New Understanding of Large Magellanic Cloud Structure, Dynamics and Orbit from Carbon Star Kinematics

We derive general expressions for the LMC velocity field which we fit to kinematical data for 1041 carbon stars. We demonstrate that all previous studies of LMC kinematics have made unnecessary over-simplifications that have led to incorrect estimates of important structural parameters. We compile and improve LMC proper motion estimates to support our analysis. We find that the kinematically determined position angle of the line of nodes is 129.9 +/- 6.0 deg. The LMC inclination changes at a rate di/dt = -103 +/- 61 deg/Gyr, a result of precession and nutation induced by Milky Way tidal torques. The LMC rotation curve V(R) has amplitude 49.8 +/- 15.9 km/s, 40% lower than what has previously (and incorrectly) been inferred from e.g. HI. The dynamical center of the carbon stars is consistent with the center of the bar and the center of the outer isophotes, but not with the HI kinematical center. The enclosed mass inside 8.9 kpc is (8.7 +/- 4.3) x 10^9 M_sun, more than half of which is due to a dark halo. The LMC has a larger vertical thickness than has traditionally been believed. Its V/sigma is less than the value for the Milky Way thick disk. We discuss the implications for the LMC self-lensing optical depth. We determine the LMC velocity and orbit in the Galactocentric rest frame and find it to be consistent with the range of velocities that has been predicted by models for the Magellanic Stream. The Milky Way dark halo must have mass >4.3 x 10^{11} M_sun and extent >39 kpc for the LMC to be bound. We predict the LMC proper motion velocity field, and discuss techniques for kinematical distance estimation. [ABRIDGED]Comment: 57 pages, LaTeX, with 11 PostScript figures. Submitted to the Astronomical Journa

Further evidence that gender matters for GHG mitigation in the dairy sector: Analysis of survey data from central Kenya highlights interactive effects of gender and farm management practices on milk yield and GHG emission intensity

Consumption of dairy products in Sub-Saharan Africa is projected to increase significantly in the coming decades. As production increases, there will be an increasing need to reduce the environmental impacts of dairy production. One way to reduce the carbon footprint of milk production is to increase productivity: more productive cows use a greater proportion of feed energy and protein intake for milk production than less productive cows. Because more milk is produced for a given level of feed intake, the carbon footprint of milk can be reduced. Productivity may be increased by a range of management practices, such as improved breeds, use of higher quality feeds, animal health interventions and more. Often these measures are implemented as technology packages. For example, stall-feeding often involves adoption of improved dairy breeds and changes in feed sources and feed quality. Adoption of more intensive management practices is commonly linked to increased commercialization so that intensive production remains profitable. While most smallholders sell to informal markets, linking smallholders to the formal market (e.g. cooperatives and processing firms) is also seen as one way to incentivize and enable increased milk production. Thus, Kenya’s proposed dairy NAMA intends to promote intensification of production practices on farm to increase milk yields, and link dairy farmers to cooperatives and formal sector milk processors to strengthen market-based incentives for increased milk production (SDL 2017)

Density and strength of ties in innovation networks: a competence and governance view.

innovation, networks

Presuppositions in Context: Constructing Bridges

About the book: The First International and Interdisciplinary Conference on Modelling and Using Context, Rio de Janeiro, January 1997, gave rise to the present book, which contains a selection of the papers presented there, thoroughly refereed and revised. The treatment of contexts as bona fide objects of logical formalisation has gained wide acceptance, following the seminal impetus given by McCarthy in his Turing Award address. The field of natural language offers a particularly rich variety of examples and challenges to researchers concerned with the formal modelling of context, and several chapters in the volume deal with contextualisation in the setting of natural language. Others adopt a purely formal-logical viewpoint, seeking to develop general models of even wider applicability. The 12 chapters are organised in three groups: formalisation of contextual information in natural language understanding and generation, the application of context in mechanised reasoning domains, and novel non-classical logics for contextual application

A probabilistic analysis of argument cogency

This paper offers a probabilistic treatment of the conditions for argument cogency as endorsed in informal logic: acceptability, relevance, and sufficiency. Treating a natural language argument as a reason-claim-complex, our analysis identifies content features of defeasible argument on which the RSA conditions depend, namely: change in the commitment to the reason, the reason’s sensitivity and selectivity to the claim, one’s prior commitment to the claim, and the contextually determined thresholds of acceptability for reasons and for claims. Results contrast with, and may indeed serve to correct, the informal understanding and applications of the RSA criteria concerning their conceptual dependence, their function as update-thresholds, and their status as obligatory rather than permissive norms, but also show how these formal and informal normative approachs can in fact align