Out of Challenge, Opportunity: Central America's Electric Sector & Key Issues and Recommendations for Enhanced Regional Electric Integration

Taken together, the six nations of Central America count a population of roughly 40 million people and an energy market equal in size to that of Colombia, sufficient to benefit from economies of scale. The region has traditionally been a net importer of hydrocarbons, and hydroelectricity has dominated electric generation. But more recently, thermoelectric generation (diesel and fuel oil) has greatly increased as a percentage of the regional generation market. Progress has been made across the region’s electric sector, beginning with reforms in the 1990s and the 1996 signing of a regional treaty aimed at the development of a regional energy integration project – the Central American Electrical Interconnection System, or SIEPAC. A fundamental SIEPAC goal is to set up a regional electric market and a regulatory system. Indeed, after many years of development, SIEPAC is poised to open a new chapter in Central America’s electric infrastructure and market. But this new era must contend with critical issues such as the need to consolidate the regional electric market, political issues surrounding the venture, and security concerns. Moreover, local conflicts, in different degrees, have become priorities for policymakers, and these are possible barriers to completing the project. The goals of the SIEPAC project and of deepening the broader electric integration process are possible if national and regional decision makers understand that cooperative decision making will produce better results than separate national decision making. Enhanced regional understanding and cooperative decision making, combined with an effort to reorient the terminology and dialogue vis-à-vis energy efficiency in Central America, form the core recommendations of this paper.

The relationship between the use of Academic Text Talk and the comprehension of scientific academic language for diverse second graders

Changing demographics impact our schools as children come from more linguistically and culturally diverse backgrounds. The various social, cultural, and economic backgrounds of the students affect their early language learning experiences which expose them to the academic language needed to succeed in school. Teachers can help students acquire academic language by introducing words that are within their Zone of Proximal Development and increasing exposure to and use of academic language. This study investigated the effects of increasing structured activities for students to orally interact with informational text on their scientific academic language development and comprehension of expository text. ^ The Academic Text Talk activities, designed to scaffold verbalization of new words and ideas, included discussion, retelling, games, and sentence walls. This study also evaluated if there were differences in scientific language proficiency and comprehension between boys and girls, and between English language learners and native English speakers. ^ A quasi-experimental design was used to determine the relationship between increasing students' oral practice with academic language and their academic language proficiency. Second graders (n = 91) from an urban public school participated in two science units over an 8 week period and were pre and post tested using the Woodcock Muñoz Language Survey-Revised and vocabulary tests from the National Energy Education Project. Analysis of covariance was performed on the pre to post scores by treatment group to determine differences in academic language proficiency for students taught using Academic Text Talk compared to students taught using a text-centered method, using the initial Florida Assessment for Instruction in Reading test as a covariate. Students taught using Academic Text Talk multimodal strategies showed significantly greater increases in their pre to posttest means on the Woodcock Muñoz Language Survey-Revised Oral Language Totals and National Energy Education Development Project Vocabulary tests than students taught using the text-centered method, ps < .05. Boys did not show significantly greater increases than girls, nor did English language learners show significantly greater increases than the native English speakers. ^ This study informs the field of reading research by evaluating the effectiveness of a multimodal combination of strategies emphasizing discourse to build academic language.^

Summertime Influences of Tidal Energy Advection on the Surface Energy Balance in a Mangrove Forest

Mangrove forests are ecosystems susceptible to changing water levels and temperatures due to climate change as well as perturbations resulting from tropical storms. Numerical models can be used to project mangrove forest responses to regional and global environmental changes, and the reliability of these models depends on surface energy balance closure. However, for tidal ecosystems, the surface energy balance is complex because the energy transport associated with tidal activity remains poorly understood. This study aimed to quantify impacts of tidal flows on energy dynamics within a mangrove ecosystem. To address the research objective, an intensive 10-day study was conducted in a mangrove forest located along the Shark River in the Everglades National Park, FL, USA. Forest–atmosphere turbulent exchanges of energy were quantified with an eddy covariance system installed on a 30-m-tall flux tower. Energy transport associated with tidal activity was calculated based on a coupled mass and energy balance approach. The mass balance included tidal flows and accumulation of water on the forest floor. The energy balance included temporal changes in enthalpy, resulting from tidal flows and temperature changes in the water column. By serving as a net sink or a source of available energy, flood waters reduced the impact of high radiational loads on the mangrove forest. Also, the regression slope of available energy versus sink terms increased from 0.730 to 0.754 and from 0.798 to 0.857, including total enthalpy change in the water column in the surface energy balance for 30-min periods and daily daytime sums, respectively. Results indicated that tidal inundation provides an important mechanism for heat removal and that tidal exchange should be considered in surface energy budgets of coastal ecosystems. Results also demonstrated the importance of including tidal energy advection in mangrove biophysical models that are used for predicting ecosystem response to changing climate and regional freshwater management practices.