Isotope geochemistry and paleobiology of the Devils Lake Basin, North Dakota

Devils Lake is located in one of the largest closed basins in the northern prairies. Water and sediment samples were collected to characterize present and past hydrologic and climatic conditions in the basin. Precipitation in North Dakota exhibits a wide range of stable isotopic compositions. Precipitation samples clustered along two segments of the meteoric water line, illustrating the strong seasonal component of precipitation. Low deuterium excess in summer precipitation was indicative of higher relative humidity of the air masses originating over the Gulf of Mexico. High deuterium excess in winter precipitation is similar to the values found at Canadian stations located on the northern prairies, indicating that the origin of winter precipitation is Arctic air masses. The isotopic composition of ground-water in the Spiritwood aquifer is lighter modern precipitation, indicating that the water was recharged during colder, wetter periods. Surface water has experienced significant isotopic fractionation as a result of evaporation. Precipitation and runoff are not the only sources of recharge to Devils Lake. The intercept of the evaporation line for Devils Lake surface water and the precipitation, is more negative than precipitation and runoff. Pore water in Devils Lake is enriched in major ions and nutrients. Two geochemical processes are primarily responsible for the large dissolved-solids and nutrient concentrations in the pore water: burial of saline sediments and pore water, and microbially-mediated sulfate reduction. Bottom sediment fluxes are the dominant source of major ions and nutrients to Devils Lake. Based on, biogenic silica and the composition of organic matter (TOC, C:N, del C-13, and del N-15) in sediment cores, the paleobiologic conditions of Devils Lake can be described. High lake level stands are characterized by; increased primary productivity, increased input of detrital organic matter, and nitrogen unlimiting conditions, and low lake level stands by; decreased primary productivity, decreased input of detrital organic matter, where algal matter dominants the sedimentary organic matter

An examination of telework and the physical impacts on community and regional development

In this research, the practice of teleworking and the related physical impacts on communities and regions is examined. Telework is a relatively new form of work that substitutes information technology for travel to a regular place of work. As a result, there are potentially significant physical impacts on spatial development patterns, land use relationships, transportation systems, and environmental quality. This study first addresses the larger context of the telework phenomenon by characterizing the macroeconomic shift to an Information Economy. The body of the research focuses on home-based telecommuting and telecenter-based telecommuting, which are the two most prevalent forms of telework. In the United States, the current number of teleworkers is estimated at 20 million people, and long-term projections forecast a steady rate of adoption. The major forces facilitating the adoption of telework are identified and discussed. The findings regarding the physical impacts indicate a reduction in the number of commute trips and miles traveled, which result in lower auto emissions and potential reductions in traffic congestion. The indirect effects of telecommuting are latent demand for travel and an increased potential for dispersed development patterns. Future impacts of telework will largely be dictated by the frequency of telework activity among the growing population teleworkers projected, and the interplay of existing development factors which have generally led to the decentralization of metropolitan areas

Spatial Models to Account for Variation in Observer Effort in Bird Atlases

To assess the importance of variation in observer effort between and within bird atlas projects and demonstrate the use of relatively simple conditional autoregressive (CAR) models for analyzing grid-based atlas data with varying effort. Pennsylvania and West Virginia, United States of America. We used varying proportions of randomly selected training data to assess whether variations in observer effort can be accounted for using CAR models and whether such models would still be useful for atlases with incomplete data. We then evaluated whether the application of these models influenced our assessment of distribution change between two atlas projects separated by twenty years (Pennsylvania), and tested our modeling methodology on a state bird atlas with incomplete coverage (West Virginia). Conditional Autoregressive models which included observer effort and landscape covariates were able to make robust predictions of species distributions in cases of sparse data coverage. Further, we found that CAR models without landscape covariates performed favorably. These models also account for variation in observer effort between atlas projects and can have a profound effect on the overall assessment of distribution change. Accounting for variation in observer effort in atlas projects is critically important. CAR models provide a useful modeling framework for accounting for variation in observer effort in bird atlas data because they are relatively simple to apply, and quick to run

A Multidisciplinary Investigation of a Polycythemia Vera Cancer Cluster of Unknown Origin

Cancer cluster investigations rarely receive significant public health resource allocations due to numerous inherent challenges and the limited success of past efforts. In 2008, a cluster of polycythemia vera, a rare blood cancer with unknown etiology, was identified in northeast Pennsylvania. A multidisciplinary group of federal and state agencies, academic institutions, and local healthcare providers subsequently developed a multifaceted research portfolio designed to better understand the cause of the cluster. This research agenda represents a unique and important opportunity to demonstrate that cancer cluster investigations can produce desirable public health and scientific outcomes when necessary resources are available

A conscious mouse model of gastric ileus using clinically relevant endpoints

BACKGROUND: Gastric ileus is an unsolved clinical problem and current treatment is limited to supportive measures. Models of ileus using anesthetized animals, muscle strips or isolated smooth muscle cells do not adequately reproduce the clinical situation. Thus, previous studies using these techniques have not led to a clear understanding of the pathophysiology of ileus. The feasibility of using food intake and fecal output as simple, clinically relevant endpoints for monitoring ileus in a conscious mouse model was evaluated by assessing the severity and time course of various insults known to cause ileus. METHODS: Delayed food intake and fecal output associated with ileus was monitored after intraperitoneal injection of endotoxin, laparotomy with bowel manipulation, thermal injury or cerulein induced acute pancreatitis. The correlation of decreased food intake after endotoxin injection with gastric ileus was validated by measuring gastric emptying. The effect of endotoxin on general activity level and feeding behavior was also determined. Small bowel transit was measured using a phenol red marker. RESULTS: Each insult resulted in a transient and comparable decrease in food intake and fecal output consistent with the clinical picture of ileus. The endpoints were highly sensitive to small changes in low doses of endotoxin, the extent of bowel manipulation, and cerulein dose. The delay in food intake directly correlated with delayed gastric emptying. Changes in general activity and feeding behavior were insufficient to explain decreased food intake. Intestinal transit remained unchanged at the times measured. CONCLUSION: Food intake and fecal output are sensitive markers of gastric dysfunction in four experimental models of ileus. In the mouse, delayed gastric emptying appears to be the major cause of the anorexic effect associated with ileus. Gastric dysfunction is more important than small bowel dysfunction in this model. Recovery of stomach function appears to be simultaneous to colonic recovery

Fission Yeast Sec3 and Exo70 Are Transported on Actin Cables and Localize the Exocyst Complex to Cell Poles

The exocyst complex is essential for many exocytic events, by tethering vesicles at the plasma membrane for fusion. In fission yeast, polarized exocytosis for growth relies on the combined action of the exocyst at cell poles and myosin-driven transport along actin cables. We report here the identification of fission yeast Schizosaccharomyces pombe Sec3 protein, which we identified through sequence homology of its PH-like domain. Like other exocyst subunits, sec3 is required for secretion and cell division. Cells deleted for sec3 are only conditionally lethal and can proliferate when osmotically stabilized. Sec3 is redundant with Exo70 for viability and for the localization of other exocyst subunits, suggesting these components act as exocyst tethers at the plasma membrane. Consistently, Sec3 localizes to zones of growth independently of other exocyst subunits but depends on PIP2 and functional Cdc42. FRAP analysis shows that Sec3, like all other exocyst subunits, localizes to cell poles largely independently of the actin cytoskeleton. However, we show that Sec3, Exo70 and Sec5 are transported by the myosin V Myo52 along actin cables. These data suggest that the exocyst holocomplex, including Sec3 and Exo70, is present on exocytic vesicles, which can reach cell poles by either myosin-driven transport or random walk

Impact of nine common type 2 diabetes risk polymorphisms in Asian Indian Sikhs: PPARG2 (Pro12Ala), IGF2BP2, TCF7L2 and FTO variants confer a significant risk

<p>Abstract</p> <p>Background</p> <p>Recent genome-wide association (GWA) studies have identified several unsuspected genes associated with type 2 diabetes (T2D) with previously unknown functions. In this investigation, we have examined the role of 9 most significant SNPs reported in GWA studies: [peroxisome proliferator-activated receptor gamma 2 (<it>PPARG2</it>; rs 1801282); insulin-like growth factor two binding protein 2 (<it>IGF2BP2</it>; rs 4402960); cyclin-dependent kinase 5, a regulatory subunit-associated protein1-like 1 (<it>CDK5</it>; rs7754840); a zinc transporter and member of solute carrier family 30 (<it>SLC30A8</it>; rs13266634); a variant found near cyclin-dependent kinase inhibitor 2A (<it>CDKN2A</it>; rs10811661); hematopoietically expressed homeobox (<it>HHEX</it>; rs 1111875); transcription factor-7-like 2 (<it>TCF7L2</it>; rs 10885409); potassium inwardly rectifying channel subfamily J member 11(<it>KCNJ11</it>; rs 5219); and fat mass obesity-associated gene (<it>FTO</it>; rs 9939609)].</p> <p>Methods</p> <p>We genotyped these SNPs in a case-control sample of 918 individuals consisting of 532 T2D cases and 386 normal glucose tolerant (NGT) subjects of an Asian Sikh community from North India. We tested the association between T2D and each SNP using unconditional logistic regression before and after adjusting for age, gender, and other covariates. We also examined the impact of these variants on body mass index (BMI), waist to hip ratio (WHR), fasting insulin, and glucose and lipid levels using multiple linear regression analysis.</p> <p>Results</p> <p>Four of the nine SNPs revealed a significant association with T2D; <it>PPARG2 </it>(Pro12Ala) [odds ratio (OR) 0.12; 95% confidence interval (CI) (0.03–0.52); p = 0.005], <it>IGF2BP2 </it>[OR 1.37; 95% CI (1.04–1.82); p = 0.027], <it>TCF7L2 </it>[OR 1.64; 95% CI (1.20–2.24); p = 0.001] and <it>FTO </it>[OR 1.46; 95% CI (1.11–1.93); p = 0.007] after adjusting for age, sex and BMI. Multiple linear regression analysis revealed significant association of two of nine investigated loci with diabetes-related quantitative traits. The 'C' (risk) allele of <it>CDK5 </it>(rs 7754840) was significantly associated with decreased HDL-cholesterol levels in both NGT (p = 0.005) and combined (NGT and T2D) (0.005) groups. The less common 'C' (risk) allele of <it>TCF7L2 </it>(rs 10885409) was associated with increased LDL-cholesterol (p = 0.010) in NGT and total and LDL-cholesterol levels (p = 0.008; p = 0.003, respectively) in combined cohort.</p> <p>Conclusion</p> <p>To our knowledge, this is first study reporting the role of some recently emerged loci with T2D in a high risk population of Asian Indian origin. Further investigations are warranted to understand the pathway-based functional implications of these important loci in T2D pathophysiology in different ethnicities.</p