Loess Hills: A National Natural Landmark

Loess is one of the most common geologic materials found on the land surface in the Midwest. This can also be said for the lower Mississippi Valley, the Palouse district of eastern Washington, central and eastern Europe, the Ukraine of southwestern Russia and eastern China. The word itself is German in origin, and as late as the 1860s was regarded as a provincial name for deposits along the Rhine Valley. Loess, glacial history, native grasslands and productive agricultural regions are linked together across the mid-latitudes of the northern hemisphere

A Primary Mammoth Site with Associated Fauna in Pottawattamie County, Iowa

. In August 1970, an investigation was made of the remains of a mammoth, Mammuthus cf. M. columbi, exposed west of Oakland, in Pottawattamie County, Iowa. A segment of proboscidian tusk, a lower third molar, and additional skeletal fragments were collected from the Wisconsin loess. Associated with the mammoth was a small-mammal fauna consisting of Phenacomys intermedius (heather vole), Microtus pennsylvanicus (meadow vole), and Vulpes vulpes (red fox), extant species with an area of sympatry immediately north of the Minnesota-Canadian border. This fauna, here designated the Oakland local fauna, supports cooler summers in western Iowa during Wisconsin loess deposition

Iowa\u27s Loess Hills - A National Treasure

A narrow band of unusual hills skirts the Missouri River valley along Iowa\u27s western border. The steep, sharply ridged topography and the predominance of native grass and woodland cover stand in marked contrast to the orderly rolling farm fields to the east and the broad cultivated floodplain of the Missouri River to the west. These high, narrow-spurred ridges, steep slopes, and deep ravines constitute the Iowa landform region known as the Loess Hills

Geologic Overview of the Paleozoic Plateau Region of Northeastern Iowa

Steep slopes, varied slope aspects, and entrenched stream valleys carved into Paleozoic-age rocks provide the geologic framework for the unique and diverse ecology of northeastern Iowa. Differential weathering and erosion of these variable rock types resulted in irregular surface slopes in a multi-stepped, high-relief landscape. Additionally, solution of carbonate bedrock produced karst topography, cavern systems, ice caves, cold-air drainage, and perennial groundwater springs. The so-called Driftless Area in Iowa was glaciated repeatedly in Pre-Illinoian time, and should not be called Driftless. The name Paleozoic Plateau for this physiographic region more accurately describes some of its special aspects and also incorporates the much larger region of distinctive physiography and ecology referred to by biologists. Although the bedrock geology provides the framework for this unique region, the high relief is a product of more recent geologic history. Evidence from studies of the upland Quaternary stratigraphy and erosional history, the development of the karst system, and the fluvial deposits in the stream valleys reveal a complex Pleistocene history. Stream erosion since the last episode of glaciation (ca. 500,000 years before present) produced the deeply dissected landscape. Current research suggests that the major episode of deep-valley incision occurred during the Wisconsinan. Numerous late-Wisconsinan terraces stand 12-25 m above the present streams. A large portion of northeastern Iowa\u27s rugged terrain is remarkably young

Geology of the Loess Hills Region

The narrow ridges and steep bluffs which extend in a narrow band along the Missouri Valley form the Loess Hills region. These bluffs stand in sharp contrast to the flat-lying Missouri River floodplain. The unique ridge forms are composed of thick accumulations of late Wisconsinan wind-blown silt (loess). Older Quaternary deposits as well as Cretaceous and Pennsylvanian bedrock outcrop beneath the loess in the region. The intricate texture of the topography results from the combined effects of eolian deposition, fluvial erosion, and mass-wasting. Physical properties of loess allow it to maintain nearly vertical faces when exposed. These properties also produce special problems: slope instability, severe gullying, and high erosion races. The high relief and rough terrain provide slope aspects which vary widely in exposure to sun, wind, and moisture. These factors have produced a mosaic of microenvironments noted for their unusually xeric ecology

Effectiveness and cost-effectiveness of a physical activity loyalty scheme for behaviour change maintenance: a cluster randomised controlled trial

Abstract Background Increasing physical activity in the workplace can provide employee physical and mental health benefits, and employer economic benefits through reduced absenteeism and increased productivity. The workplace is an opportune setting to encourage habitual activity. However, there is limited evidence on effective behaviour change interventions that lead to maintained physical activity. This study aims to address this gap and help build the necessary evidence base for effective, and cost-effective, workplace interventions. Methods/design This cluster randomised control trial will recruit 776 office-based employees from public sector organisations in Belfast and Lisburn city centres, Northern Ireland. Participants will be randomly allocated by cluster to either the Intervention Group or Control Group (waiting list control). The 6-month intervention consists of rewards (retail vouchers, based on similar principles to high street loyalty cards), feedback and other evidence-based behaviour change techniques. Sensors situated in the vicinity of participating workplaces will promote and monitor minutes of physical activity undertaken by participants. Both groups will complete all outcome measures. The primary outcome is steps per day recorded using a pedometer (Yamax Digiwalker CW-701) for 7 consecutive days at baseline, 6, 12 and 18 months. Secondary outcomes include health, mental wellbeing, quality of life, work absenteeism and presenteeism, and use of healthcare resources. Process measures will assess intervention “dose”, website usage, and intervention fidelity. An economic evaluation will be conducted from the National Health Service, employer and retailer perspective using both a cost-utility and cost-effectiveness framework. The inclusion of a discrete choice experiment will further generate values for a cost-benefit analysis. Participant focus groups will explore who the intervention worked for and why, and interviews with retailers will elucidate their views on the sustainability of a public health focused loyalty card scheme. Discussion The study is designed to maximise the potential for roll-out in similar settings, by engaging the public sector and business community in designing and delivering the intervention. We have developed a sustainable business model using a ‘points’ based loyalty platform, whereby local businesses ‘sponsor’ the incentive (retail vouchers) in return for increased footfall to their business. Trial registration ISRCTN17975376 (Registered 19/09/2014)

Adipose segmentation in small animals at 7T: a preliminary study

<p>Abstract</p> <p>Background</p> <p>Small animal MRI at 7 Tesla (T) provides a useful tool for adiposity research. For adiposity researchers, separation of fat from surrounding tissues and its subsequent quantitative or semi- quantitative analysis is a key task. This is a relatively new field and a priori it cannot be known which specific biological questions related to fat deposition will be relevant in a specific study. Thus it is impossible to predict what accuracy and what spatial resolution will be required in all cases and even difficult what accuracy and resolution will be useful in most cases. However the pragmatic time constraints and the practical resolution ranges are known for small animal imaging at 7T. Thus we have used known practical constraints to develop a method for fat volume analysis based on an optimized image acquisition and image post processing pair.</p> <p>Methods</p> <p>We designed a fat segmentation method based on optimizing a variety of factors relevant to small animal imaging at 7T. In contrast to most previously described MRI methods based on signal intensity of T1 weighted image alone, we chose to use parametric images based on Multi-spin multi-echo (MSME) Bruker pulse sequence which has proven to be particularly robust in our laboratory over the last several years. The sequence was optimized on a T1 basis to emphasize the signal. T2 relaxation times can be calculated from the multi echo data and we have done so on a pixel by pixel basis for the initial step in the post processing methodology. The post processing consists of parallel paths. On one hand, the weighted image is precisely divided into different regions with optimized smoothing and segmentation methods; and on the other hand, a confidence image is deduced from the parametric image according to the distribution of relaxation time relationship of typical adipose. With the assistance of the confidence image, a useful software feature was implemented to which enhances the data and in the end results in a more reliable and flexible method for adipose evaluation.</p> <p>Results</p> <p>In this paper, we describe how we arrived at our recommended procedures and key aspects of the post-processing steps. The feasibility of the proposed method is tested on both simulated and real data in this preliminary research. A research tool was created to help researchers segment out fat even when the anatomical information is of low quality making it difficult to distinguish between fat and non-fat. In addition, tool is designed to allow the operator to make adjustments to many of the key steps for comparison purposes and to quantitatively assess the difference these changes make. Ultimately our flexible software lets the researcher define key aspects of the fat segmentation and quantification.</p> <p>Conclusions</p> <p>Combining the full T2 parametric information with the optimized first echo image information, the research tool enhances the reliability of the results while providing more flexible operations than previous methods. The innovation in the method is to pair an optimized and very specific image acquisition technique to a flexible but tuned image post processing method. The separation of the fat is aided by the confidence distribution of regions produced on a scale relevant to and dictated by practical aspects of MRI at 7T.</p

Generation of Priority Research Questions to Inform Conservation Policy and Management at a National Level

Integrating knowledge from across the natural and social sciences is necessary to effectively address societal tradeoffs between human use of biological diversity and its preservation. Collaborative processes can change the ways decision makers think about scientific evidence, enhance levels of mutual trust and credibility, and advance the conservation policy discourse. Canada has responsibility for a large fraction of some major ecosystems, such as boreal forests, Arctic tundra, wetlands, and temperate and Arctic oceans. Stressors to biological diversity within these ecosystems arise from activities of the country's resource-based economy, as well as external drivers of environmental change. Effective management is complicated by incongruence between ecological and political boundaries and conflicting perspectives on social and economic goals. Many knowledge gaps about stressors and their management might be reduced through targeted, timely research. We identify 40 questions that, if addressed or answered, would advance research that has a high probability of supporting development of effective policies and management strategies for species, ecosystems, and ecological processes in Canada. A total of 396 candidate questions drawn from natural and social science disciplines were contributed by individuals with diverse organizational affiliations. These were collaboratively winnowed to 40 by our team of collaborators. The questions emphasize understanding ecosystems, the effects and mitigation of climate change, coordinating governance and management efforts across multiple jurisdictions, and examining relations between conservation policy and the social and economic well-being of Aboriginal peoples. The questions we identified provide potential links between evidence from the conservation sciences and formulation of policies for conservation and resource management. Our collaborative process of communication and engagement between scientists and decision makers for generating and prioritizing research questions at a national level could be a model for similar efforts beyond Canada

[(18)F]FDG-PET/CT metabolic parameters as useful prognostic factors in cervical cancer patients treated with chemo-radiotherapy.

To compare the prognostic value of different anatomical and functional metabolic parameters determined using [(18)F]FDG-PET/CT with other clinical and pathological prognostic parameters in cervical cancer (CC). Thirty-eight patients treated with standard curative doses of chemo-radiotherapy (CRT) underwent pre- and post-therapy [(18)F]FDG-PET/CT. [(18)F]FDG-PET/CT parameters including mean tumor standardized uptake values (SUV), metabolic tumor volume (MTV) and tumor glycolytic volume (TGV) were measured before the start of CRT. The post-treatment tumor metabolic response was evaluated. These parameters were compared to other clinical prognostic factors. Survival curves were estimated by using the Kaplan-Meier method. Cox regression analysis was performed to determine the independent contribution of each prognostic factor. After 37 months of median follow-up (range, 12-106), overall survival (OS) was 71 % [95 % confidence interval (CI), 54-88], disease-free survival (DFS) 61 % [95 % CI, 44-78] and loco-regional control (LRC) 76 % [95 % CI, 62-90]. In univariate analyses the [(18)F]FDG-PET/CT parameters unfavorably influencing OS, DFS and LRC were pre-treatment TGV-cutoff ≥562 (37 vs. 76 %, p = 0.01; 33 vs. 70 %, p = 0.002; and 55 vs. 83 %, p = 0.005, respectively), mean pre-treatment tumor SUV cutoff ≥5 (57 vs. 86 %, p = 0.03; 36 vs. 88 %, p = 0.004; 65 vs. 88 %, p = 0.04, respectively) and a partial tumor metabolic response after treatment (9 vs. 29 %, p = 0.0008; 0 vs. 83 %, p &lt; 0.0001; 22 vs. 96 %, p &lt; 0.0001, respectively). After multivariate analyses a partial tumor metabolic response after treatment remained as an independent prognostic factor unfavorably influencing DFS and LRC (RR 1:7.7, p &lt; 0.0001, and RR 1:22.6, p = 0.0003, respectively) while the pre-treatment TGV-cutoff ≥562 negatively influenced OS and DFS (RR 1:2, p = 0.03, and RR 1:2.75, p = 0.05). Parameters capturing the pre-treatment glycolytic volume and metabolic activity of [(18)F]FDG-positive disease provide important prognostic information in patients with CC treated with CRT. The post-therapy [(18)F]FDG-PET/CT uptake (partial tumor metabolic response) is predictive of disease outcome