bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental and analytical study on hybrid composite and its performance on column
Authors: Sara Kurian Jency , Mary Jacob Glen
Published: April 2021

Composite materials are defined as the sum of matrix and reinforcement materials. Hand layup technique is mostly used by researchers for the fabrication of composite. The present work aims to determine the mechanical strength of hybrid composite (flax-glass-epoxy, jute-glass-epoxy, flax-epoxy, and glass-epoxy). Obtained experimental results were validated with finite element analysis using ANSYS software. Analytical study on performance of NSM GFRP bars along with hybrid composite as external strengthening for columns was evaluated using ANSYS software.
Sustainable Utilization of Lightweight Waste Materials as Structural fill for Geotechnical Applications
Authors: Shireen K , Varghese R M , Sankar N
Published: April 2021

In spite of the development foreseen by our economy over this century, abundant quantity of waste materials is being generated in various sectors such as transportation, power generation and industries. Meanwhile, constructional activities across the globe demand virgin natural materials. This paper emphasis a review on the use of some of the waste materials like Fly ash (FA), Bottom ash (BA), Tire derived Materials (TDM) in lieu of natural geomaterials as lightweight fills for retaining walls and embankments. A brief review of the engineering behavior of these waste materials which makes them a competent fill material will be presented here. Further full scale and model studies of embankments and retaining walls utilizing these wastes for fill application is also emphasized. The results of these studies have shown that these waste materials can act as competent fill material for geotechnical applications.
Adaptability and transformability of socio-ecological system: Exploring the resilience of Mulavukad panchayat in Ernakulum district of Kerala
Authors: Bindu C A , Subha V
Published: April 2021

The functioning of our community is dependent on the social, economic, environmental & physical components and the interplay between them. Disruption of one component can affect the others and can damage the functioning of the entire system. The variations in damage caused by stress, shocks etc depends on the ability of the social, physical, economic, ecological and institutional capacities to absorb them. This paper focuses on the theory of adaptive cycle and the adaptations & transformations underwent in Mulavukad panchayat is overlaid on the adaptive cycle to envisage and collate the occurrences. Mulavukad panchayat lies a few kilometres from Kochi city, which is the most urbanized city in the state of Kerala. The panchayat comprising of Bolgatty and Vallarpadam Islands has a total area of 19.25 Sq. km with a population of 21833. The introduction of Goshree Bridge in 2004 brought dramatic changes to the community that resonated in all sectors. The study shows that the social, ecological and economic system in this panchayat underwent adaptations and transformations in relation to the changing scenarios.
Evaluation of tribological characteristics of natural garlic oil as an additive in rubber seed oil
Authors: Jesbin K S , Mahipal D
Published: April 2021

Industrial oils have the essential elements of a lubricant, but their environmental feasibility and economic effect are insufficient. Vegetable oils are emerging as an alternative to industrial lubricants. The production of oil from energy resources, such as vegetable seed oils, is important. Rubber seed oil has been shown to be of greater value among the base stock of bio lubricants, since it contains large concentrations of unsaturated fatty acids. The effectiveness of natural garlic oil as an additive in rubber seed oil in enhancing the tribological characteristics of steel/steel contact is conducted in this research. The findings are compared with SAE20W40 oil data. Friction and wear experiments were carried out using a four-ball tribotesting machine. Additive added rubber seed oil offered low friction values compared to mineral oil. The newly produced oil was tested by a kinematic viscometer. Improvement in the viscosity index was demonstrated by additive added rubber seed oil.
Comparative fluidity study of AA7075 unreinforced alloy and Al2O3 reinforced composite
Authors: Roshitha P A , Arun M S
Published: April 2021

Aluminium alloys are used extensively in the automobile and aerospace areas. The reason behind this is the high strength to weight ratio of aluminium and its alloys. As requirement for better materials arose, the existing aluminium alloys evolved into composite forms. Composites can enhance the mechanical properties of the metal matrix. The property which gets improved depends upon the reinforcement. But the problem associated with composites is their poor fluidity. There are only a handful of researches conducted to evaluate the effects of reinforcing agents on composite fluidity. Fluidity is expressed in terms of fluidity length or flow length. It is defined as the maximum length the molten metal will flow in a long channel before solidifying. In this work, the fluidity characteristics of AA7075 alloy and AA7075 alloy reinforced with aluminium oxide (Al2O3) are explored. It was found that the fluidity length of aluminium alloy AA7075 decreased by almost 20 cm on addition of the reinforcing agent, aluminium oxide. This may be due to the tendency of alumina particles to cluster together or accumulate in the aluminium matrix. This increases the viscosity and thereby reduces the fluidity length.
Influence of cryogenic and chemical treatment on thermal and physical properties of hemp fabric
Authors: Thomas Lijin , Mubarak Ali M , Aju Kumar V N , Thomas Sabu
Published: April 2021

Conventional synthetic materials in engineering applications are imprinting our ecosystem with non-biodegradable wastes. Environmental awareness throughout the world has influenced materials design and selection, which is leading to orientation from synthetic to biodegradable materials. Efforts are put to improve the properties of existing natural materials for engineering applications. In this study hemp fabric was subjected to alkalization, maleic anhydride treatment and cryogenic treatment, to improve the fabric’s physiochemical properties. Differential scanning calorimetry (DSC), Thermo gravimetric analysis (TGA), and Differential Thermo gravimetric Analysis (DTG) were used to investigate the changes in thermal behaviour of untreated and treated fabric. Physical properties such as functional groups of fabrics were studied and compared with Fourier Transform Infrared Spectroscopy (FTIR). Alkalization and maleic anhydride treatment on fabric have substantially increased the number of hydrogen bonding in cellulose, which lead to increase in stiffness of the fabric. Thermal stability of hemp fabric has increased significantly with cryogenic treatment. An increase in the cellulose composition after the cryogenic treatment shows better physical properties. These observations give hemp fibbers wide range of opportunity to be part of engineering applications with thermal stability, stiffness, and eco-friendly requirements.
Preparation and characterization of thermal conductivity enhanced shape stabilized phase change composite for thermal energy storage
Authors: Manju M S , Alandev S
Published: April 2021

Thermal energy management is fetching more importance, recently in many sectors including chemical/petrochemical, automotive, aerospace, and electronics. An attempt has been done on the investigation in thermal energy storage (TES) applications using phase change composites. To make the composite material suitable for potential devices the thermal conductivity should be high. For achieving this, fillers with higher thermal conductivity can be incorporated into polymers to form polymer composites. In the light of background study on the recent researches in this area, nanocomposites are expected to show good thermal conductivity behavior. In this work, ZnS/PMMA nanocomposites are used as the conductive polymer for thermal energy storage in which the ZnS nanoparticles are used as the fillers. The solution casting method is used to prepare the nanocomposites. Samples based on the weight percentage of filler are used for characterization. The thermal stability and conductivity of the composite material are evaluated using TGA and Thermal Conductivity Apparatus. The SEM analysis of ZnS particles shows the nanoscale size and morphology suitable for filler components. An enhancement of 72% in thermal conductivity is noted for the 6% (ZnS) sample with PMMA.
Ultrasound-assisted synthesis and characterization of sesame oil based nanoemulsion
Authors: Namratha Vinaya Kumar , Mary John Ann , Mangsatabam Mona , Anna Philip Mercy
Published: April 2021

Nanoemulsions are emulsions having droplet sizes in the nanometre range. Nano emulsions have unique properties such as robust stability, transparent nature, high surface area, and tunable rheology. The present study focuses on the synthesis of sesame oil-based nanoemulsion using ultrasonic emulsification to break down particle size to nanometric range. The method uses small surfactant concentration and low energy to synthesize homogenous nanoemulsion. The emulsion is stabilized using Tween 20 surfactant. Aqueous nanoemulsion samples were prepared using sesame oil by varying the surfactant concentration to determine the most stable composition, and different properties of each sample prepared, were analyzed. The ultrasonication time was also varied to study the impact of sonication time. Nanoemulsions formed were then evaluated for their various properties. The droplet size and zeta potential for all samples were determined by the Dynamic Light Scattering technique wherein the best nanometer size distribution was found to be at 1:3 (oil: surfactant) composition. The physical stability was determined using a centrifuge at 3000 rpm. Conductivity, pH, and density of the samples were then measured. A polydispersity index of 0.514 was obtained for the sample of oil: surfactant ratio 1:3. Fourier Transform Infrared Spectroscopy studies were conducted for all samples.
Aqueous two-phase extraction of lead from contaminated aqueous solutions
Authors: Suji S K , Radhakrishnan K B
Published: April 2021

Aqueous two-phase extraction is an ecologically safe method for heavy metal recovery and regeneration from contaminated aqueous solutions. Investigation has been carried out experimentally for the extraction of lead from aqueous solutions using Polyethylene Glycol 1500-Ammonium sulfate two-phase system. The extracting agent used is sodium chloride. Aqueous two-phase extraction experiments for Pb(II) have been performed in batch mode according to the central composite design under Response Surface Methodology. The effect of independent parameters as to the extractant concentration, initial salt solution pH, and initial salt phase metal concentration on the extraction efficiency has been studied experimentally. The results indicate that all the three independent parameters studied have significant effect on extraction efficiency. A second-order polynomial model has been used to fit the dependent variable in the experimental range of parameters. The maximum extraction efficiency obtained from the model is about 51% atinitial salt solution pH of 2.8, NaCl concentration of 49.9mmol/Land initial salt phaselead concentration of 9.8 mg/L. This is in agreement with the results obtained from the experiment conducted at optimum conditions.
The oxygenic photogranule for wastewater treatment process
Authors: Muhammed Adil , Poduval Avatar N , Oonnikrishnan Piyush , Narayanan Pranav K , Yaduraj K
Published: April 2021

Wastewater treatment is an energy-intensive process. During secondary wastewater treatment, unwanted characteristics like Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD) etc. are reduced to permissible levels with the help of bacteria as this is a microbe driven process. A novel method of cultivating Oxygenic Photo Granules (OPGs) which are natural aggregates predominantly consisting of cyanobacteria from the activated sludge and using it to treat the wastewater in the secondary treatment is under development. After the primary treatment, OPGs help to substitute the high energy-consuming aeration equipment which deems the secondary process more sustainable. Cultivation of OPGs is influenced by many factors including the intensity of light used during cultivation, the concentration of sludge etc. Manipulating these factors, we can cultivate OPGs in the most efficient way possible. The objective of this work is the optimization of the time constraints for developing OPG samples, then analyze the energy saving of this process at a pilot scale. OPGs substitute the aeration equipment in the secondary treatment process, and they are mix evenly with the wastewater to be treated in a sequential batch reactor. Upon continuous stirring followed by settling and decanting, the wastewater is treated and analyzed. Utilization of OPGs in wastewater treatment not only saves energy but is also efficient than the conventional method, thereby making this process a more economical option.
Unisim Based Simulation and Analysis of Crude Oil Distillation
Authors: Rahman Shamna A , Anjana R
Published: April 2021

Crude distillation is the process of separating the hydrocarbons in crude oil based on their boiling point. Though refining process consists of a wide variety of units the major part is done in Crude Distillation Unit (CDU). In this study an attempt is made to make a train of heat integration network for the crude distillation process. Steady state simulations of cases with different arrangement of heat exchangers were studied in this work. Since the cost of energy has increased dramatically in last year’s, the ability to optimize the use of resources and in particular of energy is becoming an extremely important skill for chemical engineers. Steady state simulation and dynamic simulation of crude plant with optimized heat exchanger design were then performed using Unisim software.
Photoconductive emitters for pulsed terahertz generation
Authors: Bacon David R , Madéo Julien , Dani Keshav M
Published: April 2021

Conceived over 30 years ago, photoconductive (PC) emitters have proved essential in the development and spread of terahertz technology. Since then, not only have they been used extensively in a wide range of spectroscopic and imaging applications, they have also undergone significant improvements in performance, leading to their use for broadband or non-linear spectroscopy. In this review article, we provide an overview of the literature, highlighting the key milestones in the progression of the PC emitter. We also investigate the future of PC technology and review the existing challenges.
P38 COVID-19 impact on Surgical Training And Recovery Planning (COVID-STAR) Survey
Authors:   COVID-STAR collaborative research group
Published: April 2021

Background

The COVID-19 pandemic has resulted in dynamic changes to healthcare delivery. Surgery as a specialty has been significantly affected and with that the delivery of surgical training.

Method

This national, collaborative, cross sectional study comprising 13 surgical trainee associations distributed a pan surgical specialty survey on the COVID-19 impact on surgical training over a 4-week period (11th May - 8th June 2020). The survey was voluntary and open to medical students and surgical trainees of all specialties and training grades. All aspects of training were qualitatively assessed. This study was reported according to STROBE guidelines.

Results

810 completed responses were analysed. (M401: F 390) with representation from all deaneries and training grades. 41% of respondents (n = 301) were redeployed with 74% (n = 223) redeployed > 4 weeks. Complete loss of training was reported in elective operating (69.5% n = 474), outpatient activity (67.3%, n = 457), Elective endoscopy (69.5% n = 246) with > 50% reduction in training time reported in emergency operating (48%, n = 326) and completion of work-based assessments (WBA) (46%, n = 309). 81% (n = 551) reported course cancellations and departmental and regional teaching programmes were cancelled without rescheduling in 58% and 60% of cases respectively. A perceived lack of Elective operative exposure and completions of WBA’s were the primary reported factor affecting potential training progression. Overall, > 50% of trainees (n = 377) felt they would not meet the competencies required for that training period.

Conclusion

This study has demonstrated a perceived negative impact on numerous aspects of surgical training affecting all training specialties and grades.
INCIPIENT GENOME DIFFERENTIATION IN GOSSYPIUM. I. CHROMOSOMES 14, 15, 16, 19 AND 20 ASSESSED IN G. HIRSUTUM, G. RAIMONDII AND G. LOBATUM BY MEANS OF SEVEN A-D TRANSLOCATIONS
Authors: Menzel Margaret Y , Brown Meta S , Naqi Safia
Published: April 2021

The genus Gossypium is favorable for study of genome divergence at several levels. Early stages of divergence have been studied among four D genomes by comparing chiasma frequencies (reciprocal exchanges) between pairs of genomes and between individual counterpart chromosomes marked by heterozygous translocations. D5 (G. raimondii) shows barely detectable differentiation from from Dh (G. hirsutum), whereas D7 (G. lobatum) is considerably less closely related to Dh than is D5. Fragmentary data suggest that D2-2 (G. harknessii) falls between D5 and D7 in its relationship to Dh. Since chiasma frequencies in individual chromosomes and marked regions exhibit the same order of relationships as their corresponding whole genomes, it is concluded that the genome differentiation is generalized (i.e., nucleus-wide) rather than localized in specific chromosomes or chromosome regions. Estimates of relationships based on reciprocal exchange frequencies agree with those based upon preferential synapsis in allohexaploids reported previously. Since preferential synapsis and reciprocal exchange frequencies reveal the same order of relationships, it is concluded that to some extent they reflect common underlying changes in chromosome properties, despite recent evidence that synapsis and crossing over are under independent genetic control.
THE CONSTRUCTION OF RING CHROMOSOMES OF AUTOSOMAL HETEROCHROMATIN IN DROSOPHILA MELANOGASTER
Authors: Hilliker Arthur J
Published: April 2021

The synthesis of ring chromosomes consisting entirely of Drosophila autosomal heterochromatin is described. Our ability to obtain these heterochromatic ring chromosomes from irradiated oocytes is a logical prediction of and constitutes, therefore, a further proof for the translocation model of the origin of compound chromosomes. Additionally, the synthesis of these chromosomes provides us with potentially useful probes for the analysis of the function(s) of Drosophila heterochromatin.
THE NATURE OF GENETIC RECOMBINATION NEAR THE THIRD CHROMOSOME CENTROMERE OF DROSOPHILA MELANOGASTER
Authors: Denell R E , Keppy D O
Published: April 2021

Previous studies have indicated that recombination near the third chromosome centromere is associated with negative chromosome interference, a phenomenon for which GREEN (1975) and SINCLAIR (1975) suggested gene conversion as a possible mechanism. In this report, we demonstrate that negative chromosome interference is still observed when deficiencies or translocation breakpoints are scored as the middle markers in recombination experiments and the rate of recombination is increased by interchromosomal effect. We argue that these chromosomal rearrangement breakpoints are not subject to conversion. Since neither successive premeiotic and meiotic exchanges, nor negative chromatid interference, can by themselves account for the negative chromosome interference, we conclude that a greater than expected frequency of multiple exchanges actually occurs. We further suggest that negative chromosome interference may be characteristic of all chromosomal regions normally showing very little exchange in relation to physical length.
POPULATION GENETICS OF DROSOPHILA NASUTA NASUTA, DROSOPHILA NASUTA ALBOMICANA AND THEIR HYBRIDS. I. KARYOTYPIC MOSAICISM IN THE HYBRID POPULATIONS
Authors: Rajasekarasetty M R , Gowda L Siddaveere , Krishnamurthy N B , Ranganath H A
Published: April 2021

D. n. nasuta and D. n. albomicana constitute a pair of chromosomal races with 2n=8 and 2n=6, respectively. The F1 of these has 2n=7 and it is fertile. There exists a state of karyotypic mosaicism as evidenced by the presence of 26 types of chromosome combinations in F2, F3, and F10 populations. In the midst of this karyotypic noise, the karyotype similar to that of F1 reached 51% of the population. Implications of these findings are discussed.
NEW PROPERTIES OF THE TWO-LOCUS PARTIAL SELFING MODEL WITH SELECTION
Authors: Holden L R
Published: April 2021

Analytic solutions are obtained for the equilibria of a simple two-locus, heterotic selection model with mixed selfing and random outcrossing. T W O general phenomena are possible, depending upon the viabilities and the degree of selfing: (1) Negative disequilibrium potential, under which only gametic disequilibrium is possible; and (2) positive disequilibrium potential, which can result in permanent gametic disequilibrium provided that linkage is sufficiently tight. Under random mating (s = O), these two situations correspond to negative and positive additive epistasis, respectively. With partial self-fertilization, however, this is no longer true, and a more appropriate measure of gametc dis-equilibrium potential, ∆ (s), is introduced. A numerically aided examination of the model results in the discovery of two new properties of partial selfing with selection: (1) With negative disequilibrium potential (∆(s) < 0), the equilibrium mean fitness increases with increasing recombination. With positive disequilibrium potential (∆(s) > 0), the opposite is true. (2) Gametic disequilibrium can increase or decrease as the degree of selfing is increased. Therefore, it is apparent that partial selfing and linkage are not analogous as regards the maintenance of disequilibrium.
THE RATE OF ALLELISM OF LETHAL GENES IN A GEOGRAPHICALLY STRUCTURED POPULATION
Authors: Yokoyama Shozo
Published: April 2021

The expected rate of allelism, E[I(x)], of lethal genes between two colonies with distance x in a structured population is studied by using one-and two-dimensional stepping-stone models. It is shown that E[I(x)] depends on the magnitude of selection in heterozygous condition (h), the rate of migration among adjacent colonies (m), the number of loci which produce lethal mutations (n) and the effective population size of each colony (N).——E[I(x)] always decreases with distance x. The rate of decrease is affected strongly by the magnitude of m. The rate of decrease is faster when m is small. E[I(x)] also decreases with increasing N and n. The effect of h on E[I(x)] is somewhat complicated. However, E[I(O)] is always smaller when h is small than when it is large.——For large x, the following approximate formulae may be obtained: where and Var (q) are the mean and the-variance of gene frequencies in each colony, t is approximated as t = h, 2√u; —h for the partially recessive, completely recessive, and overdominant lethals, respectively, and C  O is a function of m and t. It is clear that E[I(x)] declines exponentially with x in a one-dimensional habitat. The decrease E[I(x)] is faster in a two-dimensional habitat than in a one-dimensional habitat. The present result is applied to some of the existing data and the estimation of population parameters is also discussed.
POLYMORPHISM OF THE HEREDITARY SIGMA VIRUS IN NATURAL POPULATIONS OF DROSOPHILA MELANOGASTER
Authors: Fleuriet Annie
Published: April 2021

Previous studies have shown that, in natural French populations of Drosophila melanogaster, 10 to 20% of the flies are infected by the noncontagious, hereditary rhabdovirus sigma responsible for CO2 sensitivity. These populations are also polymorphic for two alleles [ref(2)Po and ref(2)Pp of a gene for resistance to the sigma virus. Evidence is given here that two viral genetic types, differing in their response to the ref(2)Pp allele, are present in these populations of flies; the most common type is only slightly sensitive to the ref(2)Pp allele.
DEVIATIONS OF GENOTYPIC STRUCTURES FROM HARDY-WEINBERG PROPORTIONS UNDER RANDOM MATING AND DIFFERENTIAL SELECTION BETWEEN THE SEXES
Authors: Ziehe Martin , Gregorius Hans-Rolf
Published: April 2021

Population genetic models, such as differential viability selection between the sexes and differential multiplicative fecundity contributions of the sexes, are considered for a single multiallelic locus. These selection models usually produce deviations of the zygotic genotype frequencies from Hardy-Weinberg proportions. The deviations are investigated (with special emphasis put on equilibrium states) to quantify the effect of selective asymmetry in the two sexes. For many selection regimes, the present results demonstrate a strong affinity of zygotic genotype frequencies for Hardy-Weinberg proportions after two generations, at the latest. It is shown that the deviations of genotypic equilibria from the corresponding Hardy-Weinberg proportions can be expressed and estimated by means of selection components of only that sex with the lower selection intensity. This corresponds to the well-known fact that viability selection acting in only one sex yields Hardy-Weinberg equilibria.
NUCLEOCYTOPLASMIC RELATIONS IN A MUTATOR-SUPPRESSOR SYSTEM OF DROSOPHILA ANANASSAE
Authors: Hinton Claude W
Published: April 2021

A partially characterized mutator-suppressor system, previously identified in the ca; stw stock of Drosophila ananassae, was shown to exist in the ca ancestral stock; it consists of a clastogenic mutator of sperm chromosomes and a supressor that functions in the oöcyte soon after fertilization. Transmission of these components was monitored by Minute mutation frequencies produced by the progeny of recurrently backcrossed hybrid females derived from reciprocal outcrosses of the ca stock. In this way, the mutator was shown to be an extrachromosomally transmitted element whose propagation depends upon nuclear genes. Suppressivity was found to be determined by nuclear genes, some of which are expressed only after a delay of several generations. Neither the mutator nor its suppressor appear to be infectious. Measurement of dominant lethal frequencies showed that the suppressor is completely effective in repair of premutational lesions induced by the mutator. The properties of this mutator-suppressor system were compared with those of hybrid dysgenesis in Drosophila melanogaster.
Effects of 2-D random velocity perturbations on 2-DSHshort-period ground motion simulations in the basin of Nice, France
Authors: Tchawe F N , Gelis C , BONILLA L F , Lopez-Caballero F
Published: April 2021

Some geological configurations, like sedimentary basins, are prone to site effects. Basins are often composed of different geological layers whose properties are generally considered as spatially homogeneous or smoothly varying. In this study, we address the influence of small-scale velocity fluctuations on seismic response. For this purpose, we use the spectral element method to model the 2-D SH wave propagation on a basin of 1.1 km long and ≈ 60 m deep, representing a 2-D profile in the city of Nice, France. The velocity fluctuations are modelled statistically as a random process characterized by a Von Karman autocorrelation function and are superimposed to the deterministic model. We assess the influence of the amplitude and correlation length of the random velocities on the surface ground motion. We vary the autocorrelation function’s parameters and compute seismic wavefields in 10 random realizations of the stochastic models. The analyses of our results focus on the envelope and phase differences between the waveforms computed in the random and deterministic models; on the variability of ground motion intensity measures, such as the peak ground velocity, the pseudo-spectral acceleration response; and the 2-D basin response (transfer function). We find that the amplitude of fluctuations has a greater effect on the ground motion variability than the correlation length. Depending on the random medium realization, the ground motion in one stochastic model can be locally amplified or deamplified with respect to the reference model due to the presence of high or low velocity contrasts, respectively. When computing the mean amplification of different random realizations, the results may be smaller than those of the reference media due to the smoothing effect of the average. This study highlights the importance of knowing the site properties at different scales, particularly at small scales, for proper seismic hazard assessment.
Isotropic and azimuthally anisotropic Rayleigh wave dispersion across the Juan de Fuca and Gorda plates and U.S. Cascadia from earthquake data and ambient noise two- and three-station interferometry
Authors: Zhang Shane , Wang Hongda , Wu Mengyu , Ritzwoller Michael H
Published: April 2021

We use data from the Cascadia Initiative (CI) amphibious array and the USArray Transportable Array to construct and compare Rayleigh wave isotropic and azimuthally anisotropic phase speed maps across the Juan de Fuca and Gorda Plates extending onto the continental northwestern United States. Results from both earthquakes (28–80 s) as well as ambient noise two- and three-station interferometry (10–40 s) are produced. Compared with two-station interferometry, three-station direct wave interferometry provides >50 per cent improvement in the signal-to-noise ratio and the number of dispersion measurements obtained, particularly in the noisier oceanic environment. Earthquake and ambient noise results are complementary in bandwidth and azimuthal coverage, and agree within about twice the estimated uncertainties of each method. We, therefore, combine measurements from the different methods to produce composite results that provide an improved data set in accuracy, resolution and spatial and azimuthal coverage over each individual method. A great variety of both isotropic and azimuthally anisotropic structures are resolved. Across the oceanic plate, fast directions of anisotropy with 180° periodicity (2ψ) generally align with palaeo-spreading directions while 2ψ amplitudes mostly increase with lithospheric age, both displaying substantial variations with depth and age. Strong (>3 per cent) apparent anisotropy with 360° periodicity (1ψ) is observed at long periods (>50 s) surrounding the Cascade Range, probably caused by backscattering from heterogeneous isotropic structures.
Challenging the association between health literacy and health: the role of conversion factors
Authors: Rüegg René , Abel Thomas
Published: April 2021

Previous studies have found substantial correlations between health literacy and various health outcomes. However, the role of social and personal factors in those links remains understudied. Applying a moderation approach, we assume that these factors function as conversion factors on the associations between health literacy and health outcomes. Consequently, we test if associations between health literacy and health outcomes are stronger among young male adults who score high in conversion factors compared to those who score low. Cross-sectional data from the Young Adult Survey Switzerland were used for the analyses (n = 9339, age = 18−25). Multiple logistic regression analyses were applied to estimate associations between health literacy and health. Moderator analyses with three conversion factors and five health outcomes were conducted. For each health outcome at least one conversion factor moderated the association between health literacy and health according to the hypothesis. Although strength and form of the moderation effect differ across analyses, generally stronger associations were found among groups with beneficial social or personal factors. The present findings support the hypothesis that conversion factors play a crucial role in the associations between health literacy and health. The findings, thus, point towards a potential risk of linear health literacy approaches that assume equal benefits from increased health literacy. Individuals with beneficial social and personal factors (those already privileged) may enjoy greater health benefits from interventions improving health literacy.
Outcome analysis of a conservative approach to diaphragmatic paralysis following congenital cardiac surgery in neonates and infants: a bicentric retrospective study
Authors: Denamur Sophie , Chenouard Alexis , Lefort Bruno , Baron Olivier , Neville Paul , Baruteau Alban , Joram Nicolas , Chantreuil Julie , Bourgoin Pierre
Published: April 2021

OBJECTIVES

Diaphragmatic paralysis following congenital cardiac surgery is associated with significant morbidity and mortality. Spontaneous recovery of diaphragmatic function has been described, contrasting with centres providing early diaphragmatic plication. We aimed to describe the outcomes of a conservative approach, as well as to identify factors associated with a failure of the strategy.

METHODS

This is a retrospective study of patients admitted after cardiac surgery and suffering unilateral diaphragmatic paralysis within 2 French Paediatric Cardiac Surgery Centers. The conservative approach, defined by the prolonged use of ventilation until successful weaning from respiratory support, was the primary strategy adopted in both centres. In case of unsuccessful evolution, a diaphragmatic plication was scheduled. Total ventilation time included invasive and non-invasive ventilation. Diaphragm asymmetry was defined by the number of posterior rib segments counted between the 2 hemi-diaphragms on the chest X-ray after cardiac surgery.

RESULTS

Fifty-one neonates and infants were included in the analysis. Patients’ median age was 12.0 days at cardiac surgery (5.0–82.0), and median weight was 3.5 kg (2.8–4.9). The conservative approach was successful for 32/51 patients (63%), whereas 19/51 patients (37%) needed diaphragm plication. There was no difference in patients’ characteristics between groups. Respiratory support prolonged for 21 days or more and diaphragm asymmetry more than 2 rib segments were independently associated with the failure of the conservative strategy [odds ratio (OR) 6.9 (1.29–37.3); P = 0.024 and OR 6.0 (1.4–24.7); P = 0.013, respectively].

CONCLUSIONS

The conservative approach was successful for 63% of the patients. We identified risk factors associated with the strategy’s failure.
Plasmodium malariae and Plasmodium falciparum comparative susceptibility to antimalarial drugs in Mali
Authors: Dembele Laurent , Aniweh Yaw , Diallo Nouhoum , Sogore Fanta , Sangare Cheick Papa Oumar , Haidara Aboubecrin Sedhigh , Traore Aliou , Diakité Seidina A S , Diakite Mahamadou , Campo Brice , Awandare Gordon A , Djimde Abdoulaye A
Published: April 2021

Objectives

To evaluate Plasmodium malariae susceptibility to current and lead candidate antimalarial drugs.

Methods

We conducted cross-sectional screening and detection of all Plasmodium species malaria cases, which were nested within a longitudinal prospective study, and an ex vivo assessment of efficacy of a panel of antimalarials against P. malariae and Plasmodium falciparum, both PCR-confirmed mono-infections. Reference compounds tested included chloroquine, lumefantrine, artemether and piperaquine, while candidate antimalarials included the imidazolopiperazine GNF179, a close analogue of KAF156, and the Plasmodium phosphatidylinositol-4-OH kinase (PI4K)-specific inhibitor KDU691.

Results

We report a high frequency (3%–15%) of P. malariae infections with a significant reduction in ex vivo susceptibility to chloroquine, lumefantrine and artemether, which are the current frontline drugs against P. malariae infections. Unlike these compounds, potent inhibition of P. malariae and P. falciparum was observed with piperaquine exposure. Furthermore, we evaluated advanced lead antimalarial compounds. In this regard, we identified strong inhibition of P. malariae using GNF179, a close analogue of KAF156 imidazolopiperazines, which is a novel class of antimalarial drug currently in clinical Phase IIb testing. Finally, in addition to GNF179, we demonstrated that the Plasmodium PI4K-specific inhibitor KDU691 is highly inhibitory against P. malariae and P. falciparum.

Conclusions

Our data indicated that chloroquine, lumefantrine and artemether may not be suitable for the treatment of P. malariae infections and the potential of piperaquine, as well as new antimalarials imidazolopiperazines and PI4K-specific inhibitor, for P. malariae cure.
Association between limiting the number of open records in a tele-critical care setting and retract–reorder errors
Authors: Udeh Chiedozie , Canfield Christina , Briskin Isaac , Hamilton Aaron C
Published: April 2021

Background

Wrong patient selection errors may be tracked by retract–reorder (RAR) events. The aim of this quality improvement study was to assess the impact of reducing the number of concurrently open electronic health records from 4 to 2 on RAR errors generated by a tele-critical care service.

Methods

The study encompassed 32 months before and 21 months after restriction. Chi-Square test of proportions and T statistical process control chart for rare events were used.

Results

There were 156 318 orders with 57 RAR errors (36.5/100 000 orders) before restriction, and 122 587 orders with 34 errors (27.7/100 000 orders) after. Rates were not statistically different (P = .20), but analysis was underpowered. When plotted on a T control chart, random variation was detected between RAR errors.

Conclusion

We found no significant difference in RAR errors in the tele-critical care setting after open record limitation. Other strategies should be studied to reduce wrong patient selection errors.
Bile acid sequestrants: a review of mechanism and design
Authors: Feng Yumiao , Li Qian , Ou Ge , Yang Meiyan , Du Lina
Published: April 2021

Objective

Bile acid sequestrants (BAS) are used extensively in the treatment of hypercholesterolaemia. This brief review aimed to describe the design and evaluation of three types of BAS: amphiphilic copolymers, cyclodextrin/poly-cyclodextrin and molecular imprinted polymers. The mechanisms underlying the action of BAS are also discussed.

Key findings

BAS could lower plasma cholesterol, improve glycemic control in patients with type 2 diabetes and regulate balance energy metabolism via receptors or receptor-independent mediated mechanisms. Different types of BAS have different levels of ability to bind to bile acids, different stability and different in-vivo activity.

Conclusions

A growing amount of evidence suggests that bile acids play important roles not only in lipid metabolism but also in glucose metabolism. The higher selectivity, specificity, stability and in-vivo activity of BAS show considerable potential for lipid-lowering therapy.
Pepper E3 ligase CaAIRE1 promotes ABA sensitivity and drought tolerance by degradation of protein phosphatase CaAITP1
Authors: Baek Woonhee , Lim Chae Woo , Lee Sung Chul
Published: April 2021

Plants have developed defense mechanisms to survive in extreme environmental conditions. Abscisic acid (ABA) is a key phytohormone associated with plant adaptation to environmental stress. In this study, we isolated and functionally characterized the pepper RING-type E3 ligase CaAIRE1 (Capsicum annuum ABA Induced RING-type E3 ligase 1) containing the C3HC4-type RING domain. CaAIRE1 was induced by ABA and drought, and CaAIRE1 had E3 ligase activity. CaAIRE1-silenced pepper and CaAIRE1-overexpressing Arabidopsis presented drought-sensitive and drought-tolerant phenotypes, respectively, which were accompanied by altered transpiration water loss and ABA sensitivity. Moreover, we found that CaAIRE1 interacts with and ubiquitinates the pepper type 2C protein phosphatase, CaAITP1 (Capsicum annuum CaAIRE1 Interacting Target Phosphatase 1). A cell-free degradation assay with CaAIRE1-silenced peppers and CaAIRE1-overexpressing Arabidopsis plants revealed that the CaAITP1 protein level was negatively modulated by the expression level of CaAIRE1. In contrast to CaAIRE1, CaAITP1-silenced pepper showed ABA-sensitivity phenotypes. CaAITP1-overexpressing Arabidopsis plants were the most insensitive phenotypes to ABA compared with the wild type and other pepper PP2C-overexpressing plants. Taken together, our data indicate that CaAITP1 plays a major role as a negative modulator in ABA signaling, and CaAIRE1 regulates the ABA signaling and drought response through modulation of CaAITP1 stability.
MiR-150 Expression in Chronic Myeloid Leukemia: Relation to Imatinib Response
Authors: Habib Eman M , Nosiar Nahla A , Eid Manal A , Taha Atef M , Sherief Dalia E , Hassan Asmaa E , Abdel Ghafar Muhammad T
Published: April 2021

Objective

To assess the circulating micro-RNA-150 (miR-150) expression in patients with chronic myeloid leukemia (CML) in relation to imatinib response.

Methods

Sixty patients with CML and 20 age- and sex-matched control subjects were enrolled. Circulating miR-150 levels were assessed by quantitative real-time polymerase chain reaction on days 0, 14, and 90 of imatinib therapy for patients and once for control subjects.

Results

The baseline miR-150 expression was significantly lower in patients with CML than in control subjects with subsequent elevation at 14 and 90 days after the start of imatinib treatment. Early treatment response (ETR) at 90 days was the main study outcome. The miR-150 expression had a significantly higher level in patients with CML with ETR. On multivariate analysis, miR-150 on day 14 was significantly related to ETR in patients with CML with predictive efficacy (area under the curve = 0.838, 72.9% sensitivity, and 84.2% specificity).

Conclusion

We found that miR-150 expression on day 14 of imatinib treatment is a useful early predictive candidate for imatinib response in patients with CML.
Fundamental mechanism of the creation of chemical bimodality in the Milky Way disc in the cold accretion theory
Authors: Noguchi Masafumi
Published: April 2021

Chemical bimodality of the Milky Way (MW) disc stars constitutes one of the most remarkable properties of MW. The cold accretion theory for the cosmological gas accretion provides one viable explanation to this phenomenon. In this scenario, the rapid cold-mode accretion in the early epoch creates the first generation stars relatively rich in α-elements (O, Mg, Si, S, Ca, etc) and later cooling flow produces iron-rich second generation stars, creating the bimodality in the [α/Fe] ratio. We employ a cosmologically motivated chemical evolution model for disc galaxies to elucidate the role played by type Ia supernovae (SN Ia), which serve as the major source of iron, in the creation of the bimodality. To this end, we divide SN Ia into two groups, those formed from the 1st generation stars (the first SN Ia) and those formed from the 2nd generation stars (the second SN Ia). The model with the first SN Ia suppressed during the second star formation stage produces stars having high [α/Fe] in the early phase of this stage, whereas the model which prohibits the second SN Ia produces high [α/Fe] stars in the late phase. Both models fail to create a well-defined bimodality. We, thus, conclude that the cooperation of the first and the second SN Ia plays a crucial role in creating the bimodality by maintaining rich iron content in the interstellar gas throughout the second star formation stage.
Unraveling the inner substructure of new candidate hub-filament system in the H ii region G25.4NW
Authors: Dewangan L K
Published: April 2021

We present multiscale and multiwavelength data of the Galactic H ii region G25.4−0.14 (hereafter G25.4NW, distance ∼5.7 kpc). The SHARC-II 350-μm continuum map displays a hub-filament configuration containing five parsec-scale filaments and a central compact hub. Through the 5-GHz radio continuum map, four ionized clumps (i.e. Ia–Id) are identified towards the central hub, and are powered by massive OB-stars. The Herschel temperature map depicts the warm dust emission (i.e. T$_{\rm d}\, \sim$23–39 K) towards the hub. High-resolution Atacama Large Millimeter/submillimeter Array (ALMA) 1.3-mm continuum map (resolution ∼0.82 × 0.58 arcsec2) reveals three cores (c1–c3; mass ∼80–130 M⊙) towards the ionized clumps Ia, and another one (c4; mass ∼70 M⊙) towards the ionized clump Ib. A compact near-infrared (NIR) emission feature (extent ∼0.2 pc) is investigated towards the ionized clump Ia excited by an O8V-type star, and contains at least three embedded K-band stars. In the direction of the ionized clump Ia, the ALMA map also shows an elongated feature (extent ∼0.2 pc) hosting the cores c1–c3. All these findings together illustrate the existence of a small cluster of massive stars in the central hub. Considering the detection of the hub-filament morphology and the spatial locations of the mm cores, a global non-isotropic collapse (GNIC) scenario appears to be applicable in G25.4NW, which includes the basic ingredients of the global hierarchical collapse and clump-fed accretion models. Overall, the GNIC scenario explains the birth of massive stars in G25.4NW.
A generative model of galactic dust emission using variational autoencoders
Authors: Thorne Ben , Knox Lloyd , Prabhu Karthik
Published: April 2021

Emission from the interstellar medium can be a significant contaminant of measurements of the intensity and polarization of the cosmic microwave background (CMB). For planning CMB observations, and for optimizing foreground-cleaning algorithms, a description of the statistical properties of such emission can be helpful. Here, we examine a machine learning approach to inferring the statistical properties of dust from observational data. In particular, we apply a type of neural network called a variational autoencoder (VAE) to maps of the intensity of emission from interstellar dust as inferred from Planck sky maps and demonstrate its ability to (i) simulate new samples with similar summary statistics as the training set, (ii) provide fits to emission maps withheld from the training set, and (iii) produce constrained realizations. We find VAEs are easier to train than another popular architecture: that of generative adversarial networks, and are better suited for use in Bayesian inference.
Temporal evolution of prompt GRB polarization
Authors: Gill Ramandeep , Granot Jonathan
Published: April 2021

The dominant radiation mechanism that produces the prompt emission in gamma-ray bursts (GRBs) remains a major open question. Spectral information alone has proven insufficient in elucidating its nature. Time-resolved linear polarization has the potential to distinguish between popular emission mechanisms, e.g. synchrotron radiation from electrons with a power-law energy distribution or inverse Compton scattering of soft seed thermal photons, which can yield the typical GRB spectrum but produce different levels of polarization. Furthermore, it can be used to learn about the outflow’s composition (i.e. whether it is kinetic-energy-dominated or Poynting-flux-dominated) and angular structure. For synchrotron emission, it is a powerful probe of the magnetic field geometry. Here, we consider synchrotron emission from a thin ultrarelativistic outflow, with bulk Lorentz factor Γ(R) = Γ0(R/R0)−m/2 ≫ 1, that radiates a Band-function spectrum in a single (multiple) pulse(s) over a range of radii, R0 ≤ R ≤ R0 + ΔR. Pulse profiles and polarization evolution at a given energy are presented for a coasting (m = 0) and accelerating (m = −2/3) thin spherical shell and for different viewing angles for a top-hat jet with sharp as well as smooth edges in emissivity. Four different magnetic field configurations are considered, such as a locally ordered field coherent over angular scales θB ≳ 1/Γ, a tangled field (B⊥) in the plane transverse to the radial direction, an ordered field (B∥) aligned in the radial direction, and a globally ordered toroidal field (Btor). All field configurations produce distinct polarization evolution with single (for B⊥ and B∥) and double (for Btor) 90○ changes in the polarization position angle.