1,601 research outputs found

    Towards Multi-class Object Detection in Unconstrained Remote Sensing Imagery

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    Automatic multi-class object detection in remote sensing images in unconstrained scenarios is of high interest for several applications including traffic monitoring and disaster management. The huge variation in object scale, orientation, category, and complex backgrounds, as well as the different camera sensors pose great challenges for current algorithms. In this work, we propose a new method consisting of a novel joint image cascade and feature pyramid network with multi-size convolution kernels to extract multi-scale strong and weak semantic features. These features are fed into rotation-based region proposal and region of interest networks to produce object detections. Finally, rotational non-maximum suppression is applied to remove redundant detections. During training, we minimize joint horizontal and oriented bounding box loss functions, as well as a novel loss that enforces oriented boxes to be rectangular. Our method achieves 68.16% mAP on horizontal and 72.45% mAP on oriented bounding box detection tasks on the challenging DOTA dataset, outperforming all published methods by a large margin (+6% and +12% absolute improvement, respectively). Furthermore, it generalizes to two other datasets, NWPU VHR-10 and UCAS-AOD, and achieves competitive results with the baselines even when trained on DOTA. Our method can be deployed in multi-class object detection applications, regardless of the image and object scales and orientations, making it a great choice for unconstrained aerial and satellite imagery.Comment: ACCV 201

    Study of seminal infection among an infertile male population in qom, Iran, and its effect on sperm quality

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    Background and Objectives: There are very few analysis tools to examine seminal fluid specimens, so bacterial infections on male infertility has always been the subject of discussion. These infectious processes lead to deterioration of spermato-genesis, impairment of sperm function, and/or obstruction of the seminal tract. In this study, we aimed at determining the role of bacterial infection on semen parameters including motility, count and normal morphology in infertile male patients. Materials and Methods: In this cohort study, 150 infertile males having abnormal semen parameters (study group) and 150 healthy fertile males (control group) were included. A total of 300 semen samples were collected after 3 to 5 days of sexual abstinence. Volume, pH, concentration, normal morphology, and motility were evaluated. Samples were seeded using a calibrated loop on agar and EMB plates, which were incubated overnight. The microorganisms were identified by Gram staining technique, catalase and coagulase tests. Results: The prevalence of seminal infection among infertile males in Qom was 21. Among these infected samples 61.9, 14.28, 14.28 and 9.25 were contaminated with Staphylococcus aureus, coagulase negative staphylococci, Streptococcus and Escherichia coli, respectively. All the identified bacteria except Streptococcus caused a significant decrease in sperm concentration. Sperm motility was significantly lower in E. coli contaminated samples than in the control group, and the presence of E. coli and S. aureus led to a decline in normal morphology of the sperms. Conclusion: Sperm bacterial contamination is quite frequent and could contribute to the deterioration of the sperm quality of infertile males. © 2018, Tehran University of Medical Science. All rights reserved

    Study of seminal infection among an infertile male population in qom, Iran, and its effect on sperm quality

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    Background and Objectives: There are very few analysis tools to examine seminal fluid specimens, so bacterial infections on male infertility has always been the subject of discussion. These infectious processes lead to deterioration of spermato-genesis, impairment of sperm function, and/or obstruction of the seminal tract. In this study, we aimed at determining the role of bacterial infection on semen parameters including motility, count and normal morphology in infertile male patients. Materials and Methods: In this cohort study, 150 infertile males having abnormal semen parameters (study group) and 150 healthy fertile males (control group) were included. A total of 300 semen samples were collected after 3 to 5 days of sexual abstinence. Volume, pH, concentration, normal morphology, and motility were evaluated. Samples were seeded using a calibrated loop on agar and EMB plates, which were incubated overnight. The microorganisms were identified by Gram staining technique, catalase and coagulase tests. Results: The prevalence of seminal infection among infertile males in Qom was 21. Among these infected samples 61.9, 14.28, 14.28 and 9.25 were contaminated with Staphylococcus aureus, coagulase negative staphylococci, Streptococcus and Escherichia coli, respectively. All the identified bacteria except Streptococcus caused a significant decrease in sperm concentration. Sperm motility was significantly lower in E. coli contaminated samples than in the control group, and the presence of E. coli and S. aureus led to a decline in normal morphology of the sperms. Conclusion: Sperm bacterial contamination is quite frequent and could contribute to the deterioration of the sperm quality of infertile males. © 2018, Tehran University of Medical Science. All rights reserved

    Electrical and thermal generation of spin currents by magnetic bilayer graphene

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    Ultracompact spintronic devices greatly benefit from the implementation of two-dimensional materials that provide large spin polarization of charge current together with long-distance transfer of spin information. Here spin-transport measurements in bilayer graphene evidence a strong spin–charge coupling due to a large induced exchange interaction by the proximity of an interlayer antiferromagnet (CrSBr). This results in the direct detection of the spin polarization of conductivity (up to 14%) and a spin-dependent Seebeck effect in the magnetic graphene. The efficient electrical and thermal spin–current generation is the most technologically relevant aspect of magnetism in graphene, controlled here by the antiferromagnetic dynamics of CrSBr. The high sensitivity of spin transport in graphene to the magnetization of the outermost layer of the adjacent antiferromagnet, furthermore, enables the read-out of a single magnetic sublattice. The combination of gate-tunable spin-dependent conductivity and Seebeck coefficient with long-distance spin transport in a single two-dimensional material promises ultrathin magnetic memory and sensory devices based on magnetic graphene

    Isolation and confirmation of viral nervous necrosis (VNN) disease in golden grey mullet (Liza aurata) and leaping mullet (Liza saliens) in the Iranian waters of the Caspian Sea

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    The present study was conducted on 428 moribund mullet fish samples to isolate and identify the causative agent of a mysterious acute mortality which recently occurred in wild mullets in Iranian waters of Caspian Sea, suspected to be due to viral nervous necrosis (VNN) disease. Disease investigation was carried out employing various diagnostic procedures such as virology, bacteriology, parasitology, haematology, histopathology, IFAT, IHC and nested RT-PCR. Brain and eye samples of affected fishes were collected in sterile conditions and then kept at -80 °C for cell culture isolation and nested RT-PCR detection of the causative agent. Other tissue samples were also collected and fixed for histopathology, IHC and EM examinations. CPE was observed in cell cultures at 6 days after inoculation. Nine samples were found positive with virological assay. Nested RT-PCR, performed on suspected tissues and CPE positive samples, showed that about 21 tissue samples and all the CPE positive samples were positive for VNN virus (VNNV). IFAT was selected as a confirmatory method for detecting the presence of Betanodavirus antigen, cell culture isolation results and nested RT-PCR findings. Moreover, VNNV particles with 25-30 nm in diameter were also visualized in the infected brain and retina. In pathogenicity studies, guppy fishes bathed in VNNV-infected tissue culture (10-4 TCID50) showed clinical signs similar to naturally infected mullet after 15 days post infection (dpi), with mortality rates reaching up to 100% at 30 dpi. Affected organ samples as examined by cell culture isolation, IFAT, IHC and histopathology, revealed the presence of VNNV in the guppy fishes. In conclusion, it was confirmed that VNNV was the main causative agent for the disease outbreak in mullet fish in the Caspian Sea, and this is such first official report of VNN disease from Iran

    Considerations about the implementation of an autism screening program in Iran from the viewpoints of professionals and parents: a qualitative study

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    Background: The aims of this study were to explore to explore the viewpoints of parents of children with Autism Spectrum Disorders (ASD) and professionals regarding the implementation of screening programs for ASD, to explore the challenges of the implementation of a universal screening program for ASD in Iran from their viewpoints, and, to explore their recommendations to overcome the potential challenges. Method: This qualitative study was conducted using an inductive content analysis, between June 2018 and December 2018, in East-Azerbaijan province of Iran. Data was collected through in-depth interviews and focus group discussions. The participants were purposively selected among two groups: representatives of health system and representatives of children with ASD. A sample of 32 parents and 30 professionals were recruited in this study. Results: Totally, 9 main themes and 23 sub-themes were extracted in three main areas including: viewpoints of the participants about universal screening for ASD, challenges in implementation of the universal screening program, and participants� recommendations about how to overcome the potential challenges. Main challenges in implementation of the universal screening program included: shortages of ASD screening tools, weakness of the health system, lack of coordination among the ASD service providers, and social and ethical issues. Conclusion: The parents and the professionals had different viewpoints about the implementation of ASD universal screening program in Iran. According to the professionals, there is not enough rational to implement ASD screening program for all children. However, the parents believed that universal screening program is inevitable, and it should be implemented in primary health centers during the early child-care visits. The results of this study open up unspoken issues that could help in initiating the screening program not only in Iran but also in other low- and middle-income countries as well. © 2021, The Author(s)

    Design of a Harvester for Harvesting of the Leaves and Stems of Plants in Cultivation Rows and Evaluation its Performance in the Peppermint Farm

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    IntroductionThe world today is facing the issue of population growth, which will result in food shortages. One way to supply food to this growing population is to facilitate the production of agricultural products to meet the growing demand. Medicinal plants are an important product of the agricultural sector. In Iran, manual harvesting reduces the productivity of these crops, and the use of manual harvesting poses challenges related to available manpower. The costs and time required for manual harvesting are additional obstacles. Given the importance of developing medicinal plants, designing and constructing a mechanized machine for harvesting them could improve the harvesting process.Material and MethodsIn designing the machine for harvesting medicinal plants in cultivation rows, different scenarios were examined regarding the position of the machine relative to the tractor. The advantages and disadvantages of each scenario were listed separately, and finally, the continuous placement of tractors, harvesters, and trailers was defined. One of the goals of designing this machine is to perform harvesting operations for two row spacing’s - 80 and 160 cm. To achieve this goal, mechanisms were added to the machine that allow for changing the position of the harvesting head, as well as the cutting height. Moreover, due to the sensitivity of the harvested product to soil contact, the plants should be transferred immediately after cutting. Therefore, a transfer mechanism was designed and built to move the cut products to the trailer. Independent variables, including forward speed at two levels, type of reel in two types, and cutting blade in two types, were considered. Dependent variables also included harvesting efficiency, percentage of damaged plants, and harvesting capacity.Results and DiscussionThe results of variance analysis for different treatments show that the forward speed, type of reel, and cutting blade type have an effect on harvest efficiency. The difference in harvest efficiency is significant at a 1% probability level. A star cutting blade provides higher efficiency than a 40-teeth cutting blade. The rubber reel prevents plants from falling to the ground by creating a closed space in front of the blade. However, the inner parts of the rods reel are empty, and the plant can fall to the ground. Additionally, the plant may get wrapped around the rods, causing a decrease in harvesting efficiency. Another essential parameter when identifying and evaluating a harvesting machine is crop damage. Some plants get crushed and torn due to the impact on metal components. This situation reduces the quality of the harvested product, leading to a decline in the final product's price. The star-cutting blade causes more leaf rupture. In contrast, the teeth in the 40-teeth blade are continuous, making it unlikely for the leaf to get caught between the two teeth. However, with the star blade, the distance between the two blades is large, allowing the plant to get stuck in between and re-cut.ConclusionBased on tests conducted for eight different positions of the harvester, it was observed that the G test outperformed the other tests with 85.88% harvesting efficiency, a capacity of 344.8 kg h-1, and only 1.34% peppermint leaf damage. Therefore, for harvesting similar peppermint products, we recommend using a combination of a star blade, rubber carousel, and a forward speed of 1.2 meters per second. However, new tests should be conducted on other products like lavender and those with strong stems

    Disparities in the quality of and access to services in children with autism spectrum disorders: a structural equation modeling

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    Background: Socioeconomic disparities in health and healthcare are global issues that affect both adults as well as children. Children with exceptional healthcare needs, especially those with developmental impairments, including Autism Spectrum Disorders (ASD), encounter major disparities in access to and quality of health services. However, disparities in the population of children are rarely studied. The main aim of this paper is to study the socioeconomic disparities in children with ASD by examining the association between their Social Determinants of Health (SDH) status and access to and the quality of services. Methods: This is a cross-sectional study on 202 children with ASD conducted in 2019 in two provinces including Ardabil and East-Azerbaijan, in the North-West of Iran. A structured, valid questionnaire was used to collect data on demographic, SDH status, quality of services, and access to services in a population of children with ASD aged 2�16-year-old. Around 77 participants were male and the mean age of children was 2 years and 6 months. Structural Equation Modeling (SEM) were used to assess the relationship. Results: Based on the results of this study, the overall mean scores of the quality of services, access to services, and SDH status were 61.23 (30.01), 65.91 (21.89), and 29.50 (22.32) out of 100, respectively. All the associations between the quality and access dimensions and quality (B: 0.464�0.704) and access (B: 0.265�0.726) scales were statistically significant (P < 0.001). By adjusting to covariates, the access was also significantly related to service quality (P = 0.004). Finally, the associations between SDH score with service quality (P = 0.039) and access (P < 0.001) were positively significant. Conclusions: There are socioeconomic disparities in the quality of and access to services among children with ASD, who use ASD services, in the North-West of Iran. We recommend health/medical centers, where children are diagnosed with ASD, conducting SDH screening and providing families of low-SDH status with specific information about the quality of and access to services for children with ASD. Additionally, medical universities must have a plan to routinely monitor the quality of and access to services provided for the children with low SDH. © 2021, The Author(s)
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