Mineral carbonation opportunities in the western United States

Mineral carbonation—the production of carbonates from carbon dioxide and alkaline earth compounds—is a candidate route for carbon capture and storage because alkali earth carbonates are stable over geologic time. Successful mineral carbonization requires a source of alkalinity near a source of carbon dioxide and a chemical pathway requiring only mild energy input. Please download the file below for full content

An open environment CT-US fusion for tissue segmentation during interventional guidance.

Therapeutic ultrasound (US) can be noninvasively focused to activate drugs, ablate tumors and deliver drugs beyond the blood brain barrier. However, well-controlled guidance of US therapy requires fusion with a navigational modality, such as magnetic resonance imaging (MRI) or X-ray computed tomography (CT). Here, we developed and validated tissue characterization using a fusion between US and CT. The performance of the CT/US fusion was quantified by the calibration error, target registration error and fiducial registration error. Met-1 tumors in the fat pads of 12 female FVB mice provided a model of developing breast cancer with which to evaluate CT-based tissue segmentation. Hounsfield units (HU) within the tumor and surrounding fat pad were quantified, validated with histology and segmented for parametric analysis (fat: -300 to 0 HU, protein-rich: 1 to 300 HU, and bone: HU>300). Our open source CT/US fusion system differentiated soft tissue, bone and fat with a spatial accuracy of ∼1 mm. Region of interest (ROI) analysis of the tumor and surrounding fat pad using a 1 mm(2) ROI resulted in mean HU of 68±44 within the tumor and -97±52 within the fat pad adjacent to the tumor (p<0.005). The tumor area measured by CT and histology was correlated (r(2) = 0.92), while the area designated as fat decreased with increasing tumor size (r(2) = 0.51). Analysis of CT and histology images of the tumor and surrounding fat pad revealed an average percentage of fat of 65.3% vs. 75.2%, 36.5% vs. 48.4%, and 31.6% vs. 38.5% for tumors <75 mm(3), 75-150 mm(3) and >150 mm(3), respectively. Further, CT mapped bone-soft tissue interfaces near the acoustic beam during real-time imaging. Combined CT/US is a feasible method for guiding interventions by tracking the acoustic focus within a pre-acquired CT image volume and characterizing tissues proximal to and surrounding the acoustic focus

The Need for Large-Scale, Longitudinal Empirical Studies in Middle Level Education Research

This essay describes and discusses the ongoing need for large-scale, longitudinal, empirical research studies focused on middle grades education. After a statement of the problem and concerns, the essay describes several prior middle grades efforts and research studies. Recommendations for future research efforts to inform policy decisions are provided, including roles for the Middle Level Education Research Special Interest Group (MLER SIG) of the American Educational Research Association (AERA) and other national organizations

Examining Doctoral Student Development of a Researcher Identity: Using the Draw a Researcher Test

With a core identity as working professionals, education doctoral students struggle with seeing themselves as researchers. Because research is essential in a doctoral program, the sooner doctoral students include researcher as an identity, the smoother and more successful their journey will be. To support doctoral student researcher identity development, we focused on scaffolding and embedding academic writing experiences in the first year seminar in a U.S. doctoral program. The purpose of this study was to describe and explain doctoral students’ development of a researcher identity as measured by the Draw-a-Researcher Test (DART). In the fall and spring, we collected drawings (DART) and narrative reflections from nine students. We created a five-dimension DART scoring guide. In the fall, the drawings revealed students’ uncertainty about the agency (ability to make changes) and the research process dimensions; in the spring, however, the drawings showed students’ clearer understanding of these two dimensions. In the narrative reflections, students noted the influence of writing expectations and experiences on their role identity as researchers. Implications, as measured by the DART, are that an embedded writing support model seems to assure the development of doctoral students’ core identity as researchers during the first year of the program

The Urban Unbanked In Mexico And The United States

This paper examines the ways in which lower-income households obtain basic financial services in urban communities in Mexico and the United States. And it discusses the efforts that private sector and government organizations are making to lower the cost or improve the quality of those services. The paper summarizes available information on these issues and assesses the rationale and challenges facing the strategies that both countries are using to improve the financial services available to lower-income households, giving particular attention to unbanked households, meaning households that do not have deposit accounts with any regulated deposit-taking institution, and also to lower-income households in large urban areas. In comparing the experiences of the two countries, the paper reviews the extent to which lower-income households are unbanked, their use of non-bank financial services, and strategies for improving financial services to the unbanked. The underlying differences between the countries\u27 typical household incomes-national income per capita in Mexico in 2002 was US$8,540, compared with$35,060 in the United States (World Bank 2003)-may also influence the difference in percentage of unbanked-9.1 percent of families in the United States compared with 76.4 percent found in a recent study in Mexico City

Survival of South African patients on renal replacement therapy

CITATION: Jardine, T. et al. Survival of South African patients on renal replacement therapy. Clinical Kidney Journal, 13(5): 782–790. doi:10.1093/ckj/sfaa012The original publication is available at https://academic.oup.com/ckjBackground The majority of South Africans rely on a resource-constrained public healthcare sector, where access to renal replacement therapy (RRT) is strictly rationed. The incidence of RRT in this sector is only 4.4 per million population (pmp), whereas it is 139 pmp in the private sector, which serves mainly the 16% of South Africans who have medical insurance. Data on the outcomes of RRT may influence policies and resource allocation. This study evaluated, for the first time, the survival of South African patients starting RRT based on data from the South African Renal Registry. Methods The cohort included patients with end-stage kidney disease who initiated RRT between January 2013 and September 2016. Data were collected on potential risk factors for mortality. Failure events included stopping treatment without recovery of renal function and death. Patients were censored at 1 year or upon recovery of renal function or loss to follow-up. The 1-year patient survival was estimated using the Kaplan–Meier method and the association of potential risk factors with survival was assessed using multivariable Cox proportional hazards regression. Results The cohort comprised 6187 patients. The median age was 52.5 years, 47.2% had diabetes, 10.2% were human immunodeficiency virus (HIV) positive and 82.2% had haemodialysis as their first RRT modality. A total of 542 patients died within 1 year of initiating RRT, and overall 1-year survival was 90.4% [95% confidence interval (CI) 89.6–91.2]. Survival was similar in patients treated in the private sector as compared with the public healthcare sector [hazard ratio 0.93 (95% CI 0.72–1.21)]. Higher mortality was associated with older age and a primary renal diagnosis of ‘Other’ or ‘Aetiology unknown’. When compared with those residing in the Western Cape, patients residing in the Northern Cape, Eastern Cape, Mpumalanga and Free State provinces had higher mortality. There was no difference in mortality based on ethnicity, diabetes or treatment modality. The 1-year survival was 95.9 and 94.2% in HIV-positive and -negative patients, respectively. One-fifth of the cohort had no data on HIV status and the survival in this group was considerably lower at 77.1% (P < 0.001). Conclusions The survival rates of South African patients accessing RRT are comparable to those in better-resourced countries. It is still unclear what effect, if any, HIV infection has on survival.https://academic.oup.com/ckj/article/13/5/782/5780430Publishers versio

Experimentally Observed Anomalies from Inclining a Vapor Compression Cycle

Vapor compression cycles would have many applications in the space industry if it was not for the uncertainty imposed by microgravity environments on two-phase systems. A first step towards Zero-G for technologies involving fluid dynamics can be terrestrial testing at different orientations. For vapor compression cycles, there is very little literature describing this type of research. This paper describes the anomalies encountered during the pursuit of a continuous operation of a R134a vapor compression cycle while positioning it at fixed angles around one axis between 0 and 360°. Experimental data was collected on a dedicated test stand across two configurations, one using a flat-plate evaporator and the other configuration using a tube-in-tube evaporator. Liquid flooding of the suction line was observed for both configurations but also continuous operation throughout a complete loop for certain cycle conditions. Charge migration towards the evaporator when it was put at the bottom was calculated based on differing measurements of the two mass flow meters in the liquid and suction line