Calculation of aerodynamic characteristics of STOL aircraft

Method predicts lift and pitching moment characteristics of STOL aircraft with externally-blown, jet-augmented wing-flap combinations using potential-flow approach which involves combination of two flow models. Method can accommodate multiple engines per wing panel and part-span flaps

Computation of aerodynamic interference between lifting surfaces and lift- and cruise-fans

Sequence of three computer programs predicts aerodynamic interference on lifting surfaces of transport-type aircraft which are equipped with lift and cruise fans; for example, high-bypass-ratio engine and wing-pylon tail configuration or fuselage-mounted lift-fan and wing-tail configuration

Calculation of the longitudinal aerodynamic characteristics of STOL aircraft with externally-blown jet-augmented flaps

A theoretical investigation was made to develop methods for predicting the longitudinal aerodynamic characteristics of externally-blown, jet-augmented wing-flap combinations. A potential flow analysis was used to develop two models: a wing-flap lifting surface model and a high-bypass-ratio turbofan engine wake model. Use of these two models in sequence provides for calculation of the wing-flap load distribution including the influence of the engine wake. The method can accommodate multiple engines per wing panel and part-span flaps but is limited to the case where the flow and geometry of the configuration are symmetric about a vertical plane containing the wing root chord. Comparisons of predicted and measured lift and pitching moment on unswept and swept wings with one and two engines per panel and with various flap deflection angles indicate satisfactory prediction of lift and moment for flap deflections up to 30 to 40 degrees. At higher flap angles with and without power, the method begins to overpredict lift, due probably to the appearance of flow separation on the flaps

DNA-Protein Interactions in High Definition

An elegant, genome-wide approach to define the precise DNA sequences bound by transcription factors has been developed by Rhee and Pugh

Selecting a comparison group for 5-year oral and pharyngeal cancer survivors: Two methods

BACKGROUND: To assess potential long-term consequences of cancer treatment, studies that include comparison groups are needed. These comparison groups should be selected in a way that allows the subtle long-range effects of cancer therapy to be detected and distinguishes them from the effects of aging and other risk factors. The purpose of this investigation was to test two methods of recruiting a comparison group for 5-year oral and pharyngeal cancer survivors (peer-nominated and listed sample) with emphasis on feasibility and the quality of the match. METHODS: Participants were drawn from a pool of 5-year survivors treated at a large Southeastern hospital. A peer-nominated sample was solicited from the survivors. A listed sample matched on sex, age, and zip code was purchased. Telephone interviews were conducted by a professional call center. RESULTS: The following represent our key findings: The quality of matching between survivors and listed sample was better than that between survivors and peer-nominated group in age and sex. The quality of matching between the two methods on other key variables did not differ except for education, with the peer method providing a better match for the survivors than the listed sample. The yield for the listed sample method was greater than for the peer-nominated method. The cost per completed interview was greater for the peer-nominated method than the listed sample. CONCLUSION: This study not only documents the methodological challenges in selecting a comparison group for studies examining the late effects of cancer treatment among older individuals but also documents challenges in matching groups that potentially have disproportionate levels of comorbidities and at-risk health behaviors

Locus-specific editing of histone modifications at endogenous enhancers using programmable TALE-LSD1 fusions

Mammalian gene regulation is dependent on tissue-specific enhancers that can act across large distances to influence transcriptional activity1-3. Mapping experiments have identified hundreds of thousands of putative enhancers whose functionality is supported by cell type–specific chromatin signatures and striking enrichments for disease-associated sequence variants4-11. However, these studies did not address the in vivo functions of the putative elements or their chromatin states and could not determine which genes, if any, a given enhancer regulates. Here we present a strategy to investigate endogenous regulatory elements by selectively altering their chromatin state using programmable reagents. Transcription activator–like (TAL) effector repeat domains fused to the LSD1 histone demethylase efficiently remove enhancer-associated chromatin modifications from target loci, without affecting control regions. We find that inactivation of enhancer chromatin by these fusion proteins frequently causes down-regulation of proximal genes, revealing enhancer target genes. Our study demonstrates the potential of ‘epigenome editing’ tools to characterize an important class of functional genomic elements

Upscattering of ultracold neutrons from the polymer [C_6H_(12)]_n

It is generally accepted that the main cause of ultracold neutron (UCN) losses in storage traps is upscattering to the thermal energy range by hydrogen adsorbed on the surface of the trap walls. However, the data on which this conclusion is based are poor and contradictory. Here we report a measurement, performed at the Los Alamos National Laboratory UCN source, of the average energy of the flux of upscattered neutrons after the interaction of UCN with hydrogen bound in the semicrystalline polymer PMP (trade name TPX), [C_6H_(12)]_n. Our analysis, performed with the mcnp code which applies the neutron-scattering law to UCN upscattered by bound hydrogen in semicrystalline polyethylene, [C_2H_4]_n, leads us to a flux average energy value of 26±3 meV, in contradiction to previously reported experimental values of 10 to 13 meV and in agreement with the theoretical models of neutron heating implemented in MCNP