Journal of African Christian Biography: v. 4, no. 1

A publication of the Dictionary of African Christian Biography with U.S. offices located at the Center for Global Christianity and Mission at Boston University. This issue focuses on: 1. Introducing African Christian Biography. 2. Modern African Church History and the Streetlight Effect. 3. Both African and Christian. 4. Musicians and Composers in African Christianity. 5. Yared. 6. John Knox Bokwe. 7. Recent Print and Digital Resources Related to Christianity in Africa. 8. Guidelines for Article Contributors. 9. Suggested Interview Guidelines and Questions. 10. Guidelines for Book Reviewers

Targeted inactivation of integrin-linked kinase in hair follicle stem cells reveals an important modulatory role in skin repair after injury

Integrin-linked kinase (ILK) is key for normal epidermal morphogenesis, but little is known about its role in hair follicle stem cells and epidermal regeneration. Hair follicle stem cells are important contributors to newly formed epidermis following injury. We inactivated the Ilk gene in the keratin 15 - expressing stem cell population of the mouse hair follicle bulge. Loss of ILK expression in these cells resulted in impaired cutaneous wound healing, with substantially decreased wound closure rates. ILK-deficient stem cells produced very few descendants that moved toward the epidermal surface and into the advancing epithelium that covers the wound. Furthermore, those few mutant cells that homed in the regenerated epidermis exhibited a reduced residence time. Paradoxically, ILK-deficient bulge stem cells responded to anagen growth signals and contributed to newly regenerated hair follicles during this phase of hair follicle growth. Thus ILK plays an important modulatory role in the normal contribution of hair follicle stem cell progeny to the regenerating epidermis following injury. © 2011 Nakrieko et al

Optical spin-transfer-torque-driven domain-wall motion in a ferromagnetic semiconductor

We demonstrate optical manipulation of the position of a domain wall in a dilute magnetic semiconductor,GaMnAsP. Two main contributions are identified. First, photocarrier spin exerts a spin-transfer torque on the magnetization via the exchange interaction. The direction of the domain-wall motion can be controlled using the helicity of the laser. Second, the domain wall is attracted to the hot spot generated by the focused laser. Unlike magnetic-field-driven domain-wall depinning, these mechanisms directly drive domain-wall motion, providing an optical tweezerlike ability to position and locally probe domain walls

What are shared and social values of ecosystems?

The theoretical framework outlined in this paper was developed initially through a series of expert workshops as part of the Valuing Nature Network — BRIDGE: From Values to Decisions project, funded by the UK Natural Environment Research Council (NERC). It was developed further through the follow-on phase of the UK National Ecosystem Assessment (Work Package 6: Shared, Plural and Cultural Values) funded by the UK Department of the Environment, Food and Rural Affairs (Defra), the Welsh Government, NERC, the Economic and Social Research Council (ESRC), and the Arts and Humanities Research Council (AHRC).Peer reviewedPublisher PD

Dimensionless cosmology

Although it is well known that any consideration of the variations of fundamental constants should be restricted to their dimensionless combinations, the literature on variations of the gravitational constant $G$ is entirely dimensionful. To illustrate applications of this to cosmology, we explicitly give a dimensionless version of the parameters of the standard cosmological model, and describe the physics of Big Bang Neucleosynthesis and recombination in a dimensionless manner. The issue that appears to have been missed in many studies is that in cosmology the strength of gravity is bound up in the cosmological equations, and the epoch at which we live is a crucial part of the model. We argue that it is useful to consider the hypothetical situation of communicating with another civilization (with entirely different units), comparing only dimensionless constants, in order to decide if we live in a Universe governed by precisely the same physical laws. In this thought experiment, we would also have to compare epochs, which can be defined by giving the value of any {\it one} of the evolving cosmological parameters. By setting things up carefully in this way one can avoid inconsistent results when considering variable constants, caused by effectively fixing more than one parameter today. We show examples of this effect by considering microwave background anisotropies, being careful to maintain dimensionlessness throughout. We present Fisher matrix calculations to estimate how well the fine structure constants for electromagnetism and gravity can be determined with future microwave background experiments. We highlight how one can be misled by simply adding $G$ to the usual cosmological parameter set

In-beam γ-ray spectroscopy of the proton emitter 147 69Tm using recoil-decay tagging

Gamma rays from the decay of states in the proton unstable nucleus 147Tm were observed for the first time following the 92Mo(58Ni,p2n! 147Tm reaction at 260 MeV. Prompt g rays were detected with an array of Compton-suppressed Ge detectors, placed in front of the fragment mass analyzer at the ATLAS accelerator, and were assigned to individual reaction channels on an event-by-event basis using the recoil-decay tagging method. Gamma-ray transitions were associated with both the proton decay of the ph11/2 ground state and the pd3/2 isomeric state in 147Tm, even though the cross sections for populating these states were only ' 16 mb and 2 mb, respectively. The level scheme which was constructed for 147Tm is discussed and compared with the level structures for lighter N578 isotones