Aerodynamic Load Measurements and Opening Characteristics of Automatic Leading Edge Slats on a 45 deg Sweptback Wing at Transonic Speeds

Measurements of the normal force and chord force were made on the slats of a sting-mounted wing-fuselage model through a Mach number range of 0.60 to 1.03 and at angles of attack from 0 to 20 deg at subsonic speeds and from 0 to 8 deg at Mach number 1.03. The 20-percent-chord tapered leading-edge slats extended from 25 to 95 percent of the semispan and consisted of five segments. The model wing had 45 deg sweep, an aspect ratio of 3.56, a taper ratio of 0.3, and NACA 64(06)AO07 airfoil sections. Slat forces and moments were determined for the slats in the almost-closed and open positions for spanwise extents of 35 to 95 percent and 46 to 95 percent of the semispan. The results of the investigation showed little change in the slat maximum force and moment coefficients with Mach number. The coefficients for the open and almost-closed slat positions had similar variations with angle of attack. The loads on the individual slat segments were found to increase toward the tip for moderate angles of attack and decrease toward the tip for high angles of attack. An analysis of the opening and closing characteristics of aerodynamically operated slats opening on a circular-arc path is included

The complete genome of klassevirus – a novel picornavirus in pediatric stool

<p>Abstract</p> <p>Background</p> <p>Diarrhea kills 2 million children worldwide each year, yet an etiological agent is not found in approximately 30–50% of cases. Picornaviral genera such as enterovirus, kobuvirus, cosavirus, parechovirus, hepatovirus, teschovirus, and cardiovirus have all been found in human and animal diarrhea. Modern technologies, especially deep sequencing, allow rapid, high-throughput screening of clinical samples such as stool for new infectious agents associated with human disease.</p> <p>Results</p> <p>A pool of 141 pediatric gastroenteritis samples that were previously found to be negative for known diarrheal viruses was subjected to pyrosequencing. From a total of 937,935 sequence reads, a collection of 849 reads distantly related to Aichi virus were assembled and found to comprise 75% of a novel picornavirus genome. The complete genome was subsequently cloned and found to share 52.3% nucleotide pairwise identity and 38.9% amino acid identity to Aichi virus. The low level of sequence identity suggests a novel picornavirus genus which we have designated klassevirus. Blinded screening of 751 stool specimens from both symptomatic and asymptomatic individuals revealed a second positive case of klassevirus infection, which was subsequently found to be from the index case's 11-month old twin.</p> <p>Conclusion</p> <p>We report the discovery of human klassevirus 1, a member of a novel picornavirus genus, in stool from two infants from Northern California. Further characterization and epidemiological studies will be required to establish whether klasseviruses are significant causes of human infection.</p

Northern Spotted Owl (Strix occidentalis caurina) Genome: Divergence with the Barred Owl (Strix varia) and Characterization of Light-Associated Genes

We report here the assembly of a northern spotted owl (Strix occidentalis caurina) genome. We generated Illumina paired-end sequence data at 90× coverage using nine libraries with insert lengths ranging from ∼250 to 9,600 nt and read lengths from 100 to 375 nt. The genome assembly is comprised of 8,108 scaffolds totaling 1.26 × 109 nt in length with an N50 length of 3.98 × 106 nt. We calculated the genome-wide fixation index (FST) of S. o. caurina with the closely related barred owl (Strix varia) as 0.819. We examined 19 genes that encode proteins with light-dependent functions in our genome assembly as well as in that of the barn owl (Tyto alba). We present genomic evidence for loss of three of these in S. o. caurina and four in T. alba. We suggest that most light-associated gene functions have been maintained in owls and their loss has not proceeded to the same extent as in other dim-light-adapted vertebrates

A New Threat to Honey Bees, the Parasitic Phorid Fly Apocephalus borealis

Honey bee colonies are subject to numerous pathogens and parasites. Interaction among multiple pathogens and parasites is the proposed cause for Colony Collapse Disorder (CCD), a syndrome characterized by worker bees abandoning their hive. Here we provide the first documentation that the phorid fly Apocephalus borealis, previously known to parasitize bumble bees, also infects and eventually kills honey bees and may pose an emerging threat to North American apiculture. Parasitized honey bees show hive abandonment behavior, leaving their hives at night and dying shortly thereafter. On average, seven days later up to 13 phorid larvae emerge from each dead bee and pupate away from the bee. Using DNA barcoding, we confirmed that phorids that emerged from honey bees and bumble bees were the same species. Microarray analyses of honey bees from infected hives revealed that these bees are often infected with deformed wing virus and Nosema ceranae. Larvae and adult phorids also tested positive for these pathogens, implicating the fly as a potential vector or reservoir of these honey bee pathogens. Phorid parasitism may affect hive viability since 77% of sites sampled in the San Francisco Bay Area were infected by the fly and microarray analyses detected phorids in commercial hives in South Dakota and California's Central Valley. Understanding details of phorid infection may shed light on similar hive abandonment behaviors seen in CCD

Temporal Analysis of the Honey Bee Microbiome Reveals Four Novel Viruses and Seasonal Prevalence of Known Viruses, Nosema, and Crithidia

Honey bees (Apis mellifera) play a critical role in global food production as pollinators of numerous crops. Recently, honey bee populations in the United States, Canada, and Europe have suffered an unexplained increase in annual losses due to a phenomenon known as Colony Collapse Disorder (CCD). Epidemiological analysis of CCD is confounded by a relative dearth of bee pathogen field studies. To identify what constitutes an abnormal pathophysiological condition in a honey bee colony, it is critical to have characterized the spectrum of exogenous infectious agents in healthy hives over time. We conducted a prospective study of a large scale migratory bee keeping operation using high-frequency sampling paired with comprehensive molecular detection methods, including a custom microarray, qPCR, and ultra deep sequencing. We established seasonal incidence and abundance of known viruses, Nosema sp., Crithidia mellificae, and bacteria. Ultra deep sequence analysis further identified four novel RNA viruses, two of which were the most abundant observed components of the honey bee microbiome (∼1011 viruses per honey bee). Our results demonstrate episodic viral incidence and distinct pathogen patterns between summer and winter time-points. Peak infection of common honey bee viruses and Nosema occurred in the summer, whereas levels of the trypanosomatid Crithidia mellificae and Lake Sinai virus 2, a novel virus, peaked in January

Determinants of Recombination in RNA viruses

Recombination is a driving force in the evolution of RNA viruses and the understanding of this phenomenon is critical to improving the genetic stability of live attenuated vaccines. To identify what sequence motifs are responsible for non-random patterns of mutation within similar viruses, a synthetic poliovirus 1 virus was generated with densely-spaced synonymous mutations to act as markers and a recombination map was created using a novel deep sequencing technique. This map identified multiple sequence motifs that were associated with increased or decreased local recombination, which were then engineered into a new virus to successfully modulate recombination. In contrast to frequent recombination events between strains, inter-family recombination is rare. Due to the small number of known inter-family recombinants, little is know about the determinants either for the generation of such recombinants or their viability. Deep sequencing-based viral discovery techniques were employed to discover 51 new virus species, four of which represent inter-family recombinants between the nodavirus-like superfamily and the tetraviridae. These recombination events coincided with switches between bipartite and monopartitie genome organization. No inter-family recombination events were observed in the order Picornavirales despite frequent observations of known and novel species, suggesting a predisposition towards such recombination in the Nodavirales and Tetraviridae. These studies demonstrate new techniques to study viral recombination at all taxonomic levels, describe new motifs associated with recombination and set the stage for viral engineering to control recombination

A Draft Genome of the Honey Bee Trypanosomatid Parasite <i>Crithidia mellificae</i>

<div><p>Since 2006, honey bee colonies in North America and Europe have experienced increased annual mortality. These losses correlate with increased pathogen incidence and abundance, though no single etiologic agent has been identified. <i>Crithidia mellificae</i> is a unicellular eukaryotic honey bee parasite that has been associated with colony losses in the USA and Belgium. <i>C. mellificae</i> is a member of the family Trypanosomatidae, which primarily includes other insect-infecting species (<i>e.g</i>., the bumble bee pathogen <i>Crithidia bombi</i>), as well as species that infect both invertebrate and vertebrate hosts including human pathogens (<i>e.g.,Trypanosoma cruzi</i>, <i>T. brucei</i>, and <i>Leishmania spp.</i>). To better characterize <i>C. mellificae</i>, we sequenced the genome and transcriptome of strain SF, which was isolated and cultured in 2010. The 32 megabase draft genome, presented herein, shares a high degree of conservation with the related species <i>Leishmania major.</i> We estimate that <i>C. mellificae</i> encodes over 8,300 genes, the majority of which are orthologs of genes encoded by <i>L. major</i> and other <i>Leishmania</i> or <i>Trypanosoma</i> species. Genes unique to <i>C. mellificae,</i> including those of possible bacterial origin, were annotated based on function and include genes putatively involved in carbohydrate metabolism. This draft genome will facilitate additional investigations of the impact of <i>C. mellificae</i> infection on honey bee health and provide insight into the evolution of this unique family.</p></div

The gene catalogues of <i>Leishmania major</i> and <i>Crithidia mellificae</i> are compared after ortholog analysis by INPARANOID [60].

<p>*Truncated genes at contig ends were included in this analysis for a total of 9,971 ORFs. Approximately 17% of these ORFs are incomplete ends of the same presumed gene, resulting in ∼8,300 actual genes (see Results).</p

<i>Crithidia mellificae</i> genome assembly statistics.

<p><i>Crithidia mellificae</i> genome assembly statistics.</p