An Event Structure Model for Probabilistic Concurrent Kleene Algebra

We give a new true-concurrent model for probabilistic concurrent Kleene algebra. The model is based on probabilistic event structures, which combines ideas from Katoen's work on probabilistic concurrency and Varacca's probabilistic prime event structures. The event structures are compared with a true-concurrent version of Segala's probabilistic simulation. Finally, the algebraic properties of the model are summarised to the extent that they can be used to derive techniques such as probabilistic rely/guarantee inference rules.Comment: Submitted and accepted for LPAR19 (2013

A Logic with Reverse Modalities for History-preserving Bisimulations

We introduce event identifier logic (EIL) which extends Hennessy-Milner logic by the addition of (1) reverse as well as forward modalities, and (2) identifiers to keep track of events. We show that this logic corresponds to hereditary history-preserving (HH) bisimulation equivalence within a particular true-concurrency model, namely stable configuration structures. We furthermore show how natural sublogics of EIL correspond to coarser equivalences. In particular we provide logical characterisations of weak history-preserving (WH) and history-preserving (H) bisimulation. Logics corresponding to HH and H bisimulation have been given previously, but not to WH bisimulation (when autoconcurrency is allowed), as far as we are aware. We also present characteristic formulas which characterise individual structures with respect to history-preserving equivalences.Comment: In Proceedings EXPRESS 2011, arXiv:1108.407

Management of Non Timber Forest Products (NTFPs) across the Nam Khan Watershed

This study on the use of Non Timber Forest Products (NTFPs) in the Nam Khan Watershed was conducted through household surveys and focus group discussions in three villages selected along a gradient of integration to market, and diversity of livelihood systems: Houayyen and Tinpha villages in Xieng Ngeun district and Longlet village in Phonxay district, Luang Prabang province. The main objectives of this research were to assess the value and uses of NTFPs by local farmers and to compare NTFPs management strategies between accessible and remote areas. This research revealed contrasted NTFPs management strategies between accessible areas and remote areas. More NTFPs species are collected in remote areas than in accessible areas but a bigger quantity is collected in accessible areas. In the remote areas, NTFPs are mainly consumed because of poor market accessibility, while most NTFPs collected in accessible areas are sold on the market. The diversity of NTFPs species available in the landscape influences local household management less than the possibility to get access to market. As a consequence, bigger volumes of a few species are collected in accessible areas for income generation while limited volume of more diverse species are collected in remote areas for food security. In remote areas, NTFPs are primarily collected in forests and old fallows while people in accessible areas have to collect NTFPs in young fallows that are individually appropriated and on agricultural land. Some commercial species (e.g. posaa, khem, peuakmeuak) are gradually domesticated as forest and old fallow patches get smaller, fragmented and scarce in the landscape. Sustainable management about NTFPs across the Nam Khan watershed should integrate conservation – development objectives at the watershed scale by increased exchanges between upstream and downstream villages and with the emerging markets. Sustainable NTFPs management plans should be designed not only at the village level but also at higher administrative levels (e.g. kumban, district, province, watershed) to tackle both environmental and livelihood issues. Protection of wildlife and biodiversity requires a better access to formal education in remote areas and environmental awareness in accessible areas

Implications of the calf musculature and Achilles tendon architectures for understanding the site of injury

Clinically the sites of Achilles Tendon (AT) overuse conditions can be divided into the tendon mid-portion and osteotendinous attachment. Purpose: We propose an anatomical analysis of the triceps surae musculotendon unit that could provide a possible anatomic explanation for these 2 sites of injury. Method: Twelve cadavers (age 74±7 years) were studied. In both legs, calf muscles (lateral gastrocnemius (LG), medial gastrocnemius (MG) and soleus) were dissected and their volumes measured. Fine saw cuts were made in the sagittal plane, either side of the midline of the calcaneus. Each strip contained the distal part of the tendon and its insertion, together with the superior tuberosity of the calcaneus. Trabecular architecture was analyzed from X-rays taken with Faxitron radiography. Histological sections of the enthesis and the thickness of the uncalcified fibrocartilage and the subchondral plate were evaluated. A finite element model of tendon coupled to a rupture index was developed to investigate the AT response to mechanical load. Results: Muscle volume was highest for the soleus, followed by the MG, and LG. Within the AT, the soleus fibers occupy the antero-medial parts, the MG fibers form the posterior lateral layer, yet the LG head fibers retain the antero-lateral part. The quantity of bone and the apparent trabecular thickness at the enthesis were greatest in the central part of the enthesis. Thickness of calcified fibrocartilage tissue was significantly greater in the central part than medially (P=0.04) and laterally (P=0.03). Uncalcified fibrocartilage was significantly thicker medially than laterally (P=0.02). Finally, finite element analysis showed that AT mechanical stress increased with muscle load and converged at 4.6–7.9cm of the enthesis. Conclusion: Our data suggest that the triceps surae musculotendon unit is composed of anatomically distinct parts that undergo non-uniform mechanical loading. There are two sites where potentially tendon mechanical stress increases, the medial/central portions of the enthesis and the tendon midportion