Investigating Long-Term Diet and Marine Resource Use in Kohala, Hawaiʻi

Social and Behavioral Sciences: 3rd Place (The Ohio State University Denman Undergraduate Research Forum)Marine animals, including fish, mollusk, octopus and squid, were key components of the Hawaiian diet in prehistory. The goal of my research project is to examine long-term prehistoric gathering strategies and to determine if resource depression of mollusk populations in prehistory. I am currently investigating mollusk use in prehistory by analyzing remains from archaeological household sites in Kohala, Hawaiʻi. I am looking at the distribution of different species of mollusk remains throughout Kohala, and analyzing the changes through time. This project is ongoing, but so far I have found no significant changes in species consumed that indicate resource depression. The species and amount of mollusk consumed through time varies within regions in Kohala, but does not indicate a negative human impact on marine resources through time.Academic Major: Anthropological Science

Optical frequency synthesis and measurement using fibre-based femtosecond lasers

We report the synthesis and measurement of an ultra-precise and extremely stable optical frequency in the telecommunications window around 1543 nm. Using a fibre-based femtosecond frequency comb we have phase-stabilised a fibre laser at 194 THz to an optical frequency standard at 344 THz, thus transferring the properties of the optical frequency standard to another spectral region. Relative to the optical frequency standard, the synthesised frequency at 194 THz is determined to within 1 mHz and its fractional frequency instability is measured to be less than 2*10^{-15} at 1 s, reaching 5*10^{-18} after 8000 s. We also measured the synthesised frequency against a caesium fountain clock: here the frequency comparison itself contributes less than 4 mHz (2*10^{-17}) to the uncertainty. Our results confirm the suitability of fibre based frequency comb technology for precision measurements and frequency synthesis, and enable long-distance comparison of optical clocks by using optical fibres to transmit the frequency information

EHLSSA: Europe-Wide Online Learning for Seniors

La tecnología domina el futuro, y cada vez en mayor medida penetra en la cultura y en la sociedad. En el curso de esta tendencia, el aprendizaje en línea está adquiriendo importancia y se está convirtiendo en un componente fundamental e integral del aprendizaje permanente. Sin embargo, el grupo de ciudadanos de la tercera edad es uno de los principales que quedan excluidos del uso de las nuevas tecnologías, aunque los dispositivos digitales proporcionan a cada ciudadano nuevas oportunidades y perspectivas. El proyecto EHLSSA –siglas de European Home Learning Service for Seniors Association, Asociación de Servicios Europeos para el Aprendizaje de las Personas Mayores desde el Hogar– toma este hallazgo como punto de partida y desarrolla soluciones de aprendizaje en línea para la tercera edad en toda Europa. El presente artículo presenta la importancia y el valor añadido de modelos de aprendizaje en línea específicamente adaptados a este grupo tan heterogéneo.Technology dominates the future and it is increasingly penetrating culture and society. In the course of this trend, online learning is gaining importance and becoming a crucial and integral component of lifelong learning. Still, the group of senior citizens is one of the groups that are predominantly excluded from using new technologies, though digital devices provide each citizen with new opportunities and perspectives. The EHLSSA project– European Home Learning Service for Seniors Association – takes this finding as its starting point and develops e-learning solutions for seniors around Europe. The importance and added-value of specially adapted e-learning models for this highly heterogeneous group is presented in this article

Frequency comparisons and absolute frequency measurements of 171Yb+ single-ion optical frequency standards

We describe experiments with an optical frequency standard based on a laser cooled $^{171}$Yb$^+$ ion confined in a radiofrequency Paul trap. The electric-quadrupole transition from the $^2S_{1/2}(F=0)$ ground state to the $^2D_{3/2}(F=2)$ state at the wavelength of 436 nm is used as the reference transition. In order to compare two $^{171}$Yb$^+$ standards, separate frequency servo systems are employed to stabilize two probe laser frequencies to the reference transition line centers of two independently stored ions. The experimental results indicate a relative instability (Allan standard deviation) of the optical frequency difference between the two systems of $\sigma_y(1000 {\rm s})=5\cdot 10^{-16}$ only, so that shifts in the sub-hertz range can be resolved. Shifts of several hertz are observed if a stationary electric field gradient is superimposed on the radiofrequency trap field. The absolute optical transition frequency of Yb$^+$ at 688 THz was measured with a cesium atomic clock at two times separated by 2.8 years. A temporal variation of this frequency can be excluded within a $1\sigma$ relative uncertainty of $4.4\cdot 10^{-15}$ yr$^{-1}$. Combined with recently published values for the constancy of other transition frequencies this measurement provides a limit on the present variability of the fine structure constant $\alpha$ at the level of $2.0\cdot 10^{-15}$ yr$^{-1}$.Comment: 12 pages, 5 figures, Proceedings of MPLP'04, Novosibirsk, August 22.-27., 200