Do static sources outside a Schwarzschild black hole radiate?

We show that static sources coupled to a massless scalar field in Schwarzschild spacetime give rise to emission and absorption of zero-energy particles due to the presence of Hawking radiation. This is in complete analogy with the description of the bremsstrahlung by a uniformly accelerated charge from the coaccelerated observers' point of view. The response rate of the source is found to coincide with that in Minkowski spacetime as a function of its proper acceleration. It is interesting that this quantum result appears to reflect the classical equivalence principle.

Dynamics of energy transfer and frequency upconversion in Tm3+ doped fluoroindate glass

The spectroscopic properties of Tm3+-doped fluoroindate glasses (FIG) were described by single wavelength pumping in the red region. The Judd-Ofelt (J-O) theory was used to obtain the quantum efficiency of the 4f-4f transitions and other spectroscopic parameters. The dynamics of the fluorescence was investigated and energy transfer (ET) processes among Tm3+ ions were studied. The results indicate that a two-step one-photon absorption process is responsible for the ultraviolet upconversion (UC) emissions, and dipole-dipole interaction provides the main contribution for ET rate is equal to the decay rate of noninteracting among active ions.

Apparent absorption of zinc from supplemental inorganic and organic sources to Nile tilapia Oreochromis niloticus juveniles

Nile tilapia Oreochromis niloticus fingerlings were fed with purified or practical diets, supplemented with 150 Ing Zn/kg, from different sources. Dry matter (DM), crude protein (CP), ether extract (EE), and gross energy (GE) apparent digestibility coefficients (ADC), as well as zinc, copper, calcium, and phosphorus apparent absorption coefficients (AAC) were determined by the addition of 0.1% chromic oxide to the diets. The supplemental zinc sources utilized were commercial grade zinc sulfate monohydrate (ZnSO 4), zinc oxide (ZnO) and a zinc amino acid complex (Zn-AA). Analytical grade zinc sulfate heptahydrate was also utilized as a standard reference zinc source. There was a significant difference between purified (74.9%) and practical (41.3%) zinc AAC for the ZnO supplemented diets (P < 0.05). The supplemental zinc sources presented similar AAC when purified diets were utilized. However, ZnSO 4 was the best supplemental zinc source when practical type diets were used. There were no significant differences between supplemental zinc AAC from ZnS0 4 (68.9%), and supplemental zinc AAC from Zn-AA (61.3%) in practical diets, but Zn-AA diet showed a statistically lower zinc AAC when compared with the standard zinc source diet (75.6%). The practical diet supplemented with ZnO had the worst supplemental zinc AAC (41.3%). Dietary copper (74.21%), calcium (70.9%), and phosphorus (71.9%) AAC of the practical diets supplemented with ZnO were statistically lower (P < 0.05) than the respective AAC of the practical ZnSO 4 supplemented diets (83.6%, 84.1%, 87.1%).The ADC of the practical ZnO supplemented diet for DM (76.3%), CP (88.6%), EE (82.4%), and GE (81.6%) were statiscally lower than the respective ADC of the ZnSO 4 practical diet (86.0, 92.7, 93.6, 89.6%, respectively) and those ADC of the Zn-AA practical diet (84.7, 92.7, 93.7, 88.2%, respectively) (P < 0.05). Hence, these results indicate that ZnSO 4 and Zn-AA have equivalent intestinal absorption as supplemental zinc sources for Nile tilapia juveniles and both are superior to ZnO. © Copyright by the World Aquaculture Society 2005.

An assessment of the economic impact of climate change on the Agriculture, Energy and Health sectors in Trinidad and Tobago

This report analyses the agriculture, energy, and health sectors in Trinidad and Tobago to assess the potential economic impacts of climate change on the sectors. The fundamental aim of this report is to assist with the development of strategies to deal with the potential impact of climate change on Trinidad and Tobago. It also has the potential to provide essential input for identifying and preparing policies and strategies to help advance the Caribbean subregion closer to solving problems associated with climate change and attaining individual and regional sustainable development goals. Some of the key anticipated impacts of climate change for the Caribbean include elevated air and sea-surface temperatures, sea-level rise, possible changes in extreme events and a reduction in freshwater resources. The economic impact of climate change on the three sectors was estimated for the A2 and B2 IPCC scenarios until 2050. An exploration of various adaptation strategies was also undertaken for each sector using standard evaluation techniques. The study of the impact of climate change on the agriculture sector focused on root crops, green vegetables and fisheries. For these sectors combined, the cumulative loss under the A2 scenario is calculated as approximately B$2.24 and approximately B$1.72 under the B2 scenario by 2050. This is equivalent to 1.37% and 1.05% of the 2008 GDP under the A2 and B2 scenarios, respectively. Given the potential for significant damage to the agriculture sector a large number of potential adaptation measures were considered. Out of these a short-list of 10 potential options were selected by applying 10 evaluation criteria. All of the adaptation strategies showed positive benefits. The analysis indicate that the options with the highest net benefits are: (1) Building on-farm water storage, (2) Mainstreaming climate change issues into agricultural management and (3) Using drip irrigation. Other attractive options include water harvesting. The policy decisions by governments should include these assessments, the omitted intangible benefits, as well as the provision of other social goals such as employment. The analysis of the energy sector has shown that the economic impact of climate change during 2011-2050 is similar under the A2 (US$142.88 million) and B2 (US$134.83 million) scenarios with A2 scenario having a slightly higher cost (0.737% of 2009 GDP) than the B2 scenario (0.695% of 2009 GDP) for the period. On the supply side, analyses indicate that Trinidad and Tobago’s energy sector will be susceptible to the climate change policies of major energy-importing countries (the United States of America and China), and especially to their renewable energy strategies. Implementation of foreign oil substitution policy by the United States of America will result in a decline in Trinidad and Tobago’s Liquefied Natural Gas (LNG) export (equivalent to 2.2% reduction in 2009 GDP) unless an alternative market is secured for the lost United States of America market. China, with its rapid economic growth and the highest population in the world, offers a potential replacement market for Trinidad and Tobago’s LNG export. In this context the A2 scenario will offer the best option for Trinidad and Tobago’s energy sector. The cost-benefit analysis undertaken on selected adaptation strategies reveal that the benefit-cost ratio of replacing electric water heaters with solar water heaters is the most cost-effective. It was also found that the introduction of Compact Fluorescent Light (CFL) and Variable Refrigerant Volume (VRV) air conditioners surpasses the projected cost of increased electricity consumption due to climate change, and provides an economic rationale for the adoption of these adaptation options even in a situation of increased electricity consumption occasioned by climate change. Finally, the conversion of motor fleets to Compressed Natural Gas (CNG) is a cost-effective adaptation option for the transport sector, although it has a high initial cost of implementation and the highest per capita among the four adaptation options evaluated. To investigate the effect of climate change on the health sector dengue fever, leptospirosis, food borne illnesses, and gastroenteritis were examined. The total number of new dengue cases for the period 2008 to 2050 was 204,786 for BAU, 153,725 for A2 and 131,890 for the B2 scenario. With regard to the results for leptospirosis, A2 and B2 seem to be following a similar path with total number of new cases in the A2 scenario being 9,727 and 9,218 cases under the B2 scenario. Although incidence levels in the BAU scenario coincided with those of A2 and B2 prior to 2020, they are somewhat lower post 2020. A similar picture emerges for the scenarios as they relate to food-borne illnesses and to gastroenteritis. Specifically for food-borne illnesses, the BAU scenario recorded 27,537 cases, the A2 recorded 28,568 cases and the B2 recorded 28,679 cases. The focus on the selected sources of morbidity in the health sector has highlighted the fact that the vulnerability of the country’s health sector to climate change does not depend solely on exogenously derived impacts, but also on the behaviour and practices among the population. It is clear that the vulnerability which became evident in the analysis of the impacts on dengue fever, leptospirosis and food-borne illnesses is not restricted solely to climate or other external factors. The most important adaptation strategy being recommended targets lifestyle, behaviour and attitude changes. The population needs to be encouraged to alter their behaviours and practices so as to minimise their exposure to harmful outcomes as it relates to the incidence of these diseases.

A study on energy issues in the Caribbean: potential for mitigating climate change

The United Nations Economic Commission for Latin America and the Caribbean (ECLAC) is seeking to provide support to the Governments of Guyana, Jamaica and Barbados in researching the potential for employing renewable energy technologies to mitigate climate change. This exercise involves the study of different types of renewable technologies and mitigative strategies, with the aim of making recommendations to the governments on the development of their renewable energy sector. The recommendations may also assist in achieving their long-term objectives of reducing poverty and promoting healthy economies and sustainable livelihoods in keeping with the Millennium Development Goals. Guyana, Jamaica and Barbados each face common and specific challenges in their efforts to adequately define and implement their energy and climate policies, in a way that allows them to contribute to the mitigation effort against climate change, while promoting sustainable development within their countries. Each country has demonstrated an understanding of the global and national challenges pertaining to climate change. They have attempted to address these challenges through policies and various programmes implemented by local and international agencies. Documented and undocumented policies have sought to outline the directions to be taken by each territory as they seek to deploy new technologies to address issues related to energy and the environment. While all territories have sought to deploy multiple alternate and renewable technologies simultaneously, it is clear that, given their sizes and resource limitations, no one territory can achieve excellence in all these areas. Guyana has demonstrated the greatest potential for hydro energy and should pursue it as their main area of expertise. The country also has an additional major strategy that includes forest credits and the Reduced Emissions from Deforestation and Degradation (REDD) programme. This approach will be brought to the negotiation table in the upcoming climate change meeting in Copenhagen in December 2009. Of the three countries, Jamaica has the only active significant wind farm deployment, while Barbados has a long tradition in solar energy. Each country might then supplement their energy and fuel mix with other energy and fuel sources and draw from the experience of other countries. Given the synergies that might accrue from adopting a regional approach, the Caribbean Community Climate Change Centre (CCCCC) might be well positioned to play a coordinating role. This focus on renewable energy and biofuels should yield good, long-term results as it relates to mitigation against climate change, and good, short- and medium-term results as it relates to the development of sustainable economies. Each country might also achieve energy security, reduced oil dependence, significant reduction in harmful emissions and better foreign exchange management if they pursue good policies and implementation practices. Human and financial resources are critical to the success of planned interventions, and it will be necessary to successfully mobilize these resources in order to be effective in executing key plans.

Effect of lipid sources and inclusion levels in diets for broiler chickens

This research aimed to evaluate the interactions and effects of 2 and 4% addition levels of poultry slaughterhouse fat (chicken tallow) and soybean oil in diets for broiler chickens. Two experiments were carried out using one-day-old male Cobb chicks in an entirely random design with a 2x2 factorial scheme. In the first experiment, 560 chicks were used to evaluate performance and carcass characteristics. In the second experiment, 100 chicks were used to determine the nutrient digestibility, dietary energy utilization and the lipase and amylase pancreatic activity. There was no interaction between the fat sources and the addition levels for any of the analyzed variables, except for the digestibility coefficient of dry matter (DCDM), which was higher in diets added with 2% soybean oil when compared to chicken tallow. The addition of 4% fat in the diet, regardless of fat source, improved the digestibility coefficient of ethereal extract (DCEE) and increased weight gain and feed intake. Moreover, in the initial phase, the addition of 4% fat to the diet increased lipase activity when compared to diets with 2% addition, and a positive correlation between DCEE and pancreatic lipase activity was observed. In conclusion, there is no interaction between fat sources and addition levels, except for DCDM. Carcass characteristics are not influenced by any of the studied factors. The addition of 4% fat increases pancreatic lipase activity and improves DCEE, resulting in greater weight gain, regardless of the tested fat source, making chicken tallow a great alternative to soybean oil.

Effect of lipid sources with different fatty acid profiles on the intake, performance, and methane emissions of feedlot Nellore steers

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Brewer's yeast and sugarcane yeast as protein sources for dogs

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)