Deforestation as an externality problem to be solved efficiently and fairly

The international community recently agreed on a mechanism called REDD+ to reduce deforestation in tropical countries. However the mechanism, by its very nature, has no reason to induce a Pareto optimal reduction of deforestation. The aim of this article is to propose an alternative class of mechanisms for negative externalities that implements Pareto optimal outcomes as Nash Subgame Perfect Equilibria, and that satisfies some fairness properties, in particular two original axioms of environmental responsibility. Outcomes are individually rational and the scheme does take into account environmental responsibility in the sense of our two axioms. However, envy freeness, even in a weak form adapted to the deforestation problem, turns out to be hard to achieve without dropping the other properties.

The REDD scheme to curb deforestation: A well-designed system of incentives?

Bioprospection is, largely, meant to help reducing deforestation and, the other way around, stopping deforestation enhances the prospects of bioprospection. The need for a global agreement to the problem of tropical deforestation has led to the REDD (Reducing Emissions from Deforestation and Degradation) scheme, which proposes that developed countries pay developing countries for CO2 emissions saved through avoided deforestation and degradation. The remaining issue at stake is to definer the rules defning payments to countries reducing their deforestation rate. This article develops a game-theoretic bargaining model, simulating the on-going negotiation process which is currently taking place within the Convention of Climate Change, after the Copenhagen agreement of December 2009. It shows that the conditions under which developing countries are left to bargain over the allocation of the global forest fund may lead to an ineffective system of incentives. Below a given level of contributions from the North, the mechanism fails to curb the deforestation. Beyond this level, it induces perverse effects: the larger the North's contribution, the larger the deforestation rate. Consequently, the mechanism is most effective only at a specifc threshold level which, given the unobservability of countries'preferences, can only be found by a repeated "trial and error" implementation process.

The lower mass function of the young open cluster Blanco 1: from 30 Mjup to 3 Mo

18 pages, 15 figures and 5 tables accepted in A&AWe performed a deep wide field optical survey of the young (~100-150 Myr) open cluster Blanco1 to study its low mass population well down into the brown dwarf regime and estimate its mass function over the whole cluster mass range.The survey covers 2.3 square degrees in the I and z-bands down to I~z~24 with the CFH12K camera. Considering two different cluster ages (100 and 150 Myr), we selected cluster member candidates on the basis of their location in the (I,I-z) CMD relative to the isochrones, and estimated the contamination by foreground late-type field dwarfs using statistical arguments, infrared photometry and low-resolution optical spectroscopy. We find that our survey should contain about 57% of the cluster members in the 0.03-0.6 Mo mass range, including 30-40 brown dwarfs. The candidate's radial distribution presents evidence that mass segregation has already occured in the cluster. We took it into account to estimate the cluster mass function across the stellar/substellar boundary. We find that, between 0.03Mo and 0.6Mo, the cluster mass distribution does not depend much on its exact age, and is well represented by a single power-law, with an index alpha=0.69 +/- 0.15. Over the whole mass domain, from 0.03Mo to 3Mo, the mass function is better fitted by a log-normal function with m0=0.36 +/- 0.07Mo and sigma=0.58 +/- 0.06. Comparison between the Blanco1 mass function, other young open clusters' MF, and the galactic disc MF suggests that the IMF, from the substellar domain to the higher mass part, does not depend much on initial conditions. We discuss the implications of this result on theories developed to date to explain the origin of the mass distribution

CAPAbility: Comparison of the JOURNEY II Bi-Cruciate Stabilised and GENESIS II total knee arthroplasty in performance and functional ability: protocol of a randomised controlled trial

Background: Osteoarthritis of the knee is a common condition that is expected to rise in the next two decades leading to an associated increase in total knee replacement (TKR) surgery. Although there is little debate regarding the safety and efficacy of modern TKR, up to 20% of patients report poor functional outcomes following surgery. This study will investigate the functional outcome of two TKRs; the JOURNEY II Bi-Cruciate Stabilised knee arthroplasty, a newer knee prosthesis designed to provide guided motion and improve knee kinematics by more closely approximating a normal knee, and the GENESIS II, a proven existing design. Aim: To compare the change in Patient-reported Outcome Measures (PROMs) scores of the JOURNEY II BCS and the GENESIS II from pre-operation to 6 months post operation. Methods: CAPAbility is a pragmatic, blinded, two-arm parallel, randomised controlled trial recruiting patients with primary osteoarthritis due to have unilateral TKR surgery across two UK hospitals. Eligible participants (n = 80) will be randomly allocated to receive either the JOURNEY II or the GENESIS II BCS knee prosthesis. Baseline measures will be taken prior to surgery. Patients will be followed at 1 week, 6 to 8 weeks and 6 months post-operatively. The primary outcome is the Oxford Knee Score (OKS) at 6 months post-operatively. Secondary outcomes include: Other PROMs, biomechanical, radiological (computerised tomography, (CT)), clinical efficacy and safety outcomes. An embedded qualitative study will also investigate patients' perspectives via interview pre and post surgery on variables known to affect the outcome of TKR surgery. A sub-sample (n = 30) will have additional in-depth interviews to explore the themes identified. The surgeons' perspectives on the operation will be investigated by a group interview after all participants have undergone surgery. Discussion: This trial will evaluate two generations of TKR using PROMS, kinematic and radiological analyses and qualitative outcomes from the patient perspective

Protein phosphatase 2A associates with and regulates atypical PKC and the epithelial tight junction complex

Tight junctions (TJs) play a crucial role in the establishment of cell polarity and regulation of paracellular permeability in epithelia. Here, we show that upon calcium-induced junction biogenesis in Madin-Darby canine kidney cells, ABαC, a major protein phosphatase (PP)2A holoenzyme, is recruited to the apical membrane where it interacts with the TJ complex. Enhanced PP2A activity induces dephosphorylation of the TJ proteins, ZO-1, occludin, and claudin-1, and is associated with increased paracellular permeability. Expression of PP2A catalytic subunit severely prevents TJ assembly. Conversely, inhibition of PP2A by okadaic acid promotes the phosphorylation and recruitment of ZO-1, occludin, and claudin-1 to the TJ during junctional biogenesis. PP2A negatively regulates TJ assembly without appreciably affecting the organization of F-actin and E-cadherin. Significantly, inhibition of atypical PKC (aPKC) blocks the calcium- and serum-independent membrane redistribution of TJ proteins induced by okadaic acid. Indeed, PP2A associates with and critically regulates the activity and distribution of aPKC during TJ formation. Thus, we provide the first evidence for calcium-dependent targeting of PP2A in epithelial cells, we identify PP2A as the first serine/threonine phosphatase associated with the multiprotein TJ complex, and we unveil a novel role for PP2A in the regulation of epithelial aPKC and TJ assembly and function

The influence of an inquiry-based approach on grade four learners' understanding of the particulate nature of matter in the gaseous phase : a case study

A qualitative pre-/post-test case study was conducted to explore the influence of inquiry-based education in eliciting learners’ understanding of the particulate nature of matter in the gaseous phase. Two grade four classes (n=116) were conveniently and purposively sampled from two farm schools in Pretoria, South Africa. Data was collected through pre-test, initial group interviews, post-test, final group interviews and field notes. The pre-intervention data indicated that the continuous, continuousanimistic and the continuous empty models of matter in the gaseous phase dominated learners’ understanding in all the four classes. A considerable decrease in the continuous model was observed in the inquiry classes rather than in the lecture classes post-intervention.The South African National Research Foundationhttps://www.ejmste.compm2021Science, Mathematics and Technology Educatio

Impact of cellulose ethers on the cement paste microstructure

ISBN = 3-87264-022-4 7 pagesInternational audienceComplementary investigation tools (2D and 3D observations by optical microscopy and fast X-ray microtomography and then image analysis) were developed in order to examine the effects of cellulose ethers on the cement paste microstructure. The obtained results show that the presence of cellulose ether may induce an increase of both 50-250 µm-diameter air voids. The chemistry of the cellulose ethers appears as a main controlling factor of this porous media modification. In particular, cellulose ethers seems to play an important role on the air bubbles morphological characteristics, the content of air volume and the stabilisation of the porosity from the fresh cement paste to the hardened cement paste

Spatial Areas of Genotype Probability of Cattle Genomic Variants Involved in the Resistance to East Coast Fever: A Tool to Predict Future Disease-Vulnerable Geographical Regions

East Coast Fever (ECF) is a livestock disease caused by Theileria parva, a protozoan transmitted by the vector tick Rhipicephalus appendiculatus. This disease causes high mortality in cattle populations of Central and Eastern Africa, especially in exotic breeds. Here, we highlight genomic regions likely involved into tolerance/resistance mechanisms against ECF, and we introduce the estimation of their Spatial Area of Genotype Probability (SPAG) to delimit areas where the concerned genotypes are predicted to be present. During the NEXTGEN project, 803 Ugandan cattle were geo-referenced and genotyped (54K SNPs), while 532 tick occurrences were retrieved from a published database. To get a proxy of the parasite selective pressure, we used WorldClim bioclimatic variables to model vector ecological niche. Landscape genomics models were then used to detect cattle genotypes associated with vector probability of presence, and to estimate their SPAGs. Finally, climate change scenarios for 2070 were considered to compare the predicted shift in the vector niche with the estimated current SPAG. The analysis revealed two main areas of presence of possibly resistance-related genotypes, one South and one East of Lake Victoria. Climate change will probably shift tick niche southwards in the Eastern regions of Lake Victoria, inducing a critical area that currently does not show the candidate genotypes, but where disease will likely spread in the future. The combined use of SPAGs and niche maps could therefore facilitate the identification of regions of concern and to direct future targeted breeding schemes

Effect of climate change on the spatial distribution of genomic variants involved in the resistance to East Coast Fever in Ugandan cattle

East Coast Fever (ECF) is a major livestock disease caused by Theileria parva Theiler, 1904, an emo-parasite protozoan transmitted by the tick Rhipicephalus appendiculatus Neumann, 1901. This disease provokes high mortality in cattle populations of East and Central Africa, especially in exotic breeds and crossbreds (Olwoch et al., 2008). Here, we use landscape genomics (Joost et al., 2007) to highlight genomic regions likely involved into tolerance/resistance mechanisms against ECF, and we introduce Spatial Areas of Genotype Probability (SPAG) to delimit territories where favourable allelic variants are predicted to be present. Between 2010 and 2012, the NEXTGEN project (nextgen.epfl.ch) carried out the geo-referencing and genotyping (54K SNPs) of 803 Ugandan cattle, among which 496 were tested for T. parva presence. Moreover, 532 additional R. appendiculatus occurrences were obtained from a published database (Cumming, 1998). Current and future values of 19 bioclimatic variables were also retrieved from the WorldClim database (www.worldclim.org/). In order to evaluate the selective pressure of the parasite, we used MAXENT (Phillips et al., 2006; Muscarella et al., 2014) and a mixed logistic regression (Bates et al., 2014) to model and map the ecological niches of both T. parva and R. appendiculatus. Then, we used a correlative approach (Stucki et al., 2014) to detect molecular markers positively associated with the resulting probabilities of presence and built the corresponding SPAG. Finally, we considered bioclimatic predictors representing two different climate change scenarios for 2070 - one moderate and one severe - to forecast the simultaneous shift of both SPAG and vector/pathogen niches. While suitable ecological conditions for T. parva are predicted to remain constant, the best environment for the vector is predicted around Lake Victoria. However, when considering future conditions, parasite occurrence is expected to decrease because of the contraction of suitable environments for the tick in both scenarios. Landscape genomics’ analyses revealed several markers significantly associated with a high probability of presence of the tick and of the parasite. Among them, we found the marker ARS-BFGL-NGS-113888, whose heterozygous genotype AG showed a positive association. Interestingly, this marker is located close to the gene IRAK-M, an essential component of the Toll-like receptors involved in the immune response against pathogens (Kobayashi et al., 2002). If the implication of this gene into resistance mechanisms against ECF is confirmed, the corresponding SPAG (Figure 1) represents either areas where the variant of interest shows a high probability to exist now, or areas where ecological characteristics are the most favorable to induce its presence under future climatic conditions. Beyond the results presented here, the combined use of SPAG and niche maps could help identifying critical geographical regions that do not present the favourable genetic variant in the present, but where a parasite is likely to expand its range in the future. This may represent a valuable tool to support the identification of current resistant populations and to direct future targeted crossbreeding schemes

An Analysis of Private School Closings

We add to the small literature on private school supply by exploring exits of K-12 private schools. We find that the closure of private schools is not an infrequent event, and use national survey data from the National Center for Education Statistics to study closures of private schools. We assume that the probability of an exit is a function of excess supply of private schools over the demand, as well as the school's characteristics such as age, size, and religious affiliation. Our empirical results generally support the implications of the model. Working Paper 07-0