The aerodynamic effects of wing rotation and a revised quasi-steady model of flapping flight

We used a dynamically scaled model insect to measure the rotational forces produced by a flapping insect wing. A steadily translating wing was rotated at a range of constant angular velocities, and the resulting aerodynamic forces were measured using a sensor attached to the base of the wing. These instantaneous forces were compared with quasi-steady estimates based on translational force coefficients. Because translational and rotational velocities were constant, the wing inertia was negligible, and any difference between measured forces and estimates based on translational force coefficients could be attributed to the aerodynamic effects of wing rotation. By factoring out the geometry and kinematics of the wings from the rotational forces, we determined rotational force coefficients for a range of angular velocities and different axes of rotation. The measured coefficients were compared with a mathematical model developed for two-dimensional motions in inviscid fluids, which we adapted to the three-dimensional case using blade element theory. As predicted by theory, the rotational coefficient varied linearly with the position of the rotational axis for all angular velocities measured. The coefficient also, however, varied with angular velocity, in contrast to theoretical predictions. Using the measured rotational coefficients, we modified a standard quasi-steady model of insect flight to include rotational forces, translational forces and the added mass inertia. The revised model predicts the time course of force generation for several different patterns of flapping kinematics more accurately than a model based solely on translational force coefficients. By subtracting the improved quasi-steady estimates from the measured forces, we isolated the aerodynamic forces due to wake capture

Isolated elliptical galaxies in the local Universe

We have studied a sample of 89 very isolated, elliptical galaxies at z < 0.08 and compared their properties with elliptical galaxies located in a high-density environment such as the Coma supercluster. Our aim is to probe the role of environment on the morphological transformation and quenching of elliptical galaxies as a function of mass. In addition, we elucidate the nature of a particular set of blue and star-forming isolated ellipticals identified here. We study physical properties of ellipticals such as color, specific star formation rate, galaxy size, and stellar age, as a function of stellar mass and environment based on SDSS data. We analyze the blue star-forming isolated ellipticals in more detail, through photometric characterization using GALFIT, and infer their star formation history using STARLIGHT. Among the isolated ellipticals ~ 20% are blue, 8% are star forming, and ~ 10% are recently quenched, while among the Coma ellipticals ~ 8% are blue and just <= 1% are star forming or recently quenched. There are four isolated galaxies (~ 4.5%) that are blue and star forming at the same time. These galaxies, with masses between 7 x 10^9 and 2 x 10^10 h-2 M_sun, are also the youngest galaxies with light-weighted stellar ages <= 1 Gyr and exhibit bluer colors toward the galaxy center. Around 30-60% of their present-day luminosity, but only < 5% of their present-day mass, is due to star formation in the last 1 Gyr. The processes of morphological transformation and quenching seem to be in general independent of environment since most of elliptical galaxies are 'red and dead', although the transition to the red sequence should be faster for isolated ellipticals. In some cases, the isolated environment seems to propitiate the rejuvenation of ellipticals by recent (< 1 Gyr) cold gas accretion.Comment: 23 pages, 15 figures (16 pages and 9 figures without appendices). A&A, in pres

Phase diagrams of period-4 spin chains consisting of three kinds of spins

We study a period-4 antiferromagnetic mixed quantum spin chain consisting of three kinds of spins. When the ground state is singlet, the spin magnitudes in a unit cell are arrayed as (s-t, s, s+t, s) with integer or half-odd integer s and t (0 <= t < s). The spin Hamiltonian is mapped onto a nonlinear sigma model (NLSM) in a previously developed method. The resultant NLSM includes only two independent parameters originating from four exchange constants for fixed s and t. The topological angle in the NLSM determines the gapless phase boundaries between disordered phases in the parameter space. The phase diagrams for various s and t shows rich structures. We systematically explain the phases in the singlet-cluster-solid picture.Comment: 8 pages (16 figures included

Drug utilization study in ophthalmology in OPD patients at a tertiary care teaching hospital

Background: Drug therapy is a major component of patient care management in health care settings. Irrational and inappropriate use of drugs in health care system observed globally is being a major concern. In the field of ophthalmology, there have been many drug developments and different classes of drugs with combinational products are available in ophthalmology for the treatment of ophthalmic diseases. Periodic prescription analysis in the form of drug utilization study can improve the quality of prescription and curb the menace of irrational prescribing. Aim and objectives were to study the prescribing pattern and drug utilization trends in Ophthalmology outpatient department at a tertiary care hospital in Navi Mumbai.Methods: A cross-sectional, observational study was conducted over a period of six months in Ophthalmology department of a tertiary care teaching hospital, Navi-Mumbai. A total of 103 adult patients visiting Ophthalmology OPD for curative symptoms were included and their prescriptions were analyzed with WHO prescribing indicators and additional indices.Results: Analysis showed that the average number of drugs per prescription was 1.9. Percentage of drugs prescribed by brand was 100 % versus generic 0 %. Percentage of drugs prescribed from National Essential drug list (NEDL) was 53%. The percentage of encounters with antibiotics was 30.6%. The commonest prescribed drugs were ocular lubricants followed by antibiotics. Eye drops were the commonest prescribed dosage form.Conclusions: Ocular lubricants and antibiotics dominated the prescribing pattern in this study with restraint on polypharmacy, but showed ample scope for improvement in encouraging the ophthalmologist to prescribe generic and selection of essential drugs

Towards integrated surveillance of zoonoses : spatiotemporal joint modeling of rodent population data and human tularemia cases in Finland

Abstract Background There are an increasing number of geo-coded information streams available which could improve public health surveillance accuracy and efficiency when properly integrated. Specifically, for zoonotic diseases, knowledge of spatial and temporal patterns of animal host distribution can be used to raise awareness of human risk and enhance early prediction accuracy of human incidence. Methods To this end, we develop a spatiotemporal joint modeling framework to integrate human case data and animal host data to offer a modeling alternative for combining multiple surveillance data streams in a novel way. A case study is provided of spatiotemporal modeling of human tularemia incidence and rodent population data from Finnish health care districts during years 1995–2012. Results Spatial and temporal information of rodent abundance was shown to be useful in predicting human cases and in improving tularemia risk estimates in 40 and 75% of health care districts, respectively. The human relative risk estimates’ standard deviation with rodent’s information incorporated are smaller than those from the model that has only human incidence. Conclusions These results support the integration of rodent population variables to reduce the uncertainty of tularemia risk estimates. However, more information on several covariates such as environmental, behavioral, and socio-economic factors can be investigated further to deeper understand the zoonotic relationship

Central nervous system infection following vertical transmission of Coxsackievirus B4 in mice

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Coxsackie B viruses (CV-B) are important pathogens associated with several central nervous system (CNS) disorders. CV-B are mainly transmitted by the faecal-oral route, but there is also evidence for vertical transmission. The outcome of in utero CV-B infections on offspring's CNS is poorly explored. The aim of this study was to investigate vertical transmission of CV-B to the CNS. For this purpose, pregnant Swiss albino mice were intraperitoneally inoculated with CV-B4 E2 at gestational days 10G or 17G. Different CNS compartments were collected and analyzed for virus infection and histopathological changes. Using plaque assays, we demonstrated CV-B4 E2 vertical transmission to offspring's CNS. Viral RNA persisted in the CNS up to 60 days after birth, as evidenced by a sensitive semi-nested(sn) reverse transcripton(RT)-PCR method. This was despite infectious particles becoming undetectable at later time points. Persistence was associated with inflammatory lesions, lymphocyte infiltration and viral dsRNA detected by immunohistochemistry. Offspring born to dams mock- or virus-infected at day 17G were challenged by the same virus at day 21 after birth (-+ and ++ groups, respectively). Sn-RT-PCR and histology results compared between both ++ and -+ groups, show that in utero infection did not enhance CNS infection during challenge of the offspring with the same virus.This work was supported by Ministère de l’Enseignement Supérieur et de la Recherche Scientifique, (LR99ES27), Tunisia, and Ministère de l’Education Nationale de la Recherche et de la Technologie, Université Lille 2 CHRU Lille (UPRES EA3610), France. Financial support for S.J.R has come from the European Commission 7th Framework Programme PEVNET [FP7/2007-2013] under grant agreement number 261441 and a Juvenile Diabetes Research Foundation (JDRF) Career Development Award (5-CDA-2014-221-A-N). Habib JMII was supported by grants from Ministère de l’Enseignement Supérieur et de la Recherche Scientifique

A Comparison of the Effect of Ondansetron and Propofol on Intrathecal Opioid-Induced itch in Elective Cesarean Section

BACKGROUND AND OBJECTIVE: Itch is one of the most common and uncomfortable side effects of neuraxial anesthesia. Its incidence is higher especially in cesarean section. The aim of this study was to compare the effect of ondansetron and propofol at doses lower than the hypnotic dose on the treatment of itch induced by intrathecal fentanyl in cesarean section. METHODS: In this prospective study, 90 patients with American Society of Anesthesiologists (ASA) class I and class II with an average age of 30 years and first time cesarean section underwent intra-spinal anesthesia with 25 μg fentanyl and 10 mg bupivacaine 0.5%. Women were randomly divided into two groups of 45. One group received 4 mg ondansetron and another group received 10 mg propofol at first and then 10 μg / kg / min through infusion. The incidence and severity of itch were recorded on the basis of the visual scoring system during operation and during recovery. FINDINGS:The highest incidence of itch was 30 to 60 minutes after injection. The incidence of itch during surgery was 2.22% and 7.26%, and during recovery was 7.6% and 8.8%, in the ondansetron and propofol groups, respectively (p=0.5, p=0.4). The mean itch severity scores during surgery were 1.85±0.69 and 1.66±0.81, and during the recovery were 1.33±0.57 and 1.25±0.5, in the ondansetron and propofol groups, respectively (p=0.65) (p=0.84). CONCLUSION: Based on the results of this study, ondansetron and propofol at doses lower than the hypnotic dose were well tolerated. Considering the effect of both drugs on the treatment of itch caused by intrathecal fentanyl, both of them can be used clinicall

Triplet correlations in two-dimensional colloidal model liquids

Three-body distribution functions in classical fluids have been theoretically investigated many times, but have never been measured directly. We present experimental three-point correlation functions that are computed from particle configurations measured by means of video-microscopy in two types of quasi-two-dimensional colloidal model fluids: a system of charged colloidal particles and a system of paramagnetic colloids. In the first system the particles interact via a Yukawa potential, in the second via a potential $\Gamma/r^{3}$. We find for both systems very similar results: on increasing the coupling between the particles one observes the gradual formation of a crystal-like local order due to triplet correlations, even though the system is still deep inside the fluid phase. These are mainly packing effects as is evident from the close resemblance between the results for the two systems having completely different pair-interaction potentials.Comment: many pages, 8 figures, contribution to the special issue in J.Phys. Cond. Mat. of the CECAM meeting in LYON ''Many-body....'

Flapping and Flexible Wing Aerodynamics of Low Reynolds Number Flight Vehicles

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76905/1/AIAA-2006-503-331.pd

Wireless Stimulation of Antennal Muscles in Freely Flying Hawkmoths Leads to Flight Path Changes

Insect antennae are sensory organs involved in a variety of behaviors, sensing many different stimulus modalities. As mechanosensors, they are crucial for flight control in the hawkmoth Manduca sexta. One of their roles is to mediate compensatory reflexes of the abdomen in response to rotations of the body in the pitch axis. Abdominal motions, in turn, are a component of the steering mechanism for flying insects. Using a radio controlled, programmable, miniature stimulator, we show that ultra-low-current electrical stimulation of antennal muscles in freely-flying hawkmoths leads to repeatable, transient changes in the animals' pitch angle, as well as less predictable changes in flight speed and flight altitude. We postulate that by deflecting the antennae we indirectly stimulate mechanoreceptors at the base, which drive compensatory reflexes leading to changes in pitch attitude.United States. Defense Advanced Research Projects Agenc