The pion-kaon scattering amplitude constrained with forward dispersion relations up to 1.6 GeV

In this work we provide simple and precise parameterizations of the existing $\pi K$ scattering data from threshold up to 1.6 GeV, which are constrained to satisfy forward dispersion relations as well as three additional threshold sum rules. We also provide phenomenological values of the threshold parameters and of the resonance poles that appear in elastic scattering.Comment: References and comments added. Some errata corrected. Results unchanged. Version accepted for publication in Phys. Rev.

Strange resonance poles from KπK\pi scattering below 1.8 GeV

In this work we present a determination of the mass, width and coupling of the resonances that appear in kaon-pion scattering below 1.8 GeV. These are: the much debated scalar $\kappa$-meson, nowdays known as $K_0^*(800)$, the scalar $K_0^*(1430)$, the $K^*(892)$ and $K_1^*(1410)$ vectors, the spin-two $K_2^*(1430)$ as well as the spin-three $K^*_3(1780)$. The parameters will be determined from the pole associated to each resonance by means of an analytic continuation of the $K\pi$ scattering amplitudes obtained in a recent and precise data analysis constrained with dispersion relations, which were not well satisfied in previous analyses. This analytic continuation will be performed by means of Pad\'e approximants, thus avoiding a particular model for the pole parameterization. We also pay particular attention to the evaluation of uncertainties.Comment: 13 pages, 12 figures. Accepted version to appear in Eur. Phys. J. C. Clarifications and references added, minor typos correcte

ππ→KKˉ\pi \pi \rightarrow K \bar{K} scattering up to 1.47 GeV with hyperbolic dispersion relations

In this work we provide a dispersive analysis of $\pi\pi \rightarrow K\bar{K}$ scattering. For this purpose we present a set of partial-wave hyperbolic dispersion relations using a family of hyperbolas that maximizes the applicability range of the hyperbolic dispersive representation, which we have extended up to 1.47 GeV. We then use these equations first to test simple fits to different and often conflicting data sets, also showing that some of these data and some popular parameterizations of these waves fail to satisfy the dispersive analysis. Our main result is obtained after imposing these new relations as constraints on the data fits. We thus provide simple and precise parameterizations for the S, P and D waves that describe the experimental data from $K\bar K$ threshold up to 2 GeV, while being consistent with crossing symmetric partial-wave dispersion relations up to their maximum applicability range of 1.47 GeV. For the $S$-wave we have found that two solutions describing two conflicting data sets are possible. The dispersion relations also provide a representation for $S$, $P$ and $D$ waves in the pseudo-physical region.Comment: 27 pages, 19 figures. Errata corrected and references added. Version to appear in Eur. Phys. J.

Incidence of Trypanosoma cruzi infection in two Guatemalan communities.

The prevalence of human infection by Trypanosoma cruzi was assessed using an enzyme-linked immunosorbent assay (ELISA) in a serological survey in 1998 of 2 rural communities (SMH and PS) in Guatemala. In SMH (Department of Zacapa), where Rhodnius prolixus was the principal vector, the seroprevalence amongst 373 people tested was 38.8%. In PS (Department of Santa Rosa), where the main vector was Triatoma dimidiata, 8.9% of the 428 people tested were seropositive. The overall prevalence of seropositivity was higher in females than in males in both SMH (40% vs 36%) and PS (11.9% vs 4.9%), although this difference was significant only in PS. Historical seroconversion rates, estimated retrospectively by fitting a transmission model to the age-prevalence curves, were 3.8% per year in SMH and 0.5% per year in PS. There was some indication of a recent reduction in incidence in both villages. In PS, but not in SMH, both the observed prevalence and the estimated incidence rates were significantly higher in females than in males

Prosperity prospects in contested forest areas: evidence from community forestry development in Guatemala and Nicaragua

Tropentag, September 18-21, 2016, Vienna, Austria “Solidarity in a competing world — fair use of resources” Prosperity Prospects in Contested Forest Areas: Evidence from Community Forestry Development in Guatemala and Nicaragua Dietmar Stoian 1 , Aldo Rodas 2 , Jessenia Arguello 3 1 Bioversity International, Healthy Diets from Sustainable Food Systems Initiative, France 2 Ministry of Agriculture and Livestock, Guatemala, Natural Resources and Agrotourism, 3 Independent Consultant, Abstract Community forestry is carried out under diverse institutional, environmental, and socio-economic conditions. Local communities may have de jure rights to forest resources, but de facto protection is often weak. This study focuses on 25-year community concessions in the Maya Biosphere Reserve (MBR) in Guatemala and indigenous territories in the North Caribbean Coast Autonomous Region (RACCN), Nicaragua. In both cases, communities are struggling to enforce their rights as powerful external groups seek to expand cattle ranching, cash crops, tourism, and oil exploration. We found evidence that community forestry can generate significant socio-economic benefits that, along with contributions to forest conservation, substantiate the communities’ claim for strengthened and extended community forest stewardship. We selected six community forest enterprises (CFEs) along a business development gradient and assessed their context, economic viability, and livelihood benefits among randomly selected CFE members (n=180). Adopting an asset lens, we determined human, social, natural, physical and financial capital endowments at household and enterprise levels. Enterprise assets varied widely, both within and across countries. CFEs were well endowed with natural capital (7,000–54,000 ha of broadleaf forests) but highly dependent on precious woods, such as mahogany ( Swietenia macropylla ) or andiroba ( Carapa guianensis ). Human capital was sufficiently developed for managing forests, but less so for processing wood and doing business. Social capital has been built in Guatemala through internal organisation, bringing CFEs under the umbrella of a regional association, and developing relationships with buyers. In Nicaragua, however, building of social capital has been insufficient for inducing a self-sustaining process of CFE development. Physical capital for logging and wood processing was moderate but, in Guatemala, conditions facilitate significant value adding. CFEs there were profitable, while those in the RACCN struggled to break even. Household assets varied widely but, in the MBR, we found evidence that forest-based income can lift people out of poverty. Our analyses reveal that critical success factors for community forestry to reduce poverty, conserve forests and enhance equity are: secure long-term forest usufruct rights or ownership, efficient business organisation, credible advocacy, a conducive service environment, and differentiated opportunities for women, men and youth