A Note on Fractional KdV Hierarchies

We introduce a hierarchy of mutually commuting dynamical systems on a finite number of Laurent series. This hierarchy can be seen as a prolongation of the KP hierarchy, or a ``reduction'' in which the space coordinate is identified with an arbitrarily chosen time of a bigger dynamical system. Fractional KdV hierarchies are gotten by means of further reductions, obtained by constraining the Laurent series. The case of sl(3)^2 and its bihamiltonian structure are discussed in detail.Comment: Final version to appear in J. Math. Phys. Some changes in the order of presentation, with more emphasis on the geometrical picture. One figure added (using epsf.sty). 30 pages, Late

Instability, growth and economic performance: evidence of 17 Latin American countries 1980-2014

El trabajo estudia el efecto de la inestabilidad económica sobre el crecimiento en 17 países de Latinoamérica en el período 1980-2014 para tres diferentes grupos de crecimiento económico: bajo, medio y alto. La hipótesis es que una economía más inestable, es decir, con mayor inflación y volatilidad del producto perjudica a la inversión y, por tanto, al crecimiento. Para contrastar esta hipótesis se estima un modelo de efectos aleatorios usando un panel de 17 países de América Latina de un período de 35 años, en el cual se clasifican los países de acuerdo con el método de clúster de k-medianas. Los resultados indican que la inestabilidad afecta negativamente el desempeño económico de la región, en particular en los países de menor crecimiento. Por tanto, en estos casos se recomienda la aplicación de políticas anticíclicas y anti-inflacionarias.This paper studies the effect of economic stability on the growth of 17 Latin American countries between 1980-2014 for three different economic growth groups; low, middle and high. The hypothesis is that a more unstable economy, meaning, a larger inflation and product volatility, negatively affects investments, which affects growth. In order to contrast this hypothesis, a random effect model is estimated using a panel of 17 Latin American countries in a 35-year period, in which countries are classified according to the k-median cluster method. Results indicate that instability affects negatively the economic performance of the region, particularly countries with a smaller growth. Because of this, the recommendation for such cases is the application of anti-cyclic and anti-inflationary policies.O trabalho estuda o efeito da instabilidade econômica sobre o crescimento em 17 países da Latino-américa no período 1980-2014 para três diferentes grupos de crescimento econômico: baixo, médio e alto. a hipótese é que uma economia mais instável, ou seja com maior inflação e volatilidade do produto, prejudica ao investimento e por tanto ao crescimento. Para contrastar esta hipótese se estima um modelo de efeitos aleatórios usando um painel de 17 países da América Latina de um período de 35 anos, no qual se classificam os países de acordo ao método de clúster de k-medianas. Os resultados indicam que a instabilidade afeta negativamente o desempenho econômico da região, em particular nos países de menor crescimento. Por tanto, nestes casos se recomenda a aplicação de políticas anticíclicas e anti-inflacionárias

The operational effectiveness of the forest nursery sector in Leyte, The Philippines

Current programs and policies on forest management in the Philippines are biased towards the promotion of small-scale forestry. However, the scaling-up of smallholder forestry is hampered by the limited availability of planting materials and the low quality of planting stock. A study of the operational effectiveness of the forest nursery sector in the province of Leyte reveals that the operation of the nursery industry is not well-organized. The support provided by assisting agencies failed to promote the sustainability of smallholder nurseries. While a decentralized nursery management is widely perceived as the best alternative for reaching smallholders with planting stock, transferring the seedling production to smallholder nurseries needs strong collaboration with and support from the government nursery group. It is imperative for the government nursery group to refine its production objectives, operation schemes, types of assistance extended to smallholders and the means of extending the support to make it attuned to the needs and constraints of the smallholder nursery group

Small-Scale Forestry Development in Leyte, the Philippines: The Central Role of Nurseries

This paper presents results of survey research into the role of the forestry nursery sector in the development of smallholder forestry in Leyte, the Philippines. Seedling production in the province is basically carried out by three categories of nurseries: individual, communal and the government. Seedlings in the government nurseries are primarily raised for free distribution to landholders but the extension scheme fails to reach the majority of the smallholder farmers. Seedling demand of landholders is mostly catered for by the more numerous and accessible individual and communal nurseries. However, problems of capital outlay, sources and supply of germplasm, technical knowledge in nursery management for both timber and fruit trees and low sales are among the major impediments in the sustainability of small-scale nurseries. Most of the communal nurseries fail to sustain the operation after the withdrawal of supporting agencies. Knowledge of site-species matching is needed not only by small-scale nursery operators but also by the managers of government nurseries. It is concluded that the seedling industry in the province is not well established and there is a need to organise better the overall nursery system so as to improve the availability of seedlings and promote appropriate site and species combinations

The Potential Role of Nurseries in Improving Access to High Quality Planting Stock and Promoting Appropriate Silvicultural Systems to Improve the Productivity of Smallholder Tree Farms in Leyte, the Philippines

Constraints on availability of high-quality planting stock, improper matching of the species to the planting site and low level of silviculture hamper the success of smallholder tree plantings in Leyte. In spite of the available technologies in nursery and plantation management, smallholders still lack the necessary technical skills. This suggests that insufficient efforts are exerted by concerned agencies in extending the knowledge to the level of smallholders and it is indeed imperative to design means by which this pool of information can be disseminated. Inasmuch as most tree planting activities involve the establishment of nurseries, use of the nursery sector as a focal point of extension warrants investigation. Potential intervention measures including establishment of model smallholder nurseries to showcase the nursery cultural practices, creating a farmer-based seed distribution network to facilitate the distribution of germplasm and widen the species base, and accrediting the nurseries to improve sales, are suggested. These measures are designed to solve the previously identified problems ultimately promoting a wider adoption of smallholder forestry in the province and eventually in other regions of the country

Establishing field trials to promote smallholder forestry in Leyte, The Philippines

The quality of planting material is one of the key factors that determine the success of tree farming and reforestation activities. In the Philippines, low quality seedlings are commonly used in smallholder plantings for reasons such as the limited supply of high quality seedlings and smallholders’ lack of awareness of the benefits of using high quality planting stock. The ACIAR-funded seedling enhancement project has been carrying out training and extension activities to enhance the knowledge of tree farmers about the importance of high quality planting material and improve the capacity of nursery operators in the production of high quality seedlings. Various field trials were established to gain new knowledge on tree farming and to demonstrate to smallholders the result of adopting the best management practices

Germplasm Access and Planting Stock Quality in Smallholder Forest Nurseries in Leyte, the Philippines

This paper presents the results of a study investigating the germplasm access and quality of planting stocks in the smallholder nursery sector in the province of Leyte, the Philippines. Data were gathered through personal interview and analysed using the SPSS program. A total of 59 smallholder nursery operators and 15 government personnel involved in managing government nurseries were interviewed. Government nurseries were established primarily to provide planting stocks to smallholder tree farmers; however, the farmers either individually or in groups are raising seedlings to meet their own planting stock requirement. The type of species produced is largely determined by species availability. There is no free flow of information on germplasm sources resulting in inefficient distribution and utilisation of available species. This has resulted in the wide production of a few common exotics. Less emphasis is given on the use of genetically superior germplasm due to lack of information on a good-practice germplasm collection protocol and limited access to certified sources. The germplasm pathway in smallholder nursery system operates with a very weak link to agencies dealing with high quality planting materials. High quality germplasm enters the system but in a sporadic and uncontrolled way. Although smallholders possess the basic knowledge of nursery seedling culture, the planting stocks raised are of low quality suggesting the need to refine their skills in seedling production

Initial gas exchange results from field trials

Gas exchange measurements were undertaken at field trials to investigate the impact of thinning of 12 year old gmelina plantations located at Bato. Amax for leaves at the thinned site were significantly higher (pnarra>mahogany>mayapis. This pattern is also reflected in the average height of each species but not in the pattern for average biomass (number of leaves) and dbh which followed the pattern of falcata>mahogany>narra>mayapis. The reversal of mahogany and narra suggests a different pattern of resource allocation. Narra has high rates of Amax with a smaller number of leaves compared with mahogany which has a lower rate of Amax but a much greater number of leaves and total leaf biomass. There was a substantial difference between the light curves for 11 month old gmelina trees in the three experiment plots with a 3 m x 3 m spacing compared with gmelina trees in the one experimental plot with a 4 m x 4 m spacing (Figure 6). The preliminary interpretation of these results is that at even a very early age, resources are becoming limiting for photosynthesis at a 3 m x 3 m spacing. This unexpected finding will be investigated further with a variable spacing trial

A submillimeter search for pre- and proto-brown dwarfs in Chamaeleon II

Context. Chamaeleon II molecular cloud is an active star forming region that offers an excellent opportunity for studying the formation of brown dwarfs in the southern hemisphere. Aims. Our aims are to identify a population of pre- and proto- brown dwarfs (5 sigma mass limit threshold of ~0.015 Msun) and provide information on the formation mechanisms of substellar objects. Methods. We performed high sensitivity observations at 870 microns using the LABOCA bolometer at the APEX telescope towards an active star forming region in Chamaeleon II. The data are complemented with an extensive multiwavelength catalogue of sources from the optical to the far-infrared to study the nature of the LABOCA detections. Results. We detect fifteen cores at 870 microns, and eleven of them show masses in the substellar regime. The most intense objects in the surveyed field correspond to the submillimeter counterparts of the well known young stellar objects DK Cha and IRAS 12500-7658. We identify a possible proto-brown dwarf candidate (ChaII-APEX-L) with IRAC emission at 3.6 and 4.5 microns. Conclusions. Our analysis indicates that most of the spatially resolved cores are transient, and that the point-like starless cores in the sub-stellar regime (with masses between 0.016 Msun and 0.066 Msun) could be pre-brown dwarfs cores gravitationally unstable if they have radii smaller than 220 AU to 907 AU (1.2" to 5" at 178 pc) respectively for different masses. ALMA observations will be the key to reveal the energetic state of these pre-brown dwarfs candidates.Comment: 11 pages, 6 figure