4,169 research outputs found
Determining information for inclusion in a decision-support intervention for clinical trial participation : A modified Delphi approach
Peer reviewedPostprin
Effects of injury and nutrition on sediment reworking by Clymenella torquata (Annelida: Polychaeta)
Marine infaunas influence sediment chemistry, nutrient cycling, and microbial communities as they burrow, feed, defecate, and irrigate their tubes and burrows. Nonlethal tissue loss to predators or other disturbances is frequently observed in macrofaunal communities, and previous research has reported significant effects of onetime injury on animal activity. In this study, we examined the effects of injury and nutrient enrichment on sediment reworking rates of a common deposit-feeding polychaete, Clymenella torquata. Individual worms in cores were monitored in a recirculating seawater system, and their defecation and sediment mixing monitored under several experimental conditions. Worms held in control (unenriched) sediment or in homogeneously diatom-enriched sediment were injured on days 0 and 7 in a 21 d experiment. Worms held in control sediment or sediment with high surface diatom enrichment were observed in a 7 d experiment following repeated injury. Posterior segments were ablated for the injury treatments, and injury and nutrient supply treatments were crossed in all experiments. Repeated injury significantly decreased surface activities and defecation, and injured worms transported significantly less surface sediment to depth than intact worms. Microalgal enrichment at the sediment surface correlated with an increase in bioturbation; intact worms in surfaceenriched sediments were more active and more likely to hoe surface sediments to depth as evidenced by vertical profiles. These findings help explain how infaunal activities are modified by injury and food availability and can be used to improve models of bioturbation to further elucidate complex benthic community dynamics
Rubidium abundances in the globular clusters NGC 6752, NGC 1904 and NGC 104 (47 Tuc)
Large star-to-star variations of the abundances of proton-capture elements,
such as Na and O, in globular clusters (GCs) are interpreted as the effect of
internal pollution resulting from the presence of multiple stellar populations.
To better constrain this scenario we investigate the abundance distribution of
the heavy element rubidium (Rb) in NGC 6752, NGC 1904, and NGC 104 (47 Tuc).
Combining the results from our sample with those in the literature, we found
that Rb exhibits no star-to-star variations, regardless the cluster
metallicity, with the possible intriguing, though very uncertain, exception of
the metal-rich bulge cluster NGC 6388. If no star-to-star variations will be
confirmed for all GCs, it implies that the stellar source of the proton-capture
element variations must not have produced significant amounts of Rb. This
element is observed to be enhanced at extremely high levels in
intermediate-mass AGB (IM-AGB) stars in the Magellanic Clouds (i.e., at a
metallicity similar to 47 Tuc and NGC 6388). This may present a challenge to
this popular candidate polluter, unless the mass range of the observed IM-AGB
stars does not participate in the formation of the second-generation stars in
GCs. A number of possible solutions are available to resolve this conundrum,
also given that the Magellanic Clouds observations are very uncertain and may
need to be revised. The fast rotating massive stars scenario would not face
this potential problem as the slow mechanical winds of these stars during their
main-sequence phase do not carry any Rb enhancements; however, these candidates
face even bigger issues such as the production of Li and the close
over-imposition with core-collapse supernova timescales. Observations of Sr,
Rb, and Zr in metal-rich clusters such as NGC 6388 and NGC 6441 are sorely
needed to clarify the situation.Comment: Accepted for publication in The Astrophysical Journa
Classical Guitar Ensemble
Kennesaw State University School of Music presents Classical Guitar Ensemble.https://digitalcommons.kennesaw.edu/musicprograms/1400/thumbnail.jp
The GAN that Warped: Semantic Attribute Editing with Unpaired Data
Deep neural networks have recently been used to edit images with great success, in particular for faces.However, they are often limited to only being able to work at a restricted range of resolutions. Many methods are so flexible that face edits can often result in an unwanted loss of identity.This work proposes to learn how to perform semantic image edits through the application of smooth warp fields.Previous approaches that attempted to use warping for semantic edits required paired data, \ie example images of the same subject with different semantic attributes.In contrast, we employ recent advances in Generative Adversarial Networks that allow our model to be trained with unpaired data.We demonstrate face editing at very high resolutions (4k images) with a single forward pass of a deep network at a lower resolution.We also show that our edits are substantially better at preserving the subject's identity.The robustness of our approach is demonstrated by showing plausible image editing results on the Cub200 birds dataset.To our knowledge this has not been previously accomplished, due the challenging nature of the dataset
Lost to Follow-up: A Study Exploring Barriers to Care at UNC Women’s Hospital Dysplasia Clinic
Management of Cervical Intraepithelial Neoplasia (CIN) includes a long time course of surveillance in which many women are “lost to follow-up.” Inadequate management of early dysplastic changes that may progress to CIN contributes to an increased likelihood of mortality from invasive cervical cancer in the state of North Carolina. The aim of this qualitative study is to understand women’s knowledge and perceptions of cervical dysplasia in order to tailor counseling for improved follow-up. Thirteen women with varying levels of cytological abnormalities from pap smear screening were interviewed prior to their colposcopy appointment at a referral hospital. In addition to recalling significant anxiety and fear about the possibility of cancer, women exhibited an unexpected lack of knowledge about cervical dysplasia and human papilloma virus (HPV) despite counseling at previous clinics. Financial and cost barriers were less significant to seeking care than understanding of prognosis. This study reveals an opportunity for better pre-testing and pre-screening counseling about the causal role of HPV and the potential disease course following cytological abnormalities to increase women’s likelihood of referral follow-up.Master of Science in Public Healt
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Nanoindentation of Bio- and Geo-mineralized Composites: Contribution of Microstructure and Composition
Bio-mineralized composite tissues, such as bone and teeth, are heterogeneous in both mineral composition and crystallinity. These tissues are altered throughout life by aging, wear, microfracture, and various disease states (e.g., osteoporosis), and are then further altered geologically after death by fossilization to create geo-mineralized tissues. Bone and enamel exhibit a wide range of mechanical responses at nanometer-length scales, where large-scale porosity and macro-structural variation are not factors. Some variability seen in mineralized tissues can be attributed to the amount of mineral; where a general increase in mechanical properties occurs with increasing mineral volume fraction. However, a large range of modulus values for bone is observed at a constant mineral content indicating that both the composition and microstructure play a vital role in the nanomechanical response. This dissertation is aimed at understanding the nanomechanical properties of these heterogeneous mineralized composites in order to elucidate the interplay between composition, microstructure, and tissue mechanical behavior.
A combined approach using nanoindentation testing and complimentary techniques, such as X-ray diffraction, Fourier transform infrared spectroscopy, and quantitative backscattered electron microscopy (qBSE) are used to investigate the effect of variations in crystallography, microstructure, and mineral composition on the nanomechanical properties of these materials. Further, development of novel qBSE glass standards allow for site-matched measurement of mineral volume fraction and nanomechanical properties. Additionally, a finite element analysis (FEA) allows for isolation of individual parameters and their contribution to the nanomechanical properties. The relative contribution of the composition and microstructure are explored through two experimental model systems of bone fossilization and lemur enamel.
In fossilization, or diagenesis, composition is altered over geologic time as minerals are incorporated into pore spaces within the bone. Fossilized bone samples demonstrate a larger range of mineral composition, mineral volume fraction, and crystallinity than is found in modern samples. Nanoindentation revealed that anisotropy of modern bone can be preserved in fossil bones going back at least to the early Eocene (approximately 50 million years). Further, both increased crystallinity and density correlated with increased modulus values, suggesting that size of bioapatite crystals contribute to the mechanical properties. Nanoindentation is useful in investigating tissue-level diagenesis in bone, and can provide insight into the functional significance of mineralized tissues even after diagenesis has occurred.
Variations in microstructure and mineralization were examined in the enamel of three lemur species Lemur catta, Lepilemur leucopus, Propithecus verreauxi, and Homo sapiens. Nanoindentation revealed a natural gradation of mechanical properties where a 2-12% increase in modulus and hardness correlated to increased mineral content (p \u3c 0.001) measured by qBSE. Enamel microcracking in Lemur catta resulted in a 49% reduction in nanomechcanical properties at the occlusal (or chewing) surface of the tooth. FEA modeling demonstrated a similar decrease in modulus values for indentation within 20 microns of a crack. Variations in enamel microstructure and microcracking in lemur species enables study of the interplay between tissue microstructure and nanomechanical properties, and further explores variations with diet.
The investigation of nanomechanical property dependence on microstructure and mineral composition in two experimental model systems combined with FEA is used to understand the fundamental mechanical behavior of biological heterogeneous composite materials. Understanding the interplay between material structure and function in biomineralized composites will help to elucidate the relative contributions of various factors to nanomechanical behavior and will ultimately lead to improved development of biomimetic materials
Determining items for inclusion in a decision support intervention for clinical trial participation : a modified Delphi approach
Peer reviewedPublisher PD
The GAN that Warped: Semantic Attribute Editing with Unpaired Data
Deep neural networks have recently been used to edit images with great
success, in particular for faces. However, they are often limited to only being
able to work at a restricted range of resolutions. Many methods are so flexible
that face edits can often result in an unwanted loss of identity. This work
proposes to learn how to perform semantic image edits through the application
of smooth warp fields. Previous approaches that attempted to use warping for
semantic edits required paired data, i.e. example images of the same subject
with different semantic attributes. In contrast, we employ recent advances in
Generative Adversarial Networks that allow our model to be trained with
unpaired data. We demonstrate face editing at very high resolutions (4k images)
with a single forward pass of a deep network at a lower resolution. We also
show that our edits are substantially better at preserving the subject's
identity
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