Effects of Nose Radius and Extreme Cooling on Boundary-Layer Transition for Three Smooth 15-Cone-Cylinders in Free Flight at Mach Numbers to 8.50

Three highly polished 15- included- angle cone- cylinders with hemispherical tips of several diameters ( 2, 3, and 4 in.) have been flown in order to obtain boundary- layer transition data at very low wall to local stream temperature ratios, and heat- transfer data. All surfaces had a 2-microinch average roughness height. Laminar flow existed over the entire hemispherical nose of the 2- and 3-inch-tip- diameter models throughout the complete flight history. Extreme cooling to wall to local stream temperature ratios at the sonic point as low as 0.20 did not cause transition on the nose for diameters as large as 3 inches. However, extreme cooling did cause early transition on the 4-inch model where it appears probable that transition occurred forward of the 45 station at a wall to local stream temperature ratio of about 0.26. Variations in tip diameter influenced transition downstream of the nose under conditions of extreme cooling. The 2-inch- tip model was laminar at all cone- cylinder stations at temperature ratios as low as 0.32 whereas the 3- and 4-inch-tip models were turbulent at the same local flow conditions but at higher wall to local temperature ratios. Transition on the cone and cylinder of the 3- and 4-inch- tip bodies appeared to be sensitive to local Mach number, and occurred at higher local temperature ratios when values of local Mach number were higher. Increasing the nose diameter from 2 to 3 inches significantly changed the local flow conditions for which laminar flow existed on the cone- cylinder afterbody. However, a further increase in tip size t o a 4-inch diameter had no discernable effect on the local flow conditions at transition. The transition results of the 3- and 4-inch-nose-diameter smooth bodies are similar to those observed on a 7/8-inch-nose-diameter body with roughened surfaces. Turbulent boundary layers resulted in both cases at very low wall to local stream temperature ratios. Both laminar and turbulent heat-transfer data were in good agreement with theoretical Stanton numbers when heat-transfer reduction due to tip blunting was considered

Ethics in Locality: Confessions of a Not-So-Innocent Bystander

Using narrative form, so important in the Indigenous tradition, this paper tells the story of Ojibwa philosopher, Dennis McPherson, a friend and colleague of the author, and his persistent efforts over the years to liberate Locality

Metalloprotein Crystallography: More than a Structure

Metal ions and metallocofactors play important roles in a broad range of biochemical reactions. Accordingly, it has been estimated that as much as 25–50% of the proteome uses transition metal ions to carry out a variety of essential functions. The metal ions incorporated within metalloproteins fulfill functional roles based on chemical properties, the diversity of which arises as transition metals can adopt different redox states and geometries, dictated by the identity of the metal and the protein environment. The coupling of a metal ion with an organic framework in metallocofactors, such as heme and cobalamin, further expands the chemical functionality of metals in biology. The three-dimensional visualization of metal ions and complex metallocofactors within a protein scaffold is often a starting point for enzymology, highlighting the importance of structural characterization of metalloproteins. Metalloprotein crystallography, however, presents a number of implicit challenges including correctly incorporating the relevant metal or metallocofactor, maintaining the proper environment for the protein to be purified and crystallized (including providing anaerobic, cold, or aphotic environments), and being mindful of the possibility of X-ray induced damage to the proteins or incorporated metal ions. Nevertheless, the incorporated metals or metallocofactors also present unique advantages in metalloprotein crystallography. The significant resonance that metals undergo with X-ray photons at wavelengths used for protein crystallography and the rich electronic properties of metals, which provide intense and spectroscopically unique signatures, allow a metalloprotein crystallographer to use anomalous dispersion to determine phases for structure solution and to use simultaneous or parallel spectroscopic techniques on single crystals. These properties, coupled with the improved brightness of beamlines, the ability to tune the wavelength of the X-ray beam, the availability of advanced detectors, and the incorporation of spectroscopic equipment at a number of synchrotron beamlines, have yielded exciting developments in metalloprotein structure determination. Here we will present results on the advantageous uses of metals in metalloprotein crystallography, including using metallocofactors to obtain phasing information, using K-edge X-ray absorption spectroscopy to identify metals coordinated in metalloprotein crystals, and using UV–vis spectroscopy on crystals to probe the enzymatic activity of the crystallized protein.National Institutes of Health (U.S.) (Grant GM069857)National Institutes of Health (U.S.) (Grant F32-GM099257)National Institutes of Health (U.S.) (Grant F32-GM108189

Phase Gradient Algorithm Method for 3-D Holographic Ladar Imaging

3-D holographic ladar uses digital holography with frequency diversity to add the ability to resolve targets in range. A key challenge is that since individual frequency samples are not recorded simultaneously, differential phase aberrations may exist between them making it difficult to achieve range compression. We describe steps specific to this modality so that phase gradient algorithms (PGA) can be applied to 3-D holographic ladar data for phase corrections across multiple temporal frequency samples. Substantial improvement of range compression is demonstrated with a laboratory experiment where our modified PGA technique is applied. Additionally, the PGA estimator is demonstrated to be efficient for this application and the maximum entropy saturation behavior of the estimator is analytically described

Responsiveness to evidence : a political cognition approach

Questions of societal import have both normative (what should be done) and descriptive (what is the case) dimensions. In this chapter, we address disagreements about the latter through the lens of political cognition, a research effort spanning cognitive psychology and experimental political science. We consider various explanations for fierce disagreements about "facts on the ground" and find that first, extensive evidence shows that judgments sort by political partisanship. Second, individual differences in threat sensitivity and uncertainty tolerance predict partisan group membership, which aids understanding of group differences but not necessarily differences in descriptive beliefs. Third, no evidence suggests a historically unusual deficit in scientific understanding. Fourth, some evidence implicates well-studied features of thought (confirmation bias, motivated reasoning), but these features appear to be symmetrical across the partisan divide. Finally, emergent evidence implicates people's assessments of information sources, processes that are also susceptible to motivated reasoning and partisan cueing and moreover are challenged by a media environment that is historically unusual. We conclude that the most promising conceptualizations of disagreement over empirical matters will acknowledge that partisan cues are often valid cues indicating the beliefs of people's groups and address difficulties of information source assessment in our current, unstable information environment

The Amphibian Extinction Crisis - what will it take to put the action into the Amphibian Conservation Action Plan?

The current mass extinction episode is most apparent in the amphibians. With approximately 7,000 species, amphibians are dependent on clean fresh water and damp habitats and are considered vulnerable to habitat loss (deforestation), changes in water or soil quality and the potential impacts of climate change, and in addition many species are suffering from an epidemic caused by a chytrid fungus. Because of their sensitivity and general dependence on both terrestrial and aquatic habitats they are often regarded as indicators of the health of the environment. The latest figures from the International Union for Conservation of Nature’s (IUCN) Red List of Threatened Species™ show that there are nearly as many species of amphibians categorised as Threatened as those of Threatened birds and mammals put together, with an estimated 40% of amphibian species in danger of extinction. Furthermore, although amphibians have survived multiple previous global mass extinctions, in the last 20-40 years precipitous population declines have taken place on a scale not previously seen. Although amphibian declines were first reported in the 1950s, the magnitude and global scope of the problem were only fully realised during discussions at the 1st World Congress of Herpetology in England in 1989. Shortly thereafter, the Declining Amphibian Populations Task Force (DAPTF) was established by the IUCN Species Survival Commission (SSC) to investigate the causes and severity of the declines. Many projects and publications were stimulated by the DAPTF and the results of these prompted the IUCN to conduct a global amphibian assessment in 2004. IUCN SSC’s Amphibian Conservation Action Plan (ACAP) was published in 2007, following an Amphibian Conservation Summit held in 2005. The ACAP identified the key issues that require attention in order to curb this crisis, and provided the framework for interventions. While there have been significant efforts in the last five years, the response to the crisis has not progressed across all areas of the action plan at a scale sufficient to halt the crisis. As a direct result, species continue to decline and go extinct. Finding solutions to counter amphibian declines and extinctions is one of the greatest conservation challenges of the century, which comes with alarming and serious implications for the health of ecosystems globally. The Amphibian Survival Alliance (ASA), launched in June 2011, acts as a global partnership for amphibian conservation. It is in a pivotal position to implement the ACAP, acting to mobilise a motivated and effective consortium of organisations working together to stem the rapid losses of amphibian populations and species worldwide. The Alliance brings focus, coordination, and leadership in addressing one of the world’s most serious extinction crises. Its goal is the restoration of all threatened native amphibian species to their natural roles and population levels in ecosystems worldwide. The recently formed Amphibian Survival Alliance will address the multiple ACAP issues with several new initiatives, including creating a web-based ‘living’ version of ACAP and driving the implementation of the ACAP themes in a more progressive and collaborative manner than ever before, thereby stemming the loss of an important part of the biological diversity of our planet.   

The providing resources to enhance African American patients' readiness to make decisions about kidney disease (PREPARED) study: protocol of a randomized controlled trial.

BACKGROUND: Living related kidney transplantation (LRT) is underutilized, particularly among African Americans. The effectiveness of informational and financial interventions to enhance informed decision-making among African Americans with end stage renal disease (ESRD) and improve rates of LRT is unknown. METHODS/DESIGN: We report the protocol of the Providing Resources to Enhance African American Patients' Readiness to Make Decisions about Kidney Disease (PREPARED) Study, a two-phase study utilizing qualitative and quantitative research methods to design and test the effectiveness of informational (focused on shared decision-making) and financial interventions to overcome barriers to pursuit of LRT among African American patients and their families. Study Phase I involved the evidence-based development of informational materials as well as a financial intervention to enhance African American patients' and families' proficiency in shared decision-making regarding LRT. In Study Phase 2, we are currently conducting a randomized controlled trial in which patients with new-onset ESRD receive 1) usual dialysis care by their nephrologists, 2) the informational intervention (educational video and handbook), or 3) the informational intervention in addition to the option of participating in a live kidney donor financial assistance program. The primary outcome of the randomized controlled trial will include patients' self-reported rates of consideration of LRT (including family discussions of LRT, patient-physician discussions of LRT, and identification of a LRT donor). DISCUSSION: Results from the PREPARED study will provide needed evidence on ways to enhance the decision to pursue LRT among African American patients with ESRD