1,781 research outputs found
An experimental and theoretical investigation of thick wings at various sweep angles in and out of ground effect
The effects of sweep and aspect ratio on the longitudinal aerodynamics of a wing in and out of ground effect are analyzed. Experimental data were obtained in the Langley 4 by 7 Meter Tunnel for a wing with various sweep angles, aspect ratios, and flap deflections both in and out of ground effect. Theoretical predictions of the out of ground effect lift coefficients and flap effectiveness and the in ground effect lift coefficients are compared with the experimental results. As expected, the lift curve slope and flap effectiveness are reduced when the aspect ratio is reduced or the sweep angle is increased both in and out of ground effect. In ground effect, the lift and flap effectiveness are increased above a wing height to span ratio of 0.15. However, with flap deflections less than or equal to 10 deg and an angle of attack near 0 deg lift is markedly decreased at very low heights above the ground plane. This trend is not predicted by planar theoretical models but is predicted by a surface panel method where thickness effects are included
Effect of sweep and aspect ratio on the longitudinal aerodynamics of a spanloader wing in and out of ground effect
A wind tunnel investigation was conducted in the Langley 4 by 7 meter tunnel to determine the effects of leading edge sweep, aspect ratio, flap deflection, and elevon deflection on the longitudinal aerodynamic characteristics of a span distributed load advanced cargo aircraft (spanloader). Model configurations consisted of leading edge sweeps of 0, 15, 30 and 45 deg and aspect ratios of approximately 2, 4, 6, and 8. Data were obtained for angles of attack of -8 to 18 deg out of ground effect and at angles of attack of -2, 0, and 2 deg in ground effect at Mach number equal 0.14. Flap and elevon deflections ranged from -20 to 20 deg. The data are represented in tabulated form
The Moderating Role of Sex on Gender Role Orientation’s Meditation of Work-Family/Family-Work Conflict and Satisfaction Outcomes
While biological sex has been examined in the work-family interface, findings have been inconsistent in determining if males and females differ in their experiences of work-family conflict (WFC) and family-work conflict (FWC), and how conflict impacts their job, family, and life satisfaction. These inconsistent findings may be due to the changing roles of men and women, as not all men and women are adhering to traditional gender roles. Furthermore, many researchers have used incorrect terminology, indicating that they examined gender, when they actually assessed sex. Thus, the current study’s purpose was to address the shortcomings of the previous literature by examining how male and females’ gender role orientation (one’s degree of conformity to his or her traditional gender roles) mediated the relationship between WFC/FWC and job, family, and life satisfaction. Approximately 400 working adults were sampled using Amazon’s Mechanical Turk. Preliminary analyses found that having children related to more FWC, having younger children related to more FWC and more family satisfaction, having only one child living in the home related to less job satisfaction, viewing one’s job as a career related to more job and life satisfaction, higher levels of education related to more FWC, and higher levels of the participant’s spouse’s education related to more FWC and WFC. Following preliminary analyses, a structural equation modeling approach was employed, finding significant direct effects for WFC and job satisfaction and WFC and life satisfaction. It was found that gender role orientation did not mediate any paths between WFC and FWC and satisfaction outcomes. Thus, examining sex as a moderator of gender role orientation’s mediation could not be conducted. However, due to finding significant direct effects, analyses were run to determine if sex moderated any direct paths between conflict and satisfaction outcomes, finding that sex was not a significant moderator. Lastly, it was found that females adhered to more egalitarian gender roles than males. Results obtained from this study add support for interventions in the workplace to increase job satisfaction and life satisfaction as well as interventions in the home domain to increase family satisfaction
\u3cem\u3eDe Novo\u3c/em\u3e [PSI\u3csup\u3e+\u3c/sup\u3e] Prion Formation Involves Multiple Pathways to Form Infectious Oligomers
Prion and other neurodegenerative diseases are associated with misfolded protein assemblies called amyloid. Research has begun to uncover common mechanisms underlying transmission of amyloids, yet how amyloids form in vivo is still unclear. Here, we take advantage of the yeast prion, [PSI +], to uncover the early steps of amyloid formation in vivo. [PSI +] is the prion form of the Sup35 protein. While [PSI +] formation is quite rare, the prion can be greatly induced by overexpression of the prion domain of the Sup35 protein. This de novo induction of [PSI +] shows the appearance of fluorescent cytoplasmic rings when the prion domain is fused with GFP. Our current work shows that de novoinduction is more complex than previously thought. Using 4D live cell imaging, we observed that fluorescent structures are formed by four different pathways to yield [PSI +] cells. Biochemical analysis of de novo induced cultures indicates that newly formed SDS resistant oligomers change in size over time and lysates made from de novo induced cultures are able to convert [psi −] cells to [PSI +] cells. Taken together, our findings suggest that newly formed prion oligomers are infectious
The Effects of Vision Impairment on Balance in Athletes and Non-Athletes
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A Possible Stellar Metallic Enhancement in Post-T Tauri Stars by a Planetesimal Bombardment
The photospheres of stars hosting planets have larger metallicity than stars
lacking planets. In the present work we study the possibility of an earlier
metal enrichment of the photospheres by means of impacting planetesimals during
the first 20-30Myr. Here we explore this contamination process by simulating
the interactions of an inward migrating planet with a disc of planetesimal
interior to its orbit. The results show the percentage of planetesimals that
fall on the star. We identified the dependence of the planet's eccentricity
() and time scale of migration () on the rate of infalling
planetesimals. For very fast migrations (yr and yr) there
is no capture in mean motion resonances, independently of the value of .
Then, due to the planet's migration the planetesimals suffer close approaches
with the planet and more than 80% of them are ejected from the system. For slow
migrations (yr and yr) the percentage of collisions with
the planet decrease with the increase of the planet's eccentricity. For
and most of the planetesimals were captured in the 2:1 resonance and
more than 65% of them collided with the star. Whereas migration of a Jupiter
mass planet to very short pericentric distances requires unrealistic high disc
masses, these requirements are much smaller for smaller migrating planets. Our
simulations for a slowly migrating 0.1 planet, even demanding
a possible primitive disc three times more massive than a primitive solar
nebula, produces maximum [Fe/H] enrichments of the order of 0.18 dex. These
calculations open possibilities to explain hot Jupiters exoplanets
metallicities.Comment: Accepted for publication by Monthly Notices of the Royal Astronomical
Societ
Individual-specific changes in the human gut microbiota after challenge with enterotoxigenic Escherichia coli and subsequent ciprofloxacin treatment
Acknowledgements The authors wish to thank Mark Stares, Richard Rance, and other members of the Wellcome Trust Sanger Institute’s 454 sequencing team for generating the 16S rRNA gene data. Lili Fox Vélez provided editorial support. Funding IA, JNP, and MP were partly supported by the NIH, grants R01-AI-100947 to MP, and R21-GM-107683 to Matthias Chung, subcontract to MP. JNP was partly supported by an NSF graduate fellowship number DGE750616. IA, JNP, BRL, OCS and MP were supported in part by the Bill and Melinda Gates Foundation, award number 42917 to OCS. JP and AWW received core funding support from The Wellcome Trust (grant number 098051). AWW, and the Rowett Institute of Nutrition and Health, University of Aberdeen, receive core funding support from the Scottish Government Rural and Environmental Science and Analysis Service (RESAS).Peer reviewedPublisher PD
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