bluuebunny/crossref_metadata_2025 huggingface dataset:
The application of local rotating flap and latissimus dorsi flap in thoracic deformity correction
Authors: Zhang Xinling , Yang Xin , Wang Guanhuier , Chen Yujie , Zhao Zhenmin , Bi Hongsen , Chen Jing
Published: October 2021

Background

Wound healing problem is one of the main complications after correction of chest wall deformity. Orthopedic flap tissue repair technique has a clear significance in non‐healing wound and defect wound and provides a new choice for poor wound healing after orthopedic surgery of chest wall deformity.

Objective

To investigate, the application value of modified local rotary flap and latissimus dorsi myocutcutaneous flap in the treatment of poor wound healing after orthodontic treatment of chest wall deformity.

Method

A retrospective analysis was performed on patients who admitted to our department from August 2012 to November 2019 due to non‐healing incision after surgery for thoracic deformity. Skin flap was selected according to the size of the wound surface, and the effect of skin flap repair was observed. The clinical data of the included patients were recorded, and the preoperative and postoperative wound conditions were evaluated.

Results

This study included 13 patients with chest wall deformity who received plastic surgery tissue using flap technique for wound repair, 11 cases used modified local rotation skin flap, and 2 cases used modified latissimus dorsi myocutaneous flap. The mean age of the 13 patients was 18.54 ± 4.14 years old, the mean body mass index (BMI) was 17.02 ± 2.16 kg/m2, and the mean preoperative nonunion time of the incision was 64.77 ± 93.01 days. Five patients had positive bacteria culture on the wound surface, including 3 cases of Staphylococcus aureus, 1 case of Pseudomonas aeruginosa, and 1 case of Staphylococcus epidermidis. All the 13 patients achieved primary grade A healing.

Conclusion

The modified local rotary flap and latissimus dorsi musculocutaneous flap have a significant effect on the postoperative correction of chest wall deformity, which can ensure wound healing while retaining the orthopedic plate to the maximum extent to ensure the effect of the correction.
Ten‐year clinical performance of zirconia posterior fixed partial dentures
Authors: Matta Ragai‐Edward , Eitner Stephan , Stelzer Simon Paul , Reich Sven , Wichmann Manfred , Berger Lara
Published: October 2021

Background

With the constantly increasing demand for metal‐free solutions in dental therapy, numerous ceramic restorations have found their way into everyday clinical practice, but long‐term clinical data are limited.

Objective

The aim of this prospective clinical study was to evaluate three‐ and four‐unit fixed partial dentures in the posterior region made of zirconium dioxide frameworks veneered with feldspathic porcelain after 10 years in clinical use.

Methods

Based on the two studies published in 2009 and 2012, in which the all‐ceramic FDPs were evaluated after 3 and 5 years of function, a clinical evaluation of a total of 17 restorations after 10 years with regard to their condition and long‐term stability was carried out in the course of this study. The restorations were fabricated using feldspathic ceramic‐veneered, yttria‐stabilised, tetragonal zirconium dioxide as the framework material. The data collection was based on modified CDA criteria and included, for example, the shape, shade, surface condition and the success and survival rates of the restorations.

Results

The all‐ceramic prostheses embodied excellent biocompatibility and colour reproduction. As a result of an increased incidence of chipping fractures, the success rate was 60%. The survival rate, however, was 88.2%, as 2 of the 17 restorations were lost.

Conclusion

All‐ceramic concepts for FDP constructions in the posterior region achieved satisfactory results in terms of durability after 10 years. The main problem was chipping, as has been generally recognised. Nevertheless, the materials were characterised by excellent aesthetics and biocompatibility, which ultimately makes them a good alternative to conventional restorative options.

Trial registration

This study is registered in DRKS—German Clinical Trials Register with the register number DRKS00021743.
Antibacterial, antibiofilm and anti-quorum sensing activities of Muntingia calabura L. leaf extract against Pseudomonas aeruginosa
Authors: MosaChristas K. , Kowsalya E. , Karthick R. , Jaquline C.R.I.
Published: November 2021

The aim of this study was to evaluate the phytochemicals, antioxidant, antibacterial and anti-quorum sensing (QS) properties of methanol extract of Muntingia calabura L. leaves against biofilm-forming strain Pseudomonas aeruginosa. The antioxidant potential of M. calabura methanol leaf extract was evaluated using a radical scavenging assay. Since the findings were so promising, the study aims to screen the phytochemical profiles using qualitative and quantitative approaches and to expand the investigation to anti-QS activity. The antibacterial activity was assessed by determining the minimum inhibitory concentration against pathogenic Gram-negative and Gram-positive biofilm-forming bacterial strains using an agar well diffusion plate method. Muntingia calabura methanol leaf extract was most potent against P. aeruginosa. The QS controlled virulence factors in P. aeruginosa is significantly inhibited by M. calabura leaf extract. The microscopy images revealed a major reduction in P. aeruginosa biofilm formation. Interestingly, M. calabura leaf extract was not toxic to Vero cell line. These findings make M. calabura a strong candidate for new antimicrobial and anti-QS herbal agents.
Hypoxia as a physiological cue and pathological stress for coral larvae
Authors: Alderdice Rachel , Pernice Mathieu , Cárdenas Anny , Hughes David J. , Harrison Peter L. , Boulotte Nadine , Chartrand Katie , Kühl Michael , Suggett David J. , Voolstra Christian R.
Published: October 2021

Ocean deoxygenation events are intensifying worldwide and can rapidly drive adult corals into a state of metabolic crisis and bleaching‐induced mortality, but whether coral larvae are subject to similar stress remains untested. We experimentally exposed apo‐symbiotic coral larvae of Acropora selago to deoxygenation stress with subsequent reoxygenation aligned to their night‐day light cycle, and followed their gene expression using RNA‐Seq. After 12 h of deoxygenation stress (~2 mg O2/L), coral planulae demonstrated a low expression of HIF‐targeted hypoxia response genes concomitant with a significantly high expression of PHD2 (a promoter of HIFα proteasomal degradation), similar to corresponding adult corals. Despite exhibiting a consistent swimming phenotype compared to control samples, the differential gene expression observed in planulae exposed to deoxygenation‐reoxygenation suggests a disruption of pathways involved in developmental regulation, mitochondrial activity, lipid metabolism, and O2‐sensitive epigenetic regulators. Importantly, we found that treated larvae exhibited a disruption in the expression of conserved HIF‐targeted developmental regulators, for example, Homeobox (HOX) genes, corroborating how changes in external oxygen levels can affect animal development. We discuss how the observed deoxygenation responses may be indicative of a possible acclimation response or alternatively may imply negative latent impacts for coral larval fitness.
Not out of the woods yet: Signatures of the prolonged negative genetic consequences of a population bottleneck in a rapidly re‐expanding wader, the black‐faced spoonbill Platalea minor
Authors: Li Shou‐Hsien , Liu Yang , Yeh Chia‐Fen , Fu Yuchen , Yeung Carol K. L. , Lee Chun‐Cheng , Chiu Chi‐Cheng , Kuo Tung Hui , Chan Fang‐Tse , Chen Yu‐Chia , Ko Wen‐Ya , Yao Cheng‐Te
Published: November 2021

The long‐term persistence of a population which has suffered a bottleneck partly depends on how historical demographic dynamics impacted its genetic diversity and the accumulation of deleterious mutations. Here we provide genomic evidence for the genetic effect of a recent population bottleneck in the endangered black‐faced spoonbill (Platalea minor) after its rapid population recovery. Our data suggest that the bird's effective population size, Ne, had been relatively stable (7500–9000) since 22,000 years ago; however, a recent brief yet severe bottleneck (Ne = 20) which we here estimated to occur around the 1940s wiped out >99% of its historical Ne in roughly three generations. Despite a >15‐fold population recovery since 1988, we found that black‐faced spoonbill population has higher levels of inbreeding (7.4 times more runs of homozygosity) than its sister species, the royal spoonbill (P. regia), which is not thought to have undergone a marked population contraction. Although the two spoonbills have similar levels of genome‐wide genetic diversity, our results suggest that selection on more genes was relaxed in the black‐faced spoonbill; moreover individual black‐faced spoonbills carry more putatively deleterious mutations (Grantham's score > 50), and may therefore express more deleterious phenotypic effects than royal spoonbills. Here we demonstrate the value of using genomic indices to monitor levels of genetic erosion, inbreeding and mutation load in species with conservation concerns. To mitigate the prolonged negative genetic effect of a population bottleneck, we recommend that all possible measures should be employed to maintain population growth of a threatened species.
A retrospective study on patients with chronic knee pain treated with ultrasound‐guided radiofrequency of the genicular nerves (RECORGEN trial)
Authors: Belba Amy , Vanneste Thibaut , Van Kuijk Sander M. J. , Mesotten Dieter , Mestrum Roel , Van Boxem Koen , Van Lantschoot Astrid , Bellemans Johan , Van de Velde Marc , Van Zundert Jan
Published: October 2021

Introduction

Radiofrequency (RF) treatment of the genicular nerves is a promising treatment for chronic osteoarthritic and persistent postsurgical knee pain (PPSP), refractory to conventional medical management.

Methods

The RECORGEN study is a retrospective single‐center cohort study of patients treated with ultrasound‐guided conventional RF of the genicular nerves for chronic knee pain in Hospital Oost‐Limburg, Genk from September 2017 to June 2020. Subgroup analysis based on etiology of pain (PPSP and degenerative knee pain) was performed in addition to the total study population analysis. Outcome parameters were global perceived effect (GPE), Numeric Rating Scale for pain, consumption of strong opioids, and safety of the treatment at 6 weeks and cross‐sectionally at a variable time point. Treatment success was defined as GPE≥50%.

Results

Sixty‐eight cases were screened of which 59 (46 diagnosed with PPSP and 13 with degenerative knee pain) were included in the study. Treatment success at 6 weeks was achieved in 19 of 59 interventions (32.2%) and was similar in both groups. Seventeen responders were evaluated at follow‐up. 45.1% (8/17) continued to have a positive effect at the second time point. The mean duration of effect of the RF treatment was 8.3 months. Safety analysis at 6 weeks and at the second time point showed a good safety profile of the treatment.

Conclusion

Conventional RF of the genicular nerves was clinically successful in more than 30% of the study population refractory to conventional medical management. Overall, the treatment was well tolerated. The mean duration of effect was 8.3 months.
Exogenous melatonin mitigates salinity‐induced damage in olive seedlings by modulating ion homeostasis, antioxidant defense, and phytohormone balance
Authors: Zahedi Seyed Morteza , Hosseini Marjan Sadat , Fahadi Hoveizeh Narjes , Gholami Rahmatollah , Abdelrahman Mostafa , Tran Lam‐Son Phan
Published: October 2021

Melatonin (MEL) is a ubiquitous molecule with pleiotropic roles in plant adaption to stress. In this study, we investigated the effects of foliar spray of 100 and 200 μM MEL on the biochemical and physiological traits linked with the growth performance of olive seedlings exposed to moderate (45 mM NaCl) and severe (90 mM NaCl) salinity. Both salt stress conditions caused a considerable reduction in leaf relative water content and the contents of photosynthetic pigments (carotenoids, chlorophylls a and b, and total chlorophylls), K+ and Ca+2, while the contents of Na+ and the activities of antioxidant enzymes increased. In addition, salt‐stressed olive seedlings showed high accumulations of hydrogen peroxide (H2O2), malondialdehyde (MDA), and electrolyte leakage (EL), indicating that olive seedlings suffered from salinity‐induced oxidative damage. In contrast, MEL application revived the growth of olive seedlings, including shoot height, root length and biomass under salt stress conditions. MEL protected the photosynthetic pigments and decreased the Na+/K+ ratio under both moderate and severe salt stresses. Furthermore, MEL induced the accumulations of proline, total soluble sugars, glycine betaine, abscisic acid, and indole acetic acid in salt‐stressed olive seedlings, which showed a positive correlation with improved leaf water status and biomass. MEL application also increased the activities of catalase, superoxide dismutase, ascorbate peroxidase, and peroxidase in salt‐stressed seedlings, resulting in lower levels of H2O2, MDA, and EL in these plants. Taken together, MEL mitigates salinity through its roles in various biochemical and physiological processes, thereby representing a promising agent for application in crop protection.
Emotional distress among older adults during the COVID‐19 outbreak: understanding the longitudinal psychological impact of the COVID‐19 pandemic
Authors: López Javier , Perez‐Rojo Gema , Noriega Cristina , Martinez‐Huertas Jose Angel , Velasco Cristina
Published: October 2021

Background

Older adults have proven their ability to overcome adversities throughout their life. This study aims to assess the impact of the COVID‐19 pandemic on older adultsʼ psychological distress (anxiety and depression) over time.

Methods

A community‐dwelling Spaniard population (N = 192) completed a survey and reported on their sociodemographic characteristics, appraisal and personal resources. Older adults took part in a longitudinal online survey collected in April 2020 (during the lockdown restrictions) and at two subsequent time points 3 and 9 months after baseline (without lockdown restrictions and during the third wave of the pandemic respectively).

Results

Older adults did not evidence higher emotional distress than during the initial lockdown. Furthermore, depression remained stable and anxiety significantly decreased. Results also suggest that some sociodemographic characteristics, appraisals and personal resources are relevant. Older participants showed less anxiety than younger ones. Furthermore, being a male, resilience, and acceptance were related with the decrease of anxiety. Otherwise, fear of the COVID‐19 outbreak and depression were related with the increase of anxiety.

Conclusion

Older adults may adapt to the adverse pandemic impact by using more adaptive resources that reduce their distress. Efforts to ameliorate older adults' anxiety by focusing on older adults' personal resources should be considered.
Severe oral ulcerative and lichenoid lesions associated with adrenal insufficiency in a patient treated with nivolumab: Report of a case and review of literature
Authors: Gobbi Marcella Ferreira , Eduardo Fernanda de Paula , Bezinelli Leticia Mello , de Carvalho Danielle Lima Correa , Monção do Vale Silvana Kelly , Corrêa Luciana
Published: October 2021

Nivolumab, an antibody against anti‐programmed death type 1, has been used for treatment of advanced non‐small cell lung cancer with improvement of overall survival. Usually, diarrhea, cutaneous rash, and pruritus are reported as the most common immune‐related adverse effects of nivolumab therapy. Oral lesions and secondary adrenal insufficiency sometimes occur but usually are rare events. We report a case of a patient treated with nivolumab who then showed persistent oral ulcerative and lichenoid lesions, which were refractory to topical corticosteroids. The oral lesions were concomitant to nivolumab‐induced adrenal insufficiency. These adverse events led to nivolumab discontinuation, which favored oral lesion healing and adrenal insufficiency remission. Through a brief review of the literature concerning nivolumab toxicity in the oral cavity, we discuss the clinical aspect and management of these lesions.
Constructing the Racial Hierarchy of Labor: The Role of Race in Occupational Prestige Judgments*
Authors: Valentino Lauren
Published: October 2021

Sociologists of culture are interested in processes of valuation, such as the way we value the division of labor. Typically measured through occupational prestige, prior research on this topic has largely neglected the potential role of race in the construction of the status hierarchy. This study asks whether and how race shapes judgments of occupational prestige, drawing on key insights from the sociology of race and ethnicity (Whiteness as a credential, strategic assimilation) to test key predictions about racial composition and a person’s own racial identity in this process. Combining data from the 2012 General Social Survey with federal administrative data, I find that Whiter jobs are, in fact, seen as more prestigious, even after taking into account an occupation’s level of required education/training, pay, industry, and gender composition. Further analyses demonstrate that this pattern is primarily driven by White and Asian raters and by raters with a college degree. Overall, then, this study indicates that the racial segregation of occupations impacts not only wages but also the status they confer to their incumbents.
Classroom Assessment Data Use Practices Among Basic School Teachers in Ghana
Authors: Asamoah-Gyimah Kenneth
Published: October 2021

Assessment results can be a guide to instruction, and they can ensure that the prescribed curriculum is well covered. When assessment data are used as a means of making appropriate instructional adjustments for improvement, teaching and learning progresses. The study examined basic school teachers’ perception and use of assessment data. Cross-sectional survey design was used for the conduct of the study. Hundred and fifty (150) teachers within the Central region of Ghana were sampled from twenty (20) basic schools using systematic sampling procedure. A two-dimensional questionnaire was adapted, validated and used for the collection of research data. The data to provide answers to the study question were analysed using descriptive statistics, specifically, percentages and frequencies. The hypothesis was tested using Partial Least Square structural equation modelling approach. Findings revealed that in practice, basic school teachers use assessment data to plan instruction, evaluate students’ learning progress, determine curriculum strands to emphasize during teaching sessions and also to evaluate instructional effectiveness for the academic year. The study further showed that teacher perception about assessment significantly predict assessment data use. The study recommends that, tertiary institutions that train teachers must continue to place much emphasis on the teaching of ‘assessment in schools’ to deepen prospective teachers’ knowledge and utilization of assessment data for sustenance of positive ‘assessment data use practices’ in Ghana basic schools.
In situ ellipsometry aided rapid ALD process development and parameter space visualization of cerium oxide nanofilms
Authors: Kumar Udit , Feit Corbin , Berriel S. Novia , Arunachalam Ayush , Sakthivel Tamil Selvan , Basu Kanad , Banerjee Parag , Seal Sudipta
Published: November 2021

Process development in atomic layer deposition (ALD) is often time-consuming, requiring optimization of saturation curves and temperature windows for controlled deposition rates. Any ALD process should be self-limiting in nature, exhibiting a temperature window of nominal deposition and a linear deposition rate. Meeting these criteria usually requires several ALD experiments, followed by film characterization, which are generally time, cost, and labor-intensive. Against this backdrop, we report a methodology using in situ ellipsometry to rapidly develop the ALD process for cerium oxide using Ce(iPrCp)2(N-iPr-amd) and water. The entire optimized process was realized in ten experiments of sequential pulsing as a function of temperature, requiring less than a day. In the traditional approach, tens of experiments and ex situ characterization may be required. The approach reported here generated a contour visualization of the time-temperature-thickness parameter space delineating the optimal deposition conditions. The cerium oxide deposition rate deposited in the ALD temperature window was ∼0.15 nm/cycle; the deposited film was further characterized using x-ray photoelectron spectroscopy, x-ray diffraction, and atomic force microscopy to probe the film composition and quality further.
Using unilateral stimulation to create a reference for bilateral fusion judgments
Authors: Kim Grace Hyerin , Aronoff Justin M.
Published: November 2021

Measuring binaural fusion can be challenging, especially with bilateral cochlear implant (CI) users. This study validated a technique of using unilateral stimulation to create a reference for measuring fusion. Seven bilateral CI users listened to stimuli randomly presented to the right, left, or both ears. Participants indicated the size, number, and location of the resulting image(s) they perceived. The participants had largely unitary, punctate percepts that were lateralized to the stimulated ear for unilateral stimuli. The image was centered but more diffuse when the stimuli were presented bilaterally. The results suggest unilateral stimuli can provide a reference for binaural fusion.
Long-term neuropsychiatric symptoms in spontaneous intracerebral haemorrhage survivors
Authors: Scopelliti Giuseppe , Casolla Barbara , Boulouis Grégoire , Kuchcinski Gregory , Moulin Solène , Leys Didier , Henon Hilde , Cordonnier Charlotte , Pasi Marco
Published: November 2021

Objective

Neuropsychiatric (NP) symptoms are prominent features of cognitive decline, but they have been understudied in patients with spontaneous intracerebral haemorrhage (ICH). In ICH survivors, we aimed at assessing NP symptoms prevalence and profiles, and their influence on long-term outcomes.

Methods

We analysed data from consecutive 6-month ICH survivors enrolled in the Prognosis of Intracerebral Haemorrhage study. We performed NP evaluation using the Neuropsychiatric Inventory Questionnaire. Patients underwent long-term clinical follow-up after ICH (median follow-up time 7.2 years, IQR 4.8–8.2).

Results

Out of 560 patients with ICH, 265 survived at 6 months. NP evaluation 6 months after ICH was feasible in 202 patients. NP symptoms were present in 112 patients (55%), and in 36 out of 48 patients (75%) with post-ICH dementia. Affective symptoms were present in 77 patients (38%), followed by vegetative symptoms (52 patients, 26%) and hyperactivity (47 patients, 23%). Apathy and hyperactivity were associated with post-ICH dementia and cerebral amyloid angiopathy MRI profile (all p<0.05). Apathy and hyperactivity prevailing over affective symptoms at 6-month follow-up were associated with higher risks of developing new-onset dementia (HR 5.40; 95% CI 2.27 to 12.84), while presence or severity of NP symptoms were not.

Conclusion

NP symptoms were present in more than half of 6-month ICH survivors, with higher prevalence and severity in patients with post-ICH dementia. Distinctive NP profile might be associated to cognitive status and inform on long-term dementia risk.
Time for nonilluvial Bt horizons?
Authors: Pennock Dan , Fisher Kendra
Published: November 2021

The Bt horizon is the diagnostic horizon of the Luvisolic Order in Canada. According to the Canadian System of Soil Classification (CSSC), the Bt must be formed from clay illuviation through the processes of lessivage (i.e., physical transport of clay). In a study of a Luvisol catena in the central Saskatchewan, we demonstrate that Ae/Bm horizons overlying IIBt horizons are formed in a sandy mantle overlying till (i.e., a lithological discontinuity) and that the sandy mantle contributed negligible amounts of illuvial clay despite the presence of clay skins on ped surfaces in the IIBt horizon. We extended the results of this study to the regional scale by examining sand fractions in 63 pedons of Luvisol-dominated soil associations from soil surveys in the Northern Forest Reserves (between latitudes 53°N and 55°N). Of the 63 pedons, 13 had lithological discontinuities identified in their profile description and a further 27 had discontinuities identified through shifts in the sand fractions between horizons. For the profiles with discontinuities, inherited particle size differences are a more likely cause of coarse-over-fine textural contrasts than lessivage. A regional analysis of the distribution of Luvisol-dominated associations showed distinct zonations that account, in part, for the differences in the occurrence of lithological discontinuities. Based on these results, we suggest that the criteria for Bt horizons in the CSSC should be broadened to include nonilluvial coarse-over-fine texture-contrast horizons and that the criteria for the Luvisolic order also be broadened to include these nonilluvial Bt horizons.
Half-a-century of gamma-ray astrophysics at the Max-Planck Institute for Extraterrestrial Physics
Authors: Schönfelder Volker , Greiner Jochen
Published: October 2021

Gamma-ray astronomy has been one of the prime scientific research fields of the Max-Planck Institute for Extraterrestrial Physics (MPE) from its beginning. Over the years, the entire gamma-ray energy range accessible from space was explored. The purpose of this review article is to summarise the achievements of the gamma-ray group at MPE during the last 50+ years. This covers a substantial part of the general history of space-based gamma-ray astronomy, for which both, general review articles (e.g. Pinkau in Exp Astron 5: 157, 2009; Schönfelder in AN 323: 524, 2002; Trimble in AIP Conf Proc 304: 40, 1994) and a detailed tabular list of events and missions (Leonard and Gehrels inhttps://heasarc.gsfc.nasa.gov/docs/history, version 1.0.8, 2009), have been compiled. Here, we describe the gamma-ray activities at MPE from the beginning till the present, reviewing the tight interplay between new technological developments towards new instruments and scientific progress in understanding gamma-ray sources in the sky. This covers (i) the early development of instruments and their tests on half a dozen balloon flights, (ii) the involvement in the most important space missions at the time, i.e. ESA’s COS-B satellite, NASA’s Compton Gamma-ray Observatory and Fermi Space Telescope, as well as ESA’s INTEGRAL observatory, (iii) the participation in several other missions such as TD-1, Solar Maximum Mission, or Ulysses, and (iv) the complementary ground-based optical instruments OPTIMA and GROND to enhance selected science topics (pulsars, gamma-ray bursts). With the gradual running-out of institutional support since 2010, gamma-ray astrophysics as a main research field has now come to an end at MPE.
Contact interactions: the two-dimensional case
Authors: Delll’Antonio G. F.
Published: October 2021

We prove that in two dimensions the contact interaction of two wave functions is represented by a self-adjoint operator. Together with a confining potential, this provides a stable condensate of two-particle systems. Recall that in three dimensions one has a condensate of four wave functions in contact interaction (the Bose–Einstein condensate).
aCM vector bundles on projective surfaces of nonnegative Kodaira dimension
Authors: Ballico Edoardo , Huh Sukmoon , Pons-Llopis Joan
Published: October 2021

In this paper, we contribute to the construction of families of arithmetically Cohen–Macaulay (aCM) indecomposable vector bundles on a wide range of polarized surfaces [Formula: see text] for [Formula: see text] an ample line bundle. In many cases, we show that for every positive integer [Formula: see text] there exists a family of indecomposable aCM vector bundles of rank [Formula: see text], depending roughly on [Formula: see text] parameters, and in particular they are of wild representation type. We also introduce a general setting to study the complexity of a polarized variety [Formula: see text] with respect to its category of aCM vector bundles. In many cases we construct indecomposable vector bundles on [Formula: see text] which are aCM for all ample line bundles on [Formula: see text].
D-dimensional self-gravitating lattice gas in general relativity
Authors: Bakhti Benaoumeur
Published: October 2021

Using a lattice equation of state combined with the D-dimensional Tolman–Oppenheimer–Volkoff equation and the Friedmann equations, we investigate the possibility of the formation of compact objects as well as the time evolution of the scale factor and the density profile of a self-gravitating material cluster. The numerical results show that in a ([Formula: see text])-dimensional space–time, the mass is independent of the central pressure. Hence, the formation of only compact objects with a finite constant mass similar to the white dwarf is possible. However, in a ([Formula: see text])-dimensional space–time, self-gravity leads to the formation of compact objects with a large gap of mass and the corresponding phase diagram has the same structure as the one for Neutron Star. The results also show that beyond certain critical central pressure, the star is unstable against gravitational collapse, and it may end in a black hole. Analysis of space–times of higher dimensions shows that gravity has the stronger effect in [Formula: see text] dimensions. Numerical solutions of the Friedmann equations show that the effect of the curvature of space–time increases with the increasing temperature, but decreases with the increasing dimensionality beyond [Formula: see text].
Electronic irradiation of TlInSxSe2−x (x = 1): Morphology, structure and raman scattering
Authors: Tashmetov M. Yu. , Khallokov F. K. , Ismatov N. B. , Yuldashova I. I. , Umarov S. Kh.
Published: October 2021

It is shown that the replacement of a part of sulfur atoms with selenium atoms in a TlInS2single crystal stimulates the formation of a single-phase state with a monoclinic structure (space group [Formula: see text]/[Formula: see text] in TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]). Irradiation with 2 MeV electrons and a fluence of [Formula: see text] electron/cm2of powder TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]) leads to an increase in the crystallite size from 56.5 nm to 65 nm, which is most likely associated with a decrease in the interface.

The difference between the surface morphology of the synthesized TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]) single crystal and the surface morphology of the TlInS2single crystal is established, which consists in a decrease in the height and width of the roughness in TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]). Irradiation of a TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]) single crystal with electrons with a fluence of [Formula: see text] electron/cm2does not lead to a change in the height of the tubercle on its surface, and the average value of its width increases more than ten-fold.

The identity of the peaks in the Raman spectra of the TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]) single crystal before and after its irradiation with electrons with an energy of 2 MeV and upto a fluence of [Formula: see text] electron/cm2, along with the absence of a shift of the peaks, indicates the radiation resistance of the TlInS[Formula: see text]Se[Formula: see text] ([Formula: see text]) single crystal.
Multi-Timescale Load Forecast of Large Power Customers Based on Online Data Recovery and Time Series Neural Networks
Authors: Wang Xiaotian , Duan Zihe , Liu Linqing , Li Mengyu , An Yagang , Zhou Yang
Published: October 2021

This paper presents a multi-timescale receding horizon framework for the load forecast of large power customers. The future load pattern of individual users could be very difficult to predict because of its chronological and high volatile properties. Also, the sampling of nonaggregated load data may suffer from severe information missing issues. To address these challenges, we first develop an online singular value thresholding (SVT) algorithm, which utilizes the approximate low-rank property of load data matrices to efficiently recover the missing information. Then, a combinatorial deep learning method is developed, which applies the multi-layer perception (MLP) neural network and the long short-term memory (LSTM) neural network with gated recurrent unit (GRU) to deal with the short-term and ultra-short-term load forecast, respectively. Specifically, an early stopping strategy is designed and implemented to avoid the over-fitting of model training. Moreover, the receding time window is imposed to dynamically update the data recovery and load forecast outcomes, which supports the online computing on a Spark platform. Numerical experiments on real-world load data from North China confirms the effectiveness of the proposed methodology, which can support more complex applications in embedded systems and cyber physical systems.
A Cayley graph for F2 × F2 which is not minimally almost convex
Authors: Elvey Price Andrew
Published: October 2021

We give an example of a Cayley graph [Formula: see text] for the group [Formula: see text] which is not minimally almost convex (MAC). On the other hand, the standard Cayley graph for [Formula: see text] does satisfy the falsification by fellow traveler property (FFTP), which is strictly stronger. As a result, any Cayley graph property [Formula: see text] lying between FFTP and MAC (i.e., [Formula: see text]) is dependent on the generating set. This includes the well-known properties FFTP and almost convexity, which were already known to depend on the generating set as well as Poénaru’s condition [Formula: see text] and the basepoint loop shortening property (LSP) for which dependence on the generating set was previously unknown. We also show that the Cayley graph [Formula: see text] does not have the LSP, so this property also depends on the generating set.
Minimal generating set of planar moves for surfaces embedded in the four-space
Authors: Jabłonowski Michał
Published: October 2021

We derive a minimal generating set of planar moves for diagrams of surfaces embedded in the four-space. These diagrams appear as the bonded classical unlink diagrams.
An Efficient Mixed Finite Element Perfectly Matched Layer with Optimal Parameters Selection for Two-Dimensional Time Domain Soil-Structure Interaction Analysis
Authors: Nguyen Dong Van , Kim Jaemin
Published: October 2021

Perfectly matched layer (PML) is known as one of the best methods to simulate infinite domains in many fields such as soil-structure interaction (SSI). The performance of PML is significantly affected by PML parameters selection. However, the way to select PML parameters still remains unclear. This study proposes a method for PML parameters determination for elastic wave propagation in two-dimensional (2D) media. The scaling and attenuation functions are developed in order to increase the accuracy and effectiveness of the PML. The proposed scheme is applied for a mixed PML in time domain. The finite element method (FEM) formulations of the PML are presented so that it can be easily applied to the existing codes. ABAQUS, a popular FEM code, is used for numerical applications in this study. The proposed PML is imported into ABAQUS by using a user-defined element (UEL) written in Fortran language. Six numerical analyses of SSI are implemented to prove the efficiency of the proposed PML. The numerical analyses cover many realistic problems, including free field, surface structure, and embedded structure problems. The results demonstrate the efficiency of the proposed PML in terms of the accuracy and computational cost.
Numerical Study of Thermal Effect on the Stability of Carbon Nanotubes Resting on a Viscoelastic Foundation Subjected to Magnetic Field
Authors: Heidary Zeinab , Mojra Afsaneh
Published: October 2021

Carbon nanotubes (CNTs) have emerged as efficient tools in drug delivery systems; therefore, it is essential to refer to the importance of the magnetic field, in addition to the fluid flow on the dynamic behavior of CNTs. Additionally, in such medical applications, the actual working environment of nanotube often contains temperature changes, and CNTs are surrounded by soft tissues with viscoelastic mechanical properties. In this study, the vibrational behavior of CNTs conveying magnetic-fluid flow and resting on a viscoelastic foundation is investigated under various temperature variations. To incorporate the influence of slip velocity at the nanoscale, a correction factor is employed on the basis of the Beskok–Karniadakis model. The nanotube is modeled by the Euler–Bernoulli beam theory, and governing equations of motion are derived by implementing Hamilton’s principle based on Eringen’s nonlocal elasticity theory. Results indicate that by applying a magnetic field with an intensity of 30[Formula: see text]T, the dimensionless critical flow velocity increases from 4.345 to 12.603. Also, the critical flow velocity shows an increase from 4.345 to 5.854 in the presence of a viscoelastic foundation. Furthermore, a temperature variation equal to 20[Formula: see text]K reduces the critical flow velocity dramatically from 4.345 to 1.802 at low temperatures, while an increase from 4.345 to 5.443 is observed at high temperatures. Consequently, while the magnetic field and the viscoelastic foundation affect the system stability, the temperature variation may improve or deteriorate the stability. Therefore, to plan for a medical application, the inclusion of temperature variation is required.
Acoustical Study of a Lossy Gradient-Based Sonic Crystal Using Acoustic Beamforming
Authors: Panda Debasish , Mohanty Amiya Ranjan
Published: October 2021

Sonic crystals (SCs) are unique periodic structures designed to attenuate acoustic waves in tunable frequency bands known as bandgaps. Though previous works on conventional uniform SCs show good insertion loss (IL) inside the bandgaps, this work is focused on widening their bandgaps and achieving better IL inside the bandgaps by using a gradient-based sonic crystal (GBSC). The GBSC applies property gradient to the conventional SC array by varying its basic properties, i.e., the distance between the scatterers/resonators (lattice constant), and resonator dimensions between the columns and hence the name GBSC. The design of the GBSC is backed by the results of acoustic beamforming experiments conducted over the uniform SCs of hollow scatterers and Helmholtz resonators (HRs) having two-dimensional (2D) periodicity prepared by using Polyvinyl chloride (PVC) pipes without any property gradient and their respective 2D finite element (FE) studies. The experimental and FE simulation results of the uniform SCs were found to be in good agreement and therefore, the GBSC was modeled and analyzed using FE method considering the viscothermal losses inside the resonators. The results indicated that the property gradient improves both Bragg scattering and Helmholtz resonance compared to that of the uniform SCs and therefore, the GBSC exhibits wider attenuation gaps and higher attenuation levels. An array of 30 microphones was used to conduct acoustic beamforming experiments on the uniform SCs. Beamforming was found to be an advanced and fast method to perform quick measurements on the SCs.
Investigation of Rotating Eddy Current Testing Simulation Using Simplified Model
Authors: Yang Chenkai , Ge Jiuhao , Hu Baowang
Published: October 2021

To reduce the time of simulation for rotating Eddy current testing (RECT) technique, a simplified model without modeling probe was proposed previously. However, the applicability of the simplified simulation model was unknown. In this paper, the applicability of the simplified model for the RECT technique was investigated. The application condition of the simplified model was provided by comparing it with the results of the traditional simulation model. The simplified model was suitable for the study of cracks shorter than 70% size of the uniform Eddy current induced by the probe in a traditional model or experiment. The experiment was conducted to validate the simplified model. Moreover, using the simplified model, the effects of crack depth, orientation, and exciting frequency were studied. The deeper the crack depth was, the greater peak value of [Formula: see text] signal was. The crack angle was linear with the phase of signal. The exciting frequency affected the amplitude and phase of the signal at the same time.
Effects of experimental conditions on the growth of g–C3N4 nanocones by plasma sputtering reaction deposition
Authors: Wei Yanan , Du Pengxiang , Liu Yu , Sun Jian , Ying Zhifeng , Wu Jiada , Xu Ning
Published: October 2021

[Formula: see text]-C3N4 has photocatalytic hydrogen evolution properties in the visible light spectrum so that it has been extensively studied in recent years. In this paper, crystalline [Formula: see text]-C3N4 nanocones were prepared on silicon wafers by plasma sputtering reactive deposition under different substrate pretreatment and vacuum annealing conditions. The photoluminescence (PL) spectroscopy results show that different pretreatment methods and conditions for silicon wafers will affect the growth of nanocones. Only when the surface roughness of the silicon wafer is appropriate can the well-crystalline [Formula: see text]-C3N4 nanocones with complete shape and moderate density be obtained. In addition, different annealing temperatures also affect the structures of the nanocones, and too high annealing temperatures may even destroy them.
Modeling of phase transition in fabrication of polymer-derived ceramics (PDCs)
Authors: Ma Chi , Li Yan
Published: October 2021

Polymer-derived ceramics’ (PDCs) route, which converts preceramic polymers to ceramics through heat treatment, presents a flexible and energy-efficient approach to fabricate ceramic composites with arbitrary geometries and tailorable properties. Due to the huge gaps of thermal and mechanical properties of polymers and ceramics, the current state phase composition and phase distribution largely affect the heat transfer behavior and temperature field evolution that ultimately determine the subsequent polymer decomposition and phase redistribution. In this paper, a computational framework is developed to predict the continuum-level phase transition and its effect on mechanical properties. Molecular dynamics (MD) simulations are carried out first to track the atomic structure evolution and mass loss associated with gas generation. It is found that pyrolysis temperature primarily determines the amount of gases that can be generated. Gas diffusion is triggered as a result of the non-uniform temperature field. Ceramic phase formation depends on the interplay between gas generation and gas diffusion. This computational framework allows real-time temperature field and phase composition map to be explicitly extracted. The phase composition map is incorporated into a finite element model for compression simulation. The effects of heating rate, pyrolysis temperature and pyrolysis time on mechanical response are systematically studied. Conclusions from this study can provide direct guidance for fabricating PDCs with tailored properties.
Research on Intelligent Management System of Meteorological Archives Based on Big Data Framework
Authors: Chen Huawen , Xie Jianyun , Wang Sheng Jun , Ramanathan Sakkaravarthi , Mutegeki Ronald
Published: October 2021

The era of big data, analysis, and artificial intelligence is a new trend in intelligent big data analysis. The present stage of the geoscience progress allows the Earth to be analyzed as an extremely dynamic structure of multiple elements, such as the hydrosphere, lithosphere, and atmosphere, interacting in and with others. To derive useful information from them, large quantities of observation and simulation data provided by numeric models need to be analyzed. Visualization is a critical feature of data analytics since it is a simple and swift way to evaluate the data and consider the specific aspects and mistakes of the dataset. A geographic information system (GIS), the most efficient meteorological data visualization software class, provides excellent capabilities for geospatial data manipulation. The processing architecture that can efficiently be used as a back-end for GIS by providing quick access to the data stored at remote storage nodes is described in this paper. Weather departments use various kinds of sensors for data collection such as temperature, humidity, etc. The number and speed of the sensors in each sensor complicate the data processing time. This paper seeks to provide a weather-temperature analysis big data forecast architecture based on the MapReduce algorithm. The suggested intelligent management system of meteorological archives based on big data (IMS-MABD) framework methodology could promote research and advancement of intelligent big data analysis, large data analytics, business intelligence, artificial intelligence, and data science. Intelligent management systems for meteorological archive systems based on large data frameworks could be used. Experimental findings show that the architecture created allows real-time data access and can support many simultaneous applications successfully with a performance of 98.1%.
Investigating the Cybersecurity Aspects of the Liberian Government’s Network (GovNet) as a Critical National Infrastructure
Authors: Wilkins Darren
Published: October 2021

One of the most critical national infrastructures (CNIs) in Liberia on which critical e-government services are dependent is GovNet. GovNet is the acronym for Government of Liberia’s (GoL’s) Network, and it is the conduit for connectivity and gateway to the internet for all of the Government’s over 107 Ministries, Agencies, and Commissions (MACs), as well as its e-government programs. Most of the MACs connected to GovNet run siloed ICT environments with little or no cybersecurity mechanisms in place. This paper is an investigation conducted at six MACs that are members of GovNet. The investigation identified several cybersecurity deficiencies at those MACs, due to the absence of vital dimensions or pre-requirements of cybersecurity readiness including the infrastructure (digital infrastructure), capacity (education and skills) and, governance (legal and regulatory instruments). The investigation examines previous and extant literature, conducted interviews with stakeholders of GovNet, and leverages the vast experiences of the author, who is the immediate past Managing Director of LIBTELCO. Recommendations are made for the necessary actions to be taken to remedy those deficiencies in GovNet, and the study’s contribution to the body of knowledge is indicated in the Conclusion.