Computational design of natural laminar flow wings for transonic transport application

Two research programs are described which directly relate to the application of natural laminar flow (NLF) technology to transonic transport-type wind planforms. Each involved using state-of-the-art computational methods to design three-dimensional wing contours which generate significant runs of favorable pressure gradients. The first program supported the Variable Sweep Transition Flight Experiment and involves design of a full-span glove which extends from the leading edge to the spoiler hinge line on the upper surface of an F-14 outer wing panel. Boundary-layer and static-pressure data will be measured on this design during the supporting wind-tunnel and flight tests. These data will then be analyzed and used to infer the relationship between crossflow and Tollmein-Schlichting disturbances on laminar boundary-layer transition. A wing was designed computationally for a corporate transport aircraft in the second program. The resulting wing design generated favorable pressure gradients from the leading edge aft to the mid-chord on both upper and lower surfaces at the cruise design point. Detailed descriptions of the computational design approach are presented along with the various constraints imposed on each of the designs. Wing surface pressure distributions, which support the design objective and were derived from transonic three-dimensional analyses codes, are also presented. Current status of each of the research programs is included in the summary

A proposed mechanism for enhanced water-conservation in egg clutches of the Mexican Kingsnake, Lampropeltis mexicana (Serpentes: Colubridae)

A postura de ovos em um substrato úmido minimiza o estresse hídrico de ovos de répteis com casca coriácea, pois permite que absorvam água através da casca permeável. Esse ganho de água contribui para a redução da perda de água em ovos agregados. Demostramos aqui essa característica de conservação de água em ovos da serpente Lampropeltis mexicana em um experimento de balanco hídrico investigando tanto desovas naturais como ovos arranjados experimentalmente em grupos. As taxas de perda de água dos ovos continuam a diminuir à medida que mais ovos são adicionados ao agregado, com um limiar de aproximadamente 15 ovos. Não há redução adicional da taxa de perda de água em um agregado de 20 ovos, número maior que o tamanho típico máximo da desova natural dessa espécie. Correntes de ar seco dirigidas sobre a desova provocam o desaparecimento dessa característica de conservação de água, mas esta reaparece quando o ar está imóvel (desligando-se a corrente de ar). Essa é a primeira vez que um aumento na pressão de vapor de água em um agregado de ovos é demonstrado experimentalmente; os resultados sugerem que a postura de ovos agregados pode beneficiar o desenvolvimento por meio da conservação de umidade.Laying eggs on a wet substrate minimizes water stress for flexible-shelled reptile eggs because they absorb water through the permeable shell. This water gain contributes to reduced water-loss in aggregated eggs. This water-conserving feature is demonstrated in eggs of Lampropeltis mexicana in a water-balance experiment investigating both naturally laid clutches and eggs in arranged clusters. Water-loss rates of eggs decrease as more eggs are added to the aggregation, with a threshold at approximately 15 eggs. There is no further reduction in water-loss rate for eggs in an aggregation of 20, which exceeds the typical maximum for natural clutch size in this species. Blowing dry air over the egg clutch causes this water-conserving feature to disappear, but it re-appears when the air is still (air current turned off). This is the first time that an increase in water-vapor pressure in an aggregation of eggs has been demonstrated experimentally; the results suggest that laying aggregations of eggs may benefit development through moisture conservation

(Errors in statistical tests)3

In 2004, Garcia-Berthou and Alcaraz published "Incongruence between test statistics and P values in medical papers," a critique of statistical errors that received a tremendous amount of attention. One of their observations was that the final reported digit of p-values in articles published in the journal Nature departed substantially from the uniform distribution that they suggested should be expected. In 2006, Jeng critiqued that critique, observing that the statistical analysis of those terminal digits had been based on comparing the actual distribution to a uniform continuous distribution, when digits obviously are discretely distributed. Jeng corrected the calculation and reported statistics that did not so clearly support the claim of a digit preference. However delightful it may be to read a critique of statistical errors in a critique of statistical errors, we nevertheless found several aspects of the whole exchange to be quite troubling, prompting our own meta-critique of the analysis

Feynman's interpretation of quantum theory

A historically important but little known debate regarding the necessity and meaning of macroscopic superpositions, in particular those containing different gravitational fields, is discussed from a modern perspective.Comment: Published version for Eur.Phys.J. H. 15 pages pdf. Final version available at http://www.springerlink.com/openurl.asp?genre=article&id=doi:10.1140/epjh/e2011-10035-

Drug resistance outcomes of long-term ART with tenofovir disoproxil fumarate in the absence of virological monitoring

Objectives: The resistance profiles of patients receiving long-term ART in sub-Saharan Africa have been poorly described. This study obtained a sensitive assessment of the resistance patterns associated with long-term tenofovir-based ART in a programmatic setting where virological monitoring is yet to become part of routine care. Methods: We studied subjects who, after a median of 4.2 years of ART, replaced zidovudine or stavudine with tenofovir disoproxil fumarate while continuing lamivudine and an NNRTI. Using deep sequencing, resistance-associated mutations (RAMs) were detected in stored samples collected at tenofovir introduction (T0) and after a median of 4.0 years (T1). Results: At T0, 19/87 (21.8%) subjects showed a detectable viral load and 8/87 (9.2%) had one or more major NNRTI RAMs, whereas 82/87 (94.3%) retained full tenofovir susceptibility. At T1, 79/87 (90.8%) subjects remained on NNRTI-based ART, 5/87 (5.7%) had introduced lopinavir/ritonavir due to immunological failure, and 3/87 (3.4%) had interrupted ART. Whilst 68/87 (78.2%) subjects maintained or achieved virological suppression between T0 and T1, a detectable viral load with NNRTI RAMs at T0 predicted lack of virological suppression at T1. Each treatment interruption, usually reflecting unavailability of the dispensary, doubled the risk of T1 viraemia. Tenofovir, lamivudine and efavirenz selected for K65R, K70E/T, L74I/V and Y115F, alongside M184V and multiple NNRTI RAMs; this resistance profile was accompanied by high viral loads and low CD4 cell counts. Conclusions: Viraemia on tenofovir, lamivudine and efavirenz led to complex resistance patterns with implications for continued drug activity and risk of onward transmission

Analysis of Rediscovered Data from Apollo 17's Lunar Seismic Profiling Experiment: Evidence for Events Associated with Sunrise

No abstract availabl

Evolution of the Near-Infrared Tully-Fisher Relation: Constraints on the Relationship Between the Stellar and Total Masses of Disk Galaxies since z=1

Using a combination of Keck spectroscopy and near-infrared imaging, we investigate the K-band and stellar mass Tully-Fisher relation for 101 disk galaxies at 0.2 < z < 1.2, with the goal of placing the first observational constraints on the assembly history of halo and stellar mass. Our main result is a lack of evolution in either the K-band or stellar mass Tully-Fisher relation from z = 0 - 1.2. Furthermore, although our sample is not statistically complete, we consider it suitable for an initial investigation of how the fraction of total mass that has condensed into stars is distributed with both redshift and total halo mass. We calculate stellar masses from optical and near-infrared photometry and total masses from maximum rotational velocities and disk scale lengths, utilizing a range of model relationships derived analytically and from simulations. We find that the stellar/total mass distribution and stellar-mass Tully-Fisher relation for z > 0.7 disks is similar to that at lower redshift, suggesting that baryonic mass is accreted by disks along with dark matter at z < 1, and that disk galaxy formation at z < 1 is hierarchical in nature. We briefly discuss the evolutionary trends expected in conventional structure formation models and the implications of extending such a study to much larger samples.Comment: ApJ, in press, 9 page

Bat Occupancy Estimates and Species Richness at Cache River National Wildlife Refuge

Six bat species of special concern, threatened or endangered, may occur in one of Arkansas’ largest bottomland hardwood forests, the Cache River National Wildlife Refuge (CRNWR). However, inventory of bat species throughout the refuge has been lacking and management plans may not be adequate in promoting bat conservation. The objectives of this study were to inventory bat species in the CRNWR, and determine bat-habitat associations via occupancy estimates. From May–August 2014 and 2015, we mist-netted from sunset for 5 hours. We also deployed bioacoustic devices throughout 5 habitat types (cypress-tupelo [dominantly Taxodium distichum and Nyssa aquatica], emergent wetland, mature forest, hardwood reforestation, and managed hardwood). Mist-netting yielded 460 bat captures with Rafinesque’s big-eared bats (Corynorhinus rafinesquii; n = 156) being the most common capture, followed by eastern red bats (Lasiurus borealis; n = 104), southeastern myotis (Myotis austroriparius; n = 91), evening bats (Nycticeius humeralis; n = 58), tri-colored bats (Perimyotis subflavus; n = 54), and a big-brown bat (Eptesicus fuscus; n = 1). Based on 3,896 calls identified with 85% certainty, evening bats and rarer big-brown bats tended to occupy managed hardwood forests more than any other habitat (occupancy probabilities ± SE: Ψ = 0.75 ± 0.13 and 0.38 ± 0.19, respectively). Tri-colored bats tended to be more present in mature forest habitats (Ψ = 0.91 ± 0.09), and Myotis species tended to have highest occupancy rates in cypress-tupelo stands (Ψ = 0.59 ± 0.15). Not all species were detected with both methods. Thus, we encourage future studies to combine mist-netting and acoustic surveying methods to minimize bias in species presence estimate. This would ensure management practices that would benefit all present species

Mutational Analysis in Pediatric Thyroid Cancer and Correlations with Age, Ethnicity, and Clinical Presentation.

BackgroundWell-differentiated thyroid cancer (WDTC) incidence in pediatrics is rising, most being papillary thyroid carcinoma (PTC). The objective of the study was to assess the prevalence of different mutations in pediatric WDTC and correlate the genotype with the clinical phenotype.MethodsThis is a single-center retrospective study. Thyroid tissue blocks from 42 consecutive pediatric WDTC patients who underwent thyroidectomy between 2001 and 2013 were analyzed at Quest Diagnostics for BRAF(V600E), RAS mutations (N,K,H), and RET/PTC and PAX8/PPARγ rearrangements, using validated molecular methods. Thyroid carcinomas included PTC, follicular thyroid carcinoma (FTC), and follicular variant of PTC (FVPTC).ResultsThirty-nine samples (29 females) were genotyped. The mean age at diagnosis was 14.7 years (range 7.9-18.4 years), and most were Hispanic (56.4%) or Caucasian (35.9%). The mean follow-up period was 2.9 years. Mutations were noted in 21/39 (53.8%), with both BRAF(V600E) (n = 9), and RET/PTC (n = 6) detected only in PTC. Mutations were detected in 2/5 FTC (PAX8/PPARγ and NRAS) and 3/6 FVPTC cases (PAX8/PPARγ). Of 28 PTC patients, 57.1% had mutations: 32.1% with BRAF(V600E), 21.4% with RET/PTC, and 3.6% with NRAS. Of patients with BRAF(V600E), 77.8% were Hispanic and 88.9% were &gt;15 years, while all RET/PTC-positive patients were ≤15 years (p = 0.003). Tumor size, lymph node involvement, and distant metastasis at diagnosis (or soon after (131)I ablation) did not vary significantly based on the mutation.ConclusionsBRAF(V600E) was the most common mutation, especially in older and Hispanic adolescents. A larger, ethnically diverse pediatric cohort followed long term will enable the genotypic variability, clinical presentation, and response to therapy to be better assessed