Chaco Canyon: A Contested Memory Anchor in the North American Southwest

Natural and archaeological places are powerful loci for social memories and continually negotiated meanings. As ‘memory anchors’ they are focal points for the construction of memory and meaning, and can become flashpoints for disputes over access, land-use, and knowledge claims among stakeholders with contradictory interests. In the North American Southwest the competing claims of Native American tribes, archaeologists, government bureaucrats, tourists, and the mining industry come into sharp relief. In this paper, I explore how the UNESCO World Heritage Site of Chaco Canyon figures prominently in the origin stories and sacred geographies of contemporary Pueblo and Navajo peoples – two indigenous groups with competing political stakes in the present

Returning home: heritage work among the Stl'atl'imx of the Lower Lillooet River Valley

This article focusses on heritage practices in the tensioned landscape of the Stl’atl’imx (pronounced Stat-lee-um) people of the Lower Lillooet River Valley, British Columbia, Canada. Displaced from their traditional territories and cultural traditions through the colonial encounter, they are enacting, challenging and remaking their heritage as part of their long term goal to reclaim their land and return ‘home’. I draw on three examples of their heritage work: graveyard cleaning, the shifting ‘official’/‘unofficial’ heritage of a wagon road, and marshalling of the mountain named Nsvq’ts (pronounced In-SHUCK-ch) in order to illustrate how the past is strategically mobilised in order to substantiate positions in the present. While this paper focusses on heritage in an Indigenous and postcolonial context, I contend that the dynamics of heritage practices outlined here are applicable to all heritage practices

Frequency drift in MR spectroscopy at 3T

Purpose: Heating of gradient coils and passive shim components is a common cause of instability in the B-0 field, especially when gradient intensive sequences are used. The aim of the study was to set a benchmark for typical drift encountered during MR spectroscopy (MRS) to assess the need for real-time field-frequency locking on MRI scanners by comparing field drift data from a large number of sites.Method: A standardized protocol was developed for 80 participating sites using 99 3T MR scanners from 3 major vendors. Phantom water signals were acquired before and after an EPI sequence. The protocol consisted of: minimal preparatory imaging; a short pre-fMRI PRESS; a ten-minute fMRI acquisition; and a long post-fMRI PRESS acquisition. Both pre- and post-fMRI PRESS were non-water suppressed. Real-time frequency stabilization/adjustment was switched off when appropriate. Sixty scanners repeated the protocol for a second dataset. In addition, a three-hour post-fMRI MRS acquisition was performed at one site to observe change of gradient temperature and drift rate. Spectral analysis was performed using MATLAB. Frequency drift in pre-fMRI PRESS data were compared with the first 5:20 minutes and the full 30:00 minutes of data after fMRI. Median (interquartile range) drifts were measured and showed in violin plot. Paired t-tests were performed to compare frequency drift pre- and post-fMRI. A simulated in vivo spectrum was generated using FID-A to visualize the effect of the observed frequency drifts. The simulated spectrum was convolved with the frequency trace for the most extreme cases. Impacts of frequency drifts on NAA and GABA were also simulated as a function of linear drift. Data from the repeated protocol were compared with the corresponding first dataset using Pearson's and intraclass correlation coefficients (ICC).Results: Of the data collected from 99 scanners, 4 were excluded due to various reasons. Thus, data from 95 scanners were ultimately analyzed. For the first 5:20 min (64 transients), median (interquartile range) drift was 0.44 (1.29) Hz before fMRI and 0.83 (1.29) Hz after. This increased to 3.15 (4.02) Hz for the full 30 min (360 transients) run. Average drift rates were 0.29 Hz/min before fMRI and 0.43 Hz/min after. Paired t-tests indicated that drift increased after fMRI, as expected (p &lt; 0.05). Simulated spectra convolved with the frequency drift showed that the intensity of the NAA singlet was reduced by up to 26%, 44 % and 18% for GE, Philips and Siemens scanners after fMRI, respectively. ICCs indicated good agreement between datasets acquired on separate days. The single site long acquisition showed drift rate was reduced to 0.03 Hz/min approximately three hours after fMRI.Discussion: This study analyzed frequency drift data from 95 3T MRI scanners. Median levels of drift were relatively low (5-min average under 1 Hz), but the most extreme cases suffered from higher levels of drift. The extent of drift varied across scanners which both linear and nonlinear drifts were observed.</p

El Cañón del Chaco: un disputado anclaje de memoria en el sudoeste de Norteamérica

Los relatos, historias y tradiciones orales crean conexiones emocionales, vinculando a la gente con lugares. Tanto los lugares naturales como los arqueológicos son loci poderosos para la memoria social y los significados sociales, constituyendo “anclajes de memoria” intramundanos que se transforman en puntos focales para la construcción de memoria y significado a través del tiempo. En el Sudoeste de Norteamérica (región que comprende el sudoeste del estado de Colorado, sudeste del estado de Utah y los estados de Nuevo México y Arizona, en los Estados Unidos; noroeste de Chihuahua y norte de Sonora, en México), los anclajes de memorias tales como el Cañón del Chaco, declarado Patrimonio Mundial por la UNESCO, constituyen lugares emocionalmente cargados que figuran prominentemente en los relatos de origen y en las geografías sagradas de los grupos Navajo y Pueblo, pueblos indígenas que en la actualidad tienen agendas políticas distintas y en competencia en relación con el acceso a estos lugares, así como al uso de la tierra y la construcción de conocimiento. En este trabajo, se considera al Cañón del Chaco como un anclaje de memoria disputado, que es reclamado por diversas facciones indígenas y euroamericanas con intereses contrapuestos.Stories, histories, and oral traditions create emotional connections, attaching peoples to places. Both natural and archaeological places are powerful loci for social memories and meanings that are continually constructed, obliterated, altered, and reconstructed. These intra-worldly “memory anchors” become focal points for the construction of memory and meaning over time. In the North American Southwest (southwest Colorado, southeast Utah, New Mexico, Arizona, northwest Chihuahua, and northern Sonora) memory anchors such as the UNESCO World Heritage Site of Chaco Canyon are emotionally charged places that figure prominently in the origin stories and sacred geographies of contemporary Pueblo and Navajo peoples – indigenous groups with competing political stakes in the present. They are flashpoints for disputes over access, landuse, and knowledge claims among Native and Euroamerican groups with contradictory interests. In this paper I explore Chaco Canyon as contested memory anchor claimed by diverse factions.Fil: Van Dyke, Ruth M. Binghamton University, Binghamton, New York, Estados Unidos