292 research outputs found

    Analysis and Interpretation of Ion Data Associated with Neutral Gas Releases in the Earth\u27s Ionosphere

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    Barium and strontium release experiments were conducted throughout 1991 from the Combined Release and Radiation Effects Satellite (CRRES) to study both natural and man-made disturbances in the earth\u27s ionosphere. A mass spectrometer on the spacecraft counted the Ba and Sr ions as the cloud expanded. In this study, data from the G-1 (in sunlight) and G-11b (in darkness) releases were modeled to understand the source of the ion signals. The model reproduced the Ba+ sun data well assuming photoionization (τ = 28 s) was the primary ionization mechanism. However, it was not able to account for the remaining ion data: (a) Sr has a very long photoionization time constant (τ = 1920 s) and model/data comparisons showed that the Sr ionization rate must be about 60 times greater than the photoionization rate to account for the observed signals. (b) The charge transfer ionization process between Sr/Ba and ambient O+ was not sufficient to reproduce the ionization rates for Sr sun data and Sr/Ba dark data. Processes potentially responsible for the CRRES data include charge stripping and critical velocity ionization (CW). Split peaks in the ion data were also investigated and found to be due to either an instrument sensitivity feature or a two process mechanism

    Acceptability of Sexting in Same-Sex Relationships

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    For individuals who identify as part of the LGB community, the Internet can be seen as a tool to take control of their lives, may promote self-esteem, and foster a sense of belonging. The purpose of the study was to learn about sexting practices on college campuses. It builds on the existing body of knowledge by attending specifically to sexting rather than the previous literature about engagement in sexual behavior online (see, for example, Daneback, Cooper, & Månsson, 2005). Findings indicated that sexting is viewed as more acceptable in same sex relationships as compared to heterosexual relationships

    A revision of the genus Muricea Lamouroux, 1821 (Anthozoa, Octocorallia) in the eastern Pacific. Part II

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    The species of the genus Muricea were mainly described from 1846 to 1870. After that very few contributions were published. Although the highest richness of Muricea species is in the eastern Pacific shallow waters, a comprehensive systematic study of the genus does not exist. Recently we started a taxonomic review of the genus in order to validate the status of four species previously included in the genus Eumuricea. Herein we present the second part of the Muricea revision dealing with the species-group characterised by shelf-like calyces instead of tubular-like calyces (the M. squarrosa-group). Original type material was morphologically analysed and illustrated using optical and scanning electron microscopy. Comparative character tables are provided for the genus. The taxonomic status of the species was analysed and established by designating lectotypes, alternatively by recognising a holotype by monotypy. We conclude that the genus Muricea comprises 20 valid species, including the previous four in the M. squarrosa-group. We propose 10 lectotypes, a new combination and three more species groups for the genus based on morphology: the M. fruticosa-group, M. plantaginea-group and M. austera-group.Smithsonian Tropical Research Institute/[]/STRI/PanamáUniversidad de Costa Rica/[808-A9072]/UCR/Costa RicaUniversidad de Costa Rica/[808-B2142]/UCR/Costa RicaUniversidad de Costa Rica/[810-B5159]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Ciencias del Mar y Limnología (CIMAR

    Work-Related Musculoskeletal Symptoms in Otorhinolaryngology-Head and Neck Surgery Residents

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    Objectives: Work-related musculoskeletal disorders in Saudi Arabia are not often reported in the literature. This study aimed to identify musculoskeletal symptoms among otorhinolaryngology residents in Saudi Arabia. Methods: This cross-sectional survey-based study was conducted in May 2018 and included residents registered in the Saudi Otorhinolaryngology-Head and Neck Surgery Board Training programme, Riyadh, Saudi Arabia. The Nordic Musculoskeletal Questionnaire was used to assess musculoskeletal symptoms in addition to demographic and occupational factors, including operating position and the average number of operating hours. Results: A total of 45 residents (response rate: 68.2%) completed the survey, including 33 males (73.3%) and 12 females (26.7%). Most residents (91.1%) reported at least one musculoskeletal symptom. The most commonly reported musculoskeletal over the previous 12 months were shoulder complaints (64.4%) followed by neck complaints (60%). In the short term (i.e. within seven days preceding the survey), neck complaints were more common than shoulder complaints (28.9% versus 20%). Lower back complaints were the most common cause of activity limitation (24.4%) followed by shoulder complaints (13.3%), while those with neck complaints reported it as a cause for visiting a physician (8.9%). Hip and thigh complaints were significantly more frequent among residents with operation times of eight hours or more compared to those who operating for less than eight hours (42.9% versus 5.9%; P = 0.021). Conclusion: A high incidence of shoulder, neck and lower back complaints was found in this study. Residency is an ideal time in an otorhinolaryngologist’s career to implement programmes in ergonomic best practices before bad habits are developed.Keywords: Otorhinolaryngology; Musculoskeletal Abnormalities; Symptoms and Signs; Workplace; Ergonomics; Saudi Arabia

    Metabolite characterization of different palm date varieties and the correlation with their NO inhibitory activity, texture and sweetness

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    The aim of this study was to examine the variation in metabolite constituents of five commercial varieties of date fruits; Ajwa, Safawi and Ambar which originated from Madinah, the Iranian Bam and Tunisian Deglet Noor. The differences of metabolome were inves-tigated using proton nuclear magnetic resonance (1HNMR) spectroscopy combined with multivariate data analysis (MVDA). Principal Component Analysis (PCA) revealed clear separation between the date varieties. The Tunisian Deglet Noor demonstrated distinct cluster from the rest of the palm date samples based on the metabolite composition as shown by the pattern observed in Hierarchical Clustering Analysis (HCA) and PCA. Deglet Noor exhibited a significant higher level of sucrose (d5.40) and fructose (d4.16) in comparison with the other four varieties which can be associated with the distinctive sweet taste of this variety.Dates originated from Madinah and Tunisia exhibited a contrast manner in the amount of xylose and moisture content. These two aspects may contribute towards the soft texture of Tunisian dates. All Madinah dates were found to contain phenolic compounds which were well established as great antioxidant and anti-inflammatory agent. Ajwa dates exerted greater effect in inhibiting the generation of nitric oxide (NO) from the stimulated RAW264.7 cells at 95.37% inhibition. Succinic acid was suggested to have the most significant correlation with the trend of NO inhibitory shown by the selected date palm varieties

    Non‐ossifying fibroma of the mandible: a case report and review of the literature

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    The case reported here is a large non-ossifying fibroma (NOF) of the mandible presenting in a 24-year-old male patient. The lesion was diagnosed through radiological and histopathological assessment. It remains under observation without surgical intervention, despite its large size, as the extensive surgery to remove it is not currently justifiable. Whilst common at the metaphysis of the long bones in paediatric patients, NOFs are rarely observed in the jaw bones. These benign fibrous lesions are often asymptomatic and may be an incidental radiological finding. Most NOFs of the limbs presenting in children will not require any treatment, and spontaneously resolve when growth ceases. However, regarding mandibular lesions, the majority of historical cases have been successfully treated with curettage and do not recur. Due to their scarcity, the outcomes for untreated NOFs of the gnathic bones are not reliably known. We discuss the clinical, radiological and histopathological findings for this case. A thorough literature review of previous reports of this rare entity reveals the typical characteristics and behaviour of this lesion

    Optimizing Rapid Prototype Development Through Femtosecond Laser Ablation and Finite Element Method Simulation for Enhanced Separation in Microfluidics

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    In recent years, microfluidic systems have emerged as promising tools for blood separation and analysis. However, conventional methods for prototyping microfluidic systems can be slow and expensive. In this study, we present a novel approach to rapid prototyping that combines femtosecond laser ablation and finite element method (FEM) simulation. The optimization of the prototyping process was achieved through systematic characterization of the laser ablation process and the application of FEM simulation to predict the flow behavior of the microfluidic devices. Using a dean-coupled inertial flow device (DCIFD) that comprises one channel bend and three outlets side-channels. DCIF is a phenomenon that occurs in curved microfluidic channels and is considered by the existence of inconsequential flow patterns perpendicular to the main flow direction. The DCIF can enhance the separation efficiency in microfluidic devices by inducing lateral migration of particles or cells towards specific locations along the channel. This lateral migration can be controlled by adjusting the curvature and dimensions of the channel, as well as the flow rate and properties of the fluid. Overall, DCIF can provide a valuable means of achieving efficient and high-throughput separation of particles or cells in microfluidic devices. Therefore, various microfluidics designs that contain different outlet channels were studied in this research to improve blood plasma separation efficiency. Results from imitated blood flow experiments showed positive results for fluid flow and particle separation. The study also found that incorporating three various channel widths is the key to achieving efficient plasma separation, indicating that this result could serve as a guideline for future microfluidics geometry specifications in the field of blood plasma separation. According to the FEM simulation, the highest separation percentage for both microparticle sizes was obtained by incorporating a variable outlet channel width into the same microfluidic device. The FEM simulation revealed that around 95% of the larger microparticles separated while 98% of the smaller microparticles separated. This is consistent with the imitated blood separation results, which showed that 91% of the larger microparticles separated and around 93% of the smaller microparticles were separated. Overall, our results demonstrate that the combination of femtosecond laser ablation and FEM simulation significantly improved the prototyping speed and efficiency while maintaining high blood separation performance.<br/
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