A multi-dimensional spectral description of ocean variability with applications

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 2013Efforts to monitor the ocean for signs of climate change are hampered by ever-present noise, in the form of stochastic ocean variability, and detailed knowledge of the character of this noise is necessary for estimating the significance of apparent trends. Typically, uncertainty estimates are made by a variety of ad hoc methods, often based on numerical model results or the variability of the data set being analyzed. We provide a systematic approach based on the four-dimensional frequency-wavenumber spectrum of low-frequency ocean variability. This thesis presents an empirical model of the spectrum of ocean variability for periods between about 20 days and 15 years and wavelengths of about 200{10,000 km, and describes applications to ocean circulation trend detection, observing system design, and satellite data processing. The horizontal wavenumber-frequency part of the model spectrum is based on satellite altimetry, current meter data, moored temperature records, and shipboard ADCP data. The spectrum is dominated by motions along a "nondispersive line". The observations considered are consistent with a universal ω-2 power law at the high end of the frequency range, but inconsistent with a universal wavenumber power law. The model spectrum is globally varying and accounts for changes in dominant phase speed, period, and wavelength with location. The vertical structure of the model spectrum is based on numerical model results, current meter data, and theoretical considerations. We find that the vertical structure of kinetic energy is surface intensified relative to the simplest theoretical predictions. We present a theory for the interaction of linear Rossby waves with rough topography; rough topography can explain both the observed phase speeds and vertical structure of variability. The improved description of low-frequency ocean variability presented here will serve as a useful tool for future oceanographic studies.This research was supported by NASA under grants NNG06GC28G and NNX08AR33G

X-ray microanalysis in STEM of short-term physico-chemical reactions at bioactive glass particles / biological fluids interface. Determination of O/Si atomic ratios

Short-term physico-chemical reactions at the interface between bioactive glass particles and biological fluids are studied and we focus our attention on the measurements of O/Si atomic ratio. The studied bioactive glass is in the SiO2-Na2O-CaO-P2O5-K2O-Al2O3-MgO system. The elemental analysis is performed at the submicrometer scale by STEM associated with EDXS and EELS. We previously developed an EDXS quantification method based on the ratio method and taking into account local absorption corrections. In this way, we use EELS data to determine, by an iterative process, the local mass thickness which is an essential parameter to correct absorption in EDXS spectra. After different delays of immersion of bioactive glass particles in a simulated biological solution, results show the formation of different surface layers at the bioactive glass periphery. Before one day of immersion, we observe the presence of an already shown (Si,O,Al) rich layer at the periphery. In this paper, we demonstrate that a thin electron dense (Si,O) layer is formed on top of the (Si,O,Al) layer. In this (Si,O) layer, depleted in aluminium, we point out an increase of oxygen weight concentration which can be interpreted by the presence of Si(OH)4 groups, that permit the formation of a (Ca,P) layer. Aluminium plays a role in the glass solubility and may inhibit apatite nucleation. After the beginning of the (Ca,P) layer formation, the size of the electron dense (Si,O) layer decreases and tends to disappear. After two days of immersion, the (Ca,P) layer grows in thickness and leads to apatite precipitatio

Using ACEI\u27s Global Guidelines Assessment for Improving Early Education

The Global Guidelines for Early Childhood Education and Care in the 21st Century were developed as a collaborative project between the U. S. National Committee of the World Organization for Early Childhood (OMEP) and of the Association for Childhood Education International (ACEI). The project’s intent was to provide guidance concerning the fundamental elements that are necessary to create high quality environments for early care and education. This paper presents the history of the development of a related instrument, called the ACEI Global Guidelines Assessment (GGA). The GGA was developed to help early childhood educators assess and improve program quality, particularly in developing countries. It is divided into five areas: (1) Environment and Physical Space; (2) Curriculum Content and Pedagogy; (3) Early Childhood Educators and Caregivers; (4) Partnership with Families and Communities; and (5) Young Children with Special Needs. The GGA was designed to serve several purposes: (1) to provide a research-based process for making statements to distribute to national government leaders; (2) to promote and provoke policy discussions and curriculum development; and (3) to guide early childhood educators throughout the world to assess their own programs for children

Using ACEI\u27s Global Guidelines Assessment for Improving Early Education

The Global Guidelines for Early Childhood Education and Care in the 21st Century were developed as a collaborative project between the U. S. National Committee of the World Organization for Early Childhood (OMEP) and of the Association for Childhood Education International (ACEI). The project’s intent was to provide guidance concerning the fundamental elements that are necessary to create high quality environments for early care and education. This paper presents the history of the development of a related instrument, called the ACEI Global Guidelines Assessment (GGA). The GGA was developed to help early childhood educators assess and improve program quality, particularly in developing countries. It is divided into five areas: (1) Environment and Physical Space; (2) Curriculum Content and Pedagogy; (3) Early Childhood Educators and Caregivers; (4) Partnership with Families and Communities; and (5) Young Children with Special Needs. The GGA was designed to serve several purposes: (1) to provide a research-based process for making statements to distribute to national government leaders; (2) to promote and provoke policy discussions and curriculum development; and (3) to guide early childhood educators throughout the world to assess their own programs for children

Education and Policy in the New Latin Diaspora

Increasing numbers of Latinos (many immigrant, and some from elsewhere in the US) are settling both temporarily and permanently in areas of the US that have not traditionally been home to Latinos—e.g., North Carolina, Maine, Georgia, Indiana, Arkansas, rural Illinois and near resort communities in Colorado. Enrique Murillo and Sofia Villenas have called this the New Latino Diaspora (Murillo and Villenas, 1995). Newcomer Latinos are confronted with novel challenges to their senses of identity, status, and community. Instead of arriving in settings, like the Southwest, where Latinos have lived for centuries, those in the New Latino Diaspora arrive in unfamiliar places where long-term residents have little experience with Latinos. In the New Diaspora, then, Latinos face more insistent questions about who they are, who they seek to be, and what accommodations they merit - questions that are asked both by themselves and by others

Eddy stirring and horizontal diffusivity from Argo float observations : geographic and depth variability

Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 42 (2015): 3989–3997, doi:10.1002/2015GL063827.Stirring along isopycnals is a significant factor in determining the distribution of tracers within the ocean. Salinity anomalies on density surfaces from Argo float profiles are used to investigate horizontal stirring and estimate eddy mixing lengths. Eddy mixing length and velocity fluctuations from the ECCO2 global state estimate are used to estimate horizontal diffusivity at a 300 km scale in the upper 2000 m with near-global coverage. Diffusivity varies by over two orders of magnitude with latitude, longitude, and depth. In all basins, diffusivity is elevated in zonal bands corresponding to strong current regions, including western boundary current extension regions, the Antarctic Circumpolar Current, and equatorial current systems. The estimated mixing lengths and diffusivities provide an observationally based data set that can be used to test and constrain predictions and parameterizations of eddy stirring.This work was supported by the National Science Foundation under grants OCE-13-55668 and OCE-95-21468 and the Office of Naval Research under grants N00014-12-1-0336 and N00014-13-1-0484.2015-11-2

Communication

From a traditional engineering perspective, communication is about effecting control over a distance, and its primary concern is the reliability of transmission. This chapter reviews communication in nature, describing its evolution from the perspective of the selfish gene. Communication in nature is ubiquitous and generally honest, and arises as much from collaboration as manipulation. We show that context and relevance allow effective communication with little information transfer, particularly between organisms with similar capacities and goals. Human language differs fundamentally from the non-verbal communication we share with other animals; robots may need to accommodate both. We document progress in AI capacities to generate synthetic emotion and to sense and classify human emotion. Communication in contemporary biomimetic systems is between robots in swarm robotics, but also between robot and human for both autonomous and collaborative systems. We suggest increased future emphasis on capacities to receive and comprehend signs, and on the pragmatic utility of communication and cooperation.</p

Using the ACEI\u27s Global Guidelines Assessment for Improving Early Education

The Global Guidelines for Early Childhood Education and Care in the 21st Century were developed as a collaborative project between the U. S. National Committee of the World Organization for Early Childhood (OMEP) and of the Association for Childhood Education International (ACEI). The project\u27s intent was to provide guidance concerning the fundamental elements that are necessary to create high quality environments for early care and education. This paper presents the history of the development of a related instrument, called the ACEI Global Guidelines Assessment (GGA). The GGA was developed to help early childhood educators assess and improve program quality, particularly in developing countries. It is divided into five areas: (1) Environment and Physical Space; (2) Curriculum Content and Pedagogy; (3) Early Childhood Educators and Caregivers; (4) Partnership with Families and Communities; and (5) Young Children with Special Needs. The GGA was designed to serve several purposes: (1) to provide a research-based process for making statements to distribute to national government leaders; (2) to promote and provoke policy discussions and curriculum development; and (3) to guide early childhood educators throughout the world to assess their own programs for children