SDF-1 and PDGF enhance [alpha]v[beta]5-mediated ERK activation and adhesion-independent growth of human pre-B cell lines

CD23 acts through the [alpha]v[beta]5 integrin to promote growth of human pre-B cell lines in an adhesion-independent manner. [alpha]v[beta]5 is expressed on normal B-cell precursors in the bone marrow. Soluble CD23 (sCD23), short CD23-derived peptides containing the arg-lys-cys (RKC) motif recognized by [alpha]v[beta]5 and anti-[alpha]v[beta]5 monoclonal antibodies (MAbs) all sustain growth of pre-B cell lines. The chemokine stromal cell-derived factor-1 (SDF-1) regulates key processes during B-cell development. SDF-1 enhanced the growth-sustaining effect driven by ligation of [alpha]v[beta]5 with anti-[alpha]v[beta]5 MAb 15F-11, sCD23 or CD23-derived RKC-containing peptides. This effect was restricted to B-cell precursors and was specific to SDF-1. The enhancement in growth was associated with the activation of extracellular signal-regulated kinase (ERK) and both these responses were attenuated by the MEK inhibitor U0126. Finally, platelet-derived growth factor also enhanced both [alpha]v[beta]5-mediated cell growth and ERK activation. The data suggest that adhesion-independent growth-promoting signals delivered to B-cell precursors through the [alpha]v[beta]5 integrin can be modulated by cross-talk with receptors linked to both G-protein and tyrosine kinase-coupled signalling pathways

Exploring the Potential of Developmental Work Research and Change Laboratory to Support Sustainability Transformations:A Case Study of Organic Agriculture in Zimbabwe

This paper explores the emergence of transgressive learning in CHAT-informed development work research in a networked organic agriculture case study in Zimbabwe, based on intervention research involving district organic associations tackling interconnected issues of climate change, water, food security and solidarity. The study established that We change laboratories can be used to support transgressive learning through: confronting unproductive local norms; collective reframing of problematic issues; stimulating expansive learning and sustainability transformations in minds, relationships and landscapes across time. The study also confirms the need for fourth generation CHAT to address the complex social-ecological problems of today

Graviton n-point functions for UV-complete theories in Anti-de Sitter space

We calculate graviton n-point functions in an anti-de Sitter black brane background for effective gravity theories whose linearized equations of motion have at most two time derivatives. We compare the n-point functions in Einstein gravity to those in theories whose leading correction is quadratic in the Riemann tensor. The comparison is made for any number of gravitons and for all physical graviton modes in a kinematic region for which the leading correction can significantly modify the Einstein result. We find that the n-point functions of Einstein gravity depend on at most a single angle, whereas those of the corrected theories may depend on two angles. For the four-point functions, Einstein gravity exhibits linear dependence on the Mandelstam variable s versus a quadratic dependence on s for the corrected theory.Comment: 29 page

From Oral Literature to Technauriture: What’s in a Name?

Russell H. Kaschula is Professor of African Language Studies and Head of the School of Languages at Rhodes University, Grahamstown, South Africa. His doctoral research focussed on African literature, and his works of creative writing have received a number of prestigious literature and short story prizes. Professor Kaschula is an author of both English and isiXhosa academic and literary works, with novels including The Tsitsa River and Beyond and Mama, I Sing to You. In 2011, his short story Six Teaspoons of Sweetness was included in the International PEN-Studzinski award. Andre M. Mostert is a research associate at the School of Languages at Rhodes University, Grahamstown, South Africa, where he recently completed a master’s thesis on the literary work of the poet Bongani Sitole. Mostert’s interests focus on entrepreneurship and enterprise in schools, the use of ICT in education and training, and the role of ICT in promoting the capture and dissemination of oral poetry. Mostert is the gaming scientist for the EU Player project to support young entrepreneurs and, together with Professor Kaschula, co-developed the ‘publish and thrive’ model of supporting the research records of emerging academics.Oral traditions and oral literature have long contributed to human communication, yet the advent of arguably the most influential technology—the written word—altered the course of creative ability. Despite its potential and scope, the development of the written word resulted in an insidious dichotomy. As the written word evolved, the oral word became devalued and pushed to the fringes of society. One of the unfortunate consequences of this transition to writing has been a focus on the systems and conventions of orality and oral tradition. Although of importance, a more appropriate focus would be on ways of supporting and maintaining the oral word, and its innate value to human society, in the face of rampant technological development. Yet it is ironic that technology is also helping to create a fecund environment for the rebirth of orality. This paper offers an overview of the debate about the relationship between oral literature, the written word and technology, and suggests that the term technauriture may offer a suitable encompassing paradigm for further engagement with the oral word and its application to modern society. We discuss the late Bongani Sitole, a poet whose oral works were transformed into public and educational resources through the application of technology, and we consider the utility of the term technauriture for describing the relationship between orality, literature and technology

Collaborative stewardship in multifunctional landscapes: Toward relational, pluralistic approaches

Landscape stewardship offers a means to put social-ecological approaches to stewardship into practice. The growing interest in landscape stewardship has led to a focus on multistakeholder collaboration. Although there is a significant body of literature on collaborative management and governance of natural resources, the particular challenges posed by multifunctional landscapes, in which there are often contested interests, require closer attention. We present a case study from South Africa to investigate how collaborative stewardship can be fostered in contested multifunctional landscapes. We conducted this research through an engaged transdisciplinary research partnership in which we integrated social-ecological practitioner and academic knowledge to gain an in-depth understanding of the challenges of fostering collaboration. We identified five overarching factors that influence collaboration: contextual, institutional, social-relational, individual, and political-historical. Collaborative stewardship approaches focused on the development of formal governance institutions appear to be most successful if enabling individual and social-relational conditions are in place. Our case study, characterized by high social diversity, inequity, and contestation, suggests that consensus-driven approaches to collaboration are unlikely to result in equitable and sustainable landscape stewardship in such contexts. We therefore suggest an approach that focuses on enhancing individual and social-relational enablers. Moreover, we propose a bottom-up patchwork approach to collaborative stewardship premised on the notion of pluralism. This would focus on building new interpersonal relationships and collaborative capacity through small collective actions. Taking a relational, pluralistic approach to fostering collaborative stewardship is particularly important in contested, socially heterogeneous landscapes. Drawing on our study and the literature, we propose guiding principles for implementing relational, pluralistic approaches to collaborative stewardship and suggest future research directions for supporting such approaches

Intersections and differentiations: a corpus-assisted discourse study of gender representations in the British press before, during and after the London Olympics 2012

This study examines the impact of a global sports event on gender representations in media reporting. Whereas previous research on gender, sport and media has been mainly concerned with sports events in the North American or Australian context, this study investigates the British media reporting before, during and after the London Olympics 2012. Our study follows the approach of Corpus-Assisted Discourse Studies (CADS) and uses both quantitative and qualitative research procedures. The results reveal more balanced gender representations during the London Olympics in that the ‘regular’ biased associations were supressed in favour of positive references to female achievements. However, little carry-though of the ‘gains’ was noted. Also, this study shows that the positive associations intersected with national sentiments and were used to celebrate the nation-state. At the same time, some subtle resistance was observed to accepting as ‘truly’ British the non-white athletes and those not born in Britain

Age validation, growth, mortality, and demographic modeling of spotted gully shark (Triakis megalopterus) from the southeast coast of South Africa

This study documents validation of vertebral band-pair formation in spotted gully shark (Triakis megalopterus) with the use of fluorochrome injection and tagging of captive and wild sharks over a 21-year period. Growth and mortality rates of T. megalopterus were also estimated and a demographic analysis of the species was conducted. Of the 23 OTC (oxytetracycline) -marked vertebrae examined (12 from captive and 11 from wild sharks), seven vertebrae (three from captive and four from wild sharks) exhibited chelation of the OTC and fluoresced under ultraviolet light. It was concluded that a single opaque and translucent band pair was deposited annually up to at least 25 years of age, the maximum age recorded. Reader precision was assessed by using an index of average percent error calculated at 5%. No significant differences were found between male and female growth patterns (P>0.05), and von Bertalanffy growth model parameters for combined sexes were estimated to be L∞=1711.07 mm TL, k=0.11/yr and t0=–2.43 yr (n=86). Natural mortality was estimated at 0.17/yr. Age at maturity was estimated at 11 years for males and 15 years for females. Results of the demographic analysis showed that the population, in the absence of fishing mortality, was stable and not significantly different from zero and particularly sensitive to overfishing. At the current age at first capture and natural mortality rate, the fishing mortality rate required to result in negative population growth was low at F>0.004/ yr. Elasticity analysis revealed that juvenile survival was the principal factor in explaining variability in population growth rate

PRECEPT:a framework for ethical digital forensics investigations

Purpose: Cyber-enabled crimes are on the increase, and law enforcement has had to expand many of their detecting activities into the digital domain. As such, the field of digital forensics has become far more sophisticated over the years and is now able to uncover even more evidence that can be used to support prosecution of cyber criminals in a court of law. Governments, too, have embraced the ability to track suspicious individuals in the online world. Forensics investigators are driven to gather data exhaustively, being under pressure to provide law enforcement with sufficient evidence to secure a conviction. Yet, there are concerns about the ethics and justice of untrammeled investigations on a number of levels. On an organizational level, unconstrained investigations could interfere with, and damage, the organization’s right to control the disclosure of their intellectual capital. On an individual level, those being investigated could easily have their legal privacy rights violated by forensics investigations. On a societal level, there might be a sense of injustice at the perceived inequality of current practice in this domain. This paper argues the need for a practical, ethically-grounded approach to digital forensic investigations, one that acknowledges and respects the privacy rights of individuals and the intellectual capital disclosure rights of organisations, as well as acknowledging the needs of law enforcement. We derive a set of ethical guidelines, then map these onto a forensics investigation framework. We subjected the framework to expert review in two stages, refining the framework after each stage. We conclude by proposing the refined ethically-grounded digital forensics investigation framework. Our treatise is primarily UK based, but the concepts presented here have international relevance and applicability.Design methodology: In this paper, the lens of justice theory is used to explore the tension that exists between the needs of digital forensic investigations into cybercrimes on the one hand, and, on the other, individuals’ rights to privacy and organizations’ rights to control intellectual capital disclosure.Findings: The investigation revealed a potential inequality between the practices of digital forensics investigators and the rights of other stakeholders. That being so, the need for a more ethically-informed approach to digital forensics investigations, as a remedy, is highlighted, and a framework proposed to provide this.Practical Implications: Our proposed ethically-informed framework for guiding digital forensics investigations suggest a way of re-establishing the equality of the stakeholders in this arena, and ensuring that the potential for a sense of injustice is reduced.Originality/value: Justice theory is used to highlight the difficulties in squaring the circle between the rights and expectations of all stakeholders in the digital forensics arena. The outcome is the forensics investigation guideline, PRECEpt: Privacy-Respecting EthiCal framEwork, which provides the basis for a re-aligning of the balance between the requirements and expectations of digital forensic investigators on the one hand, and individual and organizational expectations and rights, on the other

Emplacement of inflated Pāhoehoe flows in the Naude’s Nek Pass, Lesotho remnant, Karoo continental flood basalt province: use of flow-lobe tumuli in understanding flood basalt emplacement

Physical volcanological features are presented for a 710-m-thick section, of the Naude’s Nek Pass, within the lower part of the Lesotho remnant of the Karoo Large Igneous Province. The section consists of inflated pāhoehoe lava with thin, impersistent sedimentary interbeds towards the base. There are seven discreet packages of compound and hummocky pāhoehoe lobes containing flow-lobe tumuli, making up approximately 50% of the section. Approximately 45% of the sequence consists of 14 sheet lobes, between 10 and 52-m-thick. The majority of the sheet lobes are in two packages indicating prolonged periods of lava supply capable of producing thick sheet lobes. The other sheet lobes are as individual lobes or pairs, within compound flows, suggesting brief increases in lava supply rate. We suggest, contrary to current belief, that there is no evidence that compound flows are proximal to source and sheet lobes (simple flows) are distal to source and we propose that the presence of flow-lobe tumuli in compound flows could be an indicator that a flow is distal to source. We use detailed, previously published, studies of the Thakurvadi Formation (Deccan Traps) as an example. We show that the length of a lobe and therefore the sections that are ‘medial or distal to source’ are specific to each individual lobe and are dependent on the lava supply of each eruptive event, and as such flow lobe tumuli can be used as an indicator of relative distance from source

Unitarity constraints on the ratio of shear viscosity to entropy density in higher derivative gravity

We discuss corrections to the ratio of shear viscosity to entropy density $\eta/s$ in higher-derivative gravity theories. Generically, these theories contain ghost modes with Planck-scale masses. Motivated by general considerations about unitarity, we propose new boundary conditions for the equations of motion of the graviton perturbations that force the amplitude of the ghosts modes to vanish. We analyze explicitly four-derivative perturbative corrections to Einstein gravity which generically lead to four-derivative equations of motion, compare our choice of boundary conditions to previous proposals and show that, with our new prescription, the ratio $\eta/s$ remains at the Einstein-gravity value of $1/4\pi$ to leading order in the corrections. It is argued that, when the new boundary conditions are imposed on six and higher-derivative equations of motion, $\eta/s$ can only increase from the Einstein-gravity value. We also recall some general arguments that support the validity of our results to all orders in the strength of the corrections to Einstein gravity. We then discuss the particular case of Gauss-Bonnet gravity, for which the equations of motion are only of two-derivative order and the value of $\eta/s$ can decrease below $1/4\pi$ when treated in a nonperturbative way. Our findings provide further evidence for the validity of the KSS bound for theories that can be viewed as perturbative corrections to Einstein Gravity.Comment: Sign error in the equations of motion corrected, leading to several numerical changes. Clarifications added, references added. Main results and cnclusions essentially unchanged. V3 published version. Clarifications added, discussion of Gauss-Bonnet moved to main tex