Increasing Collegiate Flight Training Fleet Utilization Through the Use of an Aircraft Assignment Algorithm

The operational efficiency of fleet aircraft employed for student flight training in collegiate aviation programs is strongly influenced by scheduling, among other factors. The average utilization rate for the fleet operated by the Purdue University School of Aviation and Transportation Systems was found to be 24% (Avery, 2014), and there is no data to suggest that that this rate is atypical in similar institutional programs. Mott and Bullock (2015) identified several means by which the utilization rate could be increased, and improvements in the dispatch and scheduling process were a key component of those recommendations. This article describes a scheduling algorithm that was implemented at Purdue University in the fall semester of 2015. The algorithm is a linear programming technique that incorporates optimization constraints unique to collegiate flight training operations. The resulting improvements in aircraft utilization will facilitate an increased matriculation rate of students into the flight program, thereby allowing the allocation of fixed costs over a wider user base and the reduction of overall program fees for all students. Those improvements are validated through measurement of the reduction of the cumulative turn times between aircraft operations

Facial Thermal and Blood Perfusion Patterns of Human Emotions: Proof-of-Concept

In this work, a preliminary study of proof-of-concept was conducted to evaluate the performance of the thermographic and blood perfusion data when emotions of positive and negative valence are applied, where the blood perfusion data are obtained from the thermographic data. The images were obtained for baseline, positive, and negative valence according to the protocol of the Geneva Affective Picture Database. Absolute and percentage differences of average values of the data between the valences and the baseline were calculated for different regions of interest (forehead, periorbital eyes, cheeks, nose and upper lips). For negative valence, a decrease in temperature and blood perfusion was observed in the regions of interest, and the effect was greater on the left side than on the right side. In positive valence, the temperature and blood perfusion increased in some cases, showing a complex pattern. The temperature and perfusion of the nose was reduced for both valences, which is indicative of the arousal dimension. The blood perfusion images were found to be greater contrast; the percentage differences in the blood perfusion images are greater than those obtained in thermographic images. Moreover, the blood perfusion images, and vasomotor answer are consistent, therefore, they can be a better biomarker than thermographic analysis in identifying emotions.Comment: 22 pages, 9 figure

Charged Annular Disks and Reissner-Nordstr\"{o}m Type Black Holes from Extremal Dust

We present the first analytical superposition of a charged black hole with an annular disk of extremal dust. In order to obtain the solutions, we first solve the Einstein-Maxwell field equations for sources that represent disk-like configurations of matter in confomastatic spacetimes by assuming a functional dependence among the metric function, the electric potential and an auxiliary function,which is taken as a solution of the Laplace equation. We then employ the Lord Kelvin Inversion Method applied to models of finite extension in order to obtain annular disks. The structures obtained extend to infinity, but their total masses are finite and all the energy conditions are satisfied. Finally, we observe that the extremal Reissner-Nordstr\"{o}m black hole can be embedded into the center of the disks by adding a boundary term in the inversion.Comment: 17 revtex pages, 8 eps figure

Butterflies (Lepidoptera : Hesperioidea-Papilionoidae) from the tropical dry forest in Colombia. Knowing diversity in a threatened ecosystem.

Objetivo. Dado que el Bioma Bosque seco tropical (Bs-T) en Colombia está en peligro y por ende puede desaparecer, se da conocer por primera vez una lista de las especies de mariposas (Lepidoptera: Hesperioidea-Papilionoidae) para Colombia, se indican los vacíos de información existentes en algunas regiones y se proponen algunas especies típicas del Bs-T. Metodología. A partir de una revisión de literatura, salidas de campo, consulta de colecciones biológicas y ayuda de algunos especialistas se genera una lista taxonómica de mariposas para este ecosistema. Resultados. Un total de 2222 registros y 1825 individuos fueron revisados que corresponden a 662 especies, donde la familia Nymphalidae presento 274 especies, seguida por Hesperiidae con 183, Riodinidae 69, Pieridae 52, Lycaenidae 73 y Papilionidae con 21 especies. Además se proponen y figuran 15 especies de mariposas características de este tipo de ecosistema. Alcance. Se aporta conocimiento sobre la diversidad mariposas para un ecosistema en estado crítico como lo es el Bs-T, al igual que se genera una aproximación sobre su riqueza que permite proponer estrategias de conservación para el ecosistema.Objective. To present for the first time the list of butterfly species (Lepidoptera: HesperioideaPapilionoidae) for the Tropical Dry Forest (Bs-T) of Colombia, the information gaps in some regions are indicated and some are proposed typical species of Bs-T. Methodology. Based on a review of literature, field trips, consultation of biological collections and the help of some specialists, a taxonomic list of butterflies for this ecosystem is proposed. Results. A total of 2222 records and 1825 individuals were reviewed corresponding to 662 species, where the Nymphalidae family presented 274 species, followed by Hesperiidae with 183, Riodinidae 69, Pieridae 52, Lycaenidae 73 and Papilionidae with 21 species. In addition, 15 species of butterflies characteristic of this type of ecosystem are proposed and listed. Scope. Knowledge is provided about the diversity of butterflies for an ecosystem in critical condition such as Bs-T, as well as an approximation of its wealth that allows to propose conservation strategies for the ecosystem

Inhibition of HIV-1 gene expression by Sam68ΔC: multiple targets but a common mechanism?

Two recent publications have explored the mechanisms by which a mutant of the host protein Sam68 blocks HIV-1 structural protein synthesis and expands its activity to encompass Nef. Although the two studies propose different mechanisms for the responses observed, it is possible that a common activity is responsible. Understanding how this Sam68 mutant discriminates among the multiple viral mRNAs promises to reveal unique properties of HIV-1 RNA metabolism

Local invertibility in Sobolev spaces with applications to nematic elastomers and magnetoelasticity

We define a class of deformations in W^1,p(\u3a9,R^n), p>n 121, with positive Jacobian that do not exhibit cavitation. We characterize that class in terms of the non-negativity of the topological degree and the equality between the distributional determinant and the pointwise determinant of the gradient. Maps in this class are shown to satisfy a property of weak monotonicity, and, as a consequence, they enjoy an extra degree of regularity. We also prove that these deformations are locally invertible; moreover, the neighbourhood of invertibility is stable along a weak convergent sequence in W^1,p, and the sequence of local inverses converges to the local inverse. We use those features to show weak lower semicontinuity of functionals defined in the deformed configuration and functionals involving composition of maps. We apply those results to prove existence of minimizers in some models for nematic elastomers and magnetoelasticity

Evaluacion de la actividad antitumoral de extractos de hojas y tallos de niguito monochaetum multiflorum (bonpl.) naud. (melastomataceae)

Las hojas y tallos de la planta Niguito (Monochaetum multiflorum) (Bonpl.) Naud., se homogenizaron en acetona acuosa al 70%. El homogenizado fue fraccionado secuencialmente por extracción líquido-líquido con Et2O, EtOAc, n-butanol. Para la evaluación de la actividad antitumoral, se utilizaron explantes de discos de zanahoria (Dacus carota) y la bacteria Agrobacterium tumefaciens, responsable de tumoración. Los extractos etéreos de tallos y hojas presentaron los porcentajes de inhibición más altos