313 research outputs found
Automated Detection and Characterization of Cracks on Concrete using Laser Scanning
Accurate crack detection and characterization on concrete are essential for the maintenance, safety, and serviceability of various infrastructures. In this paper, an innovative approach was developed to automatically measure the cracks from 3D point clouds collected by a phase-shift terrestrial laser scanner (TLS) (FARO Focus3D S120). The approach integrates several techniques to characterize the cracks, which include the deviation on point normal determined using k-nearest neighbor (kNN) and principal components analysis (PCA) algorithms to identify the cracks, and principal axes and curve skeletons of cracks to determine the projected and real dimensions of cracks, respectively. The coordinate transformation was then performed to estimate the projected dimensions of cracks. Curve skeletons and cross sections of cracks were extracted to represent the real dimensions. Two cases of surface cracks were used to validate the developed approach. Because of the differences in definitions of the crack dimension in the three methods and due to the curve shape of the crack, the width and depth of cracks obtained from the cross-section method and manual measurement were close but slightly smaller than those measured by the projection algorithm; whereas the length of cracks determined by the curve-skeletons method was slightly larger than those obtained by the manual measurement and projection method. The real dimension of a crack has good agreements with real situations when compared with the results of the manual measurement and projection method
Soluble bone-derived osteopontin promotes migration and stem-like behavior of breast cancer cells
Breast cancer is a leading cause of cancer death in women, with the majority of these deaths caused by metastasis to distant organs. The most common site of breast cancer metastasis is the bone, which has been shown to provide a rich microenvironment that supports the migration and growth of breast cancer cells. Additionally, growing evidence suggests that breast cancer cells that do successfully metastasize have a stem-like phenotype including high activity of aldehyde dehydrogenase (ALDH) and/or a CD44(+)CD24(-)phenotype. In the current study, we tested the hypothesis that these ALDH (hi) CD44 (+) CD24(-)breast cancer cells interact with factors in the bone secondary organ microenvironment to facilitate metastasis. Specifically, we focused on bone-derived osteopontin and its ability to promote the migration and stem-like phenotype of breast cancer cells. Our results indicate that bone-derived osteopontin promotes the migration, tumorsphere-forming ability and colony-forming ability of whole population and ALDH hi CD44(+)CD24-breast cancer cells in bone marrow-conditioned media (an ex vivo representation of the bone microenvironment) (p \u3c= 0.05). We also demonstrate that CD44 and RGD-dependent cell surface integrins facilitate this functional response to bone-derived osteopontin (p \u3c= 0.05), potentially through activation of WNK-1 and PRAS40-related pathways. Our findings suggest that soluble bone-derived osteopontin enhances the ability of breast cancer cells to migrate to the bone and maintain a stem-like phenotype within the bone microenvironment, and this may contribute to the establishment and growth of bone metastases
Hidden Inequality: Financial Aid Information Available to College Students with Disabilities Attending Public Four-Year Institutions
College students with disabilities often encounter systems and processes that do not serve them well. Financial aid, structured in ways that can be particularly burdensome to students with disabilities, is one such system. This study used web-based content analysis of the largest public four-year institution in each state to explore how institutions explain and provide information and resources related to financial aid and whether they are equitable, consistent, and useful for students with disabilities specifically. The findings suggest that available information most often does not assist students in understanding how their disability-related needs can be supported or hindered by financial aid policies. The authors offer recommendations for practices that can improve equitable access to financial aid information
Generation of Organ-conditioned Media and Applications for Studying Organ-specific Influences on Breast Cancer Metastatic Behavior
Breast cancer preferentially metastasizes to the lymph node, bone, lung, brain and liver in breast cancer patients. Previous research efforts have focused on identifying factors inherent to breast cancer cells that are responsible for this observed metastatic pattern (termed organ tropism), however much less is known about factors present within specific organs that contribute to this process. This is in part because of a lack of in vitro model systems that accurately recapitulate the organ microenvironment. To address this, an ex vivo model system has been established that allows for the study of soluble factors present within different organ microenvironments. This model consists of generating conditioned media from organs (lymph node, bone, lung, and brain) isolated from normal athymic nude mice. The model system has been validated by demonstrating that different breast cancer cell lines display cell-line specific and organ-specific malignant behavior in response to organ-conditioned media that corresponds to their in vivo metastatic potential. This model system can be used to identify and evaluate specific organ-derived soluble factors that may play a role in the metastatic behavior of breast and other types of cancer cells, including influences on growth, migration, stem-like behavior, and gene expression, as well as the identification of potential new therapeutic targets for cancer. This is the first ex vivo model system that can be used to study organ-specific metastatic behavior in detail and evaluate the role of specific organ-derived soluble factors in driving the process of cancer metastasis
Spectroscopic analysis of Turkey red oil samples as a basis for understanding historical dyed textiles
Heritage conservation science is a valuable technique for improving understanding and the preservation of historical objects. Material analysis of heritage textiles and related materials provides information about polymer and colorant degradation, and contributes to improved conservation and display practices. The re‐creation of materials following historical processes is useful for testing analytical techniques in a field where ethical constraints often limit sampling, and to also identify potential age‐related changes relative to a fresh product. Despite the broad historical interest and industrial significance of Turkey red from the late eighteenth to the nineteenth century, little about the chemical complex of these unique textiles was understood in scientific terms. This study applied modern analysis with 1H and 13C nuclear magnetic resonance (NMR) spectroscopy to investigate the conclusions reached by nineteenth century chemists, that fatty acids were a key component of the oil treatment, a unique and vital aspect of the Turkey red dyeing process. The results show that Turkey red oil samples are composed of fatty acids which tend to polymerise over time, and that modern commercial Turkey red oil has a similar composition to historical samples and a replica sample made following a nineteenth century method. This information was used to form a hypothesis for the overall Turkey red complex on the fibre, and confirmed that the experimental work of nineteenth century chemists was theoretically accurate despite their lack of precise analytical techniques. This indicates that a re‐creation and analysis approach is effective for studying heritage materials, provided the historical practice for making the original object is taken into consideration
Androgens Regulate Prostate Cancer Cell Growth via an AMPK-PGC-1?-Mediated Metabolic Switch
Prostate cancer is the most commonly diagnosed malignancy among men in industrialized countries, accounting for the second leading cause of cancer-related deaths. While we now know that the androgen receptor (AR) is important for progression to the deadly advanced stages of the disease, it is poorly understood what AR-regulated processes drive this pathology. Here, we demonstrate that AR regulates prostate cancer cell growth via the metabolic sensor 5?-AMP-activated protein kinase (AMPK), a kinase that classically regulates cellular energy homeostasis. In patients, activation of AMPK correlated with prostate cancer progression. Using a combination of radiolabeled assays and emerging metabolomic approaches, we also show that prostate cancer cells respond to androgen treatment by increasing not only rates of glycolysis, as is commonly seen in many cancers, but also glucose and fatty acid oxidation. Importantly, this effect was dependent on androgen-mediated AMPK activity. Our results further indicate that the AMPK-mediated metabolic changes increased intracellular ATP levels and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1?)-mediated mitochondrial biogenesis, affording distinct growth advantages to the prostate cancer cells. Correspondingly, we used outlier analysis to determine that PGC-1? is overexpressed in a subpopulation of clinical cancer samples. This was in contrast to what was observed in immortalized benign human prostate cells and a testosterone-induced rat model of benign prostatic hyperplasia. Taken together, our findings converge to demonstrate that androgens can co-opt the AMPK-PGC-1? signaling cascade, a known homeostatic mechanism, to increase prostate cancer cell growth. The current study points to the potential utility of developing metabolic-targeted therapies directed towards the AMPK-PGC-1? signaling axis for the treatment of prostate cancer
On the evolutionary history of a simulated disc galaxy as seen by phylogenetic trees
© The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/Phylogenetic methods have long been used in biology, and more recently have been extended to other fields - for example, linguistics and technology - to study evolutionary histories. Galaxies also have an evolutionary history, and fall within this broad phylogenetic framework. Under the hypothesis that chemical abundances can be used as a proxy for interstellar medium's DNA, phylogenetic methods allow us to reconstruct hierarchical similarities and differences among stars - essentially a tree of evolutionary relationships and thus history. In this work, we apply phylogenetic methods to a simulated disc galaxy obtained with a chemo-dynamical code to test the approach. We found that at least 100 stellar particles are required to reliably portray the evolutionary history of a selected stellar population in this simulation, and that the overall evolutionary history is reliably preserved when the typical uncertainties in the chemical abundances are smaller than 0.08 dex. The results show that the shape of the trees are strongly affected by the age-metallicity relation, as well as the star formation history of the galaxy. We found that regions with low star formation rates produce shorter trees than regions with high star formation rates. Our analysis demonstrates that phylogenetic methods can shed light on the process of galaxy evolution.Peer reviewe
On the evolutionary history of a simulated disc galaxy as seen by phylogenetic trees
Phylogenetic methods have long been used in biology, and more recently have
been extended to other fields - for example, linguistics and technology - to
study evolutionary histories. Galaxies also have an evolutionary history, and
fall within this broad phylogenetic framework. Under the hypothesis that
chemical abundances can be used as a proxy for interstellar medium's DNA,
phylogenetic methods allow us to reconstruct hierarchical similarities and
differences among stars - essentially a tree of evolutionary relationships and
thus history. In this work, we apply phylogenetic methods to a simulated disc
galaxy obtained with a chemo-dynamical code to test the approach. We found that
at least 100 stellar particles are required to reliably portray the
evolutionary history of a selected stellar population in this simulation, and
that the overall evolutionary history is reliably preserved when the typical
uncertainties in the chemical abundances are smaller than 0.08 dex. The results
show that the shape of the trees are strongly affected by the age-metallicity
relation, as well as the star formation history of the galaxy. We found that
regions with low star formation rates produce shorter trees than regions with
high star formation rates. Our analysis demonstrates that phylogenetic methods
can shed light on the process of galaxy evolution.Comment: Accepted for publication in ApJ, October 12th 202
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