bluuebunny/crossref_metadata_2025 huggingface dataset:
Augmented reality as a product presentation tool: focusing on the role of product information and presence in AR
Authors: Kim Terry Haekyung , Choo Ho Jung
Published: July 2021

As augmented reality (AR) technology advances, marketers are eager to adopt the technology for communication to persuade consumers to develop favorable attitudes and behaviors toward their products and services. This study aims to investigate the effect of product information (utilitarian vs. hedonic attributes) and presence on consumers’ product evaluation in AR. Through a quasi experiment, this study demonstrates how product attribute information and presence in AR affect product evaluation by mediating imagery, information fulfillment, and psychological ownership. At the same time, this study identifies the moderating role of consumers’ technological innovativeness in the effect of presence on consumers’ imagery. This research offers new insights into the role of product information in AR, which previous studies lack, to explore and highlight the predictors of positive product experiences in AR. Innovative marketers are likely to benefit from this study in developing product presentation tactics with AR technology.
Postgraduate radiology education: what has Covid-19 changed?
Authors: Nanapragasam Andrew , Mashar Meghavi
Published: July 2021

Radiology training in the UK follows a standardised pathway with formative and summative assessments throughout. The Covid-19 pandemic has affected multiple existing educational methods commonly used during radiology training including small group teaching, multidisciplinary team meetings, online e-learning modules, radiology courses, exam provision and more. As such, significant adaptations have been implemented in order to maintain the standard of radiology training which come with their respective advantages and disadvantages. However, the question still remains as to the effectiveness of these methods, their acceptability and longevity. In this review, we discuss these educational adaptations and future directions for training in the ongoing pandemic.
Monitoring enlarged dental follicles: case report and literature review of an unusual presentation of a unicystic ameloblastoma
Authors: Long Lily , Matharu Jasveen , Sah Sunil
Published: July 2021

An ameloblastoma is a benign, yet locally aggressive odontogenic tumour. The vast majority (80%) of ameloblastomas arise in the mandible, and unicystic ameloblastomas are commonly found in relation to an unerupted lower third molar. We present the case of a 39-year-old patient with an incidental finding of an enlarged dental follicle around an unerupted lower third molar that progressed to an extensive unicystic ameloblastoma. This ameloblastoma was decompressed and marsupialized before enucleation to reduce the risk of pathological fracture due to the extensive size of the tumour.

CPD/Clinical Relevance: The case is relevant to general dental practitioners when considering monitoring dental follicles of unerupted teeth because the enlarged dental follicle described progressed to an extensive odontogenic tumour.
Point-of-Care (POC) diagnostics for coronavirus disease 2019 (COVID-19) and their potential impact on dentistry
Authors: Samaranayake Lakshman , Kinariwala Niraj
Published: July 2021

It is clear that the coronavirus disease 2019 (COVID-19) pandemic, due to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) will be with us for the foreseeable future, possibly entrenched as an endemic infection. This poses a grave threat for clinical dental practice as asymptomatic (viral) carriers unknowing of their status, may attend for treatment with the possibility of resultant disease spread to non-immune individuals in the clinic. Even if one is immune through vaccination, the temporal waning of protective antibodies may lead to mild–moderate variant-induced infection, as shown in a number of recent studies. Hence, it is likely that rapid and accurate identification of COVID-19 patients at the point-of-care (POC), that is in the clinic or during the pre-attendance period, will be a critical imperative in the foreseeable future, as a secondary safeguard, in addition to successful vaccination. There are now an array of POC diagnostic tests to detect SARS-CoV-2, and here we summarize their salient features, and the potential utility as an infection control measure in dentistry.

CPD/Clinical Relevance: To describe the currently available POC diagnostic tests for COVID-19, and their utility as a critical infection control measure during dental care delivery in the immediate post-pandemic period.
A Study of Secondary School Students’ Perceptions of Fictional Characters
Authors: Sen Erhan , Karagul Sedat
Published: July 2021

Fictional characters give literary works a sense of reality. The actions of fictional characters play a crucial role in children's personality development. Young readers who lack critical reading skills are more likely to incorporate fictional characters into their lives because they have a hard time telling reality from fiction. Therefore, we should determine how children perceive fictional characters and teach them that they are imaginary figures. In this way, we can help them approach those characters' actions from an external and critical perspective. This study adopted a qualitative research design (case study) to investigate secondary school students' perceptions of fictional characters. The sample consisted of 45 secondary school students (28 female and 17 male). Data were collected through interviews and document review techniques. Data were analyzed using content analysis. Results showed that participants were more likely to be interested in and identify with characters with appealing personality traits. They had four types of approaches to fictional characters: (1) Wanting to change the storyline depending on what the fictional character goes through, (2) being influenced by them, (3) seeing them as role models, or (4) ignoring them. They wanted to change the storyline, especially when the villain got what he wanted or when the hero or the victim was unhappy, suggesting that they mostly took the protagonist's side (the good guy). While most participants attributed an ontological meaning to anthropomorphic characters, the symbolic meaning became of secondary importance. They were more interested in and identified more with characters with good living conditions and no death experiences.
On tensor GMRES and Golub-Kahan methods via the T-product for color image processing
Authors: El Guide Mohamed , El Ichi Alaa , Jbilou Khalide , Sadaka Rachid
Published: July 2021

The present paper is concerned with developing tensor iterative Krylov subspace methods to solve large multi-linear tensor equations. We use the T-product for two tensors to define tensor tubal global Arnoldi and tensor tubal global Golub-Kahan bidiagonalization algorithms. Furthermore, we illustrate how tensor-based global approaches can be exploited to solve ill-posed problems arising from recovering blurry multichannel (color) images and videos, using the so-called Tikhonov regularization technique, to provide computable approximate regularized solutions. We also review a generalized cross-validation and discrepancy principle type of criterion for the selection of the regularization parameter in the Tikhonov regularization. Applications to image sequence processing are given to demonstrate the efficiency of the algorithms.
Language skills in student essays: social disparities and later educational attainment
Authors: Weber Maximilian
Published: July 2021

This article examines the role of language skills in socially stratified educational attainment. Using essays written at the age of 11 in a large British cohort study, the National Child Development Study (NCDS), two measures of written language skills are derived: lexical diversity and the number of spelling and grammar errors. Results show that participants from the lower social strata misspelt more words and used a smaller variety of words in their essays than more socially privileged cohort members. Those language skills mediate part of the association between social origin and the highest level of educational attainment achieved. An even higher mediation of about half can be observed if standardised test measures for verbal and non-verbal cognitive abilities are included in the model. The models show that language skills mediate the social origin effect on educational attainment by about a quarter.
The ethical dilemmas of foodbanking: an analysis of the More Than Food programme
Authors: Parr Sadie , Hawkins Anna , Dayson Chris
Published: July 2021

This article contributes to debates about the ethicality of foodbanks, a pervasive element of the UK welfare support infrastructure. Drawing on qualitative interview data, we use the concepts of ‘food poverty knowledge’ and ‘lay morality’ to analyse the narratives of those running a major Trussell Trust ‘foodbank-plus’ programme and explore inherent moral sentiments therein about how those who are in food poverty are understood. We identify a contradiction between foodbankers’ ‘structural’ understanding of poverty and the implicitly agential assumptions that underpin the programme. We suggest that this represents a precarious ethical position on which to base practice.
Wearable light spectral sensor optimized for measuring daily α-opic light exposure
Authors: Mohamed Anas , Kalavally Vineetha , Cain Sean W. , Phillips Andrew J. K. , McGlashan Elise M. , Tan Chee Pin
Published: July 2021

Light has many non-visual effects on human physiology, including alterations in sleep, mood, and alertness. These effects are mainly mediated by photoreceptors containing the photopigment melanopsin, which has a peak sensitivity to short wavelength (‘blue’) light. Commercially available light sensors are commonly wrist-worn and report photopic illuminance and are calibrated to perceive visual brightness and hence cannot be used to investigate the non-visual impacts of light. In this paper, we report the development of a wearable spectrophotometer designed to be worn as a pendant or affixed to clothing to capture spectral power density data close to eye level in the visible wavelength range 380-780 nm. From this, the relative impact of a given light stimulus can be determined for each photoreceptive input in the human eye by calculating effective illuminances. This device showed high accuracy for all effective illuminances while measuring a range of commonly encountered light sources by calibrating for directional response, dark noise, sensor saturation, non-linearity, stray-light and spectral response. Features of the device include IoT-integration, onboard data storage and processing, Bluetooth Low Energy (BLE) enabled data transfer, and cloud storage in one cohesive unit.
Differential real-time single-pixel imaging with Fourier domain regularization: applications to VIS-IR imaging and polarization imaging
Authors: Pastuszczak Anna , Stojek Rafał , Wróbel Piotr , Kotyński Rafał
Published: July 2021

The speed and quality of single-pixel imaging (SPI) are fundamentally limited by image modulation frequency and by the levels of optical noise and compression noise. In an approach to come close to these limits, we introduce a SPI technique, which is inherently differential, and comprises a novel way of measuring the zeroth spatial frequency of images and makes use of varied thresholding of sampling patterns. With the proposed sampling, the entropy of the detection signal is increased in comparison to standard SPI protocols. Image reconstruction is obtained with a single matrix-vector product so the cost of the reconstruction method scales proportionally with the number of measured samples. A differential operator is included in the reconstruction and following the method is based on finding the generalized inversion of the modified measurement matrix with regularization in the Fourier domain. We demonstrate 256 × 256 SPI at up to 17 Hz at visible and near-infrared wavelength ranges using 2 polarization or spectral channels. A low bit-resolution data acquisition device with alternating-current-coupling can be used in the measurement indicating that the proposed method combines improved noise robustness with a differential removal of the direct current component of the signal.
Permutation entropy analysis of the output of a laser diode under stimulated Brillouin scattering optical feedback
Authors: Quintero-Rodríguez Leidy Johana , Zaldívar-Huerta Ignacio Enrique , Hong Yanhua , Masoller Cristina , Lee Min Won
Published: July 2021

The chaotic output emitted by a diode laser with optical feedback has fascinated the community for decades. The external cavity delay time imparts a weak level of periodicity to the laser output (the so-called "time delay signature", TDS) that is a drawback for applications that require random optical signals. A lot of efforts have focused in suppressing the TDS either by post-processing the signal or by using alternative ways to generate random optical signals. Here, we compare the signals generated by two optical feedback setups: in the first one, the stimulated Brillouin backscattered light from a standard optical fibre is re-injected into the laser (stimulated Brillouin scattering optical feedback, SBSOF); in the second one, the light transmitted through the fibre is re-injected into the laser (conventional optical feedback, COF). We analyse the permutation entropy, a well-known measure of complexity that captures order relations between values of a time series. We find that, on average, the signal generated by the SBSOF setup has slightly lower PE than the one generated by the COF setup, except when the sampling time of the intensity signal is an exact multiple of the delay; in that case, due to TDS, the entropy of the COF signal is lower than that of the SBSOF signal. We interpret the lower entropy value of the SBSOF signal as due to oscillations at the Brillouin frequency shift. Taken together, our results show that TDS suppression can have an undesirable side effect: a decrease of the entropy of the signal.
Longitudinal magnetization superoscillation enabled by high-order azimuthally polarized Laguerre-Gaussian vortex modes
Authors: Liu Xiaofei , Yan Weichao , Nie Zhongquan , Liang Yue , Wang Yuxiao , Jiang Zehui , Song Yinglin , Zhang Xueru
Published: July 2021

We present an all-optical scheme for the generation of longitudinal magnetization superoscillation based on the vectorial diffraction theory and the inverse Faraday effect. To achieve this, an azimuthally polarized high-order Laguerre–Gaussian vortex mode is firstly focused by a high numerical aperture (NA) objective and then impinges on an isotropic magneto-optical material. It is found that, by judiciously controlling the intrinsic arguments (radial mode index (p) and truncation parameter (β)) of such a configurable vectorial vortex beam, the longitudinal magnetic domain induced in the focal plane can be switched from a peak sub-wavelength magnetization (> 0.36λ/NA), via the fastest Fourier magnetization component (∼0.36λ/NA), to a super-oscillation magnetization hotspot (< 0.36λ/NA). We further examine the dependence of the transverse size, the side lobe, and the energy conversion efficiency within the focal magnetization domain on both the p and β of the initial vortex modes, confirming that the higher-order structured vortex beams are preferable alternatives to trigger robust longitudinal magnetization superoscillation. In addition, the underlying mechanisms behind the well-defined magnetization phenomena are unveiled. The ultra-small-scale longitudinal magnetization demonstrated here may hold massive potential applications in high-density all-optical magnetic recording/storage, super-resolution magnetic resonance imaging, atom trapping and spintronics.
Nontoxic Gd3+ and Tb3+ co-induced polyelectrolyte nano-aggregates (GTIPAs) for luminescence/magnetic resonance dual-modality imaging
Authors: Li Taisen , Liu Jin , Wang Xinzhi , Aleem Abdur Raheem , Wang Yao , Kipper Matt J. , Belfiore Laurence A. , Tang Jianguo
Published: July 2021

Multimodal nanoprobes are of great significance in clinical diagnosis, because they integrate the advantages of multiple imaging methods. The combination of multiple imaging modes provides more comprehensive and complex information than single-mode imaging, which can greatly improve clinical diagnoses. In this paper, Gd3+ and Tb3+ co-induced polyelectrolyte nanoaggregates (GTIPAs) are introduced as a novel dual-mode imaging probe. Containing gadolinium and terbium, GTIPAs are regular spherical nanoparticles, whose diameters are about 150 nm. As a fluorescent nanomaterial, GTIPAs have strong and stable luminescence intensity. At the same time, as an MRI contrast agent, GTIPAs exhibit a good contrast effect and a high longitudinal relaxation rate. In addition, the polyelectrolytes reduce the cytotoxicity of the complexes, confering excellent biocompatibility and water solubility. Therefore, GTIPAs are non-toxic luminescence/magnetic resonance dual-mode imaging probes.
Beyond the chemical master equation: Stochastic chemical kinetics coupled with auxiliary processes
Authors: Lunz Davin , Batt Gregory , Ruess Jakob , Bonnans J. Frédéric
Published: July 2021

The chemical master equation and its continuum approximations are indispensable tools in the modeling of chemical reaction networks. These are routinely used to capture complex nonlinear phenomena such as multimodality as well as transient events such as first-passage times, that accurately characterise a plethora of biological and chemical processes. However, some mechanisms, such as heterogeneous cellular growth or phenotypic selection at the population level, cannot be represented by the master equation and thus have been tackled separately. In this work, we propose a unifying framework that augments the chemical master equation to capture such auxiliary dynamics, and we develop and analyse a numerical solver that accurately simulates the system dynamics. We showcase these contributions by casting a diverse array of examples from the literature within this framework and applying the solver to both match and extend previous studies. Analytical calculations performed for each example validate our numerical results and benchmark the solver implementation.
A model of resource partitioning between foraging bees based on learning
Authors: Dubois Thibault , Pasquaretta Cristian , Barron Andrew B. , Gautrais Jacques , Lihoreau Mathieu
Published: July 2021

Central place foraging pollinators tend to develop multi-destination routes (traplines) to exploit patchily distributed plant resources. While the formation of traplines by individual pollinators has been studied in detail, how populations of foragers use resources in a common area is an open question, difficult to address experimentally. We explored conditions for the emergence of resource partitioning among traplining bees using agent-based models built from experimental data of bumblebees foraging on artificial flowers. In the models, bees learn to develop routes as a consequence of feedback loops that change their probabilities of moving between flowers. While a positive reinforcement of movements leading to rewarding flowers is sufficient for the emergence of resource partitioning when flowers are evenly distributed, the addition of a negative reinforcement of movements leading to unrewarding flowers is necessary when flowers are patchily distributed. In environments with more complex spatial structures, the negative experiences of individual bees on flowers favour spatial segregation and efficient collective foraging. Our study fills a major gap in modelling pollinator behaviour and constitutes a unique tool to guide future experimental programs.
Evaluating the impact of multivariate imputation by MICE in feature selection
Authors: Mera-Gaona Maritza , Neumann Ursula , Vargas-Canas Rubiel , López Diego M.
Published: July 2021

Handling missing values is a crucial step in preprocessing data in Machine Learning. Most available algorithms for analyzing datasets in the feature selection process and classification or estimation process analyze complete datasets. Consequently, in many cases, the strategy for dealing with missing values is to use only instances with full data or to replace missing values with a mean, mode, median, or a constant value. Usually, discarding missing samples or replacing missing values by means of fundamental techniques causes bias in subsequent analyzes on datasets.Aim: Demonstrate the positive impact of multivariate imputation in the feature selection process on datasets with missing values.Results: We compared the effects of the feature selection process using complete datasets, incomplete datasets with missingness rates between 5 and 50%, and imputed datasets by basic techniques and multivariate imputation. The feature selection algorithms used are well-known methods. The results showed that the datasets imputed by multivariate imputation obtained the best results in feature selection compared to datasets imputed by basic techniques or non-imputed incomplete datasets.Conclusions: Considering the results obtained in the evaluation, applying multivariate imputation by MICE reduces bias in the feature selection process.
Loss of mitochondrial transcription factor A in neural stem cells leads to immature brain development and triggers the activation of the integral stress response in vivo
Authors: Kuroda Rintaro , Tominaga Kaoru , Kasashima Katsumi , Kuroiwa Kenji , Sakashita Eiji , Hayakawa Hiroko , Kouki Tom , Ohno Nobuhiko , Kawai Kensuke , Endo Hitoshi
Published: July 2021

Mitochondrial dysfunction is significantly associated with neurological deficits and age-related neurological diseases. While mitochondria are dynamically regulated and properly maintained during neurogenesis, the manner in which mitochondrial activities are controlled and contribute to these processes is not fully understood. Mitochondrial transcription factor A (TFAM) contributes to mitochondrial function by maintaining mitochondrial DNA (mtDNA). To clarify how mitochondrial dysfunction affects neurogenesis, we induced mitochondrial dysfunction specifically in murine neural stem cells (NSCs) by inactivating Tfam. Tfam inactivation in NSCs resulted in mitochondrial dysfunction by reducing respiratory chain activities and causing a severe deficit in neural differentiation and maturation both in vivo and in vitro. Brain tissue from Tfam-deficient mice exhibited neuronal cell death primarily at layer V and microglia were activated prior to cell death. Cultured Tfam-deficient NSCs showed a reduction in reactive oxygen species produced by the mitochondria. Tfam inactivation during neurogenesis resulted in the accumulation of ATF4 and activation of target gene expression. Therefore, we propose that the integrated stress response (ISR) induced by mitochondrial dysfunction in neurogenesis is activated to protect the progression of neurodegenerative diseases.
Bacterial phagocytosis and reactive oxygen species production by camel neutrophils and monocytes are influenced by the type of anticoagulation agent
Authors: Al Humam Naser Abdallah
Published: July 2021

Background and Aim: Anticoagulants with different modes of action are used in the collection of camel blood samples. In the innate immune response, camel neutrophils and monocytes can play several roles during infection and inflammation. For anticoagulants ethylenediaminetetraacetic acid (EDTA) and heparin, research has described their effects on different parameters of the immune system. However, to date, no research has examined the effects of anticoagulants on the functional activity of camel phagocytes. Therefore, this study analyzed the influence of K3EDTA and lithium heparin on the antimicrobial activity of camel neutrophils and monocytes.

Materials and Methods: Camel leukocytes were separated from blood collected in EDTA or heparin tubes, and their phagocytosis and reactive oxygen species (ROS) production activity were analyzed by flow cytometry after stimulation with Staphylococcus aureus or Escherichia coli bacteria.

Results: In comparison to the cells collected from the EDTA blood, the camel neutrophils and monocytes separated from the heparin blood showed higher phagocytosis activity of S. aureus and E. coli. In addition, the neutrophils and monocytes produced significantly more ROS when the blood was collected in the heparin tubes.

Conclusion: The antimicrobial functions of camel neutrophils and monocytes are significantly affected by the type of anticoagulation agent. Therefore, using heparin rather than EDTA as an anticoagulant is recommended when performing the functional analysis of phagocytosis and ROS production of camel phagocytes.
Desain Paduan Logam Untuk Komponen Turbin Pembangkit Listrik
Authors:   Indonesian Institute Of Sciences, Efendi Efendi
Published: July 2021

Dalam pengembangan paduan logam untuk sudu turbin gas, penulis telah mendesain komposisi kimia dan struktur mikro paduan-super berbasis nikel kristal tunggal generasi baru berdasarkan interaksi unsur-unsur paduan pada suhu tinggi. Paduan-super generasi baru ini dicirikan oleh kandungan unsur refraktori yang tinggi untuk meningkatkan kekuatan creep dan kandungan unsur yang menekan presipitasi fasa yang merusak pada suhu tinggi. Interaksi unsur-unsur paduan pada suhu tinggi dievaluasi dengan menganalisis data interdifusi di dalam paduan nikel yang diperoleh secara eksperimen. Berkaitan dengan paduan logam untuk sudu turbin uap, penulis melakukan desain baja tahan karat martensitik dan baja tahan karat austenitik, baik dari sisi komposisi kimia maupun perlakuan panasnya. Desain menghasilkan baja tahan karat martensitik dengan komposisi modifikasi yang memiliki kekuatan mekanik, ketahanan abrasi, dan ketahanan korosi sumuran yang lebih baik dari baja tahan karat martensitik standar 410. Selain itu, dihasilkan juga komposisi baja tahan karat austenitik Fe-25Ni-15Cr modifikasi yang memiliki kekerasan dan ketahanan korosi sumuran yang lebih baik dari baja tahan karat austenitik Fe-25Ni-15Cr standar. Buku orasi ini menyajikan permasalahan yang terjadi pada turbin gas dan turbin uap, perkembangan dan desain paduan-super berbasis nikel untuk aplikasi sudu turbin gas, serta perkembangan dan desain baja tahan karat untuk aplikasi sudu turbin uap. Hilirisasi hasil desain paduan-paduan ini untuk turbin pembangkit listrik tenaga gas (PLTG) dan tenaga uap (PLTU) di Indonesia juga disajikan dalam buku orasi ini.
Research on the key technology of TIED-arch bridge Incremental Launching Method Construction
Authors: Zhang Kexin
Published: July 2021

Steel tied arch bridge has been widely used in modern bridge construction due to its beautiful shape, high material utilization rate and overall structural stiffness. However, there are few cases in which the tied-arch bridge is constructed by incremental launching . Based on the steel tied arch bridge project, this paper uses finite element software to establish the finite element simulation analysis of the construction process, and monitors the construction process of the bridge. The test results show that it is in the most unfavorable state when the cantilever at the end of the bridge reaches the maximum. At this time, the stress at the 117 m position of the beam reaches the maximum, the stress at the top edge is 33.7 MPa, and the stress at the bottom edge is -58.2 MPa. The stress in other sections did not exceed 30 MPa, and the beam was under uniform stress. When the foot of the internal arch passes through the temporary pier, the supporting force of the pier is maximum, which is about 6000 kN. The reasonable range of α is between 0.55 and 0.65, which is the ratio between the length Ln of launching nose and the maximum span L of incremental launching .
Residents' Assessment in Kaligawe Slum Area, Semarang
Authors: Jayanimitta Maria Ekacarini , Mardiansjah Fadjar Hari
Published: July 2021

To reduce slum areas, the government of Semarang City has issued a decree of determination of slum areas in 2014 and initiated some slum upgrading activities from the central and local government. Kaligawe, as one of the areas close to the industrial estate and has many residents, is included in a slum area that must be handled. The slum area in Kaligawe consists of 7.35 hectares from RW 1 – RW 4. In addition to the description of the slum characteristics, residents' assessment is also needed regarding the neighborhood condition. This study aims to analyze residents’ assessment in Kaligawe as one of the slum areas in Semarang. This study applied a questionnaire survey that was distributed to 90 residents of Kelurahan Kaligawe slum area randomly from RW 1 – RW 4 and NUAP Kaligawe 2017 document review as the data collection source. The findings indicated that although Kaligawe has a low socioeconomic level, the residents’ assessment of Kaligawe’s neighborhood is overall good. It is because they are already used to live with recent neighborhood conditions, and also significant improvement resulted due to slum upgrading program in Kaligawe area.
On Weak Super Ricci Flow through Neckpinch
Authors: Lakzian Sajjad , Munn Michael
Published: July 2021

In this article, we study the Ricci flow neckpinch in the context of metric measure spaces. We introduce the notion of a Ricci flow metric measure spacetime and of a weak (refined) super Ricci flow associated to convex cost functions (cost functions which are increasing convex functions of the distance function). Our definition of a weak super Ricci flow is based on the coupled contraction property for suitably defined diffusions on maximal diffusion subspaces. In our main theorem, we show that if a non-degenerate spherical neckpinch can be continued beyond the singular time by a smooth forward evolution then the corresponding Ricci flow metric measure spacetime through the singularity is a weak super Ricci flow for a (and therefore for all) convex cost functions if and only if the single point pinching phenomenon holds at singular times; i.e., if singularities form on a finite number of totally geodesic hypersurfaces of the form {x} × 𝕊
n
. We also show the spacetime is a refined weak super Ricci flow if and only if the flow is a smooth Ricci flow with possibly singular final time.
Hölder Parameterization of Iterated Function Systems and a Self-Affine Phenomenon
Authors: Badger Matthew , Vellis Vyron
Published: July 2021

We investigate the Hölder geometry of curves generated by iterated function systems (IFS) in a complete metric space. A theorem of Hata from 1985 asserts that every connected attractor of an IFS is locally connected and path-connected. We give a quantitative strengthening of Hata’s theorem. First we prove that every connected attractor of an IFS is (1/s)-Hölder path-connected, where s is the similarity dimension of the IFS. Then we show that every connected attractor of an IFS is parameterized by a (1/ α)-Hölder curve for all α > s. At the endpoint, α = s, a theorem of Remes from 1998 already established that connected self-similar sets in Euclidean space that satisfy the open set condition are parameterized by (1/s)-Hölder curves. In a secondary result, we show how to promote Remes’ theorem to self-similar sets in complete metric spaces, but in this setting require the attractor to have positive s-dimensional Hausdorff measure in lieu of the open set condition. To close the paper, we determine sharp Hölder exponents of parameterizations in the class of connected self-affine Bedford-McMullen carpets and build parameterizations of self-affine sponges. An interesting phenomenon emerges in the self-affine setting. While the optimal parameter s for a self-similar curve in ℝ
n
is always at most the ambient dimension n, the optimal parameter s for a self-affine curve in ℝ
n
may be strictly greater than n.
The prostate health index and the percentage of [-2]proPSA maintain their diagnostic performance when calculated with total and free PSA from different manufacturers
Authors: Garrido Manuel M. , Ribeiro Ruy , Pinheiro Luís C. , Holdenrieder Stefan , Guimarães João T.
Published: July 2021

Objectives

To evaluate the diagnostic performance of the prostate health index (PHI) and of the percentage of [-2]proPSA (%[-2]proPSA) calculated with total and free PSA from non-Beckman Coulter manufacturers (Roche and Abbott), and compare it with the fully Beckman Coulter [-2]proPSA derivatives.

Methods

In this study, 237 men (PSA: 2–10 μg/L) scheduled for prostate biopsy were enrolled. %[-2]proPSA and PHI were calculated with total and free PSA from three manufacturers. Beckman Coulter PSA and [-2]proPSA were performed on the Access 2 analyzer (Hybritech calibration). Roche PSA was performed on the cobas e411 and the Abbott PSA on the Architect i2000sr. Statistical analysis was performed, considering prostate cancer (PCa) as the outcome.

Results

Univariate analysis showed that all indices were predictors of cancer, irrespective of the manufacturer (p<0.001). The AUC was similar for all manufacturers, both for %[-2]proPSA (Beckman Coulter: 0.756; Roche: 0.770; Abbott: 0.756) and PHI (Beckman Coulter: 0.776; Roche: 0.785; Abbott: 0.778). When considering the cutoffs that allowed 90% sensitivity, [-2]proPSA derivatives calculated with Roche and Abbott PSA had similar specificities and predictive values when compared to Beckman Coulter. The percentage of missed cancers (8–9%) was the same between manufacturers. The percentage of spared biopsies was significantly higher with Roche’s PHI (21.0%) and Abbott’s PHI (20.6%) than with Beckman Coulter’s PHI (17.2%).

Conclusions

In the PSA range between 2 and 10 μg/L, [-2]proPSA derivatives maintain their diagnostic performance in PCa detection when calculated with PSA from Roche and Abbott. This can lead to a broader implementation of these indices in clinical laboratories worldwide.
Detecting departures from meta-ellipticity for multivariate stationary time series
Authors: Bücher Axel , Jaser Miriam , Min Aleksey
Published: July 2021

A test for detecting departures from meta-ellipticity for multivariate stationary time series is proposed. The large sample behavior of the test statistic is shown to depend in a complicated way on the underlying copula as well as on the serial dependence. Valid asymptotic critical values are obtained by a bootstrap device based on subsampling. The finite-sample performance of the test is investigated in a large-scale simulation study, and the theoretical results are illustrated by a case study involving financial log returns.
Comparison of the effect of Ceratonia siliqua L. fruit oral capsule and vitamin E on semen parameters in men with idiopathic infertility: a triple-blind randomized controlled clinical trial
Authors: Sanagoo Sima , Farshbaf-Khalili Azizeh , Asgharian Parina , Hazhir Samad , Oskouei Behnaz Sadeghzadeh
Published: July 2021

Objectives

To compare the effect of oral Ceratonia siliqua (Carob) and vitamin E on sperm parameters in idiopathic infertile men.

Methods

In this triple-blind randomized controlled trial study, fifty 20–45-year-old infertile men with idiopathic abnormal sperm parameters were selected among men referring to the infertility clinic of Al Zahra-Iran Hospital, and randomly allocated into two groups. The first group received Carob capsules, 500 mg, and the second group received vitamin E capsules three times a day for 90 days. The primary outcomes of this study were the sperm parameters (count, motility, and morphology).

Results

After the intervention, the mean of sperm count increased from 49.08 to 60.22 million/mL in the carob vs. it increased from 47.64 to 58.88 million/mL in the vitamin E group (adjusted mean difference (aMD)=1.124 million/ml, 95% CI: −12.892 to 15.141). The mean sperm motility increased from 45.90 to 52.90% in the carob group but decreased from 55.23 to 38.10% in the vitamin E group (aMD=17.22%, 95% CI: 8.53 to 25.92). The mean sperms with normal morphology increased from 11.52 to 67.05% in the carob, and from 10.20 to 77.47% in the vitamin E group (aMD=−10.88%, 95% CI: −22.30 to 0.536). There was no serious side effect during the treatment course.

Conclusions

Taking 1,500 mg oral dose of Carob capsule per day for 90 days improved sperm motility but had no significant effect for improving morphology and count comparing to vitamin E capsule.
Toward agent-based LSB image steganography system
Authors: Baothman Fatmah Abdulrahman , Edhah Budoor Salem
Published: July 2021

In a digital communication environment, information security is mandatory. Three essential parameters used in the design process of a steganography algorithm are Payload, security, and fidelity. However, several methods are implemented in information hiding, such as Least Significant Bit (LBS), Discrete Wavelet Transform, Masking, and Discrete Cosine Transform. The paper aims to investigate novel steganography techniques based on agent technology. It proposes a Framework of Steganography based on agent for secret communication using LSB. The most common image steganography databases are explored for training and testing. The methodology in this work is based on the statistical properties of the developed agent software using Matlab. The experiment design is based on six statistical feature measures, including Histogram, Mean, Standard deviation, Entropy, Variance and Energy. For steganography, an Ensemble classifier is used to test two scenarios: embedding a single language message and inserting bilingual messages. ROC Curve represents the evaluation metrics. The result shows that the designed agent-based system with 50% training/testing sample set and 0.2 Payload can pick out the best cover image for the provided hidden message size to avoid visual artifact.
Kinship terminologies reveal ancient contact zone in the Hindu Kush
Authors: Liljegren Henrik
Published: July 2021

The Hindu Kush, or the mountain region of northern Pakistan, north-eastern Afghanistan and the northern-most part of the Indian-administered Kashmir region, is home to approximately 50 languages belonging to six different genera: Indo-Aryan, Iranian, Nuristani, Sino-Tibetan, Turkic and the isolate Burushaski. Areality research on this region is only in its early stages, and while its significance as a convergence area has been suggested by several scholars, only a few, primarily phonological and grammatical, features have been studied in a more systematic fashion. Cross-linguistic research in the realms of semantics and lexical organization has been given considerably less attention. However, preliminary findings indicate that features are geographically bundled with one another, across genera, in significant ways, displaying semantic areality on multiple levels throughout the region or in one or more of its sub-regions. The present study is an areal-typological investigation of kinship terms in the region, in which particular attention is paid to a few notable polysemy patterns and what appears to be a significant geographical clustering of these. Comparisons are made between the geographical distribution of such patterns and those of some other linguistic features as well as with relevant non-linguistic factors related to shared cultural values or identities and a long history of small-scale cross-community interaction in different parts of the region.
Asymptotic stability of the time-changed stochastic delay differential equations with Markovian switching
Authors: Zhang Xiaozhi , Zhu Zhangsheng , Yuan Chenggui
Published: July 2021

The aim of this work is to study the asymptotic stability of the time-changed stochastic delay differential equations (SDDEs) with Markovian switching. Some sufficient conditions for the asymptotic stability of solutions to the time-changed SDDEs are presented. In contrast to the asymptotic stability in existing articles, we present the new results on the stability of solutions to time-changed SDDEs, which is driven by time-changed Brownian motion. Finally, an example is given to demonstrate the effectiveness of the main results.
The price of immersion: language learners as a cheap workforce in Malta’s voluntourism industry
Authors: Schedel Larissa Semiramis
Published: July 2021

This contribution treats “language immersion” as a linguistic ideology and explores narratives, practices, and subjectivities pertinent to that notion in the context of language-motivated voluntourism. Voluntourism programs offer short-term sojourns abroad, which combine voluntary work with holidays while promising “immersion” as an efficient alternative to classroom language learning. In the Mediterranean island state of Malta, whose population is mostly bilingual in English and Maltese, voluntourism has become an attractive product for the booming English language travel industry. Since there is a lack of critical sociolinguistic and second language acquisition research on the language learning trajectories of voluntourists, this piece examines the promise of immersion through the example of a hostel that figures as a workplace. Drawing on ethnographic data, it investigates how learning English through immersion while working abroad is imagined and promoted, whether or not it occurs, and what gains (linguistic or otherwise) it generates and for whom. The article argues that the voluntourism industry appropriates the discourse of immersion to responsibilize English learners for their linguistic self-skilling, thereby constituting them as neoliberal subjects that can easily be exploited as a cheap workforce.
Manuscript Illumination in 19th-century Italy. Material Analysis of Two Partial Copies from the Squarcialupi Codex
Authors: Bosch Sebastian , Janke Andreas
Published: July 2021

The illuminations in two Italian manuscripts are still a mystery today. Both manuscripts were based fully or partly on the Florentine Squarcialupi Codex (Florence, Biblioteca Medicea Laurenziana, Med. Pal. 87) dating from around 1410/15. With the help of a multi-analytical, non-destructive approach employing mobile instrumentation (XRF spectroscopy, visible reflectance spectroscopy and infrared reflectography), we examined the manuscripts Toronto, Thomas Fisher Rare Book Library, MSS 09700 and Düsseldorf, Kunstpalast, Inv. K 1925-67 for the first time with regard to their production processes. The identification of modern pigments allows them to be contextualized in illumination practices of the 19th century. Manuals of that time provide a wealth of information on specific illumination practices and the availability of writing and painting materials, which correlates with the actual artefacts.
Active vibration suppression of wind turbine blades integrated with piezoelectric sensors
Authors: Lee Sang-Lae
Published: July 2021

As the wind turbine size gets larger, the optimal design of blades, which is a major source of energy for the wind turbines and also the cause of loads, is becoming more important than anything else. Therefore, reducing the load on the blade should be the top priority in designing a blade. In this article, we studied the vibration control of the stiffened wind blades subjected to a wind load with piezoelectric sensors and actuators to mitigate fluctuations in loading and adding damping to the blade. The model is a laminated composite blade with a shear web and the PZT piezomaterial layers embedded on the top and bottom surfaces act as a sensor and actuator, respectively. A uniformly distributed external wind load is assumed over the entire plate surface for simplicity. The first-order shear deformation (FSDT) theory is adopted, and Hamilton’s principle is used to derive the finite element equation of motion. The modal superposition technique and the Newmark-

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method are used in numerical analysis to calculate the dynamic response. Using the constant gain negative velocity feedback control algorithm, vibration characteristics and transient responses are compared. Furthermore, vibration control at various locations of the shear webs subjected to an external load is discussed in detail. Through various calculation results performed in this study, this article proposes a method of designing a blade that can reduce the load by actively responding to the external load acting on the wind turbine blade.
On interpolative Hardy-Rogers contractive of Suzuki type mappings
Authors: Yeşilkaya Seher Sultan
Published: July 2021

In this paper, we obtain a fixed point theoremω-ψ-interpolative Hardy-Rogers contractive of Suzuki type mappings. In the following, we present an example to illustrate the new theorem is applicable. Subsequently, some results are given. These results generalize several new results present in the literature.
Antibacterial activity of some chemical constituents from Trichilia prieuriana (Meliaceae)
Authors: Pagna Julio Issah Mawouma , Mbekou Ines Michèle Kanko , Tsamo Armelle Tontsa , Mkounga Pierre , Frese Marcel , Stammler Hans-Georg , Fekam Fabrice Boyom , Lenta Bruno Ndjakou , Sewald Norbert , Nkengfack Augustin Ephrem
Published: July 2021

The chemical study of hydroethanolic extracts from different parts of Trichilia prieuriana (Meliaceae) led to the isolation and identification of 22 compounds: 2β,3β,4β-trihydroxypregnan-16-one (1), prieurianin (2), flindissone (3), deoxyflindissone (4), picraquassin E (5), ursolic acid (6), 3β-acetoxy-11α-hydroxyurs-12-en (7), 3β-acetoxy-urs-12-en-11-one (8), 3β-acetoxy-β-amyrin (9), friedelin-3-ol (10), 3-oxo, friedelin (11), 3-oxo, fridelin-28-ol (12), oleanolic acid (13), hederagenin (14), mixture of stigmasterol (15), β-sitosterol (16), β-sitosterol-3-O-β-glucopyranoside (17) and stigmasterol-3-O-β-glucopyranoside (18), erythrodiol (19), scopoletin (20), 4-hydroxy-3,5-dimethoxybenzoic acid (21) and shikimic acid (22). The absolute configurations and crystal structures of compounds 1 and 2 are reported herein for the first time. Crude extracts, fractions and isolated compounds were evaluated for their antibacterial activities against nine bacterial strains. Crude extracts from the root wood of T. prieuriana exhibited good antibacterial potency with minimal inhibitory concentration (MIC) values ranging from 31.25 to 500 µg mL−1 on the test bacteria. The ethyl acetate fraction from root wood and n-hexane-ethyl acetate (3:1) fraction from leaves showed a moderate antibacterial activity with MIC value of 250 μg mL−1 on all test bacteria. Isolated compounds exhibited significant antibacterial activity with MIC values ranging from 4.09 to 71.8 µm. Compounds 3, 6 and 7 were the most active with a broad spectrum of activities.
Preparation and characterization of vitamin D microemulsions using two-component surface-active stabilizer system
Authors: Nourzadeh Zahra , Anarjan Navideh , Ebrahimzadeh Rajaei Gholamreza , Jafarizadeh-Malmiri Hoda
Published: July 2021

Vitamin D, like other functional lipid bioactive compounds, t suffers from less structural stability, poor water solubility and consequently less bioavailability and cellular uptake. Preparation of vitamin D microemulsions is one of the solutions for the above problems. Thus, in the present study, vitamin D microemulsions were prepared using various one/two-component stabilizer systems, namely, Tween 20 and sodium caseinate in various proportions. The effects of stabilizer components proportions on characteristics of gained vitamin D microemulsions were evaluated using a two-component mixture design of experiment. Therefore, various polynomial models were proposed in order to predict the characteristics of produced microemulsions. According to the optimization analysis, the vitamin D microemulsions stabilized by a stabilizer system composed of 70% Tween 20 and 30% sodium caseinate could produce the most desirable microemulsions with minimum mean particle size, polydispersity, and maximum zeta potential, transparency and vitamin D content. The produced vitamin D microemulsions showed acceptable chemical and good physical stabilities, which can be incorporated easily in water-based food and pharmaceutical formulations.