Explorando algunas trayectorias recientes de la justicia en la geografía humana contemporánea: de la justicia territorial a las justicias espaciales

a justicia empezó a ser valorada como categoría de análisis en geografía a partir del surgimiento de la crítica radical en los años setenta del siglo pasado. Desde entonces han surgido diferentes enfoques respecto a la justicia, por lo que el objetivo central en este escrito es discutir que proponen dichas tendencias y concluir sobre los debates por venir en el tema durante los próximos años. En la primera parte se discutirá el concepto de justicia territorial, para luego explorar la discusión neomarxista contemporánea sobre la justicia en geografía humana, además de lo que ha sido propuesto desde otros enfoques, tales como el de la geografía del bienestar, la geografía cuantitativa y, finalmente, la teoría de la justicia espacial de Edward Soja

Generation of intense isolated attosecond pulses at 100 eV

Originally limited to big facilities, nonlinear optics experiments in the extreme ultraviolet (XUV) spectral region with table-top systems are becoming a reality. These fundamentally different sources arise from a process known as high-harmonic generation (HHG). In this process, intense mid-IR to UV radiation is converted into the XUV to soft x-rays spectral region when interacting with a gas medium. The broad bandwidth supported by this process additionally allows the isolation of pulses with durations in the attosecond regime. However, given the low conversion efficiency of the HHG process, reaching the necessary XUV intensities to probe nonlinear effects has proven to be a challenging task. The initial investigations in this direction have been realized with photon energies up to 50 eV, by successfully scaling the XUV pulse energy through the use of multi-terawatt driving lasers. In this thesis, the generation and application of intense attosecond XUV-pulses in the 100 eV spectral region is presented. The XUV pulse energy increase is fundamentally enabled thanks to the development of a 16 TW optical-parametric synthesizer based on a two-color pumping technique, which provides pulse durations below two optical cycles. The achieved pulse energy, short pulse duration and the possibility to independently measure the carrier-envelope phase (CEP), makes this laser system a suitable driver of an XUV attosecond source. Through a careful energy scaling scheme, pulse energies above 20 nJ are routinely achieved in a spectrum spanning from 70 to 130 eV. A continuous spectral region is observed in single-shot between 100-130 eV for the appropriate CEP. This allows the isolation of attosecond pulses through spectral filtering. In addition to these high energies and broadband spectra, the reproducibility and long-term stability of the XUV beam makes it suitable for its use towards applications. As a proof-of-principle experiment, the XUV beam is focused to a measured beam size smaller than 3.1 micrometers,where the intensity is estimated to be above 10e13 W/cm2. At focus, the generation of Xe4+ and Xe5+ ions through the absorption of two photons is demonstrated. This is the first realization of such a measurement at these photon energies with a HHG source, paving the way to future attosecond time-resolved nonlinear spectroscopy of inner-shell electron dynamics

Dolomitization of the Devonian Wabamun carbonates in the Gold Creek Field west central Alberta, Canada.

In the Peace River Arch (PRA), the Wabamun Group is commonly dolomitized where it overlies Leduc or Nisku patch reefs, grading from limestone to dolostone over relatively short distances. This suggests that fluid-flow accessed the porous carbonate buildups favored dolomitization in the overlying Wabamun. Differential compaction between the rigid reef framework and the surrounding shales (Ireton Formation) during Late Devonian to Early Mississippian is thought to be the trigger for the development of fault and fracture systems that ultimately allowed diagenetic fluids which favored the dolomitization of the Wabamun carbonates. The present study is focused on understanding the dolomitization process in the Gold Creek Field, its relationship with the porosity evolution of the area, and the geochemical characterization of the fluids responsible for such dolomitization. Petrophysical attributes of the Wabamun carbonates were studied with the aid of an innovative Image Analysis technique. Interesting correlations between hydrothermal fluid-flow and porosity evolution were observed in the Wabamun at Gold Creek Field. (Abstract shortened by UMI.)Dept. of Earth Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2004 .R58. Source: Masters Abstracts International, Volume: 43-05, page: 1680. Adviser: Ihsan Al-Aasm. Thesis (M.Sc.)--University of Windsor (Canada), 2004

A new stylolite classification scheme to estimate compaction and local permeability variations

This study was carried out within the framework of DGMK (German Society for Petroleum and Coal Science and Technology) research project 718 “Mineral Vein Dynamics Modeling”, which is funded by the companies ExxonMobil Production Deutschland GmbH, GDF SUEZ E&P Deutschland GmbH, DEA Deutsche Erdoel AG and Wintershall Holding GmbH, within the basic research program of the WEG Wirtschaftsverband Erdoel- und Erdgasgewinnung e.V. We thank the companies for their financial support and their permission to publish these results. This work has received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no 31688. The Zechstein data were collected with the help of Simon Gast. We thank Jean-Pierre Gratier and an anonymous reviewer for their comments that improved an earlier version of the manuscript.Peer reviewedPostprin

Inhibition of Protein Farnesylation Arrests Adipogenesis and Affects PPARγ Expression and Activation in Differentiating Mesenchymal Stem Cells

Protein farnesylation is required for the activation of multiple proteins involved in cell differentiation and function. In white adipose tissue protein, farnesylation has shown to be essential for the successful differentiation of preadipocytes into adipocytes. We hypothesize that protein farnesylation is required for PPARγ2 expression and activation, and therefore for the differentiation of human mesenchymal stem cells (MSCs) into adipocytes. MSCs were plated and induced to differentiate into adipocytes for three weeks. Differentiating cells were treated with either an inhibitor of farnesylation (FTI-277) or vehicle alone. The effect of inhibition of farnesylation in differentiating adipocytes was determined by oil red O staining. Cell survival was quantified using MTS Formazan. Additionally, nuclear extracts were obtained and prelamin A, chaperon protein HDJ-2, PPARγ, and SREBP-1 were determined by western blot. Finally, DNA binding PPARγ activity was determined using an ELISA-based PPARγ activation quantification method. Treatment with an inhibitor of farnesylation (FTI-277) arrests adipogenesis without affecting cell survival. This effect was concomitant with lower levels of PPARγ expression and activity. Finally, accumulation of prelamin A induced an increased proportion of mature SREBP-1 which is known to affect PPARγ activity. In summary, inhibition of protein farnesylation arrests the adipogenic differentiation of MSCs and affects PPARγ expression and activity

Marine Corps Tactical Satellite Communications

A tactical satellite communications exercise using the DARPA Microsats was conducted by Naval Academy personnel at the Quantico Marine Corps Base in Virginia. Midshipmen used a military UHF radio, a modified amateur radio transmitter, and scanner receivers while a station in Annapolis communicated with them. Voice communications were clear and understandable even when the tactical teams were in the woods. Amateur radio operators and scanner enthusiasts around the eastern half of the United States and Canada successfully monitored the Microsat downlinks during the demonstration

Resilient Design in The Tropics: An Overheating Assessment Method for Naturally Ventilated Buildings

As a consequence of global warming, overheating has become the main source of discomfort when speaking about the thermal performance of buildings. On the one hand, energy consumption together with the risk of heatstroke rises during warm periods and in extreme situations such as heatwaves. On the other hand, there is no broadly accepted method to measure overheating. Most of the literature is limited to a simple count of hours above comfort limit, disregarding the intensity and temporal extent of the periods, whereas other methods have a limited application since they were developed for a certain type of building and location. This paper proposes a novel method for overheating assessment in existing and projected buildings based on 5-step criteria. The objective of the process is to assess the intensity and the total time extent of overheating following adaptive theory and established limits of human comfort. The method consists in hourly counts of overheating hours divided into five segments (i.e. hours above 0.1°K, 1°K, 2°K, 3°K, and 4°K) using the upper comfort limit as a threshold. The output of the method thus provides a quantitative answer regarding overheating in a building, assessing not only the intensity but the range of the problem, allowing to evaluate different strategies to regain comfortable conditions for the occupants