2,254 research outputs found
Keypad mobile phones are associated with a significant increased risk of microbial contamination compared to touch screen phones
The use of mobile phones in the clinical environment by healthcare workers has become widespread. Despite evidence that these devices can harbour pathogenic micro-organisms there is little guidance on how to reduce contamination. Recently touchscreen phones with a single flat surface have been introduced. We hypothesise that bacterial contamination of phones used in hospitals will be lower on touchscreen devices compared to keypad devices. Sixty seven mobile phones belonging to health care workers were sampled. The median colony count for touchscreen phones and keypad devices was 0·09 colony forming units (cfu)/cm2 (interquartile range (IQR) 0.05–0·14) and 0·77 cfu/cm2 (IQR range 0·45–3.52) respectively. Colony counts were significantly higher on the keypad phones (Fisher’s exact test p<0.001). Multivariate analysis showed the type of phone (keypad vs. touch screen) was associated with increased colony counts (F-statistic 14.13: p<0.001). Overall, nine (13%) phones grew either meticillin resistant Staphylococcus aureus or vancomycin resistant enterococci. Eight (24%) keypad phones were contaminated with these organisms compared with one touch screen phone (3%). Our data indicate that touchscreen mobile phones are less contaminated than their keypad counterparts, and they are less likely to harbour pathogenic bacteria in the clinical setting
Towards Stirling engine using an optically confined particle subjected to asymmetric temperature profile
The realization of microscopic heat engines has gained a surge of research
interest in statistical physics, soft matter, and biological physics. A typical
microscopic heat engine employs a colloidal particle trapped in a confining
potential, which is modulated in time to mimic the cycle operations. Here, we
use a lanthanide-doped upconverting particle (UCP) suspended in a passive
aqueous bath, which is highly absorptive at 975 nm and converts NIR photons to
visible, as the working substance of the engine. When a single UCP is optically
trapped with a 975 nm laser, it behaves like an active particle by executing
motion subjected to an asymmetric temperature profile along the direction of
propagation of the laser. The strong absorption of 975 nm light by the particle
introduces a temperature gradient and results in significant thermophoretic
diffusion along the temperature gradient. However, the activity of the particle
vanishes when the trapping wavelength is switched to 1064 nm. We carefully
regulate the wavelength-dependent activity of the particle to engineer all four
cycles of a Stirling engine by using a combination of 1064 nm and 975 nm
wavelengths. Since the motion of the particle is stochastic, the work done on
the particle due to the stiffness modulation per cycle is random. We provide
statistical estimation for this work averaged over 5 cycles which can be
extended towards several cycles to make a Stirling engine. Our experiment
proposes a robust set-up to systematically harness temperature which is a
crucial factor behind building microscopic engines.Comment: For published version, see
https://iopscience.iop.org/article/10.1088/1367-2630/acd94e/met
ISIS and NISIS: New bilingual dual-channel speech corpora for robust speaker recognition
It is standard practice to use benchmark datasets for comparing meaningfully the performance of a number of competing speaker identification systems. Generally, such datasets consist of speech recordings from different speakers made at a single point of time, typically in the same language. That is, the training and test sets both consist of speech recorded at the same point of time in the same language over the same recording channel. This is generally not the case in real-life applications. In this paper, we introduce a new database consisting of speech recordings of 105 speakers, made over four sessions, in two languages and simultaneously over two channels. This database provides scope for experimentation regarding loss in efficiency due to possible mismatch in language, channel and recording session. Results of experiments with MFCC-based GMM speaker models are presented to highlight the need of such benchmark datasets for identifying robust speaker identification systems
Momentum-dependent contributions to the gravitational coupling of neutrinos in a medium
When neutrinos travel through a normal matter medium, the electron neutrinos
couple differently to gravity compared to the other neutrinos, due to the
presence of electrons in the medium and the absence of the other charged
leptons. We calculate the momentum-dependent part of the matter-induced
gravitational couplings of the neutrinos under such conditions, which arise at
order , and determine their contribution to the neutrino dispersion
relation in the presence of a gravitational potential .
These new contributions vanish for the muon and tau neutrinos. For electron
neutrinos with momentum , they are of the order of the usual Wolfenstein
term times the factor , for high energy
neutrinos. In environments where the gravitational potential is substantial,
such as those in the vicinity of Active Galactic Nuclei, they could be the
dominant term in the neutrino dispersion relation. They must also be taken into
account in the analysis of possible violations of the Equivalence Principle in
the neutrino sector, in experimental settings involving high energy neutrinos
traveling through a matter background.Comment: Minor corrections in the references; one reference adde
Alteration in haematological and biochemical parameters of Catla catla exposed to sub-lethal concentration of cypermethrin
A 60-day experiment was carried out to study the effect of sub-lethal concentration of cypermethrin (1/10th of LC50) exposure on haematological and biochemical parameters of the Indian major carp, Catla catla fingerlings. Under exposure, the total erythrocyte count, total leucocyte count, haemoglobin content and haematocrit were decreased. All the studied serum parameters viz. total serum protein, albumin, globulin contents and albumin–globulin ratio were significantly decreased in cypermethrin-exposed fishes. A marked increase was recorded in alanine aminotransferase and aspartate aminotransferase activities in liver, whereas lactate dehydrogenase activity of muscle and acetylcholine esterase activity in brain were inhibited in cypermethrin-exposed fish. The membrane transport enzymes (total adenosine triphosphatase, sodium–potassium adenosine triphosphatase and magnesium adenosine triphosphatase) activities were decreased significantly in the gills of C. catla exposed to sub-lethal concentration of cypermethrin. The present study indicates that sub-lethal exposure of C. catla fingerlings to cypermethrin alters the haematological and biochemical parameters
One-loop flavor changing electromagnetic transitions
We discuss the effect of the external fermion masses in the flavor-changing
radiative transitions of a heavy fermion (quark or lepton) to a lighter fermion
at the one-loop level, and point out an often overlooked crucial difference in
the sign of a charge factor between transitions of the down type
and the up type . We give formulas for the
effective vertex in various approximations and the exact formula for and .Comment: LaTeX 16 pages + 4 postscript figures. Misprints corrected, some
Comments adde
One-pot synthesis of multifunctional ZnO nanomaterials: study of superhydrophobicity and UV photosensing property
ZnO nanomaterials are synthesized using one-pot synthesis method. Equimolar solution of Zinc Nitrate hexahydrate (Zn(NO3)(2).6H(2)O) and Hexamethylenetetramine (C6H12N4) is used as a precursor for ZnO formation. Different nanostructures of ZnO are achieved by controlling the pH of the growth solution in the range 2-12 (acidic to alkali). ZnO nanostructures are evaluated for hydrophobic property using static contact angle measurement setup and UV photosensing activity. Surface morphology, structural properties and compositional analysis of ZnO nanostructures are examined by field emission scanning electron microscope (FE-SEM), energy dispersive X-ray analysis (EDX), high-resolution transmission electron microscope (FEG-TEM) and X-ray diffraction (XRD) measurements. Existence of ZnO wurtzite structure is confirmed from XRD study and is analyzed by Rietveld refinement method. Nanomaterials are characterized using Raman spectroscopy which confirms highest oxygen deficiency in ZnO nanorods. The material shows remarkable superhydrophobic and UV photosensing property and hence the name multifunctional. Among all morphologies grown at different pH values, ZnO nanorods show superhydrophobic nature with contact angle more than 170 degrees. Total surface energy value of ZnO nanostructures is calculated using Wendt two-component theory. Different ZnO nanostructures (with variation of pH value) are used to study UV photosensing property. Responsivity and photocurrent show a strong dependence on the morphology of ZnO
Soft Electromagnetic Radiations from Relativistic Heavy Ion Collisions
The production of low mass dileptons and soft photons from thermalized Quark
Gluon Plasma (QGP) and hadronic matter in relativistic heavy ion collisions is
evaluated. A boost invariant longitudinal and cylindrically symmetric
transverse expansion of the systems created in central collision of lead nuclei
at CERN SPS, BNL RHIC, and CERN LHC, and undergoing a first order phase
transition to hadronic matter is considered. A large production of low mass (M<
0.3 GeV) dileptons, and soft photons (p_T< 0.4 GeV) is seen to emanate from the
bremsstrahlung of quarks and pions. We find an increase by a factor of 2--4 in
the low mass dilepton and soft photon yield as we move from SPS to RHIC
energies, and an increase by an order of magnitude as we move from SPS to LHC
energies. Most of the soft radiations are found to originate from pion driven
processes at SPS and RHIC energies, while at the LHC energies the quark and the
pion driven processes contribute by a similar amount. The study of the
transverse mass distribution is seen to provide interesting details of the
evolution. We also find a unique universal behaviour for the ratio of M^2
weighted transverse mass distribution for M= 0.1 GeV to that for M= 0.2 and 0.3
GeV, as a function of M_T, for SPS, RHIC, and LHC energies, in the absence of
transverse expansion of the system. A deviation from this universal behaviour
is seen as a clear indication of the flow.Comment: Revtex fil
Characterizing the Decision Process in Setting Corn and Soybean Seeding Rates
Selecting optimal corn and soybean seeding rates are difficult decisions to make. A survey of Ohio and Michigan farm operators finds that, although generally keen to learn from others, they tend to emphasize their own experience over outside information sources. Soybean growers declare university and extension recommendations as more important than do corn growers. In response to direct queries and in free comments, growers place more emphasis on understanding the agronomic and technological problems at hand than on adjusting to the market environment. Given the decision environment, we argue that these responses are reasonable
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