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The pandemic of Coronavirus disease 2019 (COVID-19) is rapidly progressing, causing significant morbidity and mortality. Various antiviral drugs, anti-inflammatory drugs, and immunomodulators have been tried without substantial clinical benefits. The severe and critical cases of COVID-19 disease are characterised by gut microbiome dysbiosis, immune dysregulation, hyper-inflammation, and hypercytokinemia (cytokine storm). Therefore, the strategies which target these pathophysiological processes may be beneficial. Probiotics are one such strategy that exerts beneficial effects by manipulation of the gut microbiota, suppression of opportunistic pathogens in the gut, decrease translocation of opportunistic organisms, activate mucosal immunity, and modulation of the innate and adaptive immune response. Probiotics are the potential candidates to be tested in moderate and severe cases of COVID-19 due to several beneficial effects, including easy availability, easy to administer, and safe, and economical to use.
We present a robot navigation system based on Behavioral Finite State Social Machine. The paper makes a robot operate as a social tour guide that adapts its navigation based on the behavior of the visitors. The problem of a robot leading a human group with a limited field-of-view vision is relatively untouched in the literature. Uncertainties arise when the visitors are not visible, wherein the behavior of the robot is adapted as a social response. Artificial potential field is used for local planning, and a velocity manager sets the speed disproportional to time duration of missing visitors.
In this paper, a high gain wideband circularly polarized (CP) microstrip antenna is presented for broadband operation. The proposed structure comprised of a partially grounded printed monopole antenna loaded with a split ring resonator and a metallic reflector. By using the metallic reflector surface underneath the patch radiator results in the reflected waves in the same phase with main lobe radiation, thereby improving the gain and it also acts like a secondary radiator to generate wideband CP behavior in the proposed design. A gain enhancement of 4.3 dBi is achieved in the operating frequency band as compared with the design without a metallic reflector. The maximum gain achieved in the presented method is 8.6 dBic over the entire operating range. The proposed design shows a wideband behavior ranging from 4.30 to 9.10 GHz with the 10-dB impedance bandwidth of 71.64%. In addition, the proposed design yielded a broadside right hand CP radiation with a 3-dB axial ratio bandwidth of 33.88% from 4.98 to 7.01 GHz. The proposed antenna is fabricated and experimental results on reflection coefficient, gain, axial ratio, and radiation patterns concede well with simulation results.
Upper water column dynamics in the eastern Arabian Sea were reconstructed in order to investigate changes in the activity of the South Asian / Indian monsoon during the early Pleistocene (c. 1.5–2.7 Ma). We used planktic foraminiferal assemblage records combined with isotopic (δ18O and δ13C) data, Mg/Ca-based sea surface temperatures and seawater δ18O records to estimate changes in surface water conditions at International Ocean Discovery Program (IODP) Site U1457. Our records indicate two distinct regimes of monsoon-induced changes in upper water structure during the periods c. 1.55–1.65 Ma and c. 1.85–2.7 Ma. We infer that a more stratified upper water column and oligotrophic mixed layer conditions prevailed during the period 1.85–2.7 Ma, which may be due to overall weaker South Asian / Indian winter (NE) and summer (SW) monsoon circulations. The period 1.55–1.65 Ma was characterized by enhanced eutrophication of the mixed layer, which was probably triggered by intensified winter (NE) monsoonal winds. The long-term trend in hydrographic changes during 1.55–1.65 Ma appears to be superimposed by short-term variations, probably reflecting glacial/interglacial changes. We suggest that an intensification of the South Asian / Indian winter monsoon circulation occurred between ∼1.65 Ma and 1.85 Ma, which is most likely due to the development of strong meridional and zonal atmospheric circulations (i.e. Walker Circulation and Hadley Circulation) because of strong equatorial East–West Pacific temperature gradients.
Founded in 1956, the Administrative Staff College of India (ASCI) was established with the objective of professionalizing management in post-colonial India through training, research, and consultancy. It was modeled on the Administrative Staff College at Henley-on-Thames (Henley), in the United Kingdom. Like Henley, ASCI used syndicates for its management training programs. Between 1958 and 1973, ASCI received more than $1.26 million from the Ford Foundation, part of which was used to finance the development and use of the case method in ASCI’s training programs, and later more widely in its research and consultancy. This article traces the ways by which the Ford Foundation––as a dominating institution––stigmatized Henley and ASCI, their institutional practices, and the wider Indian society; and legitimized the case method pioneered at the Harvard Business School. Imbricated in the Cold War’s geo-politics, Ford Foundation’s interventions in Hyderabad should be understood as part of the emergence of the United States as the dominant neo-colonial power, which required the displacement of Britain, its institutions, and their practices as the template for India’s post-colonial management institutions.
Shunt-related adverse events are frequent in infants after modified Blalock–Taussig despite use of acetylsalicylic acid prophylaxis. A higher incidence of acetylsalicylic acid-resistance and sub-therapeutic acetylsalicylic acid levels has been reported in infants. We evaluated whether using high-dose acetylsalicylic acid can decrease shunt-related adverse events in infants after modified Blalock–Taussig.
In this single-centre retrospective cohort study, we included infants ⩽1-year-old who underwent modified Blalock–Taussig placement and received acetylsalicylic acid in the ICU. We defined acetylsalicylic acid treatment groups as standard dose (⩽7 mg/kg/day) and high dose (⩾8 mg/kg/day) based on the initiating dose.
There were 34 infants in each group. Both groups were similar in age, gender, cardiac defect type, ICU length of stay, and time interval to second stage or definitive repair. Shunt interventions (18 versus 32%, p=0.16), shunt thrombosis (14 versus 17%, p=0.74), and mortality (9 versus 12%, p=0.65) were not significantly different between groups. On multiple logistic regression analysis, single-ventricle morphology (odds ratio 5.2, 95% confidence interval of 1.2–23, p=0.03) and post-operative red blood cells transfusion ⩾24 hours [odds ratio 15, confidence interval of (3–71), p<0.01] were associated with shunt-related adverse events. High-dose acetylsalicylic acid treatment [odds ratio 2.6, confidence interval of (0.7–10), p=0.16] was not associated with decrease in these events.
High-dose acetylsalicylic acid may not be sufficient in reducing shunt-related adverse events in infants after modified Blalock–Taussig. Post-operative red blood cells transfusion may be a modifiable risk factor for these events. A randomised trial is needed to determine appropriate acetylsalicylic acid dosing in infants with modified Blalock–Taussig.
Occurrence of Salmonella spp. in captive wild animal species in India is largely unknown. The purpose of this study was to determine the occurrence of different Salmonella serotypes, antimicrobial resistance patterns and genotypic relatedness of recovered isolates. A total of 370 samples including faecal (n = 314), feed and water (n = 26) and caretakers stool swabs (n = 30) were collected from 40 different wild animal species in captivity, their caretakers, feed and water in four zoological gardens and wildlife enclosures in India. Salmonellae were isolated using conventional culture methods and tested for antimicrobial susceptibility with the Kirby–Bauer disc diffusion method. Salmonella isolates were serotyped and genotyping was performed using enterobacterial repetitive intergenic consensus (ERIC) PCR and 16S rRNA sequencing. Animal faecal samples were also subjected to direct PCR assay. Salmonella was detected in 10 of 314 (3.1%) faecal samples by isolation and 18 of 314 (5.7%) samples by direct PCR assay; one of 26 (3.8%) feed and water samples and five of 30 (16.7%) caretakers stool swabs by isolation. Salmonella was more commonly isolated in faecal samples from golden pheasants (25%; 2/8) and leopard (10%; 2/20). Salmonella enterica serotypes of known public health significance including S. Typhimurium (37.5%; 6/14), S. Kentucky (28.5%; 4/14) and S. Enteritidis (14.3%; 2/14) were identified. While the majority of the Salmonella isolates were pan-susceptible to the commonly used antibiotics. Seven (43.7%; 7/16) of the isolates were resistant to at least one antibiotic and one isolate each among them exhibited penta and tetra multidrug-resistant types. Three S. Kentucky serotype were identified in a same golden pheasants cage, two from the birds and one from the feed. This serotype was also isolated from its caretaker. Similarly, one isolate each of S. Typhimurium were recovered from ostrich and its caretaker. These isolates were found to be clonally related suggesting that wildlife may serve as reservoir for infections to humans and vice versa. These results emphasise the transmission of Salmonella among hosts via environmental contamination of feces to workers, visitors and other wildlife.
The electrochemical technique has been used to prepare aluminum-doped zinc oxide (AZO) films on FTO substrates using zinc nitrate and aluminum chloride precursor solution at 70 °C. The crystal structure, surface morphology, optical and electrical features of AZO films were examined at different potential voltages from −1.7 to −2.3 V in the initial solution. Structural studies of the deposited films were carried out through X-ray diffraction; the AZO films exhibited a polycrystalline nature with hexagonal structure, and crystals preferentially grew along the (002) orientation. The morphology of the deposited films was characterized by scanning electron microscopy (SEM), and the images showed that the spherical- and nanorod-shaped particles are uniformly distributed on the entire AZO film surface. The average size is found to be in the range of 45–70 nm by SEM and 28–32 nm by using the Scherrer’s rule. The EDS spectrum confirmed the chemical composition of Zn, O, Al, Sn, and F elements over the film surface. The optical properties were studied using a UV-visible spectrophotometer, and the deposited film showed the highest optical transmittance of ∼80% in the visible range for −1.7 V. The calculated energy gap of the AZO films decreases from 3.09 to 2.97 eV with increasing potential voltages. AZO thin films have been studied using photoluminescence to identify the film’s optical quality with respect to the wavelength range. The electrical properties were studied by the room temperature Hall effect system, and the observed low resistivity (ρ) is 1.58 × 10−2 (Ω cm) for the film deposited using a −2.1 V potential voltage.
In this work, morphology, viability, and metabolism of the amniotic mesenchymal stem cells conditioned with different citric acid (CA)/media ratios were investigated using rhodamine-phalloidin/4′,6-diamidino-2-phenylindole staining, live/dead assay, proliferating cell nuclear antigen, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL assay). The cells cultured in 25:75 CA/media displayed well spread actin filaments with a prominent nucleus and evidenced optimum viability. The gelation kinetics of chitosan solution in CA/media (25:75) was monitored via dynamic time sweep analysis on a rheometer. The chemical cross-linking of chitosan with CA was confirmed by nuclear magnetic resonance studies. Subsequently, chitosan solution was extruded in CA/media bath containing cells under benign conditions to form cell-laden fibers (living fibers). The prelabeled cells imaged immediately after fiber formation confirmed the attachment of the cells on the fibers. This approach has several advantages including instantaneous gelation, tunable mechanical properties, and adjustable biodegradability that can provide a platform technology for creating viable three dimensional (3D) building blocks for tissue engineering applications.
The present study aimed to evaluate growth performance and meat quality of broiler chicken with respect to feeding of 100 g flaxseed meal (FM)/kg and increasing lysine levels in the broiler diet. The results revealed no effect of lysine and FM feeding on growth performance except for a negative effect of FM on feed efficiency of birds, which was countered by feeding 1.25 BIS lysine. Feeding FM improved the fatty acid profile of broiler chicken meat significantly, whereas no effect was observed for increasing lysine levels beyond BIS recommendation. FM significantly reduced meat cholesterol, fat, water-holding capacity (WHC), extract release volume (ERV) and antioxidant potential, whereas it increased the pH of fresh meat, drip loss and lipid peroxidation of broiler chicken meat. As compared with other lysine levels, generally 1.25 BIS lysine significantly increased the pH of refrigerated stored meat, WHC, ERV and antioxidant potential, whereas it significantly reduced cholesterol, fat, drip loss and lipid peroxidation of broiler chicken meat. Thus, the inclusion of 100 g FM/kg diet along with 1.25 BIS lysine in broiler ration was optimum for desirable broiler performance, fatty acid profile, oxidative stability and other functional properties of broiler chicken meat.
This study investigates the shock transformation in an underexpanded jet in a confined duct when the jet total pressure is increased. Experimental study reveals that the Mach reflection (MR) in the fully underexpanded jet transforms to a regular reflection (RR) at a certain jet total pressure. It is observed that neither the incident shock angle nor the upstream Mach number varies during the MR–RR shock transformation. This is in contradiction to the classical MR–RR transformations in internal flow over wedges and in underexpanded open jets. This transformation is found to be a total pressure variation induced transformation, which is a new kind of shock transformation. The present study also reveals that the critical jet total pressures for MR–RR and RR–MR transformations are not the same when the primary pressure is increasing and decreasing, suggesting a hysteresis in the shock transformations.
In this chapter, we discuss four basic sampling designs, namely, simple random sampling (SRS), stratified sampling, systematic sampling and cluster sampling. In the process of sample selection, it is possible to select elements directly, if a suitable sampling frame for their selection is available. Often, sampling frame is available only for a group of individual elements, instead of each element. These groups of individual elements, generally some areal units, are commonly referred to as clusters. If the sampling frame for each cluster in a population is available, the sample can be selected either in one stage or at multiple stages. In one stage, in a selected cluster, all the elements comprising it will be automatically included in a sample. Selection in two or more stages, discussed in Chapters 3 and 4, involves selection of elements from selected clusters.
Of the four designs, mentioned above, SRS and systematic sampling are the two basic methods for selection of sampling units (either units or clusters). Both provide equal chance to each sampling unit for inclusion in a sample. Another variant, known as PPS sampling wherein sampling units are selected with varying probability, is also elaborated here. Further, we discuss stratified sampling which is a technique of grouping sampling units in a population before selection where grouping is done to put restrictions on selection of a combination of sampling units to benefit the procedure of selection. The cluster sampling in which all the elements in a selected cluster are included in a sample is generally avoided. However, it facilitates understanding multistage designs. In each of the next four sections, we outline the essential steps in a design. They are as follows:
• Methods of selection of sampling units,
• Estimation of a parameter, and
• Providing estimate of the error such as sampling variance of an estimate.
SIMPLE RANDOM SAMPLING
In this design, each and every sampling unit in a population receives equal chance of being included in a sample. The method is discussed assuming individual units as the sampling units, but remains true even if group of units, instead of individual units, is considered. Let there be N units in a population from which n are to be selected for inclusion in a sample.
The twenty-first century is the Century of Information. Scientifically designed gathering, collation, analyses, interpretation, sharing and dissemination of information have become the primary occupation of millions, as the activity encompasses the widest possible spectrum of subjects ranging from education to development including social sciences, developmental economics and planning, medical sciences, engineering and even commercial subjects such as marketing and branding. The two major pillars in this grand edifice are ‘survey designs’ and ‘evaluation designs’. In spite of the significant potential of statistical designs in the development of valid and reliable information, there is a wide and visible gap between development of theory and its practice.
Professor Leslie Kish, one of the world's top survey statisticians, once commented in his paper ‘The Hundred Years’ Wars of Survey Sampling’, “my central complaint is that over 95% of statistical attention in academia, textbooks and publications is devoted to mathematical statistical analysis and only 2% to design” (Kish, 2003a). With regard to attention to designs, his comment is as apt as ever. This is a rather unfortunate situation, particularly since the two designs can compliment and nurture each other's application and growth. Professor Kish continued to remark “the consequences of that neglect are too often poor designs by non-statisticians (engineers, economists etc.)”. Given this, the present book is a modest attempt to provide practitioners with tools for application of both designs, irrespective of their field of expertise.
A BRIEF HISTORY OF TWO DESIGNS
Understanding the prevalence of variables and their causal relationships has long been the prime focus of research. Initially, the interest was on obtaining a count of the population, such as adult population for tax purposes as well as for enrolment in the military, availability of land for habitation and agriculture etc. Graunt (1662) estimated the population of London around the year 1662. Utilising parish registers, he first estimated the ratio of number of burials per family. In fact, he observed that there would be 3 burials per 11 families in a year. He also obtained the total number of burials in London. With the help of the total and the ratio, he then estimated the total number of families. An assumption about the average family size then resulted in the estimated total population of the country (Bethlehem, 2009). Laplace used a type of survey to estimate the population of France in around the year 1812.
Availability of a sampling frame is a basic requirement for application of a probability sampling technique. In order that each and every element in a population has a known and non-zero chance of being included in a sample, an ideal frame should consist of all elements occurring only once and it should exclude any other element that is irrelevant for the study. The basic techniques, such as SRS, stratified sampling and systematic sampling, discussed in Chapter 2, presume availability of such a list of elements if elements are being selected directly. In cluster and multistage sampling, a list of all areal units comprising a population is required initially. They are often selected using a PPS sampling (also discussed in Chapter 2), which assumes an availability of size or at least an estimated size of each cluster. For selection of elements in the final stage of a multistage design, a frame consisting of elements in selected areas would be required. This is generally obtained through listing of dwellings or households in a population-based survey.
It is indeed difficult to have a perfect frame in every situation. Let us consider, for example, a common situation of studying a population having certain characteristics, say, suffering from a particular disease. A usual available list will consist of both the elements, households having a member suffering from the disease and those without anyone suffering. The latter element may be irrelevant and, therefore, considered as a blank.
The present chapter discusses a few applications of probability sampling in the absence of an ideal frame, following three broad situations that are generally encountered:
(a) Sampling populations having specific attributes, that is, a frame consisting of elements as well as blanks.
(b) Sampling populations using a defective frame, that is, a frame which is either incomplete or consists of duplications (same element occurring more than once).
(c) Sampling populations in the absence of any frame.
In addition, the chapter also includes a discussion on household listing that is advisable in implementing a cluster sampling.
SAMPLING POPULATIONS HAVING SPECIFIC ATTRIBUTES
This situation arises when a survey objective refers to not all the elements in a population but to a section of it.