Effects of Geometry on Sound Radiation from Three-Dimensional Rectangular Structures

Mechanical Engineerin

Information and Communication Technology Use by Agriscience Teachers in Trinidad and Tobago

The purpose of this study was to investigate information and communication technologies (ICT) usage among Agriscience teachers in Trinidad and Tobago. This knowledge will be used to develop preservice and inservice professional development programming for these teachers. Eighty-five percent (n = 77) of the secondary Agriscience teachers responded to a survey that assessed: (a) technology current use, (b) technology beliefs, (c) technology skills, (d) technology intentions, (e) barriers to technology use, and (f) personal data. Results indicated that Agriscience teachers in Trinidad have accepted ICT as useful tools. Teachers used ICT most frequently for personal reasons and less frequently for school-related tasks. Teachers generally believed that ICT help them accomplish tasks more quickly, enhance their quality of work, were easy to use, and that it could help to keep in touch with their students. However, beliefs varied based on age, career intentions, and computer literacy. Agriscience teachers also indicated that they possessed moderate skill levels and intend to use ICT as a part of their jobs. Differences in perceived skills were noted based on age, experience, and career intentions. Primary barriers centered on technical issues such as lack of hardware, inadequate technical infrastructure, and connectivity. Additionally, teachers believed that lack of a reward structure impeded technology usage

Trinidad Food Producers’ Training Needs for Food Security and Implications for Extension

The purpose of this study was to explore farmers’ knowledge of food security issues in Trinidad. Such information can be used to develop appropriate extension training interventions. Using a Borich (1980) methodology, a total of 300 agricultural producers in Trinidad were surveyed with an instrument that consisted of two parts: (a) personal demographic and farm related questions, and (b) indicators of knowledge and importance of 27 food security issues derived from The National Food Production Action Plan 2012 – 2015. Overall, the top five issues identified by producers were: (a) the incentive program that is focused on outputs; (b) research and development for both livestock and crop farmers; (c) partnerships between public sector agencies, research institutions, and the private sector to provide suitable capacity to deliver all food production programs; (d) postharvest technologies that create employment opportunities, increase returns to farmers, improve food quality, and ensure food safety; and (e) and technology packages (of information) to help farmers improve yield, quality, and availability. All 27 food security issues varied in at least one of the categories assessed: 22 issues varied by location; 18 issues varied by farm type; 5 issues varied by farming status; and 19 issues varied by education level of the farmer. These results can guide extension programming in Trinidad and also be informative for policy makers

Effects of Aging and Adult-Onset Hearing Loss on Cortical Auditory Regions

Hearing loss is a common feature in human aging. It has been argued that dysfunctions in central processing are important contributing factors to hearing loss during older age. Aging also has well documented consequences for neural structure and function, but it is not clear how these effects interact with those that arise as a consequence of hearing loss. This paper reviews the effects of aging and adult-onset hearing loss in the structure and function of cortical auditory regions. The evidence reviewed suggests that aging and hearing loss result in atrophy of cortical auditory regions and stronger engagement of networks involved in the detection of salient events, adaptive control and re-allocation of attention. These cortical mechanisms are engaged during listening in effortful conditions in normal hearing individuals. Therefore, as a consequence of aging and hearing loss, all listening becomes effortful and cognitive load is constantly high, reducing the amount of available cognitive resources. This constant effortful listening and reduced cognitive spare capacity could be what accelerates cognitive decline in older adults with hearing loss

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Fusion transmutation of waste: design and analysis of the in-zinerator concept.

Due to increasing concerns over the buildup of long-lived transuranic isotopes in spent nuclear fuel waste, attention has been given in recent years to technologies that can burn up these species. The separation and transmutation of transuranics is part of a solution to decreasing the volume and heat load of nuclear waste significantly to increase the repository capacity. A fusion neutron source can be used for transmutation as an alternative to fast reactor systems. Sandia National Laboratories is investigating the use of a Z-Pinch fusion driver for this application. This report summarizes the initial design and engineering issues of this ''In-Zinerator'' concept. Relatively modest fusion requirements on the order of 20 MW can be used to drive a sub-critical, actinide-bearing, fluid blanket. The fluid fuel eliminates the need for expensive fuel fabrication and allows for continuous refueling and removal of fission products. This reactor has the capability of burning up 1,280 kg of actinides per year while at the same time producing 3,000 MWth. The report discusses the baseline design, engineering issues, modeling results, safety issues, and fuel cycle impact