Lessons Learned from Mbombela, South Africa, in Public-Private Partnerships in the Water Sector

For urban dwellers around the world, basic water services are provided by city administrations. However, in developing countries, cities lack both the human and financial resources to ensure adequate services, particularly to some of their most vulnerable populations. As a result, public entities often consider turning to the private sector for assistance, which may lead to a series of adverse and unintended consequences. The following case study describes the experiences of the South African city of Mbombela, arguably one of the most successful Public-Private Partnerships (PPPs) in the water sector in sub-Saharan Africa, through its successes and challenges

Steady-State Kinetic Modeling Constrains Cellular Resting States and Dynamic Behavior

A defining characteristic of living cells is the ability to respond dynamically to external stimuli while maintaining homeostasis under resting conditions. Capturing both of these features in a single kinetic model is difficult because the model must be able to reproduce both behaviors using the same set of molecular components. Here, we show how combining small, well-defined steady-state networks provides an efficient means of constructing large-scale kinetic models that exhibit realistic resting and dynamic behaviors. By requiring each kinetic module to be homeostatic (at steady state under resting conditions), the method proceeds by (i) computing steady-state solutions to a system of ordinary differential equations for each module, (ii) applying principal component analysis to each set of solutions to capture the steady-state solution space of each module network, and (iii) combining optimal search directions from all modules to form a global steady-state space that is searched for accurate simulation of the time-dependent behavior of the whole system upon perturbation. Importantly, this stepwise approach retains the nonlinear rate expressions that govern each reaction in the system and enforces constraints on the range of allowable concentration states for the full-scale model. These constraints not only reduce the computational cost of fitting experimental time-series data but can also provide insight into limitations on system concentrations and architecture. To demonstrate application of the method, we show how small kinetic perturbations in a modular model of platelet P2Y1 signaling can cause widespread compensatory effects on cellular resting states

Applications of micro-fluidic platforms integrating packed stationary phases

To design and fabricate novel centrifugal micro-fluidic platforms integrating packed stationary phases for solid-phase micro-extraction in a wide range of (bio)analytical applications. To design and fabricate novel micro-fluidic platforms integrating packed stationary phases capable of withstanding significant high pressures

Analyzing student travel patterns with augmented data visualizations

Visualization and visual analytics tools can provide critical support for experts and stakeholders to understand transportation flows and related human activities. Correlating and representing quantitative data with data from human actors can provide explanations for patterns and anomalies. We conducted research to compare and contrast the capabilities of several tools available for visualization and decision support as a part of an integrated urban informatics and visualization research project that develops tools for transportation planning and decision making. For this research we used the data collected by the StudentMoveTO (Toronto) survey which was conducted in the fall of 2015 by Toronto's four universities with the goal of collecting detailed data to understand travel behaviour and its effect on the daily routines of the students. This paper discusses the usefulness of new software which can allow designers to build meaningful narratives integrating 3D representations to assist in Geo-spatial analysis of the data

Distribution and kinematics of the HCN(3-2) emission down to the innermost region in the envelope of the O-rich star W Hya

We report high angular resolution observations of the HCN (3-2) line emission in the circumstellar envelope of the O-rich star W Hya with the Submillimeter Array. The proximity of this star allows us to image its molecular envelope with a spatial resolution of just ~40 AU, corresponding to about 10 times the stellar diameter. We resolve the HCN (3-2) emission and find that it is centrally peaked and has a roughly spherically symmetrical distribution. This shows that HCN is formed in the innermost region of the envelope (within ~10 stellar radii), which is consistent with predictions from pulsation-driven shock chemistry models, and rules out the scenario in which HCN forms through photochemical reactions in the outer envelope. Our model suggests that the envelope decreases steeply in temperature and increases smoothly in velocity with radius, inconsistent with the standard model for mass-loss driven by radiative pressure on dust grains. We detect a velocity gradient of ~5 km/s in the NW--SE direction over the central 40 AU. This velocity gradient is reminescent of that seen in OH maser lines, and could be caused by the rotation of the envelope or by a weak bipolar outflow.Comment: accepted for publication in ApJ

Sustainability and Justice: Challenges and Opportunities for an Open STEM Education

Open educational resources, or OER, are teaching materials that reside in the public do-main and are available under an open license. While the creation of high-quality materials and cyberinfrastructure to share these resources is important, OER are much more than static resource repositories. Vibrant OER communities function as collaboration hubs and often include librarians, instructional technologists, instructors, education researchers, funders, open-source software developers, and college administrators. Together, these in-dividuals work as a community to respond to changes in the education landscape, support student learning impacts both in terms of cost savings and student retention, and solve issues related to broadly sharing open resources on the web. This essay provides general information about OER, describes communities developing OER for science, technology, engineering, and mathematics education, and presents insights about sustainability chal-lenges. The sustainability challenges are organized according to multiple dimensions: cultural and social, economic and financial, and technological and environmental. In addition, OER provide important opportunities to address and promote social justice and open and accessible education philosophies. Knowing more about the OER landscape, sustainability challenges, and educational justice opportunities can help instructors use and contribute to this growing movement to reshape the landscape of undergraduate education