bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of temperature on subclinical infection by Batrachochytrium dendrobatidis in three species of plethodontid salamanders
Authors: Mendoza-Almeralla Cinthya , Suazo-Ortuño Ireri , Parra-Olea Gabriela , Suzán Gerardo
Published: January 2021

We assessed the effect of temperature on subclinical Batrachochytrium dendrobatidis (Bd) infection in three species of plethodontids. Collected individuals were tested for Bd in the field during the dry and rainy season and randomly assigned to 15° and 18°C treatments for 30 days. We collected 129 salamanders, of these nine individuals tested positive for Bd in the field. At the two temperature trials, 12 individuals that were Bd-negative in the field, tested positive for Bd. Near the end of the temperature trials, 18 of 21 Bd-positive individuals tested negative for Bd. Three individuals that were Bd positive in the field and assigned to the 18°C trial died during the experiment. Our results suggest that at 15°C the most of plethodontids present subclinical infection, whereas at higher temperatures, Bd infection can increase to detectable levels. The processes underlying plethodontids’s recovery from Bd infection warrants further study.
No Sense in Saying ‘There is No Sense Organ for Time’
Authors: Singhal Ishan
Published: January 2021

This paper explores the use of perhaps the most ubiquitous phrase in time perception literature, i.e., ‘there is no sense organ for time’. I argue here that its usage often highlights several misguided notions about how we perceive time and thus creates a problem in studying it. In this commentary three such underlying notions are discussed which are often drawn as conclusions from the lack of a sensory system to perceive time. These are that time is generated or created separately by the brain, that time perception is different from other kinds of perception and that the study of time is hampered by the lack of a dedicated sense organ. These notions are discussed and argued against. It is claimed that a sense organ for time is not possible, nor does this exclude time from our percepts in general. Moreover, rather than creating a problem, a lack of a sense organ for time offers an opportunity to theorize about our experiences across perceptual modalities and cognitive mechanisms. I conclude by suggesting an end to using this phrase and instead seeing mental time as existing across our experiences.
On the problematic placement of the fossil arthropod Devonopilio hutchinsoni in Opiliones (Arachnida)
Authors: PÉREZ-GONZÁLEZ ABEL , SHULTZ JEFFREY W.
Published: January 2021

Harvestmen (Arachnida: Opiliones) were among the earliest terrestrial arthropods but their unmineralized exoskeletons are scarce and often fragmentary as fossils (Palencia et al. 2019). Consequently, the discovery and interpretations of fossil harvestmen from the early Palaeozoic can have disproportionate effects on the understanding of evolution in Opiliones. Recently, Devonopilio hutchinsoni Tihelka, Tian & Cai, 2020, was described as a new fossil harvestman from the well-known Rhynie chert deposits of Scotland, an important source of information on freshwater and terrestrial ecosystems of the early Devonian (Tihelka et al. 2020). This species would be one of the earliest records of harvestmen. The description was based on a single slide showing fragments of arthropod cuticle, which Tihelka et al. interpreted as a harvestmen penis and unspecified associated body parts. As specialists on harvestman morphology and systematics, we were intrigued by these conclusions. However, based on the material presented by Tihelka et al. we find no compelling evidence supporting the proposal that the specimen is a harvestman.
A new species of Protoplotina Miyatake (Coleoptera: Coccinellidae) from Tamil Nadu, India
Authors: POORANI J. , ANURADHA C. , THANIGAIRAJ R.
Published: January 2021

Protoplotina ambigua sp. n. (Coccinellidae: Plotinini) from the southern Indian state of Tamil Nadu is described and illustrated. This is the third species of the genus reported from India. Immature stages of the genus Protoplotina are briefly described and illustrated for the first time with notes on host association. A revised key to the known species of the genus is also included.
Green Synthesis of Iron Nanoparticles by a Polysaccharide Bioflocculant from Marine Alcaligenes faecalis HCB2 and Characterization
Authors: Dlamini Nkosinathi G. , Basson Albertus K. , Pullabhotla Rajasekhar V. S. R.
Published: January 2021

Iron, the most ubiquitous of the transition metals and the fourth most plentiful metal in the Earth’s crust, is the structural backbone of our modern infrastructure. It is therefore ironic that as a nanoparticle, iron has been somewhat neglected in favour of its own oxides as
well as other metals such as cobalt, nickel, gold, and platinum. This study reports the green synthesis of iron nanoparticles using a bioflocculant and their characterization. The as-synthesised materials were characterized using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy
(TEM), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric analysis (TGA) and UV-Vis absorption spectroscopy. Spherical morphology was observed for the as-synthesised iron nanoparticles (FeNPs) and elemental analysis indicated iron with 17.31%. XRD studies
revealed the broader peaks at 24°, 29°, 30°, and 35° 2θ for the as-synthesised iron nanoparticles indicating the nano sized particles. FT-IR spectra showed the bands at 3154 cm-1 (bioflocculant) and 3244 cm-1 (iron nanoparticles) representing the
presence of hydroxyl (–OH) and amine (–NH2) functional groups.
Positioning Effect on Free Convection with an Elliptical Plate Placed in a Circular Enclosure
Authors: Patpatiya Parth , Soumya  , Shaan Bhavya , Yadav Bhavana
Published: January 2021

In this analysis we have examined the process of the steady state laminar natural convection around heated elliptical plate with Rayleigh number 10^6 positioned inside a circular enclosure. The purpose of the numerical analysis is to analyze the behavior of isotherms, streamlines and
heat transfer rate in enclosure plate system due to the variation in the position of elliptical plate (r/D =0.00, 0.05, and 0.2) and aspect ratio, where the given diameter of the enclosure is D and r is the distance between the centre of elliptical plate and centre of
circle. Elliptical plate is inclined at different angles and results are summed up in relative manner. There are two cases, in first case aspect ratio a/D and b/D is varied and D is kept constant, whereas in second case aspect ratio a/D and b/D is kept constant
and D is varied. Temperature difference between the enclosure and the inner body (i.e., temperature of inner body is kept high as compared to the enclosure) is maintained. Two dimensional study is followed by considering air as a fluid in enclosure. The effects of the Heat Transfer
and Flow of Fluid are analyzed by the streamlines and isotherms plotted for the body placed inside enclosure. Value of local Nusselt number (Nu) is also plotted along the wall of elliptical plate and along the surface of the circular enclosure. For every aspect ratio isotherms and streamlines
had been plotted. This work has been validated with various other numerical studies and was in good conciliation.
Microstructural and Mechanical Characterizations of Chromium Carbides and Chromium Borides Layers Over Low-Carbon Steel Surface
Authors: Boubaaya Rabah , Allaoui Omar , Benarioua Younes , Djendel Mokhtar
Published: January 2021

Hard coatings based on chromium carbides and chromium borides are widely used in applications that require mechanical performance, i.e., high hardness and low friction coefficient and good corrosion resistance. In this work, we made layers of chromium carbides and chromium borides on
the surface of low carbon steel through some specific treatments. For chromium carbides, the cementation in a solid medium followed by electroplating of chromium on the surface and finally the application of annealing treatment at temperatures between 500 and 1100 °C for 1 hour. For chromium
borides, the boriding treatment in solid medium at 900 °C for 4 hours followed by chromium electroplating on the steel surface and finally the application of annealing treatment at temperatures at 950 °C for 1 and 2 hours. The obtained results show that, in the first case, the cemented
layer and the chromium deposited on the surface combine to form chromium carbides on the treated surface after annealing. Similarly, for the second case, boron diffusion and chromium deposition lead to chromium borides on the treated surface. The characteristics of the chromium carbides and
chromium borides obtained are very similar to those of chromium carbides and chromium borides obtained by other processes.
Neural Learning Controller with Tracking Differentiator
Authors: Zhang Zhihuan , Hu Chao
Published: January 2021

It is well known that the closed-loop dynamic quality of the conventional PID correction system is too sensitive to the change of the PID gain value. When the controlled plant is in a changing environment, it is necessary to change the gain according to the plant change in the environment.
In addition, when the input signal contains noise, the differentiator in traditional PID control can easily lead to serious noise amplification effect. In view of the above shortcomings, a neuron learning controller with tracking differentiator is proposed, which can reduce the noise of input
signal and change the gain of PID according to the change of the environment of the controlled plant. The simulation results show the effectiveness of the algorithm.
Improvement of Gamma Radiation Shielding Features for Fluorophosphate Glasses Doping with Sm2O3 (PZBKNA)
Authors: Almohiy H. , Saad M. , AbouDeif Y. M. , Grelowska Iwona , Reben M. , Yaha I. S. , Yousef El Sayed
Published: January 2021

This research reported on the radiation safety characteristics of doped fluorophosphate glasses with heavy rare earth lanthanide (Sm2O3) in the composition 40P2O5/30ZnO/20BaF2/3.8K2TeO3/1.2Al2O3/5.0Nb2O5/30000
ppm Sm2O3 and 40P2O5/30ZnO/20BaF2/3.8K2TeO3/1.2Al2O3/5.0Nb2O5/40000 ppm Sm2O3 in mol%. The parameters for shielding like that mass attenuation coefficient,
MAC, linear attenuation coefficient, LAC, tenth value layers, TVL, half-value layers, HVL, effective atomic number, (Zeff), mean free path, MFP, electron density, Neff, electronic cross-sections, ECS, and total atomic cross-sections, ACS, were calculated between 0.015 and 15 MB of preparation
glasses. The protection parameters of the current glasses are good in comparison to industrial materials used for nuclear shieldings, such as glass RS 253, ordinary concrete (OC), hematite serpenite (HS), or basalt magnet (BM). From the above mention results, the prepared glasses can be used
as radiation safety materials.
Theoretical Study of a Novel Infrared Nonlinear Optical Crystal of BaGa4S7
Authors: Wu Qiao , Dai Rong , Zhang Lei , Wang Wei , Zhang Fuchun , Zhang Weibin
Published: January 2021

The first-principles calculation based on density functional theory, the electronic structure and optical properties of BaGa4S7 (BGS) were systematically investigated by using generalized gradient approximation (GGAPBE) and hybrid functional method (HSE06). The
results showed that the theoretical results from the HSE06 method coincided well with the experimental values. Geometry optimization showed that the theoretical lattice parameters of the BGS were also in agreement with the experimental values. Furthermore, the results of the electronic structure
showed that the BGS is a nonlinear optical crystal with a wide direct bandgap energy value, as the bandgap width obtained by the HSE06 method was 3.54 eV, which was in accordance with the experimental values. The band structure and density values of state calculations showed that the top of
the valence band was mainly composed of S-3p orbital and Ga-4s, 4p orbital electron contribution. On the other hand, the bottom of the conduction band was mainly composed of Ga-4s, 4p, S-3p, and Ba-5d orbital electron contribution, showing that
the orbital coupling between Ga and S atoms determined the optical properties of the BGS, while the contribution of Ba atoms to the optical properties was small. The optical properties obtained from the calculation results showed that the crystal material had strong absorption and reflection
characteristics in the ultraviolet band, good transmittance in the infrared area, average static dielectric constant, and an average refractive index of 2.873, 1.69, respectively. Moreover, the static double refractive index was 0.07, showing that BGS crystal materials had excellent phase
matching performance in a wider range of wavelengths, with a high laser damage threshold. These results proved that the BGS could be a promising material for IR nonlinear optical crystals.
High Performance Novel Gas Sensor Device for Site Environmental Protection Using Ti0.5Sn0.5O2 Nanomaterials
Authors: Zhou Mingliang , Chen Xuhong , Zhang Lingjiang , Zeng Wen
Published: January 2021

SnO2 and TiO2 have attracted the most attention due to their unique chemical and electrical properties in basic research of functional materials and applied research of materials. The performance of composite oxide or solid solution material is better than that
of monomer oxide. Therefore, SnO2?TiO2 composite oxide system has become one of the active composite materials studied at home and Abroad. A large number of reports have shown that a certain proportion of SnO2?TiO2 composite material can obtain the
best gas-sensitive performance, but this proportion has a great relationship with the crystal structure and process conditions of the material preparation. Therefore, in this paper, Ti0.5Sn0.5O2 solid solution materials with Sn/Ti molar ratio of 1/1 were prepared
at different sintering temperatures, and their structure and gas-sensitive properties were studied. After sintering at 650 °C, the samples were mainly closely combined with rutile SnO2 and anatase type TiO2 particles, and some Sn and Ti ions were replaced. After sintering
at 1050 °C, the composite mode of SnO2/TiO2 was dominated by solid solution and rutile Ti?Sn?O2 solid solution. The samples prepared at different sintering temperatures have different gas-sensitive properties for methanol, ethanol and other organic gases
and the gas-sensitive properties of the prepared SnO2?TiO2 composite decreased with the increase of sintering temperature.
Analysis of Longitudinal Wave Propagation in a Single-Walled Carbon Nanotube with Surface Irregularity via Donnell Thin Shell Approach
Authors: Mousa Awad , Selim Mahmoud. M.
Published: January 2021

In the reinforcement of the structure of carbon nanotubes, irregularities may occur as consequences of manufacturing defect, servicing reckless, environmental damages, etc. Hence, it is of great importance to deal with various constructions of single-walled carbon nanotubes to study
wave propagation. This study is the first attempt to show the impacts of the surface irregularity on waves propagating in a single-walled carbon nanotube (SWCNT) using Donnell thin shell approach. A new closed-form of the characteristics equation is derived. The results show that, the presence
of surface irregularities effects the natural frequency of longitudinal waves propagating in the single-walled carbon nanotubes. In this work, the theoretical investigation and numerical results are important to predict the phenomenon of wave propagation in irregular single-walled carbon nanotubes,
which can be used as a useful reference for the designs of Nano drive devices, Nano oscillators and Nano sensors.
Magnetic Nanostructures Immobilized Microorganisms for the Development of Nano-Biofertilizers
Authors: Kumar Shalendra , Dwivedi Sourabh , Ahmed Faheem , Shaalan Nagih M. , Arshi Nishat , Alshoaibi Adil , Rauf Mohd Ahmar
Published: January 2021

In this manuscript, Fe3O4 nanoparticles (NPs) were prepared by using a simple cost-effective domestic microware based chemical route. The Crystal structure of Fe3O4 nanoparticles studied using X-ray diffraction and selective area electron
diffraction pattern clearly showed that Fe3O4 NPs exhibited single-phase FCC structures. The average crystallite size calculated using the XRD pattern and TEM micrographs was found to be ∼7 and ∼12 nm, respectively. The magnetic hysteresis loop measured at room
temperature inferred that Fe3O4 NPs exhibited the soft ferromagnetic behavior. The nanoparticles then immobilized with Pseudomonas aeruginosa strain JS11. Bacteria have contemporaneous plant growth and biocontrol potential viz indole acetic acid (IAA) production,
tri-calcium phosphate solubilization in Pikovskaya’s medium. These auxiliary activities of strain showed remarkable capability in the presence of Fe3O4 NPs at different concentrations. The IAA assay revealed the presence of Fe3O4 NPs (50 and
100 ng mL-1) increased the production of about 26.1 and 27.9 μg mL-1 of IAA, respectively, as compared to 22 μg mL-1 IAA in the medium. Phosphate solubilization also increased in the presence of Fe3O4 NPs 100 ng‘mL-1
as compared to the control. Production of siderophores and antibiotic phenazine-1-carboxylic acid (PCA) production in bacterial cell culture was determined. Thus, the increase in auxiliary biological activities viz. IAA production, phosphate solubilization, siderophores, and PCA production
in the presence of Fe3O4 NP stratifies the better plant growth and biocontrol activities in agricultural soils.
Analysis of Nano-Silver Application in Nasosinusitis and Its Effect on Eotaxin
Authors: Ouyang Zhiguo , Wu Xiaohong
Published: January 2021

Nasosinusitis (NA) is a severe inflammatory disease. In recent years, NA’s morbidity and its threat to patients is becoming increasingly serious. Clinically, it is considered that NA recurrence and refractoriness is due to eosinophil (EO) proliferation. Nanotechnology improvement
and application is a breakthrough in diagnosing and treating clinical diseases. Among which, nano-silver (NNS) technology is consistent with effective NA treatment, but there is no reliable research demonstrating this. In this study, inflammatory factors, EO chemokines, and epidermal growth
factors (EGF) in NNS-treated NA mice were analyzed to determine whether NNS had a potential therapeutic effect on NA. The results showed the clinical NA symptom score in mice decreased (P <0.05). Inflammatory factors in nasal lavage fluid (NLF), as well as NF-κB and
eotaxin in the maxillary sinus mucosa were inhibited (P <0.05). Finally, EGF and epidermal growth factor receptor increased (P <0.05). These data demonstrate that NNS is an effective NA treatment. NNS may be able to reduce the cell inflammation occurrence and development
by inhibiting EO chemokine expression, and promoting certain repair programs to the damaged nasal mucosa. There, NNS may become a feasible scheme for future NA treatment.
Global Surface Temperature Response to 11-Yr Solar Cycle Forcing Consistent with General Circulation Model Results
Authors: Amdur T. , Stine A. R. , Huybers P.
Published: January 2021

The 11-yr solar cycle is associated with a roughly 1 W m−2 trough-to-peak variation in total solar irradiance and is expected to produce a global temperature response. The sensitivity of this response is, however, contentious. Empirical best estimates of global surface temperature sensitivity to solar forcing range from 0.08 to 0.18 K (W m−2)−1. In comparison, best estimates from general circulation models forced by solar variability range between 0.03 and 0.07 K (W m−2)−1, prompting speculation that physical mechanisms not included in general circulation models may amplify responses to solar variability. Using a lagged multiple linear regression method, we find a sensitivity of global-average surface temperature ranging between 0.02 and 0.09 K (W m−2)−1, depending on which predictor and temperature datasets are used. On the basis of likelihood maximization, we give a best estimate of the sensitivity to solar variability of 0.05 K (W m−2)−1 (0.03–0.09 K; 95% confidence interval). Furthermore, through updating a widely used compositing approach to incorporate recent observations, we revise prior global temperature sensitivity best estimates of 0.12–0.18 K (W m−2)−1 downward to 0.07–0.10 K (W m−2)−1. The finding of a most likely global temperature response of 0.05 K (W m−2)−1 supports a relatively modest role for solar cycle variability in driving global surface temperature variations over the twentieth century and removes the need to invoke processes that amplify the response relative to that exhibited in general circulation models.
Track Dependence of Tropical Cyclone Intensity Forecast Errors in the COAMPS-TC Model
Authors: Kieu Chanh , Evans Cole , Jin Yi , Doyle James D. , Jin Hao , Moskaitis Jonathan
Published: January 2021

This study examines the dependence of tropical cyclone (TC) intensity forecast errors on track forecast errors in the Coupled Ocean–Atmosphere Mesoscale Prediction System for Tropical Cyclones (COAMPS-TC) model. Using real-time forecasts and retrospective experiments during 2015–18, verification of TC intensity errors conditioned on different 5-day track error thresholds shows that reducing the 5-day track errors by 50%–70% can help reduce the absolute intensity errors by 18%–20% in the 2018 version of the COAMPS-TC model. Such impacts of track errors on the TC intensity errors are most persistent at 4–5-day lead times in all three major ocean basins, indicating a significant control of global models on the forecast skill of the COAMPS-TC model. It is of interest to find, however, that lowering the 5-day track errors below 80 n mi (1 n mi = 1.852 km) does not reduce TC absolute intensity errors further. Instead, the 4–5-day intensity errors appear to be saturated at around 10–12 kt (1 kt ≈ 0.51 m s−1) for cases with small track errors, thus suggesting the existence of some inherent intensity errors in regional models. Additional idealized simulations under a perfect model scenario reveal that the COAMPS-TC model possesses an intrinsic intensity variation at the TC mature stage in the range of 4–5 kt, regardless of the large-scale environment. Such intrinsic intensity variability in the COAMPS-TC model highlights the importance of potential chaotic TC dynamics, rather than model deficiencies, in determining TC intensity errors at 4–5-day lead times. These results suggest a fundamental limit in the improvement of TC intensity forecasts by numerical models that one should consider in future model development and evaluation.
Measuring the Hidden Numbers of Human Trafficking Through Multiple Systems Estimation: Lessons Learned and Challenges Outstanding
Authors: Durgana Davina , van Dijk Jan
Published: January 2021

This article takes stock of studies conducted in eight countries to estimate the prevalence of human trafficking by employing the technique of Multiple Systems Estimation on data on victims of human trafficking recorded by state and non-state institutions. It presents an overview of MSE-based prevalence estimates of human trafficking victims per 100,000 inhabitants of these countries, disaggregated by type of exploitation, gender, and age. For some countries it also presents the different likelihoods of various sub-categories of trafficking victims, such as minors and migrant workers, to be detected by authorities and/or NGOs. Next, the article recounts what these studies have taught us about the suitability of applying MSE on existing multi-source databases to estimate the prevalence of trafficking victimization. The article concludes with a discussion on the promises and limitations of MSE and its prospects for further development, especially among developed nations.
A cascade of exclusion: administrative burdens and access to citizenship in the case of Argentina’s National Identity Document
Authors: Chudnovsky Mariana , Peeters Rik
Published: January 2021

Administrative burdens can hinder people’s social, political and economic participation. However, most empirical studies usually tackle the issue of how they affect access to citizenship merely indirectly. This article examines administrative exclusion from Argentina’s National Identity Document and its effects on a key social policy: the Universal Child Allowance. Findings indicate that: (1) administrative exclusion from official identity documents ‘feeds back’ into the construction of a vulnerable target group that is systematically excluded from social benefits and public services; and (2) limitations in the administrative capacity for identity registration and documentation ‘trickle down’ to complications in the implementation of social policies as target groups remain ‘off the radar’. Findings also demonstrate the importance of understanding administrative burdens as a systemic issue. Burdens manifest themselves at the level of citizen–state interactions but their causes and consequences are tied up with intractable institutional characteristics, administrative capacities and social inequalities.

Points for practitioners

Efforts by developing countries to develop effective social protection systems are often thwarted by limitations in the state’s capacity to identify and reach marginalized citizens. This suggests the need for a systemic perspective of the state’s entire capacity instead of merely focusing on the design of social protection programmes. Specifically, we demonstrate that complete, accessible and up-to-date civil registries, identity documents and other forms of registration are a precondition for transforming formal rights into a tangible reality for citizens.
Optimization of process parameters of recycled carbon fiber-reinforced thermoplastic prepared by the wet-laid hybrid nonwoven process
Authors: Yan Xin , Wang Xiwen , Yang Jin , Zhao Guanglei
Published: January 2021

The wet-laid hybrid nonwoven process can produce affordable carbon fiber-reinforced thermoplastic (CFRTP) because of its process simplicity, which can promote the application of CFRTP products in automobile weight reduction. The wet-laid hybrid nonwoven process involves two procedures, mainly: prepare preforms by a papermaking-like process and heat-molding compression. The parameters of heat-molding compression affect the quality of CFRTP directly, but there are not enough researches focusing on the effects of heat-molding compression parameters. This study aims to optimize the wet-laid hybrid nonwoven process to prepare recycled CFRTP. A proper carbon fiber content was determined firstly. Then, response surface methodology was used to optimize the heat-molding compression parameters. The effects of fiber length on composite properties were also investigated. The results showed that the fiber content of 30 wt% was the most suitable. The optimized heat-molding conditions were temperature, pressure, and time of 190°C, 2 MPa, and 10 min, respectively, leading to the lowest void content of 0.9%. CFRTP comprising carbon fibers with a length of 6 mm had the best properties, with the tensile strength of 59.34 MPa and flexural strength of 145.91 MPa.
Associations of Insomnia Symptoms With Cognition in Persons With Heart Failure
Authors: Gharzeddine Rida , Yu Gary , McCarthy Margaret M. , Dickson Victoria Vaughan
Published: January 2021

Although cognitive impairment is common among persons with heart failure and negatively impacts self-care, hospitalization, and mortality, the associations between cognitive impairment and insomnia symptoms are not clearly understood. The purpose of this study was to explore these associations and examine if they are maintained after adjusting for relevant sociodemographic, clinical, and lifestyle factors. Guided by the Neurocognitive model of insomnia and sleep and the self-care conceptual model, a cross-sectional data analysis using parametric testing was conducted on the Health and Retirement Study wave 2016. Difficulty initiating sleep and early morning awakening, but not difficulty maintaining sleep were significantly associated with poorer cognitive performance in the bivariate and multivariate analysis. Our results are suggestive of different phenotypes of insomnia symptoms that may have different associations with cognition in persons with heart failure. Further research using objective measurements of insomnia symptoms and detailed neuropsychiatric testing of cognition is needed to confirm this conclusion.
Influence of carbon nanotubes on the properties of biopolyol based polyurethane foams
Authors: Dhoke Rujuta , Ojha Abhishek , Chaudhary Ashutosh Kr , Vijayakumar RP
Published: January 2021

Biopolyols were obtained from liquefaction of sugarcane bagasse and rice husk. Acid and hydroxyl numbers were determined for estimating the polyol value of the liquid products. These prepared biopolyols were mixed with the commercial polyol for the preparation of polyurethane foam (PU). To study the effects of biopolyol on properties of PU foam, various ratios of biopolyol to commercial polyol were used. It was observed that the density and foaming time of the PU foam increases with the increase in biopolyol content. The calculated Isocyanate index showed that sugarcane bagasse polyol can be used to make flexible foam and that rice husk can be used to make rigid foam. Foaming times and full rise times increased with increase in the biopolyol content. The Fourier-transform infrared spectroscopy (FTIR) spectra of prepared foams showed the characteristic peaks related to PU foam. The morphological studies were carried out using scanning electron microscopy (SEM). Thermal conductivity tests proved that the synthesized PU foams can be used as insulating materials. Further, PU foams were also prepared with the incorporation of carbon nanotubes (CNTs) in the polyol. The densities, thermal conductivities and SEM analysis of PU foams with and without carbon nanotubes were compared.
Holistic Orphan Care: A Call for Change in Caring for Orphans and Vulnerable Children
Authors: Ladaphongphatthana Kanthamanee
Published: January 2021

Christians care for orphans and children without parental care in different forms. However, in the Global South, care is primarily provided in orphanages or large residential settings. Despite good intentions, there are limitations to provide a nurturing family environment for the children in such care environment. With current knowledge of alternative child care and in light of the holistic ministry, this article suggests an approach for the church to care for orphans and children at risk by focusing on the family and the local community. Additionally, simple steps to transition to holistic orphan care are offered.
When to Substitute a Missing Upper Lateral With a Canine: A Simplified Approach
Authors: Datta Renu
Published: January 2021

Introduction:

The upper lateral incisor is the most commonly missing tooth in the anterior segment. It leads to esthetic and functional imbalance for the patients. The ideal solution is the one that is most conservative and which fulfills the functional and esthetic needs of the concerned individual. Canine substitution is evolving to be the treatment of choice in most of the cases, because of its various advantages. These are special cases that need more time and effort from the clinicians due to space discrepancy in the upper and lower arches, along with the presentation of individual malocclusion.

Aims and Objectives:

Malocclusion occurring due to missing laterals is more complex, needing more time and effort from the clinicians because of space discrepancy, esthetic compromise, and individual presentation of the malocclusion. An attempt has been made in this article to review, evaluate, and tabulate the important factors for the convenience of clinicians.

Method:

All articles related to canine substitution were searched in the electronic database PubMed, and the important factors influencing the decision were reviewed. After careful evaluation, the checklist was evolved.

Result:

The malocclusions in which canine substitution is the treatment of choice are indicated in the tabular form for the convenience of clinicians. Specific treatment-planning considerations and biomechanics that can lead to an efficient and long-lasting result are also discussed.

Conclusion:

The need of the hour is an evidence-based approach, along with a well-designed prospective randomized control trial to understand the importance of each factor influencing these cases. Until that time, giving the available information in a simplified way can be a quality approach to these cases.
Professionalisation of short-term rentals and emergent tourism gentrification in post-crisis Thessaloniki
Authors: Katsinas Philipp
Published: January 2021

This paper contributes to research on short-term rentals (STRs), their suppliers and their impact on housing and the local community, focusing on Thessaloniki, a recessionary city off the tourist map until recently. Through the conduction of in-depth interviews with hosts and other key informants, and the analysis of quantitative data on Airbnb listings, I argue that: (1) far from enabling a sharing economy, Airbnb facilitates (re)investment in housing by different types of hosts. But investors outcompete amateur hosts and contribute to the professionalisation of STRs and the concentration of revenues. (2) the extraction of higher rents through STRs leads to the displacement of tenants and to gentrification in cities previously considered as ungentrifiable, driven by increased tourism and the short-term character of these rentals. However, the type and scale of investors involved, and the impact of gentrification are conditioned by contextual differences and the position of cities in the international competition to attract tourists.
Eastern Europe and the geography of knowledge production: The case of the invisible gardener
Authors: Jehlička Petr
Published: January 2021

The article contributes to the debates in geography on the inequality of knowledge production and the context-dependent hierarchy of knowledge claims. It seeks to make sense of the invisibility, to Western academia, of East European informal food provisioning as a research topic with the potential to inform debates and theorisations regarding alternative food systems. Looking at how East European informal food practices have been read from the West is instructive for understanding how certain knowledge ‘travels’ and becomes universally accepted knowledge – or theory – or remains a partial knowledge with validity restricted to specific places and circulating within specific subfields.
Impact of dust events on the optimization of photovoltaic-wind hybrid system in desert
Authors: Benallal Abdellah , Cheggaga Nawal
Published: January 2021

Reliable optimization of renewable energy systems has to be adapted to the installation site and its environmental factors. In dust event sources, the impact of dust on solar irradiance or on system’s production is not usually taken into consideration during optimization of photovoltaic (PV) or PV-wind hybrid systems. The first objective of this paper was to make observatory studies on wind velocity and lifting of Saharan dust that characterize Algerian desert which allowed us to extract a wind threshold for each event in our desert site. The second objective was to quantify this dust suspension and its negative impact, up to 47.46% on global solar irradiance (GSI) and 48.95% on photovoltaic yield effects were observed. The third and main objective of this paper was evaluating changes in optimized system when the dust impact was taken into account. To achieve that we adjusted GSI satellite data on HOMER software to dust presence, and then we run an optimization on HOMER with its GSI database and the new data, this data adjustment leads to a significant expansion of 13.70% on the size of PV generator, also 7.66% and 7.68% increase on the investment expenses and cost of energy respectively. Results obtained on this paper can be used to make PV-hybrid system’s technical and financial optimization in the main Algerian dust source trustworthy.
Effects of 12 Weeks of Progressive Early Active Exercise Therapy After Surgical Rotator Cuff Repair: 12 Weeks and 1-Year Results From the CUT-N-MOVE Randomized Controlled Trial
Authors: Kjær Birgitte Hougs , Magnusson S. Peter , Henriksen Marius , Warming Susan , Boyle Eleanor , Krogsgaard Michael Rindom , Al-Hamdani Ali , Juul-Kristensen Birgit
Published: January 2021

Background:

Traumatic full-thickness rotator cuff tears are typically managed surgically, followed by rehabilitation, but the load progression to reach an optimal clinical outcome during postoperative rehabilitation is unknown.

Purpose:

To evaluate whether there was a superior effect of 12 weeks of progressive active exercise therapy on shoulder function, pain, and quality of life compared with usual care.

Study Design:

Randomized controlled trial; Level of evidence, 1.

Methods:

Patients with surgically repaired traumatic full-thickness rotator cuff tears were recruited from 2 orthopaedic departments and randomized to progressive active exercise therapy (PR) or limited passive exercise therapy (UC [usual care]). The primary outcome was the change in the Western Ontario Rotator Cuff Index (WORC) score between groups from before surgery to 12 weeks after surgery. Secondary outcomes included changes in the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire score, pain, range of motion, and strength. Adverse events were registered during the intervention period.

Results:

A total of 82 patients were randomized to the PR (n = 41) or UC (n = 41) group. All 82 patients (100%) participated in the 12-week assessment and 79 in the 1-year follow-up. At 12 weeks, there was no significant difference between the groups in the change in the WORC score from baseline adjusted for age, sex, and center (physical symptoms: P = .834; sports and recreation: P = .723; work: P = .541; lifestyle: P = .508; emotions: P = .568). Additionally, there was no between-group difference for the secondary outcomes including the WORC score at 1 year and the DASH score, pain, range of motion, and strength at 12 weeks and 1 year. Both groups showed significant improvements over time in all outcomes. In total, there were 13 retears (16%) at 1-year follow-up: 6 in the PR group and 7 in the UC group.

Conclusion:

PR did not result in superior patient-reported and objective outcomes compared with UC at either short- or long-term follow-up (12 weeks and 1 year).

Registration:

NCT02969135 ( ClinicalTrials.gov identifier)
Extracellular vesicles from three dimensional culture of human placental mesenchymal stem cells ameliorated renal ischemia/reperfusion injury
Authors: Zhang Xuefeng , Wang Nan , Huang Yuhua , Li Yan , Li Gang , Lin Yuxin , Atala Anthony J. , Hou Jianquan , Zhao Weixin
Published: January 2021

Background:

Three-dimensional (3D) culture has been reported to increase the therapeutic potential of mesenchymal stem cells (MSCs). The present study assessed the therapeutic efficacy of extracellular vesicles (EVs) from 3D cultures of human placental MSCs (hPMSCs) for acute kidney injury (AKI).

Methods:

The supernatants from monolayer culture (2D) and 3D culture of hPMSCs were ultra-centrifuged for EVs isolation. C57BL/6 male mice were submitted to 45 min bilateral ischemia of kidney, followed by renal intra-capsular administration of EVs within a 72 h reperfusion period. Histological, immunohistochemical, and ELISA analyses of kidney samples were performed to evaluate cell death and inflammation. Kidney function was evaluated by measuring serum creatinine and urea nitrogen. The miRNA expression profiles of EVs from 2D and 3D culture of hPMSCs were evaluated using miRNA microarray analysis.

Results:

The 3D culture of hPMSCs formed spheroids with different diameters depending on the cell density seeded. The hPMSCs produced significantly more EVs in 3D culture than in 2D culture. More importantly, injection of EVs from 3D culture of hPMSCs into mouse kidney with ischemia-reperfusion (I/R)-AKI was more beneficial in protecting from progression of I/R than those from 2D culture. The EVs from 3D culture of hPMSCs were more efficient against apoptosis and inflammation than those from 2D culture, which resulted in a reduction in tissue damage and amelioration of renal function. MicroRNA profiling analysis revealed that a set of microRNAs were significantly changed in EVs from 3D culture of hPMSCs, especially miR-93-5p.

Conclusion:

The EVs from 3D culture of hPMSCs have therapeutic potential for I/R-AKI.
Exploring General Versus Academic English Proficiency as Predictors of Adolescent EFL Essay Writing
Authors: Jo Claire W.
Published: January 2021

Language learning is context-dependent and requires learners to employ different sets of language skills to fulfill various tasks. Yet standardized English as a foreign language assessments tend to conceptualize English proficiency as a unidimensional construct. In order to distinguish English proficiency as separate context-driven constructs, I adopted a register-based approach to investigate academic English proficiency (i.e., specific set of language skills that support academic literacy) and general English proficiency (i.e., wide range of language skills undifferentiated by context that are measured by traditional assessments) as separate predictors of overall essay quality. In the study, students completed a general English proficiency assessment and an academic language proficiency assessment, and essays were coded for academic writing features at the lexical, syntactic, and discourse levels. Beyond the contribution of academic writing features and general English proficiency, academic English proficiency emerged as a significant contributor to essay quality. Findings suggest that academic English proficiency scores more precisely identified a subset of academic language skills that is relevant to essay writing. The article concludes by discussing implications for strategic writing instruction that articulates the key expectations of academic writing used in and beyond school contexts.
Understanding the self-polymerization mechanism of dopamine by molecular simulation and applying dopamine surface modification to improve the interfacial adhesion of polyimide fibers with epoxy resin matrix
Authors: Hu Xiaojun , Ke Ying , Zhang Mengying , Niu Hongqing , Wu Dezhen , Zhao Lili
Published: January 2021

The object of this paper is to interpret the self-polymerization mechanism of dopamine by molecular simulation and use dopamine polymerization to modify the surface properties of polyimide fibers for improving its interfacial adhesion strength with the epoxy resin matrix. Theoretically, the molecular simulation results of calculated energy band gaps and infrared spectrum of the intermediate products generated in the dopamine self-polymerization process confirmed that the spontaneity of self-polymerization of dopamine and the occurrence of intramolecular cyclization and intermolecular polymerization in the self-polymerization process of dopamine. Moreover, the interaction between polyimide and poly(dopamine) was simulated, and the calculated results showed that the interaction between them depended on hydrogen bonding and was verified by ultrasound treatment. Experimentally, the effect of dopamine treatment concentration on the surface properties of polyimide fibers was investigated. Obviously, after a relatively high dopamine concentration treatment, the surface roughness and surface energy of polyimide fibers were largely improved and the number of active groups on polyimide fibers surface were increased, which were altogether conducive to enhance the adhesion strength of polyimide fibers with the epoxy resin matrix.
BP neural Network-Kalman filter fusion method for unmanned aerial vehicle target tracking
Authors: Liu Yongqi , Nie Liangcheng , Dong Rui , Chen Gang
Published: January 2021

The poor real-time performance and target occlusion occurred easily when the UAV was tracking the target. In this paper, a target tracking method based on the Back Propagation neural network fusion Kalman filter algorithm was developed to solve the position prediction problem of the UAV target tracking in real time. Firstly, the target tracking algorithm was used to acquire the center position coordinates of the target on the onboard computer, and then the coordinate difference matrix was constructed to train the BP neural network in real time. Secondly, when the target was occluded by the obstacles judged by the Bhattacharyya coefficient, the BP neural network fusion Kalman filter algorithm was used to accurately predict the center position coordinates of the occluded target. Then the flight speed of UAV was calculated by the deviation between the coordinates of the target and the image center. Finally, the velocity command was sent to the UAV by the onboard computer. The experimental results shown that the target position predicted by BP neural network fusion Kalman filter algorithm was more accurate and robust in predicting the center position coordinates of the target, and the UAV can track the moving target on the ground stably.
Female Labour Supply in Tamil Nadu: Some Questions
Authors: Sundari S.
Published: January 2021

In this article, an attempt is made to study the trends and patterns of female work participation in Tamil Nadu across districts and examine the effect of structural transformation in the economy on women’s employment in the decade 2001–2011. There is a wide variation in the female work participation rate in the state. It is higher in agro-based, poor and most backward districts and is low in urbanized and industrialized districts as well as in districts with higher levels of per capita income, female literacy and unemployment. The analysis here shows that structural changes in the economy have not resulted in any dramatic change in the quality and quantity of women’s employment. Further, the casual labour segment has been expanding in rural Tamil Nadu with reductions in self-employment.
A Johnny Amidst Jugnus
Authors: Zahid Adnan , Zaffar M. Adeel , Aurengzeb Hamza
Published: January 2021

The case recounts the story of Johnny and Jugnu, the fast-food restaurant’s initial journey. The story is then supplemented by details of the marketing mix (price, product, place and promotion). All decisions have been made, except for the pricing decision. The case hinges on this important decision. The four partners seem to disagree on pricing, and the case data helps students make this decision for the protagonists.
Book review: Dong Wang, Longmen’s Stone Buddhas and Cultural Heritage: When Antiquity Met Modernity in China
Authors: Ray Himanshu Prabha
Published: January 2021

Dong Wang, Longmen’s Stone Buddhas and Cultural Heritage: When Antiquity Met Modernity in China (Lanham/Boulder/New York/London: Rowman and Littlefield Publishers, 2020). pp. 314, HB $95; PB $35. ISBN 9781538141120 (epub).