A Holling-Tanner predator-prey model with strong Allee effect

We analyse a modified Holling-Tanner predator-prey model where the predation functional response is of Holling type II and we incorporate a strong Allee effect associated with the prey species production. The analysis complements results of previous articles by Saez and Gonzalez-Olivares (SIAM J. Appl. Math. 59 1867-1878, 1999) and Arancibia-Ibarra and Gonzalez-Olivares (Proc. CMMSE 2015 130-141, 2015)discussing Holling-Tanner models which incorporate a weak Allee effect. The extended model exhibits rich dynamics and we prove the existence of separatrices in the phase plane separating basins of attraction related to co-existence and extinction of the species. We also show the existence of a homoclinic curve that degenerates to form a limit cycle and discuss numerous potential bifurcations such as saddle-node, Hopf, and Bogadonov-Takens bifurcations

Semiconductor Materials by Ultrasonic Spray Pyrolysis and Their Application in Electronic Devices

Ultrasonic spray pyrolysis is a deposition technique that enables a fine mist of the precursor solution in order to deposit higher-density thin films. This characteristic makes of great potential the use of ultrasonically spray-deposited semiconductors films for low-cost, transparent, flexible and large-area applications. In this chapter, low-temperature deposition and characterization of ultrasonically spray-deposited zinc oxide (ZnO) films are presented. The ZnO films deposited by ultrasonic spray pyrolysis at 200°C were characterized by optical transmittance, photoluminescence spectroscopy, X-ray diffraction and Fourier transform infrared spectroscopy. The study of low-temperature annealing of ZnO films is also presented. Moreover, the characterization of aluminum-doped ZnO films deposited by ultrasonic spray pyrolysis at 200°C is presented. Finally, applications of these ultrasonic spray-deposited films in electronic devices are presented

Commencement of flash glucose monitoring is associated with a decreased rate of depressive disorders among persons with diabetes (FLARE-NL7)

INTRODUCTION: Depressive disorders are more common among persons with diabetes, as compared with persons without diabetes. The burden of glucose management is known to associate with depressive symptoms. This study aims to assess the effects of commencement of FreeStyle Libre flash glucose monitoring (FSL-FGM) on the mental health status of persons with diabetes. RESEARCH DESIGN AND METHODS: Post-hoc analysis of data from a 1-year prospective nationwide FSL-FGM registry. Participants who used FSL-FGM for 12 months and completed the 12-Item Short Form Health Survey version 2 (SF-12v2) questionnaires at baseline, 6 and 12 months were included. An SF-12v2 Mental Component Score (MCS) of ≤45 was used as a cut-off to discriminate between persons with and without a depressive disorder. RESULTS: A total of 674 patients were included with a mean age of 48.2 (±15.8) years, 51.2% men, 78.2% type 1 diabetes and baseline HbA1c 62.8 (±13.4) mmol/mol (7.9±1.2%). At baseline, 235 (34.9%) persons had an SF-12 MCS ≤45 while after 6 and 12 months these numbers decreased: 202 (30.0%, p<0.01) and 173 (25.7%, p<0.01). Overall, MCS improved from 48.5 at baseline to 50.7 after 6 months and 51.3 after 12 months. In multivariable regression analysis, age and MCS at baseline were associated with improvement of MCS after 12 months of FSL-FGM use. CONCLUSIONS: This analysis suggests that use of FSL-FGM is associated with a decreased rate of depressive disorders among persons with diabetes. Future studies are needed to corroborate these findings

Detecting explosive-device emplacement at multiple granularities

This paper appeared in the Proceedings of the Military Sensing Society (MSS) National Symposium, Las Vegas, Nevada, U.S., July 2010.We report on experiments with a nonimaging sensor network for detection of suspicious behavior related to pedestrian emplacement of IEDs. Emplacement is the time when detection is the most feasible for IEDs since it almost necessarily must involve some unusual behaviors. Sensors at particularly dangerous locations such as bridges, culverts, road narrowings, and road intersections could provide early warning of such activity. Imaging for surveillance has weaknesses in its susceptibility to occlusion, problems operating at night, sensitivity to angle of view, high processing requirements, and need to invade privacy. Our approach is to use a variety of nonimaging sensors with different modalities to track people. We particularly look for clues as to accelerations since these are often associated with suspicious behavior. Our approach involves preanalyzing terrain for the probability of emplacement of an IED, then combining this with real-time assessment of suspicious behavior obtained from probabilities of location derived from sensor data. We describe some experiments with a prototype sensor network and the promising results obtained.supported by the U.S. National Science Foundation under grant 0729696 of the EXP ProgramApproved for public release; distribution is unlimited

Statistical study of user perception of smart homes during vital signal monitoring with an energy saving algorithm

Sensor networks are deployed in people’s homes to make life easier and more comfortable and secure. They might represent an interesting approach for elderly care as well. This work highlights the benefits of a sensor network implemented in the homes of a group of users between 55 and 75 years old, which encompasses a simple home energy optimization algorithm based on user behavior. We analyze variables related to vital signs to establish users’ comfort and tranquility thresholds. We statistically study the perception of security that users exhibit, differentiating between men and women, examining how it affects the person’s development at home, as well as the reactivity of the sensor algorithm, to optimize its performance. The proposed algorithm is analyzed under certain performance metrics, showing an improvement of 15% over a sensor network under the same conditions. We look at and quantify the usefulness of accurate alerts on each sensor and how it reflects in the users’ perceptions (for men and women separately). This study analyzes a simple, low-cost, and easy-to-implement home-based sensor network optimized with an adaptive energy optimization algorithm to improve the lives of older adults, which is capable of sending alerts of possible accidents or intruders with the highest efficiency

Factores que Influyen la Decision de Outsource Tecnologias de Informacion

Este estudio tiene dos objetivos: Primero, identificar cuáles son los criterios clave de decisión del Outsourcing de Tecnologías de Información (OTI) en las empresas mexicanas. Segundo, identificar las diferencias que existen entre estos factores en las empresas que ya tienen contratados servicios de OTI y las empresas que no lo tienen. Se aplicó un cuestionario a gerentes y directores de 152 empresas en México. Los catalizadores más importantes de la decisión del OTI son: Tener menores costos a los que implica tener un área interna de TI, buscar que la empresa se enfoque a mejorar sus procesos de negocio y mejorar el servicio a sus clientes. Los inhibidores más frecuentes para tomar la decisión de OTI son relacionados a aspectos de seguridad de datos o a perder el nivel de confidencialidad de la empresa, a perder el control sobre sus operaciones y se considera una opción costosa. Los tres servicios de OTI más citados por las empresas son: Desarrollo de proyectos business to business, Help Desk/Call Center y Administración de Redes Remotas

Triglyceride-rich lipoprotein and LDL particle subfractions and their association with incident type 2 diabetes:the PREVEND study

Abstract Background Triglyceride-rich lipoproteins particles (TRLP) and low density lipoprotein particles (LDLP) vary in size. Their association with β-cell function is not well described. We determined associations of TRLP and LDLP subfractions with β-cell function, estimated as HOMA-β, and evaluated their associations with incident T2D in the general population. Methods We included 4818 subjects of the Prevention of Renal and Vascular End-Stage Disease (PREVEND) study without T2D at baseline. TRLP and LDLP subfraction concentrations and their average sizes were measured using the LP4 algorithm of the Vantera nuclear magnetic resonance platform. HOMA-IR was used as measure of insulin resistance. HOMA-β was used as a proxy of β-cell function. Results In subjects without T2D at baseline, very large TRLP, and LDL size were inversely associated with HOMA-β, whereas large TRLP were positively associated with HOMA-β when taking account of HOMA-IR. During a median follow-up of 7.3 years, 263 participants developed T2D. In multivariable-adjusted Cox regression models, higher concentrations of total, very large, large, and very small TRLP (reflecting remnants lipoproteins) and greater TRL size were associated with an increased T2D risk after adjustment for relevant covariates, including age, sex, BMI, HDL-C, HOMA-β, and HOMA-IR. On the contrary, higher concentrations of large LDLP and greater LDL size were associated with a lower risk of developing T2D. Conclusions Specific TRL and LDL particle characteristics are associated with β-cell function taking account of HOMA-IR. Moreover, TRL and LDL particle characteristics are differently associated with incident T2D, even when taking account of HOMA-β and HOMA-IR