Decoding the biomechanics of flight-tone based acoustic communication in mosquitoes

The aerial courtship dance of mosquitoes involves controlled variations in the frequency and intensity of flight-tones, with concurrent changes in flight speed and direction. This behavior enables detection of conspecifics, leading to competitive flight and acoustic displays of fitness, with successful copulation under the right circumstances. However, despite >150 years of research, it is not clear how the 6-D soundscape (3D space, time, intensity, and frequency) generated by flying mosquitoes is actively modified during courtship. Also, not known are the energetic costs of this courtship behavior, nor the degree to which exogenous sounds can alter and even disrupt courtship. In the current phase of the project, we integrate computational biomechanics and acoustics with biological assays and measurement of sensory-controlled behaviors, to generate unprecedented data and provide insights into courtship-associated acoustic communication in mosquitoes. We have developed a computational tool to predict the aerodynamics, energetics and soundscape mapping of mosquito flight-tones. Wing kinematics extracted from high-speed images of flying mosquitoes have provided input for simulations. The current focus is on comparison of simultaneous measurements of wing-kinematics, flight-tone intensity and directivity from tethered and free-flying mosquitoes, male and female alone or in pairs. Analysis of the computational and experimental results will provide insights into the mechanisms of flight control and scaling of energetic costs, and efficiency of flight-tone generation. 6D sound maps of flight-tones for flying mosquitoes are being constructed to enable quantitative analyses of acoustic communication between mosquitoes during each stage of mating: from the onset of male mating-swarms to the interactions within male-female dyads. The success of this novel approach could be transformative for many pest species of flying insects that employ similar modes of mating communication; our results could form the scientific foundation for exploitation of sound-stimuli that we now know control the success/failure of mating for each generation of mosquitoes. Such technologies have the potential to significantly reduce vector populations and lead to environmentally friendly strategies by diminishing mating success in vectors of malaria, Zika fever and other devastating mosquito-borne diseases

3D audio-visual recordings of mosquito wings for aeroacoustic simulation

Mosquito acoustic communication is studied for its singular and poorly-known in-flight hearing mechanism, for its efficiency in mechanical-to-acoustical power transduction, as well as for being the deadliest disease vector. A combined computational and experimental methods to predict and extract the wing-tone sound from individual tethered or free-flying mosquitoes was developed. This paper describes the experimental methods and gives some preliminary results of the simulations. Simultaneous slow-motion images (20k fps) and 3D-sound of Culex quinquefasciatus mosquitoes were recorded. The sound map around the mosquitoes was recorded in one or two planes with a rotating array of 12-microphones. Back-illuminated mosquito-wings allowed to extract 11 vein-crossing locations on each high-speed camera image over 3-4 wing-beat periods to generate 3D deformations of the wing. Simultaneous 3D sound data recorded by microphone arrays were post-processed by using the physics-based independent component analysis to filter out the noise and generate a 3D sound map. The simulated wing-tone sound pattern generated from the aeroacoustic simulation agrees well with the original recording in the experiment using the microphone array. The methods we developed will allow us to investigate the wing-tone soundscape of individual mosquitoes during the courtship and mate-chasing

Decoding the biomechanics of flight-tone based acoustic communication in mosquitoes

The aerial courtship dance of mosquitoes involves controlled variations in the wingbeat frequency (WBF) and intensity of flight-tones, with concurrent changes in flight speed and direction. This behavior enables acoustic detection of conspecifics in mating swarms, leading to a competitive chase between the female and the male copulation. However, despite >150 years of research, it is not clear how the 6-D soundscape (3D space, time, intensity, and WBF) generated by flying mosquitoes is actively modified during courtship. A novel experimental setup has been installed to record free- flying mosquitoes during mating behavior (figure 1). This includes 3 high-speed cameras (resolution: 22500 frames/second) that can record micrometer-level deformations in the wing. Simultaneously, an array of 12 microphones surrounds the swarming area to capture sound directivity. The wing kinematics for each mosquito were digitally reconstructed by tracking the deformation of vein crossings. They were then fed to a state-of-the-art computational biomechanics suite, which then provided spatio-temporal predictions of aerodynamic & aeroacoustic loads. Our acoustic analysis confirms that wingtones are highly directional with a symmetrical bimodal shape (figure 2). A harmonic decomposition of the sound pressure reveals that there would be some optimal locations for the male (horizontal plane) to hear the chased female. We further learn that mosquitoes generate max lift during upstroke as the wing pronates. The existence of force peaks when wing rotation changes signs reflects an increased dependece on aerodynamic mechanisms like rotational circulation and wake capture. This is confirmed by instantaneous flow structures (figure 3). A scaling analysis permits the identification of dynamically relevant parameters, e.g., the wing rotation factor. The success of this novel approach could be transformative for methods for population control of many pest species of flying insects that employ similar modes of mating communication; our results help understand WBF related observations in mating swarms and potentially could form the scientific foundation for exploitation of sound-stimuli by diminishing mating success in vectors of malaria, Zika & other mosquito-borne diseases

Developing a medical device-grade T2 phantom optimized for myocardial T2 mapping by cardiovascular magnetic resonance

INTRODUCTION: A long T2 relaxation time can reflect oedema, and myocardial inflammation when combined with increased plasma troponin levels. Cardiovascular magnetic resonance (CMR) T2 mapping therefore has potential to provide a key diagnostic and prognostic biomarkers. However, T2 varies by scanner, software, and sequence, highlighting the need for standardization and for a quality assurance system for T2 mapping in CMR. AIM: To fabricate and assess a phantom dedicated to the quality assurance of T2 mapping in CMR. METHOD: A T2 mapping phantom was manufactured to contain 9 T1 and T2 (T1|T2) tubes to mimic clinically relevant native and post-contrast T2 in myocardium across the health to inflammation spectrum (i.e., 43-74 ms) and across both field strengths (1.5 and 3 T). We evaluated the phantom's structural integrity, B0 and B1 uniformity using field maps, and temperature dependence. Baseline reference T1|T2 were measured using inversion recovery gradient echo and single-echo spin echo (SE) sequences respectively, both with long repetition times (10 s). Long-term reproducibility of T1|T2 was determined by repeated T1|T2 mapping of the phantom at baseline and at 12 months. RESULTS: The phantom embodies 9 internal agarose-containing T1|T2 tubes doped with nickel di-chloride (NiCl2) as the paramagnetic relaxation modifier to cover the clinically relevant spectrum of myocardial T2. The tubes are surrounded by an agarose-gel matrix which is doped with NiCl2 and packed with high-density polyethylene (HDPE) beads. All tubes at both field strengths, showed measurement errors up to ≤ 7.2 ms [< 14.7%] for estimated T2 by balanced steady-state free precession T2 mapping compared to reference SE T2 with the exception of the post-contrast tube of ultra-low T1 where the deviance was up to 16 ms [40.0%]. At 12 months, the phantom remained free of air bubbles, susceptibility, and off-resonance artifacts. The inclusion of HDPE beads effectively flattened the B0 and B1 magnetic fields in the imaged slice. Independent temperature dependency experiments over the 13-38 °C range confirmed the greater stability of shorter vs longer T1|T2 tubes. Excellent long-term (12-month) reproducibility of measured T1|T2 was demonstrated across both field strengths (all coefficients of variation < 1.38%). CONCLUSION: The T2 mapping phantom demonstrates excellent structural integrity, B0 and B1 uniformity, and reproducibility of its internal tube T1|T2 out to 1 year. This device may now be mass-produced to support the quality assurance of T2 mapping in CMR

The effects of cocoa supplementation, caloric restriction, and regular exercise, on oxidative stress markers of brain and memory in the rat model

The effects of treadmill running (8 weeks, 5 times/week, 1h/day at 27 m/min), caloric restriction, and cocoa supplementation on brain function and oxidative stress markers were tested. The Morris maze test was used to appraise rat memory. Regular exercise significantly improved spatial learning performance. The level of oxidative stress was measured by the concentration of carbonylated proteins. The free radical concentration increased in brain of the training groups but not the controls. The content of reactive carbonyl derivates did not change with exercise, suggesting that the increased production of reactive oxygen species (ROS) were well tolerated in this experimental model. Caloric restriction (CR) decreased the accumulation of free radicals in the frontal lobe. The protein content of brain-derived neutrophic factors (BDNFs) was evaluated and changes did not occur either with exercise or cocoa supplementation treatments. These data did not show significant effects of the administration of cocoa (2% w/w) on the concentration of ROS, BDNF or on spatial memory. Conversely, exercise and CR can play a role in ROS generation and brain function

Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good

Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis