A wind-tunnel investigation of sonic-boom pressure distributions of bodies of revolution at Mach 2.96, 3.83, and 4.63

Measurements of sonic boom pressure distribution of bodies of revolution at Mach 2.96, 3.83, and 4.63 in Unitary Plan wind tunne

Space shuttle: S-IC booster/Grumman C4 orbiter determination of downwash on 900 square feet, 30 deg oriented S-IC fins and optimum orbiter body and aerodynamic surface incidence angles

Wind tunnel tests of downwash aerodynamic surface incidence angles on Saturn S-1C booster coupled to Grumman C-4 orbiter shuttl

Evaluating 35 Methods to Generate Structural Connectomes Using Pairwise Classification

There is no consensus on how to construct structural brain networks from diffusion MRI. How variations in pre-processing steps affect network reliability and its ability to distinguish subjects remains opaque. In this work, we address this issue by comparing 35 structural connectome-building pipelines. We vary diffusion reconstruction models, tractography algorithms and parcellations. Next, we classify structural connectome pairs as either belonging to the same individual or not. Connectome weights and eight topological derivative measures form our feature set. For experiments, we use three test-retest datasets from the Consortium for Reliability and Reproducibility (CoRR) comprised of a total of 105 individuals. We also compare pairwise classification results to a commonly used parametric test-retest measure, Intraclass Correlation Coefficient (ICC).Comment: Accepted for MICCAI 2017, 8 pages, 3 figure

Risk factors for homelessness among women with schizophrenia

A study of risk factors for homelessness among the severely mentally ill was extended to include women, and a case-control study of 100 indigent women with schizophrenia meeting criteria for literal homelessness and 100 such women with no history of homelessness was conducted. Subjects were recruited from shelters, clinics, and inpatient psychiatric programs in New York City. Clinical interviewers used standardized research instruments to probe three domains of risk factors: severity of mental illness, family background, and prior mental health service use. Findings adjusted for ethnicity revealed that homeless women had higher rates of a concurrent diagnosis of alcohol abuse, drug abuse, and antisocial personality disorder. Homeless women also had less adequate family support

Why does the ethnic and socio-economic composition of schools influence math achievement? The role of sense of futility and futility culture

Although a number of studies in many countries have investigated the impact of the ethnic and socio-economic composition of schools on academic performance, few studies have analyzed in detail how and why compositional features matter. This article presents an examination of whether pupils’ sense of futility and schools’ futility culture account for the impact of ethnic and socio-economic status (SES) composition of schools on the academic achievement of their pupils. Multilevel analyses of data based on a survey of 2,845 pupils (aged 10–12 years) in 68 Flemish primary schools revealed that higher proportions of immigrant and working-class pupils in a school is associated with lower levels of math achievement in both immigrant and native Belgian pupils. However, by analyzing at a deeper level, by taking control variables into account, our study found that the ethnic composition of the school no longer had a significant effect on pupils’ achievement, while the SES composition still did. Most importantly, our results indicated that the remaining impact of SES composition can be explained by pupils’ sense of futility and schools’ futility culture. The implications of these findings for educational policy are discussed

Monoclinic phase in the relaxor-based piezo-/ ferroelectric Pb(Mg1/3_{1/3}Nb2/3)O3_{2/3})O_3-PbTiO3_3 system

A ferroelectric monoclinic phase of space group $Cm$ ($M_A$ type) has been discovered in 0.65Pb(Mg$_{1/3}$Nb$_{2/3})O_3$-0.35PbTiO$_3$ by means of high resolution synchrotron X-ray diffraction. It appears at room temperature in a single crystal previously poled under an electric field of 43 kV/cm applied along the pseudocubic [001] direction, in the region of the phase diagram around the morphotropic phase boundary between the rhombohedral (R3m) and the tetragonal (P4mm) phases. The monoclinic phase has lattice parameters a = 5.692 A, b = 5.679 A, c = 4.050 A and $\beta$ = $90.15^{\circ}$, with the b$_m$-axis oriented along the pseudo-cubic [110] direction . It is similar to the monoclinic phase observed in PbZr$_{1-x}$Ti$_x$O$_3$, but different from that recently found in Pb(Zn$_{1/3}$Nb$_{2/3})O_3$-PbTiO$_3$, which is of space group $Pm$ ($M_C$ type).Comment: Revised version after referees' comments. PDF file. 6 pages, 4 figures embedde

Type IV pili interactions promote intercellular association and moderate swarming of Pseudomonas aeruginosa

Pseudomonas aeruginosa is a ubiquitous bacterium that survives in many environments, including as an acute and chronic pathogen in humans. Substantial evidence shows that P. aeruginosa behavior is affected by its motility, and appendages known as flagella and type IV pili (TFP) are known to confer such motility. The role these appendages play when not facilitating motility or attachment, however, is unclear. Here we discern a passive intercellular role of TFP during flagellar-mediated swarming of P. aeruginosa that does not require TFP extension or retraction. We studied swarming at the cellular level using a combination of laboratory experiments and computational simulations to explain the resultant patterns of cells imaged from in vitro swarms. Namely, we used a computational model to simulate swarming and to probe for individual cell behavior that cannot currently be otherwise measured. Our simulations showed that TFP of swarming P. aeruginosa should be distributed all over the cell and that TFP−TFP interactions between cells should be a dominant mechanism that promotes cell−cell interaction, limits lone cell movement, and slows swarm expansion. This predicted physical mechanism involving TFP was confirmed in vitro using pairwise mixtures of strains with and without TFP where cells without TFP separate from cells with TFP. While TFP slow swarm expansion, we show in vitro that TFP help alter collective motion to avoid toxic compounds such as the antibiotic carbenicillin. Thus, TFP physically affect P. aeruginosa swarming by actively promoting cell-cell association and directional collective motion within motile groups to aid their survival.National Institutes of HealthIndiana Clinical and Translational Sciences Institut

CVM studies on the atomic ordering in complex perovskite alloys

The atomic ordering in complex perovskite alloys is investigated by the cluster variation method (CVM). For the 1/3\{111\}-type ordered structure, the order-disorder phase transition is the first order, and the order parameter of the 1:2 complex perovskite reaches its maximum near x=0.25. For the 1/2\{111\}-type ordered structure, the ordering transition is the second order. Phase diagrams for both ordered structures are obtained. The order-disorder line obeys the linear law.Comment: 10 pages, 6 figure