577 research outputs found

    The development of the chrondrocranium of ovis, together with some aspects of the development of the osteocranium

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    It is a surprise to find on surveying the literature on the development of the mammalian chondrocranium that though several authors studied the chondrocranium of various mammals, no attempt has been made to trace system - aticnlly the development of the chondrocranium of Ovis, specimens of which are so easily available.Under the modern method of investigation adopted in the present study of the chondrocranium of Ovis the following conclusions may be drawn. The chondrocranium of Ovis conforms to the generalized mammalian type and could be easily derived from the reptilian ancestors. Many features characteristic of placental mammals are clearly exhibited The following are some of the interesting features which draw attention.1) The constricted basal plate differs from the wide basal plate of reptilian origin as in Bos and Equus.2) The presence of the interorbital septum suggests the the tropibasic skull of reptilian ancestors.4) There is no processus ascendens and the ala temporalis is a separate cartilage. The presence of an outer bar of Jacobson's cartilage appears to provide an intermediate group bridging Archaeorhinata and Caenorhinata.5) There is a definite backward extension of the nasal capsule.6) The sphenethmoid commissures are slender rods, the orbito- parietal commissures are broad reminiscent of amphibian ancestors.7) The chondrocranium of Ovis conforms to the placental type of chondrocranium.8) The base of the cranium takes a long period to ossify though a cartilaginous foundation is laid early in the development.9) The basipresphenoid and the auditory capsules do not ossify till late in development.10) The Meckel's cartilage takes no part in the formation of the mandible except to serve as a supporting rod for the lamellae of the dentary

    Modeling Camera Effects to Improve Visual Learning from Synthetic Data

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    Recent work has focused on generating synthetic imagery to increase the size and variability of training data for learning visual tasks in urban scenes. This includes increasing the occurrence of occlusions or varying environmental and weather effects. However, few have addressed modeling variation in the sensor domain. Sensor effects can degrade real images, limiting generalizability of network performance on visual tasks trained on synthetic data and tested in real environments. This paper proposes an efficient, automatic, physically-based augmentation pipeline to vary sensor effects --chromatic aberration, blur, exposure, noise, and color cast-- for synthetic imagery. In particular, this paper illustrates that augmenting synthetic training datasets with the proposed pipeline reduces the domain gap between synthetic and real domains for the task of object detection in urban driving scenes

    Successful MRI-Guided Focused Ultrasound Uterine Fibroid Treatment Despite an Ostomy and Significant Abdominal Wall Scarring

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    We present a case of successful magnetic resonance imaging-guided focused ultrasound surgery (MRgFUS) of a uterine fibroid in a patient with extensive anterior abdominal wall surgical scars from two longitudinal laparotomies, a total colectomy and ileostomy. This case demonstrates that MRgFUS can be safely used in patients with an ostomy and significant abdominal wall scarring, but careful pretreatment planning and positioning during treatment is needed

    First Approximation of Population Distributions on the International Space Station

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    This paper presents an analysis of data derived from thousands of publicly available photographs showing life on the International Space Station (ISS) between 2000 and 2020. Our analysis uses crew and locational information from the photographs’ metadata to identify the distribution of different population groups—by gender, nationality, and space agency affiliation—across modules of the ISS, for the first time. Given the significance of the ISS as the most intensively inhabited space habitat to date, an international cooperative initiative involving 26 countries and five space agencies, and one of the most expensive building projects ever undertaken by humans, developing an understanding of which people are using different parts of the space station is critical for future usage of this and other stations. This study also sheds light on problems faced by future space station designers who are concerned with optimal usage of their habitats. The data from this investigation have been permanently deposited with Open Context. It is freely available for use under a Creative Commons license (CC BY 4.0) at https://doi.org/10.6078/M7668B9H

    Automated Identification of Astronauts on Board the International Space Station: A Case Study in Space Archaeology

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    We develop and apply a deep learning-based computer vision pipeline to automatically identify crew members in archival photographic imagery taken on-board the International Space Station. Our approach is able to quickly tag thousands of images from public and private photo repositories without human supervision with high degrees of accuracy, including photographs where crew faces are partially obscured. Using the results of our pipeline, we carry out a large-scale network analysis of the crew, using the imagery data to provide novel insights into the social interactions among crew during their missions

    A proposed new generation of evidence-based microsimulation models to inform global control of cervical cancer

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    Health decision models are the only available tools designed to consider the lifetime natural history of human papillomavirus (HPV) infection and pathogenesis of cervical cancer, and the estimated long-term impact of preventive interventions. Yet health decision modeling results are often considered a lesser form of scientific evidence due to the inherent needs to rely on imperfect data and make numerous assumptions and extrapolations regarding complex processes. We propose a new health decision modeling framework that de-emphasizes cytologic-colposcopic-histologic diagnoses due to their subjectivity and lack of reproducibility, relying instead on HPV type and duration of infection as the major determinants of subsequent transition probabilities. We posit that the new model health states (normal, carcinogenic HPV infection, precancer, cancer) and corollary transitions are universal, but that the probabilities of transitioning between states may vary by population. Evidence for this variability in host response to HPV infections can be inferred from HPV prevalence patterns in different regions across the lifespan, and might be linked to different average population levels of immunologic control of HPV infections. By prioritizing direct estimation of model transition probabilities from longitudinal data (and limiting reliance on model-fitting techniques that may propagate error when applied to multiple transitions), we aim to reduce the number of assumptions for greater transparency and reliability. We propose this new microsimulation model for critique and discussion, hoping to contribute to models that maximally inform efficient strategies towards global cervical cancer elimination

    Color-to-Grayscale: Does the Method Matter in Image Recognition?

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    In image recognition it is often assumed the method used to convert color images to grayscale has little impact on recognition performance. We compare thirteen different grayscale algorithms with four types of image descriptors and demonstrate that this assumption is wrong: not all color-to-grayscale algorithms work equally well, even when using descriptors that are robust to changes in illumination. These methods are tested using a modern descriptor-based image recognition framework, on face, object, and texture datasets, with relatively few training instances. We identify a simple method that generally works best for face and object recognition, and two that work well for recognizing textures

    Higher Risk for Incident Heart Failure and Cardiovascular Mortality among Community-Dwelling Octogenarians without Pneumococcal Vaccination

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    AIMS: Octogenarians have the highest incidence of heart failure (HF) that is not fully explained by traditional risk factors. We explored whether lack of pneumococcal vaccination is associated with higher risk of incident HF among octogenarians. METHODS AND RESULTS: In the Cardiovascular Health Study (CHS), 5290 community-dwelling adults, ≥65 years of age, were free of baseline HF and had data on pneumococcal vaccination. Of these, 851 were octogenarians, of whom, 593 did not receive pneumococcal vaccination. Multivariable-adjusted hazard ratios (aHR) and 95% confidence intervals (CI) for associations of lack of pneumococcal vaccination with incident HF and other outcomes during 13 years of follow-up were estimated using Cox regression models, adjusting for demographics and other HF risk factors including influenza vaccination. Octogenarians had a mean (±SD) age of 83 (±3) years; 52% were women and 17% African American. Overall, 258 participants developed HF and 662 died. Lack of pneumococcal vaccination was associated with higher relative risk of incident HF (aHR, 1.37; 95% CI, 1.01-1.85; P = 0.044). There was also higher risk for all-cause mortality (aHR, 1.23; 95% CI, 1.02-1.49; P = 0.028), which was mostly driven by cardiovascular mortality (aHR, 1.45; 95% CI, 1.06-1.98; P = 0.019). Octogenarians without pneumococcal vaccination had a trend toward higher risk of hospitalization due to pneumonia (aHR, 1.34; 95% CI, 0.99-1.81; P = 0.059). These associations were not observed among those 65-79 years of age. CONCLUSIONS: Among community-dwelling octogenarians, lack of pneumococcal vaccination was associated with a significantly higher independent risk of incident HF and mortality, and trend for higher pneumonia hospitalization

    On the Relationship between Open Access and Altmetrics

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    A new and diverse set of online metrics are emerging to capture the effects of the sharing and discussion of research articles on online platforms. In this paper, we investigate whether altmetrics differ between Open Access (OA) and Non-Open Access (NOA) articles. We define a new metric, the Open Access Altmetric Advantage, and investigate 14 online data sources (Twitter, Facebook, CiteULike, Mendeley, F1000, blogs, mainstream news outlets, Google Plus, Pinterest, Reddit, Sina Weibo, the peer review sites PubPeer and Publons, policy documents, and sites running Stack Exchange (Q&A)). In eight of the data sources investigated, we found that OA articles receive higher altmetrics than NOA articles; however, we found less significant differences when taking into consideration some influential factors such as journal, publication year, and citation count.ye

    Co3O4 Nanocrystals on Graphene as a Synergistic Catalyst for Oxygen Reduction Reaction

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    Catalysts for oxygen reduction and evolution reactions are at the heart of key renewable energy technologies including fuel cells and water splitting. Despite tremendous efforts, developing oxygen electrode catalysts with high activity at low costs remains a grand challenge. Here, we report a hybrid material of Co3O4 nanocrystals grown on reduced graphene oxide (GO) as a high-performance bi-functional catalyst for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). While Co3O4 or graphene oxide alone has little catalytic activity, their hybrid exhibits an unexpected, surprisingly high ORR activity that is further enhanced by nitrogen-doping of graphene. The Co3O4/N-doped graphene hybrid exhibits similar catalytic activity but superior stability to Pt in alkaline solutions. The same hybrid is also highly active for OER, making it a high performance non-precious metal based bi-catalyst for both ORR and OER. The unusual catalytic activity arises from synergetic chemical coupling effects between Co3O4 and graphene.Comment: published in Nature Material
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