bluuebunny/crossref_metadata_2025 huggingface dataset:
Fetal brain response to maternal inflammation requires microglia
Authors: LaMonica Ostrem Bridget Elaine , Domínguez-Iturza Nuria , Stogsdill Jeffrey A. , Faits Tyler , Kim Kwanho , Levin Joshua Z. , Arlotta Paola
Published: May 2024

In utero infection and maternal inflammation can adversely impact fetal brain development. Maternal systemic illness, even in the absence of direct fetal brain infection, is associated with an increased risk of neuropsychiatric disorders in affected offspring. The cell types mediating the fetal brain response to maternal inflammation are largely unknown, hindering the development of novel treatment strategies. Here, we show that microglia, the resident phagocytes of the brain, highly express receptors for relevant pathogens and cytokines throughout embryonic development. Using a rodent maternal immune activation (MIA) model in which polyinosinic:polycytidylic acid is injected into pregnant mice, we demonstrate long-lasting transcriptional changes in fetal microglia that persist into postnatal life. We find that MIA induces widespread gene expression changes in neuronal and non-neuronal cells; importantly, these responses are abolished by selective genetic deletion of microglia, indicating that microglia are required for the transcriptional response of other cortical cell types to MIA. These findings demonstrate that microglia play a crucial durable role in the fetal response to maternal inflammation, and should be explored as potential therapeutic cell targets.
The NLRP3 inflammasome is essential for IL-18 production in a murine model of macrophage activation syndrome
Authors: Gleeson Tara A. , Kaiser Christina , Lawrence Catherine B. , Brough David , Allan Stuart M. , Green Jack P.
Published: May 2024

Hyperinflammatory disease is associated with an aberrant immune response resulting in cytokine storm. One such instance of hyperinflammatory disease is known as macrophage activation syndrome (MAS). The pathology of MAS can be characterised by significantly elevated serum levels of interleukin-18 (IL-18) and interferon gamma (IFNγ). Given the role for IL-18 in MAS, we sought to establish the role of inflammasomes in the disease process. Using a murine model of CpG-oligonucleotide-induced MAS, we discovered that the expression of the NLRP3 inflammasome was increased and correlated with IL-18 production. Inhibition of the NLRP3 inflammasome or the downstream caspase-1 prevented MAS-mediated upregulation of IL-18 in the plasma but, interestingly, did not alleviate key features of hyperinflammatory disease including hyperferritinaemia and splenomegaly. Furthermore blockade of IL-1 receptor with its antagonist IL-1Ra did not prevent the development of CpG-induced MAS, despite being clinically effective in the treatment of MAS. These data demonstrate that, during the development of MAS, the NLRP3 inflammasome was essential for the elevation in plasma IL-18 – a key cytokine in clinical cases of MAS – but was not a driving factor in the pathogenesis of CpG-induced MAS.
Gluconeogenesis in frogs during cooling and dehydration exposure: new insights into tissue plasticity of the gluconeogenic pathway dependent on abiotic factors
Authors: de Amaral Marjoriane , Von Dentz Maiza Cristina , David Suyllieme Machado , Kucharski Luiz Carlos
Published: May 2024

Anurans undergo significant physiological changes when exposed to environmental stressors such as low temperatures and humidity. Energy metabolism and substrate management play a crucial role in their survival success. Therefore, understanding the role of the gluconeogenic pathway and demonstrating its existence in amphibians is essential. In this study, we exposed the subtropical frog Boana pulchella to cooling (−2.5°C for 24 h) and dehydration conditions (40% of body water loss), followed by recovery (24 h), and assessed gluconeogenesis activity from alanine, lactate, glycerol and glutamine in the liver, muscle and kidney. We report for the first time that gluconeogenesis activity by 14C-alanine and 14C-lactate conversion to glucose occurs in the muscle tissue of frogs, and this tissue activity is influenced by environmental conditions. Against the control group, liver gluconeogenesis from 14C-lactate and 14C-glycerol was lower during cooling and recovery (P<0.01), and gluconeogenesis from 14C-glutamine in the kidneys was also lower during cooling (P<0.05). In dehydration exposure, gluconeogenesis from 14C-lactate in the liver was lower during recovery, and that from 14C-alanine in the muscle was lower during dehydration (P<0.05). Moreover, we observed that gluconeogenesis activity and substrate preference respond differently to cold and dehydration. These findings highlight tissue-specific plasticity dependent on the nature of the encountered stressor, offering valuable insights for future studies exploring this plasticity, elucidating the importance of the gluconeogenic pathway and characterizing it in anuran physiology.
Knowledge, attitude and practices towards COVID-19 among Indian medical undergraduates: a questionnaire-based study
Authors: Rai Sharada , Nayak Rakshatha , Bhatt Anusha S , Vatsala Kudurugundi Basavaraju , Venkataramana Chaithra Gowthuvalli , Jain Animesh
Published: May 2024

Background The Coronavirus disease-19 (COVID-19) infection of severe acute respiratory syndrome coronavirus-2 (SARS-Cov-2) has emerged as a recent pandemic, increasing the need for epidemiological studies and studies on public health. Only some studies have evaluated the awareness of medical undergraduates in India and other countries, leading to a lack of literature. Methods This study is a descriptive cross-sectional questionnaire-based study conducted in Kasturba Medical College, Mangalore, India, between June to August 2020. An online survey using Google Forms was circulated among undergraduate medical students in India by a convenient sampling method for data collection. Descriptive analysis was derived based on frequencies and percentages, and the association with age, gender, and year of undergraduate training medical course was derived using the chi-square test. Results Altogether, 630 students from India responded to the survey, with a maximum response from students studying in the second year (38.7%). Nearly 63.85% of responders identified themselves as females. Knowledge regarding the human-to-human transmission of the virus, symptoms, complications, definition of “close contact, quarantine, and its indications was adequate among the students, with more than 70% correct responses. However, one-fourth of the students needed to gain more knowledge about masks. Respiratory hygiene was poor among 24.8%. Nearly 40% of students were unaware of the management of patients with COVID-19. Conclusion There is a need for regular quality training and institutional programs on infection control of COVID-19 and other infectious diseases across all Indian medical colleges to educate undergraduate medical students, who are future healthcare professionals, thus minimizing the risk of transmission and providing standardized care for patients.
The ELIXIR Biodiversity Community: Understanding short- and long-term changes in biodiversity
Authors: Waterhouse Robert M. , Adam-Blondon Anne-Françoise , Balech Bachir , Barta Endre , Ying Shi Chua Physilia , Di Cola Valeria , Heil Katharina F. , Hughes Graham M. , Jermiin Lars S. , Kalaš Matúš , Lanfear Jerry , Pafilis Evangelos , Palagi Patricia M. , Papageorgiou Aristotelis C. , Paupério Joana , Psomopoulos Fotis , Raes Niels , Burgin Josephine , Gabaldón Toni
Published: May 2024

Biodiversity loss is now recognised as one of the major challenges for humankind to address over the next few decades. Unless major actions are taken, the sixth mass extinction will lead to catastrophic effects on the Earth’s biosphere and human health and well-being. ELIXIR can help address the technical challenges of biodiversity science, through leveraging its suite of services and expertise to enable data management and analysis activities that enhance our understanding of life on Earth and facilitate biodiversity preservation and restoration. This white paper, prepared by the ELIXIR Biodiversity Community, summarises the current status and responses, and presents a set of plans, both technical and community-oriented, that should both enhance how ELIXIR Services are applied in the biodiversity field and how ELIXIR builds connections across the many other infrastructures active in this area. We discuss the areas of highest priority, how they can be implemented in cooperation with the ELIXIR Platforms, and their connections to existing ELIXIR Communities and international consortia. The article provides a preliminary blueprint for a Biodiversity Community in ELIXIR and is an appeal to identify and involve new stakeholders.
Comparison between premortem histopathology findings in rats with and without traumatic brain injury: prospective application in forensic medicine
Authors: Suryadi Taufik , Kulsum Kulsum
Published: May 2024

Background The aim of this study was to compare pre-mortem histopathology findings in rats with and without traumatic brain injury (TBI) and its prospective application in forensic medicine. Methods This study involved 12 rats with 6 rats for each treatment group. This type of study is a laboratory experimental study with two independent groups design. The first group were rats that did not experience TBI. The second group was a group of rats with TBI. The subjects of this study were Rattus norvegicus rats, adult males, 4-8 weeks old, weighing 150-200 grams. On the 8th day after the rats experienced traumatic brain injury, the rats were then euthanized using the cervical dislocation method, after euthanasia the rats were given craniotomy and brain tissue was taken for histopathology examination. Results The description of histopathology changes in the brain organs in the group of rat without TBI found that neuron cells looked normal although there were also degeneration (21.16 ± 2.56/FV), necrosis (5.75 ± 0.98/FV), apoptosis (2.91 ± 0.80/FV), congestion ( 0.91 ± 0.49/FV), inflammatory cells (4.58 ± 1.15/FV) and hemorrhage (2.41 ± 1.11/FV). Changes in the rat traumatic brain injury group showed a lot of damage to neuron cells in the form of degeneration (48.41 ± 3.27/FV), necrosis (36.66 ± 2.89/FV), apoptosis (18.91 ± 1.24/FV), congestion (2.50 ±0.31/FV), inflammatory cells (11.41 ± 1.71/FV) and hemorrhage (10.08 ± 2.17/FV). Based on the results of statistical analysis, it can be seen that in all parameters there is a significant difference (p ≤ 0.001). Conclusions The premortem histopathology findings in rats with and without TBI which can be used for the benefit of forensic medicine in determining whether TBI is present or not. It is necessary to look more closely at the histopathology changes in the form of necrosis, apoptosis and hemorrhage.
Artificial Intelligence Model Chatgpt-4: Entrepreneur Candidate and Entrepreneurship Example
Authors: SAYGIN Muhammet , BEKMEZCİ Mustafa , DİNÇER Evren
Published: May 2024

Background Although artificial intelligence technologies are still in their infancy, it is seen that they can bring together both hope and anxiety for the future. In the research, it is focused on examining the ChatGPT-4 version, which is one of the most well-known artificial intelligence applications and claimed to have self-learning feature, within the scope of business establishment processes. Methods In this direction, the assessment questions in the Entrepreneurship Handbook, published as open access by the Small and Medium Enterprises Development Organization of Turkey, which focuses on guiding the entrepreneurial processes in Turkey and creating the perception of entrepreneurship, were combined with the artificial intelligence model ChatGPT-4 and analysed within three stages. The way of solving the questions of artificial intelligence modelling and the answers it provides have the opportunity to be compared with the entrepreneurship literature. Results It has been seen that the artificial intelligence modelling ChatGPT-4, being an outstanding entrepreneurship example itself, has succeeded in answering the questions posed in the context of 16 modules in the entrepreneurship handbook in an original way by analysing deeply. Conclusion It has also been concluded that it is quite creative in developing new alternatives to the correct answers specified in the entrepreneurship handbook. The original aspect of the research is that it is one of the pioneers of the study on artificial intelligence and entrepreneurship in literature.
Experience of observation skill workshop intervention for ophthalmologists in fellowship training
Authors: Snigdha Snigdha , Pathengay Avinash , Patel Anamika , Pandey Shefali , Mocherla Shobha , Prakasam Ruby Kala
Published: May 2024

Background To gauge the impact of an interventional workshop conducted to measure the observation skills of 34 postgraduates during induction into an ophthalmology fellowship. Methods A seven-hour workshop was conducted with the ophthalmology trainees. Trainees from the 2022 batch of ophthalmology fellowships (21 females and 13 males) were included in the study. The pre-workshop assessment comprised two non-clinical images to spot the difference and five clinical images from various subspecialties of ophthalmology. This was followed by workshop and Post workshop assessment. The pre- and post-observation grades of participants were then compared by masked ophthalmologists. The Wilcoxon signed-rank test was used to compare scores at two time points, with a p-value < 0.05 for statistical significance. Results Statistical analysis revealed that the observation skill score was significantly higher after the workshop intervention (Md = 4.00, n = 34) compared to the pre-workshop score (Md = 1.85, n = 34), p-value = 0.000. Conclusions Workshops on specific/selected foundational skills, such as observation skills and communication skills, must be integrated into the curricula of basic medical degree and specialty medicine to equip medical professionals with attentive observation and deep learning.
Study of obesity among adolescents in rural Wardha district
Authors: Bhagat Arpana , Mehendale Ashok , Muneshwar Komal
Published: May 2024

Introduction Obesity is one of the most important global issues affecting children and adolescents. The most serious lifestyle effects of adolescents’ obesity and overweight are health risks that continue into adulthood, including hypertension, dyslipidemia, hyperinsulinemia, type 2 diabetes, behavioural issues, and cardiovascular diseases. India is among the many developing nations where childhood and adolescent obesity has become a serious public health issue. Adolescence is the most important stage in physical activity, growth and development. Adolescence is a start of personal decision-making sense and the development of a customized lifestyle, including the early onset of illness, accounting for approximately 35% of the global disease burden. Many of these behavioural choices have been linked to obesity risk factors, which are mostly controlled for, such as unhealthy eating behaviour, excessive television watching, and lack of activity. While undernutrition and deficiencies in micronutrients are serious public health problems in India, obesity and overnutrition have become major problems in several areas. Aim This study aims to assess Obesity among adolescents in rural Wardha. Methods A cross-sectional study will be conducted in the rural community area of the Wardha District. A questionnaire-based face-to-face interview will be conducted with participants in the adolescent age group (10-19 years). This study aimed to identify variables associated with demographic data, age group, genetic factors, types of family, parents’ education, occupation, socioeconomic status, physical activity, and various types of food intake. Implication of study The findings of this study could be significant in the implementation of laws, programs, and initiatives to promote awareness of the associations between adolescent obesity and risk factors for lifestyle diseases. This message focuses on having a balanced diet while exercising in regular physical activity. The prevalence of obesity is reduced by this lifestyle disease.
Case Report: A rare case of Intracranial tuberculous granuloma (tuberculoma) in a 19-year -old male
Authors: Gothe Vidhata , Sharma Ranjana
Published: May 2024

A tuberculoma is a clinical sign of tuberculosis that combines tubercles into a solid mass and can resemble several forms of malignant tumors on imaging. They frequently develop in people whose original tuberculosis infection is not well controlled. When they develop intracranially, tuberculomas are symptoms of CNS tuberculosis Meningitis, radiculomyelitis, bony spinal disease, and tuberculoma/tuberculous abscess are some of the symptoms of neurological tuberculosis (TB) that can also arise intracranially or in the spinal canal. comparable to other neurological TB symptoms. The majority of the time, the diagnosis of cerebral tuberculoma is presumptive and is based on radiological findings, additional supportive TB evidence from other areas, and treatment response. However, despite adequate TB treatment and concomitant corticosteroid therapy, lesions may persist for many years, as the therapeutic response of tuberculomas is unpredictable. A 19-year-old male patient admitted to the hospital for medical treatment complained of abdominal pain, constipation, nausea and vomiting, generalized weakness, fever, and chills. According to the patient’s complaints, my patient has a history of tonic-clonic seizures dating back a month, as well as a history of typhoid fever and sickle cell disease AS pattern, both of which he had been receiving treatment at a civil hospital. At the time of admission, he had undergone a number of invasive and non-invasive investigations, including a CT brain plane and an MRI brain with contrast. Brain computed tomography (CT) revealed a persistent lacunar infarct in the left corona radiata. Acute infarct in the right corona radiata, abnormal meningeal enhancement on post-contrast with meningitis, multiple ring-enhancing lesions in the bilateral cerebral hemisphere, cerebellum, corpus callosum, and intracranial tuberculous granuloma are all revealed by MRI with contrast. left corona radiata chronic infarction.
Identifying the role of Phytomolecules in the management of liver diseases by modulating NRF2 pathway: A Scoping Review Protocol
Authors: Mili Ajay , Rajkhowa Priyobrat , Nandakumar Krishnadas , Lobo Richard
Published: May 2024

Background The Liver is a vital organ in the human body, which plays a crucial role in various physiological processes. Oxidative stress is a critical factor in the pathogenesis and progression of various liver diseases, contributing to cellular damage and dysfunction. The Liver is particularly vulnerable to the harmful effects of reactive oxygen species when the balance between their production and the body’s antioxidant defense mechanisms is disrupted. The nuclear factor erythroid 2-related factor 2 (NRF2) pathway has emerged as a promising therapeutic target for liver diseases due to its pivotal role in cellular defense against oxidative stress and inflammation. Plants have always been a source of drugs which has been used to treat various pharmacological disorders and most of its activity is due to its potential as an antioxidant. However, the specific mechanisms by which they interact with the NRF2 pathway and confer protection against liver diseases remain inadequately elucidated. Therefore, this scoping review aims to identify and analyze the existing literature pertaining to the relationship between Phytomolecules, which can modulate NRF2 and protect against liver diseases. Methods The proposed scoping review will follow the steps given by “Arksey and O’Malley and Levac et al”. Electronic databases (PubMed/MEDLINE, Embase, etc.) will be searched for recent relevant studies. A predefined criterion for the inclusion and exclusion of studies will be independently adopted by two reviewers. The review will be presented as per the “Preferred Reporting Items for Systematic Reviews and Meta-analyses Extension for Scoping Review (PRISMA-ScR)” guidelines. Conclusion The scoping review finding is expected to help understanding the role of Phytomolecules in preventing liver diseases by modulating the NRF2 pathway. Ultimately, this review will serve as a foundational step toward developing targeted interventions to improve liver health outcomes and reduce the global burden of liver diseases.
Radiator production for Pylon Fission Surface Power System through lunar In-Situ Resource Utilization
Authors: Gorokhovskaya Diana , Thomas L. Dale
Published: May 2024

Background Fission Surface Power (FSP) is currently being considered by NASA for future lunar exploration and Ultra-Safe Nuclear Corporation (USNC) is developing their Pylon FSP system. Methods This paper introduces the system focusing on the materials used for its main components. It also analyses the lunar availability of the elements required to produce these components and suggests that In-Situ Resource Utilization (ISRU) should be considered. Results As a result of the conducted analysis, it is concluded that since mass is the most important parameter when launching payload from Earth, the Pylon component with the largest mass should be considered further. The heaviest system component is the power system which, however, consists of many other components that are made from various materials. The second heaviest component is the radiator made of Titanium (Ti) metal heat pipes and Graphite Fiber Reinforced Composite (GFRC) face sheets with water as the working fluid. Since the production of Ti metal on the Moon is non-economical, Aluminum (Al) metal utilized for the International Space Station (ISS) is considered. Lunar infrastructure required to produce Al using ISRU is already available. Further analysis will be conducted in the future to look into laser 3D printing technologies. Lunar Resources Inc. is already developing techniques for Al extraction from regolith for the production of Al wires. Conclusions This research shows that all the required technologies already exist, and the next step will be to identify how the obtained Al can be manufactured into radiators. It will also be important to identify how much of the total radiator mass is Al metal to increase the fidelity of this analysis Future research will find the break-even point between the Pylon Ti radiators launched from Earth and the production of Al radiators on the Moon.
Practicum on methodology and techniques of sociological research
Authors: Sharova E. N. , Zhigunova G. V.
Published: May 2024

The textbook contains an outline of the main issues of training courses on methodology and methodology of sociological research, designed for students of Bachelor's degree programs in the areas of training "Sociology", "Social Work" and "Organization of work with youth", as well as Master's degree programs in the areas of training "Sociology", "Social Work". The manual may also be of interest to all those who organize sociological research, use sociological methods of data collection to implement professional activities in the social sphere and marketing.
Modeling Tillage Effects on Plant-Available Water by Considering Changes in Soil Structure
Authors: Samanta Sayantan , Bagnall Dianna , Ale Srinivasulu , Morgan Cristine L.S. , Molling Christine C.
Published: May 2024

Highlights

No-tillage improved plant-available water (PAW) as compared to conventional tillage, especially in dry years.

Soil structure showed 4.5 times higher impact on PAW than surface disturbance due to tillage.

Consideration of changes in soil structure is important in modeling the effects of soil management.

PALMS was found to be an effective model to assess the effects of changes in soil management on soil water.

Abstract. Management practices such as no-tillage (NT) have the potential to provide many benefits, such as reduced runoff and soil erosion and increased infiltration and soil water holding capacity. Most hydrological models that are used to simulate the effects of soil management are built based on empirical relationships between management and hydrology outcomes, and they tend to ignore or oversimplify the effects of soil structure. However, soil structure is management dependent and is a driver of water movement and storage in soil. The goal of this study was to better understand the effects of differences in soil structure between NT and conventional tillage (CT) on field-scale hydrology and plant available water (PAW). This study employed in-field measurements of soil structure in NT and CT fields in the Texas Blackland Prairies and used the Precision Agricultural-Landscape Modeling System (PALMS), which can simulate the effects of differences in soil structure. Regression analysis was performed on simulated soil water to understand the relative contributions of variations in surface roughness and macropore properties due to tillage on PAW. Results from this study showed that NT accumulated 44.8, 20.4, and 5.7 cm more PAW than CT in the top 150 cm of the soil profile during the summer growing season in the years 2006, 2008, and 2011, respectively, all of which encountered considerable dry spells. It was also found that the changes of soil structure due to tillage had about 4.5 times more impact on PAW than surface roughness. This study highlights the benefits of adopting NT over CT and showcases the importance of considering soil structure in modeling the effects of soil management on PAW. Keywords: Macropores, No-till, Preferential flow, Surface disturbance, Surface roughness, Texas Blackland Prairies.
Investigating the Physical Properties of Corn Varieties
Authors: Chowdhury Shamma Tasneem , Clementson Clairmont L. , Baidhe Emmanuel
Published: May 2024

Highlights

The effect of moisture on the physical properties of corn varied significantly with variety.

There is no comprehensive moisture model for the prediction of physical properties of corn.

The models derived from experimental data and models posited in the literature provide varying degrees of predictive accuracy.

Abstract. Several corn varieties have been developed to match short maturity seasons and increase yield for specific end use, such as ethanol production and animal feed. However, it is unclear how varietal differences influence the physical properties. Similarly, there is no certainty that these varieties adhere to the moisture engineering properties relationships recorded in the literature. This research investigated the physical properties of 10 corn hybrids at three moisture content levels (13.5%, 15.5%, and 17% w.b.). The influence of moisture content on the different geometric (equivalent diameter, geometric mean diameter, sphericity, aspect ratio, surface area, projected area, flatness ratio) and gravimetric (bulk density, true density, porosity) properties were assessed and compared with the published literature. Further, this study assessed the potential of regression-based moisture engineering properties relationship models for the prediction and description of the physical properties of corn. Predictive and descriptive comparisons indicated that, in some instances, reference models provided better predictions of the geometric and gravimetric properties of a single variety compared to pooled samples. The study models provided better predictions for the pooled samples. However, the study results confirm no one-size-fits-all moisture physical property model exists. Using existing moisture content based regression models for description and predictive purposes should be done with specific variety references. Keywords: Corn hybrids, Moisture based physical property models, Prediction of physical properties.
Multi-Layer Digital Services Increase Developers’ Requirements to Agriculture IoT Platforms
Authors: Treiber Maximilian , Grebner Simon , Spierer Samuel , Bernhardt Heinz
Published: May 2024

Highlights

Digital ecosystems in agriculture enable a new class of digital services that span over several layers of the IoT stack.

This work defines digital ecosystems in agriculture based on IoT layers and utilized technologies.

An example for a multi-layer digital service is developed, deployed, and tested using the NEVONEX Ecosystem.

Surveys reveal software providers require more platform functionalities and early iteration testing on real farms.

Abstract. In recent years, digital platforms in agriculture went through a phase of acquisitions and consolidation, where big players like agrochemical companies (Agrichems) and agricultural equipment manufacturers (OEMs) worked on expanding their technology stacks to build strategic portfolios of digital service offerings. To operate farm equipment efficiently, a combination of platforms and technologies is often needed, leading to the emergence of digital Agri-ecosystems. With the rising implementation of IoT technology, digital Agri-ecosystems enable multi-layer digital services and break down established categories (cloud-based and embedded). Content providers and developers creating those digital services face three options: aggregated cloud APIs (application programming interfaces), engineering service providers with proprietary technology stacks, and dedicated IoT ecosystems offering agnostic end-to-end workflows for development and deployment (first known example: NEVONEX). It is not yet fully understood how using an end-to-end IoT ecosystem changes developer requirements in comparison to existing solutions. Therefore, in this study, an example of a multi-layer digital service is developed and tested. Expert interviews (n = 21) explore relevant developer experiences and requirements. A consecutive survey (n = 30; NEVONEX developer conference) validates the findings. Results show that IoT- ecosystems speed up development and deployment cycles, save resources, and improve interoperability in operations. Engineering service providers remain very important players. Partner management, communication, abstraction of interfaces, testing infrastructure, and early end-user input are required by developers. In conclusion, IoT- ecosystems are beneficial for multi-layer digital service development; however, to fully satisfy developers and content providers, adjustments to platform functionalities and better testing opportunities on real farms are needed. Keywords: Automation, Digital Ecosystem, Farm equipment, NEVONEX
Some notes on phonemes and allophones in synchronic and diachronic descriptions
Authors: Cercignani Fausto
Published: May 2024

A review of the traditional procedures in analysing phones leads to the conclusion that in some cases it is the systemic distinctions and not the lexical context which are decisive in establishing phonemes. The phoneme should therefore be defined as the smallest phonological unit which is contrastive at a lexical level and/or distinctive at a systemic level. It is further argued that a new phone can acquire phonemic status when it becomes distinctive in the phonological system of the language irrespective of the context in which it occurs at a lexical level.
TÉCNICA CONSTRUTIVA: A TAIPA EM CONCEIÇÃO DO COITÉ, BAHIA
Authors: Maiara Souza de Jesus  , Ana Rita Sulz de Almeida Campos
Published: May 2024

A utilização da terra como matéria prima para construção de moradias datam de períodos muito remotos. “Foi na natureza que, há cerca de dez mil anos, foram encontrados os elementos necessários - pedra, madeira e barro - para construir as primeiras habitações” (OLENDER, 2006, apud CORDEIRO et al. 2018).
High-precision polarization imaging for three-dimensional reconstruction aided by a separate coarse depth map
Authors: Hu Yao , Xu Chuheng , Hao Qun , Zhang Shaohui , Song Ci , Liu Yiming , Wang Zichen , Lin Chao
Published: May 2024

For less-texture objects with highly reflective regions, traditional vision-based three-dimensional reconstruction techniques often fail to yield ideal results. Utilizing polarization information for reconstructing such objects is a convenient and effective method. However, relying solely on polarization information for three-dimensional reconstruction presents challenges such as ambiguity in surface normals and difficulties in normal integration. In this paper, we propose to resolve the ambiguity in polarization normals using the coarse depth as prior information under a perspective projection model. By fusing the disambiguated normal with the coarse depth, we avoid the need for normal integration. The experimental results demonstrate that our proposed algorithm improves the quality of polarization imaging, effectively restoring the details lost in the coarse depth and smoothing the areas with high reflectivity.
Feasibility of a localized mode analysis method in an SOI platform based on carrier grating
Authors: Shi Jinze , Li Changying , Wang Qing , Wan Jiajun , Liu Xiaoping
Published: May 2024

In order to measure the intensity of modes that are transmitted inside the devices on
the silicon-on-insulator (SOI) platform, researchers usually use
pre-processed couplers to make the optical modes diffract out of the
chip. However, the output couplers have an influence
(e.g., attenuation and wavelength selectivity) on the modes of
concern. Besides, as the quantity and variety of devices integrated
into the SOI platform continue to escalate, the traditional method
also shows limits on detecting devices far from the chip edge. So, is
it feasible to directly and locally measure one specific mode’s
intensity on some waveguide-based devices like the directional
coupler, polarization beam splitter, and so on? Interference of two
coherent pump beams has the capability to induce a periodic carrier
distribution in the material, thus modulating the refractive index,
effectively creating a temporary and erasable diffraction grating. In
this study, an off-chip, non-destructive, and localized detection
method based on carrier grating is proposed. A theoretical model is
developed to calculate carrier dynamics under various pump
configurations. Leveraging the finite-difference time-domain (FDTD)
method and accounting for free carrier index (FCI) and free carrier
absorption (FCA) effects, analysis of the quantitative impact of pump
intensity and radius on the diffraction efficiency of the carrier
grating in the silicon-on-insulator (SOI) platform and its far-field
divergence characteristics is provided. Ultimately, this research
contributes to a discussion on several commonly used application
scenarios and the feasibility of experimental approaches. A spatial
resolution of less than 10 µm and a diffraction efficiency of −15dB while simultaneously maintaining a
far-field divergence of 7.8° for the SOI platform are proposed at the
end of this article.
Noise and fading reduction in a phase-OTDR system using a multi-strand optical fiber sensing cable
Authors: Sami Meguellati , Hocine Medjadba , Lotfy Mokhtar Simohamed
Published: May 2024

This paper introduces an innovative architecture, to the best of our knowledge, for a phase-OTDR sensing system, employing a multi-strand optical fiber cable as the sensing element. Within the cable, the fiber strands are interconnected to form a single serpentine-shaped fiber. The key advantage of this architecture lies in its ability to enhance the detection performance of a phase-OTDR system by reducing missing alarms caused by interference fading. Additionally, noise reduction can be achieved by aggregating the sub-traces corresponding to all fiber strands. To further enhance performance, we associate the use of a multi-pulse averaging method, which involves aggregating traces obtained using multiple probe pulses with varying temporal widths. The results obtained indicate that the performance of this architecture is closely related to the number of fiber strands and the number of probe pulses used. We expect that the proposed phase-OTDR architecture is particularly well-suited for effective distributed intrusion monitoring applications in short- to medium-range sensitive infrastructures where high security is paramount.
Frequency-octupled millimeter-wave ROF system without bit walk-off effect by polarization modulators
Authors: Chen Xinqiao , Dai Siyuan , Chen Xu , Li Bin , Wang Ling
Published: May 2024

A novel, to the best of our knowledge, frequency-octupled millimeter-wave (MMW) radio
over fiber (ROF) system without bit walk-off effect, based on two
polarization modulators (PoIM) connected in parallel, is proposed. At
the central station, the downlink data signal is split into two beams;
one beam modulates the radio frequency (RF) carrier through an
electrical phase modulator (PM), the other beam is amplified by an
electrical amplifier (EA), and the two beams are combined into one,
which is used as the RF driving signal of the PoIM. By adjusting the
modulation index of the PoIMs, the phase shift of the phase shifter,
and the polarization angle of the polarizer (Pol), the main components
of the output signal from the PoIMs are ±4th-order sidebands. By adjusting the
phase modulation index of the PM and the amplification of the EA, the
downlink data signal is modulated only on the +4th-order sideband. At the base
station, a part of the −4th-order sidebands are reflected by a
fiber Bragg grating (FBG) and used as the optical carrier for uplink
for carrier reuse; the ±4th-order sidebands passing the FBG are
injected into the photodetector (PD) for photoelectrical conversion,
and the frequency-octupled MMW with the downlink data signal is
generated. The main innovation of the scheme proposed in this paper is
that the data of the uplink and the downlink is modulated on ±4th-order sidebands separately, which
eliminates the periodic fading effect and bit walk-off effect due to
fiber dispersion and greatly improves the fiber transmission distance
of the system, and also avoids the problems of DC bias drift and
extinction ratio limitation of the Mach–Zehnder modulator.
Effect of an image compression scheme on optical camera communication
Authors: Zhu Xingnan , Chen Jian , He Zhengye , Cai Anliang , Yu Changyuan
Published: May 2024

Optical camera communication (OCC) represents a subset of visible light communication with considerable potential applications in domains such as intelligent transportation systems. However, many related studies on OCC ignore the effect of image compression. Cameras typically compress captured image data to reduce the resources required to store the data. Taking Joint Photographic Experts Group (JPEG) and AV1 image file format (AVIF) compression as examples, the effect is studied based on a simplified OCC model. The simulation results indicate that image compression can achieve the effect of a low-pass filter. Image compression, especially AVIF compression, can effectively reduce the bit error ratio (BER) of the system. Compared with demodulating RAW images, the BER is reduced from 1.2×10−1 to 7.0×10−4 when the AVIF image compression ratio is approximately 140. In addition, image compression is one of the reasons for the different performance of the red, green, and blue channels.
Compact compressor based on unparallel gratings
Authors: Long Siqi , Cui Yong , Zhang Tianxiong , Wang Tao , Ji Lailin , Zhao Xiaohui , Rao Daxing , Zheng Quan , Guan Xianghe , He Ruijing , Liu Jinsheng , Gao Yanqi , Sui Zhan
Published: May 2024

The pulse compressor is one of the essential components in a high-power laser system, which is often bulky. Here, we propose a compact compressor based on a Treacy compressor with two unparallel gratings and a mirror. Two gratings provide a negative group delay dispersion, and the mirror has two functions. One is to make the beam enter the compressor twice, and the other is to make the optical path between the grating pair folded to reduce the volume of the compressor. The relation between the group delay dispersion and the incident angle in three-dimensional space is derived. The results show that a small spatial incident angle can produce a large negative dispersion when the perpendicular distance between the gratings is the same. The parameter limits of the designed structure are also discussed, and the volume of compact compressor under the simulated parameters is two-thirds of the conventional compressor when the constraints are satisfied. This work is applicable to the optimal design of grating-based compressors with different parameters.
Effects of germanium content on the optical properties of GeO2-based organic-inorganic composite films doped with azobenzene
Authors: Zhang Xuehua , Cao Jie , Wang Xingyun , Zhang Wei , Hu Fangren
Published: May 2024

Organic-inorganic composite materials have great applications in integrated optics due to their good optical performance. In this study, GeO2-based organic-inorganic composite films doped with azobenzene were prepared by combining the solgel technique and the spin-coating method. The optical waveguide properties including the refractive index and film thickness and the optical response properties of the composite films with different germanium contents have been investigated. The results indicate that the refractive index of the film increases, but the film thickness decreases as the germanium content increases. The composite film with 0.2 mol of germanium exhibits the best optical response properties. Further, the optical switching characteristics of the optimal composite film shows good stability and reversibility. The photochemical and structural properties of the film were also investigated by using Fourier transform infrared spectroscopy and thermo-gravimetric analysis. Finally, hexagonal microlens arrays were built in the film by using the UV nanoimprint technique, resulting in neatly arranged structures with good optical imaging performance.
Compact photonic crystal spectrometer with resolution beyond the fabrication precision
Authors: Sugano Ryo , Kokubu Junnosuke , Jin Shengji , Kodama Takumasa , Hofs Jocelyn J. , Zhang Jianwei , Okano Makoto , Tanabe Takasumi
Published: May 2024

We present a compact silicon photonic crystal spectrometer with a footprint of 740 × 9 µm2 and excellent wavelength resolution (∼0.01 nm at single and <0.03 nm at multiple wavelength operation) across a telecom bandwidth of 10 nm. Although our design targets a wavelength resolution of 1.6 nm, within the current state-of-the-art fabrication precision of 2 nm, we achieve a resolution that exceeds these limits. This enhanced resolution is made possible by leveraging the random localization of light within the device.
Microwave gain-assisted optical limiter in molecular magnets
Authors: Parkan Nooshin , Khoshdel Haimd , Yekta Aavval Javad , Mahmoudi Mohammad
Published: May 2024

We investigate the optical properties of a crystal of molecular magnets within the microwave frequency range. It is shown that in the presence of a static magnetic field and applying a coupling laser field in the microwave region, reverse saturable absorption in the microwave domain can be induced in molecular magnets. Notably, the intensity and detuning of the coupling laser field are shown to exert significant control over electromagnetically induced optical limiting (OL). Thus, the OL behavior can safeguard the active sensors in seekers against the saturation as they approach microwave sources. What we believe to be a novel optical limiting phenomenon is introduced, wherein the crystal amplifies noiselessly weak input microwave fields in the linear region of the optical limiter while attenuating intense input fields. Consequently, these findings suggest the potential for actively controlling radars or seekers by exploiting a gain-assisted optical limiter to detect microwave sources with weak signals. The static magnetic field, acting as a pivotal parameter, significantly influences the attainment of OL performance across a broad spectrum of microwave frequencies. We anticipate that the outcomes of this investigation could be applied in microwave photonics to enhance the ranging capabilities of missile seekers or radars via the identification of weak signal targets. Additionally, the research highlights the protective capabilities of microwave sensors against high-power microwave signals. Finally, the open aperture Z-scan technique is employed to confirm the induced gain-assisted optical limiting behavior in molecular magnets.
High-speed waveguide lateral Ge/Si avalanche photodetector for C-band and L-band
Authors: Hu Yiling , Liu Zhi , Zhu Yupeng , Liu Zhipeng , Song Zeguo , Huang Qinxing , Liu Xiangquan , Men Tao , Zhang Guangze , Zheng Jun , Zuo Yuhua , Cheng Buwen
Published: May 2024

Germanium/silicon (Ge/Si) avalanche photodiodes (APDs) have been intensively investigated and are widely used in various fields, such as near-infrared detection and quantum communication. However, existing research of Ge/Si APDs mostly focuses on a single optical communication band. The influence of wavelengths has not been studied. In this paper, we propose a lateral separate absorption multiplication (SAM) APD and conduct an in-depth research into the performance of Ge/Si APDs at different wavelengths. We reveal a significant enhancement in the performance of Ge/Si APDs at L-band (1600 nm) compared to the C-band (1550 nm). A gain-bandwidth product of 279 GHz corresponding to a gain of 18.4 and a bandwidth of 15.2 GHz are achieved at 1600 nm. Through systematic experimental design and theoretical analysis, we evaluate the mechanisms of the higher gain, providing insights into its potential applications in the field of optical communication. This study holds significant implications for expanding the application scope of Ge/Si APDs in optical communication, providing experimental support for their superior performance at higher wavelengths and potentially driving advancements in related technologies.
Continuous beam scanning by transverse mode-locking in a Pound-Drever-Hall stabilized resonator
Authors: Zwilich Michael , Fallnich Carsten
Published: May 2024

Mode-locking, i.e., the phase-locked superposition of resonator modes, enables ultrafast laser beam dynamics. Here, high-speed beam scanning at 79.6 MHz is achieved by generating sets of phase-locked transverse resonator modes. Such transverse mode-locked (TML) beams are obtained via conversion in an empty, optical resonator from incident longitudinal mode-locked beams. In this conversion scheme the modal power and phase distributions can be controlled to alter the dynamics of the emerging scanning beams. It is shown, that the Pound-Drever-Hall stabilization scheme is applicable to compound TML resonances and it is used to maintain resonance between the incident beam’s spectral components and the transverse mode resonances. This way, TML states are reliably generated and continuously emitted.
High-performance microbolometers with metal-insulator-metal plasmonic absorbers in CMOS technology
Authors: Zhou Wenbin , Lan Jiang , Guo Yaozu , Liu Jie , Liu Xiangze , Wang Ke , Yan Feng , Liao Yiming , Ji Xiaoli
Published: May 2024

The practical applications of microbolometers in CMOS technology face challenges since the thermometer layers in microbolometers are typically of low IR absorption coefficients. In this paper, we demonstrate the integration of IR metal-insulator-metal (MIM) plasmonic absorber on the CMOS resistive-type microbolometers to maximize the optical detectivity. The MIM absorbers utilize Al metals and SiO2 dielectric films in the standard CMOS process and the configuration is numerically simulated and analyzed to assess the effectiveness of high IR absorption through propagating surface plasmon (PSP) resonance and localized surface plasmon (LSP) resonance. Experimental results show that the microbolometer integrated with the MIM plasmonic absorber has a 64% improvement in detectivity (D*) compared to the one without MIM absorber in the 7-13 µm wavelength range. The detector yields a maximum D* of 2.46 × 109 cm Hz1/2/W at 9.5 µm optimally under a working current of 30 μA. This performance-enhanced microbolometer provides a pathway for achieving ultra-sensitive imaging using a simple, cost-effective manufacturing process.