Phase and frequency entrainment in locally coupled phase oscillators with repulsive interactions

Recent experiments in one and two-dimensional microfluidic arrays of droplets containing Belousov -Zhabotinsky reactants show a rich variety of spatial patterns [J. Phys. Chem. Lett. 1, 1241-1246 (2010)]. The dominant coupling between these droplets is inhibitory. Motivated by this experimental system, we study repulsively coupled Kuramoto oscillators with nearest neighbor interactions, on a linear chain as well as a ring in one dimension, and on a triangular lattice in two dimensions. In one dimension, we show using linear stability analysis as well as numerical study, that the stable phase patterns depend on the geometry of the lattice. We show that a transition to the ordered state does not exist in the thermodynamic limit. In two dimensions, we show that the geometry of the lattice constrains the phase difference between two neighbouring oscillators to 120 degrees. We report the existence of domains with either clockwise or anti-clockwise helicity, leading to defects in the lattice. We study the time dependence of these domains and show that at large coupling strengths, the domains freeze due to frequency synchronization. Signatures of the above phenomena can be seen in the spatial correlation functions.Comment: 9 pages, 12 figure

The Mn site in Mn-doped Ga-As nanowires: an EXAFS study

We present an EXAFS study of the Mn atomic environment in Mn-doped GaAs nanowires. Mn doping has been obtained either via the diffusion of the Mn used as seed for the nanowire growth or by providing Mn during the growth of Au-induced wires. As a general finding, we observe that Mn forms chemical bonds with As but is not incorporated in a substitutional site. In Mn-induced GaAs wires, Mn is mostly found bonded to As in a rather disordered environment and with a stretched bond length, reminiscent of that exhibited by MnAs phases. In Au-seeded nanowires, along with stretched Mn-As coordination we have found the presence of Mn in a Mn-Au intermetallic compound.Comment: This is an author-created, un-copyedited version of an article accepted for publication in Semiconductor Science and Technology. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The definitive publisher-authenticated version is available online at doi:10.1088/0268-1242/27/8/08500

A Study on Microbiological Profile of Vaginitis and Its Association with Urinary Tract Infection during Pregnancy in a Tertiary Care Hospital

INTRODUCTION: Infectious vaginitis which includes bacterial vaginosis (BV), vulvovaginal candidiasis (VVC) and trichomoniasis are common disorders seen in women. Both vaginitis and urinary tract infection (UTI) during pregnancy have risk to lives of both the mother and the fetus. AIM OF THE STUDY: To identify common causes of infectious vaginitis in pregnancy and to determine the risk of urinary tract infections in pregnant women with bacterial vaginosis. METHODOLOGY: Cross sectional descriptive study was done among 200 pregnant patients attending Institute of obstetrics and gynaecology, Egmore. Study period was from March 2017 to February 2018. Duplicate High Vaginal Swab and urine sample were collected from each patient. BV was diagnosed using Amsel’s criteria and Nugent’s scoring. VVC was determined by culture on Sabouraud Dextrose Agar and Candida species were identified by sugar fermentation and assimilation test. Trichomoniasis was detected by observing motile trophozoites under microscope. Diagnosis of UTI was made when there were at least 105 colony forming units/ml of urine. RESULTS: Out of 200 patients, 65 were positive for infectious vaginitis and 32 had UTI. Among 65 infected patients, BV and VVC were found in 42 (64.6%) and 23 (35.4%) respectively. BV associated with UTI was seen in 35.7% of the patients. The association between BV and UTI was found to be statistically significant (p < 0.05). CONCLUSION: Hence, BV was the most common vaginitis among pregnant women and women with BV are at increased risk for UTIs. We recommend that all pregnant women during antenatal check up should be screened for the presence of BV and UTI

Phylogenetic analysis of Artemisia L. (Asteraceae) based on micromorphological traits of pollen grains

The phylogenetic relationships within the genus Artemisia have been very controversial. In order to recognize the systematic inference of pollen grains in this genus, the micromorphological characteristics of pollens from 22 taxa were examined by means of light microscopy (LM) and scanningelectron microscopy (SEM). A phylogenetic analysis of Artemisia based on 9 micromorphological characters of pollens was conducted using Wagner parsimony method. In the resulting phylogenetic tree, relationships among different Artemisia species are shown. This study also presents thephylogenetic associations among 4 sections within the genus Artemisia. The reunion of genus Seriphidum with Artemisia was also confirmed

Characterization of Environmental Levels of Pesticide Residues in Household Air and Dust Samples near a Bioenergy Plant Using Treated Seed as Feedstock

Exposure to neonicotinoid insecticides is associated with adverse human health outcomes. There is environmental contamination in Saunders County, Nebraska, due to the accumulation of fungicides and insecticides from a now-closed ethanol plant using seed corn as stock. A pilot study quantified environmental contamination in nearby houses from residual pesticides by measuring dust and air (indoor/outdoor) concentrations of neonicotinoids and fungicides at the study site (households within two miles of the plant) and control towns (20–30 miles away). Air (SASS® 2300 Wetted-Wall Air Sampler) and surface dust (GHOST wipes with 4 × 4-inch template) samples were collected from eleven study households and six controls. Targeted analysis quantified 13 neonicotinoids, their transformation products and seven fungicides. Sample extracts were concentrated using solid phase extraction (SPE) cartridges, eluted with methanol and evaporated. Residues were redissolved in methanol–water (1:4) prior to analysis, with an Acquity H-Class ultraperformance liquid chromatograph (UPLC) and a Xevo triple quadrupole mass spectrometer. We compared differences across chemicals in air and surface dust samples at the study and control sites by dichotomizing concentrations above or below the detection limit, using Fisher’s exact test. A relatively higher detection frequency was observed for clothianidin and thiamethoxam at the study site for the surface dust samples, similarly for thiamethoxam in the air samples. Our results suggest airborne contamination (neonicotinoids and fungicides) from the ethanol facility at houses near the pesticide contamination

Blockchain-based DDoS attack mitigation protocol for device-to-device interaction in smart homes

Smart home devices are vulnerable to a variety of attacks. The matter gets more complicated when a number of devices collaborate to launch a colluding attack (e.g. Distributed-Denial-of-Service (DDoS)) in a network (e.g., Smart home). To handle these attacks, most studies have hitherto proposed authentication protocols that cannot necessarily be implemented in devices, especially during Device-to-Device (D2D) interactions. Tapping into the potential of Ethereum blockchain and smart contracts, this work proposes a lightweight authentication mechanism that enables safe D2D interactions in a smart home. The Ethereum blockchain enables the implementation of a decentralized prototype as well as a peer-to-peer distributed ledger system. The work also uses a single server queuing system model and the authentication mechanism to curtail DDoS attacks by controlling the number of service requests in the system. The simulation was conducted twenty times, each with varying number of devices chosen at random (ranging from 1 to 30). Each requester device sends an arbitrary request with a unique resource requirement at a time. This is done to measure the system’s consistency across a variety of device capabilities. The experimental results show that the proposed protocol not only prevents colluding attacks, but also outperforms the benchmark protocols in terms of computational cost, message processing, and response time

Effect of Single and Mixed Surfactants on Antioxidant Activity of Bio-Active Molecules

Surfactants have unique physico-chemical properties as a result of their amphiphillic molecular structure and are fundamental to life and living bodies.1 Most of amphiphiles display very important phenomena such as surface activity, wetting adsorption and micelle formation with the resultant functions like solubilization, emulsification, dispersion, drug delivery, ion transport etc.2,3 Micelles are colloidal particles with the size in the nanometre range, into which many amphiphillic molecules self assemble spontaneously.4 They are versatile products and have found application in emulsion polymerization,5,6 enhanced oil recovery,7 biomedical materials,8 and biomemitism.9 Surfactant mixtures have become more interesting than single surfactant solutions due to their wide technological applications and their molecular interactions on complex supramolecular systems.10 The interactions between water soluble polymers and surfactants are of considerable interest from an industrial point of view as well as because they mimic protein membrane interactions.11 The use of aqueous miceller media in kinetic studies is rapidly increasing with the aim to replace the conventional organic solvent based syntheses by micelle based syntheses, which not only provides a greater control over stereoselectivity but is environment friendly as well.12,1

Choroidal vascularity map in unilateral central serous chorioretinopathy: A comparison with fellow and healthy eyes

Background: To map the choroidal vascularity index and compare two eyes in patients with unilateral central serous chorioretinopathy (CSCR). Methods: This was a retrospective, observa-tional study performed in patients with unilateral CSCR. Choroidal thickness (CT) and Choroidal vascularity index (CVI) were measured and mapped in various zones according to the early treatment diabetic retinopathy (ETDRS) grid. Results: A total of 20 CSCR patients (20 study and 20 fellow eyes) were included in the study. Outer nasal region CT was seen to be significantly lower than central CT (p = 0.042) and inner nasal CT (p = 0.007); outer ring CT was significantly less than central (p = 0.04) and inner ring (p = 0.01) CT in CSCR eyes. On potting all the CVI values against the corresponding CT values, a positive correlation was seen in CSCR eyes (r = 0.54, p &lt; 0.01), which was slightly weaker in fellow eyes (r = 0.3, p &lt; 0.01) and a negative correlation was seen in healthy eyes (r = −0.262, p &lt; 0.01). Conclusions: Correlation between CVI and CT was altered in CSCR eyes as compared to fellow and normal eyes with increasing CVI towards the center of the macula and superiorly in CSCR eyes

Direct measurement of the mass difference between top and antitop quarks

We present a direct measurement of the mass difference between top and antitop quarks (dm) in lepton+jets top-antitop final states using the "matrix element" method. The purity of the lepton+jets sample is enhanced for top-antitop events by identifying at least one of the jet as originating from a b quark. The analyzed data correspond to 3.6 fb-1 of proton-antiproton collisions at 1.96 TeV acquired by D0 in Run II of the Fermilab Tevatron Collider. The combination of the e+jets and mu+jets channels yields dm = 0.8 +/- 1.8 (stat) +/- 0.5 (syst) GeV, which is in agreement with the standard model expectation of no mass difference.Comment: submitted to Phys. Rev.