Bright Spots Research Articles

Broadband multi-wavelength properties of M87 during the 2018 EHT campaign including a very high energy flaring episode

The nearby elliptical galaxy M87 contains one of only two supermassive black holes whose emission surrounding the event horizon has been imaged by the Event Horizon Telescope (EHT). In 2018, more than two dozen multi-wavelength (MWL) facilities (from radio to gamma -ray energies) took part in the second M87 EHT campaign. The goal of this extensive MWL campaign was to better understand the physics of the accreting black hole M87*, the relationship between the inflow and inner jets, and the high-energy particle acceleration. Understanding the complex astrophysics is also a necessary first step towards performing further tests of general relativity. The MWL campaign took place in April 2018, overlapping with the EHT M87* observations. We present a new, contemporaneous spectral energy distribution (SED) ranging from radio to very high-energy (VHE) gamma -rays as well as details of the individual observations and light curves. We also conducted phenomenological modelling to investigate the basic source properties. We present the first VHE gamma -ray flare from M87 detected since 2010. The flux above 350 GeV more than doubled within a period of approx 36 hours. We find that the X-ray flux is enhanced by about a factor of two compared to 2017, while the radio and millimetre core fluxes are consistent between 2017 and 2018. We detect evidence for a monotonically increasing jet position angle that corresponds to variations in the bright spot of the EHT image. Our results show the value of continued MWL monitoring together with precision imaging for addressing the origins of high-energy particle acceleration. While we cannot currently pinpoint the precise location where such acceleration takes place, the new VHE gamma -ray flare already presents a challenge to simple one-zone leptonic emission model approaches, and it emphasises the need for combined image and spectral modelling.

Putting the Bright Spots of the COVID-19 Pandemic Response to Use

Putting the Bright Spots of the COVID-19 Pandemic Response to Use

Luminescence and dielectric investigations of crystalline niobate nanoceramics prepared through aqueous chemical process

The present study reflects the synthesis of MgNb2O6 using hydrofluoric acid via a wet chemical approach, followed by characterizations involving XRD, electron microscopy, Raman spectroscopy, optical analyses, and impedance spectroscopy. The crystallite size of the synthesized material was determined to be 44 nm through XRD analysis. The lattice parameters of MgNb2O6 a, b, and c, were found to be 14.1998 Å, 5.6844 Å, and 4.9813 Å, respectively. Raman spectroscopy identified molecular bonds ranging from 253 to 1011 cm−1, mainly indicating the presence of metal oxide bonds. EDX spectra confirmed the presence of Mg, Nb, and O atoms in the prepared ceramics, indicating phase purity. FESEM analysis revealed a grain size of approximately 48 nm, with the presence of agglomerated grains. Bright spots in the SAED pattern observed by HRTEM confirmed the crystallinity of the prepared niobate materials, with the HRTEM microstructure showing a particle size near 49 nm. The crystallite size by XRD, grain size by FESEM, and particle size by HRTEM are in accordance with each other. The direct band gap was determined to be approximately 2.76 eV using UV-Visible spectroscopy. Additionally, MgNb2O6 materials exhibited a broad and strong photoluminescence emission near 445 nm with excitation at 270 nm, possibly indicating the presence of radiative defects in the crystalline nanostructure. Furthermore, impedance studies conducted between 40 and 110 MHz demonstrated a decrease in the dielectric constant at higher frequencies, reaching 21.06 at 110 MHz. A low dielectric loss was also observed at 110 MHz. The moderate band gap and strong room-temperature photoluminescence in the visible range make magnesium niobates suitable for possible applications in optical devices. This investigation shows that a dielectric constant near 21 and low dielectric loss can be achieved in the high-frequency range around 110 MHz.

Исследование линейности цветовосприятия человека в графическом интерфейсе систем управления

The work is aimed at studying the process of human perception of visual information in conditions of interaction with a certain interface. The authors describe experimental research of the linearity of human colour perception in the graphical interface of control systems when observing colour pictograms in a conditional interface. To analyze the mechanism operation of the visual information perception, an information model of visual perception is used. Features of human perception of visual information can be of both an individual nature associated with a specific individual, and an external nature associated with the systemic interference of the operator’s direct interaction with the interface. The paper defines the factors of the study and describes the methodology for preparing stimulus material using the Processing programming language. As a tool for conducting the experiment, a software and hardware complex recording oculomotor activity Eye-tracker SMI RED 250 is used. The importance of creating effective user interfaces for control systems of complex objects and insufficient study of adapting interfaces to the features of human perception of visual information at the perceptual level of awareness determine the relevance of the study. The means of mathematical statistics process the obtained parametric data of the template for examining the stimulus material. The results got in the experiment allow concluding that the mechanism of human visual information perception, when the colour spot brightness decreases, remains sensitive to yellow colour the longest.

The Effects of Controlling Gas Escape and Bottom Current Activity on the Evolution of Pockmarks in the Northwest of the Xisha Uplift, South China Sea

Submarine pockmarks are typical indicators of submarine gas escape activity. The deep strata of the Xisha Uplift are rich in biogenic and thermogenic gas, accompanied by strong bottom current activity. Investigating the effects of controlling submarine gas escape and bottom current activity on the formation and development of pockmarks in the Xisha Uplift is significant for understanding the evolution of submarine topography and geomorphology. This study utilized high-resolution multibeam data to identify 261 submarine pockmarks in the northwest of the Xisha Uplift. These pockmarks were categorized based on their morphology into circular, elliptical, elongated, crescent-shaped, and irregular types. The diameters of pockmarks in the study area range from 0.21 to 4.96 km, with maximum depths reaching 30.88 m. Using high-resolution multi-channel seismic data, we conducted a detailed analysis of the subsurface strata characteristics of the pockmarks, identifying chaotic weak reflections, bright spots, and high-angle reflectors. We believe that deep gas in the northwest of the Xisha Uplift escapes to the seafloor through migration pathways, such as faults, fractures, and gas chimneys, resulting in the formation of submarine pockmarks. Bottom current activity has a significant impact on already-formed pockmarks. Crescent-shaped and elongated pockmarks in the Xisha Uplift are largely the result of bottom current modifications of pre-existing pockmarks.

Image enhancement optimization on bright and dark spots of retinal fundus image

Image enhancement optimization on bright and dark spots of retinal fundus image

Geophysics Bright Spots

Geophysics Bright Spots reviews a number of interesting research articles from recent issues of the journal Geophysics.

Synthesis of a novel carboxymethyl chitosan-silver - ginger nanocomposite, characterization, and antimicrobial efficacy

Over 70 % of bacterial infections are resistant to one or more of the antibiotics are generally used to eliminate infections. Silver nanoparticles (AgNPs), ginger oil, and carboxymethyl chitosan (CMC) are among the materials and the green natural products that possess antimicrobial properties. In this study, combinations of the medicinal properties of CMC, AgNPs, and ginger oil were put together in one product via the synthesis of CMC-Ag-Ginger-nanocomposite. To increase the miscibility of ginger oil -used in the synthesis-, different surfactants were applied to the synthesis aqueous medium. Thus, the nanocomposite synthesized in such way assumed a new method. In addition, the nanocomposite produced using ginger oil, silver nitrate, CMC, and surfactants assumed a new nanocomposite synthesized for the first time in this research work. The Optimum reaction conditions that brought the highest AgNPs absorbance and the formation of CMC-Ag-Ginger-nanocomposite were studied. For better miscibility of ginger oil, glycerin, Tween 80, or Egyptol were applied to the synthesis aqueous medium. AgNPs obtained were evaluated by the absorbance of the nanocomposite colloidal solution. Optimum conditions: 0.5 % (w/v) Egyptol, 0.01M AgNO3, 0.5 % (w/v) ginger oil, 3 % (w/v) carboxymethyl chitosan, 95°C for 3h. A decrease in N % of CMC-Ag-G-nanocomposite (3.04 %) compared with N % of CMC (4.03 %) confirmed the formation of the nanocomposite. TEM showed spherical shape AgNPs with size range of 8–35 nm, whereas highest count % was 12–25 nm. SAED of AgNPs exhibited ring patterns with bright spots displaying polycrystallinity which agreed with XRD. SEM of CMC-Ag-G-nanocomposite showed porous structure and well distribution of AgNPs within CMC polymer. TGA showed that CMC-Ag-G-nanocomposite is more thermally stable than CMC. CMC-Ag-G-nanocomposite showed higher antibacterial efficacy against S. Aureus and E. coli and higher antimicrobial efficacy against Aspergillus Niger and Candida albicans compared to CMC. These findings render the newly prepared nanocomposite suitable for medical and other applications.

Adaptive Segmentation of DAPI-stained, C-banded, Aggregated and Overlapping Chromosomes.

Existing algorithms for automated segmentation of chromosomes and centromeres do not work well for condensed, C-banded and DAPI-stained chromosomes and centromeres. Overlapping and aggregation, which frequently occur in metaphase spreads, introduce additional challenges to the counting of chromosomes and centromeres in the Dicentrics Chromosome Assay (DCA). In this paper, we introduce adaptive algorithms, for segmentation of difficult metaphase spreads that include overlapping and aggregated chromosomes. In order to enhance and segment chromosomes, two optimizations are done: (1) the best algorithm among several options is automatically chosen based on predefined figures of merit, (2) the algorithm is automatically optimized with a binary search to modify its parameters to achieve predefined thresholds. These algorithms are designed to separate mildly or moderately aggregated chromosomal clusters. The clusters are segmented by skeleton junctions, reduction of the overall object thickness, and the watershed algorithm. The chromosomes are characterized by rules we establish, using minimal assumptions. Centromeres are detected by detecting bright spots on the surface of the chromosomes, and then using cluster analysis and shape and intensity profiles to identify them as centromeres. High sensitivity and specificity for chromosome and centromere detection were achieved.

Bright spots of agroecology in the Netherlands: A spatial analysis of agroecological practices and income stability

ContextAgroecological practices are known to reduce environmental pressure of farming systems and increase food system resilience in tropical regions. In contrast, in the temperate climate and industrialized agricultural context of the Netherlands, agroecology use remains limited and its impacts are unknown. As agroecological systems can form a sustainable alternative to conventional farming, it is relevant to study to what extent farmers use agroecological practices in the Netherlands, potentially serving as a model for transition. ObjectiveThis study assesses spatial patterns of uptake of agroecological practices and their relationship with income resilience. MethodsUsing data from 735 Dutch farms, we created a composite Agroecology Index to quantify the extent of use of agroecological practices. The FAO's 10 Elements of Agroecology framework was used to select indicators for the index, by selecting the six of the Elements in this framework for which our dataset contained suitable data. Linear regressions explored underlying factors, such as farm size and farm type. Using an outlier analysis, bright and dark spot farms, exceeding or lagging the Dutch average, were mapped. We evaluated the effects of agroecological practices on income resilience over a 10-year period. Results and conclusionsOn a 0–100 scale, agroecology scores ranged from 16.5% to 61.1% (36.6 ± 7.0), with stark contrasts between different Elements of agroecology. Arable farms excelled in Diversity, while livestock farms performed better in Efficiency. Spatial variation was substantial, with both bright and dark spots dispersed across the country. We found highest average scores and the strongest prevalence of bright spots in the province of Flevoland, an area with an exceptional number of organic farmers. Higher agroecology scores were linked to increased income stability, independent of farm size or type. SignificanceThe methods developed in this study provide an approach to address the growing demand for evidence of the upscaling of agroecology in practice. Also, the relationships between agroecology and social and environmental outcomes from farm to regional scales can be addressed, which can guide developments towards sustainable agriculture.

Weighted ultrasound entropy imaging for HIFU ablation monitoring with improved sensitivity and contrast.

Although B-mode imaging has been widely used in ultrasound-guided high-intensity focused ultrasound (HIFU) treatment, challenges remain in improving its quality and sensitivity for monitoring the thermal dose. Recently, quantitative ultrasound (QUS) imaging has been recognized with the potential to better sense the changes in the microstructure of ablated tissues. This study proposed to use a QUS method called weighted ultrasound entropy (WUE) imaging to monitor the HIFU ablation. Based on ex-vivo and in-vivo experiments, WUE images reflecting tissue changes during HIFU treatment under different acoustic power levels (174-308W) were reconstructed with a newly established imaging framework. The performance of the proposed WUE imaging in the monitoring of HIFU treatment was compared with the corresponding B-mode images in terms of their contrast-to-noise ratios (CNRs) between the focal region and the background. It was found that HIFU irradiation with higher power generated larger WUE values in the focal region, and the bright spots grew in size as the acoustic sonication proceeded. Compared with the in-situ B-mode images, the WUE images had higher image quality in indicating lesion formation, with a 39.2%-53.4% improvement in the CNR at different stages. Meanwhile, a correlation (R=0.84) between the damage area estimated in WUE images and that measured from the dissected ex-vivo tissue samples was found. WUE imaging is more sensitive and accurate than B-mode imaging in monitoring HIFU therapy. These findings suggest that WUE imaging could be a promising technique for assisting ultrasound-guided HIFU ablation.

EMPLOYEE ENGAGEMENT OF HUMAN RESOURCES AND ITS IMPACT ON THE DEVELOPMENT OF TOURISM PERFORMANCE (AN EXPLORATORY STUDY FOR A NUMBER OF TOURISM EDUCATION INSTITUTIONS IN IRAQ)

Purpose: Diagnosing the reality and role of employee engagement in addressing the problems of reducing high performance in tourism education institutions. Theoretical framework: employee engagement is one of the relatively recent management concepts in the field of administrative and organizational literature, in addition to identifying the concept of job performance and how to raise performance through the availability of job integration for the employee. Method/design/approach: Using the analytical descriptive approach by analyzing the opinions of a sample of administrative and academic leaders in universities and tourism institutes. Results and conclusion: The employee integrated at work and his presence emotionally, cognitively and physically has a significant impact on raising and improving performance, especially in academic tourism organizations. Research practical & Social implications: In recent years, interest in the issue of functional integration has increased because it represents a bright spot for employees who care about the future of the organization and who express their willingness to invest their efforts in its favor. Originality /value :The research presents numerical indicators on the research variables to guide college leaders to raise the state of job integration and is expected to contribute to broadcasting steps on how to achieve the highest level of performance.

Holographic Einstein ring of a charged Rastall AdS black hole with bulk electromagnetic field* *Supported by the National Natural Science Foundation of China (11675140, 11705005, 12375043), the Innovation and Development Joint Foundation of Chongqing Natural Science Foundation (CSTB2022NSCQ-LZX0021), and the Basic Research Project of Science and Technology Committee of Chongqing (CSTB2023NSCQ-MSX0324)

We study the Einstein images of a charged Rastall AdS black hole (BH) within the fabric of AdS/CFT correspondence. Considering the holographic setup, we analyze the amplitude of the total response function for various values of model parameters. With an increase in parameter λ and temperature T, the amplitude of the response function decreases, while it increases with an increase in electric charge e and chemical potential μ. The influence of frequency ω also plays an important role in the bulk field, as it is found that decreasing ω leads to an increase in the periods of the waves, which means that the amplitude of the response function also depends on the wave source. The relation between T and the inverse of the horizon for various values of parameter λ is interpreted under fixed values of other involved parameters. These, in turn, affect the behavior of the response function and the Einstein ring, which may be used to differentiate the present study from previous ones. We construct the holographic images of the BH in bulk via a special optical system. The results show that the Einstein ring always appears with concentric stripes at the position of the north pole, and this ring transforms into a luminosity-deformed ring or bright light spot when the distant observer lies away from the north pole. Finally, we discuss the influence of the associated parameters on the Einstein ring radius, which is consistent with wave optics.

Indian Tourism - Emerging Opportunities, Challenges and Future Trends

Travel and tour have always been part and parcel of everyone’s life. The need for recuperation from the tensions of modern life forced people to take up tours for leisure and medical purposes. This increase in general awareness among people for travelling has created a favourable condition for the growth of the tourism sector in India. India is divinely blessed with nature, diverse geographical attractions, and destinations. The tourism sector has always been a bright spot in India, due to its growth potential and its impact on the economy. But, as every sector has its strengths, so have its weaknesses and threats. Therefore, this study takes an in-depth analysis based on secondary data about the strengths, weaknesses, threats, opportunities, and future trends of Indian Tourism. The study also tries to provide suggestions that can be considered by authorities, stakeholders, and tourism departments for the improvement of the sector.

Formation of diffuse and spark discharges between two needle electrodes with the scattering of particles

The development of a nanosecond discharge in a pin-to-pin gap filled with air at atmospheric pressure has been studied with high temporal and spatial resolutions from a breakdown start to the spark decay. Positive and negative nanosecond voltage pulses with an amplitude of tens of kilovolts were applied. Time-resolved images of the discharge development were taken with a four-channel Intensified Charge Coupled Device (ICCD) camera. The minimum delay between the camera channels could be as short as ≈ 0.1 ns. This made it possible to study the gap breakdown process with subnanosecond resolution. It was observed that a wide-diameter streamer develops from the high-voltage pointed electrode. The ionization processes near the grounded pin electrode started when the streamer crossed half of the gap. After bridging the gap by the streamer, a diffuse discharge was formed. The development of spark leaders from bright spots on the surface of the pointed electrodes was observed at the next stage. It was found that the rate of development of the spark leader is an order of magnitude lower than that of the wide-diameter streamer. Long thin luminous tracks were observed against the background of a discharge plasma glow. It has been established that the tracks are adjacent to brightly glowing spots on the electrodes and are associated with the flight of small particles.

A sustainable blue economy may not be possible in Tanzania without cutting emissions

Balancing blue growth with the conservation of wild species and habitats is a key challenge for global ocean management. This is exacerbated in Global South nations, such as Tanzania, where climate-driven ocean change requires delicate marine spatial planning (MSP) trade-offs to ensure climate resilience of marine resources relied upon by coastal communities. Here, we identified challenges and opportunities that climate change presents to the near-term spatial management of Tanzania's artisanal fishing sector, marine protected areas and seaweed farming. Specifically, spatial meta-analysis of climate modelling for the region was carried out to estimate the natural distribution of climate resilience in the marine resources that support these socially important sectors. We estimated changes within the next 20 and 40 years, using modelling projections forced under global emissions trajectories, as well as a wealth of GIS and habitat suitability data derived from globally distributed programmes. Multi-decadal analyses indicated that long-term climate change trends and extreme weather present important challenges to the activity of these sectors, locally and regionally. Only in few instances did we identify areas exhibiting climate resilience and opportunities for sectoral expansion. Including these climate change refugia and bright spots in effective ocean management strategies may serve as nature-based solutions: promoting adaptive capacity in some of Tanzania's most vulnerable economic sectors; creating wage-gaining opportunities that promote gender parity; and delivering some economic benefits of a thriving ocean where possible. Without curbs in global emissions, however, a bleak future may emerge for globally valuable biodiversity hosted in Tanzania, and for its coastal communities, despite the expansion of protected areas or curbs in other pressures. Growing a sustainable ocean economy in this part of the Global South remains a substantial challenge without global decarbonization.

Integrating principled innovation as a character development framework in education coursework

ABSTRACT A college of education established a research-based framework, Principled Innovation (PI), to support education professionals to consider the role character plays when innovating. Three instructors who authored this study integrated the four assets and eight practices of the PI framework into their courses and wanted to support one another in identifying bright spots for how PI was used and expanding upon them. They used a protocol they created, the Appreciative Tuning Protocol (ATP), to help one another expand on their original efforts. This study involved a triangulated, qualitative review of the three ATP meeting transcripts, natural artifacts from the courses, and their reflections. Findings revealed that all three instructors were successful in integrating PI, that all three instructors decided to integrate PI implicitly by applying the PI assets and practices in activities, and that PI supported the course learning objectives in all courses. This study has implications for other instructors who wish to utilize PI in their courses. Research is needed to determine how PI can be integrated into other higher education topics and whether the addition of PI can impact student achievement.

Tuberculosis Case Finding Using Self-Assessment Paradigm Through the E-TIBI Application in HIV Patients

Background The goal of eliminating tuberculosis has not yet shown a bright spot. Specifically for HIV patients (PLHIV), WHO has made it a special category as a pillar for eliminating tuberculosis. The tuberculosis screening has not yet reached the national target because it is carried out manually by health workers, requiring optimization following technological developments. This study aims to determine the effectiveness of tuberculosis case finding using a self-assessment paradigm in HIV patients. Methods This research was cross-sectional. The data obtained from HIV patients before and after using the E-TIBI application for 3 months each was analyzed using the compare mean independent t-test. Then the Chi-squared test was carried out on the E-TIBI screening characteristic variables. Result In total, there were 921 respondents with 148 (16%) presumptive TB. It was found that there was a significant difference (p<0.05) in the number of presumptive TB cases found in HIV patients before and after using the E-TIBI application. The person with presumptive TB showed 20 of 24 characteristic variables that were statistically significant (p<0.05). Conclusion E-TIBI can increase the tuberculosis case finding in HIV patients so it has the potential to be implemented as a screening tool in the PLHIV community.

Extensive glacitectonism and rapid deglacial fluid expulsion in the northeastern Barents Sea

High-latitude regions store large amounts of carbon trapped by ice sheets, permafrost and gas hydrates, yet joint evolution of these climate components is poorly understood. Covered by a cold-based ice-sheet during the last glaciation, the seafloor of the northeastern Barents Sea reveals one of the largest known glacitectonic provinces in the Arctic. Up to 200-m high glacitectonic landforms are cratered and overlie faults associated with ‘bright spots’ indicative of subsurface gas accumulations. However, sediment samples show low pore gas concentrations and no present-day gas seepage. We combine new observations and ice-sheet - hydrate modelling to propose that during the Late Weichselian, glacitectonism was caused by patchy substrate stiffening due to gradual growth of subglacial gas hydrates and permafrost. Ice decay led to rapid destabilisation and full drainage of shallow hydrate reservoirs and permafrost thaw, causing craterisation which was likely accompanied by large fluxes of carbon released into the water column. This study shows that these processes were more widespread across glaciated margins, also highlighting sensitivity and potential for abrupt changes of high-latitude carbon pools in response to complex interactions between the cryosphere, ocean, and solid earth.

Glass Defect Detection with Improved Data Augmentation under Total Reflection Lighting

To address the technical challenge of identifying tiny defects, especially dust and point defects, on mobile phone flat glass, an automatic optical inspection system is established. The system investigates algorithms including imaging principles, target detection models, data augmentation, foreground segmentation, and image fusion. The system builds an automatic optical inspection platform to collect glass defect samples. It illuminates the glass samples with a combined total reflection–grazing light source, collects the defect sample data, segments the background and defects of the collected data, generates the defect mask, and extracts the complete defects of the cell phone flat glass. The system then seamlessly integrates the extracted defects with a flawless background using Poisson editing and outputs the location information of the defects and the label output to automatically generate the dataset. The deep learning network YOLOv5 works as the core algorithm framework, into which the Constructive Block Attention Module and the small target detection layer are specifically added to enhance the capability of the model to detect small defects. According to the experimental results, the combined lighting effectively improves the precision of detecting dust and bright spots. Additionally, with the adoption of novel data augmentation techniques, the enhanced YOLOv5 model is capable of effectively addressing the challenges posed by inefficient sample data and non-uniform distribution, thus mitigating network generalization issues. Furthermore, this data augmentation approach facilitates the rapid adaptation of the same detection tasks to diverse environmental scenarios, enabling the expedited and efficient deployment of the model across various industrial settings. The mean average precision (MAP) of the optimal model in the validation set reached 98.36%, 2.62% higher than that of the original YOLOv5. In addition, its false acceptance rate (FAR) is 1.27%, its false rejection rate (FRR) was 2.47%, its detection speed was 64 fps, and its correct detection rate in the validation set was 98.75%, which meets the current industrial detection requirements by and large. In this way, this paper achieved the automated inspection of mobile phone flat glass with high robustness, high precision, and a low false acceptance rate and false rejection rate, significantly reducing material losses in the factories and the likelihood of error occurrence in follow-on products. This method can be applied to the multi-scale and multi-type detection of glass defects.