Investigation of the aerodynamic characteristics of a lifting body in ground proximity

The use of cambered hull shapes in the next generation of lighter-than-air vehicles to enhance aerodynamic performance, together with optimized take-off manoeuvre profiles, will require a more detailed understanding of ground proximity effects for such aircraft. A series of sub-scale wind tunnel tests at Re = 1.4 x 106 on a 6:1 prolate spheroid are used to identify potential changes in aerodynamic lift, drag and pitching moment coefficients that are likely to be experienced on the vehicle hull in isolation when in close ground proximity. The experimental data is supported by a preliminary assessment of surface pressure changes using a high order panel method (PANAIR) and RANS CFD simulations to assess the flow structure. The effect of ground proximity, most evident when non-dimensional ground clearance (h/c) < 0.3, is to reduce lift coefficient, increase drag coefficient and increase the body pitching moment coefficient

The ‘Burgundian’ hat from Herjolfsnes, Greenland: new discoveries, new dates

In 1921, during Poul Nørlund’s excavation at the Norse farm Herjolfsnes, Greenland, a tall hat was recovered from the burial grounds surrounding the farm’s church, where a substantial collection of medieval garments had been recovered. This unusual hat came to symbolize not only the end of the Greenland Norse colony but also its enduring cultural links with continental European fashions, following a comment to this effect published by Nørlund himself. In 1996, the hat was dated to the early fourteenth century by Arneborg, a century earlier than Nørlund’s dating, based on stylistic comparisons with European examples. Recent research on North Atlantic textiles led to a reexamination of the hat, with different sections sampled and resubmitted for accelerated mass spectrometry dating. The results suggest that the body of the hat and its crown are of different periods with c. 100 years between them. This reanalysis of the Herjolfsnes ‘tall brimless hat’ or ‘Burgundian’ hat suggests that a considerable amount of cloth recycling took place in these North Atlantic colonies, that cloth was a valued and cherished commodity, and raises questions about the role this item of material culture role should play in discussions of identity and enduring links between Greenland and the continent

Dorset, Norse, or Thule? Technological transfers, marine mammal contamination, and AMS dating of spun yarn and textiles from the Eastern Canadian Arctic

Source at https://doi.org/10.1016/j.jas.2018.06.005.Yarn and textiles recovered from prehistoric Dorset and Thule culture sites in the Eastern Canadian Arctic have raised questions about the extent and timing of indigenous and Norse interaction in the New World, whether the yarn represents technological transfers between Greenland's Norse settlers and the Dorset, or whether these Indigenous Arctic groups had independent fiber technologies before contact with Europeans. However, the extensive use of marine mammals in northern cultural contexts, and the penetration of oils from these animals' tissues into datable terrestrial materials, has posed general problems for reliably dating sites in the Arctic and has raised questions specifically about previous efforts to date these fiber objects. In this paper, we use a recently developed protocol for removing marine mammal organic contaminants entirely from radiocarbon samples, making AMS dating possible and reliable for Arctic research. This study uses those protocols to directly date a suite of woven and spun animal fiber artifacts from five Dorset and Thule archaeological sites in the eastern Canadian Arctic. Directly dating these artifacts with marine mammal oils removed helps to answer questions about Norse contact with Dorset and Thule communities, sheds new light on the topic of indigenous fiber technologies in the North, and raises new questions about European contacts with the people of the North American Arctic prior to sustained efforts at colonization after the 18th century

Foreign investment in the Los Angeles real estate market

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 1987.Bibliography: leaves 87-89.by Michael J. Smith and Kevin P. Whalen.M.S

Effects of drinking-water filtration on Cryptosporidium Seroepidemiology, Scotland

Continuous exposure to low levels of Cryptosporidium oocysts is associated with production of protective antibodies. We investigated prevalence of antibodies against the 27-kDa Cryptosporidium oocyst antigen among blood donors in 2 areas of Scotland supplied by drinking water from different sources with different filtration standards: Glasgow (not filtered) and Dundee (filtered). During 2006–2009, seroprevalence and risk factor data were collected; this period includes 2007, when enhanced filtration was introduced to the Glasgow supply. A serologic response to the 27-kDa antigen was found for ≈75% of donors in the 2 cohorts combined. Mixed regression modeling indicated a 32% step-change reduction in seroprevalence of antibodies against Cryptosporidium among persons in the Glasgow area, which was associated with introduction of enhanced filtration treatment. Removal of Cryptosporidium oocysts from water reduces the risk for waterborne exposure, sporadic infections, and outbreaks. Paradoxically, however, oocyst removal might lower immunity and increase the risk for infection from other sources

Cocaine surface contamination and the medico-legal implications of its transfer

AbstractThe question posed by this research involves how frequently one can expect to contact cocaine in day-to-day living experiences where drug use may not normally be suspected. Issues concerning contamination are germane to medico-legal investigators who evaluate the significance of drug test results in (1) questioned deaths, (2) public health concerns, (3) drugs crimes, and (4) drug use toxicological tests potentially caused by external contamination, such as hair, sweat, and skin swabs. Previous surface studies focus mainly on currency drug contamination; few have addressed other common surfaces.Public surfaces handled by a large number of people, such as building entrance door handles, bank currency dispensing machines, food store shopping carts, and service station fuel pumps within the New Haven, Connecticut metropolitan area were tested. Socio-economically, the distribution of items tested ranged from working-class to upper-middle class areas. Results were obtained using the Securetec Drugwipe II® which is an immunological, on-site test device. Precautions were taken to avoid carry-over and other potential contamination from handling including single-use latex gloves which were pre-tested as a negative control immediately before swabbing. Analysis was performed according to the manufacturer’s instructions and in the laboratory to standardize conditions. Drugwipe II® limit of detection (LOD) is ∼50ng.Test results revealed 78% positive for cocaine substances as follows: fuel pump buttons for credit card authorization, 100% positive (n=10 individual locations); ATM machines for currency withdrawal, 100% positive (n=10 individual locations); grocery store shopping carts, 70% positive; academic building entrance doors, 30% positive (n=10); and shopping mall entrance/exit doors, 100% positive (n=5).Forensic scientists and medico-legal investigators responsible for interpreting surface test results are cautioned to consider contamination before ascribing drug activity to a specific individual. For legal proceedings these results are indicative but not conclusive because immunological tests are considered presumptive and may react with the parent substance (cocaine), related compounds (benzoylecgonine, ecgonine methyl ester, ecgonine, nor-ecgonine, and cocaethylene) and immunologically similar materials

On Optimizing the Conditional Value-at-Risk of a Maximum Cost for Risk-Averse Safety Analysis

The popularity of Conditional Value-at-Risk (CVaR), a risk functional from finance, has been growing in the control systems community due to its intuitive interpretation and axiomatic foundation. We consider a non-standard optimal control problem in which the goal is to minimize the CVaR of a maximum random cost subject to a Borel-space Markov decision process. The objective takes the form $\text{CVaR}_{\alpha}(\max_{t=0,1,\dots,N} C_t)$, where $\alpha$ is a risk-aversion parameter representing a fraction of worst cases, $C_t$ is a stage or terminal cost, and $N \in \mathbb{N}$ is the length of a finite discrete-time horizon. The objective represents the maximum departure from a desired operating region averaged over a given fraction $\alpha$ of worst cases. This problem provides a safety criterion for a stochastic system that is informed by both the probability and severity of the potential consequences of the system's trajectory. In contrast, existing safety analysis frameworks apply stage-wise risk constraints (i.e., $\rho(C_t)$ must be small for all $t$, where $\rho$ is a risk functional) or assess the probability of constraint violation without quantifying its possible severity. To the best of our knowledge, the problem of interest has not been solved. To solve the problem, we propose and study a family of stochastic dynamic programs on an augmented state space. We prove that the optimal CVaR of a maximum cost enjoys an equivalent representation in terms of the solutions to this family of dynamic programs under appropriate assumptions. We show the existence of an optimal policy that depends on the dynamics of an augmented state under a measurable selection condition. Moreover, we demonstrate how our safety analysis framework is useful for assessing the severity of combined sewer overflows under precipitation uncertainty.Comment: A shorter version is under review for IEEE Transactions on Automatic Control, submitted December 202

Protein associated with SMAD1 (PAWS1/FAM83G) is a substrate for type I bone morphogenetic protein receptors and modulates bone morphogenetic protein signalling

Bone morphogenetic proteins (BMPs) control multiple cellular processes in embryos and adult tissues. BMPs signal through the activation of type I BMP receptor kinases, which then phosphorylate SMADs 1/5/8. In the canonical pathway, this triggers the association of these SMADs with SMAD4 and their translocation to the nucleus, where they regulate gene expression. BMPs can also signal independently of SMAD4, but this pathway is poorly understood. Here, we report the discovery and characterization of PAWS1/FAM83G as a novel SMAD1 interactor. PAWS1 forms a complex with SMAD1 in a SMAD4-independent manner, and BMP signalling induces the phosphorylation of PAWS1 through BMPR1A. The phosphorylation of PAWS1 in response to BMP is essential for activation of the SMAD4-independent BMP target genes NEDD9 and ASNS. Our findings identify PAWS1 as the first non-SMAD substrate for type I BMP receptor kinases and as a novel player in the BMP pathway. We also demonstrate that PAWS1 regulates the expression of several non-BMP target genes, suggesting roles for PAWS1 beyond the BMP pathway

Genetic Attributions: Sign of Intolerance or Acceptance?

Many scholars argue that people who attribute human characteristics to genetic causes also tend to hold politically and socially problematic attitudes. More specifically, public acceptance of genetic influences is believed to be associated with intolerance, prejudice, and the legitimation of social inequities and laissez-faire policies. We test these expectations with original data from two nationally representative samples that allow us to identify the American public’s attributional patterns across 18 diverse traits. Key findings are (1) genetic attributions are actually more likely to be made by liberals, not conservatives; (2) genetic attributions are associated with higher, not lower, levels of tolerance of vulnerable individuals; and (3) genetic attributions do not correlate with unseemly racial attitudes