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The transition to turbulence in pipe flow proceeds through several distinct stages, eventually producing aggressively expanding regions of fluctuations, ‘slugs’, surrounded by laminar flow. By examining mean-velocity profiles, fluctuating-velocity profiles and Reynolds stress profiles, the seminal study of Wygnanski & Champagne (J. Fluid Mech., vol. 59 (2), 1973, 281–335) concluded that the flow inside slugs is ‘identical’ to fully turbulent flow. Although this conclusion is widely accepted, upon closer examination of their analysis, we find that their data cannot be used to substantiate this conclusion. We resolve this conflict via new experiments and simulations wherein we pair slugs and fully turbulent flow at the same value of Reynolds number (
). We conclude that the flow inside a slug is indeed indistinguishable from a fully turbulent flow but only when the two flows share the same value of
. Our work highlights the rich
-dependence of transitional pipe flows.
Pikeperch (Sander lucioperca) is a highly valuable fish in Europe. However, development of aquaculture of pikeperch is highly limited due to seasonality of production. This can be overcome by the controlled reproduction of domesticated fish. The first steps of domestication process may induce changes at anatomical, physiological and molecular levels, thereby affecting a variety of biological functions. While there is abundant literature on their effects on stress and growth for example, these effects on reproduction received limited attention notably in pikeperch, a promising candidate for the development of aquaculture. To answer the question of this life-history effect on pikeperch’s reproduction, we compared two groups (weight: 1 kg) originated from Czech Republic and with the same domestication level (F0). The first group was a recirculating aquatic system cultured one (2 years, previously fed with artificial diet, never exposed to natural changes in temperature/photoperiod conditions) and the second one was a pond cultured group (3 to 4 years, bred under natural feeding and temperature/photoperiod). The wild group successfully spawned, while the farmed one did not spawn at all. During the program, gonadosomatic indexes of both males and females were significantly higher for the wild fish, as well as the sexual steroids. Gene expression analysis revealed significantly lower LH transcript levels at the pituitary level for the farmed females and lower FSH transcript levels at the pituitary level for the males. In conclusion this study showed that the previous rearing conditions (e.g. culture system, age, diet, etc.) alter the further progress of gametogenesis and the reproductive performances in response to controlled photothermal program for both sexes in pikeperch.
Populations of the White-rumped Vulture Gyps bengalensis, Indian Vulture G. indicus and Slender-billed Vulture G. tenuirostris declined rapidly during the mid-1990s all over their ranges in the Indian subcontinent because of poisoning due to veterinary use of the non-steroidal anti-inflammatory drug diclofenac. This paper reports results from the latest in a series of road transect surveys conducted across northern, central, western and north-eastern India since the early 1990s. Results from the seven comparable surveys now available were analysed to estimate recent population trends. Populations of all three species of vulture remained at a low level. The previously rapid decline of White-rumped Vulture has slowed and may have reversed since the ban on veterinary use of diclofenac in India in 2006. A few thousand of this species, possibly up to the low tens of thousands, remained in India in 2015. The population of Indian Vulture continued to decline, though probably at a much slower rate than in the 1990s. This remains the most numerous of the three species in India with about 12,000 individuals in 2015 and a confidence interval ranging from a few thousands to a few tens of thousands. The trend in the rarest species, Slender-billed Vulture, which probably numbers not much more than 1,000 individuals in India, cannot be determined reliably.
Rotavirus (RV) infection causes acute infantile diarrhoea in humans and animals and remains a major concern for vaccine development. The close proximity of humans to animals may foster cross-species infection resulting in the emergence of novel/unusual strains by genetic reassortment. In this study, we characterized 500 diarrhoeal samples for group A rotaviruses (RVA) from children (n = 290), piglets (n = 95) and calves (n = 115) in Northeast India during 2012–2013. The data showed that 142/500 (28·4%) faecal samples were positive for RVA with the highest level of infection detected in piglets (57/142, 40·1%) followed by children (51/142, 35·9%) and calves (34/142, 23·9%). Sequence-based G- and P-typing showed G1P (25%) and G1P (35%) were the prevailing genotypes in both humans and animals. Single cases of unusual genotypes, i.e. G9P, G5P in humans and G1P, G1P and G3P in animals were also identified. Cluster analyses of the sequences showed regional strains were genetically closer to their homologous strains. However, human G5P and porcine G1P strains showed homology to heterologous hosts of their prototype strains. The subsequent global spread of unusual RV strains may result in their establishment over time, presenting challenges to future vaccine evaluation programmes. More studies on emerging genotypes are required to elucidate how RVA strains evolve post-vaccination. This study supports the need for continuous surveillance of RVA infections after detecting from diverse hosts in a common setting.
Drinking raw date palm sap is the primary route of Nipah virus (NiV) transmission from bats to people in Bangladesh; subsequent person-to-person transmission is common. During December 2010 to March 2011, we investigated NiV epidemiology by interviewing cases using structured questionnaires, in-depth interviews, and group discussions to collect clinical and exposure histories. We conducted a case-control study to identify risk factors for transmission. We identified 43 cases; 23 were laboratory-confirmed and 20 probable. Thirty-eight (88%) cases died. Drinking raw date palm sap and contact with an infected person were major risk factors; one healthcare worker was infected and for another case transmission apparently occurred through contact with a corpse. In absence of these risk factors, apparent routes of transmission included drinking fermented date palm sap. For the first time, a case was detected in eastern Bangladesh. Identification of new epidemiological characteristics emphasizes the importance of continued NiV surveillance and case investigation.
A restriction fragment length polymorphism (RFLP) assay was developed to examine the genetic relationship between 67 (29 Indian, 38 global) rotavirus isolates of human, bovine and porcine neonates. The assay involved direct digestion of RT–PCR amplified VP7 cDNAs with three restriction enzymes (VspI, HaeIII, NlaIV) independently. Forty-eight RFLP patterns were identified for all 67 strains, and of these 20 patterns were associated with Indian isolates. A correlation between the restriction patterns and G type was apparent through deduction of enzyme restriction sites from known sequences. Major G serotypes (G1, G2, G6, G8) with a few mixed types could be differentiated where there was a positive assortment of intrinsic serotypes from multiple host origin, and certain single or combined enzyme profiles were highly dominant in the population. Significant genetic variations were established between global and Indian isolates and none of the RFLP patterns were shared between them. These data suggest that the Indian wild-type rotavirus population is distinguishable based on the VP7 gene, and co-circulation of distinct strains in different hosts is foremost, indicating the possible likelihood of inter-species transmission.
The spectral classifications of the stars from spectral data have been corrected from time to time and new spectral and luminosity classes have been assigned. Identifying stars with wrong spectral and luminosity classification has been a stupendous task from the huge catalogue of stars. In this work we describe a simple statistical technique to identify stars with wrong spectral and luminosity classification. We make use of the Hipparcos catalogue which has the most accurate measurement of the distance d of the stars. A comparison is made between the absolute V magnitudes MV computed using the observed V magnitude mV and d, with the standard absolute magnitude MV0 assigned to a spectral and luminosity classification for a large number of stars (with d < 100 pc). As expected, for most of the stars the difference between MV and MV0 lies within the range ±2 mag, due to the intrinsic nature of each star ignored in this generalisation. A systematic error analysis is made of all the observable used in the computation. Therefore to identify stars which we suspect to be wrongly classified, we look for abnormal deviation in |MV – MV0| ≥5. The location of these stars with respect to the galactic plain and interstellar extinction is also investigated to rule out effects due to variations in the interstellar extinction. From our results we see that some of the stars were indeed wrongly classified and have recently been reclassified (SIMBAD). The reclassification drastically reduces the |MV – MV0| deviation. The other stars in the list which have not yet been reclassified need to be spectroscopically investigated and classified again.
The West Virginia University Hot hELIcon eXperiment (HELIX) provides variable density and ion temperature plasmas, with controllable levels of thermal anisotropy, for space relevant laboratory experiments in the Large Experiment on Instabilities and Anisotropy (LEIA) as well as fundamental studies of helicon source physics in HELIX. Through auxiliary ion heating, the ion temperature anisotropy (T⊥/T∥) is variable from 1 to 20 for parallel plasma beta (β = 8πnkTi∥/B2) values that span the range of 0.0001 to 0.01 in LEIA. The ion velocity distribution function is measured throughout the discharge volume in steady-state and pulsed plasmas with laser induced fluorescence (LIF). The wavelengths of very short wavelength electrostatic fluctuations are measured with a coherent microwave scattering system. Operating at low neutral pressures triggers spontaneous formation of a current-free electric double layer. Ion acceleration through the double layer is detected through LIF. LIF-based velocity space tomography of the accelerated beam provides a two-dimensional mapping of the bulk and beam ion distribution functions. The driving frequency for the m = 1 helical antenna is continuously variable from 8.5 to 16 MHz and frequency dependent variations of the RF coupling to the plasma allow the spontaneously appearing double layers to be turned on and off without modifying the plasma collisionality or magnetic field geometry. Single and multi-species plasmas are created with argon, helium, nitrogen, krypton, and xenon. The noble gas plasmas have steep neutral density gradients, with ionization levels reaching 100% in the core of the plasma source. The large plasma density in the source enables the study of Aflvén waves in the HELIX device.
Head and face dimensions vary according to race and geographical zone. Hereditary factors also greatly affect the size and shape of the head. There are important medical applications of craniofacial data specific to different racial and ethnic groups.
Various cranial and facial anthropometric parameters were assessed in singleton, healthy, full-term newborns of Sikkimese origin in a tertiary care hospital in Sikkim, India. The data were then analysed to determine statistically significant differences between sexes.
Forty-five newborns were included in the study. Both male and female newborns were observed to be hyperbrachycephalic and hyperleptoprosopic. The only significant difference between the sexes was in commissural length, which was observed to be greater in male newborns.
Craniofacial parameters in Sikkimese newborns vary in comparison with those of other newborns from around the world. Larger studies are needed in order to reveal sex-related variations. Similar studies on various racial groups in North-East India are needed to establish standards for populations with East Asian features.
Socio-behavioural factors and pathogens associated with childhood diarrhoea are of global public health concern. Our survey in 696 children aged ⩽2 years in rural West Bengal detected rotavirus as sole pathogen in 8% (17/199) of diarrhoeic stool specimens. Other organisms were detected along with rotavirus in 11% of faecal specimens. A third of the children with rotavirus diarrhoea, according to Vesikari score, had severe illness. The top four rotavirus genotypes were G9P (28%), G1P (19%), G2P (14%) and G8P (8%). In the multivariate model, the practice of ‘drawing drinking water by dipping a pot in the storage vessel’ [adjusted odds ratio (aOR) 2·21, 95% confidence interval (CI) 1·03–4·74, P = 0·041], and ‘children aged ⩽6 months with non-exclusive breastfeeding’ (aOR 2·07, 95% CI 1·1–3·82, P = 0·024) had twice the odds of having diarrhoea. Incidence of rotavirus diarrhoea was 24/100 child-years in children aged >6–18 months, 19/100 child-years in children aged >18–24 months and 5/100 child-years in those aged ⩽6 months. Results have translational implications for future interventions including vaccine development.
Direct numerical simulation (DNS) of liquid film flow is used to compute fully developed solitary waves and to compare their characteristics with the predictions of low-dimensional models. Emphasis is placed on the regime of high inertia, where available models provide widely differing results. It is found that the parametric dependence of wave properties on inertia is highly non-trivial, and is satisfactorily approximated only by the four-equation model of Ruyer-Quil & Manneville (Eur. Phys. J. B, vol. 15, 2000, pp. 357–369). Detailed comparison of the asymptotic shapes of upstream and downstream tails is performed, and inherent limitations of all long-wave models are revealed. Local flow reversal in front of the main hump, which has been previously discussed in the literature, is shown to occur for an inertia range bounded from below and from above, and the boundaries are interpreted in terms of the capillary origin of the phenomenon. Computational results are reported for the entire range of Froude numbers, providing benchmark data for all wall inclinations.
Unprecedented high rates of anthrax outbreaks have been observed recently in cattle and humans in Bangladesh, with 607 human cases in 2010. By enrolling 15 case and 15 control cattle smallholdings in the spatial zone in July–September 2010, we conducted a case-control study, data of which were analysed by matched-pair analysis and multivariable conditional logistic regression. Feeding animals with uprooted and unwashed grass [odds ratio (OR) 41·2, 95% confidence interval (CI) 3·7–458·8, P=0·003], and feeding water hyacinth (Eichhornia crassipes) (OR 22·2, 95% CI 1·2–418·7, P=0·039) were independent risk factors for anthrax in cattle.
Use of the veterinary drug diclofenac is responsible for bringing three species of Gyps vultures endemic to South Asia to the brink of extinction, and the Government of India banned veterinary use of the drug in May 2006. To evaluate the effectiveness of the ban we undertook surveys of > 250 veterinary and general pharmacies in 11 Indian states from November 2007 to June 2010. Twelve different classes of non-steroidal anti-inflammatory drugs (NSAIDs) were purchased from 176 pharmacies. Other than meloxicam (of negligible toxicity to vultures at likely concentrations in their food), diclofenac and ketoprofen (both toxic to vultures), little is known of the safety or toxicity of the remaining nine NSAIDs on sale. Meloxicam was the most commonly encountered drug, sold in 70% of pharmacies, but 50% of the meloxicam brands sold had paracetamol (acetaminophen) as a second ingredient. Diclofenac and ketoprofen were recorded in 36 and 29% of pharmacies, respectively, with states in western and central India having the highest prevalence of diclofenac (44–45%). Although the large number of manufacturers and availability of meloxicam is encouraging, the wide range of untested NSAIDs and continued availability of diclofenac is a major source of concern. Circumvention of the 2006 diclofenac ban is being achieved by illegally selling forms of diclofenac manufactured for human use for veterinary purposes. To provide a safer environment for vultures in South Asia we recommend reducing the size of vials of diclofenac meant for human use, to increase the costs of illegal veterinary use, and taking action against pharmaceutical manufacturers and pharmacies flouting the diclofenac ban.
We have conjugated chloroquine onto nano-sized, thiol-stabilized gold nanoparticles by using 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride (EDC) / N-hydroxysulfosuccinimide (NHS) chemistry. The formation of gold nanoparticles was confirmed using optical spectra for characteristic surface plasmon band; the average size of gold nanoparticles was found to be 5-7 nm from electron microscopy measurements. The anti-tumor activity of prepared nanocomposite, vis-à-vis chloroquine itself, had been demonstrated using MCF-7 breast cancer cell line. To determine the binding affinity of gold-chloroquine nanocomposites to transport proteins present in blood serum, we studied the binding interaction of gold-chloroquine to bovine serum albumin (BSA), the most abundant plasma protein. The binding was studied by using isothermal titration calorimetry and fluorescence spectroscopy and was analyzed in terms of binding constant, entropy and enthalpy change. The gold-chloroquine nanocomposites were found to interact efficiently with BSA and fluorescence quenching experiments involving Trp212 suggests that the nanocomposites bind at site I of BSA.
Water stable fluorescent ZnO quantum dots (QDs) have been synthesized by wet chemical route in presence of hydrophilic capping agent polyethyleneimine (PEI) as stabilizing agent. The binding interaction of prepared ZnO QDs is studied with bovine serum albumin (BSA) protein. X-ray diffraction measurement reveals hexagonal wurtzite structure of as synthesized ZnO QDs with an average size 4-6 nm, determined using Scherer’s equation and confirmed by transmission electron microscopy (TEM). The ZnO/PEI QDs exhibit strong yellow-green emission centered at 555 nm (2.23 eV). The interaction between BSA and ZnO/PEI QDs has been studied by using spectroscopic and calorimetric methods. Static mode of tryptophan quenching in BSA by ZnO/PEI QDs indicates that a ground state complex formation is taking place between ZnO/PEI and BSA, where, the week interactions (hydrogen bonding and hydrophobic interaction) are contributing towards the stability of the complex.
Substantial amount of fixed charge present in most of the alternative gate dielectrics gives rise to large shifts in the flat-band voltage (VFB) and charge trapping and de-trapping causes hysterectic changes on voltage cycling. Both phenomena affect stable and reliable transistor operation. In this paper we have studied for the first time the effect of post-metallization hydrogen annealing on the C-V curve of MOS capacitors employing zirconia, one of the most promising gate dielectric. Samples were annealed in hydrogen ambient for up to 30 minutes at different temperatures ranging from room temperature to 400°C. C-V measurements were done after annealing at each temperature and the hysteresis width was calculated from the C-V curves. A minimum hysteresis width of ∼35 mV was observed on annealing the sample at 200°C confirming the excellent suitability of this dielectric.