People-Environment Trade-offs in Managing Communal Rangelands of South Africa

Communal rangelands in South Africa support a range of ecosystem services including water provision, carbon sequestration and livestock production for different stakeholders. Delivering these in a sustainable and socially appropriate manner necessarily requires trade-offs to be made between the different environmental and social outcomes required. We draw on empirical fieldwork and a two-day participatory stakeholder workshop to report on the early stages of a project evaluating these trade-offs in communal rangelands of the uMzimvubu catchment in Eastern Cape Province. Our findings suggest that trade-offs will be necessary at a variety of different levels within this system. For example, a key activity within these rangelands is removal of invasive plants such as wattle (Acacia mearnsii) but the environmental gains are conflictual as although this increases water availability within the system, it potentially reduces stored carbon. Wattle removal also highlights a disconnection between people and policy. While current policy mandates complete eradication of wattle, none of the local communities involved in the research wished to see this, as most of them currently make use of the trees for a range of purposes including timber, fuelwood and even livestock feed. Furthermore, trade-offs are also required between different community members, in terms of the social outcomes rangelands can deliver for them. While men conceptualised rangelands largely in terms of maximising livestock production, women focused on the collection of natural resources such as timber, herbs and thatching grass, the latter requiring accumulation of biomass during the growing season and potentially removing areas of rangeland from grazing. Understanding the opposing goals for rangeland use that exist within and between different stakeholder groups is critical to evaluating the social and environmental trade-offs required and to reach a consensus approach to the governance and management of these systems

ELAV links paused Pol II to alternative polyadenylation in the Drosophila nervious system

Alternative polyadenylation (APA) has been implicated in a variety of developmental and disease processes. A particularly dramatic form of APA occurs in the developing nervous system of flies and mammals, whereby various developmental genes undergo coordinate 3' UTR extension. In Drosophila, the RNA-binding protein ELAV inhibits RNA processing at proximal polyadenylation sites, thereby fostering the formation of exceptionally long 3' UTRs. Here, we present evidence that paused Pol II promotes recruitment of ELAV to extended genes. Replacing promoters of extended genes with heterologous promoters blocks normal 3' extension in the nervous system, while extension-associated promoters can induce 3' extension in ectopic tissues expressing ELAV. Computational analyses suggest that promoter regions of extended genes tend to contain paused Pol II and associated cis-regulatory elements such as GAGA. ChIP-seq assays identify ELAV in the promoter regions of extended genes. Our study provides evidence for a regulatory link between promoter-proximal pausing and APA

Quasispecies evolution in general mean-field landscapes

I consider a class of fitness landscapes, in which the fitness is a function of a finite number of phenotypic "traits", which are themselves linear functions of the genotype. I show that the stationary trait distribution in such a landscape can be explicitly evaluated in a suitably defined "thermodynamic limit", which is a combination of infinite-genome and strong selection limits. These considerations can be applied in particular to identify relevant features of the evolution of promoter binding sites, in spite of the shortness of the corresponding sequences.Comment: 6 pages, 2 figures, Europhysics Letters style (included) Finite-size scaling analysis sketched. To appear in Europhysics Letter

Role of Solvent Compatibility in the Phase Behavior of Binary Solutions of Weakly Associating Multivalent Polymers

[Image: see text] Condensate formation of biopolymer solutions, prominently those of various intrinsically disordered proteins (IDPs), is often driven by “sticky” interactions between associating residues, multivalently present along the polymer backbone. Using a ternary mean-field “stickers-and-spacers” model, we demonstrate that if sticker association is of the order of a few times the thermal energy, a delicate balance between specific binding and nonspecific polymer–solvent interactions gives rise to a particularly rich ternary phase behavior under physiological circumstances. For a generic system represented by a solution comprising multiassociative scaffold and client polymers, the difference in solvent compatibility between the polymers modulates the nature of isothermal liquid–liquid phase separation (LLPS) between associative and segregative. The calculations reveal regimes of dualistic phase behavior, where both types of LLPS occur within the same phase diagram, either associated with the presence of multiple miscibility gaps or a flip in the slope of the tie-lines belonging to a single coexistence region

Microfluidic cultivation and analysis of productive biofilms

We here report the application of a machine-based microfluidic biofilm cultivation and analysis platform for studying the performance of biocatalytically active biofilms. By using robotic sampling, we succeeded in spatially resolving the productivity of three microfluidic reactors containing biocatalytically active biofilms that inducibly overexpress recombinant enzymes. Escherichia coli biofilms expressing two stereoselective oxidoreductases, the (R)-selective alcohol dehydrogenase LbADH and the (S)-selective ketoreductase Gre2p, as well as the phenolic acid decarboxylase EsPAD were used. The excellent reproducibility of the cultivation and analysis methods observed for all three systems underlines the usefulness of the new technical platform for the investigation of biofilms. In addition, we demonstrated that the analytical platform also opens up new opportunities to perform in-depth spatially resolved studies on the biomass growth in a reactor channel and its biochemical productivity. Since the platform not only offers the detailed biochemical characterization but also broad capabilities for the morphological study of living biofilms, we believe that our approach can also be performed on many other natural and artificial biofilms to systematically investigate a wide range of process parameters in a highly parallel manner using miniaturized model systems, thus advancing the harnessing of microbial communities for technical purposes

Vanishing Fe 3d orbital moments in single-crystalline magnetite

We show detailed magnetic absorption spectroscopy results of an in situ cleaved high quality single crystal of magnetite. In addition the experimental setup was carefully optimized to reduce drift, self absorption, and offset phenomena as far as possible. In strong contradiction to recently published data, our observed orbital moments are nearly vanishing and the spin moments are quite close to the integer values proposed by theory. This very important issue supports the half metallic full spin polarized picture of magnetite.Comment: 7 pages, 4 figure

Frequency evaluation of the doubly forbidden 1S0→3P0^1S_0\to ^3P_0 transition in bosonic 174^{174}Yb

We report an uncertainty evaluation of an optical lattice clock based on the $^1S_0\leftrightarrow^3P_0$ transition in the bosonic isotope $^{174}$Yb by use of magnetically induced spectroscopy. The absolute frequency of the $^1S_0\leftrightarrow^3P_0$ transition has been determined through comparisons with optical and microwave standards at NIST. The weighted mean of the evaluations is $\nu$($^{174}$Yb)=518 294 025 309 217.8(0.9) Hz. The uncertainty due to systematic effects has been reduced to less than 0.8 Hz, which represents $1.5\times10^{-15}$ in fractional frequency.Comment: 4 pages, 3 figure -Submitted to PRA Rapid Communication

Accessibility and suitability of residential alcohol treatment for older adults: a mixed method study

Background Whilst alcohol misuse is decreasing amongst younger adults in many countries, it is increasing in older adults. Residential rehabilitation (rehab) is a vital component of the alcohol treatment system, particularly for those with relatively complex needs and entrenched alcohol problems. In this study, we sought to find out to what extent rehabs in England have upper age limits that exclude older adults, whether rehabs are responsive to older adults’ age-related needs and how older adults experience these services. Method This is a mixed method study. A search was carried out of Public Health England’s online directory of rehabs to identify upper age thresholds. Semi-structured qualitative interviews were carried out with 16 individuals who had attended one of five residential rehabs in England and Wales since their 50th birthday. A researcher with experience of a later life alcohol problem conducted the interviews. Results Of the 118 services listed on Public Health England’s online directory of rehabs, 75% stated that they had an upper age limit that would exclude older adults. Perceived differences in values, attitudes and behaviour between younger and older residents had an impact on older residents’ experience of rehab. Activities organised by the rehabs were often based on physical activity that some older adults found it difficult to take part in and this could create a sense of isolation. Some older adults felt unsafe in rehab and were bullied, intimidated and subjected to ageist language and attitudes. Conclusion This study identified direct and indirect age discrimination in rehabs contrary to the law. Further research is required to find out if age discrimination exists in rehabs in other countries. Rehabs should remove arbitrary age limits and ensure that they are responsive to the needs of older adults