs 30 Hz) and when applied in the horizontal plane. Horizontal but not vertical LIV realigned the cell cytoskeleton, culminating in increased cell stiffness. Our results show that applying very small oscillatory motions within the primary cell attachment plane, rather than perpendicular to it, amplifies the cell’s response to LIV, ostensibly facilitating a more effective transfer of intracellular forces. Transcriptional and structural changes in particular with horizontal LIV, together with the strong frequency dependency of the signal, emphasize the importance of intracellular cytoskeletal configuration in sensing and responding to high-frequency mechanical signals at low intensities

"Imagining a just and equitable African Christian community" : a critical analysis of the contribution of Theological Education Fund/Ecumenical Theological Education (1910-2012).

Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2013.This study utilizes a systematic review method to assess literature about the Protestant Christian tradition to enhance theological education in the African context. It explores the development and transformation of African theological education in the period 1910 to 2012. A ‘follow the money trail method of investigation’ was utilized to expose the theological issues that African theologians fundraised for African theological education through the Theological Education Fund/Ecumenical Theological Education of World Council of Churches. These were perceived as crucial in developing an African theological education that promotes the principles of a just and equitable African Christian community. The primary data was extracted by utilizing an approach that demanded searching various media sources which included electronic databases. The search strategy for electronic databases was developed from the key words and phrases of the research question. The search yielded about 10, 821 results and having carefully perused through them, 169 primary sources were included in this study. This was significant as it helped make sense of a large body of literature and was a means of isolating and synthesising the main theories and pragmatics of African theological education. The insights gained from this study are significant as a contribution to the current search for a vision of African theological education that promotes the principles of a just and equitable African Christian community in the twenty-first century. The study makes two unique contributions in the search and vision for African theological education. The contribution lies in constructing an example of an African pedagogy of community of life which is based on education for life-giving. This pedagogy is based on the Bemba understanding of insaka which is a process of life-giving-learning methodology. This theme is as relevant for global Christianity as it is to the Bemba people in their quest for life-giving theological education. Another critical contribution lies in the understanding that through Africanization, African theological education has been in a process of acquiring its own unique character or theological identity. African theological education has shifted from a merely dogmatic orientation to praxis orientation. This is based on a theological pedagogy that recognises that doing theological education involves critical engagement in a missional process of liberation—of seeking fullness of life in its interpenetrative dimensions as spiritual-material starting with the least of the community, but embracing the whole of God’s creation. To achieve this, theological education has to cut across denominational allegiances, privileging of academic disciplines, and embracing the insaka pedagogy of life through ecumenical and trans-disciplinary approaches. The viability of African theological education resides in its critical engagement with the concrete societal challenges of the African peoples. As a result, this study argues that creating a just and equitable African Christian community to a large extent depends on embracing the life-giving pedagogy as an imperative in African theological education

Genetic and tissue level muscle-bone interactions during unloading and reambulation

Little is known about interactions between muscle and bone during the removal and application of mechanical signals. Here, we applied 3wk of hindlimb unloading followed by 3wk of reambulation to a genetically heterogeneous population of 352 adult mice and tested the hypothesis that changes in muscle are associated with changes in bone at the level of the tissue and the genome. During unloading and relative to normally ambulating control mice, most mice lost muscle and cortical bone with large variability across the population. During reambulation, individual mice regained bone and muscle at different rates. Across mice, changes in muscle and trabecular/cortical bone were not correlated to each other during unloading or reambulation. For unloading, we found one significant quantitative trait locus (QTL) for muscle area and five QTLs for cortical bone without overlap between mechano-sensitive muscle and cortical bone QTLs (but some overlap between muscle and trabecular QTLs). The low correlations between morphological changes in muscle and bone, together with the largely distinct genetic regulation of the response indicate that the premise of a muscle-bone unit that co-adjusts its size during (un)loading may need to be reassessed. © 2016, International Society of Musculoskeletal and Neuronal Interactions. All rights reserved.NASA (NAG 9-1499 -- NNX-12AL25G

Modellierung der Landnutzungsdynamik in Zentralbenin mit dem XULU-Framework

Starkes Bevölkerungswachstum und zunehmende Ressourcendegradierung sind immense Herausforderungen für die weitere Zukunft Afrikas. Dabei spielen Landnutzungs- und Landbedeckungsveränderungen eine zentrale Rolle, da hierdurch Ökosystemfunktionen beeinträchtigt und die Existenzgrundlage der ländlichen Bevölkerung gefährdet werden können. Die vorliegende Arbeit untersucht mit einem Methodenverbund aus Fernerkundung, GIS und Modellierung die vorherrschende Landnutzungsdynamik sowie Szenarien zukünftiger Landnutzungsveränderungen in Zentralbenin. Die Arbeit entstand im Rahmen des IMPETUS-Projekts, das die Auswirkungen des globalen Wandels auf den Wasserkreislauf in Westafrika untersucht. Diese Untersuchungsregion ist durch eine geringe Bevölkerungsdichte und kleinbäuerliche Produktionssysteme gekennzeichnet. Die Analyse von Satellitenbildern der Jahre 1991 und 2000 zeigt eine regional differenzierte Landnutzungsdynamik. So besteht schon heute in Regionen mit größerer Bevölkerungsdichte eine deutliche Flächenknappheit. Zusätzliche landwirtschaftliche Flächen können dort nur auf Kosten der Brachezeit gewonnen werden, was langfristig zu einer Abnahme der Bodenfruchtbarkeit führt. Weite Teile des Untersuchungsgebietes weisen jedoch noch großflächige Wald- und Savannengebiete auf, die zunehmend zum Zielgebiet landsuchender Migranten werden. Rechtsunsicherheiten bezüglich der Bodennutzung und ein nicht vorhandenes Ressourcenmamangement führen hier zu einer ungelenkten Agrarkolonisation mit entsprechend hohen Entwaldungsraten. Im untersuchten Zeitraum wurden ca. 61000 ha Savanne und Wald in Ackerland umgewandelt, wobei regionale "Hot-Spots" der Entwaldung durch die Satellitenbildanalyse aufgedeckt werden konnten. Insgesamt nahm die landwirtschaftlich genutzte Fläche um 70 % zu. Eine besondere Schwierigkeit für die Landnutzungsklassifikation stellte die starke intra-annuelle Vegetationsdynamik durch Regen- und Trockenzeit dar, was zu unpräzisen Flächenangaben der Landnutzungsklassifikation führen kann. Um unterschiedliche Szenarien der zukünftigen Landnutzung/Landbedeckung berechnen zu können, wurde das CLUE-S-Modellkonzept für den Untersuchungsraum regionalisiert. Durch die Integration des Modellkonzeptes in die neu entwickelte Modellierungsplattform XULU wurde eine deutliche Verbesserung der Benutzbarkeit durch ein integriertes Datenmanagement und eine flexible Modellkontrolle erreicht. Ein wesentlicher Input-Parameter des Modells sind Wahrscheinlichkeitskarten der Landnutzung, die mittels logistischer Regressionsmodelle erstellt wurden. Mit insgesamt elf -- räumlich expliziten -- erklärenden Variablen ("driving forces") können so die Muster der Landnutzung und der Landnutzungsveränderung mit hoher Genauigkeit erklärt werden. Sozio-ökonomische Faktoren wie Bevölkerungsdichte und Distanzfunktionen (z.B. Abstand zur nächsten Straße), besitzen den größten Einfluss sowohl auf die Landnutzungsverteilung als auch auf die Landnutzungsänderung. Überregionale Faktoren wie der Abstand zum nächsten größeren Marktort haben dagegen nur einen geringen Einfluss auf die Landnutzungsänderung. Dies bestätigt die These, wonach die Bevölkerungsdynamik der primäre Antriebsfaktor der Entwicklung im Untersuchungsraum ist und nicht marktökonomische Proxyfaktoren. Naturräumliche Faktoren haben nur dann einen Einfluss auf die Landnutzung, wenn es sich um Sonderstandorte handelt (Talbereiche, Inselberge). Die Szenarienberechnungen basieren daher in erster Linie auf den Ergebnissen demographischer Projektionen sowie auf dem Bedarf an landwirtschaftlicher Fläche pro Kopf. Je nach institutionellen und ökonomischen Rahmenbedingungen variiert der landwirtschaftliche Flächenzuwachs um ca. 20 %. Die Waldressourcen sind besonders im ökonomisch pessimistischen Szenario gefährdet, auch unter Schutz stehende Staatswälder werden dann zum Teil in Ackerflächen umgewandelt. Eine Intensivierung der Anbausysteme, eine nachhaltige Landnutzungsplanung und ein institutionell gesicherter Waldschutz zeigen dagegen ein erhebliches Potential zur Reduktion der Entwaldung in Zentralbenin.Modelling the land use dynamics in Central Benin with the XULU-framework High population growth and ongoing degradation of natural resources are immense challenges for the near future of Africa. Changes in land use and land cover play thereby a major role, as the ecosystem functioning is affected and the livelihood security of the rural population might be endangered. This work examines the present and possible future changes in land use and land cover with a combination of GIS, remote sensing and modelling methods in Central Benin. The study was carried out under the framework of the IMPETUS-Project, which investigates the effetcs of global change on the water cycle in West Africa. The study area is characterised by a low population density and smallholder farming systems. The analysis of satellite images from 1991 and 2000 reveal regionally different land use dynamics. A pronounced shortage of land exists in regions with higher population density. There, the expansion of agricultural area is only possible at the expense of fallow time, which will decrease the soil fertility in the long term. However, large parts of the study area are covered by forests and savannas, which became a target area of migrating farmers. Insecure land rights and an inexistent resource management are leading towards an agricultural colonisation with high deforestation rates. During the analysed time period, approx. 61000 ha of savannas and forests were converted into agriculturally used area, whereas regional hot-spots of deforestation could be revealed by satellite image analysis. Overall, the agriculturally used areas have increased by 70 %. A special challenge during land cover classification arises due to the high intra-annual vegetation dynamics, which are caused by alternating rain and dry seasons. This can lead to imprecise area measurements of the classification. To calculate different scenarios of future land use and land cover changes, the CLUE-S model approach was regionalised for the study area. The model approach was embedded in a newly developed Extendable Unified Land Use modelling platform (XULU), which improved the usability through an integrated data management and flexible model control during runtime. An important input for the model are probability maps of every land use type, which were created by means of logistic regression. The pattern of land use and land use changes were explained with a high accuracy by eleven spatial explicit driving forces. Socioeconomic factors like population density or distance functions (e.g. distance to next road) had the highest predicting power for the patterns of land use and land use changes as well. Supra-regional operating factors like distance to important market places did not contribute much to the explanation. This affirmed the thesis, that rather population dynamics than proxy factors of market economy drive the evolution in the study area. Factors concerning the natural environment only influence the explanation significantly, if they describe specific locations (valley areas, Inselbergs). The calculations of scenarios were therefore based on the results of demographic projections and the demand for agricultural area per capita. The increase of the agricultural area differs up to 20 % according to the institutional and economic basic conditions. Especially the economic pessimistic scenario shows a high threat on the forest resources in the study area. Even protected forests are subject to a high probability of conversion into agricultural land. In contrast, an intensification of the production systems, a sustainable resource planning and an institutionally secured forest management demonstrate a high potential to reduce the deforestation in Central Benin

Propuesta de mejoramiento a través de la implementación del modelo integrado de planeación y gestión en el área de tesorería de la alcaldía municipal de Tenerife.

Este proyecto presente, busca generar una propuesta clara, fundamentada y al alcance de la empresa, que le permita lograr una mejor planeación de sus procesos, específicamente en el área de tesorería, con el fin de garantizar calidad en la realización de las funciones y así contribuir en la eficacia de la gestión pública de la entidad; a partir de la implementación de unos procedimientos particulares a través de guías de acción encaminadas a sugerir formas de administración de la información, documentación, planes de control y monitoreo de los mismos, dirigidos a la estandarización y formalización del proceso, y que en todo caso vinculan a todos y 3 cada uno de los agentes al interior de la organización publica y que genera la necesidad de tener en cuenta , adicionalmente, a aquellos que de manera eventual o transitoria tienen alguna vinculación con la entidad. En este proceso se concibe el sistema de gestión de calidad como soporte fundamental de apoyo a las actividades de formación y tendencia a implementar modelos de calidad en la gestión de entidades públicas, la adopción de acciones de dirección y participación que apropian herramientas y ejecutan acciones institucionales encaminadas a desarrollar una cultura de calidad, inmersa en la filosofía de mejoramiento continuo o en procesos de modernización institucional que implican actividades de seguimiento y medición, documentación de procesos y búsqueda constante de sectores críticos que aporten a una mejor definición de la misión y objetivos. Esta propuesta, se sitúa hacia la herramienta esencial administrativa orientada hacia el mejoramiento y actualización del sistema de gestión de Calidad enfocada los procesos y procedimientos de la Alcaldía Municipal de Tenerife, el cual se identificó falencias de la organización en cuanto a documentación, estandarización, entrega de informes, planeación de actividades diarias, procedimientos que se deben realizar en este ente territorial y que se incumplen, por falta en un enfoque, ruta, cronograma, en general por la ausencia de planificación, dirección, y organización

Low-Level Vibrations Retain Bone Marrow's Osteogenic Potential and Augment Recovery of Trabecular Bone during Reambulation

Mechanical disuse will bias bone marrow stromal cells towards adipogenesis, ultimately compromising the regenerative capacity of the stem cell pool and impeding the rapid and full recovery of bone morphology. Here, it was tested whether brief daily exposure to high-frequency, low-magnitude vibrations can preserve the marrow environment during disuse and enhance the initiation of tissue recovery upon reambulation. Male C57BL/6J mice were subjected to hindlimb unloading (HU, n = 24), HU interrupted by weight-bearing for 15 min/d (HU+SHAM, n = 24), HU interrupted by low-level whole body vibrations (0.2 g, 90 Hz) for 15 min/d (HU+VIB, n = 24), or served as age-matched controls (AC, n = 24). Following 3 w of disuse, half of the mice in each group were released for 3 w of reambulation (RA), while the others were sacrificed. RA+VIB mice continued to receive vibrations for 15 min/d while RA+SHAM continued to receive sham loading. After disuse, HU+VIB mice had a 30% greater osteogenic marrow stromal cell population, 30% smaller osteoclast surface, 76% greater osteoblast surface but similar trabecular bone volume fraction compared to HU. After 3 w of reambulation, trabecular bone of RA+VIB mice had a 30% greater bone volume fraction, 51% greater marrow osteoprogenitor population, 83% greater osteoblast surfaces, 59% greater bone formation rates, and a 235% greater ratio of bone lining osteoblasts to marrow adipocytes than RA mice. A subsequent experiment indicated that receiving the mechanical intervention only during disuse, rather than only during reambulation, was more effective in altering trabecular morphology. These data indicate that the osteogenic potential of bone marrow cells is retained by low-magnitude vibrations during disuse, an attribute which may have contributed to an enhanced recovery of bone morphology during reambulation

Creation as a dwelling place of God : a critical analysis of an African biocentric theology in the works of Gabriel M. Setiloane.

Thesis (M.Th.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.The study argues that for the African church to become responsive to the changing circumstances with regard to the African ecological crisis, there is a need to reconstruct those aspects of Christianity that are non-functional in an African Christian context. Drawing insights from both Gabriel Setiloane‘s thoughts on African Biocentric theology and the myths of origin among the Yoruba, the Chewa and the Boshongo people, the study argues that in African cosmology, there is a clear interconnectedness that does not allow for complete independence of one another as is the case in the western world-view. In this regard, the study argues that these African myths of origin are not only feasible but are a more plausible theological response to the contemporary understanding of the universe emerging from scientific explanation of the development of life on earth than the Judaeo-Christian myth of origin (Setiloane 1986:15). In African thought, as envisaged by Setiloane and the three myths of origin, cosmic harmony and balance depend on the integrity of each being for the sake of all other creation. This means that every action that does not affirm life in the cosmos has an effect not only on other creation but on humanity as well. Thus, the study proposes that for African Christian ecological theology to be effective in the context of Africa, first, it must embrace a unified approach to the cosmos and all things because both the physical and spiritual share the same community and the Creator. Thus, there will be equality between humans and nonhuman nature. Second, it must rediscover the Holy Spirit in the African concept of Vital Force and God must be seen as dwelling in the cosmos through the Holy Spirit. This view will re-sacralise the material universe on account that it will be seen as the holy of holies, a dwelling place of God

Ex vivo determination of bone tissue strains for an in vivo mouse tibial loading model

AbstractPrevious studies introduced the digital image correlation (DIC) as a viable technique for measuring bone strain during loading. In this study, we investigated the sensitivity of a DIC system in determining surface strains in a mouse tibia while loaded in compression through the knee joint. Specifically, we examined the effect of speckle distribution, facet size and overlap, initial vertical alignment of the bone into the loading cups, rotation with respect to cameras, and ex vivo loading configurations on the strain contour maps measured with a DIC system.We loaded tibiae of C57BL/6 mice (12 and 18 weeks old male) up to 12N at 8N/min. Images of speckles on the bone surface were recorded at 1N intervals and DIC was used to compute strains. Results showed that speckles must have the correct size and density with respect to the facet size of choice for the strain distribution to be computed and reproducible. Initial alignment of the bone within the loading cups does not influence the strain distribution measured during peak loading, but bones must be placed in front of the camera with the same orientation in order for strains to be comparable. Finally, the ex vivo loading configurations with the tibia attached to the entire mouse, or to the femur and foot, or only to the foot, showed different strain contour maps.This work provides a better understanding of parameters affecting full field strain measurements from DIC in ex vivo murine tibial loading tests

Low-Intensity Vibration Protects the Weight-Bearing Skeleton and Suppresses Fracture Incidence in Boys With Duchenne Muscular Dystrophy: A Prospective, Randomized, Double-Blind, Placebo-Controlled Clinical Trial

The ability of low-intensity vibration (LIV) to combat skeletal decline in Duchenne Muscular Dystrophy (DMD) was evaluated in a randomized controlled trial. Twenty DMD boys were enrolled, all ambulant and treated with glucocorticoids (mean age 7.6, height-adjusted Z-scores [HAZ] of hip bone mineral density [BMD] −2.3). Ten DMD boys were assigned to stand for 10 min/d on an active LIV platform (0.4 g at 30 Hz), while 10 stood on a placebo device. Baseline and 14-month bone mineral content (BMC) and BMD of spine, hip, and total body were measured with DXA, and trabecular bone density (TBD) of tibia with quantitative computed tomography (QCT). All children tolerated the LIV intervention well, with daily compliance averaging 78%. At 14 months, TBD in the proximal and distal tibia remained unchanged in placebo subjects (−1.0% and −0.2%), while rising 3.5% and 4.6% in LIV subjects. HAZ for hip BMD and BMC in the placebo group declined 22% and 13%, respectively, contrasting with no change from baseline (0.9% and 1.4%) in the LIV group. Fat mass in the leg increased 32% in the placebo group, contrasting with 21% in LIV subjects. Across the 14-month study, there were four incident fractures in three placebo patients (30%), with no new fractures identified in LIV subjects. Despite these encouraging results, a major limitation of the study is—despite randomized enrollment—that there was a significant difference in age between the two cohorts, with the LIV group being 2.8y older, and thus at greater severity of disease. In sum, these data suggest that noninvasive LIV can help protect the skeleton of DMD children against the disease progression, the consequences of diminished load bearing, and the complications of chronic steroid use. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research