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

Chauffeur braking

An experienced driver will `feather' the brakes so as to unwind the suspension compliance and stop the vehicle with only just enough torque in the brakes to hold the vehicle stationary on any gradient, or against the residual torque from an automatic transmission’s torque converter. An optimal stopping problem that minimises the total jerk was formulated and solved. This model was extended by including a linear relationship between the brake pressure and the acceleration of the car where the coefficients are estimated by linear regression. Finally, a Kalman filter estimates the state of the car using the tone wheel

Una perspectiva Social Cognitiva de la transición entre la escuela y el trabajo

Este artículo propone a la Teoría Social Cognitiva del Desarrollo de Carrera (SCCT; Lent, Brown, & Hackett, 1994) como una ventajosa perspectiva para comprender el proceso de transición entre la escuela y el trabajo. En lugar de enfatizar solo el período inmediatamente precedente al egreso de la escuela media, la perspectiva SCCT del proceso de transición entre la escuela y el trabajo se concentra en seis aspectos relacionados evolutivamente que se manifiestan a través de los años escolares. El énfasis en estos seis temas (formación de autoeficacia y expectativas de resultados, desarrollo de los intereses, relaciones entre intereses y metas, traducción de metas en acciones, ejecución de  destrezas; negociación de apoyos y obstáculos de transición) sugiere múltiples metas e intervenciones tendientes a facilitar el desarrollo de carrera de los estudiantes durante los años de escuela y después del ingreso al trabajo

Train Positioning Using Video Odometry

Reliable Data Systems have developed a video-based odometry system that enables trains to measure velocities and distances travelled without the need for trackside infrastructure. The Study Group was asked to investigate ways of improving the accuracy of such a system, and to suggest any improvements that might be made. The work performed in the week followed along these strands: (a). Elimination of errors in video odometery induced by pitch and height; (b) Robust calculation of (i) the train velocity and (ii) the track curvature; (c). Accurate determination of the position of a train on a track by assimilating Curvature information; (d). Determining where on UK’s railway map a train journey takes place, based purely on video odometry and (e). Drawing a track map

Nonalcoholic fatty liver disease, liver fibrosis, and structural brain imaging: The Cross-Cohort Collaboration

Background and purpose Prior studies reported conflicting findings regarding the association of nonalcoholic fatty liver disease (NAFLD) and liver fibrosis with measures of brain health. We examined whether NAFLD and liver fibrosis are associated with structural brain imaging measures in middle- and old-age adults. Methods In this cross-sectional study among dementia- and stroke-free individuals, data were pooled from the Offspring and Third Generation cohorts of the Framingham Heart Study (FHS), the Rotterdam Study (RS), and the Study of Health in Pomerania. NAFLD was assessed through abdominal imaging. Transient hepatic elastography (FibroScan) was used to assess liver fibrosis in FHS and RS. Linear regression models were used to explore the relation of NAFLD and liver fibrosis with brain volumes, including total brain, gray matter, hippocampus, and white matter hyperintensities, adjusting for potential confounders. Results were combined using fixed effects meta-analysis. Results In total, 5660 and 3022 individuals were included for NAFLD and liver fibrosis analyses, respectively. NAFLD was associated with smaller volumes of total brain (β = −3.5, 95% confidence interval [CI] = −5.4 to −1.7), total gray matter (β = −1.9, 95% CI = −3.4 to −0.3), and total cortical gray matter (β = −1.9, 95% CI = −3.7 to −0.01). In addition, liver fibrosis (defined as liver stiffness measure ≥8.2 kPa) was related to smaller total brain volumes (β = −7.3, 95% CI = −11.1 to −3.5). Heterogeneity between studies was low. Conclusions NAFLD and liver fibrosis may be directly related to brain aging. Larger and prospective studies are warranted to validate these findings and identify liver-related preventive strategies for neurodegeneration

Chagas Disease in a Domestic Transmission Cycle in Southern Texas, USA

After three dogs died from acute Chagas cardiomyopathy at one location, an investigation was conducted of the home, garage, and grounds of the owner. A serologic study was conducted on stray dogs, and an ecologic niche model was developed to predict areas where the vector Trypanosoma gerstaeckeri might be expected

Addressing marine and coastal governance conflicts at the interface of multiple sectors and jurisdictions

Marine and coastal activities are closely interrelated, and conflicts among different sectors can undermine management and conservation objectives. Governance systems for fisheries, power generation, irrigation, aquaculture, marine biodiversity conservation, and other coastal and maritime activities are typically organized to manage conflicts within sectors, rather than across them. Based on the discussions around eight case studies presented at a workshop held in Brest in June 2019, this paper explores institutional approaches to move beyond managing conflicts within a sector. We primarily focus on cases where the groups and sectors involved are heterogeneous in terms of: the jurisdiction they fall under; their objectives; and the way they value ecosystem services. The paper first presents a synthesis of frameworks for understanding and managing cross-sectoral governance conflicts, drawing from social and natural sciences. We highlight commonalities but also conceptual differences across disciplines to address these issues. We then propose a novel analytical framework which we used to evaluate the eight case studies. Based on the main lessons learned from case studies, we then discuss the feasibility and key determinants of stakeholder collaboration as well as compensation and incentive schemes. The discussion concludes with future research needs to support policy development and inform integrated institutional regimes that consider the diversity of stakeholder interests and the potential benefits of cross-sectoral coordination

Nonalcoholic fatty liver disease, liver fibrosis, and structural brain imaging:The Cross-Cohort Collaboration

Background and purpose:Prior studies reported conflicting findings regarding the association of nonalcoholic fatty liver disease (NAFLD) and liver fibrosis with measures of brain health. We examined whether NAFLD and liver fibrosis are associated with structural brain imaging measures in middle- and old-age adults. Methods: In this cross-sectional study among dementia- and stroke-free individuals, data were pooled from the Offspring and Third Generation cohorts of the Framingham Heart Study (FHS), the Rotterdam Study (RS), and the Study of Health in Pomerania. NAFLD was assessed through abdominal imaging. Transient hepatic elastography (FibroScan) was used to assess liver fibrosis in FHS and RS. Linear regression models were used to explore the relation of NAFLD and liver fibrosis with brain volumes, including total brain, gray matter, hippocampus, and white matter hyperintensities, adjusting for potential confounders. Results were combined using fixed effects meta-analysis. Results:In total, 5660 and 3022 individuals were included for NAFLD and liver fibrosis analyses, respectively. NAFLD was associated with smaller volumes of total brain (β = −3.5, 95% confidence interval [CI] = −5.4 to −1.7), total gray matter (β = −1.9, 95% CI = −3.4 to −0.3), and total cortical gray matter (β = −1.9, 95% CI = −3.7 to −0.01). In addition, liver fibrosis (defined as liver stiffness measure ≥8.2 kPa) was related to smaller total brain volumes (β = −7.3, 95% CI = −11.1 to −3.5). Heterogeneity between studies was low. Conclusions:NAFLD and liver fibrosis may be directly related to brain aging. Larger and prospective studies are warranted to validate these findings and identify liver-related preventive strategies for neurodegeneration.</p