Geometry and kinematics of the Roisan-Cignana Shear Zone, and the orogenic evolution of the Dent Blanche Tectonic System (Western Alps)

The Dent Blanche Tectonic System (DBTS) is a composite thrust sheet derived from the previously thinned passive Adriatic continental margin. A kilometric high-strain zone, the Roisan-Cignana Shear Zone (RCSZ) defines the major tectonic boundary within the DBTS and separates it into two subunits, the Dent Blanche s.s. nappe to the northwest and the Mont Mary nappe to the southeast. Within this shear zone, tectonic slices of Mesozoic and pre-Alpine meta-sediments became amalgamated with continental basement rocks of the Adriatic margin. The occurrence of high pressure assemblages along the contact between these tectonic slices indicates that the amalgamation occurred prior to or during the subduction process, at an early stage of the Alpine orogenic cycle. Detailed mapping, petrographic and structural analysis show that the Roisan-Cignana Shear Zone results from several superimposed Alpine structural and metamorphic stages. Subduction of the continental fragments is recorded by blueschist-facies deformation, whereas the Alpine collision is reflected by a greenschist facies overprint associated with the development of large-scale open folds. The postnappe evolution comprises the development of low-angle brittle faults, followed by large-scale folding (Vanzone phase) and finally brittle extensional faults. The RCSZ shows that fragments of continental crust had been torn off the passive continental margin prior to continental collision, thus recording the entire history of the orogenic cycle. The role of preceding Permo-Triassic lithospheric thinning, Jurassic rifting, and ablative subduction processes in controlling the removal of crustal fragments from the reactivated passive continental margin is discussed. Results of this study constrain the temporal sequence of the tectono-metamorphic processes involved in the assembly of the DBTS, but they also show limits on the interpretation. In particular it remains difficult to judge to what extent precollisional rifting at the Adriatic continental margin preconditioned the efficiency of convergent processes, i.e. accretion, subduction, and orogenic exhumation.

Protected stent retriever thrombectomy prevents iatrogenic emboli in new vascular territories

INTRODUCTION Diagnostic tools to show emboli reliably and protection techniques against embolization when employing stent retrievers are necessary to improve endovascular stroke therapy. The aim of the present study was to investigate iatrogenic emboli using susceptibility-weighted imaging (SWI) in an open series of patients who had been treated with stent retriever thrombectomy using emboli protection techniques. METHODS Patients with anterior circulation stroke examined with MRI before and after stent retriever thrombectomy were assessed for iatrogenic embolic events. Thrombectomy was performed in flow arrest and under aspiration using a balloon-mounted guiding catheter, a distal access catheter, or both. RESULTS In 13 of 57 patients (22.8 %) post-interventional SWI sequences detected 16 microemboli. Three of them were associated with small ischemic lesions on diffusion-weighted imaging (DWI). None of the microemboli were located in a new vascular territory, none showed clinical signs, and all 13 patients have been rated as Thrombolysis in Cerebral Infarction (TICI) 2b (n = 3) or 3 (n = 10). Retrospective reevaluation of the digital subtraction angiography (DSA) detected discrete flow stagnation nearby the iatrogenic microemboli in four patients with a positive persistent collateral sign in one. CONCLUSION Our study demonstrates two things: First, SWI seems to be more sensitive to detect emboli than DWI and DSA and, second, proximal or distal protected stent retriever thrombectomy seems to prevent iatrogenic embolization into new vascular territories during retraction of the thrombus, but not downstream during mobilization of the thrombus. Both techniques should be investigated and refined further.

Morphological differentiation of Betula (birch) pollen in northwest North America and its palaeoecological application

Lake sediments from arcto-boreal regions commonly contain abundant Betula pollen. However, palaeoenvironmental interpretations of Betula pollen are often ambiguous because of the lack of reliable morphological features to distinguish among ecologically distinct Betula species in western North America. We measured the grain diameters and pore depths of pollen from three tree-birch species (B. papyrifera, B. kenaica and B. neoalaskana) and two shrub-birch species (B. glandulosa and B. nana), and calculated the ratio of grain diameter to pore depth (D/P ratio). No statistical difference exists in all three parameters between the shrub-birch species or between two of the tree-birch species (B. kenaica and B. papyrifera), and B. neoalaskana is intermediate between the shrub-birch and the other two tree-birch species. However, mean pore depth is significantly larger for the tree species than for the shrub species. In contrast, mean grain diameter cannot distinguish tree and shrub species. Mean D/P ratio separates tree and shrub species less clearly than pore depth, but this ratio can be used for verification. The threshold for distinguishing pollen of tree versus shrub birch lies at 2.55 μm and 8.30 for pore depth and D/P ratio, respectively. We'applied these thresholds to the analysis of Betula pollen in an Alaskan lake-sediment core spanning the past 800 years. Results show that shrub birch increased markedly at the expense of tree birch during the‘Little Ice Age’; this patten is not discernible in the profile of total birch pollen.

Decision-Support tools for assessing land degradation and realising sustainable land management, Study Case of El Mkhachbiya Catchment, Northwest of Tunisia

Land degradation is intrinsically complex and involves decisions by many agencies and individuals, land degradation map- ping should be used as a learning tool through which managers, experts and stakeholders can re-examine their views within a wider semantic context. In this paper, we introduce an analytical framework for mapping land degradation, developed by World Overview for Conservation Approaches and technologies (WOCAT) programs, which aims to develop some thematic maps that serve as an useful tool and including effective information on land degradation and conservation status. Consequently, this methodology would provide an important background for decision-making in order to launch rehabilitation/remediation actions in high-priority intervention areas. As land degradation mapping is a problem-solving task that aims to provide clear information, this study entails the implementation of WOCAT mapping tool, which integrate a set of indicators to appraise the severity of land degradation across a representative watershed. So this work focuses on the use of the most relevant indicators for measuring impacts of different degradation processes in El Mkhachbiya catchment, situated in Northwest of Tunisia and those actions taken to deal with them based on the analysis of operating modes and issues of degradation in different land use systems. This study aims to provide a database for surveillance and monitoring of land degradation, in order to support stakeholders in making appropriate choices and judge guidelines and possible suitable recommendations to remedy the situation in order to promote sustainable development. The approach is illustrated through a case study of an urban watershed in Northwest of Tunisia. Results showed that the main land degradation drivers in the study area were related to natural processes, which were exacerbated by human activities. So the output of this analytical framework enabled a better communication of land degradation issues and concerns in a way relevant for policymakers.

Alexander Campbell MacKenzie, Brustbild

Signatur des Originals: S 36/F09168

Marion MacKenzie, Rollenbild, Brustbild

Signatur des Originals: S 36/F12107

Alexander Campbell Mackenzie, Brustbild

Signatur des Originals: S 36/G03348

A standard operation procedure and a pilot water testing for herbicides in northwest Harris County, Texas

Herbicides are used to control the growth of weeds along highways, power lines, and many other urban locations. Exposure to herbicides has been linked to adverse health outcomes. This study was initiated to pretest for the presence of herbicides in multiple water sources near intersections in a corridor in the Northwest Harris County (specifically in the Highway 6/FM 1960, North Freeway 45, US 290 and S 99 corridor). Roadside water and tap water samples were collected and analyzed for herbicides using the established Environmental Protection Agency (EPA) Method 515.4: "Determination of Chlorinated Acids in Drinking Water by Liquid-Liquid Micro-extraction, Derivatization, and Fast Gas Chromatography with Electron Capture Detection." A standard operating procedure (adapted from the US EPA Method 515.4) was developed for subsequent, larger studies of environmental fate of herbicides and non-occupational exposure risks. Preliminary testing of 16 water samples was performed to pretest the existence of trace herbicides; all concentrations that were greater than the minimum reporting limits of each analyte are reported with a 99 percent confidence. This study failed to find concentrations above the limits of detection of the method in any of the samples collected on June 15, 2008. However, this does not indicate that the waters around the NW Harris County are free of herbicides and metabolites. A larger and repeated sampling in the region would be necessary to make that claim. ^

Health disparities between the United States mainland and Puerto Rico, Guam, and the United States Virgin Islands (United States territories)

Health disparities have been documented for the United States mainland. No literature was found comparing the mainland population to that of Puerto Rico, Guam, and the United States Virgin Islands (United States territories). Using Healthy Lifestyle Characteristics of non-smoking, maintaining a healthy weight, consuming fruits/vegetables daily, and exercising regularly, the health of the mainland was compared to United States territories. The research questions were: (1) Among the characteristics, what are similarities/differences between citizens of the mainland United States and territories?, (2) Among the characteristics, what are similarities/differences in how the territories compare to each other?, (3) Does the mainland and the territories meet Healthy People 2010 goals for these characteristics?, (4) Are perceptions of health concordant or discordant with the characteristics for mainlanders and Puerto Ricans? ^ Using 2007 data from Behavioral Risk Factor Surveillance System (BRFSS), frequency distributions were compared for the Healthy Lifestyle Characteristics for the mainland territories. Research found smoking rates on Guam were statistically greater than the mainland, Puerto Rico or the Virgin Islands. Healthy body mass index levels and physical activity rates were better on Guam compared to other locations. Puerto Rico had significantly more overweight and obese persons, lower fruit/vegetable consumption rates, and lower physical activity rates than the mainland, Guam and the Virgin Islands. Research found mainlanders reported statistically greater participation in regular physical activity than did Puerto Ricans and Virgin Islanders; there were significant differences in fruit/vegetable consumption rates compared to both. The research found no locations met all four of Healthy People 2010 goals. Compared to mainlanders, research showed Puerto Ricans perceive their health significantly worse.^ A better understanding is needed for how United States citizens (mainlanders and territory residents) view participation in healthy behaviors and how health is affected by participating or not in healthy behaviors. For the year examined, Healthy People 2010 goals were not achieved. This study demonstrates Puerto Ricans’ health, using the four characteristics, is significantly worse than residents in the other locations. Public health programs targeting Puerto Ricans are warranted. Finally, this study highlights the need for continued research on the relationships among the mainland and territories.^

MLST analysis of Staphylococcus aureus isolates identified in a pediatric cohort in northwest Houston

The purpose of this research was to identify S. aureus isolates among a pediatric outpatient population served by the Northwest Assistance Ministries clinic as a means of identifying unique clones using multi-locus sequence typing (MLST). DNA was extracted from previously collected isolates and seven housekeeping genes were amplified and sequenced. It was hypothesized that due to the unique demographics of the population studied, there would be a high diversity of clones identified and unique strains would exist in the population. Current literature and results from this study found this to be true. 9 strains were identified in a sample of 20 patients and 5 were unique strains. Three of 4 pairs of siblings enrolled in the study were colonized with the same strain, and all cultures known to be MRSA were novel sequence strain F. These types of genetic analyses can help identify mechanisms associated with strain colonization and spread throughout respective communities. ^

Northwest Iowa On-farm Research Soybean Yield Response to Headline Fungicide

Six years ago the Northwest Iowa On-Farm Research Project was started to cooperate with local farmers to compare crop production methods on a field scale size. Through this project, over 300 replicated comparisons have been done. Beginning in 2012, the Northwest Iowa On-Farm Research project will be recognized as a part of Iowa State University Farmer Assisted Research and Management (FARM) program. This program will also expand to southwest Iowa, north central Iowa, and central Iowa.