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Sample records for apparent deep stroma

  1. Deep stroma investigation by confocal microscopy

    NASA Astrophysics Data System (ADS)

    Rossi, Francesca; Tatini, Francesca; Pini, Roberto; Valente, Paola; Ardia, Roberta; Buzzonetti, Luca; Canovetti, Annalisa; Malandrini, Alex; Lenzetti, Ivo; Menabuoni, Luca

    2015-03-01

    Laser assisted keratoplasty is nowadays largely used to perform minimally invasive surgery and partial thickness keratoplasty [1-3]. The use of the femtosecond laser enables to perform a customized surgery, solving the specific problem of the single patient, designing new graft profiles and partial thickness keratoplasty (PTK). The common characteristics of the PTKs and that make them eligible respect to the standard penetrating keratoplasty, are: the preservation of eyeball integrity, a reduced risk of graft rejection, a controlled postoperative astigmatism. On the other hand, the optimal surgical results after these PTKs are related to a correct comprehension of the deep stroma layers morphology, which can help in the identification of the correct cleavage plane during surgeries. In the last years some studies were published, giving new insights about the posterior stroma morphology in adult subjects [4,5]. In this work we present a study performed on two groups of tissues: one group is from 20 adult subjects aged 59 +/- 18 y.o., and the other group is from 15 young subjects, aged 12+/-5 y.o.. The samples were from tissues not suitable for transplant in patients. Confocal microscopy and Environmental Scanning Electron Microscopy (ESEM) were used for the analysis of the deep stroma. The preliminary results of this analysis show the main differences in between young and adult tissues, enabling to improve the knowledge of the morphology and of the biomechanical properties of human cornea, in order to improve the surgical results in partial thickness keratoplasty.

  2. RESDYK—A FORTRAN program for computing apparent resistivity over an infinitely deep outcropping vertical dike

    NASA Astrophysics Data System (ADS)

    Chunduru, Raghu K.; Nagendra, R.; Patangay, N. S.

    An interactive FORTRAN IV main program "RESDYK" is given for computing apparent resistivity values resulting from a general collinear four electrode configuration oriented perpendicular to an infinitely deep, outcropping, vertical dike. The program makes use of generalized expressions for the anomalous potential so that media on either side of the dike may have different resistivities. In addition, the thickness of the dike may be small or large compared to the electrode separation. Subroutine "PROCESS" computes the potential for a two electrode (one current and one potential) configuration. By suitably combining four such potentials, the apparent resistivity which is the result of a general collinear four electrode configuration is computed by RESDYK. The results also can be expressed in a nondimensional form, convenient for preparing libraries of master curves. Test runs are appended.

  3. Apparent Anisotropic Diffusion of SF6 in a Deep Arid Unsaturated Zone

    NASA Astrophysics Data System (ADS)

    Green, C. T.; Walvoord, M. A.; Andraski, B. J.; Striegl, R. G.; Stonestrom, D. A.

    2014-12-01

    Gas transport in the unsaturated zone affects contaminant dispersal, remediation, interpretation of groundwater travel times from atmospheric tracers, and mass-budgets of environmentally important gases. Although deep unsaturated zone transport of gases is commonly treated as dominated by Fickian diffusion, previous observations at the Amargosa Desert Research Site have shown that the transport rates of various gas phase contaminants are faster than expected from standard models of diffusive transport. In this study, we use a multi-model approach to analyze results of a gas-tracer (SF6) test to clarify factors affecting gas transport in a deep unsaturated zone. Thirteen separate models with distinct diffusivity structures were calibrated to the tracer-test data. Models were compared on the basis of Akaike Information Criteria estimates of posterior model probability. The greatest posterior probability occurred for a model with significant anisotropy of diffusivity in addition to varying apparent diffusivity among vertically distributed sampling locations. Some horizontal diffusivities were greater than expected for purely diffusive transport, with values approaching free-air diffusivity (tortuosity ≈ 0.6 to 1). The magnitudes of the high apparent diffusivities were consistent with advective oscillations propagating through unsaturated-zone strata based on an analysis of barometric and unsaturated-zone air pressure time series. These results indicate that point source gases in layered unsaturated zones can spread laterally more quickly, and produce higher peak concentrations, than predicted by isotropic Fickian diffusion models.

  4. Apparent break in earthquake scaling due to path and site effects on deep borehole recordings

    USGS Publications Warehouse

    Ide, S.; Beroza, G.C.; Prejean, S.G.; Ellsworth, W.L.

    2003-01-01

    We reexamine the scaling of stress drop and apparent stress, rigidity times the ratio between seismically radiated energy to seismic moment, with earthquake size for a set of microearthquakes recorded in a deep borehole in Long Valley, California. In the first set of calculations, we assume a constant Q and solve for the corner frequency and seismic moment. In the second set of calculations, we model the spectral ratio of nearby events to determine the same quantities. We find that the spectral ratio technique, which can account for path and site effects or nonconstant Q, yields higher stress drops, particularly for the smaller events in the data set. The measurements determined from spectral ratios indicate no departure from constant stress drop scaling down to the smallest events in our data set (Mw 0.8). Our results indicate that propagation effects can contaminate measurements of source parameters even in the relatively clean recording environment of a deep borehole, just as they do at the Earth's surface. The scaling of source properties of microearthquakes made from deep borehole recordings may need to be reevaluated.

  5. Deep-sea record of impact apparently unrelated to mass extinction in the Late Triassic

    PubMed Central

    Onoue, Tetsuji; Sato, Honami; Nakamura, Tomoki; Noguchi, Takaaki; Hidaka, Yoshihiro; Shirai, Naoki; Ebihara, Mitsuru; Osawa, Takahito; Hatsukawa, Yuichi; Toh, Yosuke; Koizumi, Mitsuo; Harada, Hideo; Orchard, Michael J.; Nedachi, Munetomo

    2012-01-01

    The 34-million-year (My) interval of the Late Triassic is marked by the formation of several large impact structures on Earth. Late Triassic impact events have been considered a factor in biotic extinction events in the Late Triassic (e.g., end-Triassic extinction event), but this scenario remains controversial because of a lack of stratigraphic records of ejecta deposits. Here, we report evidence for an impact event (platinum group elements anomaly with nickel-rich magnetite and microspherules) from the middle Norian (Upper Triassic) deep-sea sediment in Japan. This includes anomalously high abundances of iridium, up to 41.5 parts per billion (ppb), in the ejecta deposit, which suggests that the iridium-enriched ejecta layers of the Late Triassic may be found on a global scale. The ejecta deposit is constrained by microfossils that suggest correlation with the 215.5-Mya, 100-km-wide Manicouagan impact crater in Canada. Our analysis of radiolarians shows no evidence of a mass extinction event across the impact event horizon, and no contemporaneous faunal turnover is seen in other marine planktons. However, such an event has been reported among marine faunas and terrestrial tetrapods and floras in North America. We, therefore, suggest that the Manicouagan impact triggered the extinction of terrestrial and marine organisms near the impact site but not within the pelagic marine realm. PMID:23129649

  6. Corneal Stroma Microfibrils

    PubMed Central

    Hanlon, Samuel D.; Behzad, Ali R.; Sakai, Lynn Y.; Burns, Alan R.

    2015-01-01

    Elastic tissue was first described well over a hundred years ago and has since been identified in nearly every part of the body. In this review, we examine elastic tissue in the corneal stroma with some mention of other ocular structures which have been more thoroughly described in the past. True elastic fibers consist of an elastin core surrounded by fibrillin microfibrils. However, the presence of elastin fibers is not a requirement and some elastic tissue is comprised of non-elastin-containing bundles of microfibrils. Fibers containing a higher relative amount of elastin are associated with greater elasticity and those without elastin, with structural support. Recently it has been shown that the microfibrils, not only serve mechanical roles, but are also involved in cell signaling through force transduction and the release of TGF-β. A well characterized example of elastin-free microfibril bundles (EFMBs) is found in the ciliary zonules which suspend the crystalline lens in the eye. Through contraction of the ciliary muscle they exert enough force to reshape the lens and thereby change its focal point. It is believed that the molecules comprising these fibers do not turn-over and yet retain their tensile strength for the life of the animal. The mechanical properties of the cornea (strength, elasticity, resiliency) would suggest that EFMBs are present there as well. However, many authors have reported that, although present during embryonic and early postnatal development, EFMBs are generally not present in adults. Serial-block-face imaging with a scanning electron microscope enabled 3D reconstruction of elements in murine corneas. Among these elements were found fibers that formed an extensive network throughout the cornea. In single sections these fibers appeared as electron dense patches. Transmission electron microscopy provided additional detail of these patches and showed them to be composed of fibrils (∼10nm diameter). Immunogold evidence clearly

  7. Large Deep-Ocean Impacts, Sea-Floor Hiatuses, and Apparent Short Term Sea-Level Changes

    NASA Astrophysics Data System (ADS)

    Hagstrum, J. T.

    2001-12-01

    Widespread discontinuities and unconformities in deep-sea sedimentary records (hiatuses) often correspond to rapid fluctuations in eustatic sea level. Such global paleoceanographic events have been attributed to vertical tectonic movements, to changes in ocean basin configuration and volume, and to glacial versus non-glacial climates. Alternatively, megatsunami waves generated by large deep-ocean impacts cause widespread erosion of the sea floor centered on the impact site. At the shoreline, run-up heights can exceed 1 km on a global scale. These high-energy events might be the source of some sea-floor hiatuses as well as stratigraphic intervals currently interpreted as short-term regression and transgression (r-t) pulses in sea level. A widespread hiatus, probable impact ejecta, ocean chemistry and sediment changes, and r-t pulse occurring at ~68-67 Ma indicate that a large oceanic impact might have preceded the Chicxulub impact by a few million years. The hiatus proximal to the Cretaceous-Tertiary (K-T) boundary is most pronounced in the northern Pacific basin and, because tsunami amplitude is proportional to water depth, could not have been caused by the shallow-water (<=100 m) Chicxulub impact at ~65 Ma. Thus K-T time likely experienced two large bolide impacts, one of which occurred in the deep ocean.

  8. Pancreatic cancer stroma: friend or foe?

    PubMed

    Gore, Jesse; Korc, Murray

    2014-06-16

    Pancreatic cancer desmoplasia is thought to confer biological aggressiveness. In this issue of Cancer Cell, Özdemir and colleagues and Rhim and colleagues demonstrate that targeting the stroma results in undifferentiated, aggressive pancreatic cancer that responds to checkpoint blockade or antiangiogenic therapy, uncovering a protective role by stroma in this cancer. PMID:24937454

  9. Tumor Stroma Manipulation By MSC.

    PubMed

    Grisendi, Giulia; Spano, Carlotta; Rossignoli, Filippo; D Souza, Naomi; Golinelli, Giulia; Fiori, Agnese; Horwitz, Edwin M; Guarneri, Valentina; Piacentini, Federico; Paolucci, Paolo; Dominici, Massimo

    2016-01-01

    Tumor stroma (TS) plays relevant roles in all steps of cancer development. We here address several fundamental aspects related with the interaction between cancer cells and their stromal counterparts. Dissecting these players is of pivotal importance to understand oncogenesis, immunoescape and drug resistance. In addition, this better comprehension will allow the introduction of novel and more effective therapeutic approaches where manipulated stromal elements may become detrimental for tumor growth. Our group and others rely on the use of multipotent mesenchymal stromal/stem cells (MSC) as anti-cancer tools, since these putative TS cell precursors can deliver potent apoptosis-inducing agents. Multimodal-armed MSC can target a variety of cancers in vitro and, when injected in vivo, they localize into tumors mediating cell death without evident toxicities to normal tissues. While several aspects of these strategies shall require further investigations, these approaches collectively indicate how TS manipulation by MSC represents a tool to influence the fate of cancer cells, creating a new generation of anti-cancer strategies. PMID:26953248

  10. Regulation of Corneal Stroma Extracellular Matrix Assembly

    PubMed Central

    Chen, Shoujun; Mienaltowski, Michael J.; Birk, David E.

    2014-01-01

    The transparent cornea is the major refractive element of the eye. A finely controlled assembly of the stromal extracellular matrix is critical to corneal function, as well as in establishing the appropriate mechanical stability required to maintain corneal shape and curvature. In the stroma, homogeneous, small diameter collagen fibrils, regularly packed with a highly ordered hierarchical organization, are essential for function. This review focuses on corneal stroma assembly and the regulation of collagen fibrillogenesis. Corneal collagen fibrillogenesis involves multiple molecules interacting in sequential steps, as well as interactions between keratocytes and stroma matrix components. The stroma has the highest collagen V:I ratio in the body. Collagen V regulates the nucleation of protofibril assembly, thus controlling the number of fibrils and assembly of smaller diameter fibrils in the stroma. The corneal stroma is also enriched in small leucine-rich proteoglycans (SLRPs) that cooperate in a temporal and spatial manner to regulate linear and lateral collagen fibril growth. In addition, the fibril-associated collagens (FACITs) such as collagen XII and collagen XIV have roles in the regulation of fibril packing and inter-lamellar interactions. A communicating keratocyte network contributes to the overall and long-range regulation of stromal extracellular matrix assembly, by creating micro-domains where the sequential steps in stromal matrix assembly are controlled. Keratocytes control the synthesis of extracellular matrix components, which interact with the keratocytes dynamically to coordinate the regulatory steps into a cohesive process. Mutations or deficiencies in stromal regulatory molecules result in altered interactions and deficiencies in both transparency and refraction, leading to corneal stroma pathobiology such as stromal dystrophies, cornea plana and keratoconus. PMID:25819456

  11. Corneal Stroma Regeneration with Acellular Corneal Stroma Sheets and Keratocytes in a Rabbit Model

    PubMed Central

    Ma, Xiao Yun; Zhang, Yun; Zhu, Dan; Lu, Yang; Zhou, Guangdong; Liu, Wei; Cao, Yilin; Zhang, Wen Jie

    2015-01-01

    Acellular corneal stroma matrix has been used for corneal stroma engineering. However, because of its compact tissue structure, regrowth of keratocytes into the scaffold is difficult. Previously, we developed a sandwich model for cartilage engineering using acellular cartilage sheets. In the present study, we tested this model for corneal stroma regeneration using acellular porcine corneal stroma (APCS) sheets and keratocytes. Porcine corneas were decellularized by NaCl treatment, and the APCS was cut into 20-μm-thick sheets. A rabbit corneal stroma defect model was created by lamellar keratoplasty and repaired by transplantation of five pieces of APCS sheets with keratocytes. Six months after transplantation, transparent corneas were present in the experimental group, which were confirmed by anterior segment optical coherence tomography examination and transmittance examination. The biomechanical properties in the experimental group were similar to those of normal cornea. Histological analyses showed an even distribution of keratocytes and well-oriented matrix in the stroma layer in the experimental group. Together, these results demonstrated that the sandwich model using acellular corneal stroma sheets and keratocytes could be potentially useful for corneal stroma regeneration. PMID:26167895

  12. Why the stroma matters in breast cancer

    PubMed Central

    Conklin, Matthew W.; Keely, Patricia J.

    2012-01-01

    Survival and recurrence rates in breast cancer are variable for common diagnoses, and therefore the biological underpinnings of the disease that determine those outcomes are yet to be fully understood. As a result, translational medicine is one of the fastest growing arenas of study in tumor biology. With advancements in genetic and imaging techniques, archived biopsies can be examined for purposes other than diagnosis. There is a great deal of evidence that points to the stroma as the major regulator of tumor progression following the initial stages of tumor formation, and the stroma may also contribute to risk factors determining tumor formation. Therefore, aspects of stromal biology are well-suited to be a focus for studies of patient outcome, where statistical differences in survival among patients provide evidence as to whether that stromal component is a signpost for tumor progression. In this review we summarize the latest research done where breast cancer patient survival was correlated with aspects of stromal biology, which have been put into four categories: reorganization of the extracellular matrix (ECM) to promote invasion, changes in the expression of stromal cell types, changes in stromal gene expression, and changes in cell biology signaling cascades to and from the stroma. PMID:22568982

  13. Reproduction in rare bathyal octopods Pteroctopus tetracirrhus and Scaeurgus unicirrhus (Cephalopoda: Octopoda) in the east Mediterranean as an apparent response to extremely oligotrophic deep seas

    NASA Astrophysics Data System (ADS)

    Laptikhovsky, Vladimir; Salman, Alp; Önsoy, Bahadir; Akalin, Meryem; Ceylan, Beytullah

    2014-10-01

    Reproductive patterns of two benthic bathyal octopods, Pteroctopus tetracirrhus and Scaeurgus unicirrhus have been studied in extremely nutrient-poor environment of the deep-sea Eastern Mediterranean. Both species were found to exhibit a reproductive tactics of producing eggs much larger than in the western part of the sea which likely results in larger hatchlings with higher viability. P. tetracirrhus exhibited a typical “deep-sea” spawning strategy of simultaneous maturation of a single batch of large eggs with atresia of excessive oocytes, whereas reproductive strategy of S. unicirrhus is particular for shelf octopodids: asynchronous maturation of numerous batches of small eggs with no obvious regulatory atresia. Existence of these two types of ovary development and utilisation of fecundity are closely related to two types of evolutionary stable reproductive strategies based on existence of either very large or very small eggs with a few species occupying the “intermediate” position.

  14. Stroma Targeting Nuclear Imaging and Radiopharmaceuticals

    PubMed Central

    Shetty, Dinesh; Jeong, Jae-Min; Shim, Hyunsuk

    2012-01-01

    Malignant transformation of tumor accompanies profound changes in the normal neighboring tissue, called tumor stroma. The tumor stroma provides an environment favoring local tumor growth, invasion, and metastatic spreading. Nuclear imaging (PET/SPECT) measures biochemical and physiologic functions in the human body. In oncology, PET/SPECT is particularly useful for differentiating tumors from postsurgical changes or radiation necrosis, distinguishing benign from malignant lesions, identifying the optimal site for biopsy, staging cancers, and monitoring the response to therapy. Indeed, PET/SPECT is a powerful, proven diagnostic imaging modality that displays information unobtainable through other anatomical imaging, such as CT or MRI. When combined with coregistered CT data, [18F]fluorodeoxyglucose ([18F]FDG)-PET is particularly useful. However, [18F]FDG is not a target-specific PET tracer. This paper will review the tumor microenvironment targeting oncologic imaging such as angiogenesis, invasion, hypoxia, growth, and homing, and also therapeutic radiopharmaceuticals to provide a roadmap for additional applications of tumor imaging and therapy. PMID:22685650

  15. Stem Cells in the Limbal Stroma.

    PubMed

    Funderburgh, James L; Funderburgh, Martha L; Du, Yiqin

    2016-04-01

    The corneal stroma contains a population of mesenchymal cells subjacent to the limbal basement membrane with characteristics of adult stem cells. These 'niche cells' support limbal epithelial stem cell viability. In culture by themselves, the niche cells display a phenotype typical of mesenchymal stem cells. These stromal stem cells exhibit a potential to differentiate to multiple cell types, including keratocytes, thus providing an abundant source of these rare cells for experimental and bioengineering applications. Stromal stem cells have also shown the ability to remodel pathological stromal tissue, suppressing inflammation and restoring transparency. Because stromal stem cells can be obtained by biopsy, they offer a potential for autologous stem cell treatment for stromal opacities. This review provides an overview of the status of work on this interesting cell population. PMID:26804252

  16. The prognostic role of desmoplastic stroma in pancreatic ductal adenocarcinoma

    PubMed Central

    Soonawalla, Zahir; Liu, Stanley; O'Neill, Eric; Mukherjee, Somnath; McKenna, W. Gillies; Muschel, Ruth; Fokas, Emmanouil

    2016-01-01

    Pancreatic ductal adenocarcinoma (PDAC) is characterized by an abundant desmoplastic stroma. We examined the prognostic value of stroma density and activity in patients with resectable PDAC treated with surgery and adjuvant gemcitabine-based chemotherapy. FFPE-tissue from the pancreatectomy of 145 patients was immunohistochemically stained for haematoxylin-eosin and Masson's trichrome to assess stroma density, and alpha-smooth muscle actin (αSMA) expression for activated pancreatic stellate cells. Their expression was correlated with clinicopathological characteristics as well as overall survival (OS), progression-free survival (PFS), local progression-free survival (LPFS) and distant metastases free-survival (DMFS). After a mean follow-up of 20 months (range, 2–69 months), the median OS was 21 months and the 3-year OS was 35.7%. In multivariate analysis, highly-dense stroma was an independent prognostic parameter for OS (p = 0.001), PFS (p = 0.007), LPFS (p = 0.001) and DMFS (p = 0.002), while αSMA expression lacked significance. Interestingly, highly-dense stroma retained significance for the four clinical endpoints only in early (pT1–2) but not late (pT3–4) stage tumors. Additionally, late pT-stage (pT3–4), the presence of lymph node metastases (pN+ vs pN0), perineural/neural invasion and administration of adjuvant chemotherapy also correlated with prognosis in multivariate analysis. Altogether, stroma density constitutes an independent prognostic marker in PDAC patients treated with adjuvant chemotherapy. Our findings highlight the dynamic complexity of desmoplasia and indicate that highly-dense stroma is correlated with better outcome. Further validation of the prognostic value of stroma as a biomarker and its role in PDAC patients after adjuvant chemotherapy is warranted and will be performed in a prospective study. PMID:26716653

  17. The autophagic tumor stroma model of cancer

    PubMed Central

    Pavlides, Stephanos; Tsirigos, Aristotelis; Migneco, Gemma; Whitaker-Menezes, Diana; Chiavarina, Barbara; Flomenberg, Neal; Frank, Philippe G; Casimiro, Mathew C; Wang, Chenguang; Pestell, Richard G; Martinez-Outschoorn, Ubaldo E; Howell, Anthony

    2010-01-01

    A loss of stromal caveolin-1 (Cav-1) in the tumor fibroblast compartment is associated with early tumor recurrence, lymphnode metastasis and tamoxifen-resistance, resulting in poor clinical outcome in breast cancer patients. Here, we have used Cav-1 (−/−) null mice as a pre-clinical model for this “lethal tumor micro-environment”. Metabolic profiling of Cav-1 (−/−) mammary fat pads revealed the upregulation of numerous metabolites (nearly 100), indicative of a major catabolic phenotype. Our results are consistent with the induction of oxidative stress, mitochondrial dysfunction and autophagy/mitophagy. The two most prominent metabolites that emerged from this analysis were ADMA (asymmetric dimethyl arginine) and BHB (beta-hydroxybutyrate; a ketone body), which are markers of oxidative stress and mitochondrial dysfunction, respectively. Transcriptional profiling of Cav-1 (−/−) stromal cells and human tumor stroma from breast cancer patients directly supported an association with oxidative stress, mitochondrial dysfunction and autophagy/mitophagy, as well as ADMA and ketone production. MicroRNA profiling of Cav-1 (−/−) stromal cells revealed the upregulation of two key cancer-related miR's, namely miR-31 and miR-34c. Consistent with our metabolic findings, these miR's are associated with oxidative stress (miR-34c) or activation of the hypoxic response/HIF1α (miR-31), which is sufficient to drive authophagy/mitophagy. Thus, via an unbiased comprehensive analysis of a lethal tumor micro-environment, we have identified a number of candidate biomarkers (ADMA, ketones and miR-31/34c) that could be used to identify high-risk cancer patients at diagnosis, for treatment stratification and/or for evaluating therapeutic efficacy during anti-cancer therapy. We propose that the levels of these key biomarkers (ADMA, ketones/BHB, miR-31 and miR-34c) could be (1) assayed using serum or plasma from cancer patients or (2) performed directly on excised tumor

  18. Targeting the tumor stroma in hepatocellular carcinoma

    PubMed Central

    Heindryckx, Femke; Gerwins, Pär

    2015-01-01

    Hepatocellular carcinoma (HCC) is one of the most common and deadly cancers worldwide. In ninety percent of the cases it develops as a result of chronic liver damage and it is thus a typical inflammation-related cancer characterized by the close relation between the tumor microenvironment and tumor cells. The stromal environment consists out of several cell types, including hepatic stellate cells, macrophages and endothelial cells. They are not just active bystanders in the pathogenesis of HCC, but play an important and active role in tumor initiation, progression and metastasis. Furthermore, the tumor itself influences these cells to create a background that is beneficial for sustaining tumor growth. One of the key players is the hepatic stellate cell, which is activated during liver damage and differentiates towards a myofibroblast-like cell. Activated stellate cells are responsible for the deposition of extracellular matrix, increase the production of angiogenic factors and stimulate the recruitment of macrophages. The increase of angiogenic factors (which are secreted by macrophages, tumor cells and activated stellate cells) will induce the formation of new blood vessels, thereby supplying the tumor with more oxygen and nutrients, thus supporting tumor growth and offering a passageway in the circulatory system. In addition, the secretion of chemokines by the tumor cells leads to the recruitment of tumor associated macrophages. These tumor associated macrophages are key actors of cancer-related inflammation, being the main type of inflammatory cells infiltrating the tumor environment and exerting a tumor promoting effect by secreting growth factors, stimulating angiogenesis and influencing the activation of stellate cells. This complex interplay between the several cell types involved in liver cancer emphasizes the need for targeting the tumor stroma in HCC patients. PMID:25729472

  19. Imaging aspects of the tumor stroma with therapeutic implications.

    PubMed

    Narunsky, Lian; Oren, Roni; Bochner, Filip; Neeman, Michal

    2014-02-01

    Cancer cells rely on extensive support from the stroma in order to survive, proliferate and invade. The tumor stroma is thus an important potential target for anti-cancer therapy. Typical changes in the stroma include a shift from the quiescence promoting-antiangiogenic extracellular matrix to a provisional matrix that promotes invasion and angiogenesis. These changes in the extracellular matrix are induced by changes in the secretion of extracellular matrix proteins and glucose amino glycans, extravasation of plasma proteins from hyperpermeable vessels and release of matrix modifying enzymes resulting in cleavage and cross-linking of matrix macromolecules. These in turn alter the rigidity of the matrix and the exposure and release of cytokines. Changes in matrix rigidity and vessel permeability affect drug delivery and mediate resistance to cytotoxic therapy. These stroma changes are brought about not only by the cancer cells, but also through the action of many cell types that are recruited by tumors including immune cells, fibroblasts and endothelial cells. Within the tumor, these normal host cells are activated resulting in loss of inhibitory and induction of cancer promoting activities. Key to the development of stroma-targeted therapies, selective biomarkers were developed for specific imaging of key aspects of the tumor stroma. PMID:24134903

  20. Imaging aspects of the tumor stroma with therapeutic implications

    PubMed Central

    Narunsky, Lian; Oren, Roni; Bochner, Filip; Neeman, Michal

    2013-01-01

    Cancer cells rely on extensive support from the stroma in order to survive, proliferate and invade. The tumor stroma is thus an important potential target for anti-cancer therapy. Typical changes in the stroma include a shift from the quiescence promoting- antiangiogenic extracellular matrix to a provisional matrix that promotes invasion and angiogenesis. These changes in the extracellular matrix are induced by changes in the secretion of extracellular matrix proteins and glucose amino glycans, extravasation of plasma proteins from hyperpermeable vessels and release of matrix modifying enzymes resulting in cleavage and crosslinking of matrix macromolecules. These in turn alter the rigidity of the matrix and the exposure and release of cytokines. Changes in matrix rigidity and vessel permeability affect drug delivery and mediate resistance to cytotoxic therapy. These stroma changes are brought about not only by the cancer cells, but also through the action of many cell types that are recruited by tumors including immune cells, fibroblasts and endothelial cells. Within the tumor, these normal host cells are activated resulting in loss of inhibitory and induction of cancer promoting activities. Key to the development of stroma targeted therapies, selective biomarkers were developed for specific imaging of key aspects of the tumor stroma. PMID:24134903

  1. Diagnosis of Prostate Cancer Using Differentially Expressed Genes in Stroma

    PubMed Central

    Jia, Zhenyu; Wang, Yipeng; Sawyers, Anne; Yao, Huazhen; Rahmatpanah, Farahnaz; Xia, Xiao-Qin; Xu, Qiang; Pio, Rebecca; Turan, Tolga; Koziol, James A.; Goodison, Steve; Carpenter, Philip; Wang-Rodriquez, Jessica; Simoneau, Anne; Meyskens, Frank; Sutton, Manuel; Lernhardt, Waldemar; Beach, Thomas; Monforte, Joseph; McClelland, Michael; Mercola, Dan

    2011-01-01

    Over one million prostate biopsies are performed in the U.S. every year. A failure to find cancer is not definitive in a significant percentage of patients due to the presence of equivocal structures or continuing clinical suspicion. We have identified gene expression changes in stroma that can detect tumor nearby. We compared gene expression profiles of 13 biopsies containing stroma near tumor and 15 biopsies from volunteers without prostate cancer. About 3800 significant expression changes were found and thereafter filtered using independent expression profiles to eliminate possible age-related genes and genes expressed at detectable levels in tumor cells. A stroma-specific classifier for nearby tumor was constructed based on 114 candidate genes and tested on 364 independent samples, including 243 tumor-bearing samples and 121 non-tumor samples (normal biopsies, normal autopsies, remote stroma, as well as stroma within a few millimeters of tumor). The classifier predicted the tumor status of patients using tumor-free samples with an average accuracy of 97% (sensitivity = 98% and specificity = 88%) whereas classifiers trained with sets of 100 randomly generated genes had no diagnostic value. These results indicate that the prostate cancer microenvironment exhibits reproducible changes useful for categorizing the presence of tumor in patients when a prostate sample is derived from near the tumor but does not contain any recognizable tumor. PMID:21459804

  2. Apparent-Dip Methods.

    ERIC Educational Resources Information Center

    Travis, R. B.; Lamar, D. L.

    1987-01-01

    Reviews methods of determining apparent dip and highlights the use of a device which consists of a nomogram printed on a protractor. Explains how the apparent-dip calculator-protractor can be constructed and outlines the steps for its operation. (ML)

  3. Tumor Stroma, Tumor Blood Vessels, and Antiangiogenesis Therapy.

    PubMed

    Dvorak, Harold F

    2015-01-01

    Solid tumors generally require a vascularized connective tissue stroma if they are to grow beyond minimal size. They generate that stroma in part by secreting vascular endothelial growth factor (VEGF), a potent vascular permeability and angiogenic factor. Increased vascular permeability leads to deposition of a provisional fibrin stroma, which supports tumor, connective tissue, and inflammatory cell migration and plays an active role in the formation of mature vascularized stroma. Vascular endothelial growth factor-induced tumor blood vessels are heterogeneous, of at least 6 distinct types, and develop linearly over time. They include both angiogenic (mother vessels, glomeruloid microvascular proliferations, vascular malformations, capillaries) and arteriovenogenic (feeding arteries, draining veins) blood vessels. Attacking the tumor vasculature with drugs that target VEGF or its receptors (VEGFR) has come into vogue but has been less effective than had been hope for. One reason for this is that anti-VEGF/VEGFR therapy attacks only a subset of tumor blood vessels, the earliest to form. New targets on late-forming blood vessels such as feeding arteries would be useful in helping antivascular cancer therapy fulfill its promise. PMID:26222073

  4. Transcriptome analysis of individual stromal cell populations identifies stroma-tumor crosstalk in mouse lung cancer model.

    PubMed

    Choi, Hyejin; Sheng, Jianting; Gao, Dingcheng; Li, Fuhai; Durrans, Anna; Ryu, Seongho; Lee, Sharrell B; Narula, Navneet; Rafii, Shahin; Elemento, Olivier; Altorki, Nasser K; Wong, Stephen T C; Mittal, Vivek

    2015-02-24

    Emerging studies have begun to demonstrate that reprogrammed stromal cells play pivotal roles in tumor growth, metastasis, and resistance to therapy. However, the contribution of stromal cells to non-small-cell lung cancer (NSCLC) has remained underexplored. We used an orthotopic model of Kras-driven NSCLC to systematically dissect the contribution of specific hematopoietic stromal cells in lung cancer. RNA deep-sequencing analysis of individually sorted myeloid lineage and tumor epithelial cells revealed cell-type-specific differentially regulated genes, indicative of activated stroma. We developed a computational model for crosstalk signaling discovery based on ligand-receptor interactions and downstream signaling networks and identified known and novel tumor-stroma paracrine and tumor autocrine crosstalk-signaling pathways in NSCLC. We provide cellular and molecular insights into components of the lung cancer microenvironment that contribute to carcinogenesis. This study has the potential for development of therapeutic strategies that target tumor-stroma interactions and may complement conventional anti-cancer treatments. PMID:25704820

  5. Cancer-stroma evolutionary dynamics in stress-gradient microenvironment

    NASA Astrophysics Data System (ADS)

    Wu, Amy; Lambert, Guillaume; Austin, Robert; Sturm, James; Khin, Zayar; Silva, Ariosto

    2012-02-01

    In order to study the evolution of drug resistance in cancer, it is important to mimic the tumor microenvironment, in which cells are exposed to not uniform concentrations but rather gradients of drugs, nutrients, and other factors Compared to traditional in-vitro methods, microfluidic structure enables better control of the temporal and spatial profile of gradients. Here we demonstrate a microfluidic Doxorubicin gradient environment with heterogeneous landscape, and culture multiple myeloma (8226-S, expressing RFP) and bone marrow stroma (HS-5, expressing GFP) cell lines together. The myeloma cells are not directly motile, but they are able to migrate via the adhesion to motile stroma cells. The indirect motility mechanism of the myeloma cells is crucial for the adaptation to stress environment. Finally, we will report the co-culture dynamics under the stress of doxorubicin gradients, observing for cellular migrations and growth

  6. Riboflavin concentration in corneal stroma after intracameral injection

    PubMed Central

    Li, Na; Peng, Xiu-Jun; Fan, Zheng-Jun; Pang, Xu; Xia, Yu; Wu, Teng-Fei

    2015-01-01

    AIM To evaluate the enrichment of riboflavin in the corneal stroma after intracameral injection to research the barrier ability of the corneal endothelium to riboflavin in vivo. METHODS The right eyes of 30 New Zealand white rabbits were divided into three groups. Different concentrations riboflavin-balanced salt solutions (BSS) were injected into the anterior chamber (10 with 0.5%, 10 with 1%, and 10 with 2%). Eight corneal buttons of 8.5 mm in diameter from each group were dissected at 30min after injection and the riboflavin concentrations in the corneal stroma were determined using high-performance liquid chromatography (HPLC) after removing the epithelium and endothelium. The other two rabbits in every group were observed for 24h and sacrificed. As a comparison, the riboflavin concentrations from 16 corneal stromal samples were determined using HPLC after instillation of 0.1% riboflavin-BSS solution for 30min on the corneal surface (8 without epithelium and 8 with intact epithelium). RESULTS The mean riboflavin concentrations were 11.19, 18.97, 25.08, 20.18, and 1.13 µg/g for 0.5%, 1%, 2%, de-epithelialzed samples, and the transepithelial groups, respectively. The color change of the corneal stroma and the HPLC results showed that enrichment with riboflavin similar to classical de-epithelialized corneal collagen crosslinking (CXL) could be achieved by intracameral 1% riboflavin-BSS solution after 30min; the effect appeared to be continuous for at least 30min. CONCLUSION Riboflavin can effectively penetrate the corneal stroma through the endothelium after an intracameral injection in vivo, so it could be an enhancing method that could improve the corneal riboflavin concentration in transepithelial CXL. PMID:26085993

  7. Tumour stroma-derived lipocalin-2 promotes breast cancer metastasis.

    PubMed

    Ören, Bilge; Urosevic, Jelena; Mertens, Christina; Mora, Javier; Guiu, Marc; Gomis, Roger R; Weigert, Andreas; Schmid, Tobias; Grein, Stephan; Brüne, Bernhard; Jung, Michaela

    2016-07-01

    Tumour cell-secreted factors skew infiltrating immune cells towards a tumour-supporting phenotype, expressing pro-tumourigenic mediators. However, the influence of lipocalin-2 (Lcn2) on the metastatic cascade in the tumour micro-environment is still not clearly defined. Here, we explored the role of stroma-derived, especially macrophage-released, Lcn2 in breast cancer progression. Knockdown studies and neutralizing antibody approaches showed that Lcn2 contributes to the early events of metastasis in vitro. The release of Lcn2 from macrophages induced an epithelial-mesenchymal transition programme in MCF-7 breast cancer cells and enhanced local migration as well as invasion into the extracellular matrix, using a three-dimensioanl (3D) spheroid model. Moreover, a global Lcn2 deficiency attenuated breast cancer metastasis in both the MMTV-PyMT breast cancer model and a xenograft model inoculating MCF-7 cells pretreated with supernatants from wild-type and Lcn2-knockdown macrophages. To dissect the role of stroma-derived Lcn2, we employed an orthotopic mammary tumour mouse model. Implantation of wild-type PyMT tumour cells into Lcn2-deficient mice left primary mammary tumour formation unaltered, but specifically reduced tumour cell dissemination into the lung. We conclude that stroma-secreted Lcn2 promotes metastasis in vitro and in vivo, thereby contributing to tumour progression. Our study highlights the tumourigenic potential of stroma-released Lcn2 and suggests Lcn2 as a putative therapeutic target. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. PMID:27038000

  8. Pancreatic cancer and its stroma: A conspiracy theory

    PubMed Central

    Xu, Zhihong; Pothula, Srinivasa P; Wilson, Jeremy S; Apte, Minoti V

    2014-01-01

    Pancreatic cancer is characterised by a prominent desmoplastic/stromal reaction that has received little attention until recent times. Given that treatments focusing on pancreatic cancer cells alone have failed to significantly improve patient outcome over many decades, research efforts have now moved to understanding the pathophysiology of the stromal reaction and its role in cancer progression. In this regard, our Group was the first to identify the cells (pancreatic stellate cells, PSCs) that produced the collagenous stroma of pancreatic cancer and to demonstrate that these cells interacted closely with cancer cells to facilitate local tumour growth and distant metastasis. Evidence is accumulating to indicate that stromal PSCs may also mediate angiogenesis, immune evasion and the well known resistance of pancreatic cancer to chemotherapy and radiotherapy. This review will summarise current knowledge regarding the critical role of pancreatic stellate cells and the stroma in pancreatic cancer biology and the therapeutic approaches being developed to target the stroma in a bid to improve the outcome of this devastating disease. PMID:25170206

  9. Pancreatic cancer and its stroma: a conspiracy theory.

    PubMed

    Xu, Zhihong; Pothula, Srinivasa P; Wilson, Jeremy S; Apte, Minoti V

    2014-08-28

    Pancreatic cancer is characterised by a prominent desmoplastic/stromal reaction that has received little attention until recent times. Given that treatments focusing on pancreatic cancer cells alone have failed to significantly improve patient outcome over many decades, research efforts have now moved to understanding the pathophysiology of the stromal reaction and its role in cancer progression. In this regard, our Group was the first to identify the cells (pancreatic stellate cells, PSCs) that produced the collagenous stroma of pancreatic cancer and to demonstrate that these cells interacted closely with cancer cells to facilitate local tumour growth and distant metastasis. Evidence is accumulating to indicate that stromal PSCs may also mediate angiogenesis, immune evasion and the well known resistance of pancreatic cancer to chemotherapy and radiotherapy. This review will summarise current knowledge regarding the critical role of pancreatic stellate cells and the stroma in pancreatic cancer biology and the therapeutic approaches being developed to target the stroma in a bid to improve the outcome of this devastating disease. PMID:25170206

  10. Earthquake Apparent Stress Scaling

    NASA Astrophysics Data System (ADS)

    Walter, W. R.; Mayeda, K.; Ruppert, S.

    2002-12-01

    There is currently a disagreement within the geophysical community on the way earthquake energy scales with magnitude. One set of recent papers finds evidence that energy release per seismic moment (apparent stress) is constant (e.g. Choy and Boatwright, 1995; McGarr, 1999; Ide and Beroza, 2001). Another set of recent papers finds the apparent stress increases with magnitude (e.g. Kanamori et al., 1993 Abercrombie, 1995; Mayeda and Walter, 1996; Izutani and Kanamori, 2001). The resolution of this issue is complicated by the difficulty of accurately accounting for and determining the seismic energy radiated by earthquakes over a wide range of event sizes in a consistent manner. We have just started a project to reexamine this issue by analyzing aftershock sequences in the Western U.S. and Turkey using two different techniques. First we examine the observed regional S-wave spectra by fitting with a parametric model (Walter and Taylor, 2002) with and without variable stress drop scaling. Because the aftershock sequences have common stations and paths we can examine the S-wave spectra of events by size to determine what type of apparent stress scaling, if any, is most consistent with the data. Second we use regional coda envelope techniques (e.g. Mayeda and Walter, 1996; Mayeda et al, 2002) on the same events to directly measure energy and moment. The coda techniques corrects for path and site effects using an empirical Green function technique and independent calibration with surface wave derived moments. Our hope is that by carefully analyzing a very large number of events in a consistent manner using two different techniques we can start to resolve this apparent stress scaling issue. This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under Contract No. W-7405-Eng-48.

  11. Apparent arterial compliance.

    PubMed

    Quick, C M; Berger, D S; Noordergraaf, A

    1998-04-01

    Recently, there has been renewed interest in estimating total arterial compliance. Because it cannot be measured directly, a lumped model is usually applied to derive compliance from aortic pressure and flow. The archetypical model, the classical two-element windkessel, assumes 1) system linearity and 2) infinite pulse wave velocity. To generalize this model, investigators have added more elements and have incorporated nonlinearities. A different approach is taken here. It is assumed that the arterial system 1) is linear and 2) has finite pulse wave velocity. In doing so, the windkessel is generalized by describing compliance as a complex function of frequency that relates input pressure to volume stored. By applying transmission theory, this relationship is shown to be a function of heart rate, peripheral resistance, and pulse wave reflection. Because this pressure-volume relationship is generally not equal to total arterial compliance, it is termed "apparent compliance." This new concept forms the natural counterpart to the established concept of apparent pulse wave velocity. PMID:9575945

  12. Stroma Cells in Tumor Microenvironment and Breast Cancer

    PubMed Central

    Mao, Yan; Keller, Evan T.; Garfield, David H.; Shen, Kunwei; Wang, Jianhua

    2015-01-01

    Cancer is a systemic disease, encompassing multiple components of both tumor cells themselves and host stromal cells. It is now clear that stromal cells in the tumor microenvironment play an important role in cancer development. Molecular events through which reactive stromal cells affect cancer cells can be defined so that biomarkers and therapeutic targets can be identified. Cancer-associated fibroblasts (CAFs) make up the bulk of cancer stroma and affect the tumor microenvironment such that they promote cancer initiation, angiogenesis, invasion and metastasis. In breast cancer, CAFs not only promote tumor progression, but also induce therapeutic resistances. Accordingly, targeting CAFs provides a novel way to control tumors with therapeutic resistances. This review summarizes the current understanding of tumor stroma in breast cancer with a particular emphasis on the role of CAFs and the therapeutic implications of CAFs. The effects of other stromal components such as endothelial cells, macrophages and adipocytes in breast cancer are also discussed. Finally, we describe the biologic markers to sort patients into a specific and confirmed subtype for personalized treatment. PMID:23114846

  13. The apparent Universe

    NASA Astrophysics Data System (ADS)

    Binétruy, P.; Helou, A.

    2015-10-01

    We exploit the parallel between dynamical black holes and cosmological spacetimes to describe the evolution of Friedmann-Lemaître-Robertson-Walker universes from the point of view of an observer in terms of the dynamics of the apparent horizon. Using the Hayward-Kodama formalism of dynamical black holes, we clarify the role of the Clausius relation to derive the Friedmann equations for a Universe, in the spirit of Jacobson’s work on the thermodynamics of spacetime. We also show how dynamics at the horizon naturally leads to the quantum-mechanical process of Hawking radiation. We comment on the connection of this work with recent ideas to consider our observable Universe as a Bose-Einstein condensate and on the corresponding role of vacuum energy.

  14. Boosted apparent horizons

    NASA Astrophysics Data System (ADS)

    Akcay, Sarp

    Boosted black holes play an important role in General Relativity (GR), especially in relation to the binary black hole problem. Solving Einstein vac- uum equations in the strong field regime had long been the holy grail of numerical relativity until the significant breakthroughs made in 2005 and 2006. Numerical relativity plays a crucial role in gravitational wave detection by providing numerically generated gravitational waveforms that help search for actual signatures of gravitational radiation exciting laser interferometric de- tectors such as LIGO, VIRGO and GEO600 here on Earth. Binary black holes orbit each other in an ever tightening adiabatic inspiral caused by energy loss due to gravitational radiation emission. As the orbits shrinks, the holes speed up and eventually move at relativistic speeds in the vicinity of each other (separated by ~ 10M or so where 2M is the Schwarzschild radius). As such, one must abandon the Newtonian notion of a point mass on a circular orbit with tangential velocity and replace it with the concept of black holes, cloaked behind spheroidal event horizons that become distorted due to strong gravity, and further appear distorted because of Lorentz effects from the high orbital velocity. Apparent horizons (AHs) are 2-dimensional boundaries that are trapped surfaces. Conceptually, one can think of them as 'quasi-local' definitions for a black hole horizon. This will be explained in more detail in chapter 2. Apparent horizons are especially important in numerical relativity as they provide a computationally efficient way of describing and locating a black hole horizon. For a stationary spacetime, apparent horizons are 2-dimensional cross-sections of the event horizon, which is itself a 3-dimensional null surface in spacetime. Because an AH is a 2-dimensional cross-section of an event horizon, its area remains invariant under distortions due to Lorentz boosts although its shape changes. This fascinating property of the AH can be

  15. Apparent capitellar fractures.

    PubMed

    Ring, David

    2007-11-01

    Isolated capitellar fractures are rare but are identified as such, even when they are more complex, because the displaced capitellar fracture is usually the most obvious and identifiable radiographic finding and because teaching has traditionally underemphasized the involvement of the trochlea in such fractures. The author prefers the term 'apparent capitellar fractures' and draws on his experience to explain why he favors three-dimensional CT for depicting fracture detail. This article discusses treatment options, emphasizing open reduction and internal fixation to restore the native elbow. Operative techniques, including extensile lateral exposure and olecranon osteotomy; fixation techniques; and elbow arthroplasty, are described. Complications, such as ulnar neuropathy and infection, are also covered. PMID:18054674

  16. Earthquake Apparent Stress Scaling

    NASA Astrophysics Data System (ADS)

    Mayeda, K.; Walter, W. R.

    2003-04-01

    There is currently a disagreement within the geophysical community on the way earthquake energy scales with magnitude. One set of recent papers finds evidence that energy release per seismic moment (apparent stress) is constant (e.g. Choy and Boatwright, 1995; McGarr, 1999; Ide and Beroza, 2001). Another set of recent papers finds the apparent stress increases with magnitude (e.g. Kanamori et al., 1993 Abercrombie, 1995; Mayeda and Walter, 1996; Izutani and Kanamori, 2001). The resolution of this issue is complicated by the difficulty of accurately accounting for and determining the seismic energy radiated by earthquakes over a wide range of event sizes in a consistent manner. We have just started a project to reexamine this issue by applying the same methodology to a series of datasets that spans roughly 10 orders in seismic moment, M0. We will summarize recent results using a coda envelope methodology of Mayeda et al, (2003) which provide the most stable source spectral estimates to date. This methodology eliminates the complicating effects of lateral path heterogeneity, source radiation pattern, directivity, and site response (e.g., amplification, f-max and kappa). We find that in tectonically active continental crustal areas the total radiated energy scales as M00.25 whereas in regions of relatively younger oceanic crust, the stress drop is generally lower and exhibits a 1-to-1 scaling with moment. In addition to answering a fundamental question in earthquake source dynamics, this study addresses how one would scale small earthquakes in a particular region up to a future, more damaging earthquake. This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under Contract No. W-7405-Eng-48.

  17. Prognostic Significance of the Tumor-Stroma Ratio in Epithelial Ovarian Cancer

    PubMed Central

    Chen, Ying; Zhang, Lei; Liu, Wenxin; Liu, Xiangyu

    2015-01-01

    Tumor-stroma ratio (TSR) has recently been identified as a promising prognostic parameter for several solid tumors. This study aimed to evaluate the prognostic role of TSR in epithelial ovarian cancer (EOC) and 838 EOC patients were enrolled in this study. TSR was estimated on hematoxylin-and-eosin-stained tissue sections from the most invasive part of the primary tumor. Patients were classified as stroma-rich or stroma-poor according to the proportion of stroma ≥50% or <50%. Chi-square test analysis revealed that TSR were significantly associated with FIGO stage, LN status, and recurrence or not (all of them P < 0.001). The higher stroma-rich proportions were found in EOC patients with advanced stage (36.13% versus 19.75%), LN metastasis (51.93% versus 27.25%), and recurrence (34.27% versus 6.82%). Stroma-rich EOC patients had obvious shorter median time of progression-free survival (29 versus 39 months) and overall survival (50 versus 58 months), respectively. TSR was an independent prognostic factor for the evaluation of PFS in EOC. Stroma-rich tumors had worse prognosis and higher risk of relapse compared with those in stroma-poor tumors in EOC patients. Considered easy to determine for routine pathological examination, TSR may serve as a new prognostic histological parameter in EOC. PMID:26609529

  18. IL-33 activates tumor stroma to promote intestinal polyposis.

    PubMed

    Maywald, Rebecca L; Doerner, Stephanie K; Pastorelli, Luca; De Salvo, Carlo; Benton, Susan M; Dawson, Emily P; Lanza, Denise G; Berger, Nathan A; Markowitz, Sanford D; Lenz, Heinz-Josef; Nadeau, Joseph H; Pizarro, Theresa T; Heaney, Jason D

    2015-05-12

    Tumor epithelial cells develop within a microenvironment consisting of extracellular matrix, growth factors, and cytokines produced by nonepithelial stromal cells. In response to paracrine signals from tumor epithelia, stromal cells modify the microenvironment to promote tumor growth and metastasis. Here, we identify interleukin 33 (IL-33) as a regulator of tumor stromal cell activation and mediator of intestinal polyposis. In human colorectal cancer, IL-33 expression was induced in the tumor epithelium of adenomas and carcinomas, and expression of the IL-33 receptor, IL1RL1 (also referred to as IL1-R4 or ST2), localized predominantly to the stroma of adenoma and both the stroma and epithelium of carcinoma. Genetic and antibody abrogation of responsiveness to IL-33 in the Apc(Min/+) mouse model of intestinal tumorigenesis inhibited proliferation, induced apoptosis, and suppressed angiogenesis in adenomatous polyps, which reduced both tumor number and size. Similar to human adenomas, IL-33 expression localized to tumor epithelial cells and expression of IL1RL1 associated with two stromal cell types, subepithelial myofibroblasts and mast cells, in Apc(Min/+) polyps. In vitro, IL-33 stimulation of human subepithelial myofibroblasts induced the expression of extracellular matrix components and growth factors associated with intestinal tumor progression. IL-33 deficiency reduced mast cell accumulation in Apc(Min/+) polyps and suppressed the expression of mast cell-derived proteases and cytokines known to promote polyposis. Based on these findings, we propose that IL-33 derived from the tumor epithelium promotes polyposis through the coordinated activation of stromal cells and the formation of a protumorigenic microenvironment. PMID:25918379

  19. IL-33 activates tumor stroma to promote intestinal polyposis

    PubMed Central

    Maywald, Rebecca L.; Doerner, Stephanie K.; Pastorelli, Luca; De Salvo, Carlo; Benton, Susan M.; Dawson, Emily P.; Lanza, Denise G.; Berger, Nathan A.; Markowitz, Sanford D.; Lenz, Heinz-Josef; Nadeau, Joseph H.; Pizarro, Theresa T.; Heaney, Jason D.

    2015-01-01

    Tumor epithelial cells develop within a microenvironment consisting of extracellular matrix, growth factors, and cytokines produced by nonepithelial stromal cells. In response to paracrine signals from tumor epithelia, stromal cells modify the microenvironment to promote tumor growth and metastasis. Here, we identify interleukin 33 (IL-33) as a regulator of tumor stromal cell activation and mediator of intestinal polyposis. In human colorectal cancer, IL-33 expression was induced in the tumor epithelium of adenomas and carcinomas, and expression of the IL-33 receptor, IL1RL1 (also referred to as IL1-R4 or ST2), localized predominantly to the stroma of adenoma and both the stroma and epithelium of carcinoma. Genetic and antibody abrogation of responsiveness to IL-33 in the ApcMin/+ mouse model of intestinal tumorigenesis inhibited proliferation, induced apoptosis, and suppressed angiogenesis in adenomatous polyps, which reduced both tumor number and size. Similar to human adenomas, IL-33 expression localized to tumor epithelial cells and expression of IL1RL1 associated with two stromal cell types, subepithelial myofibroblasts and mast cells, in ApcMin/+ polyps. In vitro, IL-33 stimulation of human subepithelial myofibroblasts induced the expression of extracellular matrix components and growth factors associated with intestinal tumor progression. IL-33 deficiency reduced mast cell accumulation in ApcMin/+ polyps and suppressed the expression of mast cell-derived proteases and cytokines known to promote polyposis. Based on these findings, we propose that IL-33 derived from the tumor epithelium promotes polyposis through the coordinated activation of stromal cells and the formation of a protumorigenic microenvironment. PMID:25918379

  20. CCX-CKR deficiency alters thymic stroma impairing thymocyte development and promoting autoimmunity.

    PubMed

    Bunting, Mark D; Comerford, Iain; Seach, Natalie; Hammett, Maree V; Asquith, Darren L; Körner, Heinrich; Boyd, Richard L; Nibbs, Robert J B; McColl, Shaun R

    2013-01-01

    The atypical chemokine receptor CCX-CKR regulates bioavailability of CCL19, CCL21, and CCL25, homeostatic chemokines that play crucial roles in thymic lymphopoiesis. Deletion of CCX-CKR results in accelerated experimental autoimmunity induced by immunization. Here we show that CCX-CKR deletion also increases incidence of a spontaneous Sjögren's syndrome-like pathology, characterized by lymphocytic infiltrates in salivary glands and liver of CCX-CKR(-/-) mice, suggestive of a defect in self-tolerance when CCX-CKR is deleted. This prompted detailed examination of the thymus in CCX-CKR(-/-) mice. Negatively selected mature SP cells were less abundant in CCX-CKR(-/-) thymi, yet expansion of both DP and immature SP cells was apparent. Deletion of CCX-CKR also profoundly reduced proportions of DN3 thymocyte precursors and caused DN2 cells to accumulate within the medulla. These effects are likely driven by alterations in thymic stroma as CCX-CKR(-/-) mice have fewer cTECs per thymocyte, and cTECs express the highest level of CCX-CKR in the thymus. A profound decrease in CCL25 within the thymic cortex was observed in CCX-CKR(-/-) thymi, likely accounting for their defects in thymocyte distribution and frequency. These findings identify a novel role for CCX-CKR in regulating cTEC biology, which promotes optimal thymocyte development and selection important for self-tolerant adaptive immunity. PMID:23152546

  1. The bone marrow stroma in hematological neoplasms—a guilty bystander

    PubMed Central

    Tripodo, Claudio; Sangaletti, Sabina; Piccaluga, Pier P.; Prakash, Sonam; Franco, Giovanni; Borrello, Ivan; Orazi, Attilio; Colombo, Mario P.; Pileri, Stefano A.

    2013-01-01

    In the setting of hematological neoplasms, changes in the bone marrow (BM) stroma might arise from pressure exerted by the neoplastic clone in shaping a supportive microenvironment, or from chronic perturbation of the BM homeostasis. Under such conditions, alterations in the composition of the BM stroma can be profound, and could emerge as relevant prognostic factors. In this Review, we delineate the multifaceted contribution of the BM stroma to the pathobiology of several hematological neoplasms, and discuss the impact of stromal modifications on the natural course of these diseases. Specifically, we highlight the involvement of BM stromal components in lymphoid and myeloid malignancies, and present the most relevant processes responsible for remodeling the BM stroma. The role of bystander BM stromal elements in the setting of hematological neoplasms is discussed, strengthening the rationale for treatment strategies that target the BM stroma. PMID:21448151

  2. Hyalinizing Spitz nevus: spindle and epithelioid cell nevus with paucicellular collagenous stroma.

    PubMed

    Liu, Jing; Cohen, Philip R; Farhood, Anwar

    2004-01-01

    Hyalinizing spindle and epithelioid cell nevus (Spitz nevus) is an uncommon melanocytic lesion. The histologic features of this benign tumor can mimic those of certain benign (dermatofibroma and desmoplastic cellular blue nevus) and malignant (metastatic carcinoma and malignant melanoma) neoplasms. We report a woman with a hyalinizing Spitz nevus and review the clinical characteristics, histologic features, and differential diagnosis of this lesion. The lesion presented as an asymptomatic red firm nodule on her abdomen. Microscopic examination showed a symmetric lesion in the dermis. The neoplastic cells were large and epithelioid-shaped or plump and spindle-shaped. They were present as isolated individual cells, single cells in a linear pattern, small nests, and fascicles in a paucicellular hyalinized stroma. Neoplastic cells with prominent eosinophilic nucleoli were evenly exhibited from the superficial to deep lesion. Diffuse expression of S-100 protein and absence of staining with antibodies to cytokeratin and HMB-45 were observed. The features were diagnostic of a hyalinizing Spitz nevus. Hyalinizing Spitz nevus is a benign lesion whose histologic features may mimic dermatofibroma, desmoplastic cellular blue nevus, metastatic carcinoma, and malignant melanoma. Immunohistochemical studies are helpful to differentiate these lesions. PMID:14746435

  3. Baculovirus phosphoprotein pp31 is associated with virogenic stroma.

    PubMed Central

    Guarino, L A; Dong, W; Xu, B; Broussard, D R; Davis, R W; Jarvis, D L

    1992-01-01

    The PstI K fragment of Autographa californica nuclear polyhedrosis virus (AcMNPV) encodes a protein with a molecular weight of 31,000. To define the role of this protein (pp31) in virus infection further, it was overexpressed in bacteria and used to produce polyclonal antiserum. Radioimmunoprecipitation analysis indicated that pp31 was synthesized during both the early and late phases of virus infection, consistent with previous analyses indicating that the gene was regulated by tandem early and late promoters. Metabolic labeling of cells with carrier-free phosphate indicated that pp31 was phosphorylated. Biochemical fractionation experiments showed that pp31 was localized in the nucleus and that it was more stably associated with the nucleus at later times of infection. Immunoblot analysis of subnuclear fractions indicated that pp31 was associated predominantly with the chromatin and nuclear matrix fractions. Immunofluorescence experiments confirmed that the pp31 protein was localized in the nucleus. Nuclear staining was relatively uniform early but was more centrally nuclear later in infection. Immunoelectron microscopy indicated that the pp31 protein was a component of virogenic stroma. Southwestern (DNA-protein) blot analysis demonstrated that pp31 is a DNA-binding protein. These findings suggest a possible role for pp31 in the virus life cycle. Images PMID:1433508

  4. [Treatment Strategy for Gastric Carcinoma with Lymphoid Stroma].

    PubMed

    Kobayashi, Ryosuke; Takiguchi, Nobuhiro; Nabeya, Yoshihiro; Ikeda, Atsushi; Souda, Hiroaki; Kainuma, Osamu; Tonooka, Toru; Imanishi, Shunsuke; Arimitsu, Hidehito; Chibana, Tomofumi; Ishige, Fumitaka; Sasaki, Kosuke; Yamamoto, Hiroshi

    2015-11-01

    Gastric carcinoma with lymphoid stroma (GCLS) is a histological type with severe lymphocytic infiltration. GCLS is very rare and few cases have been reported. We examined the clinical features, problems of preoperative diagnosis, and treatment of 14 cases (1.8%) that were diagnosed as GCLS out of 790 gastric cancers surgically resected in our hospital. The mean age was 69 years. Six, 8, and 0 cases were located in the upper, middle, and lower fields of the stomach, respectively, and 8, 1, 4, and 1 cases were macroscopically 0-Ⅱc, 0-Ⅰ, type 2, and type 3, respectively. The depth of invasion was M, SM1, SM2, MP, and SS in 0, 0, 9, 3, and 2 cases, respectively. There were 12 cases(86%)with infection by Epstein-Barr virus, and just 1 case with lymph node metastasis. All cases have had no evidence of recurrence. There were no cases that were diagnosed as GCLS before surgery. GCLS is recognized as having a more favorable prognosis compared with other types of gastric carcinoma, so an aggressive surgery might achieve good outcomes. However, preoperative diagnosis is very difficult and there is a compelling need for new techniques or criteria for diagnosis of GCLS. PMID:26805251

  5. The emerging role of Snail1 in the tumor stroma.

    PubMed

    Herrera, A; Herrera, M; Peña, C

    2016-09-01

    The transcription factor Snail1 leads to the epithelial-mesenchymal transition by repressing the adherent and tight junctions in epithelial cells. This process is related to an increase of cell migratory and mesenchymal properties during both embryonic development and tumor progression. Although Snail1 expression is very limited in adult animals, emerging evidence has placed Snail at the forefront of medical science. As a transcriptional repressor, Snail1 confers cancer stem cell-like traits on tumor cells and promotes drug resistance, tumor recurrence and metastasis. In this review, we summarize recent reports that suggest the pro-tumorigenic roles of Snail1 expression in tumor stroma. The crosstalk between tumor and stromal cells mediated by Snail1 regulates paracrine communication, pro-tumorigenic abilities of cancer cells, extracellular matrix characteristics and mesenchymal differentiation in cancer stem cells and cancer-associated fibroblasts. Therefore, understanding the regulation and functional roles of Snail1 in the tumor microenvironment will provide us with new therapies for treating metastatic disease. PMID:26687368

  6. Expression of proteoglycan core proteins in human bone marrow stroma.

    PubMed Central

    Schofield, K P; Gallagher, J T; David, G

    1999-01-01

    Heparan sulphate proteoglycans (HSPGs) present on the surface of bone marrow stromal cells and in the extracellular matrix (ECM) have important roles in the control of adhesion and growth of haemopoietic stem and progenitor cells. The two main groups of proteoglycans which contain heparan sulphate chains are members of the syndecan and glypican families. In this study we have identified the main surface membrane and matrix-associated HSPGs present in normal human bone marrow stroma formed in long-term culture. Proteoglycans were extracted from the adherent stromal layers and treated with heparitinase and chondroitinase ABC. The core proteins were detected by Western blotting using antibodies directed against syndecans-1-4, glypican-1 and the ECM HSPG, perlecan. Stromal cell expression at the RNA level was detected by Northern blotting and by reverse transcription PCR. Glypican-1, syndecan-3 and syndecan-4 were the major cell-membrane HSPG species and perlecan was the major ECM proteoglycan. There was no evidence for expression of syndecan-1 protein. Syndecan-3 was expressed mainly as a variant or processed 50-55 kDa core protein and in lower amounts as the characteristic 125 kDa core protein. These results suggest that syndecan-3, syndecan-4 and glypican-1 present on the surface of marrow stromal cells, together with perlecan in the ECM, may be responsible for creating the correct stromal 'niche' for the maintenance and development of haemopoietic stem and progenitor cells. The detection of a variant form of syndecan-3 as a major stromal HSPG suggests a specific role for this syndecan in haemopoiesis. PMID:10527946

  7. Key players in pancreatic cancer-stroma interaction: Cancer-associated fibroblasts, endothelial and inflammatory cells

    PubMed Central

    Nielsen, Michael Friberg Bruun; Mortensen, Michael Bau; Detlefsen, Sönke

    2016-01-01

    Pancreatic cancer (PC) is the most aggressive type of common cancers, and in 2014, nearly 40000 patients died from the disease in the United States. Pancreatic ductal adenocarcinoma, which accounts for the majority of PC cases, is characterized by an intense stromal desmoplastic reaction surrounding the cancer cells. Cancer-associated fibroblasts (CAFs) are the main effector cells in the desmoplastic reaction, and pancreatic stellate cells are the most important source of CAFs. However, other important components of the PC stroma are inflammatory cells and endothelial cells. The aim of this review is to describe the complex interplay between PC cells and the cellular and non-cellular components of the tumour stroma. Published data have indicated that the desmoplastic stroma protects PC cells against chemotherapy and radiation therapy and that it might promote the proliferation and migration of PC cells. However, in animal studies, experimental depletion of the desmoplastic stroma and CAFs has led to more aggressive cancers. Hence, the precise role of the tumour stroma in PC remains to be elucidated. However, it is likely that a context-dependent therapeutic modification, rather than pure depletion, of the PC stroma holds potential for the development of new treatment strategies for PC patients. PMID:26973408

  8. Anterior and posterior corneal stroma elasticity after corneal collagen crosslinking treatment

    PubMed Central

    Dias, Janice; Diakonis, Vasilios F.; Kankariya, Vardhaman P.; Yoo, Sonia H.; Ziebarth, Noël M.

    2013-01-01

    The purpose of this project was to assess anterior and posterior corneal stromal elasticity after corneal collagen cross linking (CXL) treatment in human cadaver eyes using Atomic Force Microscopy (AFM) through indentation. Twenty four human cadaver eyes (12 pairs) were included in this study and divided into 2 groups (6 pairs per group). In both groups, the left eye (OS) served as a control (no riboflavin or CXL treatment was performed) and the right eye (OD) underwent CXL treatment (30 minutes of riboflavin pretreatment followed by 30 minutes of exposure to 3mW/cm2 of ultraviolet light). In group 1, the anterior stroma was exposed by manual delamination of approximately 50μm of the corneal stroma including Bowman’s membrane. In group 2, the posterior stroma was exposed by delamination of the anterior 50% of the corneal stroma including Bowman’s membrane. Delamination was performed after crosslinking treatment in the case of the treated eyes. In all eyes, the stromal elasticity was quantified using AFM through indentation. Young’s modulus of elasticity for the anterior cornea (group 1) was 245.9±209.1kPa (range: 82.3 - 530.8 kPa) for the untreated control eyes, and 467.8±373.2kPa (range: 157.4 – 1126 kPa) for the CXL treated eyes. Young’s modulus for the posterior cornea (group 2) was 100.2±61.9kPa (range: 28.1 - 162.6 kPa) for the untreated control eyes and 66.0±31.8kPa (range: 31.3 - 101.7 kPa) for the CXL treated eyes. Young’s modulus of the anterior stroma significantly increased after CXL treatment (p=0.024), whereas the posterior stroma did not demonstrate a significant difference in Young’s modulus after CXL treatment (p=0.170). The anterior stroma was stiffer than the posterior stroma for both the control and CXL treatment groups (p=0.077 and p=0.023, respectively). Our findings demonstrate that stiffness of the anterior corneal stroma after CXL treatment seems to increase significantly, while the posterior stroma does not seem to be

  9. Multiscale Investigation of the Depth-Dependent Mechanical Anisotropy of the Human Corneal Stroma

    PubMed Central

    Labate, Cristina; Lombardo, Marco; De Santo, Maria P.; Dias, Janice; Ziebarth, Noel M.; Lombardo, Giuseppe

    2015-01-01

    Purpose. To investigate the depth-dependent mechanical anisotropy of the human corneal stroma at the tissue (stroma) and molecular (collagen) level by using atomic force microscopy (AFM). Methods. Eleven human donor corneas were dissected at different stromal depths by using a microkeratome. Mechanical measurements were performed in 15% dextran on the surface of the exposed stroma of each sample by using a custom-built AFM in force spectroscopy mode using both microspherical (38-μm diameter) and nanoconical (10-nm radius of curvature) indenters at 2-μm/s and 15-μm/s indentation rates. Young's modulus was determined by fitting force curve data using the Hertz and Hertz-Sneddon models for a spherical and a conical indenter, respectively. The depth-dependent anisotropy of stromal elasticity was correlated with images of the corneal stroma acquired by two-photon microscopy. Results. The force curves were obtained at stromal depths ranging from 59 to 218 μm. At the tissue level, Young's modulus (ES) showed a steep decrease at approximately 140-μm stromal depth (from 0.8 MPa to 0.3 MPa; P = 0.03) and then was stable in the posterior stroma. At the molecular level, Young's modulus (EC) was significantly greater than at the tissue level; EC decreased nonlinearly with increasing stromal depth from 3.9 to 2.6 MPa (P = 0.04). The variation of microstructure through the thickness correlated highly with a nonconstant profile of the mechanical properties in the stroma. Conclusions. The corneal stroma exhibits unique anisotropic elastic behavior at the tissue and molecular levels. This knowledge may benefit modeling of corneal behavior and help in the development of biomimetic materials. PMID:26098472

  10. Tumor cell-specific bioluminescence platform to identify stroma-induced changes to anticancer drug activity.

    PubMed

    McMillin, Douglas W; Delmore, Jake; Weisberg, Ellen; Negri, Joseph M; Geer, D Corey; Klippel, Steffen; Mitsiades, Nicholas; Schlossman, Robert L; Munshi, Nikhil C; Kung, Andrew L; Griffin, James D; Richardson, Paul G; Anderson, Kenneth C; Mitsiades, Constantine S

    2010-04-01

    Conventional anticancer drug screening is typically performed in the absence of accessory cells of the tumor microenvironment, which can profoundly alter antitumor drug activity. To address this limitation, we developed the tumor cell-specific in vitro bioluminescence imaging (CS-BLI) assay. Tumor cells (for example, myeloma, leukemia and solid tumors) stably expressing luciferase are cultured with nonmalignant accessory cells (for example, stromal cells) for selective quantification of tumor cell viability, in presence versus absence of stromal cells or drug treatment. CS-BLI is high-throughput scalable and identifies stroma-induced chemoresistance in diverse malignancies, including imatinib resistance in leukemic cells. A stroma-induced signature in tumor cells correlates with adverse clinical prognosis and includes signatures for activated Akt, Ras, NF-kappaB, HIF-1alpha, myc, hTERT and IRF4; for biological aggressiveness; and for self-renewal. Unlike conventional screening, CS-BLI can also identify agents with increased activity against tumor cells interacting with stroma. One such compound, reversine, shows more potent activity in an orthotopic model of diffuse myeloma bone lesions than in conventional subcutaneous xenografts. Use of CS-BLI, therefore, enables refined screening of candidate anticancer agents to enrich preclinical pipelines with potential therapeutics that overcome stroma-mediated drug resistance and can act in a synthetic lethal manner in the context of tumor-stroma interactions. PMID:20228816

  11. Thylakoid direct photobioelectrocatalysis: utilizing stroma thylakoids to improve bio-solar cell performance.

    PubMed

    Rasmussen, Michelle; Minteer, Shelley D

    2014-08-28

    Thylakoid membranes from spinach were separated into grana and stroma thylakoid fractions which were characterized by several methods (pigment content, protein gel electrophoresis, photosystem activities, and electron microscopy analysis) to confirm that the intact thylakoids were differentiated into the two domains. The results of photoelectrochemical experiments showed that stroma thylakoid electrodes generate photocurrents more than four times larger than grana thylakoids (51 ± 4 nA cm(-2) compared to 11 ± 1 nA cm(-2)). A similar trend was seen in a bio-solar cell configuration with stroma thylakoids giving almost twice the current (19 ± 3 μA cm(-2)) as grana thylakoids (11 ± 2 μA cm(-2)) with no change in open circuit voltage. PMID:25019197

  12. Integrated Bioinformatics Approach Reveals Crosstalk Between Tumor Stroma and Peripheral Blood Mononuclear Cells in Breast Cancer.

    PubMed

    He, Lang; Wang, Dan; Wei, Na; Guo, Zheng

    2016-01-01

    Breast cancer is now the leading cause of cancer death in women worldwide. Cancer progression is driven not only by cancer cell intrinsic alterations and interactions with tumor microenvironment, but also by systemic effects. Integration of multiple profiling data may provide insights into the underlying molecular mechanisms of complex systemic processes. We performed a bioinformatic analysis of two public available microarray datasets for breast tumor stroma and peripheral blood mononuclear cells, featuring integrated transcriptomics data, protein-protein interactions (PPIs) and protein subcellular localization, to identify genes and biological pathways that contribute to dialogue between tumor stroma and the peripheral circulation. Genes of the integrin family as well as CXCR4 proved to be hub nodes of the crosstalk network and may play an important role in response to stroma-derived chemoattractants. This study pointed to potential for development of therapeutic strategies that target systemic signals travelling through the circulation and interdict tumor cell recruitment. PMID:27039717

  13. Emerging roles of the tumor-associated stroma in promoting tumor metastasis

    PubMed Central

    Horimoto, Yoshiya; Polanska, Urszula M.; Takahashi, Yuko; Orimo, Akira

    2012-01-01

    The stroma in human carcinomas consists of extracellular matrix and various types of non-carcinoma cells, mainly leukocytes, endothelial cells, fibroblasts, myofibroblasts and bone marrow-derived progenitors. The tumor-associated stroma actively supports tumor growth by stimulating neo-angiogenesis, as well as proliferation and invasion of apposed carcinoma cells. It has long been accepted that alterations within carcinoma cells mediate metastasis in a cell-autonomous fashion. Recent studies have, however, suggested an additional notion that cancer cells instigate local and systemic changes in the tumor microenvironment and contribute to niche formation for metastasis. Research, aiming to establish the roles of the tumor-associated stroma in facilitating the spread of carcinoma cells into distant organs, has provided an abundance of data and greater knowledge of the biology of metastatic carcinoma cells and associated stromal cells. This has stimulated further advances in the development of novel therapeutic approaches targeting tumor metastasis. PMID:22568980

  14. A Rare Case of Renal Cell Carcinoma With Leiomyomatous Stroma and Concomitant Ruptured Adrenal Aneurysm.

    PubMed

    Lu, Chuanyong; Nicastri, Anthony; Shao, Charles

    2016-09-01

    Here we report a rare case of coexisting renal cell carcinoma (RCC) with leiomyomatous stroma and a ruptured adrenal aneurysm. The patient was a 75-year-old woman with acute abdominal pain. Imaging studies showed a left peri-renal hematoma and a mass in the left kidney. Left nephrectomy and adrenalectomy were performed. Pathological examination showed a ruptured aneurysm in the left adrenal gland. The renal mass was composed of tubules and acini of epithelial cells and a prominent leiomyomatous stroma. The tumor cells were positive for carbonic anhydrase IX, cytokeratin 7, and negative for AMACR, consistent with clear cell (tubulo) papillary RCC. PMID:27516974

  15. Corneal Opacity in Lumican-Null Mice: Defects in Collagen Fibril Structure and Packing in the Posterior Stroma

    PubMed Central

    Chakravarti, Shukti; Petroll, W. Matthew; Hassell, John R.; Jester, James V.; Lass, Jonathan H.; Paul, Jennifer; Birk, David E.

    2015-01-01

    Purpose Gene targeted lumican-null mutants (lumtm1sc/lumtm1sc) have cloudy corneas with abnormally thick collagen fibrils. The purpose of the present study was to analyze the loss of transparency quantitatively and to define the associated corneal collagen fibril and stromal defects. Methods Backscattering of light, a function of corneal haze and opacification, was determined regionally using in vivo confocal microscopy in lumican-deficient and wild-type control mice. Fibril organization and structure were analyzed using transmission electron microscopy. Biochemical approaches were used to quantify glycosaminoglycan contents. Lumican distribution in the cornea was elucidated immunohistochemically. Results Compared with control stromas, lumican-deficient stromas displayed a threefold increase in backscattered light with maximal increase confined to the posterior stroma. Confocal microscopy through-focusing (CMTF) measurement profiles also indicated a 40% reduction in stromal thickness in the lumican-null mice. Transmission electron microscopy indicated significant collagen fibril abnormalities in the posterior stroma, with the anterior stroma remaining relatively unremarkable. The lumican-deficient posterior stroma displayed a pronounced increase in fibril diameter, large fibril aggregates, altered fibril packing, and poor lamellar organization. Immunostaining of wild-type corneas demonstrated high concentrations of lumican in the posterior stroma. Biochemical assessment of keratan sulfate (KS) content of whole eyes revealed a 25% reduction in KS content in the lumican-deficient mice. Conclusions The structural defects and maximum backscattering of light clearly localized to the posterior stroma of lumican-deficient mice. In normal mice, an enrichment of lumican was observed in the posterior stroma compared with that in the anterior stroma. Taken together, these observations indicate a key role for lumican in the posterior stroma in maintaining normal fibril

  16. Penrose inequality and apparent horizons

    SciTech Connect

    Ben-Dov, Ishai

    2004-12-15

    A spherically symmetric spacetime is presented with an initial data set that is asymptotically flat, satisfies the dominant energy condition, and such that on this initial data M<{radical}(A/16{pi}), where M is the total mass and A is the area of the apparent horizon. This provides a counterexample to a commonly stated version of the Penrose inequality, though it does not contradict the true Penrose inequality.

  17. Tic40 is important for reinsertion of proteins from the chloroplast stroma into the inner membrane

    PubMed Central

    Chiu, Chi-Chou; Li, Hsou-min

    2008-01-01

    Chloroplast inner-membrane proteins Tic40 and Tic110 are first imported from the cytosol into the chloroplast stroma, and subsequently reinserted from the stroma into the inner membrane. However, the mechanism of reinsertion remains unclear. Here we show that Tic40 itself is involved in this reinsertion process. When precursors of either Tic40 or a Tic110 C-terminal truncate, tpTic110-Tic110N, were imported into chloroplasts isolated from a tic40-null mutant, soluble Tic40 and Tic110N intermediates accumulated in the stroma of tic40-mutant chloroplasts, due to a slower rate of reinsertion. We further show that a larger quantity of soluble Tic21 intermediates also accumulated in the stroma of tic40-mutant chloroplasts. In contrast, inner-membrane insertion of the triose-phosphate/phosphate translocator was not affected by the tic40 mutation. Our data suggest that multiple pathways exist for the insertion of chloroplast inner-membrane proteins. PMID:18657235

  18. Pathophysiological role of microRNA-29 in pancreatic cancer stroma

    PubMed Central

    Kwon, Jason J.; Nabinger, Sarah C.; Vega, Zachary; Sahu, Smiti Snigdha; Alluri, Ravi K.; Abdul-Sater, Zahi; Yu, Zhangsheng; Gore, Jesse; Nalepa, Grzegorz; Saxena, Romil; Korc, Murray; Kota, Janaiah

    2015-01-01

    Dense fibrotic stroma associated with pancreatic ductal adenocarcinoma (PDAC) is a major obstacle for drug delivery to the tumor bed and plays a crucial role in pancreatic cancer progression. Current, anti-stromal therapies have failed to improve tumor response to chemotherapy and patient survival. Furthermore, recent studies show that stroma impedes tumor progression, and its complete ablation accelerates PDAC progression. In an effort to understand the molecular mechanisms associated with tumor-stromal interactions, using in vitro and in vivo models and PDAC patient biopsies, we show that the loss of miR-29 is a common phenomenon of activated pancreatic stellate cells (PSCs)/fibroblasts, the major stromal cells responsible for fibrotic stromal reaction. Loss of miR-29 is correlated with a significant increase in extracellular matrix (ECM) deposition, a major component in PDAC stroma. Our in vitro miR-29 gain/loss-of-function studies document the role of miR-29 in PSC-mediated ECM stromal protein accumulation. Overexpression of miR-29 in activated stellate cells reduced stromal deposition, cancer cell viability, and cancer growth in co-culture. Furthermore, the loss of miR-29 in TGF-β1 activated PSCs is SMAD3 dependent. These results provide insights into the mechanistic role of miR-29 in PDAC stroma and its potential use as a therapeutic agent to target PDAC. PMID:26095125

  19. Understanding tumor-stroma interplays for targeted therapies by armed mesenchymal stromal progenitors: the Mesenkillers

    PubMed Central

    Grisendi, Giulia; Bussolari, Rita; Veronesi, Elena; Piccinno, Serena; Burns, Jorge S; De Santis, Giorgio; Loschi, Pietro; Pignatti, Marco; Di Benedetto, Fabrizio; Ballarin, Roberto; Di Gregorio, Carmela; Guarneri, Valentina; Piccinini, Lino; Horwitz, Edwin M; Paolucci, Paolo; Conte, PierFranco; Dominici, Massimo

    2011-01-01

    A tumor represents a complex structure containing malignant cells strictly coupled with a large variety of surrounding cells constituting the tumor stroma (TS). In recent years, the importance of TS for cancer initiation, development, local invasion and metastases has become increasingly clear allowing the identification of TS as one of the possible ways to indirectly target tumors. Inside the heterogeneous stromal cell population, tumor associated fibroblasts (TAF) play a crucial role providing both functional and supportive environments. During both tumor and stroma development, several findings suggest that TAF could be recruited from different sources such as locally derived host fibroblasts, via epithelial/endothelial mesenchymal transitions or from circulating pools of fibroblasts deriving form mesenchymal progenitors, namely mesenchymal stem/stromal cells (MSC). These insights prompted scientists to identify multimodal approaches to target TS by biomolecules, monoclonal antibodies, and more recently via cell based strategies. These latter strategies appear extremely promising, although still associated with debated and unclear findings. This review discusses crosstalk between cancers and their stroma, dissecting specific tumor types, such as sarcoma, pancreatic and breast carcinoma, where stroma plays distinct paradigmatic roles. The recognition of these distinct stromal functions may help in planning effective and safer approaches aimed either to eradicate or to substitute TS by novel compounds and/or MSC having specific killing activities. PMID:22016827

  20. Localization, Purification, and Characterization of Shikimate Oxidoreductase-Dehydroquinate Hydrolyase from Stroma of Spinach Chloroplasts 1

    PubMed Central

    Fiedler, Erich; Schultz, Gernot

    1985-01-01

    The stroma of chloroplasts is probably the sole site of the shikimate pathway enzymes shikimate oxidoreductase/dehydroquinate hydrolyase (SORase/DHQase) in spinach leaves. (a) The chromatographic behavior of the bifunctional protein SORase/DHQase on several separation materials with extracts from stroma compared with leaf extracts showed only one peak of enzymic activity originating from the stroma. (b) Polyacrylamide gel electrophoresis (PAGE) of these extracts followed by specific staining resulted in the same pattern without a band of extraplastidic enzyme. (c) In protoplast fractionation experiments it was shown that SORase/DHQase was present only in the soluble chloroplast protein fraction. An improved purification procedure for SORase/DHQase from stroma of chloroplasts, yield 40%, 1600 times as pure, gave essentially one protein band on sodium dodecyl sulfate-PAGE. Our results demonstrate that both enzyme functions are carried out by a single polypeptide. Nondenaturing PAGE exhibited a pattern of four bands with SORase/DHQase showing that they differ in charge but not in their molecular weight. Molecular weight was determined to be 67 kilodaltons (gel filtration) and 59 kilodaltons (PAGE) for all four forms. It was proven they were not due to artifacts. The four forms show similar kinetic properties, their Km and pH optima differing only very slightly. Response to some metabolites is reported. Images Fig. 3 Fig. 7 PMID:16664373

  1. TRP channels and STIM/ORAI proteins: sensors and effectors of cancer and stroma cell migration

    PubMed Central

    Nielsen, N; Lindemann, O; Schwab, A

    2014-01-01

    Cancer cells are strongly influenced by host cells within the tumour stroma and vice versa. This leads to the development of a tumour microenvironment with distinct physical and chemical properties that are permissive for tumour progression. The ability to migrate plays a central role in this mutual interaction. Migration of cancer cells is considered as a prerequisite for tumour metastasis and the migration of host stromal cells is required for reaching the tumour site. Increasing evidence suggests that transient receptor potential (TRP) channels and STIM/ORAI proteins affect key calcium-dependent mechanisms implicated in both cancer and stroma cell migration. These include, among others, cytoskeletal remodelling, growth factor/cytokine signalling and production, and adaptation to tumour microenvironmental properties such as hypoxia and oxidative stress. In this review, we will summarize the current knowledge regarding TRP channels and STIM/ORAI proteins in cancer and stroma cell migration. We focus on how TRP channel or STIM/ORAI-mediated Ca2+ signalling directly or indirectly influences cancer and stroma cell migration by affecting the above listed mechanisms. Linked Articles This article is part of a themed section on Cytoskeleton, Extracellular Matrix, Cell Migration, Wound Healing and Related Topics. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-24 PMID:24724725

  2. Inflammation as a Keystone of Bone Marrow Stroma Alterations in Primary Myelofibrosis

    PubMed Central

    Desterke, Christophe; Martinaud, Christophe; Ruzehaji, Nadira; Le Bousse-Kerdilès, Marie-Caroline

    2015-01-01

    Primary myelofibrosis (PMF) is a clonal myeloproliferative neoplasm where severity as well as treatment complexity is mainly attributed to a long lasting disease and presence of bone marrow stroma alterations as evidenced by myelofibrosis, neoangiogenesis, and osteosclerosis. While recent understanding of mutations role in hematopoietic cells provides an explanation for pathological myeloproliferation, functional involvement of stromal cells in the disease pathogenesis remains poorly understood. The current dogma is that stromal changes are secondary to the cytokine “storm” produced by the hematopoietic clone cells. However, despite therapies targeting the myeloproliferation-sustaining clones, PMF is still regarded as an incurable disease except for patients, who are successful recipients of allogeneic stem cell transplantation. Although the clinical benefits of these inhibitors have been correlated with a marked reduction in serum proinflammatory cytokines produced by the hematopoietic clones, further demonstrating the importance of inflammation in the pathological process, these treatments do not address the role of the altered bone marrow stroma in the pathological process. In this review, we propose hypotheses suggesting that the stroma is inflammatory-imprinted by clonal hematopoietic cells up to a point where it becomes “independent” of hematopoietic cell stimulation, resulting in an inflammatory vicious circle requiring combined stroma targeted therapies. PMID:26640324

  3. High levels of EGFR expression in tumor stroma are associated with aggressive clinical features in epithelial ovarian cancer

    PubMed Central

    Wang, Ke; Li, Dan; Sun, Lu

    2016-01-01

    Purpose The aim of this study was to investigate the clinical significance and biological function of epidermal growth factor receptor (EGFR) expressed in tumor stroma of epithelial ovarian cancer. Methods Immunohistological staining of EGFR was evaluated in 242 patients with epithelial ovarian cancer. The correlations of EGFR expression in tumor stroma with clinicopathological features and with the expression level of Ki-67 were analyzed by SPSS software. Kaplan–Meier analysis and the Cox proportional hazard model were used to analyze the effect of EGFR expression in tumor stroma on the prognosis of patients with epithelial ovarian cancer. Meanwhile, the activities of proliferation and migration of tumor cells were detected when EGFR overexpressed in stroma cells. Results EGFR expression in tumor stroma correlated significantly with clinical stage (χ2=7.002, P=0.008) and distant metastases (χ2=16.59, P<0.001). Furthermore, there was a significantly positive correlation between the level of EGFR expressed in tumor stroma and the level of Ki-67 expressed in tumor cells (χ2=6.120, P=0.013). Patients with high EGFR expression level in tumor stroma showed poor survival (P=0.002). Multivariate analysis showed that high expression of EGFR in tumor stroma was an independent predictor for epithelial ovarian cancer patients (hazard ratio =1.703; 95% confidence interval 1.125–2.578, P=0.012). Furthermore, stroma cells overexpressing EGFR could promote the proliferation and migration of adjacent tumor cells. Conclusion High expression of EGFR in tumor stroma correlates with aggressive clinical features in epithelial ovarian cancer, and is an independent prognostic factor. PMID:26855586

  4. Differential expression of miRNAs in pancreatobiliary type of periampullary adenocarcinoma and its associated stroma.

    PubMed

    Sandhu, V; Bowitz Lothe, I M; Labori, K J; Skrede, M L; Hamfjord, J; Dalsgaard, A M; Buanes, T; Dube, G; Kale, M M; Sawant, S; Kulkarni-Kale, U; Børresen-Dale, A-L; Lingjærde, O C; Kure, E H

    2016-02-01

    Periampullary adenocarcinomas can be of two histological subtypes, intestinal or pancreatobiliary. The latter is more frequent and aggressive, and characterized by a prominent desmoplastic stroma, which is tightly related to the biology of the cancer, including its poor response to chemotherapy. Whereas miRNAs are known to regulate various cellular processes and interactions between cells, their exact role in periampullary carcinoma remains to be characterized, especially with respect to the prominent stromal component of pancreatobiliary type cancers. The present study aimed at elucidating this role by miRNA expression profiling of the carcinomatous and stromal component in twenty periampullary adenocarcinomas of pancreatobiliary type. miRNA expression profiles were compared between carcinoma cells, stromal cells and normal tissue samples. A total of 43 miRNAs were found to be differentially expressed between carcinoma and stroma of which 11 belong to three miRNA families (miR-17, miR-15 and miR-515). The levels of expression of miRNAs miR-17, miR-20a, miR-20b, miR-223, miR-10b, miR-2964a and miR-342 were observed to be higher and miR-519e to be lower in the stromal component compared to the carcinomatous and normal components. They follow a trend where expression in stroma is highest followed by carcinoma and then normal tissue. Pathway analysis revealed that pathways regulating tumor-stroma interactions such as ECM interaction remodeling, epithelial-mesenchymal transition, focal adhesion pathway, TGF-beta, MAPK signaling, axon guidance and endocytosis were differently regulated. The miRNA-mRNA mediated interactions between carcinoma and stromal cells add new knowledge regarding tumor-stroma interactions. PMID:26590090

  5. Teleost fish scales: a unique biological model for the fabrication of materials for corneal stroma regeneration.

    PubMed

    Takagi, Yasuaki; Ura, Kazuhiro

    2007-03-01

    The corneal stroma is composed of multiple lamellae, each containing closely packed collagen fibrils. The orientation of fibrils in a lamella is parallel, but those in different lamellae are orthogonal. As a result, the corneal stroma has a characteristic orthogonal plywood-like structure. Such a highly-regulated three-dimensional arrangement of collagen fibrils gives strength and transparency to the corneal stroma, but it also presents a challenge in the fabrication of materials to replace it. A bioinspired technology is required to process such materials, but the regulatory mechanism of collagen-fibril orientation is still unknown. The low regenerating activity of the corneal stroma seems to be a major factor preventing progress in this field of research. A similarly highly-ordered arrangement of collagen fibrils can be seen in the basal plates of teleost fish scales. Moreover, the scales have high regenerating ability. When a scale is mechanically lost, a new scale is rapidly regenerated. The cells that produce the basal plates are extremely activated; thus, production of the highly-ordered collagen fibrils is very rapid. Therefore, the regenerating scales should be a uniquely helpful biological model for studying the regulatory mechanism of collagen-fibril orientation. Fish-scale collagen has another advantage for use as a biomaterial: the low probability of zoonotic infection. Therefore, scale collagen is a most promising biomaterial for fabricating three-dimensionally arranged collagen fibers to substitute for the corneal stroma. Three tasks that must be clarified for the bioinspired production of a corneal substitute from fish scale collagen are proposed. PMID:17450830

  6. New avenues for improving pancreatic ductal adenocarcinoma (PDAC) treatment: Selective stroma depletion combined with nano drug delivery.

    PubMed

    Bhaw-Luximon, Archana; Jhurry, Dhanjay

    2015-12-28

    The effectiveness of chemotherapy in PDAC is hampered by the dynamic interaction between stroma and cancer cell. The two opposing schools of thought - non-depletion of the stroma vs its depletion - to better drug efficacy are here discussed. Disrupting stroma-cancer cell interaction to reduce tumor progression and promote apoptosis is identified as the new direction of treatment for PDAC. Clinical data have shown that elimination of fibrosis and blockade of the Hedgehog pathway in stroma effectively promote drug delivery to tumor site and apoptosis. Reduced stiffness of ECM, lower fibrosis, higher permeability and higher blood flow after stroma depletion increase drug delivery. Combination strategies involving selective stroma depletion coupled with chemotherapy is currently proving to be the most efficient at clinical level. Striking the right balance between fibrosis depletion and angiogenesis promotion resulting in enhanced drug delivery and apoptosis is a major challenge. The use of nano drug delivery devices coupled with stroma depletion is emerging as the next phase treatment for PDAC. The breakthrough to combat PDAC will likely be a combination of early diagnosis and the emerging chemotherapy strategies. PMID:26415628

  7. Isolation of an immunosuppressive lectin from Phaseolus vulgaris L. cv Cacahuate using stroma.

    PubMed

    Vargas-Albores, F; Hernández, J; Córdoba, F; Zenteno, E

    1993-11-01

    An immunosuppressive lectin was isolated from seed of Phaseolus vulgaris cv Cacahuate using physically entrapped stroma. The lectin was found to be a 94 kDa tetrameric protein. When 50 micrograms, of this lectin were administered intraperitoneally 2 days before the immunization with sheep red blood cells, humoral response against the immunogen was completely inhibited. Other properties of the protein are discussed. PMID:8248029

  8. Normal stroma suppresses cancer cell proliferation via mechanosensitive regulation of JMJD1a-mediated transcription

    PubMed Central

    Kaukonen, Riina; Mai, Anja; Georgiadou, Maria; Saari, Markku; De Franceschi, Nicola; Betz, Timo; Sihto, Harri; Ventelä, Sami; Elo, Laura; Jokitalo, Eija; Westermarck, Jukka; Kellokumpu-Lehtinen, Pirkko-Liisa; Joensuu, Heikki; Grenman, Reidar; Ivaska, Johanna

    2016-01-01

    Tissue homeostasis is dependent on the controlled localization of specific cell types and the correct composition of the extracellular stroma. While the role of the cancer stroma in tumour progression has been well characterized, the specific contribution of the matrix itself is unknown. Furthermore, the mechanisms enabling normal—not cancer—stroma to provide tumour-suppressive signals and act as an antitumorigenic barrier are poorly understood. Here we show that extracellular matrix (ECM) generated by normal fibroblasts (NFs) is softer than the CAF matrix, and its physical and structural features regulate cancer cell proliferation. We find that normal ECM triggers downregulation and nuclear exit of the histone demethylase JMJD1a resulting in the epigenetic growth restriction of carcinoma cells. Interestingly, JMJD1a positively regulates transcription of many target genes, including YAP/TAZ (WWTR1), and therefore gene expression in a stiffness-dependent manner. Thus, normal stromal restricts cancer cell proliferation through JMJD1a-dependent modulation of gene expression. PMID:27488962

  9. Studies on the mechanism of edematous changes at the endometrial stroma for implantation.

    PubMed

    Okada, Y; Asahina, T; Kobayashi, T; Goto, J; Terao, T

    2001-01-01

    The endometrium undergoes edematous changes during the implantation period. Many factors may be involved in these biochemical reactions. We investigated the localization of inducible NO synthase (iNOS), interleukin-8 (IL-8), mast cell tryptase, neutrophil elastase, type III collagen, and CD44 in human endometrium. Immunohistochemical staining was performed by the labeled streptavidin-biotin method. iNOS was stained in the entire endometrial tissue from the midproliferative phase. The IL-8-positive cells, mast cells, and neutrophil elastase in the stroma increased toward the early to midsecretory phase. Type III collagen was arranged regularly in the stromal extracellular matrix during the proliferative phase; however, it was dissected during the secretory phase. CD44 was detected around stromal cells in the midsecretory phase. From these results, we propose the following mechanism. Initially, iNOS, expressed by the entire endometrial tissues from the midproliferative phase, catalyzes the production of NO. NO stimulates cells, supposed to be mast cells, to produce IL-8, which lets neutrophils migrate into the stroma. Neutrophils secrete elastase, which degrades type III collagen, generating spaces in the stroma. Hyaluronic acid adheres to CD44 around the stromal cells and retains water intermolecularly, finally forming the edematous matrix. PMID:11372773

  10. Normal stroma suppresses cancer cell proliferation via mechanosensitive regulation of JMJD1a-mediated transcription.

    PubMed

    Kaukonen, Riina; Mai, Anja; Georgiadou, Maria; Saari, Markku; De Franceschi, Nicola; Betz, Timo; Sihto, Harri; Ventelä, Sami; Elo, Laura; Jokitalo, Eija; Westermarck, Jukka; Kellokumpu-Lehtinen, Pirkko-Liisa; Joensuu, Heikki; Grenman, Reidar; Ivaska, Johanna

    2016-01-01

    Tissue homeostasis is dependent on the controlled localization of specific cell types and the correct composition of the extracellular stroma. While the role of the cancer stroma in tumour progression has been well characterized, the specific contribution of the matrix itself is unknown. Furthermore, the mechanisms enabling normal-not cancer-stroma to provide tumour-suppressive signals and act as an antitumorigenic barrier are poorly understood. Here we show that extracellular matrix (ECM) generated by normal fibroblasts (NFs) is softer than the CAF matrix, and its physical and structural features regulate cancer cell proliferation. We find that normal ECM triggers downregulation and nuclear exit of the histone demethylase JMJD1a resulting in the epigenetic growth restriction of carcinoma cells. Interestingly, JMJD1a positively regulates transcription of many target genes, including YAP/TAZ (WWTR1), and therefore gene expression in a stiffness-dependent manner. Thus, normal stromal restricts cancer cell proliferation through JMJD1a-dependent modulation of gene expression. PMID:27488962

  11. An imported thylakoid protein accumulates in the stroma when insertion into thylakoids is inhibited.

    PubMed

    Cline, K; Fulsom, D R; Viitanen, P V

    1989-08-25

    The light-harvesting chlorophyll a/b protein (LHCP) is synthesized in the cytosol as a precursor (pLHCP) that is imported into chloroplasts and assembled into thylakoid membranes. Under appropriate conditions, either pLHCP or LHCP will integrate into isolated thylakoids. We have identified two situations that inhibit integration in this assay. Ionophores and uncouplers inhibited integration up to 70%. Carboxyl-terminal truncations of pLHCP also interfered with integration. A 22-residue truncation reduced integration to about 25% of control, whereas a 93 residue truncation completely abolished it. When pLHCP was imported into chloroplasts in the presence of uncouplers or when truncated forms of pLHCP were used, significant amounts of the imported proteins failed to insert into thylakoids and instead accumulated in the aqueous stroma. Accumulation of stromal LHCP occurred at uncoupler concentrations required to dissipate the trans-thylakoid proton electrochemical gradient and was enhanced at reduced levels of ATP. The latter effect may be a secondary consequence of a reduction in ATP-dependent degradation within the stroma. These results indicate that the stroma is an intermediate location in the LHCP assembly pathway and provide the first evidence for a soluble intermediate during biogenesis of a chloroplast membrane protein. PMID:2668283

  12. Digital histologic analysis reveals morphometric patterns of age-related involution in breast epithelium and stroma.

    PubMed

    Sandhu, Rupninder; Chollet-Hinton, Lynn; Kirk, Erin L; Midkiff, Bentley; Troester, Melissa A

    2016-02-01

    Complete age-related regression of mammary epithelium, often termed postmenopausal involution, is associated with decreased breast cancer risk. However, most studies have qualitatively assessed involution. We quantitatively analyzed epithelium, stroma, and adipose tissue from histologically normal breast tissue of 454 patients in the Normal Breast Study. High-resolution digital images of normal breast hematoxylin and eosin-stained slides were partitioned into epithelium, adipose tissue, and nonfatty stroma. Percentage area and nuclei per unit area (nuclear density) were calculated for each component. Quantitative data were evaluated in association with age using linear regression and cubic spline models. Stromal area decreased (P = 0.0002), and adipose tissue area increased (P < 0.0001), with an approximate 0.7% change in area for each component, until age 55 years when these area measures reached a steady state. Although epithelial area did not show linear changes with age, epithelial nuclear density decreased linearly beginning in the third decade of life. No significant age-related trends were observed for stromal or adipose nuclear density. Digital image analysis offers a high-throughput method for quantitatively measuring tissue morphometry and for objectively assessing age-related changes in adipose tissue, stroma, and epithelium. Epithelial nuclear density is a quantitative measure of age-related breast involution that begins to decline in the early premenopausal period. PMID:26772400

  13. Lysyl hydroxylase 2 induces a collagen cross-link switch in tumor stroma

    PubMed Central

    Chen, Yulong; Terajima, Masahiko; Yang, Yanan; Sun, Li; Ahn, Young-Ho; Pankova, Daniela; Puperi, Daniel S.; Watanabe, Takeshi; Kim, Min P.; Blackmon, Shanda H.; Rodriguez, Jaime; Liu, Hui; Behrens, Carmen; Wistuba, Ignacio I.; Minelli, Rosalba; Scott, Kenneth L.; Sanchez-Adams, Johannah; Guilak, Farshid; Pati, Debananda; Thilaganathan, Nishan; Burns, Alan R.; Creighton, Chad J.; Martinez, Elisabeth D.; Zal, Tomasz; Grande-Allen, K. Jane; Yamauchi, Mitsuo; Kurie, Jonathan M.

    2015-01-01

    Epithelial tumor metastasis is preceded by an accumulation of collagen cross-links that heighten stromal stiffness and stimulate the invasive properties of tumor cells. However, the biochemical nature of collagen cross-links in cancer is still unclear. Here, we postulated that epithelial tumorigenesis is accompanied by changes in the biochemical type of collagen cross-links. Utilizing resected human lung cancer tissues and a p21CIP1/WAF1-deficient, K-rasG12D-expressing murine metastatic lung cancer model, we showed that, relative to normal lung tissues, tumor stroma contains higher levels of hydroxylysine aldehyde–derived collagen cross-links (HLCCs) and lower levels of lysine aldehyde–derived cross-links (LCCs), which are the predominant types of collagen cross-links in skeletal tissues and soft tissues, respectively. Gain- and loss-of-function studies in tumor cells showed that lysyl hydroxylase 2 (LH2), which hydroxylates telopeptidyl lysine residues on collagen, shifted the tumor stroma toward a high-HLCC, low-LCC state, increased tumor stiffness, and enhanced tumor cell invasion and metastasis. Together, our data indicate that LH2 enhances the metastatic properties of tumor cells and functions as a regulatory switch that controls the relative abundance of biochemically distinct types of collagen cross-links in the tumor stroma. PMID:25664850

  14. A novel method in preparation of acellularporcine corneal stroma tissue for lamellar keratoplasty

    PubMed Central

    Shao, Yi; Tang, Jing; Zhou, Yueping; Qu, Yangluowa; He, Hui; Liu, Qiuping; Tan, Gang; Li, Wei; Liu, Zuguo

    2015-01-01

    Our objective was to develop a novel lamellar cornealbiomaterial for corneal reconstruction.Theporcine acellular corneal stroma discs (ACSDs) were prepared from de-epithelized fresh porcine corneas (DFPCs) by incubation with 100% fresh human serum and additional electrophoresis at 4°C. Such manipulation removed theanterior corneal stromal cells without residual of DNA content and α-Galantigen. Human serum decellularizing activity on porcineanterior corneal stroma cells is through apoptosis, and associated with the presence of α-Gal epitopes in anterior stroma. ACSDs displayed similar optical, biomechanical properties and ultrastructure to DFPCs, and showed good histocompatibility in rabbit corneal stromal pockets and anterior chamber. Rabbit corneallamellar keratoplasty (LKP) using ACSDs showed no rejection and high transparency of cornea at 2 months after surgery. In vivo confocal laser scanning microscopy and immunostaining analysis showed complete re-epithelization and stromal cell in growth of ACSDs without inflammatory cell infiltration, new blood vessel ingrowth and excessive wound healing. In conclusion, this novel decellularization method may be valuable for preparation of xenogenic corneal tissue for clinical application, ACSDs resulted from this method may be served as a matrix equivalent for LKP in corneal xenotransplantation. PMID:26885261

  15. Targeting the leukemia–stroma interaction in acute myeloid leukemia: rationale and latest evidence

    PubMed Central

    Rashidi, Armin; DiPersio, John F.

    2016-01-01

    The concept of ‘niche’ has become a focus of attention in hematologic malignancies including acute myeloid leukemia (AML). Similar to normal hematopoietic stem cells, AML cells interact both anatomically and functionally with the stroma within the marrow microenvironment. These interactions have a critical role in the development, progression, and relapse of AML. Chemotherapy resistance is another feature that is at least partially related to AML–stroma interactions. The evidence for safety and efficacy of agents targeting AML–niche interactions is currently limited to preclinical and early phase clinical studies. Examples include CXCR4 inhibitors, hypoxia-inducible agents, and adhesion molecule inhibitors. Agents that target AML–stroma interactions differ from mutation-specific approaches that tend to be limited due to within-individual and between-individual genetic heterogeneity. These agents may be used alone or as chemosensitizers in AML. This novel and rapidly advancing strategy is likely to become an important part of our armamentarium of anti-leukemia treatments in the near future. PMID:26834953

  16. GT198 Expression Defines Mutant Tumor Stroma in Human Breast Cancer.

    PubMed

    Yang, Zheqiong; Peng, Min; Cheng, Liang; Jones, Kimya; Maihle, Nita J; Mivechi, Nahid F; Ko, Lan

    2016-05-01

    Human breast cancer precursor cells remain to be elucidated. Using breast cancer gene product GT198 (PSMC3IP; alias TBPIP or Hop2) as a unique marker, we revealed the cellular identities of GT198 mutant cells in human breast tumor stroma. GT198 is a steroid hormone receptor coactivator and a crucial factor in DNA repair. Germline mutations in GT198 are present in breast and ovarian cancer families. Somatic mutations in GT198 are present in ovarian tumor stromal cells. Herein, we show that human breast tumor stromal cells carry GT198 somatic mutations and express cytoplasmic GT198 protein. GT198(+) stromal cells share vascular smooth muscle cell origin, including myoepithelial cells, adipocytes, capillary pericytes, and stromal fibroblasts. Frequent GT198 mutations are associated with GT198(+) tumor stroma but not with GT198(-) tumor cells. GT198(+) progenitor cells are mostly capillary pericytes. When tested in cultured cells, mutant GT198 induces vascular endothelial growth factor promoter, and potentially promotes angiogenesis and adipogenesis. Our results suggest that multiple lineages of breast tumor stromal cells are mutated in GT198. These findings imply the presence of mutant progenitors, whereas their descendants, carrying the same GT198 mutations, are collectively responsible for forming breast tumor microenvironment. GT198 expression is, therefore, a specific marker of mutant breast tumor stroma and has the potential to facilitate diagnosis and targeted treatment of human breast cancer. PMID:27001628

  17. Gangliosides of myelosupportive stroma cells are transferred to myeloid progenitors and are required for their survival and proliferation

    PubMed Central

    Ziulkoski, Ana L.; Andrade, Cláudia M. B.; Crespo, Pilar M.; Sisti, Elisa; Trindade, Vera M. T.; Daniotti, Jose L.; Guma, Fátima C. R.; Borojevic, Radovan

    2005-01-01

    In previous studies, we have shown that the myelopoiesis dependent upon myelosupportive stroma required production of growth factors and heparan-sulphate proteoglycans, as well as generation of a negatively charged sialidase-sensitive intercellular environment between the stroma and the myeloid progenitors. In the present study, we have investigated the production, distribution and role of gangliosides in an experimental model of in vitro myelopoiesis dependent upon AFT-024 murine liver-derived stroma. We used the FDC-P1 cell line, which is dependent upon GM-CSF (granulocyte/macrophage colony-stimulating factor) for both survival and proliferation, as a reporter system to monitor bioavailability and local activity of GM-CSF. GM3 was the major ganglioside produced by stroma, but not by myeloid cells, and it was required for optimal stroma myelosupportive function. It was released into the supernatant and selectively incorporated into the myeloid progenitor cells, where it segregated into rafts in which it co-localized with the GM-CSF-receptor α chain. This ganglioside was also metabolized further by myeloid cells into gangliosides of the a and b series, similar to endogenous GM3. In these cells, GM1 was the major ganglioside and it was segregated at the interface by stroma and myeloid cells, partially co-localizing with the GM-CSF-receptor α chain. We conclude that myelosupportive stroma cells produce and secrete the required growth factors, the cofactors such as heparan sulphate proteoglycans, and also supply gangliosides that are transferred from stroma to target cells, generating on the latter ones specific membrane domains with molecular complexes that include growth factor receptors. PMID:16321139

  18. Tbx18 Regulates the Differentiation of Periductal Smooth Muscle Stroma and the Maintenance of Epithelial Integrity in the Prostate

    PubMed Central

    Guimarães-Camboa, Nuno; Zhang, Huimin; Troy, Joseph M.; Lu, Xiaochen; Kispert, Andreas; Evans, Sylvia M.; Stubbs, Lisa

    2016-01-01

    The T-box transcription factor TBX18 is essential to mesenchymal cell differentiation in several tissues and Tbx18 loss-of-function results in dramatic organ malformations and perinatal lethality. Here we demonstrate for the first time that Tbx18 is required for the normal development of periductal smooth muscle stromal cells in prostate, particularly in the anterior lobe, with a clear impact on prostate health in adult mice. Prostate abnormalities are only subtly apparent in Tbx18 mutants at birth; to examine postnatal prostate development we utilized a relatively long-lived hypomorphic mutant and a novel conditional Tbx18 allele. Similar to the ureter, cells that fail to express Tbx18 do not condense normally into smooth muscle cells of the periductal prostatic stroma. However, in contrast to ureter, the periductal stromal cells in mutant prostate assume a hypertrophic, myofibroblastic state and the adjacent epithelium becomes grossly disorganized. To identify molecular events preceding the onset of this pathology, we compared gene expression in the urogenital sinus (UGS), from which the prostate develops, in Tbx18-null and wild type littermates at two embryonic stages. Genes that regulate cell proliferation, smooth muscle differentiation, prostate epithelium development, and inflammatory response were significantly dysregulated in the mutant urogenital sinus around the time that Tbx18 is first expressed in the wild type UGS, suggesting a direct role in regulating those genes. Together, these results argue that Tbx18 is essential to the differentiation and maintenance of the prostate periurethral mesenchyme and that it indirectly regulates epithelial differentiation through control of stromal-epithelial signaling. PMID:27120339

  19. Keratinocyte-Derived Chemokine Induces Prostate Epithelial Hyperplasia and Reactive Stroma in a Novel Transgenic Mouse Model

    PubMed Central

    Schauer, Isaiah G.; Ressler, Steven J.; Rowley, David R.

    2009-01-01

    Background Interleukin-8 (IL-8) is upregulated in fibrotic and malignant diseases and is a key mediator of proliferative responses. Elevated IL-8 was recently correlated with benign prostatic hyperplasia epithelium and a myofibroblast reactive stroma. Thus, we sought to determine whether overexpressed IL-8 and keratinocyte-derived chemokine (KC), the functional murine homolog of IL-8, induce prostate epithelial hyperplasia and a reactive phenotype. Methods Transgenic mice that overexpress KC within prostate epithelia and xenograft models with engineered human cells that overexpress IL-8 were developed. Results Overexpression of KC in transgenic mice produced hyperplastic prostate epithelial acini associated with a periacinar reactive stroma. KC induced an altered epithelial/stroma proliferation index ratio, increased acini diameter, epithelial infolding, and expression of prototypical reactive stroma markers. Overexpression of IL-8 in normal human prostate epithelial xenografts correlated with elevated epithelial proliferation index and altered morphology. Elevated human prostate stromal and epithelial cell proliferation, nodule-like morphology and increased xenograft survival were observed in IL-8-overexpressing orthotopic xenografts. Conclusions Together, these data demonstrate that overexpression of IL-8/KC results in a prostate epithelial hyperplasia with an associated reactive stroma phenotype. The novel transgenic mouse and human xenograft models described here may be useful in dissecting key mechanisms of IL-8 induced prostate hyperplasia and reactive stroma. PMID:19021203

  20. Reproductive age-associated fibrosis in the stroma of the mammalian ovary.

    PubMed

    Briley, Shawn M; Jasti, Susmita; McCracken, Jennifer M; Hornick, Jessica E; Fegley, Barbara; Pritchard, Michele T; Duncan, Francesca E

    2016-09-01

    Under normal physiological conditions, tissue remodeling in response to injury leads to tissue regeneration without permanent damage. However, if homeostasis between synthesis and degradation of extracellular matrix (ECM) components is altered, fibrosis - or the excess accumulation of ECM - can disrupt tissue architecture and function. Several organs, including the heart, lung and kidney, exhibit age-associated fibrosis. Here we investigated whether fibrosis underlies aging in the ovary - an organ that ages chronologically before other organs. We used Picrosirius Red (PSR), a connective tissue stain specific for collagen I and III fibers, to evaluate ovarian fibrosis. Using bright-field, epifluorescence, confocal and polarized light microscopy, we validated the specific staining of highly ordered PSR-stained fibers in the ovary. We next examined ovarian PSR staining in two mouse strains (CD1 and CB6F1) across an aging continuum and found that PSR staining was minimal in ovaries from reproductively young adult animals, increased in distinct foci in animals of mid-to-advanced reproductive age, and was prominent throughout the stroma of the oldest animals. Consistent with fibrosis, there was a reproductive age-associated increase in ovarian hydroxyproline content. We also observed a unique population of multinucleated macrophage giant cells, which are associated with chronic inflammation, within the ovarian stroma exclusively in reproductively old mice. In fact, several genes central to inflammation had significantly higher levels of expression in ovaries from reproductively old mice relative to young mice. These results establish fibrosis as an early hallmark of the aging ovarian stroma, and this altered microenvironment may contribute to the age-associated decline in gamete quality. PMID:27491879

  1. Antagonizing the Hedgehog Pathway with Vismodegib Impairs Malignant Pleural Mesothelioma Growth In Vivo by Affecting Stroma.

    PubMed

    Meerang, Mayura; Bérard, Karima; Felley-Bosco, Emanuela; Lauk, Olivia; Vrugt, Bart; Boss, Andreas; Kenkel, David; Broggini-Tenzer, Angela; Stahel, Rolf A; Arni, Stephan; Weder, Walter; Opitz, Isabelle

    2016-05-01

    An autocrine-driven upregulation of the Hedgehog (Hh) signaling pathway has been described in malignant pleural mesothelioma (MPM), in which the ligand, desert Hh (DHH), was produced from tumor cells. However, our investigation revealed that the Hh pathway is activated in both tumor and stroma of MPM tumor specimens and an orthotopic immunocompetent rat MPM model. This was demonstrated by positive immunohistochemical staining of Glioma-associated oncogene 1 (GLI1) and Patched1 (PTCH1) in both tumor and stromal fractions. DHH was predominantly expressed in the tumor fractions. To further investigate the role of the Hh pathway in MPM stroma, we antagonized Hh signaling in the rat model of MPM using a Hh antagonist, vismodegib, (100 mg/kg orally). Daily treatment with vismodegib efficiently downregulated Hh target genes Gli1, Hedgehog Interacting Protein (Hhip), and Ptch1, and caused a significant reduction of tumor volume and tumor growth delay. Immunohistochemical analyses revealed that vismodegib treatment primarily downregulated GLI1 and HHIP in the stromal compartment along with a reduced expression of previously described fibroblast Hh-responsive genes such as Fibronectin (Fn1) and Vegfa Primary cells isolated from the rat model cultured in 3% O2 continued to express Dhh but did not respond to vismodegib in vitro However, culture supernatant from these cells stimulated Gli1, Ptch1, and Fn1 expression in mouse embryonic fibroblasts, which was suppressed by vismodegib. Our study provides new evidence regarding the role of Hh signaling in MPM stroma in the maintenance of tumor growth, emphasizing Hh signaling as a treatment target for MPM. Mol Cancer Ther; 15(5); 1095-105. ©2016 AACR. PMID:26839306

  2. Columnar cell lesions and pseudoangiomatous hyperplasia like stroma: is there an epithelial-stromal interaction?

    PubMed

    Recavarren, Rosemary A; Chivukula, Mamatha; Carter, Gloria; Dabbs, David J

    2009-01-01

    The significance of association between cancer and its microenvironment has been increasingly recognized. It has been shown in animal models that interaction between neoplastic epithelial cells and adjacent stroma can modulate tumor behavior. Carcinoma associated stromal cells can transform normal epithelial cells into neoplastic cells. In breast, columnar cell lesions are non-obligate precursors of low grade ductal carcinoma in situ. Columnar cell lesions can be seen intimately associated with PASH-like-stroma, a lesion we termed as CCPLS. Our aim is to investigate epithelial-stromal interactions in CCPLS and compare them to PASH without columnar cell lesions in breast core needle biopsies. Normal terminal duct lobular unit (TDLU) epithelium was seen in association with columnar cell lesions as well as PASH. Eight (8) cases of each category were examined by a panel of immunostains: CD117 (C-kit), CD34, CD105, bFGF, AR, ER-beta, MIB-1. We observed a markedly decreased expression of c-kit in columnar cell lesions compared to TDLU-epithelium. CD105 showed a quantitative increase in activated vessels in CCPLS compared to PASH. A subset of CCPLS and PASH were androgen receptor positive. A strong nuclear positivity for ER-beta is observed in the epithelium and stroma of all CCPLS cases. We conclude that (1) activated blood vessels predominate in CCPLS; (2) A molecular alteration is signified by c-kit loss in columnar cell lesions; (3) ER-beta and androgen receptor positivity indicate CCPLS are hormonally responsive lesions. Our study suggests an intimate vascular and hormone dependent epithelial-stromal interaction exists in CCPLS lesions. PMID:19918332

  3. Altered Proteomic Polymorphisms in the Caterpillar Body and Stroma of Natural Cordyceps sinensis during Maturation

    PubMed Central

    Wu, Zi-Mei; Gao, Ling; Yao, Yi-Sang; Tan, Ning-Zhi; Wu, Jian-Yong; Ni, Luqun; Zhu, Jia-Shi

    2014-01-01

    Objective To examine the maturational changes in proteomic polymorphisms resulting from differential expression by multiple intrinsic fungi in the caterpillar body and stroma of natural Cordyceps sinensis (Cs), an integrated micro-ecosystem. Methods The surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) biochip technique was used to profile the altered protein compositions in the caterpillar body and stroma of Cs during its maturation. The MS chromatograms were analyzed using density-weighted algorithms to examine the similarities and cluster relationships among the proteomic polymorphisms of the Cs compartments and the mycelial products Hirsutella sinensis (Hs) and Paecilomyces hepiali (Ph). Results: SELDI-TOF MS chromatograms displayed dynamic proteomic polymorphism alterations among samples from the different Cs compartments during maturation. More than 1,900 protein bands were analyzed using density-weighted ZUNIX similarity equations and clustering methods, revealing integral polymorphism similarities of 57.4% between the premature and mature stromata and 42.8% between the premature and mature caterpillar bodies. The across-compartment similarity was low, ranging from 10.0% to 18.4%. Consequently, each Cs compartment (i.e., the stroma and caterpillar body) formed a clustering clade, and the 2 clades formed a Cs cluster. The polymorphic similarities ranged from 0.51% to 1.04% between Hs and the Cs compartments and were 2.8- to 4.8-fold higher (1.92%–4.34%) between Ph and the Cs compartments. The Hs and Ph mycelial samples formed isolated clades outside of the Cs cluster. Conclusion Proteomic polymorphisms in the caterpillar body and stroma of Cs change dynamically during maturation. The proteomic polymorphisms in Hs and Ph differ from those in Cs, suggesting the presence of multiple Cs-associated fungi and multiple Ophiocordyceps sinensis genotypes with altered differential protein expression in the Cs compartments

  4. Tamoxifen induces pleiotrophic changes in mammary stroma resulting in extracellular matrix that suppresses transformed phenotypes

    PubMed Central

    Hattar, Rhonda; Maller, Ori; McDaniel, Shauntae; Hansen, Kirk C; Hedman, Karla J; Lyons, Traci R; Lucia, Scott; Wilson, R Storey; Schedin, Pepper

    2009-01-01

    Introduction The functional unit of the mammary gland has been defined as the epithelial cell plus its microenvironment, a hypothesis that predicts changes in epithelial cell function will be accompanied by concurrent changes in mammary stroma. To test this hypothesis, the question was addressed of whether mammary stroma is functionally altered by the anti-oestrogen drug tamoxifen. Methods Forty female rats at 70 days of age were randomised to two groups of 20 and treated with 1.0 mg/kg tamoxifen or vehicle subcutaneously daily for 30 days, followed by a three-day wash out period. Mammary tissue was harvested and effects of tamoxifen on mammary epithelium and stroma determined. Results As expected, tamoxifen suppressed mammary alveolar development and mammary epithelial cell proliferation. Primary mammary fibroblasts isolated from tamoxifen-treated rats displayed a three-fold decrease in motility and incorporated less fibronectin in their substratum in comparison to control fibroblasts; attributes indicative of fibroblast quiescence. Immunohistochemistry analysis of CD68, a macrophage lysosomal marker, demonstrated a reduction in macrophage infiltration in mammary glands of tamoxifen-treated rats. Proteomic analyses by mass spectrometry identified several extracellular matrix (ECM) proteins with expression levels with tamoxifen treatment that were validated by Western blot. Mammary tissue from tamoxifen-treated rats had decreased fibronectin and increased collagen 1 levels. Further, ECM proteolysis was reduced in tamoxifen-treated rats as detected by reductions in fibronectin, laminin 1, laminin 5 and collagen 1 cleavage fragments. Consistent with suppression in ECM proteolysis with tamoxifen treatment, matrix metalloproteinase-2 levels and activity were decreased. Biochemically extracted mammary ECM from tamoxifen-treated rats suppressed in vitro macrophage motility, which was rescued by the addition of proteolysed collagen or fibronectin. Mammary ECM from

  5. Biliary cystadenoma with mesenchymal stroma: Report of a case and review of the literature

    PubMed Central

    Manouras, Andreas; Markogiannakis, Haridimos; Lagoudianakis, Emmanuel; Katergiannakis, Vangelogiannis

    2006-01-01

    Biliary cystadenomas are rare, cystic neoplasms of the biliary ductal system that usually occur in middle-aged women. They cannot be safely differentiated from cystadenocarcinomas before operation and should always be considered for resection. Cystadenomas have a strong tendency to recur, particularly following incomplete excision, and a potential of malignant transformation. Therefore, complete resection is the therapy of choice and thorough histopathologic evaluation is imperative. A case of benign biliary cystadenoma with mesenchymal stroma is presented along with a review of the relative literature addressing the clinical presentation, histology, histogenesis, differential diagnosis, imaging features, treatment and prognosis of this interesting and rare entity. PMID:17009411

  6. Multiphoton imaging to identify grana, stroma thylakoid, and starch inside an intact leaf

    PubMed Central

    2014-01-01

    Background Grana and starch are major functional structures for photosynthesis and energy storage of plant, respectively. Both exhibit highly ordered molecular structures and appear as micrometer-sized granules inside chloroplasts. In order to distinguish grana and starch, we used multiphoton microscopy, with simultaneous acquisition of two-photon fluorescence (2PF) and second harmonic generation (SHG) signals. SHG is sensitive to crystallized structures while 2PF selectively reveals the distribution of chlorophyll. Result Three distinct microstructures with different contrasts were observed, i.e. “SHG dominates”, “2PF dominates”, and “SHG collocated with 2PF”. It is known that starch and grana both emit SHG due to their highly crystallized structures, and no autofluorescence is emitted from starch, so the “SHG dominates” contrast should correspond to starch. The contrast of “SHG collocated with 2PF” is assigned to be grana, which exhibit crystallized structure with autofluorescent chlorophyll. The “2PF dominates” contrast should correspond to stroma thylakoid, which is a non-packed membrane structure with chrolophyll. The contrast assignment is further supported by fluorescence lifetime measurement. Conclusion We have demonstrated a straightforward and noninvasive method to identify the distribution of grana and starch within an intact leaf. By merging the 2PF and SHG images, grana, starch and stroma thylakoid can be visually distinguished. This approach can be extended to the observation of 3D grana distribution and their dynamics in living plants. PMID:24969621

  7. Distinct subpopulations of FOXD1 stroma-derived cells regulate renal erythropoietin.

    PubMed

    Kobayashi, Hanako; Liu, Qingdu; Binns, Thomas C; Urrutia, Andres A; Davidoff, Olena; Kapitsinou, Pinelopi P; Pfaff, Andrew S; Olauson, Hannes; Wernerson, Annika; Fogo, Agnes B; Fong, Guo-Hua; Gross, Kenneth W; Haase, Volker H

    2016-05-01

    Renal peritubular interstitial fibroblast-like cells are critical for adult erythropoiesis, as they are the main source of erythropoietin (EPO). Hypoxia-inducible factor 2 (HIF-2) controls EPO synthesis in the kidney and liver and is regulated by prolyl-4-hydroxylase domain (PHD) dioxygenases PHD1, PHD2, and PHD3, which function as cellular oxygen sensors. Renal interstitial cells with EPO-producing capacity are poorly characterized, and the role of the PHD/HIF-2 axis in renal EPO-producing cell (REPC) plasticity is unclear. Here we targeted the PHD/HIF-2/EPO axis in FOXD1 stroma-derived renal interstitial cells and examined the role of individual PHDs in REPC pool size regulation and renal EPO output. Renal interstitial cells with EPO-producing capacity were entirely derived from FOXD1-expressing stroma, and Phd2 inactivation alone induced renal Epo in a limited number of renal interstitial cells. EPO induction was submaximal, as hypoxia or pharmacologic PHD inhibition further increased the REPC fraction among Phd2-/- renal interstitial cells. Moreover, Phd1 and Phd3 were differentially expressed in renal interstitium, and heterozygous deficiency for Phd1 and Phd3 increased REPC numbers in Phd2-/- mice. We propose that FOXD1 lineage renal interstitial cells consist of distinct subpopulations that differ in their responsiveness to Phd2 inactivation and thus regulation of HIF-2 activity and EPO production under hypoxia or conditions of pharmacologic or genetic PHD inactivation. PMID:27088801

  8. On Orbit Osteobiology Experiments: from "STROMA" to "MDS" -from in vitro to in vivo

    NASA Astrophysics Data System (ADS)

    Liu, Yi; Cancedda, Ranieri

    Spaceflight causes profound changes in the skeleton, in particular, in the weight-loading bones. Uncoupling of bone remodeling equilibrium between bone formation and resorption is con-sidered responsible for the microgravity-induced bone loss. These changes result in weak-ened and brittle bones prone to fracture on re-entry and in accelerated osteoporosis, making bone deterioration a major problem obstructing the prospects of long-duration manned space flight. Osteoblasts (bone forming cells) and osteocytes (bone resorption cells) are known to be mechano-sensors. Short-exposure of osteoblasts to simulated microgravity ensnarled cell adhe-sion and cytoskeleton. Also osteoblast precursors such as bone marrow stroma cells (BMSC) were shown to be sensitive to mechanical loading. We performed a series of STROMA space-flight experiments by culturing BMSC or co-culturing osteoblasts and osteoclast precursors in automated bioreactors on orbit. Genechip analysis revealed an inhibition of cell proliferation and an unexpected activation of nervous system development genes by spaceflight. To unravel effects of microgravity on genes governing bone mass, transgenic mice with a higher bone mass were flown to orbit inside the Mice Drawer System (MDS) payload. The MDS experiment was launched inside Shuttle Discovery in STS-128 on August 28 2009 at 23:58 EST, and returned to earth by Shuttle Atlantis in STS129 on November 27 2009 at 9:47 EST, marking it as the first long duration animal experiment on the International Space Station (ISS).

  9. Stroma provides an intestinal stem cell niche in the absence of epithelial Wnts.

    PubMed

    Kabiri, Zahra; Greicius, Gediminas; Madan, Babita; Biechele, Steffen; Zhong, Zhendong; Zaribafzadeh, Hamed; Edison; Aliyev, Jamal; Wu, Yonghui; Bunte, Ralph; Williams, Bart O; Rossant, Janet; Virshup, David M

    2014-06-01

    Wnt/β-catenin signaling supports intestinal homeostasis by regulating proliferation in the crypt. Multiple Wnts are expressed in Paneth cells as well as other intestinal epithelial and stromal cells. Ex vivo, Wnts secreted by Paneth cells can support intestinal stem cells when Wnt signaling is enhanced with supplemental R-Spondin 1 (RSPO1). However, in vivo, the source of Wnts in the stem cell niche is less clear. Genetic ablation of Porcn, an endoplasmic reticulum resident O-acyltransferase that is essential for the secretion and activity of all vertebrate Wnts, confirmed the role of intestinal epithelial Wnts in ex vivo culture. Unexpectedly, mice lacking epithelial Wnt activity (Porcn(Del)/Villin-Cre mice) had normal intestinal proliferation and differentiation, as well as successful regeneration after radiation injury, indicating that epithelial Wnts are dispensable for these processes. Consistent with a key role for stroma in the crypt niche, intestinal stromal cells endogenously expressing Wnts and Rspo3 support the growth of Porcn(Del) organoids ex vivo without RSPO1 supplementation. Conversely, increasing pharmacologic PORCN inhibition, affecting both stroma and epithelium, reduced Lgr5 intestinal stem cells, inhibited recovery from radiation injury, and at the highest dose fully blocked intestinal proliferation. We conclude that epithelial Wnts are dispensable and that stromal production of Wnts can fully support normal murine intestinal homeostasis. PMID:24821987

  10. Regulation of dendritic-cell differentiation by bone marrow stroma via different Notch ligands

    PubMed Central

    Cheng, Pingyan; Nefedova, Yulia; Corzo, Cesar A.; Gabrilovich, Dmitry I.

    2007-01-01

    Notch is a major factor mediating interaction between hematopoietic progenitor cells (HPCs) and bone marrow stroma (BMS). However its contribution to dendritic cell (DC) differentiation is controversial. We found that main Notch ligands Delta-1 and Jagged-1 had the opposite effect on DC differentiation. Delta-1 promoted generation of fully differentiated DCs, whereas Jagged-1 stimulated accumulation of DC precursors but prevented their transition to terminally differentiated DCs. BMS expressed a substantially higher level of Jagged-1 than Delta-1. Just the opposite expression pattern was observed in spleen stroma (SS). The BMS effect on DC differentiation was similar to that of Jagged-1, whereas the effect of SS was similar to the effect of Delta-1. Down-regulation of Jagged-1 in BMS substantially increased DC differentiation. Experiments in vivo with adoptive transfer of DC precursors further supported the different roles of BMS and SS in DC development. Jagged-1 and Delta-1 equally activated CBF-1/RBPJκ transcription factor, which is a major Notch target. However, they produced a different pattern of activation of Notch target gene Hes1. Overexpression of Hes1 resulted in increased DC differentiation from HPCs. Thus, this study not only revealed the different role of Notch ligands in DC differentiation but also may provide a new insight into regulation of DC differentiation by BMS. PMID:16973960

  11. Gene Expression Analysis of In Vitro Cocultures to Study Interactions between Breast Epithelium and Stroma

    PubMed Central

    Casbas-Hernandez, Patricia; Fleming, Jodie M.; Troester, Melissa A.

    2011-01-01

    The interactions between breast epithelium and stroma are fundamental to normal tissue homeostasis and for tumor initiation and progression. Gene expression studies of in vitro coculture models demonstrate that in vitro models have relevance for tumor progression in vivo. For example, stromal gene expression has been shown to vary in association with tumor subtype in vivo, and analogous in vitro cocultures recapitulate subtype-specific biological interactions. Cocultures can be used to study cancer cell interactions with specific stromal components (e.g., immune cells, fibroblasts, endothelium) and different representative cell lines (e.g., cancer-associated versus normal-associated fibroblasts versus established, immortalized fibroblasts) can help elucidate the role of stromal variation in tumor phenotypes. Gene expression data can also be combined with cell-based assays to identify cellular phenotypes associated with gene expression changes. Coculture systems are manipulable systems that can yield important insights about cell-cell interactions and the cellular phenotypes that occur as tumor and stroma co-evolve. PMID:22203785

  12. Impact of Stroma on the Growth, Microcirculation, and Metabolism of Experimental Prostate Tumors

    PubMed Central

    Zechmann, Christian M; Woenne, Eva C; Brix, Gunnar; Radzwill, Nicole; Ilg, Martin; Bachert, Peter; Peschke, Peter; Kirsch, Stefan; Kauczor, Hans-Ulrich; Delorme, Stefan; Semmler, Wolfhard; Kiessling, Fabian

    2007-01-01

    Abstract In prostate cancers (PCa), the formation of malignant stroma may substantially influence tumor phenotype and aggressiveness. Thus, the impact of the orthotopic and subcutaneous implantations of hormone-sensitive (H), hormone-insensitive (HI), and anaplastic (AT1) Dunning PCa in rats on growth, microcirculation, and metabolism was investigated. For this purpose, dynamic contrast-enhanced magnetic resonance imaging and 1H magnetic resonance spectroscopy ([1H]MRS) were applied in combination with histology. Consistent observations revealed that orthotopic H tumors grew significantly slower compared to subcutaneous ones, whereas the growth of HI and AT1 tumors was comparable at both locations. Histologic analysis indicated that glandular differentiation and a close interaction of tumor cells and smooth muscle cells (SMC) were associated with slow tumor growth. Furthermore, there was a significantly lower SMC density in subcutaneous H tumors than in orthotopic H tumors. Perfusion was observed to be significantly lower in orthotopic H tumors than in subcutaneous H tumors. Regional blood volume and permeability-surface area product showed no significant differences between tumor models and their implantation sites. Differences in growth between subcutaneous and orthotopic H tumors can be attributed to tumor-stroma interaction and perfusion. Here, SMC, may stabilize glandular structures and contribute to the maintenance of differentiated phenotype. PMID:17325744

  13. Type IV collagen is a tumour stroma-derived biomarker for pancreas cancer

    PubMed Central

    Öhlund, D; Lundin, C; Ardnor, B; Öman, M; Naredi, P; Sund, M

    2009-01-01

    Background: Pancreas cancer is a dreaded disease with high mortality, despite progress in surgical and oncological treatments in recent years. The field is hampered by a lack of good prognostic and predictive tumour biomarkers to be used during follow-up of patients. Methods: The circulating level of type IV collagen was measured by ELISA in pancreas cancer patients and controls. The expression pattern of type IV collagen in normal pancreas, pancreas cancer tissue and in pancreas cancer cell lines was studied by immunofluorescence and Western blot techniques. Results: Patients with pancreas cancer have significantly increased circulating levels of type IV collagen. In pancreas cancer tissue high levels of type IV collagen expression was found in close proximity to cancer cells in the tumour stroma. Furthermore, pancreas cancer cells were found to produce and secrete type IV collagen in vitro, which in part can explain the high type IV collagen expression observed in pancreas cancer tissue, and the increased circulating levels in pancreas cancer patients. Of clinical importance, our results show that the circulating level of type IV collagen after surgery is strongly related to prognosis in patients treated for pancreas cancer by pancreatico-duodenectomy with curative intent. Persisting high levels of circulating type IV collagen after surgery indicates a quick relapse in disease and poor survival. Conclusion: Our results most importantly show that stroma related substances can be evaluated as potential cancer biomarkers, and thereby underline the importance of the tumour microenvironment also in this context. PMID:19491897

  14. Distinct subpopulations of FOXD1 stroma-derived cells regulate renal erythropoietin

    PubMed Central

    Liu, Qingdu; Binns, Thomas C.; Davidoff, Olena; Kapitsinou, Pinelopi P.; Pfaff, Andrew S.; Olauson, Hannes; Fogo, Agnes B.; Fong, Guo-Hua; Gross, Kenneth W.

    2016-01-01

    Renal peritubular interstitial fibroblast-like cells are critical for adult erythropoiesis, as they are the main source of erythropoietin (EPO). Hypoxia-inducible factor 2 (HIF-2) controls EPO synthesis in the kidney and liver and is regulated by prolyl-4-hydroxylase domain (PHD) dioxygenases PHD1, PHD2, and PHD3, which function as cellular oxygen sensors. Renal interstitial cells with EPO-producing capacity are poorly characterized, and the role of the PHD/HIF-2 axis in renal EPO-producing cell (REPC) plasticity is unclear. Here we targeted the PHD/HIF-2/EPO axis in FOXD1 stroma-derived renal interstitial cells and examined the role of individual PHDs in REPC pool size regulation and renal EPO output. Renal interstitial cells with EPO-producing capacity were entirely derived from FOXD1-expressing stroma, and Phd2 inactivation alone induced renal Epo in a limited number of renal interstitial cells. EPO induction was submaximal, as hypoxia or pharmacologic PHD inhibition further increased the REPC fraction among Phd2–/– renal interstitial cells. Moreover, Phd1 and Phd3 were differentially expressed in renal interstitium, and heterozygous deficiency for Phd1 and Phd3 increased REPC numbers in Phd2–/– mice. We propose that FOXD1 lineage renal interstitial cells consist of distinct subpopulations that differ in their responsiveness to Phd2 inactivation and thus regulation of HIF-2 activity and EPO production under hypoxia or conditions of pharmacologic or genetic PHD inactivation. PMID:27088801

  15. The identification of trans-associations between prostate cancer GWAS SNPs and RNA expression differences in tumor-adjacent stroma

    PubMed Central

    Chen, Xin; McClelland, Michael; Jia, Zhenyu; Rahmatpanah, Farah B.; Sawyers, Anne; Trent, Jeffrey; Duggan, David; Mercola, Dan

    2015-01-01

    Here we tested the hypothesis that SNPs associated with prostate cancer risk, might differentially affect RNA expression in prostate cancer stroma. The most significant 35 SNP loci were selected from Genome Wide Association (GWA) studies of ~40,000 patients. We also selected 4030 transcripts previously associated with prostate cancer diagnosis and prognosis. eQTL analysis was carried out by a modified BAYES method to analyze the associations between the risk variants and expressed transcripts jointly in a single model. We observed 47 significant associations between eight risk variants and the expression patterns of 46 genes. This is the first study to identify associations between multiple SNPs and multiple in trans gene expression differences in cancer stroma. Potentially, a combination of SNPs and associated expression differences in prostate stroma may increase the power of risk assessment for individuals, and for cancer progression. PMID:25638161

  16. Giant cell tumor of the pancreas arising in the ovarian-like stroma of a mucinous cystadenocarcinoma.

    PubMed

    Bergman, S; Medeiros, L J; Radr, T; Mangham, D C; Lewandrowski, K B

    1995-08-01

    We describe a malignant mucinous cystic neoplasm of the pancreas with ovarian-like stroma within which an osteoclast-like giant cell rich tumor arose. This rare tumor had a unique immunohistochemical profile with the giant cells staining for vimentin, leukocyte common antigen, and the monocyte/macrophage marker CD68, whereas the mucinous epithelium stained for epithelial membrane antigen and cytokeratin. The immunohistochemical findings are consistent with two lines of differentiation, one epithelial and the other suggesting mesenchymal differentiation of the giant cell tumor with an immunophenotype similar to giant cell tumor of bone. The coexistence of these two rare tumors suggests that they are histogenetically related. The findings of a giant cell tumor arising in the ovarian stroma indicates that the stroma of mucinous tumors is not always an innocuous component of the tumor. PMID:7594774

  17. Systems Analysis of a Mouse Xenograft Model Reveals Annexin A1 as a Regulator of Gene Expression in Tumor Stroma

    PubMed Central

    Yi, Ming

    2012-01-01

    Annexin A1 is a multi functional molecule which is involved in inflammation, innate and adaptive immune systems, tumor progression and metastasis. We have previously showed the impaired tumor growth, metastasis, angiogenesis and wound healing in annexin A1 knockout mice. While tumor is a piece of heterogeneous mass including not only malignant tumor cells but also the stroma, the importance of the tumor stroma for tumor progression and metastasis is becoming increasingly clear. The tumor stroma is comprised by various components including extracellular matrix and non-malignant cells in the tumor, such as endothelial cells, fibroblasts, immune cells, inflammatory cells. Based on our previous finding of pro-angiogenic functions for annexin A1 in vascular endothelial cell sprouting, wound healing, tumor growth and metastasis, and the previously known properties for annexin A1 in immune cells and inflammation, this study hypothesized that annexin A1 is a key functional player in tumor development, linking the various components in tumor stroma by its actions in endothelial cells and immune cells. Using systems analysis programs commercially available, this paper further compared the gene expression between tumors from annexin A1 wild type mice and annexin A1 knockout mice and found a list of genes that significantly changed in the tumor stroma that lacked annexin A1. This revealed annexin A1 to be an effective regulator in tumor stroma and suggested a mechanism that annexin A1 affects tumor development and metastasis through interaction with the various components in the microenvironment surrounding the tumor cells. PMID:23077482

  18. Assessing the temporal stability of spatial patterns of soil apparent electrical conductivity using geophysical methods

    NASA Astrophysics Data System (ADS)

    De Caires, Sunshine A.; Wuddivira, Mark N.; Bekele, Isaac

    2014-10-01

    Cocoa remains in the same field for decades, resulting in plantations dominated with aging trees growing on variable and depleted soils. We determined the spatio-temporal variability of key soil properties in a (5.81 ha) field from the International Cocoa Genebank, Trinidad using geophysical methods. Multi-year (2008-2009) measurements of apparent electrical conductivity at 0-0.75 m (shallow) and 0.75-1.5 m (deep) were conducted. Apparent electrical conductivity at deep and shallow gave the strongest linear correlation with clay-silt content (R = 0.67 and R = 0.78, respectively) and soil solution electrical conductivity (R = 0.76 and R = 0.60, respectively). Spearman rank correlation coefficients ranged between 0.89-0.97 and 0.81- 0.95 for apparent electrical conductivity at deep and shallow, respectively, signifying a strong linear dependence between measurement days. Thus, in the humid tropics, cocoa fields with thick organic litter layer and relatively dense understory cover, experience minimal fluctuations in transient properties of soil water and temperature at the topsoil resulting in similarly stable apparent electrical conductivity at shallow and deep. Therefore, apparent electrical conductivity at shallow, which covers the depth where cocoa feeder roots concentrate, can be used as a fertility indicator and to develop soil zones for efficient application of inputs and management of cocoa fields.

  19. Ectopic micronodular thymoma with lymphoid stroma in the cervical region: a rare case associated with Langerhans cells proliferation

    PubMed Central

    Yu, Min; Meng, Yuan; Xu, Bin; Zhao, Lin; Zhang, Qingfu

    2016-01-01

    Micronodular thymoma (MNT) with lymphoid stroma is a rare thymic epithelial neoplasm with the characteristics of multiple nodules separated by abundant lymphoid stroma. MNTs mainly arise in the anterior mediastinum and thymus, while ectopic MNTs are extremely rarely seen. Here, we report an ectopic MNT that occurred in the neck of a 62-year-old woman. There were also scattered eosinophilic granulocytes and S100+/CD1a+ Langerhans cells within the tumor. This case provides a better understanding of such rare, poorly understood cases. PMID:27486334

  20. Deep source gas

    SciTech Connect

    Not Available

    1985-02-01

    Three separate emplacement concepts could explain the occurrence of gas at extreme depths: abiogenesis (a primordial, nonbiologic origin source); subducted, organic-origin gas (involving the deep, tectonic subduction emplacement of hydrocarbon-generating ocean sediments); and deep sedimentary basin gas (the more conventional emplacement of sedimentary rocks by deep downwarping of the Earth's crust). Of these concepts, Deep Source Gas research focuses on the subducted, organic-origin concept. The purpose of Deep Source Gas research is to verify natural gas arising from depths in excess of 30,000 feet, to relate these occurrences to conceptual models, to define the limits of target areas, to quantify the resource, and to determine the significance of the gas to the nation's reserves. The research emphasizes an Earth science study (geology, geochemistry, and geophysics) of the Cordilleran Geologic Province of western North America. This area is considered a prospective source largely because of known and suspected plate tectonic structures and their youthful emplacement, which increase the likelihood of a timely entrapment of deep-source generated hydrocarbons. Detailed geochemical studies indicate that the deep-source-gas generating capacity of the Aleutian Trench area of southern Alaska is high. Furthermore, geophysical studies show that an apparent fossil subduction zone exists in western Washington. This zone appears to have very thick sedimentary rock units, the existence of which will be evaluated through a more detailed seismic study and possibly through drilling activities. Structural observations made in the northern Brooks Range and central Alaskan Range indicate that overthrusting and compressional features may serve as large-scale target areas for deep source gas generation and occurrence. 12 figures, 2 tables.

  1. Virtual microdissection identifies distinct tumor- and stroma-specific subtypes of pancreatic ductal adenocarcinoma

    PubMed Central

    Moffitt, Richard A.; Marayati, Raoud; Flate, Elizabeth L.; Volmar, Keith E.; Loeza, S. Gabriela Herrera; Hoadley, Katherine A.; Rashid, Naim U.; Williams, Lindsay A.; Eaton, Samuel C.; Chung, Alexander H.; Smyla, Jadwiga K.; Anderson, Judy M.; Kim, Hong Jin; Bentrem, David J.; Talamonti, Mark S.; Iacobuzio-Donahue, Christine A.; Hollingsworth, Michael A.; Yeh, Jen Jen

    2016-01-01

    Pancreatic ductal adenocarcinoma (PDAC) remains a lethal disease with a 5-year survival of 4%. A key hallmark of PDAC is extensive stromal involvement, which makes capturing precise tumor-specific molecular information difficult. Here, we have overcome this problem by applying blind source separation to a diverse collection of PDAC gene expression microarray data, which includes primary, metastatic, and normal samples. By digitally separating tumor, stroma, and normal gene expression, we have identified and validated two tumor-specific subtypes including a “basal-like” subtype which has worse outcome, and is molecularly similar to basal tumors in bladder and breast cancer. Furthermore, we define “normal” and “activated” stromal subtypes which are independently prognostic. Our results provide new insight into the molecular composition of PDAC which may be used to tailor therapies or provide decision support in a clinical setting where the choice and timing of therapies is critical. PMID:26343385

  2. Thermal Transitions of Fibrillar Collagen Unveiled by Second-Harmonic Generation Microscopy of Corneal Stroma

    PubMed Central

    Matteini, Paolo; Cicchi, Riccardo; Ratto, Fulvio; Kapsokalyvas, Dimitrios; Rossi, Francesca; de Angelis, Marella; Pavone, Francesco S.; Pini, Roberto

    2012-01-01

    The thermal transitions of fibrillar collagen are investigated with second-harmonic generation polarization anisotropy microscopy. Second-harmonic generation images and polarization anisotropy profiles of corneal stroma heated in the 35–80°C range are analyzed by means of a theoretical model that is suitable to probe principal intramolecular and interfibrillar parameters of immediate physiological interest. Our results depict the tissue modification with temperature as the interplay of three destructuration stages at different hierarchical levels of collagen assembly including its tertiary structure and interfibrillar alignment, thus supporting and extending previous findings. This method holds the promise of a quantitative inspection of fundamental biophysical and biochemical processes and may find future applications in real-time and postsurgical functional imaging of collagen-rich tissues subjected to thermal treatments. PMID:22995490

  3. Sclerotic fibroma (storiform collagenoma)-like stroma in a fibroadenoma of axillary accessory breast tissue.

    PubMed

    Val-Bernal, José Fernando; González-Vela, María Carmen; De Grado, Mauricio; Garijo, María Francisca

    2012-08-01

    Accessory breast tissue is a subcutaneous remnant persisting after normal embryological development of the breast. It occurs most frequently in the axilla. Fibroadenomas in axillary breast tissue are rare. We report the case of a 29-year-old female patient who presented a fibroadenoma arising in the accessory breast tissue of the right axillary fossa. The neoplasm showed foci of sclerotic fibroma-like stroma. The patient had no signs of Cowden's syndrome. To the best of our knowledge, a lesion of this kind has not been previously reported. This stromal change suggests an uncommon involutional phase of the fibroadenoma with production of sclerotic and hypocellular collagen. The lesion should be differentiated from extraneural perineuroma, from the changes in fibroadenomas in Cowden's syndrome, from sclerosing lobular hyperplasia (fibroadenomatoid mastopathy) and from pseudoangiomatous stromal hyperplasia. PMID:22804110

  4. Separation and identification of the light harvesting proteins contained in grana and stroma thylakoid membrane fractions.

    PubMed

    Timperio, Anna Maria; Huber, Christian G; Zolla, Lello

    2004-06-18

    This paper presents the results of a study performed to develop a rapid and straightforward method to resolve and simultaneously identify the light-harvesting proteins of photosystem I (LHCI) and photosystem II (LHCII) present in the grana and stroma of the thylakoid membranes of higher plants. These hydrophobic proteins are embedded in the phospholipid membrane, and their extraction usually requires detergent and time consuming manipulations that may introduce artifacts. The method presented here makes use of digitonin, a detergent which causes rapid (within less than 3 min) cleavage of the thylakoid membrane into two subfractions: appressed (grana) and non-appressed (stroma) membranes, the former enriched in photosystem II and the latter containing mainly photosystem I. From these two fractions identification of the protein components was performed by separating them by reversed-phase high-performance liquid chromatography (RP-HPLC) and determining the intact molecular mass by electrospray ionization mass spectrometry (ESI-MS). By this strategy the ion suppression during ESI-MS that normally occurs in the presence of membrane phospholipids was avoided, since RP-HPLC removed most phospholipids from the analytes. Consequently, high quality mass spectra were extracted from the reconstructed ion chromatograms. The specific cleavage of thylakoid membranes by digitonin, as well as the rapid identification and quantification of the antenna composition of the two complexes facilitate future studies of the lateral migration of the chlorophyll-protein complexes along thylakoid membranes, which is well known to be induced by high intensity light or other environmental stresses. Such investigations could not be performed by sodium dodecylsulfate-polyacrylamide gel electrophoresis because of insufficient resolution of the proteins having molecular masses between 22,000 and 25,000. PMID:15248427

  5. A Native-Like Corneal Construct Using Donor Corneal Stroma for Tissue Engineering

    PubMed Central

    Lin, Jing; Yoon, Kyung-Chul; Zhang, Lili; Su, Zhitao; Lu, Rong; Ma, Ping; De Paiva, Cintia S.; Pflugfelder, Stephen C.; Li, De-Quan

    2012-01-01

    Tissue engineering holds great promise for corneal transplantation to treat blinding diseases. This study was to explore the use of natural corneal stroma as an optimal substrate to construct a native like corneal equivalent. Human corneal epithelium was cultivated from donor limbal explants on corneal stromal discs prepared by FDA approved Horizon Epikeratome system. The morphology, phenotype, regenerative capacity and transplantation potential were evaluated by hematoxylin eosin and immunofluorescent staining, a wound healing model, and the xeno-transplantation of the corneal constructs to nude mice. An optically transparent and stratified epithelium was rapidly generated on donor corneal stromal substrate and displayed native-like morphology and structure. The cells were polygonal in the basal layer and became flattened in superficial layers. The epithelium displayed a phenotype similar to human corneal epithelium in vivo. The differentiation markers, keratin 3, involucrin and connexin 43, were expressed in full or superficial layers. Interestingly, certain basal cells were immunopositive to antibodies against limbal stem/progenitor cell markers ABCG2 and p63, which are usually negative in corneal epithelium in vivo. It suggests that this bioengineered corneal epithelium shared some characteristics of human limbal epithelium in vivo. This engineered epithelium was able to regenerate in 4 days following from a 4mm-diameter wound created by a filter paper soaked with 1 N NaOH. This corneal construct survived well after xeno-transplantation to the back of a nude mouse. The transplanted epithelium remained multilayer and became thicker with a phenotype similar to human corneal epithelium. Our findings demonstrate that natural corneal stroma is an optimal substrate for tissue bioengineering, and a native-like corneal construct has been created with epithelium containing limbal stem cells. This construct may have great potential for clinical use in corneal

  6. Bidirectional Signaling of Mammary Epithelium and Stroma: Implications for Breast Cancer—Preventive Actions of Dietary Factors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mammary gland is composed of two major cellular compartments: a highly dynamic epithelium that undergoes cycles of proliferation, differentiation, and apoptosis in response to local and endocrine signals and the underlying stroma comprised of fibroblasts, endothelial cells, and adipocytes that c...

  7. Membrane-to-Nucleus Signals and Epigenetic Mechanisms for Myofibroblastic Activation and Desmoplastic Stroma: Potential Therapeutic Targets for Liver Metastasis?

    PubMed Central

    Kang, Ningling; Shah, Vijay H.; Urrutia, Raul

    2015-01-01

    Cancer associated fibroblasts (CAFs), the most abundant cells in the tumor microenvironment (TME), are a key source of extracellular matrix (ECM) that constitutes the desmoplastic stroma. Through remodeling of the reactive tumor stroma and paracrine actions, CAFs regulate cancer initiation, progression, and metastasis, as well as tumor resistance to therapies. The CAFs found in stroma-rich primary hepatocellular carcinomas (HCCs) and liver metastases of primary cancers of other organs predominantly originate from hepatic stellate cells (HSTCs), which are pericytes associated with hepatic sinusoids. During tumor invasion, HSTCs transdifferentiate into myofibroblasts in response to paracrine signals emanating from either tumor cells or a heterogenous cell population within the hepatic tumor microenvironment. Mechanistically, HSTC-to-myofibroblast transdifferentiation, also known as, HSTC activation, requires cell surface receptor activation, intracellular signal transduction, gene transcription and epigenetic signals, which combined ultimately modulate distinct gene expression profiles that give rise to and maintain a new phenotype. The current review, defines a paradigm that explains how HSTCs are activated into CAFs to promote liver metastasis. Furthermore, focus on the most relevant intracellular signaling networks and epigenetic mechanisms that control HSTC activation is provided. Finally, we discuss the feasibility of targeting CAF/activated HSTCs, in isolation or in conjunction with targeting cancer cells, which constitutes a promising and viable therapeutic approach for the treatment of primary stroma-rich liver cancers and liver metastasis. PMID:25548101

  8. On the Bartnik mass of apparent horizons

    NASA Astrophysics Data System (ADS)

    Mantoulidis, Christos; Schoen, Richard

    2015-10-01

    In this paper we characterize the intrinsic geometry of apparent horizons (outermost marginally outer trapped surfaces) in asymptotically flat spacetimes; that is, the Riemannian metrics on the two sphere which can arise. Furthermore we determine the minimal ADM mass of a spacetime containing such an apparent horizon. The results are conveniently formulated in terms of the quasi-local mass introduced by Bartnik (1989 Phys. Rev. Lett. 62 2346-8). The Hawking mass provides a lower bound for Bartnik’s quasilocal mass on apparent horizons by way of Penrose’s conjecture on time symmetric slices, proven in 1997 by Huisken and Ilmanen (2001 J. Differ. Geom. 59 353-437) and in full generality in 1999 by Bray (2001 J. Differ. Geom. 59 177-267). We compute Bartnik’s mass for all non-degenerate apparent horizons and show that it coincides with the Hawking mass. As a corollary we disprove a conjecture due to Gibbons in the spirit of Thorne’s hoop conjecture (Gibbons 2009 arXiv:0903.1580), and construct a new large class of examples of apparent horizons with the integral of the negative part of the Gauss curvature arbitrarily large.

  9. High temperature strain gage apparent strain compensation

    NASA Technical Reports Server (NTRS)

    Holmes, Harlan K.; Moore, T. C., Sr.

    1992-01-01

    Once an installed strain gage is connected to a strain indicating device and the instrument is balanced, a subsequent change in temperature of the gage installation will generally produce a resistance change in the gage. This purely temperature-induced resistance will be registered by the indicating device as a strain and is referred to as 'apparent strain' to distinguish it from strain due to applied stress. One desirable technique for apparent strain compensation is to employ two identical gages with identical mounting procedures which are connected with a 'half bridge' configuration where gages see the same thermal environment but only one experiences a mechanical strain input. Their connection in adjacent arms of the bridge will then balance the thermally induced apparent strains and, in principle, only the mechanical strain remains. Two approaches that implement this technique are discussed.

  10. Apparent subdiffusion inherent to single particle tracking.

    PubMed Central

    Martin, Douglas S; Forstner, Martin B; Käs, Josef A

    2002-01-01

    Subdiffusion and its causes in both in vivo and in vitro lipid membranes have become the focus of recent research. We report apparent subdiffusion, observed via single particle tracking (SPT), in a homogeneous system that only allows normal diffusion (a DMPC monolayer in the fluid state). The apparent subdiffusion arises from slight errors in finding the actual particle position due to noise inherent in all experimental SPT systems. A model is presented that corrects this artifact, and predicts the time scales after which the effect becomes negligible. The techniques and results presented in this paper should be of use in all SPT experiments studying normal and anomalous diffusion. PMID:12324428

  11. Apparent subdiffusion inherent to single particle tracking.

    PubMed

    Martin, Douglas S; Forstner, Martin B; Käs, Josef A

    2002-10-01

    Subdiffusion and its causes in both in vivo and in vitro lipid membranes have become the focus of recent research. We report apparent subdiffusion, observed via single particle tracking (SPT), in a homogeneous system that only allows normal diffusion (a DMPC monolayer in the fluid state). The apparent subdiffusion arises from slight errors in finding the actual particle position due to noise inherent in all experimental SPT systems. A model is presented that corrects this artifact, and predicts the time scales after which the effect becomes negligible. The techniques and results presented in this paper should be of use in all SPT experiments studying normal and anomalous diffusion. PMID:12324428

  12. An Apparently Classical Case Report of Sturge-Weber Syndrome.

    PubMed

    Giannantoni, Nadia Mariagrazia; Della Marca, Giacomo; Vollono, Catello

    2015-10-01

    Sturge-Weber syndrome is a rare, sporadic, congenital neurocutaneous syndrome, likely due to abnormal development of the cephalic microvasculature. Symptoms and signs depend on the extent and location of the venous dysplasia. We describe a case of a 33-year-old woman presenting with drug-resistant epilepsy, chronic headache, and recurring nonepileptic seizures. Computed tomography and magnetic resonance imaging scans showed severe frontoparietal right hemisphere atrophy, prevalent right frontoparietal leptomeningeal enhancement, circumscribed angioma of the left rolandic sulcus, and prominent deep venous system. We report an apparently classical Sturge-Weber syndrome and hypothesize a shared pathophysiologic mechanism for clinical symptoms. We speculate that all the main symptoms observed in our patient could be the expression of a functional imbalance between the atrophic right hemisphere and the hyperexcitable left cortex. PMID:25392004

  13. SU-E-J-248: Contributions of Tumor and Stroma Phenotyping in Computer-Aided Diagnosis

    SciTech Connect

    Li, H; Lan, L; Sennett, C; Giger, M

    2015-06-15

    Purpose: To gain insight into the role of parenchyma stroma in the characterization of breast tumors by incorporating computerized mammographic parenchyma assessment into breast CADx in the task of distinguishing between malignant and benign lesions. Methods: This study was performed on 182 biopsy-proven breast mass lesions, including 76 benign and 106 malignant lesions. For each full-field digital mammogram (FFDM) case, our quantitative imaging analysis was performed on both the tumor and a region-of-interest (ROI) from the normal contralateral breast. The lesion characterization includes automatic lesion segmentation and feature extraction. Radiographic texture analysis (RTA) was applied on the normal ROIs to assess the mammographic parenchymal patterns of these contralateral normal breasts. Classification performance of both individual computer extracted features and the output from a Bayesian artificial neural network (BANN) were evaluated with a leave-one-lesion-out method using receiver operating characteristic (ROC) analysis with area under the curve (AUC) as the figure of merit. Results: Lesion characterization included computer-extracted phenotypes of spiculation, size, shape, and margin. For parenchymal pattern characterization, five texture features were selected, including power law beta, contrast, and edge gradient. Merging of these computer-selected features using BANN classifiers yielded AUC values of 0.79 (SE=0.03) and 0.67 (SE=0.04) in the task of distinguishing between malignant and benign lesions using only tumor phenotypes and texture features from the contralateral breasts, respectively. Incorporation of tumor phenotypes with parenchyma texture features into the BANN yielded improved classification performance with an AUC value of 0.83 (SE=0.03) in the task of differentiating malignant from benign lesions. Conclusion: Combining computerized tumor and parenchyma phenotyping was found to significantly improve breast cancer diagnostic accuracy

  14. Immune Dysfunction Associated with Abnormal Bone Marrow-Derived Mesenchymal Stroma Cells in Senescence Accelerated Mice

    PubMed Central

    Li, Ming; Guo, Kequan; Adachi, Yasushi; Ikehara, Susumu

    2016-01-01

    Senescence accelerated mice (SAM) are a group of mice that show aging-related diseases, and SAM prone 10 (SAMP10) show spontaneous brain atrophy and defects in learning and memory. Our previous report showed that the thymus and the percentage of T lymphocytes are abnormal in the SAMP10, but it was unclear whether the bone marrow-derived mesenchymal stroma cells (BMMSCs) were abnormal, and whether they played an important role in regenerative medicine. We thus compared BMMSCs from SAMP10 and their control, SAM-resistant (SAMR1), in terms of cell cycle, oxidative stress, and the expression of PI3K and mitogen-activated protein kinase (MAPK). Our cell cycle analysis showed that cell cycle arrest occurred in the G0/G1 phase in the SAMP10. We also found increased reactive oxygen stress and decreased PI3K and MAPK on the BMMSCs. These results suggested the BMMSCs were abnormal in SAMP10, and that this might be related to the immune system dysfunction in these mice. PMID:26840301

  15. Mapping the Extracellular and Membrane Proteome Associated with the Vasculature and the Stroma in the Embryo*

    PubMed Central

    Soulet, Fabienne; Kilarski, Witold W.; Roux-Dalvai, Florence; Herbert, John M. J.; Sacewicz, Izabela; Mouton-Barbosa, Emmanuelle; Bicknell, Roy; Lalor, Patricia; Monsarrat, Bernard; Bikfalvi, Andreas

    2013-01-01

    In order to map the extracellular or membrane proteome associated with the vasculature and the stroma in an embryonic organism in vivo, we developed a biotinylation technique for chicken embryo and combined it with mass spectrometry and bioinformatic analysis. We also applied this procedure to implanted tumors growing on the chorioallantoic membrane or after the induction of granulation tissue. Membrane and extracellular matrix proteins were the most abundant components identified. Relative quantitative analysis revealed differential protein expression patterns in several tissues. Through a bioinformatic approach, we determined endothelial cell protein expression signatures, which allowed us to identify several proteins not yet reported to be associated with endothelial cells or the vasculature. This is the first study reported so far that applies in vivo biotinylation, in combination with robust label-free quantitative proteomics approaches and bioinformatic analysis, to an embryonic organism. It also provides the first description of the vascular and matrix proteome of the embryo that might constitute the starting point for further developments. PMID:23674615

  16. Therapeutic applications of mesenchymal stroma cells in pediatric diseases: current aspects and future perspectives.

    PubMed

    Habib, Hamid S; Halawa, Taher F; Atta, Hazem M

    2011-11-01

    Mesenchymal stem cells or stroma cells (MSCs) were recently proven to play various therapeutic roles when used in clinical trials to control various inflammatory, neoplastic and immunologic diseases in children. Clinical trials show some promising results, particularly in diseases where conventional therapy is still ineffective. However, experimental studies sometimes show conflicting results. This review aims to assess the current therapeutic role of MSCs in the control of several pediatric diseases and elaborate on their future applications by reviewing published studies. A review of published studies on this subject based on Pubmed and Medical Subject Heading databases, with search for all relevant articles focusing on results of clinical trials to evaluate the clinical applications of MSCs. The review includes documentation of positive as well as negative applications of MSCs focused on pediatric diseases. MSCs have important immunosuppressive and antifibrotic effects that need to be employed to help patients with diseases for which no conventional management has proven to be effective. They may be also be used as an adjuvant to conventional therapeutic modalities to consolidate recovery. This review sheds light on the significance of the use of MSCs for the treatment of various pediatric diseases and focuses on promising applications. Most of the reported studies agree about the favorable use of MSCs in various diseases; however, more clinical trials, involving larger numbers of patients, need to be conducted in order to refine the outcome of the therapeutic methods and establish standardized protocols. PMID:22037754

  17. Resolving Cancer-Stroma Interfacial Signaling and Interventions with Micropatterned Tumor-Stromal Assays

    PubMed Central

    Shen, Keyue; Luk, Samantha; Hicks, Daniel F; Elman, Jessica S; Bohr, Stefan; Iwamoto, Yoshiko; Murray, Ryan; Pena, Kristen; Wang, Fangjing; Seker, Erkin; Weissleder, Ralph; Yarmush, Martin L; Toner, Mehmet; Sgroi, Dennis; Parekkadan, Biju

    2014-01-01

    Tumor-stromal interactions are a determining factor in cancer progression. In vivo, the interaction interface is associated with spatially-resolved distributions of cancer and stromal phenotypes. Here, we establish a micropatterned tumor-stromal assay (μTSA) with laser capture microdissection to control the location of co-cultured cells and analyze bulk and interfacial tumor-stromal signaling in driving cancer progression. μTSA reveals a spatial distribution of phenotypes in concordance with human estrogen receptor-positive (ER+) breast cancer samples, and heterogeneous drug activity relative to the tumor-stroma interface. Specifically, an unknown mechanism of reversine is shown in targeting tumor-stromal interfacial interactions using ER+ MCF-7 breast cancer and bone marrow-derived stromal cells. Reversine suppresses MCF-7 tumor growth and bone metastasis in vivo by reducing tumor stromalization including collagen deposition and recruitment of activated stromal cells. This study advocates μTSA as a platform for studying tumor microenvironmental interactions and cancer field effects with applications in drug discovery and development. PMID:25489927

  18. Clinicopathological implications of vascular endothelial growth factor 165b expression in oral squamous cell carcinoma stroma.

    PubMed

    Nagasaki, Masahiro; Kondo, Seiji; Mukudai, Yoshiki; Kamatani, Takaaki; Akizuki, Ayako; Yaso, Atsushi; Shimane, Toshikazu; Shirota, Tatsuo

    2016-07-01

    Vascular endothelial growth factor (VEGF) is one of the most important angiogenic factors. VEGF165b was recently isolated as the anti-angiogenic VEGF splice variant. In the present study, we examined the association between VEGF165b expression and clinicopathological characteristics in order to determine how VEGF165b produced from oral squamous cell carcinoma (OSCC) affects the stromal cell biological activity. We examined the relationships between the expressions of both VEGF isoforms in normal human dermal fibroblasts (NHDFs) and OSCC cell lines (HSC2, 3, 4 and SAS). Our analyses indicated that both the mRNA and protein expression levels of VEGF165b in the HSC2 and SAS cells were higher than those in the NHDFs. VEGF165b did not promote cell growth or invasive capabilities, but it induced the cell adhesive capabilities to ECM. Although strong expression of the VEGF165 isoforms in tumor cells of OSCC tissues was observed, there was no significant difference in the VEGF165b expression level among the various degrees of malignancy. OSCC cells secrete VEGF165b into the stroma, and this factor may contribute to the process of anti-angiogenesis by inhibiting gelatinase-expressing cells and activating cell adhesive capabilities to ECM, such as that of fibroblasts surrounding tumor cells. PMID:27221145

  19. Scatter factor influences the formation of prostate epithelial cell colonies on bone marrow stroma in vitro.

    PubMed

    Lang, S H; Clarke, N W; George, N J; Testa, N G

    1999-06-01

    Prostate cancer metastases form selectively in the bone marrow. Previously we demonstrated motility was important for the formation of primary prostatic epithelial cell colonies in bone marrow stroma (BMS) co-culture. In this study we looked at the influence of motility factors on the colony formation of epithelial cells derived from benign (bPEC) or malignant (mPEC) prostate tissue. After 7 days co-culture we found that anti-scatter factor consistently inhibited prostate epithelial cell colony formation on BMS (7/7 mPEC and 4/7 bPEC samples showed significant inhibition). Antibodies against bFGF and 5T4 did not significantly affect colony formation. Addition of fibroblast conditioned media (derived from benign prostates) to co-cultures stimulated the colony formation of bPEC (170%) and mPEC (252%). This stimulation was eliminated by depletion of SF from the conditioned media. Immunohistochemical staining found c-Met expression in 5/6 bPEC cultures and 7/9 mPEC cultures. When grown in BMS co-culture expression of c-Met was positive in 3/6 bPEC and 2/7 mPEC samples. In conclusion, scatter factor influences the in vitro formation of prostate epithelial cell colonies on BMS co-culture. PMID:10545020

  20. Concurrent Gastric Adenocarcinoma of Fundic Gland Type and Carcinoma with Lymphoid Stroma: A Rare Case Report

    PubMed Central

    Cha, Hee Jeong; Kim, Kyungbin; Kim, Misung; Choi, Hyejeong; Kim, Young Min; Suh, Jae Hee

    2016-01-01

    Both gastric adenocarcinoma of fundic gland type (ADC-FG) and carcinoma with lymphoid stroma (lymphoepithelioma-like carcinoma, LELC) are relatively rare. Epstein-Barr virus (EBV) has been implicated in the pathogenesis of LELC. However, the pathogenesis of ADC-FG, as well as the role of EBV in the carcinogenesis of LELC, remain unclear and under debate. The current study presents a case of concurrent ADC-FG and LELC in the stomach in a 69-year-old man. Total gastrectomy was performed, and two separate masses were identified. Upon histological and immunohistochemical examination, the mass located in the lower body was determined to be LELC and the mass in the upper body was diagnosed as ADC-FG. The lesions were characterized by different mucin phenotypes and EBV in situ results. In the lower-body mass, EBV in situ hybridization expression was diffusely strongly positive, but MUC2, MUC5AC, MUC6, and CD10 were all negative. On the other hand, in the upper-body mass, the results were positive for MUC6 but negative for MUC2, MUC5AC, CD10, and EBV by in situ hybridization. The remaining gastric tissue was unremarkable, and perigastric lymph node metastases were absent. Seven months after the gastrectomy, a postoperative computed tomography scan revealed no recurrence or metastasis. PMID:27462199

  1. Deep Earthquakes.

    ERIC Educational Resources Information Center

    Frohlich, Cliff

    1989-01-01

    Summarizes research to find the nature of deep earthquakes occurring hundreds of kilometers down in the earth's mantle. Describes further research problems in this area. Presents several illustrations and four references. (YP)

  2. Apparent extended body motions in depth

    NASA Technical Reports Server (NTRS)

    Hecht, Heiko; Proffitt, Dennis R.

    1991-01-01

    Five experiments were designed to investigate the influence of three-dimensional (3-D) orientation change on apparent motion. Projections of an orientation-specific 3-D object were sequentially flashed in different locations and at different orientations. Such an occurrence could be resolved by perceiving a rotational motion in depth around an axis external to the object. Consistent with this proposal, it was found that observers perceived curved paths in depth. Although the magnitude of perceived trajectory curvature often fell short of that required for rotational motions in depth (3-D circularity), judgments of the slant of the virtual plane on which apparent motions occurred were quite close to the predictions of a model that proposes circular paths in depth.

  3. Efficient Transduction of Corneal Stroma by Adeno-Associated Viral Serotype Vectors for Implications in Gene Therapy of Corneal Diseases.

    PubMed

    Lu, Yi; Ai, Jianzhong; Gessler, Dominic; Su, Qin; Tran, Karen; Zheng, Qiang; Xu, Xun; Gao, Guangping

    2016-08-01

    Corneal disease is one of the leading causes of blindness worldwide. Gene therapy is an attractive therapeutic strategy for corneal diseases, but currently underdeveloped. Recombinant adeno-associated viral (rAAV) vectors have emerged as a highly promising gene therapy platform. This study aims to identify rAAV vectors that can efficiently transduce corneal stroma for potential applications in studying pathophysiology of corneal diseases and therapeutic development. We characterized 14 rAAV serotypes expressing enhanced green fluorescent protein (EGFP), for cell specificity and transduction efficiency after either intrastromal injection or topical administration in mouse corneas in vivo. Our results show that intrastromal injections of rAAVrh.8, rAAVrh.10, rAAVrh.39, and rAAVrh.43 efficiently transduce mouse corneal stroma in vivo, and that topical administrations of rAAVrh.10 and rAAVrh.39 subsequent to epithelial scraping generate detectable transgene expression. In vivo imaging analysis revealed that transgene expression became detectable by 1 week postadministration, peaked at 2 weeks, and lasted for the duration of the study (i.e., 4 weeks). Both rAAVrh.10 and rAAVrh.39 transduced more than 50% of keratocytes, the major cell type in the corneal stroma, by intrastromal injection and 30% by topical administration. Histopathology indicated that rAAV transduction of cornea caused no morphological adverse effects. Overall, our findings suggest that some rAAV serotype vectors can efficiently transduce corneal stroma in vivo, constituting a potentially powerful and safe gene delivery platform for gene therapy of corneal diseases. PMID:27001051

  4. Ex vivo and in vivo modulatory effects of umbilical cord Wharton's jelly stem cells on human oral mucosa stroma substitutes.

    PubMed

    Alfonso-Rodríguez, C A; González-Andrades, E; Jaimes-Parra, B D; Fernández-Valadés, R; Campos, A; Sánchez-Quevedo, M C; Alaminos, M; Garzón, I

    2015-11-01

    Novel oral mucosa substitutes have been developed in the laboratory using human umbilical cord Wharton's jelly stem cells -HWJSC- as an alternative cell source. In the present work, we have generated human oral mucosa substitutes with oral mucosa keratinocytes and HWJSC to determine the influence of these cell sources on stromal differentiation. First, acellular and cellular stroma substitutes and bilayered oral mucosa substitutes with an epithelial layer consisting of oral mucosa keratinocytes -OM samples- or HWJSC -hOM- were generated. Then, tissues were analyzed by light and electron microscopy, histochemistry and immunohistochemistry to quantify all major extracellular matrix components after 1, 2 and 3 weeks of ex vivo development, and OM and hOM were also analyzed after in vivo grafting. The results showed that bioengineered oral mucosa stromas displayed an adequate fibrillar mesh. Synthesis of abundant collagen fibers was detected in OM and hOM after 3 weeks, and in vivo grafting resulted in an increased collagen synthesis. No elastic or reticular fibers were found. Glycoprotein synthesis was found at the epithelial-stromal layer when samples were grafted in vivo. Finally, proteoglycans, decorin, versican and aggrecan were strongly dependent on the in vivo environment and the presence of a well-structured epithelium on top. The use of HWJSC was associated to an increased synthesis of versican. These results confirm the usefulness of fibrin-agarose biomaterials for the generation of an efficient human oral mucosa stroma substitute and the importance of the in vivo environment and the epithelial-mesenchymal interaction for the adequate differentiation of the bioengineered stroma. PMID:25967581

  5. Amount of stroma is associated with mammographic density and stromal expression of oestrogen receptor in normal breast tissues.

    PubMed

    Gabrielson, Marike; Chiesa, Flaminia; Paulsson, Janna; Strell, Carina; Behmer, Catharina; Rönnow, Katarina; Czene, Kamila; Östman, Arne; Hall, Per

    2016-07-01

    Following female sex and age, mammographic density is considered one of the strongest risk factors for breast cancer. Despite the association between mammographic density and breast cancer risk, little is known about the underlying histology and biological basis of breast density. To better understand the mechanisms behind mammographic density we assessed morphology, proliferation and hormone receptor status in relation to mammographic density in breast tissues from healthy women. Tissues were obtained from 2012-2013 by ultrasound-guided core needle biopsy from 160 women as part of the Karma (Karolinska mammography project for risk prediction for breast cancer) project. Mammograms were collected through routine mammography screening and mammographic density was calculated using STRATUS. The histological composition, epithelial and stromal proliferation status and hormone receptor status were assessed through immunohistochemical staining. Higher mammographic density was significantly associated with a greater proportion of stromal and epithelial tissue and a lower proportion of adipose tissue. Epithelial expression levels of Ki-67, oestrogen receptor (ER) and progesterone receptor (PR) were not associated with mammographic density. Epithelial Ki-67 was associated with a greater proportion of epithelial tissue, and epithelial PR was associated with a greater proportion of stromal and a lower proportion of adipose tissue. Epithelial ER was not associated with any tissues. In contrast, expression of ER in the stroma was significantly associated with a greater proportion of stroma, and negatively associated with the amount of adipose tissue. High mammographic density is associated with higher amount of stroma and epithelium and less amount of fat, but is not associated with a change in epithelial proliferation or receptor status. Increased expressions of both epithelial PR and stromal ER are associated with a greater proportion of stroma, suggesting hormonal involvement

  6. Comment: An Apparent Controversy in Auroral Physics

    NASA Astrophysics Data System (ADS)

    Haerendel, Gerhard

    2007-03-01

    In his article ``A turning point in auroral physics,'' Bryant argued against what he called the `standard' theory of auroral acceleration, according to which the electrons ``gain their energy from static electric fields,'' and offered wave acceleration as an alternative. Because of the importance of the process, not only for the aurora borealis but also for other cosmic plasmas, a clarification of this apparent controversy seems to be in place.

  7. The Apparent Thermal Conductivity of Pozzolana Concrete

    NASA Astrophysics Data System (ADS)

    Bessenouci, M. Z.; Triki, N. E. Bibi; Khelladi, S.; Draoui, B.; Abene, A.

    The recent development of some lightweight construction materials, such as light concrete, can play an important role as an insulator, while maintaining sufficient levels of mechanical performance. The quality of insulation to provide depends on the climate, the exposure of the walls and also the materials used in the construction. The choice of a material to be used as an insulator, obviously, depends on its availability and its cost. This is a study of natural pozzolanas as basic components in building materials. It is intended to highlight their thermal advantage. It is economically advantageous to use pozzolana in substitution for a portion of the clinker as hydraulically active additions, as well as in compositions of lightweight concretes in the form of pozzolanic aggregate mixtures, which provide mechanical strengths that comply with current standards. A theoretical study is conducted on the apparent thermal conductivity of building materials, namely concrete containing pozzolana. Thermal modeling, apparent to that commonly used for porous materials, has been applied to pozzolana concrete. Experimental results on measurements of the apparent thermal conductivity of pozzolana concrete are reported in this study, using an approach that considers that concrete is composed of two solid ingredients, a binding matrix (hydrated cement paste) and all aggregates. A second comparative theoretical approach is used for the case where concrete consists of a solid phase and a fluid phase (air).

  8. Apparent Solar Tornado-Like Prominences

    NASA Astrophysics Data System (ADS)

    Panasenco, Olga; Martin, Sara F.; Velli, Marco

    2014-02-01

    Recent high-resolution observations from the Solar Dynamics Observatory (SDO) have reawakened interest in the old and fascinating phenomenon of solar tornado-like prominences. This class of prominences was first introduced by Pettit ( Astrophys. J. 76, 9, 1932), who studied them over many years. Observations of tornado prominences similar to the ones seen by SDO had already been documented by Secchi ( Le Soleil, 1877). High-resolution and high-cadence multiwavelength data obtained by SDO reveal that the tornado-like appearance of these prominences is mainly an illusion due to projection effects. We discuss two different cases where prominences on the limb might appear to have a tornado-like behavior. One case of apparent vortical motions in prominence spines and barbs arises from the (mostly) 2D counterstreaming plasma motion along the prominence spine and barbs together with oscillations along individual threads. The other case of apparent rotational motion is observed in a prominence cavity and results from the 3D plasma motion along the writhed magnetic fields inside and along the prominence cavity as seen projected on the limb. Thus, the "tornado" impression results either from counterstreaming and oscillations or from the projection on the plane of the sky of plasma motion along magnetic-field lines, rather than from a true vortical motion around an (apparent) vertical or horizontal axis. We discuss the link between tornado-like prominences, filament barbs, and photospheric vortices at their base.

  9. Combined cytotoxic and anti-invasive properties of redox-active nanoparticles in tumor-stroma interactions.

    PubMed

    Alili, Lirija; Sack, Maren; Karakoti, Ajay S; Teuber, Sarah; Puschmann, Katharina; Hirst, Suzanne M; Reilly, Christopher M; Zanger, Klaus; Stahl, Wilhelm; Das, Soumen; Seal, Sudipta; Brenneisen, Peter

    2011-04-01

    Tumor-stroma interaction plays an important role in tumor progression. Myofibroblasts, pivotal for tumor progression, populate the microecosystem of reactive stroma. The formation of myofibroblasts is mediated by tumor derived transforming growth factor β1 (TGFβ1) which initiates a reactive oxygen species cell type dependent expression of alpha-smooth muscle actin, a biomarker for myofibroblastic cells. Myofibroblasts express and secrete proinvasive factors significantly increasing the invasive capacity of tumor cells via paracrine mechanisms. Although antioxidants prevent myofibroblast formation, the same antioxidants increase the aggressive behavior of the tumor cells. In this study, the question was addressed of whether redox-active polymer-coated cerium oxide nanoparticles (CNP, nanoceria) affect myofibroblast formation, cell toxicity, and tumor invasion. Herein, nanoceria downregulate both the expression of alpha-smooth muscle actin positive myofibroblastic cells and the invasion of tumor cells. Furthermore, concentrations of nanoceria being non-toxic for normal (stromal) cells show a cytotoxic effect on squamous tumor cells. The treatment with redox-active CNP may form the basis for protection of stromal cells from the dominating influence of tumor cells in tumor-stroma interaction, thus being a promising strategy for chemoprevention of tumor invasion. PMID:21269688

  10. Apparent horizons in binary black hole spacetimes

    NASA Astrophysics Data System (ADS)

    Shoemaker, Deirdre Marie

    Over the last decade, advances in computing technology and numerical techniques have lead to the possible theoretical prediction of astrophysically relevant waveforms in numerical simulations. With the building of gravitational wave detectors such as the Laser Interferometric Gravitational-Wave Observatory, we stand at the epoch that will usher in the first experimental study of strong field general relativity. One candidate source for ground based detection of gravitational waveforms, the orbit and merger of two black holes, is of great interest to the relativity community. The binary black hole problem is the two-body problem in general relativity. It is a stringent dynamical test of the theory. The problem involves the evolution of the Einstein equation, a complex system of non-linear, dynamic, elliptic-hyperbolic equations intractable in closed form. Numerical relativists are now developing the technology to evolve the Einstein equation using numerical simulations. The generation of these numerical I codes is a ``theoretical laboratory'' designed to study strong field phenomena in general relativity. This dissertation reports the successful development and application of the first multiple apparent horizon tracker applied to the generic binary black hole problem. I have developed a method that combines a level set of surfaces with a curvature flow method. This method, which I call the level flow method, locates the surfaces of any apparent horizons in the spacetime. The surface location then is used to remove the singularities from the computational domain in the evolution code. I establish the following set of criteria desired in an apparent horizon tracker: (1)The robustness of the tracker due to its lack of dependence on small changes to the initial guess; (2)The generality of the tracker in its applicability to generic spacetimes including multiple back hole spacetimes; and (3)The efficiency of the tracker algorithm in CPU time. I demonstrate the apparent

  11. JNK1 stress signaling is hyper-activated in high breast density and the tumor stroma

    PubMed Central

    Lisanti, Michael P; Tsirigos, Aristotelis; Pavlides, Stephanos; Reeves, Kimberley Jayne; Peiris-Pagès, Maria; Chadwick, Amy L; Sanchez-Alvarez, Rosa; Lamb, Rebecca; Howell, Anthony; Martinez-Outschoorn, Ubaldo E; Sotgia, Federica

    2014-01-01

    myofibroblasts and macrophages, to create and maintain a fibrotic and inflammatory microenvironment. Finally, comparisons between the HD fibroblast gene signature and breast cancer tumor stroma revealed that JNK1 stress signaling is the single most significant biological process that is shared between these 2 data sets (with P values between 5.40E-09 and 1.02E-14), and is specifically associated with tumor recurrence. These results implicate “stromal JNK1 signaling” in the pathogenesis of human breast cancers and the transition to malignancy. Augmented TGF-β signaling also emerged as a common feature linking high breast density with tumor stroma and breast cancer recurrence (P = 5.23E-05). Similarities between the HD fibroblast gene signature, wound healing, and the cancer-associated fibroblast phenotype were also noted. Thus, this unbiased informatics analysis of high breast density provides a novel framework for additional experimental exploration and new hypothesis-driven breast cancer research, with a focus on cancer prevention and personalized medicine. PMID:24434780

  12. Multikinase inhibitor regorafenib inhibits the growth and metastasis of colon cancer with abundant stroma.

    PubMed

    Takigawa, Hidehiko; Kitadai, Yasuhiko; Shinagawa, Kei; Yuge, Ryo; Higashi, Yukihito; Tanaka, Shinji; Yasui, Wataru; Chayama, Kazuaki

    2016-05-01

    Interaction between tumor cells and stromal cells plays an important role in the growth and metastasis of colon cancer. We previously found that carcinoma-associated fibroblasts (CAFs) expressed platelet-derived growth factor receptor-β (PDGFR-β) and that PDGFR targeted therapy using imatinib or nilotinib inhibited stromal reaction. Bone marrow-derived mesenchymal stem cells (MSCs) migrate to tumor stroma and differentiate into CAFs. A novel oral multikinase inhibitor regorafenib inhibits receptor tyrosine kinases expressed on stromal cells (vascular endothelial growth factor receptor 1-3, TIE2, PDGFR-β, and fibroblast growth factors) and tumor cells (c-KIT, RET, and BRAF). These molecules are involved in tumor growth, angiogenesis, lymphangiogenesis, and stromal activation. Therefore, we examined whether regorafenib impaired the tumor-promoting effect of CAFs/MSCs. KM12SM human colon cancer cells alone or KM12SM cells with MSCs were transplanted into the cecal wall of nude mice. Co-implantation of KM12SM cells with MSCs into the cecal wall of nude mice produced tumors with abundant stromal component and promoted tumor growth and lymph node metastasis. Single treatment with regorafenib inhibited tumor growth and metastasis by inhibiting both tumor cells and stromal reaction. This tumor-inhibitory effect of regorafenib was more obvious in tumors developed by co-implanting KM12SM cells with MSCs. Our data suggested that targeting of the tumor microenvironment with regorafenib affected tumor cell-MSC interaction, which in turn inhibited the growth and metastasis of colon cancer. PMID:26865419

  13. EDC/NHS cross-linked collagen foams as scaffolds for artificial corneal stroma.

    PubMed

    Vrana, N E; Builles, N; Kocak, H; Gulay, P; Justin, V; Malbouyres, M; Ruggiero, F; Damour, O; Hasirci, V

    2007-01-01

    In this study, a highly porous collagen-based biodegradable scaffold was developed as an alternative to synthetic, non-degradable corneal implants. The developed method involved lyophilization and subsequent stabilization through N-ethyl-N'-[3-dimethylaminopropyl] carbodiimide/N-hydroxy succinimide (EDC/NHS) cross-linking to yield longer lasting, porous scaffolds with a thickness similar to that of native cornea (500 microm). For collagen-based scaffolds, cross-linking is essential; however, it has direct effects on physical characteristics crucial for optimum cell behavior. Hence, the effect of cross-linking was studied by examining the influence of cross-linking on pore size distribution, bulk porosity and average pore size. After seeding the foam with human corneal keratocytes, cell proliferation, cell penetration into the scaffold and ECM production within the scaffold were studied. After a month of culture microscopical and immunohistochemical examinations showed that the foam structure did not undergo any significant loss of integrity, and the human corneal keratocytes populated the scaffold with cells migrating both longitudinally and laterally, and secreted some of the main constituents of the corneal ECM, namely collagen types I, V and VI. The foams had a layer of lower porosity (skin layer) both at the top and the bottom. Foams had an optimal porosity (93.6%), average pore size (67.7 microm), and chemistry for cell attachment and proliferation. They also had a sufficiently rapid degradation rate (73.6+/-1.1% in 4 weeks) and could be produced at a thickness close to that of the natural corneal stroma. Cells were seeded at the top surface of the foams and their numbers there was higher than the rest, basically due to the presence of the skin layer. This is considered to be an advantage when epithelial cells need to be seeded for the construction of hemi or full thickness cornea. PMID:17988518

  14. Detecting thermal phase transitions in corneal stroma by fluorescence micro-imaging analysis

    NASA Astrophysics Data System (ADS)

    Matteini, P.; Rossi, F.; Ratto, F.; Bruno, I.; Nesi, P.; Pini, R.

    2008-02-01

    Thermal modifications induced in corneal stroma were investigated by the use of fluorescence microscopy. Freshly extracted porcine corneas were immersed for 5 minutes in a water bath at temperatures in the 35-90°C range and stored in formalin. The samples were then sliced in 200-μm-thick transversal sections and analyzed under a stereomicroscope to assess corneal shrinkage. Fluorescence images of the thermally treated corneal samples were acquired using a slow-scan cooled CCD camera, after staining the slices with Indocyanine Green (ICG) fluorescent dye which allowed to detect fluorescence signal from the whole tissue. All measurements were performed using an inverted epifluorescence microscope equipped with a mercury lamp. The thermally-induced modifications to the corneal specimens were evaluated by studying the grey level distribution in the fluorescence images. For each acquired image, Discrete Fourier Transform (DFT) and entropy analyses were performed. The spatial distribution of DFT absolute value indicated the spatial orientation of the lamellar planes, while entropy was used to study the image texture, correlated to the stromal structural transitions. As a result, it was possible to indicate a temperature threshold value (62°C) for high thermal damage, resulting in a disorganization of the lamellar planes and in full agreement with the measured temperature for corneal shrinkage onset. Analysis of the image entropy evidenced five strong modifications in stromal architecture at temperatures of ~45°C, 53°C, 57°C, 66°C, 75°C. The proposed procedure proved to be an effective micro-imaging method capable of detecting subtle changes in corneal tissue subjected to thermal treatment.

  15. Human Ovarian Cancer Stroma Contains Luteinized Theca Cells Harboring Tumor Suppressor Gene GT198 Mutations*

    PubMed Central

    Peng, Min; Zhang, Hao; Jaafar, Lahcen; Risinger, John I.; Huang, Shuang; Mivechi, Nahid F.; Ko, Lan

    2013-01-01

    Ovarian cancer is a highly lethal gynecological cancer, and its causes remain to be understood. Using a recently identified tumor suppressor gene, GT198 (PSMC3IP), as a unique marker, we searched for the identity of GT198 mutant cells in ovarian cancer. GT198 has germ line mutations in familial and early onset breast and ovarian cancers and recurrent somatic mutations in sporadic fallopian tube cancers. GT198 protein has been shown as a steroid hormone receptor coregulator and also as a crucial factor in DNA repair. In this study, using GT198 as a marker for microdissection, we find that ovarian tumor stromal cells harboring GT198 mutations are present in various types of ovarian cancer including high and low grade serous, endometrioid, mucinous, clear cell, and granulosa cell carcinomas and in precursor lesions such as inclusion cysts. The mutant stromal cells consist of a luteinized theca cell lineage at various differentiation stages including CD133+, CD44+, and CD34+ cells, although the vast majority of them are differentiated overexpressing steroidogenic enzyme CYP17, a theca cell-specific marker. In addition, wild type GT198 suppresses whereas mutant GT198 protein stimulates CYP17 expression. The chromatin-bound GT198 on the human CYP17 promoter is decreased by overexpressing mutant GT198 protein, implicating the loss of wild type suppression in mutant cells. Together, our results suggest that GT198 mutant luteinized theca cells overexpressing CYP17 are common in ovarian cancer stroma. Because first hit cancer gene mutations would specifically mark cancer-inducing cells, the identification of mutant luteinized theca cells may add crucial evidence in understanding the cause of human ovarian cancer. PMID:24097974

  16. Loss of caveolin-1 and gain of MCT4 expression in the tumor stroma

    PubMed Central

    Martins, Diana; Beça, Francisco F; Sousa, Bárbara; Baltazar, Fátima; Paredes, Joana; Schmitt, Fernando

    2013-01-01

    The progression from in situ to invasive breast carcinoma is still an event poorly understood. However, it has been suggested that interactions between the neoplastic cells and the tumor microenvironment may play an important role in this process. Thus, the determination of differential tumor-stromal metabolic interactions could be an important step in invasiveness. The expression of stromal Caveolin-1 (Cav-1) has already been implicated in the progression from ductal carcinoma in situ (DCIS) to invasive ductal carcinoma (IDC). Additionally, stromal Cav-1 expression has been associated with the expression of stromal monocarboxylate transporter 4 (MCT4) in invasive breast cancer. However, the role of stromal MCT4 in invasiveness has never been explored, neither the association between Cav-1 and MCT4 in the transition from breast DCIS to IDC. Therefore, our aim was to investigate in a series of breast cancer samples including matched in situ and invasive components, if there was a relationship between stromal Cav-1 and MCT4 in the progression from in situ to invasive carcinoma. We found loss of stromal Cav-1 in the progression to IDC in 75% of the cases. In contrast, MCT4 stromal expression was acquired in 87% of the IDCs. Interestingly, a concomitant loss of Cav-1 and gain of MCT4 was observed in the stroma of 75% of the cases, when matched in situ and invasive carcinomas were compared. These results suggest that alterations in Cav-1 and MCT4 may thus mark a critical point in the progression from in situ to invasive breast cancer. PMID:23907124

  17. Porphyromonas gingivalis within Placental Villous Mesenchyme and Umbilical Cord Stroma Is Associated with Adverse Pregnancy Outcome

    PubMed Central

    Vanterpool, Sizzle F.; Been, Jasper V.; Houben, Michiel L.; Nikkels, Peter G. J.; De Krijger, Ronald R.; Zimmermann, Luc J. I.; Kramer, Boris W.; Progulske-Fox, Ann; Reyes, Leticia

    2016-01-01

    Intrauterine presence of Porphyromonas gingivalis (Pg), a common oral pathobiont, is implicated in preterm birth. Our aim was to determine if the location of Pg within placental and/or umbilical cord sections was associated with a specific delivery diagnosis at preterm delivery (histologic chorioamnionitis, chorioamnionitis with funisitis, preeclampsia, and preeclampsia with HELLP-syndrome, small for gestational age). The prevalence and location of Pg within archived placental and umbilical cord specimens from preterm (25 to 32 weeks gestation) and term control cohorts were evaluated by immunofluorescent histology. Detection of Pg was performed blinded to pregnancy characteristics. Multivariate analyses were performed to evaluate independent effects of gestational age, being small for gestational age, specific preterm delivery diagnosis, antenatal steroids, and delivery mode, on the odds of having Pg in the preterm tissue. Within the preterm cohort, 49 of 97 (51%) placentas and 40 of 97 (41%) umbilical cord specimens were positive for Pg. Pg within the placenta was significantly associated with shorter gestation lengths (OR 0.63 (95%CI: 0.48–0.85; p = 0.002) per week) and delivery via caesarean section (OR 4.02 (95%CI: 1.15–14.04; p = 0.03), but not with histological chorioamnionitis or preeclampsia. However, the presence of Pg in the umbilical cord was significantly associated with preeclampsia: OR 6.73 (95%CI: 1.31–36.67; p = 0.02). In the term cohort, 2 of 35 (6%) placentas and no umbilical cord term specimens were positive for Pg. The location of Pg within the placenta was different between preterm and term groups in that Pg within the villous mesenchyme was only detected in the preterm cohort, whereas Pg associated with syncytiotrophoblasts was found in both preterm and term placentas. Taken together, our results suggest that the presence of Pg within the villous stroma or umbilical cord may be an important determinant in Pg-associated adverse pregnancy

  18. Six stroma-based RNA markers diagnostic for prostate cancer in European-Americans validated at the RNA and protein levels in patients in China

    PubMed Central

    Zhu, Jianguo; Pan, Cong; Jiang, Jun; Deng, Mingsen; Gao, Hengjun; Men, Bozhao; McClelland, Michael; Mercola, Dan; Zhong, Wei-De; Jia, Zhenyu

    2015-01-01

    We previously analyzed human prostate tissue containing stroma near to tumor and from cancer-negative tissues of volunteers. Over 100 candidate gene expression differences were identified and used to develop a classifier that could detect nearby tumor with an accuracy of 97% (sensitivity = 98% and specificity = 88%) based on 364 independent test cases from primarily European American cases. These stroma-based gene signatures have the potential to identify cancer patients among those with negative biopsies. In this study, we used prostate tissues from Chinese cases to validate six of these markers (CAV1, COL4A2, HSPB1, ITGB3, MAP1A and MCAM). In validation by real-time PCR, four genes (COL4A2, HSPB1, ITGB3, and MAP1A) demonstrated significantly lower expression in tumor-adjacent stroma compared to normal stroma (p value ≤ 0.05). Next, we tested whether these expression differences could be extended to the protein level. In IHC assays, all six selected proteins showed lower expression in tumor-adjacent stroma compared to the normal stroma, of which COL4A2, HSPB1 and ITGB3 showed significant differences (p value ≤ 0.05). These results suggest that biomarkers for diagnosing prostate cancer based on tumor microenvironment may be applicable across multiple racial groups. PMID:26158290

  19. Six stroma-based RNA markers diagnostic for prostate cancer in European-Americans validated at the RNA and protein levels in patients in China.

    PubMed

    Zhu, Jianguo; Pan, Cong; Jiang, Jun; Deng, Mingsen; Gao, Hengjun; Men, Bozhao; McClelland, Michael; Mercola, Dan; Zhong, Wei-D; Jia, Zhenyu

    2015-06-30

    We previously analyzed human prostate tissue containing stroma near to tumor and from cancer-negative tissues of volunteers. Over 100 candidate gene expression differences were identified and used to develop a classifier that could detect nearby tumor with an accuracy of 97% (sensitivity = 98% and specificity = 88%) based on 364 independent test cases from primarily European American cases. These stroma-based gene signatures have the potential to identify cancer patients among those with negative biopsies. In this study, we used prostate tissues from Chinese cases to validate six of these markers (CAV1, COL4A2, HSPB1, ITGB3, MAP1A and MCAM). In validation by real-time PCR, four genes (COL4A2, HSPB1, ITGB3, and MAP1A) demonstrated significantly lower expression in tumor-adjacent stroma compared to normal stroma (p value ≤ 0.05). Next, we tested whether these expression differences could be extended to the protein level. In IHC assays, all six selected proteins showed lower expression in tumor-adjacent stroma compared to the normal stroma, of which COL4A2, HSPB1 and ITGB3 showed significant differences (p value ≤ 0.05). These results suggest that biomarkers for diagnosing prostate cancer based on tumor microenvironment may be applicable across multiple racial groups. PMID:26158290

  20. Apparent magnitude of earthshine: a simple calculation

    NASA Astrophysics Data System (ADS)

    Agrawal, Dulli Chandra

    2016-05-01

    The Sun illuminates both the Moon and the Earth with practically the same luminous fluxes which are in turn reflected by them. The Moon provides a dim light to the Earth whereas the Earth illuminates the Moon with somewhat brighter light which can be seen from the Earth and is called earthshine. As the amount of light reflected from the Earth depends on part of the Earth and the cloud cover, the strength of earthshine varies throughout the year. The measure of the earthshine light is luminance, which is defined in photometry as the total luminous flux of light hitting or passing through a surface. The expression for the earthshine light in terms of the apparent magnitude has been derived for the first time and evaluated for two extreme cases; firstly, when the Sun’s rays are reflected by the water of the oceans and secondly when the reflector is either thick clouds or snow. The corresponding values are -1.30 and -3.69, respectively. The earthshine value -3.22 reported by Jackson lies within these apparent magnitudes. This paper will motivate the students and teachers of physics to look for the illuminated Moon by earthlight during the waning or waxing crescent phase of the Moon and to reproduce the expressions derived here by making use of the inverse-square law of radiation, Planck’s expression for the power in electromagnetic radiation, photopic spectral luminous efficiency function and expression for the apparent magnitude of a body in terms of luminous fluxes.

  1. Premature Ventricular Complexes in Apparently Normal Hearts.

    PubMed

    Luebbert, Jeffrey; Auberson, Denise; Marchlinski, Francis

    2016-09-01

    Premature ventricular complexes (PVCs) are consistently associated with worse prognosis and higher morbidity and mortality. This article reviews PVCs and their presentation in patients with an apparently normal heart. Patients with PVCs may be completely asymptomatic, whereas others may note severely disabling symptoms. Cardiomyopathy may occur with frequent PVCs. Diagnostic work-up is directed at obtaining 12-lead ECG to characterize QRS morphology, Holter monitor to assess frequency, and echo and advanced imaging to assess for early cardiomyopathy and exclude structural heart disease. Options for management include watchful waiting, medical therapy, or catheter ablation. Malignant variants of PVCs may induce ventricular fibrillation even in a normal heart. PMID:27521085

  2. Osteosarcoma With Apparent Ewing Sarcoma Gene Rearrangement.

    PubMed

    Mathias, Melissa D; Chou, Alexander J; Meyers, Paul; Shukla, Neerav; Hameed, Meera; Agaram, Narasimhan; Wang, Lu; Berger, Michael F; Walsh, Michael; Kentsis, Alex

    2016-07-01

    Poorly differentiated round cell sarcomas present diagnostic challenges because of their variable morphology and lack of specific immunophenotypic markers. We present a case of a 15-year-old female with a tibial tumor that exhibited features of Ewing-like sarcoma, including apparent rearrangement of the EWSR1 gene. Hybridization capture-based next-generation DNA sequencing showed evidence of complex genomic rearrangements, absence of known pathogenic Ewing-like chromosome translocations, and deletions RB1, PTCH1, and ATRX, supporting the diagnosis of osteosarcoma. This illustrates the potential of clinical genomic profiling to improve diagnosis and enable specifically targeted therapies for cancers with complex pathologies. PMID:27352193

  3. Deep learning

    NASA Astrophysics Data System (ADS)

    Lecun, Yann; Bengio, Yoshua; Hinton, Geoffrey

    2015-05-01

    Deep learning allows computational models that are composed of multiple processing layers to learn representations of data with multiple levels of abstraction. These methods have dramatically improved the state-of-the-art in speech recognition, visual object recognition, object detection and many other domains such as drug discovery and genomics. Deep learning discovers intricate structure in large data sets by using the backpropagation algorithm to indicate how a machine should change its internal parameters that are used to compute the representation in each layer from the representation in the previous layer. Deep convolutional nets have brought about breakthroughs in processing images, video, speech and audio, whereas recurrent nets have shone light on sequential data such as text and speech.

  4. Deep learning.

    PubMed

    LeCun, Yann; Bengio, Yoshua; Hinton, Geoffrey

    2015-05-28

    Deep learning allows computational models that are composed of multiple processing layers to learn representations of data with multiple levels of abstraction. These methods have dramatically improved the state-of-the-art in speech recognition, visual object recognition, object detection and many other domains such as drug discovery and genomics. Deep learning discovers intricate structure in large data sets by using the backpropagation algorithm to indicate how a machine should change its internal parameters that are used to compute the representation in each layer from the representation in the previous layer. Deep convolutional nets have brought about breakthroughs in processing images, video, speech and audio, whereas recurrent nets have shone light on sequential data such as text and speech. PMID:26017442

  5. Apparent contact angle of an evaporating drop

    NASA Astrophysics Data System (ADS)

    Morris, S. J. S.

    2012-11-01

    In experiments by Poulard et al. (2005), a sessile drop of perfectly wetting liquid evaporates from a non-heated substrate into an under-saturated mixture of vapour with an inert gas; evaporation is limited by vapour diffusion. The system exhibits an apparent contact angle θ that is a flow property. Under certain conditions, the apparent contact line was stationary relative to the substrate; we predict θ for this case. Observed values of θ are small, allowing lubrication analysis of the liquid film. The liquid and vapour flows are coupled through conditions holding at the phase interface; in particular, vapour partial pressure there is related to the local value of liquid pressure through the Kelvin condition. Because the droplet is shallow, the interfacial conditions can be transferred to the solid-liquid interface at y = 0 . We show that the dimensionless partial pressure p (x , y) and the film thickness h (x) are determined by solving ∇2 p = 0 for y > 0 subject to a matching condition at infinity, and the conditions - p = L hxx +h-3 and (h3px) x + 3py = 0 at y = 0 . The parameter L controls the ratio of Laplace to disjoining pressure. We analyse this b.v.p. for the experimentally-relevant case L --> 0 .

  6. Deep Lysimeter

    DOEpatents

    Hubbell, Joel M.; Sisson, James B.

    2004-06-01

    A deep lysimeter including a hollow vessel having a chamber, a fill conduit extending into the chamber through apertures, a semi-permeable member mounted on the vessel and in fluid communication with the fill conduit, and a line connection for retrieving the lysimeter.

  7. Computing the apparent centroid of radar targets

    SciTech Connect

    Lee, C.E.

    1996-12-31

    A high-frequency multibounce radar scattering code was used as a simulation platform for demonstrating an algorithm to compute the ARC of specific radar targets. To illustrate this simulation process, several targets models were used. Simulation results for a sphere model were used to determine the errors of approximation associated with the simulation; verifying the process. The severity of glint induced tracking errors was also illustrated using a model of an F-15 aircraft. It was shown, in a deterministic manner, that the ARC of a target can fall well outside its physical extent. Finally, the apparent radar centroid simulation based on a ray casting procedure is well suited for use on most massively parallel computing platforms and could lead to the development of a near real-time radar tracking simulation for applications such as endgame fuzing, survivability, and vulnerability analyses using specific radar targets and fuze algorithms.

  8. Ambiguity in Tactile Apparent Motion Perception

    PubMed Central

    Liaci, Emanuela; Bach, Michael; Tebartz van Elst, Ludger; Heinrich, Sven P.; Kornmeier, Jürgen

    2016-01-01

    Background In von Schiller’s Stroboscopic Alternative Motion (SAM) stimulus two visually presented diagonal dot pairs, located on the corners of an imaginary rectangle, alternate with each other and induce either horizontal, vertical or, rarely, rotational motion percepts. SAM motion perception can be described by a psychometric function of the dot aspect ratio (“AR”, i.e. the relation between vertical and horizontal dot distances). Further, with equal horizontal and vertical dot distances (AR = 1) perception is biased towards vertical motion. In a series of five experiments, we presented tactile SAM versions and studied the role of AR and of different reference frames for the perception of tactile apparent motion. Methods We presented tactile SAM stimuli and varied the ARs, while participants reported the perceived motion directions. Pairs of vibration stimulators were attached to the participants’ forearms and stimulator distances were varied within and between forearms. We compared straight and rotated forearm conditions with each other in order to disentangle the roles of exogenous and endogenous reference frames. Results Increasing the tactile SAM’s AR biased perception towards vertical motion, but the effect was weak compared to the visual modality. We found no horizontal disambiguation, even for very small tactile ARs. A forearm rotation by 90° kept the vertical bias, even though it was now coupled with small ARs. A 45° rotation condition with crossed forearms, however, evoked a strong horizontal motion bias. Discussion Existing approaches to explain the visual SAM bias fail to explain the current tactile results. Particularly puzzling is the strong horizontal bias in the crossed-forearm conditions. In the case of tactile apparent motion, there seem to be no fixed priority rule for perceptual disambiguation. Rather the weighting of available evidence seems to depend on the degree of stimulus ambiguity, the current situation and on the perceptual

  9. PDGFR signaling blockade in marrow stroma impairs lung cancer bone metastasis.

    PubMed

    Catena, Raúl; Luis-Ravelo, Diego; Antón, Iker; Zandueta, Carolina; Salazar-Colocho, Pablo; Larzábal, Leyre; Calvo, Alfonso; Lecanda, Fernando

    2011-01-01

    Bone microenvironment and cell-cell interactions are crucial for the initiation and development of metastasis. By means of a pharmacologic approach, using the multitargeted tyrosine kinase inhibitor sunitinib, we tested the relevance of the platelet-derived growth factor receptor (PDGFR) axis in the bone marrow (BM) stromal compartment for the initiation and development of lung cancer metastasis to bone. PDGFRβ was found to be the main tyrosine kinase target of sunitinib expressed in BM stromal ST-2 and MC3T3-E1 preosteoblastic cells. In contrast, no expression of sunitinib-targeted receptors was found in A549M1 and low levels in H460M5 lung cancer metastatic cells. Incubation of ST-2 and human BM endothelial cells with sunitinib led to potent cell growth inhibition and induction of apoptosis in a dose-dependent manner. Similarly, sunitinib induced a robust proapoptotic effect in vivo on BM stromal PDGFRβ(+) cells and produced extensive disruption of tissue architecture and vessel leakage in the BM cavity. Pretreatment of ST-2 cells with sunitinib also hindered heterotypic adhesion to lung cancer cell lines. These effects were correlated with changes in cell-cell and cell-matrix molecules in both stromal and tumor cells. Pretreatment of mice with sunitinib before intracardiac inoculation of A549M1 or H460M5 cells caused marked inhibition of tumor cells homing to bone, whereas no effect was found when tumor cells were pretreated before inoculation. Treatment with sunitinib dramatically increased overall survival and prevented tumor colonization but not bone lesions, whereas combination with zoledronic acid resulted in marked reduction of osteolytic lesions and osseous tumor burden. Thus, disruption of the PDGFR axis in the BM stroma alters heterotypic tumor-stromal and tumor-matrix interactions, thereby preventing efficient engagement required for bone homing and osseous colonization. These results support the notion that concomitant targeting of the tumor and

  10. THE TREATMENT-RESISTANT MESENCHYMAL SIGNATURE IN GLIOBLASTOMA DERIVES FROM TUMOR CELLS INDEPENDENT OF STROMA

    PubMed Central

    Sulman, Erik P.; Wang, Qianghu; Ezhilarasan, Ravesanker; Goodman, Lindsey D.; Gumen, Joy; Sun, Peng; Aldape, Ken; Alfred Yung, WK; Heffernan, Timothy; Draetta, Giulio F.; Lang, Frederick F.

    2014-01-01

    identified a total of 5 gene-expression clusters. GSCs in only one of these clusters showed enrichment for a unique TCGA class, mesenchymal. GSCs in other clusters were divided among multiple TCGA classes. CONCLUSIONS: Mesenchymal glioblastomas are derived from mesenchymal GSCs, suggesting that the tumor component is the largest contributor to the aggressive biology of this subtype. GSCs from other tumor subtypes correlate to multiple TCGA classes, suggesting that tumor stroma may contribute to the expression phenotype in those cases. Therapeutics targeting the microenvironment, such as anti-angiogenesis drugs, may have a greater role in non-mesenchymal tumors where the stromal contribution is more prominent. SECONDARY CATEGORY: Neuropathology & Tumor Biomarkers.

  11. Apparent place of Polaris and apparent Sidereal Time at 0 hour UT 1990-1994

    NASA Astrophysics Data System (ADS)

    1990-07-01

    The apparent right ascension and declination of Polaris and the Greenwich Sidereal Time at 0 hour Universal Time for each day is given. Tabulated apparent place coordinates are generated from the Fifth Fundamental Catalogue (FK5). Note that values for 1990 were previously published using the Fourth Fundamental Catalogue (FK4). Although values for apparent right ascension and declination of Polaris and Greenwich Sidereal Time differ between FK4 and FK5, the resulting differences in computed azimuth are small. The publication is prepared for the convenience of the surveyor who observes Polaris for azimuth control to orient a field survey project. The right ascension and declination values can be linearly interpolated directly from the tables using as an argument the decimal part (Universal Time converted to the decimal part of the day) of the Greenwich Civil Day (GCD).

  12. Apparent Attenuation Beneath the United States and its Correlation with Lithospheric Provinces

    NASA Astrophysics Data System (ADS)

    Kowalke, S.; Bezada, M. J.

    2015-12-01

    We map apparent attenuation beneath the continental United States through an analysis of ~16 deep-focus teleseismic events recorded by the USArray Transportable Array. For each event, we stack the best quality recordings to generate a source estimate and then apply an attenuation operator to the source estimate using a range of t* values to fit the record at each station. The regional attenuation pattern is extracted from the ensemble of observations using a regularized inversion scheme. Preliminary results from the analysis of four events show good correlation with tectonic boundaries. The lowest apparent attenuation occurs in the upper Midwest, and corresponds to the Superior Craton; while high apparent attenuation dominates outside the cratonic continent as defined by the Rocky Mountain, Ouachita and Appalachian fronts. Our results indicate that different lithospheric provinces have distinct attenuation signatures that are consistent with expectations.

  13. SPARC-Independent Delivery of Nab-Paclitaxel without Depleting Tumor Stroma in Patient-Derived Pancreatic Cancer Xenografts.

    PubMed

    Kim, Harrison; Samuel, Sharon; Lopez-Casas, Pedro; Grizzle, William; Hidalgo, Manuel; Kovar, Joy; Oelschlager, Denise; Zinn, Kurt; Warram, Jason; Buchsbaum, Donald

    2016-04-01

    The study goal was to examine the relationship between nab-paclitaxel delivery and SPARC (secreted protein acidic and rich in cysteine) expression in pancreatic tumor xenografts and to determine the antistromal effect of nab-paclitaxel, which may affect tumor vascular perfusion. SPARC-positive and -negative mice bearing Panc02 tumor xenografts (n = 5-6/group) were injected with IRDye 800CW (IR800)-labeled nab-paclitaxel. After 24 hours, tumors were collected and stained with DL650-labeled anti-SPARC antibody, and the correlation between nab-paclitaxel and SPARC distributions was examined. Eight groups of mice bearing either Panc039 or Panc198 patient-derived xenografts (PDX; 4 groups/model, 5 animals/group) were untreated (served as control) or treated with gemcitabine (100 mg/kg body weight, i.p., twice per week), nab-paclitaxel (30 mg/kg body weight, i.v., for 5 consecutive days), and these agents in combination, respectively, for 3 weeks, and tumor volume and perfusion changes were assessed using T2-weighted MRI and dynamic contrast-enhanced (DCE) MRI, respectively. All tumors were collected and stained with Masson's Trichrome Stain, followed by a blinded comparative analysis of tumor stroma density. IR800-nab-paclitaxel was mainly distributed in tumor stromal tissue, but nab-paclitaxel and SPARC distributions were minimally correlated in either SPARC-positive or -negative animals. Nab-paclitaxel treatment neither decreased tumor stroma nor increased tumor vascular perfusion in either PDX model when compared with control groups. These data suggest that the specific tumor delivery of nab-paclitaxel is not directly related to SPARC expression, and nab-paclitaxel does not deplete tumor stroma in general. Mol Cancer Ther; 15(4); 680-8. ©2016 AACR. PMID:26832793

  14. Transforming growth factor beta2 inhibits adipocyte differentiation induced by skeletal unloading in rat bone marrow stroma.

    PubMed

    Ahdjoudj, Souhila; Lasmoles, Françoise; Holy, Xavier; Zerath, Erik; Marie, Pierre J

    2002-04-01

    Skeletal unloading induced by hindlimb suspension in rats reduces bone formation and induces osteopenia, but its effect on adipogenesis is unknown. We assessed the effects of unloading and transforming growth factor (TGF) beta2 on bone marrow stromal cell adipocyte differentiation in relation with osteoblast differentiation. Skeletal unloading rapidly (4-7 days) decreased osteoblast transcription factor Runx2, osteocalcin (OC), and type I collagen messenger RNA (mRNA) levels and reduced bone formation in the long bone metaphysis. Conversely, unloading increased expression of the adipocyte transcription factor peroxisome proliferator-activated receptor gamma2 (PPARgamma2) at 4 days and increased expression of the adipocyte differentiation genes lipoprotein lipase (LPL) and aP2 in the bone marrow stroma at 7 days. Consistently, unloading increased the number and volume of adipocytes in the bone marrow stroma. Continuous (0-7 days) and late (4-7 days) treatments with TGF-beta2 corrected the abnormal expression of Cbfa1/Runx2, OC, and type I collagen mRNAs and normalized bone formation in unloaded metaphyseal bone. Moreover, both TGF-beta2 treatments decreased PPARy2 and C/EBPalpha mRNA levels at 4 days and normalized aP2 and LPL expression and adipocyte number and volume at 7 days. These results show that skeletal unloading increases adipocyte differentiation concomitantly with inhibition of osteoblast differentiation. These abnormalities are prevented and reversed by TGF-beta2, suggesting a role for TGF-beta in the control of adipogenic differentiation in the bone marrow stroma. PMID:11918224

  15. Elevated expression of chemokine C-C ligand 2 in stroma is associated with recurrent basal-like breast cancers.

    PubMed

    Yao, Min; Yu, Elaine; Staggs, Vincent; Fan, Fang; Cheng, Nikki

    2016-08-01

    Despite advances in treatment, up to 30% of breast cancer patients experience disease recurrence accompanied by more aggressive disease and poorer prognosis. Treatment of breast cancer is complicated by the presence of multiple breast cancer subtypes, including: luminal, Her2 overexpressing, and aggressive basal-like breast cancers. Identifying new biomarkers specific to breast cancer subtypes could enhance the prediction of patient prognosis and contribute to improved treatment strategies. The microenvironment influences breast cancer progression through expression of growth factors, angiogenic factors and other soluble proteins. In particular, chemokine C-C ligand 2 (CCL2) regulates macrophage recruitment to primary tumors and signals to cancer cells to promote breast tumor progression. Here we employed a software-based approach to evaluate the prognostic significance of CCL2 protein expression in breast cancer subtypes in relation to its expression in the epithelium or stroma or in relation to fibroblast-specific protein 1 (Fsp1), a mesenchymal marker. Immunohistochemistry analysis of tissue microarrays revealed that CCL2 significantly correlated with Fsp1 expression in the stroma and tumor epithelium of invasive ductal carcinoma. In the overall cohort of invasive ductal carcinomas (n=427), CCL2 and Fsp1 expression in whole tissues, stroma and epithelium were inversely associated with cancer stage and tumor size. When factoring in molecular subtype, stromal CCL2 was observed to be most highly expressed in basal-like breast cancers. By Cox regression modeling, stromal CCL2, but not epithelial CCL2, expression was significantly associated with decreased recurrence-free survival. Furthermore, stromal CCL2 (HR=7.51 P=0.007) was associated with a greater hazard than cancer stage (HR=2.45, P=0.048) in multivariate analysis. These studies indicate that stromal CCL2 is associated with decreased recurrence-free survival in patients with basal-like breast cancer, with

  16. Stromal progesterone receptors mediate induction of Indian Hedgehog (IHH) in uterine epithelium and its downstream targets in uterine stroma.

    PubMed

    Simon, Liz; Spiewak, Kerry A; Ekman, Gail C; Kim, Jaeyeon; Lydon, John P; Bagchi, Milan K; Bagchi, Indrani C; DeMayo, Francesco J; Cooke, Paul S

    2009-08-01

    Uterine receptivity to embryo implantation depends on appropriate progesterone (P4) and estrogen stimulation. P4 rapidly stimulates production of the morphogen Indian hedgehog (IHH) in murine uterine epithelium as well as downstream molecules in the hedgehog pathway such as Patched homolog 1 (PTCH1) and nuclear receptor subfamily 2, group F, member 2 (NR2F2) in uterine stroma. Studies using IHH-null mice indicate that IHH is obligatory for the normal P4 response in the uterus. To determine whether IHH induction in uterine epithelium is mediated through P4 receptor (PR) in epithelium (E) and/or stroma (S), we produced tissue recombinants using uteri from neonatal PR knockout (ko) mice and wild-type (wt) mice containing PR in S and/or E or lacking PR altogether using a tissue recombinant methodology and assessed their response to P4. In tissue recombinants containing wt-S (wt-S + wt-E and wt-S + ko-E), P4 induced Ihh mRNA expression at 6 h that was 6-fold greater than in oil-treated controls (P < 0.05; n = 6) in both types of tissue recombinants despite the absence of epithelial PR in wt-S + ko-E grafts. Conversely, Ihh mRNA expression was unaffected by P4 in ko-S + ko-E and ko-S + wt-E grafts despite epithelial PR expression in the latter. Nr2f2 and Ptch1 mRNA expression was similar in that it was stimulated by P4 only in recombinants containing stromal PR. These results indicate that stromal PR is both necessary and sufficient for P4 stimulation of epithelial IHH as well as downstream events such as PTCH1 and NR2F2 increases in stroma. PMID:19372202

  17. Biochemical characterization of nuclear receptors for vitamin D{sub 3} and glucocorticoids in prostate stroma cell microenvironment

    SciTech Connect

    Hidalgo, Alejandro A.; Montecinos, Viviana P.; Paredes, Roberto; Godoy, Alejandro S.; McNerney, Eileen M.; Tovar, Heribelt; Pantoja, Diego; Johnson, Candace; Trump, Donald; Onate, Sergio A.

    2011-08-19

    Highlights: {yields} Fibroblasts from benign and carcinoma-associated stroma were biochemically characterized for VDR and GR function as transcription factors in prostate stroma cell microenvironment. {yields} Decreased SRC-1/CBP coactivators recruitment to VDR and GR may result in hormone resistance to 1,25D{sub 3} in stromal cell microenvironment prostate cancer. {yields} 1a,25-Dyhidroxyvitamin D{sub 3} (1,25D{sub 3}) and glucocorticoids, either alone or in combination, may not be an alternative for 'some' advanced prostate cancers that fails androgen therapies. -- Abstract: The disruption of stromal cell signals in prostate tissue microenvironment influences the development of prostate cancer to androgen independence. 1{alpha},25-Dihydroxyvitamin D{sub 3} (1,25D{sub 3}) and glucocorticoids, either alone or in combination, have been investigated as alternatives for the treatment of advanced prostate cancers that fails androgen therapies. The effects of glucocorticoids are mediated by the intracellular glucocorticoid receptor (GR). Similarly, the effect of 1,25D{sub 3} is mediated by the 1,25D{sub 3} nuclear receptor (VDR). In this study, fibroblasts from benign- (BAS) and carcinoma-associated stroma (CAS) were isolated from human prostates to characterize VDR and GR function as transcription factors in prostate stroma. The VDR-mediated transcriptional activity assessed using the CYP24-luciferase reporter was limited to 3-fold induction by 1,25D{sub 3} in 9 out of 13 CAS (70%), as compared to >10-fold induction in the BAS clinical sample pair. Expression of His-tagged VDR (Ad-his-VDR) failed to recover the low transcriptional activity of the luciferase reporter in 7 out of 9 CAS. Interestingly, expression of Ad-his-VDR successfully recovered receptor-mediated induction in 2 out of the 9 CAS analyzed, suggesting that changes in the receptor protein itself was responsible for decreased response and resistance to 1,25D{sub 3} action. Conversely, VDR

  18. Renal cell carcinoma with angioleiomyoma-like stroma: clinicopathological, immunohistochemical, and molecular features supporting classification as a distinct entity.

    PubMed

    Williamson, Sean R; Cheng, Liang; Eble, John N; True, Lawrence D; Gupta, Nilesh S; Wang, Mingsheng; Zhang, Shaobo; Grignon, David J

    2015-02-01

    Rare renal epithelial neoplasms have been recognized to have an angioleiomyoma or leiomyoma-like proliferation of stromal smooth muscle; however, the nature of these tumors and their relationships to other renal cell carcinomas are poorly understood. We analyzed 23 such tumors for their clinicopathological, immunohistochemical, and cytogenetic features using fluorescence in situ hybridization. Twelve showed a homogeneous combination of features and were reclassified as renal cell carcinoma with angioleiomyoma-like stroma. These were composed of neoplastic glandular structures lined by cells with mixed clear, pale, and eosinophilic cytoplasm forming occasional papillary tufts. The stroma resembled smooth muscle and often extended away from the epithelial component, entrapping perinephric fat or non-neoplastic renal elements. Immunohistochemistry showed the epithelium to have reactivity for: carbonic anhydrase IX, CD10, vimentin, cytokeratin 7, cytokeratin 34βE12, and PAX8 but not α-methylacyl-coA-racemase. The stroma labeled for smooth muscle (smooth muscle actin 3+, desmin 1+, caldesmon 3+) but not epithelial antigens. Neither component showed substantial reactivity for HMB45, melan-A, cathepsin K, or TFE3 protein. An interrupted, conspicuous layer of CD34-positive endothelial cells rimmed the epithelium, imparting a two-cell layer pattern resembling myoepithelial or basal cells. Chromosome 3p deletion and trisomy 7 and 17 were uniformly absent. Follow-up was available for three patients, none of whom experienced malignant behavior. Eleven tumors were excluded from this category and considered to be clear cell renal cell carcinoma with a reactive proliferation of smooth muscle (n=4) or tangential sectioning of the pseudocapsule (n=2), renal cell carcinoma unclassified (n=4), or clear cell papillary renal cell carcinoma (n=1). In summary, renal cell carcinoma with angioleiomyoma-like stroma is a distinct neoplasm with characteristic morphological

  19. Finding apparent horizons in numerical relativity

    NASA Astrophysics Data System (ADS)

    Thornburg, Jonathan

    1996-10-01

    We review various algorithms for finding apparent horizons in 3+1 numerical relativity. We then focus on one particular algorithm, in which we pose the apparent horizon equation H≡∇ini+Kijninj-K=0 as a nonlinear elliptic (boundary-value) PDE on angular-coordinate space for the horizon shape function r=h(θ,φ), finite difference this PDE, and use Newton's method or a variant to solve the finite difference equations. We describe a method for computing the Jacobian matrix of the finite differenced H(h) sH (sh) function by symbolically differentiating the finite difference equations, giving the Jacobian elements directly in terms of the finite difference molecule coefficients used in computing sH (sh). Assuming the finite differencing scheme commutes with linearization, we show how the Jacobian elements may be computed by first linearizing the continuum H(h) equations, then finite differencing the linearized continuum equations. (This is essentially just the ``Jacobian part'' of the Newton-Kantorovich method for solving nonlinear PDEs.) We tabulate the resulting Jacobian coefficients for a number of different sH (sh) and Jacobian computation schemes. We find this symbolic differentiation method of computing the Jacobian to be much more efficient than the usual numerical-perturbation method, and also much easier to implement than is commonly thought. When solving the discrete sH (sh)=0 equations, we find that Newton's method generally shows robust convergence. However, we find that it has a small (poor) radius of convergence if the initial guess for the horizon position contains significant high-spatial-frequency error components, i.e., angular Fourier components varying as (say) cosmθ with m>~8. (Such components occur naturally if spacetime contains significant amounts of high-frequency gravitational radiation.) We show that this poor convergence behavior is not an artifact of insufficient resolution in the finite difference grid; rather, it appears to be caused

  20. The absence of aldehyde dehydrogenase 1 A1-positive cells in benign mammary stroma is associated with risk factors for breast cancer

    PubMed Central

    Isfoss, Björn Logi; Holmqvist, Bo; Jernström, Helena; Alm, Per; Olsson, Håkan

    2016-01-01

    In this study, aldehyde dehydrogenase 1 (ALDH1)-expressing cells in stroma of histologically normal breast tissue from premenopausal women were investigated in situ regarding cellular morphology, cell distribution, and relation to the additional stem cell markers, CD44 (+) and CD24 (−). These results were correlated with hormonal and genetic risk factors for breast cancer. Triple immunofluorescence labeling was performed on tissues from premenopausal women with a family history of breast cancer, and breast reduction specimens from premenopausal women with no family history of breast cancer were used as a control group. The majority of ALDH1-immunoreactive cells in stroma were spindle-shaped or polygonal, and such cells that were CD44− and CD24− were absent in the breast stroma of a significantly larger number of nulliparous than parous women. A less common morphological type of ALDH1-positive cells in stroma was round or oval in shape, and such cells that were CD44+ and CD24− were absent in a significant number of women with a family history of breast cancer. The CD44+/CD24− immunophenotype is consistent with stem cells, and the round/oval morphology suggests mesenchymal cells. This study demonstrates that there are two morphologically distinct types of ALDH1-positive cells in histologically benign mammary stroma, and the absence of these cells is correlated with clinical risk factors for breast cancer in premenopausal women. PMID:27313475

  1. The absence of aldehyde dehydrogenase 1 A1-positive cells in benign mammary stroma is associated with risk factors for breast cancer.

    PubMed

    Isfoss, Björn Logi; Holmqvist, Bo; Jernström, Helena; Alm, Per; Olsson, Håkan

    2016-01-01

    In this study, aldehyde dehydrogenase 1 (ALDH1)-expressing cells in stroma of histologically normal breast tissue from premenopausal women were investigated in situ regarding cellular morphology, cell distribution, and relation to the additional stem cell markers, CD44 (+) and CD24 (-). These results were correlated with hormonal and genetic risk factors for breast cancer. Triple immunofluorescence labeling was performed on tissues from premenopausal women with a family history of breast cancer, and breast reduction specimens from premenopausal women with no family history of breast cancer were used as a control group. The majority of ALDH1-immunoreactive cells in stroma were spindle-shaped or polygonal, and such cells that were CD44(-) and CD24(-) were absent in the breast stroma of a significantly larger number of nulliparous than parous women. A less common morphological type of ALDH1-positive cells in stroma was round or oval in shape, and such cells that were CD44(+) and CD24(-) were absent in a significant number of women with a family history of breast cancer. The CD44(+)/CD24(-) immunophenotype is consistent with stem cells, and the round/oval morphology suggests mesenchymal cells. This study demonstrates that there are two morphologically distinct types of ALDH1-positive cells in histologically benign mammary stroma, and the absence of these cells is correlated with clinical risk factors for breast cancer in premenopausal women. PMID:27313475

  2. Apparent diamagnetic response of an inhomogeneous ferromagnet

    SciTech Connect

    Claus, H.; Veal, B.W.

    1997-07-01

    We present magnetization measurements on a weakly ferromagnetic Pd 0.5 at.{percent} Fe alloy (T{sub c}=15 K). Due to the preparation technique for the sample, it has a thin surface layer with slightly enhanced T{sub c}. In fields above 200 mG, the magnetization is typical of a ferromagnet. However, when cooling in very small fields ({ital H}{lt}25 mG), the magnetization reverses its direction at low temperatures, apparently becoming diamagnetic. The effect is very similar, but of opposite sign, to that observed in some high-T{sub c} superconducting samples where the magnetization becomes paramagnetic on field cooling (paramagnetic Meissner effect, PME). Whereas the origin of the PME in superconductors is controversial, the effect in our ferromagnetic sample is explained in terms of dipolar polarization of the interior of the sample by the surface layer with enhanced T{sub c}. Removing the surface layer eliminates this anomalous effect and the sample behaves like an ordinary ferromagnet, down to the lowest fields. {copyright} {ital 1997} {ital The American Physical Society}

  3. Apparent speed increases at low luminance

    PubMed Central

    Vaziri-Pashkam, Maryam; Cavanagh, Patrick

    2009-01-01

    To investigate the effect of luminance on apparent speed, subjects adjusted the speed of a low-luminance rotating grating (0.31 cd/m2) to match that of a high-luminance one (1260 cd/m2). Above 4 Hz, subjects overestimated the speed of the low-luminance grating. This overestimation increased as a function of temporal rate and reached 30% around 10 Hz temporal rates. The speed overestimation became significant once the lower luminance was 2.4 log units lower than the high luminance comparison. Next the role of motion smear in speed overestimation was examined. First it was shown that the length of the perceived motion smear increased at low luminances. Second, the length of the visible smear was manipulated by changing the presentation time of the stimuli. Speed overestimation was reduced at shorter presentation times. Third the speed of a blurred stimulus was compared to a stimulus with sharp edges and the blurred stimulus was judged to move faster. These results indicate that the length of motion smear following a target contributes to its perceived speed and that this leads to speed overestimation at low luminance where motion traces lengthen because of increased persistence. PMID:19146275

  4. Observations that Constrain the Scaling of Apparent Stress

    NASA Astrophysics Data System (ADS)

    McGarr, A.; Fletcher, J. B.

    2002-12-01

    Slip models developed for major earthquakes are composed of distributions of fault slip, rupture time, and slip velocity time function over the rupture surface, as divided into many smaller subfaults. Using a recently-developed technique, the seismic energy radiated from each subfault can be estimated from the time history of slip there and the average rupture velocity. Total seismic energies, calculated by summing contributions from all of the subfaults, agree reasonably well with independent estimates based on seismic energy flux in the far-field at regional or teleseismic distances. Two recent examples are the 1999 Izmit, Turkey and the 1999 Hector Mine, California earthquakes for which the NEIS teleseismic measurements of radiated energy agree fairly closely with seismic energy estimates from several different slip models, developed by others, for each of these events. Similar remarks apply to the 1989 Loma Prieta, 1992 Landers, and 1995 Kobe earthquakes. Apparent stresses calculated from these energy and moment results do not indicate any moment or magnitude dependence. The distributions of both fault slip and seismic energy radiation over the rupture surfaces of earthquakes are highly inhomogeneous. These results from slip models, combined with underground and seismic observations of slip for much smaller mining-induced earthquakes, can provide stronger constraint on the possible scaling of apparent stress with moment magnitude M or seismic moment. Slip models for major earthquakes in the range M6.2 to M7.4 show maximum slips ranging from 1.6 to 8 m. Mining-induced earthquakes at depths near 2000 m in South Africa are associated with peak slips of 0.2 to 0.37 m for events of M4.4 to M4.6. These maximum slips, whether derived from a slip model or directly observed underground in a deep gold mine, scale quite definitively as the cube root of the seismic moment. In contrast, peak slip rates (maximum subfault slip/rise time) appear to be scale invariant. A 1.25 m

  5. c-Met identifies a population of matrix metalloproteinase 9-producing monocytes in peritumoural stroma of hepatocellular carcinoma.

    PubMed

    Zhao, Lan; Wu, Yan; Xie, Xu-Dong; Chu, Yi-Fan; Li, Jin-Qing; Zheng, Limin

    2015-11-01

    Macrophages (Mϕ) are prominent components of solid tumours and exhibit distinct phenotypes in different microenvironments. Previously, we found that tumours could alter the normal developmental process of Mϕ to trigger transient activation of monocytes in the peritumoural stroma of human hepatocellular carcinoma (HCC). In the present study, we showed that a fraction of monocytes in the peritumoural stroma, but not in HCC cancer nests, expressed surface c-Met molecules. Monocytes exposed to tumours strongly expressed c-Met proteins with kinetics similar to their activation status, and significant correlations were found between c-Met levels and HLA-DR expression on tumour-infiltrating monocytes. NF-κB-mediated autocrine TNF-α stimulated the expression of c-Met on activated monocytes, and by interacting with its ligand hepatocyte growth factor (HGF), c-Met increased the motility and matrix metalloproteinase (MMP) 9-producing capacity of tumour-associated monocytes. The intensity of c-Met expression on tumour-infiltrating monocytes was associated with high mortality and reduced survival of patients with HCC. Therefore, the expression of c-Met on activated monocytes/Mϕ may represent a novel mechanism by which a tumour actively and precisely regulates the distribution and functions of these cells to facilitate disease progression. PMID:26108200

  6. Modulation of Smad signaling by non-TGFβ components in myofibroblast generation during wound healing in corneal stroma.

    PubMed

    Saika, Shizuya; Yamanaka, Osamu; Okada, Yuka; Sumioka, Takayoshi

    2016-01-01

    Corneal scarring/fibrosis disturbs normal transparency and curvature of the tissue and thus impairs vision. The lesion is characterized by appearance of myofibroblasts, the key player of the fibrogenic reaction, and excess accumulation of extracellular matrix. Inflammatory/fibrogenic growth factors or cytokines expressed in inflammatory cells that infiltrate into injured tissues play a pivotal role in fibrotic tissue formation. In this article the pathogenesis of fibrosis/scarring in the corneal stroma is reviewed focusing on the roles of myofibroblast, the key player in corneal stromal wound healing and fibrosis, and cytoplasmic signals activated by the fibrogenic cytokine, transforming growth factor β (TGFβ). Although it is established that TGFβ/Smad signal is essential to the process of keratocyte-myofibroblast transformation in a healing corneal stroma post-injury. This article emphasizes the involvement of non-TGFβ molecular mechanisms in modulating Smad signal. We focus on the roles of matricellular proteins, i.e., osteopontin and tenascin C, and as cellular components, the roles of transient receptor potential (TRP) cation channel receptors are discussed. Our intent is to draw attention to the possibility of signal transduction cascade modulation (e.g., Smad signal and mitogen-activated protein kinases, by gene transfer and other related technology) as being beneficial in a clinical setting to reduce or even prevent corneal stromal tissue fibrosis/scarring and inflammation. PMID:26675402

  7. Thyroid hormones and tetrac: new regulators of tumour stroma formation via integrin αvβ3.

    PubMed

    Schmohl, Kathrin A; Müller, Andrea M; Wechselberger, Alexandra; Rühland, Svenja; Salb, Nicole; Schwenk, Nathalie; Heuer, Heike; Carlsen, Janette; Göke, Burkhard; Nelson, Peter J; Spitzweg, Christine

    2015-12-01

    To improve our understanding of non-genomic, integrin αvβ3-mediated thyroid hormone action in tumour stroma formation, we examined the effects of triiodo-l-thyronine (T3), l-thyroxine (T4) and integrin-specific inhibitor tetrac on differentiation, migration and invasion of mesenchymal stem cells (MSCs) that are an integral part of the tumour's fibrovascular network. Primary human bone marrow-derived MSCs were treated with T3 or T4 in the presence of hepatocellular carcinoma (HCC) cell-conditioned medium (CM), which resulted in stimulation of the expression of genes associated with cancer-associated fibroblast-like differentiation as determined by qPCR and ELISA. In addition, T3 and T4 increased migration of MSCs towards HCC cell-CM and invasion into the centre of three-dimensional HCC cell spheroids. All these effects were tetrac-dependent and therefore integrin αvβ3-mediated. In a subcutaneous HCC xenograft model, MSCs showed significantly increased recruitment and invasion into tumours of hyperthyroid mice compared to euthyroid and, in particular, hypothyroid mice, while treatment with tetrac almost completely eliminated MSC recruitment. These studies significantly improve our understanding of the anti-tumour activity of tetrac, as well as the mechanisms that regulate MSC differentiation and recruitment in the context of tumour stroma formation, as an important prerequisite for the utilisation of MSCs as gene delivery vehicles. PMID:26307023

  8. Identification of multipotent mesenchymal stromal cells in the reactive stroma of a prostate cancer xenograft by side population analysis

    SciTech Connect

    Santamaria-Martinez, Albert; Barquinero, Jordi; Barbosa-Desongles, Anna; Hurtado, Antoni; Pinos, Tomas; Seoane, Joan; Poupon, Marie-France; Morote, Joan; Reventos, Jaume; Munell, Francina

    2009-10-15

    Cancer stem cells are a distinct cellular population that is believed to be responsible for tumor initiation and maintenance. Recent data suggest that solid tumors also contain another type of stem cells, the mesenchymal stem cells or multipotent mesenchymal stromal cells (MSCs), which contribute to the formation of tumor-associated stroma. The Hoechst 33342 efflux assay has proved useful to identify a rare cellular fraction, named Side Population (SP), enriched in cells with stem-like properties. Using this assay, we identified SP cells in a prostate cancer xenograft containing human prostate cancer cells and mouse stromal cells. The SP isolation, subculture and sequential sorting allowed the generation of single-cell-derived clones of murine origin that were recognized as MSC by their morphology, plastic adherence, proliferative potential, adipogenic and osteogenic differentiation ability and immunophenotype (CD45{sup -}, CD81{sup +} and Sca-1{sup +}). We also demonstrated that SP clonal cells secrete transforming growth factor {beta}1 (TGF-{beta}1) and that their inhibition reduces proliferation and accelerates differentiation. These results reveal the existence of SP cells in the stroma of a cancer xenograft, and provide evidence supporting their MSC nature and the role of TGF-{beta}1 in maintaining their proliferation and undifferentiated status. Our data also reveal the usefulness of the SP assay to identify and isolate MSC cells from carcinomas.

  9. Targeted Disruption of Orchestration between Stroma and Tumor Cells in Pancreatic Cancer: Molecular Basis and Therapeutic Implications

    PubMed Central

    Kong, Xiangyu; Li, Lei; Li, Zhaoshen; Xie, Keping

    2012-01-01

    Pancreatic cancer is one of the most lethal malignancies, with a prominent desmoplastic reaction as the defining hallmark of the disease. The past several decades have seen dramatic progress in understanding of pancreatic cancer pathogenesis, including the identification of precursor lesions, sequential transformation from normal pancreas to invasive pancreatic cancer and corresponding signature genetic events, and the biological impact of those alterations on malignant behaviors. However, the current therapeutic strategies for epithelial tumor cells, which have exhibited potent antitumor activity in cell culture and animal models, have failed to have significant effects in the clinic. The desmoplastic stroma surrounding pancreatic cancer cells, which accounts for about 90% of a tumor’s mass, clearly is not a passive scaffold for cancer cells but an active contributor to carcinogenesis. Improved understanding of the dynamic interaction between cancer cells and their stroma will be important to designing new, effective therapeutic strategies for pancreatic cancer. This review focuses on the origination of stromal molecular and cellular components in pancreatic tumors, their biological effects on pancreatic cancer cells, and the orchestration between these two components. PMID:22749856

  10. Automatic Tumor-Stroma Separation in Fluorescence TMAs Enables the Quantitative High-Throughput Analysis of Multiple Cancer Biomarkers

    PubMed Central

    Lahrmann, Bernd; Halama, Niels; Sinn, Hans-Peter; Schirmacher, Peter; Jaeger, Dirk; Grabe, Niels

    2011-01-01

    The upcoming quantification and automation in biomarker based histological tumor evaluation will require computational methods capable of automatically identifying tumor areas and differentiating them from the stroma. As no single generally applicable tumor biomarker is available, pathology routinely uses morphological criteria as a spatial reference system. We here present and evaluate a method capable of performing the classification in immunofluorescence histological slides solely using a DAPI background stain. Due to the restriction to a single color channel this is inherently challenging. We formed cell graphs based on the topological distribution of the tissue cell nuclei and extracted the corresponding graph features. By using topological, morphological and intensity based features we could systematically quantify and compare the discrimination capability individual features contribute to the overall algorithm. We here show that when classifying fluorescence tissue slides in the DAPI channel, morphological and intensity based features clearly outpace topological ones which have been used exclusively in related previous approaches. We assembled the 15 best features to train a support vector machine based on Keratin stained tumor areas. On a test set of TMAs with 210 cores of triple negative breast cancers our classifier was able to distinguish between tumor and stroma tissue with a total overall accuracy of 88%. Our method yields first results on the discrimination capability of features groups which is essential for an automated tumor diagnostics. Also, it provides an objective spatial reference system for the multiplex analysis of biomarkers in fluorescence immunohistochemistry. PMID:22164226

  11. Overexpression of FGF9 in prostate epithelial cells augments reactive stroma formation and promotes prostate cancer progression.

    PubMed

    Huang, Yanqing; Jin, Chengliu; Hamana, Tomoaki; Liu, Junchen; Wang, Cong; An, Lei; McKeehan, Wallace L; Wang, Fen

    2015-01-01

    Bone metastasis is the major cause of morbidity and mortality of prostate cancer (PCa). Fibroblast growth factor 9 (FGF9) has been reported to promote PCa bone metastasis. However, the mechanism by which overexpression of FGF9 promotes PCa progression and metastasis is still unknown. Herein, we report that transgenic mice forced to express FGF9 in prostate epithelial cells (F9TG) developed high grade prostatic intraepithelial neoplasia (PIN) in an expression level- and time-dependent manner. Moreover, FGF9/TRAMP bigenic mice (F9TRAMP) grew advanced PCa earlier and had higher frequencies of metastasis than TRAMP littermates. We observed tumor microenvironmental changes including hypercellularity and hyperproliferation in the stromal compartment of F9TG and F9TRAMP mice. Expression of TGFβ1, a key signaling molecule overexpressed in reactive stroma, was increased in F9TG and F9TRAMP prostates. Both in vivo and in vitro data indicated that FGF9 promoted TGFβ1 expression via increasing cJun-mediated signaling. Moreover, in silico analyses showed that the expression level of FGF9 was positively associated with expression of TGFβ1 and its downstream signaling molecules in human prostate cancers. Collectively, our data demonstrated that overexpressing FGF9 in PCa cells augmented the formation of reactive stroma and promoted PCa initiation and progression. PMID:26157349

  12. Pyruvate Dehydrogenase and Pyruvate Dehydrogenase Kinase Expression in Non Small Cell Lung Cancer and Tumor-Associated Stroma1

    PubMed Central

    Koukourakis, Michael I; Giatromanolaki, Alexandra; Sivridis, Efthimios; Gatter, Kevin C; Harris, Adrian L; “Tumor and Angiogenesis Research Group”

    2005-01-01

    Abstract Pyruvate dehydrogenase (PDH) catalyzes the conversion of pyruvate to acetyl-coenzyme A, which enters into the Krebs cycle, providing adenosine triphosphate (ATP) to the cell. PDH activity is under the control of pyruvate dehydrogenase kinases (PDKs). Under hypoxic conditions, conversion of pyruvate to lactate occurs, a reaction catalyzed by lactate dehydrogenase 5 (LDH5). In cancer cells, however, pyruvate is transformed to lactate occurs, regardless of the presence of oxygen (aerobic glycolysis/Warburg effect). Although hypoxic intratumoral conditions account for HIF1α stabilization and induction of anaerobic metabolism, recent data suggest that high pyruvate concentrations also result in HIF1α stabilization independently of hypoxia. In the present immunohistochemical study, we provide evidence that the PDH/PDK pathway is repressed in 73% of non small cell lung carcinomas, which may be a key reason for HIF1α stabilization and “aerobic glycolysis.” However, about half of PDH-deficient carcinomas are not able to switch on the HIF pathway, and patients harboring these tumors have an excellent postoperative outcome. A small subgroup of clinically aggressive tumors maintains a coherent PDH and HIF/LDH5 expression. In contrast to cancer cells, fibroblasts in the tumor-supporting stroma exhibit an intense PDH but reduced PDK1 expression favoring maximum PDH activity. This means that stroma may use lactic acid produced by tumor cells, preventing the creation of an intolerable intratumoral acidic environment at the same time. PMID:15736311

  13. Expression of Autoactivated Stromelysin-1 in Mammary Glands of Transgenic Mice Leads to a Reactive Stroma During Early Development

    SciTech Connect

    Thomasset, N.; Lochter, A.; Sympson, C.J.; Lund, L.R.; Williams, D.R.; Behrendtsen, O.; Werb, Z.; Bissell, M.J.

    1998-04-24

    Extracellular matrix and extracellular matrix-degrading matrix metalloproteinases play a key role in interactions between the epithelium and the mesenchyme during mammary gland development and disease. In patients with breast cancer, the mammary mesenchyme undergoes a stromal reaction, the etiology of which is unknown. We previously showed that targeting of an autoactivating mutant of the matrix metalloproteinase stromelysin-1 to mammary epithelia of transgenic mice resulted in reduced mammary function during pregnancy and development of preneoplastic and neoplastic lesions. Here we examine the cascade of alterations before breast tumor formation in the mammary gland stroma once the expression of the stromelysin-1 transgene commences. Beginning in postpubertal virgin animals, low levels of transgene expression in mammary epithelia led to increased expression of endogenous stromelysin-1 in stromal fibroblasts and up-regulation of other matrix metalloproteinases, without basement membrane disruption. These changes were accompanied by the progressive development of a compensatory reactive stroma, characterized by increased collagen content and vascularization in glands from virgin mice. This remodeling of the gland affected epithelial-mesenchymal communication as indicated by inappropriate expression of tenascin-C starting by day 6 of pregnancy. This, together with increased transgene expression, led to basement membrane disruption starting by day 15 of pregnancy. We propose that the highly reactive stroma provides a prelude to breast epithelial tumors observed in these animals. Epithelial development depends on an exquisite series of inductive and instructive interactions between the differentiating epithelium and the mesenchymal (stromal) compartment. The epithelium, which consists of luminal and myoepithelial cells, is separated from the stroma by a basement membrane (BM), which plays a central role in mammary gland homeostasis and gene expression. In vivo, stromal

  14. Deep smarts.

    PubMed

    Leonard, Dorothy; Swap, Walter

    2004-09-01

    When a person sizes up a complex situation and rapidly comes to a decision that proves to be not just good but brilliant, you think, "That was smart." After you watch him do this a few times, you realize you're in the presence of something special. It's not raw brainpower, though that helps. It's not emotional intelligence, either, though that, too, is often involved. It's deep smarts. Deep smarts are not philosophical--they're not"wisdom" in that sense, but they're as close to wisdom as business gets. You see them in the manager who understands when and how to move into a new international market, in the executive who knows just what kind of talk to give when her organization is in crisis, in the technician who can track a product failure back to an interaction between independently produced elements. These are people whose knowledge would be hard to purchase on the open market. Their insight is based on know-how more than on know-what; it comprises a system view as well as expertise in individual areas. Because deep smarts are experienced based and often context specific, they can't be produced overnight or readily imported into an organization. It takes years for an individual to develop them--and no time at all for an organization to lose them when a valued veteran walks out the door. They can be taught, however, with the right techniques. Drawing on their forthcoming book Deep Smarts, Dorothy Leonard and Walter Swap say the best way to transfer such expertise to novices--and, on a larger scale, to make individual knowledge institutional--isn't through PowerPoint slides, a Web site of best practices, online training, project reports, or lectures. Rather, the sage needs to teach the neophyte individually how to draw wisdom from experience. Companies have to be willing to dedicate time and effort to such extensive training, but the investment more than pays for itself. PMID:15449858

  15. Cold acclimation of Arabidopsis thaliana results in incomplete recovery of photosynthetic capacity, associated with an increased reduction of the chloroplast stroma.

    PubMed

    Savitch, L V; Barker-Astrom, J; Ivanov, A G; Hurry, V; Oquist, G; Huner, N P; Gardeström, P

    2001-12-01

    The effects of short-term cold stress and long-term cold acclimation on the light reactions of photosynthesis were examined in vivo to assess their contributions to photosynthetic acclimation to low temperature in Arabidopsis thaliana (L.) Heynh.. All photosynthetic measurements were made at the temperature of exposure: 23 degrees C for non-acclimated plants and 5 degrees C for cold-stressed and cold-acclimated plants. Three-day cold-stress treatments at 5 degrees C inhibited light-saturated rates of CO2 assimilation and O2 evolution by approximately 75%. The 3-day exposure to 5 degrees C also increased the proportion of reduced QA by 50%, decreased the yield of PSII electron transport by 65% and decreased PSI activity by 31%. In contrast, long-term cold acclimation resulted in a strong but incomplete recovery of light-saturated photosynthesis at 5 degrees C. The rates of light-saturated CO2 and O2 gas exchange and the in vivo yield of PSII activity under light-saturating conditions were only 35-40% lower, and the relative redox state of QA only 20% lower, at 5 degrees C after cold acclimation than in controls at 23 degrees C. PSI activity showed full recovery during long-term cold acclimation. Neither short-term cold stress nor long-term cold acclimation of Arabidopsis was associated with a limitation in ATP, and both treatments resulted in an increase in the ATP/NADPH ratio. This increase in ATP/NADPH was associated with an inhibition of PSI cyclic electron transport but there was no apparent change in the Mehler reaction activity in either cold-stressed or cold-acclimated leaves. Cold acclimation also resulted in an increase in the reduction state of the stroma, as indicated by an increased total activity and activation state of NADP-dependent malate dehydrogenase, and increased light-dependent activities of the major regulatory enzymes of the oxidative pentose-phosphate pathway. We suggest that the photosynthetic capacity during cold stress as well as cold

  16. A New Apparent Polar Wander Path for Antarctica

    NASA Astrophysics Data System (ADS)

    Jovane, L.; Acton, G.; Verosub, K. L.; Florindo, F.; Sagnotti, L.; Wilson, G.

    2006-12-01

    The apparent polar wander path (APWP) for Antarctica contains very few paleomagnetic observations and is probably the most poorly constrained APWP for any of the major lithospheric plates. The poor coverage and temporal distribution of paleomagnetic studies can be attributed to the sparse occurrence of outcrops and to the small number of deep drill cores that have been collected on the continent and surrounding oceans, in part because of high costs and logistical difficulties. In addition, although studies of the Antarctic APWP have not received much attention, global plate reconstructions that link Pacific basin plates to the plates in the Indian and Atlantic Oceans must pass through Antarctica. Understanding the past position and motion of the Antarctic plate is therefore important for plate reconstructions and has implications for geodynamic, geomagnetic, and paleoclimatic studies. We are attempting to refine the Antarctic APWP along Cenozoic by using inclination data from DSDP Sites 270 and 274, ODP Sites 689, 690, 738, 744, 748, 1095, 1096, 1101, 1165, 1166, 1167, and the CIROS-1 and CRP-1, 2 and 3 drill cores. Several of these sites have high sedimentation rates and detailed magnetostratigraphy, which provide high-resolution observation and well- constrained ages. We first divided each of these datasets into several time subunits based on sedimentation rate, data availability and lithological discontinuities and have then combined coeval subunits from different cores. This procedure allows us to estimate paleocolatitudes and "relative" virtual geomagnetic poles (VGPs) along with their confidence limits. The paleocolatitudes from all cores of a given age or time period define multiple small circles of possible paleomagnetic pole positions, and their intersection defines the most probable position of the pole. Angular dispersion of the inclination averages has also been calculated in order to test for secular variation and the goodness of the sampling.

  17. Origin of the impedance cardiogram investigated in the dog by exchange transfusion with a stroma-free haemoglobin solution.

    PubMed

    Visser, K R; Lamberts, R; Poelmann, A M; Zijlstra, W G

    1977-03-11

    In an anaesthetized dog an exchange transfusion was carried out with stroma-free haemoglobin solution. The total circulating blood volume was kept constant. The heart-syncronous changes in the thoracic electrical impedance (Zo) were measured before and after the exchange transfusion. Zo consists of a parallel connection of a tissue impedance (Zt) and a blood impedance (Zb). With the aid of this model for Zo the relative variations in Zb (delta Zb/Zb) were calculated from the relative variations in Zo (delta Zo/Zo). The marked decrease of delta Zb/Zb during the experiment can only be explained by the fact that apart from the heart-synchronous changes in vascular volume the impedance changes are also caused by flow dependent changes in the electrical conductivity of blood caused by variations in orientation of the erythrocytes. PMID:558590

  18. The role of stroma in the expansion of odontogenic cysts and adenomatoid odontogenic tumor: A polarized microscopy study

    PubMed Central

    Mahajan, Aarti M.; Mahajan, Mahendra C.; Ganvir, S. M.; Hazarey, V. K.

    2013-01-01

    Objectives: To compare the polarization colors of collagen fibers of odontogenic keratocyst (OKC), radicular cyst, dentigerous cyst, and adenomatoid odontogenic tumor (AOT) with reference to their biological behavior. Study Design: Twenty cases each of OKC, radicular cyst, dentigerous cyst, and AOT were stained with picrosirius red stain and studied under polarized light. Results: A predominance of green to greenish yellow thick fibers was noted in OKC and AOT as compared to dentigerous cyst and radicular cyst. There was no significant difference between the polarization colors of the thin fibers in all the three groups. Conclusion: The stroma of OKC and AOT consists of poorly packed or pathologic collagen and plays a role in its neoplastic behavior. PMID:24082724

  19. Distribution and significance of interstitial fibrosis and stroma-infiltrating B cells in tongue squamous cell carcinoma

    PubMed Central

    LAO, XIAO-MEI; LIANG, YU-JIE; SU, YU-XIONG; ZHANG, SI-EN; ZHOU, XI; LIAO, GUI-QING

    2016-01-01

    Inflammation and desmoplasia are frequently identified in the tumor microenvironment, and have been demonstrated to be effective modulators of malignant biological events. However, the mechanisms by which the inflammatory microenvironment and interstitial fibrosis interact with one another remain to be elucidated. The present study aimed to investigate the degree of inflammation and interstitial fibrosis in tongue squamous cell carcinoma (TSCC), and how this acts to affect the outcome of TSCC. Tissue samples from 93 cases of TSCC and paired tumor-adjacent non-neoplastic tongue epithelium, as well as 14 cases of epithelial dysplasia, were used. Interstitial collagen fibers were assessed using Masson's trichrome stain. Immunohistochemical identification of cancer-associated fibroblasts (CAFs) and stroma-infiltrating B cells was performed via detection of α-smooth muscle actin (SMA), vimentin, desmin and cluster of differentiation 19 (CD19). The clinicopathological significance and overall survival of the TSCC patients were statistically analyzed. Regularly distributed CAFs and CD19+ B cells were identified in the TSCC stroma, whereas no CAFs or CD19+ B cells were observed in epithelial dysplasia samples or paired tumor-adjacent non-neoplastic tongue epithelium samples. The distribution of interstitial collagen fibers and CAFs was closely associated with the tumor stage of the primary cancer, and high levels of CD19+ B cells together with low CAF infiltration were identified to be associated with favorable prognosis in TSCC. In conclusion, the inflammatory and interstitial fibrotic microenvironments coexist in TSCC, and each has specific effects on disease outcome, individually or perhaps collectively. However, it remains to be determined exactly how the microenvironments affect one another in TSCC. PMID:26998116

  20. Deep pockets for deep seas

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    Peter Auster, a fisheries ecologist with the National Undersea Research Center in Connecticut, plans to assess degradation of the deep-shelf seafloor from bottom trawling. Magnus Ngoile, an official with Tanzania's National Environmental Management Council, will work on building capacity of poor villagers to protect their coastline. And Alison Rieser, a lawyer with the University of Maine School of Law, will produce a textbook to educate scientists on how to apply the law for marine conservation.These individuals are among 11 recipients of the Pew Charitable Trust's 10th annual marine conservation fellowships, announced on July 12. With each recipient receiving an award of $150,000, the program is the world's largest award for marine conservationists. Other 1999 recipients will be involved with areas including investigating marine pollution in the Arctic region, examining economic incentives for conservation in Baja, Mexico, and establishing a marine conservation biology training program for minority students.

  1. Markers of fibroblast-rich tumor stroma and perivascular cells in serous ovarian cancer: Inter- and intra-patient heterogeneity and impact on survival

    PubMed Central

    Corvigno, Sara; Wisman, G. Bea A.; Mezheyeuski, Artur; van der Zee, Ate G.J.; Nijman, Hans W.; Åvall-Lundqvist, Elisabeth; Östman, Arne; Dahlstrand, Hanna

    2016-01-01

    Inter- and intra-patient variations in tumor microenvironment of serous ovarian cancer are largely unexplored. We aimed to explore potential co-regulation of tumor stroma characteristics, analyze their concordance in primary and metastatic lesions, and study their impact on survival. A tissue microarray (TMA) with 186 tumors and 91 matched metastases was subjected to immunohistochemistry double staining with endothelial cell marker CD34 and fibroblast and pericyte markers α-SMA, PDGFβR and desmin. Images were digitally analyzed to yield “metrics” related to vasculature and stroma features. Intra-case analyses showed that PDGFβR in perivascular cells and fibroblasts were strongly correlated. Similar findings were observed concerning α-SMA. Most stroma characteristics showed large variations in intra-case comparisons of primary tumors and metastasis. Large PDGFβR-positive stroma fraction and high PDGFβFR positive perivascular intensity were both significantly associated with shorter survival in uni- and multi-variate analyses (HR 1.7, 95% CI 1.1-2.5; HR 1.7, 95% CI 1.1-2.8). In conclusion, we found PDGFβR- and α-SMA-expression to be largely independent of each other but concordantly activated in perivascular cells and in fibroblasts within the primary tumor. Stromal characteristics differed between primary tumors and metastases. PDGFβR in perivascular cells and in fibroblasts may be novel prognostic markers in serous ovarian cancer. PMID:26918345

  2. Probing tumor-stroma interactions and response to photodynamic therapy in a 3D pancreatic cancer-fibroblast co-culture model

    NASA Astrophysics Data System (ADS)

    Glidden, Michael D.; Massodi, Iqbal; Rizvi, Imran; Celli, Jonathan P.; Hasan, Tayyaba

    2012-02-01

    Pancreatic ductal adenocarcinoma is a lethal disease that is often unresectable by the time of diagnosis and is typically non-responsive to chemo- and radiotherapy, resulting in a five year survival of only 3%. Tumors of the pancreas are characterized by a dense fibrous stroma rich in extracellular matrix proteins, which is implicated in poor therapeutic response, though its precise roles remain poorly understood. Indeed, while the use of therapeutics that target the stroma is an emerging paradigm in the clinical management of this disease, the primary focus of such efforts is to enhance drug penetration through dense fibrous stroma and it is unclear to what extent the characteristically rigid stroma of pancreatic tumors imparts drug resistance by acting as a complex signaling partner, or merely as a physical barrier for drug delivery. Here we use 3D in vitro co-cultures of pancreatic cancer cells and normal human fibroblasts as a model system to study heterotypic interactions between these populations. Leveraging this in vitro model along with image-based methods for quantification of growth and therapeutic endpoints, we characterize these co-cultures and examine the role of verteporfin-based photodynamic therapy (PDT) for targeting tumor-fibroblast interactions in pancreatic tumors.

  3. Apparent lethal concentrations of pyrolysis products of some polymeric materials

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Marcussen, W. H.; Furst, A.; Kourtides, D. A.; Parker, J. A.

    1976-01-01

    Thirty-nine samples of polymeric materials were evaluated to determine the apparent lethal concentrations of their pyrolysis products. The materials were compared on the basis of the apparent lethal concentration for 50 percent of the test animals. Relative toxicity rankings based o apparent lethal concentration values can differ significantly depending on whether they are based on weight of sample charged or weight of sample pyrolyzed. The ranking of polyphenylene sulfide is particularly sensitive to this difference.

  4. Evaluation of Tumor-associated Stroma and Its Relationship with Tumor Hypoxia Using Dynamic Contrast-enhanced CT and (18)F Misonidazole PET in Murine Tumor Models.

    PubMed

    Koyasu, Sho; Tsuji, Yoshihisa; Harada, Hiroshi; Nakamoto, Yuji; Nobashi, Tomomi; Kimura, Hiroyuki; Sano, Kohei; Koizumi, Koji; Hamaji, Masatsugu; Togashi, Kaori

    2016-03-01

    Purpose To determine the relationship between the fractional interstitial volume (Fis), as calculated at dynamic contrast material-enhanced (DCE) computed tomography (CT), and tumor-associated stroma and to analyze its spatial relationship with tumor hypoxia in several xenograft tumor models. Materials and Methods All animal experiments were approved by the animal research committee. Mice with three different xenograft tumors (U251, CFPAC-1, and BxPC-3; n = 6, n = 8, and n = 6, respectively) underwent DCE CT then hypoxia imaging with fluorine 18 ((18)F) fluoromisonidazole (FMISO) positron emission tomography (PET) within 24 hours. Immunohistochemical analysis was performed in harvested tumors to detect hypoxia markers and to quantify microvascular and stromal density. Two DCE CT parameters (amount of interstitial space associated with the amount of stroma [Fis] and flow velocity [Fv]) were identified and quantitatively validated by using immunohistochemistry. FMISO uptake within the tumor was also assessed in relation to DCE CT parameters. Imaging and immunohistochemical parameters were assessed by using the Kruskal-Wallis test, Wilcoxon rank-sum test with Bonferroni correction, and Pearson correlation coefficient. Results Almost no α-smooth muscle actin-positive cells were found in the U251 xenograft, while abundant stroma was found in the entire BxPC-3 xenograft and in the periphery of the CFPAC-1 xenograft. Quantitative analysis showed a significant correlation (R = 0.83, P < .0001) between Fis and stromal density. FMISO uptake had a negative correlation with Fis (R = -0.58, P < .0001) and Fv (R = -0.53, P < .0001). Conclusion DCE CT can be used to quantify parameters associated with tumor-associated stroma. Tumor hypoxia was Complementarily localized in tumor-associated stroma in these models. (©) RSNA, 2015 Online supplemental material is available for this article. PMID:26393963

  5. Microsporidial spores can cross the intact Descemet membrane in deep stromal infection.

    PubMed

    Murthy, Somasheila I; Sangit, Vishram A; Rathi, Varsha M; Vemuganti, Geeta K

    2013-01-01

    We report a rare case of a deep stromal keratitis with a chronic indolent course, diagnosed as microsporidial keratitis from corneal scrapings. The patient's condition worsened despite medical therapy and penetrating keratoplasty was performed. The histopathology of the corneal tissue revealed multiple microsporidial spores in the posterior stroma and the endothelial exudates, whereas there was no clinical or histopathological breach in Descemet's membrane. This is the second report in the literature to report that micropsoridial spores can cross the intact Descemet's membrane. PMID:23580858

  6. Apparent-Strain Correction for Combined Thermal and Mechanical Testing

    NASA Technical Reports Server (NTRS)

    Johnson, Theodore F.; O'Neil, Teresa L.

    2007-01-01

    Combined thermal and mechanical testing requires that the total strain be corrected for the coefficient of thermal expansion mismatch between the strain gage and the specimen or apparent strain when the temperature varies while a mechanical load is being applied. Collecting data for an apparent strain test becomes problematic as the specimen size increases. If the test specimen cannot be placed in a variable temperature test chamber to generate apparent strain data with no mechanical loads, coupons can be used to generate the required data. The coupons, however, must have the same strain gage type, coefficient of thermal expansion, and constraints as the specimen to be useful. Obtaining apparent-strain data at temperatures lower than -320 F is challenging due to the difficulty to maintain steady-state and uniform temperatures on a given specimen. Equations to correct for apparent strain in a real-time fashion and data from apparent-strain tests for composite and metallic specimens over a temperature range from -450 F to +250 F are presented in this paper. Three approaches to extrapolate apparent-strain data from -320 F to -430 F are presented and compared to the measured apparent-strain data. The first two approaches use a subset of the apparent-strain curves between -320 F and 100 F to extrapolate to -430 F, while the third approach extrapolates the apparent-strain curve over the temperature range of -320 F to +250 F to -430 F. The first two approaches are superior to the third approach but the use of either of the first two approaches is contingent upon the degree of non-linearity of the apparent-strain curve.

  7. Apparent mass and cross-axis apparent mass of standing subjects during exposure to vertical whole-body vibration

    NASA Astrophysics Data System (ADS)

    Subashi, G. H. M. J.; Matsumoto, Y.; Griffin, M. J.

    2006-05-01

    The effects of posture and vibration magnitude on the vertical apparent mass and the fore-and-aft cross-axis apparent mass of the standing human body during exposure to vertical vibration have been investigated. Twelve male subjects were exposed to random vertical vibration over the frequency range 2.0-20 Hz at three vibration magnitudes: 0.125, 0.25 and 0.5 m s -2 rms. Subjects stood in five different postures: upright, lordotic, anterior lean, knees bent and knees more bent. The vertical acceleration at the floor and the forces in the vertical and fore-and-aft directions at the floor were used to obtain the apparent mass and the cross-axis apparent mass. The resonance frequency of the apparent mass was significantly reduced with knees bent and knees more bent postures, but there were only minor effects on the resonance frequency by changing the position of the upper body. Considerable cross-axis apparent mass, up to about 30% of the static mass of subjects, was found. The cross-axis apparent mass was influenced by all postural changes used in the study. In all postures the resonance frequencies of the apparent mass and the cross-axis apparent mass tended to decrease with increasing vibration magnitude. This nonlinear characteristic tended to be less clear in some postures in which subjects increased muscle tension.

  8. "Apparent Weight": A Concept that Is Confusing and Unnecessary

    ERIC Educational Resources Information Center

    Bartlett, Albert A.

    2010-01-01

    Two recent articles make prominent use of the concept of "apparent weight." The concept of "apparent weight" leads to two confusing inconsistencies. We need to know that with very little change in our representations, we can give our students an improved understanding of "weight" without ever having to invent the appealing but confusing concept of…

  9. 48 CFR 14.407-2 - Apparent clerical mistakes.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Apparent clerical mistakes. 14.407-2 Section 14.407-2 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES SEALED BIDDING Opening of Bids and Award of Contract 14.407-2 Apparent clerical mistakes. (a) Any...

  10. Climate control of decadal-scale increases in apparent ages of eogenetic karst spring water

    NASA Astrophysics Data System (ADS)

    Martin, Jonathan B.; Kurz, Marie J.; Khadka, Mitra B.

    2016-09-01

    Water quantity and quality in karst aquifers may depend on decadal-scale variations in recharge or withdrawal, which we hypothesize could be assessed through time-series measurements of apparent ages of spring water. We tested this hypothesis with analyses of various age tracers (3H/3He, SF6, CFC-11, CFC-12, CFC-113) and selected solute concentrations [dissolved oxygen (DO), NO3, Mg, and SO4] from 6 springs in a single spring complex (Ichetucknee springs) in northern Florida over a 16-yr period. These springs fall into two groups that reflect shallow short (Group 1) and deep long (Group 2) flow paths. Some tracer concentrations are altered, with CFC-12 and CFC-113 concentrations yielding the most robust apparent ages. These tracers show a 10-20-yr monotonic increase in apparent age from 1997 to 2013, including the flood recession that followed Tropical Storm Debby in mid-2012. This increase in age indicates most water discharged during the study period recharged the aquifer within a few years of 1973 for Group 2 springs and 1980 for Group 1 springs. Inverse correlations between apparent age and DO and NO3 concentrations reflect reduced redox state in older water. Positive correlations between apparent age and Mg and SO4 concentrations reflect increased water-rock reactions. Concentrated recharge in the decade around 1975 resulted from nearly 2 m of rain in excess of the monthly average that fell between 1960 and 2014, followed by a nearly 4 m deficit to 2014. This excess rain coincided with two major El Niño events during the maximum cool phase in the Atlantic Multidecadal Oscillation. Although regional water withdrawal increased nearly 5-fold between 1980 and 2005, withdrawals represent only 2-5% of Ichetucknee River flow and are less important than decadal-long variations in precipitation. These results suggest that groundwater management should consider climate cycles as predictive tools for future water resources.

  11. Multiple Weather Factors Affect Apparent Survival of European Passerine Birds

    PubMed Central

    Salewski, Volker; Hochachka, Wesley M.; Fiedler, Wolfgang

    2013-01-01

    Weather affects the demography of animals and thus climate change will cause local changes in demographic rates. In birds numerous studies have correlated demographic factors with weather but few of those examined variation in the impacts of weather in different seasons and, in the case of migrants, in different regions. Using capture-recapture models we correlated weather with apparent survival of seven passerine bird species with different migration strategies to assess the importance of selected facets of weather throughout the year on apparent survival. Contrary to our expectations weather experienced during the breeding season did not affect apparent survival of the target species. However, measures for winter severity were associated with apparent survival of a resident species, two short-distance/partial migrants and a long-distance migrant. Apparent survival of two short distance migrants as well as two long-distance migrants was further correlated with conditions experienced during the non-breeding season in Spain. Conditions in Africa had statistically significant but relatively minor effects on the apparent survival of the two long-distance migrants but also of a presumably short-distance migrant and a short-distance/partial migrant. In general several weather effects independently explained similar amounts of variation in apparent survival for the majority of species and single factors explained only relatively low amounts of temporal variation of apparent survival. Although the directions of the effects on apparent survival mostly met our expectations and there are clear predictions for effects of future climate we caution against simple extrapolations of present conditions to predict future population dynamics. Not only did weather explains limited amounts of variation in apparent survival, but future demographics will likely be affected by changing interspecific interactions, opposing effects of weather in different seasons, and the potential for

  12. Deep Vein Thrombosis

    MedlinePlus

    MENU Return to Web version Deep Vein Thrombosis Overview What is deep vein thrombosis? Deep vein thrombosis (also called DVT) is a blood clot in a vein deep inside your body. These clots usually occur in your leg veins. While DVT is a fairly common condition, it is ...

  13. Deep Vein Thrombosis

    MedlinePlus

    Deep vein thrombosis, or DVT, is a blood clot that forms in a vein deep in the body. Most deep vein clots occur in the ... vein swells, the condition is called thrombophlebitis. A deep vein thrombosis can break loose and cause a serious problem ...

  14. Deep Vein Thrombosis

    MedlinePlus

    Deep vein thrombosis, or DVT, is a blood clot that forms in a vein deep in the body. Most deep vein clots occur in the lower leg or ... vein swells, the condition is called thrombophlebitis. A deep vein thrombosis can break loose and cause a ...

  15. The apparent groundwater age rejuvenation caused by the human activity in Jakarta area, Indonesia

    NASA Astrophysics Data System (ADS)

    Kagabu, M.; Shimada, J.; Nakamura, T.; Delinom, R.; Taniguchi, M.

    2010-12-01

    The rapid urbanization in Jakarta area has become a serious subsurface environmental issues such as groundwater level decline and land subsidence due to excessive groundwater pumping. These problems began to emerge recently by some hydrological studies. The comparison of 14C activity between 1985 and 2008 shows the apparent groundwater age rejuvenation in the deep aquifer under the DKI Jakarta. We discussed by using a numerical groundwater flow model to evaluate the process of this rejuvenation in the urbanized area. Since the groundwater pumping was not performed intensely, the groundwater discharge flow toward the sea coast was dominant until 1983, however, this outward flux switched to intrusion flux into deeper aquifer after mid-1980s because of over-pumping in the urban area. The most largest flux among six flux directions toward the deep aquifer under the DKI Jakarta became “vertical downward flux” which means the shallower groundwater intrude into the deep one due to the excessive groundwater pumping from mid-1980s and this flux grows about 50% in 2000s. This result is consistent with the detection of chlorofluorocarbon (CFC)-12, which works as an indicator of young groundwater even in the deep groundwater. As the rejuvenation ratio “R” was determined by using 14C activity in the groundwater, R increase with the CFC-12 concentration and boths have good correlation. Besides, we estimated the “vertical downward flux” at each well's screen depth by the model estimation. The result shows that this flux has larger in the urban groundwater depression area and especially at shallower part of the deep aquifer, and it affects the magnitude of the shallow groundwater intrusion. Relationship between R and CFC-12 concentration. The diameter of cube shows the magnitude of the “vertical downward flux”

  16. Role of Human Corneal Stroma-Derived Mesenchymal-Like Stem Cells in Corneal Immunity and Wound Healing

    PubMed Central

    Veréb, Zoltán; Póliska, Szilárd; Albert, Réka; Olstad, Ole Kristoffer; Boratkó, Anita; Csortos, Csilla; Moe, Morten C.; Facskó, Andrea; Petrovski, Goran

    2016-01-01

    Corneal tissue regeneration is of crucial importance for maintaining normal vision. We aimed to isolate and cultivate human corneal stroma-derived mesenchymal stem-like cells (CSMSCs) from the central part of cadaver corneas and study their phenotype, multipotency, role in immunity and wound healing. The isolated cells grew as monolayers in vitro, expressed mesenchymal- and stemness-related surface markers (CD73, CD90, CD105, CD140b), and were negative for hematopoietic markers as determined by flow cytometry. CSMSCs were able to differentiate in vitro into fat, bone and cartilage. Their gene expression profile was closer to bone marrow-derived MSCs (BMMSCs) than to limbal epithelial stem cells (LESC) as determined by high-throughput screening. The immunosuppressive properties of CSMSCs were confirmed by a mixed lymphocyte reaction (MLR), while they could inhibit proliferation of activated immune cells. Treatment of CSMSCs by pro-inflammatory cytokines and toll-like receptor ligands significantly increased the secreted interleukin-6 (IL-6), interleukin-8 (IL-8) and C-X-C motif chemokine 10 (CXCL-10) levels, as well as the cell surface adhesion molecules. CSMSCs were capable of closing a wound in vitro under different stimuli. These cells thus contribute to corneal tissue homeostasis and play an immunomodulatory and regenerative role with possible implications in future cell therapies for treating sight-threatening corneal diseases. PMID:27195722

  17. Automated tracking of tumor-stroma morphology in microtissues identifies functional targets within the tumor microenvironment for therapeutic intervention.

    PubMed

    Åkerfelt, Malin; Bayramoglu, Neslihan; Robinson, Sean; Toriseva, Mervi; Schukov, Hannu-Pekka; Härmä, Ville; Virtanen, Johannes; Sormunen, Raija; Kaakinen, Mika; Kannala, Juho; Eklund, Lauri; Heikkilä, Janne; Nees, Matthias

    2015-10-01

    Cancer-associated fibroblasts (CAFs) constitute an important part of the tumor microenvironment and promote invasion via paracrine functions and physical impact on the tumor. Although the importance of including CAFs into three-dimensional (3D) cell cultures has been acknowledged, computational support for quantitative live-cell measurements of complex cell cultures has been lacking. Here, we have developed a novel automated pipeline to model tumor-stroma interplay, track motility and quantify morphological changes of 3D co-cultures, in real-time live-cell settings. The platform consists of microtissues from prostate cancer cells, combined with CAFs in extracellular matrix that allows biochemical perturbation. Tracking of fibroblast dynamics revealed that CAFs guided the way for tumor cells to invade and increased the growth and invasiveness of tumor organoids. We utilized the platform to determine the efficacy of inhibitors in prostate cancer and the associated tumor microenvironment as a functional unit. Interestingly, certain inhibitors selectively disrupted tumor-CAF interactions, e.g. focal adhesion kinase (FAK) inhibitors specifically blocked tumor growth and invasion concurrently with fibroblast spreading and motility. This complex phenotype was not detected in other standard in vitro models. These results highlight the advantage of our approach, which recapitulates tumor histology and can significantly improve cancer target validation in vitro. PMID:26375443

  18. Cells from the adult corneal stroma can be reprogrammed to a neuron-like cell using exogenous growth factors

    SciTech Connect

    Greene, Carol Ann Chang, Chuan-Yuan; Fraser, Cameron J.; Nelidova, Dasha E.; Chen, Jing A.; Lim, Angela; Brebner, Alex; McGhee, Jennifer; Sherwin, Trevor; Green, Colin R.

    2014-03-10

    Cells thought to be stem cells isolated from the cornea of the eye have been shown to exhibit neurogenic potential. We set out to uncover the identity and location of these cells within the cornea and to elucidate their neuronal protein and gene expression profile during the process of switching to a neuron-like cell. Here we report that every cell of the adult human and rat corneal stroma is capable of differentiating into a neuron-like cell when treated with neurogenic differentiation specifying growth factors. Furthermore, the expression of genes regulating neurogenesis and mature neuronal structure and function was increased. The switch from a corneal stromal cell to a neuron-like cell was also shown to occur in vivo in intact corneas of living rats. Our results clearly indicate that lineage specifying growth factors can affect changes in the protein and gene expression profiles of adult cells, suggesting that possibly many adult cell populations can be made to switch into another type of mature cell by simply modifying the growth factor environment. - Highlights: • Adult corneal stromal cells can differentiated into neuron-like cells. • Neuronal specification of the adult stromal cell population is stochastic. • Neuronal specification in an adult cell population can be brought about by growth factors.

  19. Role of Human Corneal Stroma-Derived Mesenchymal-Like Stem Cells in Corneal Immunity and Wound Healing.

    PubMed

    Veréb, Zoltán; Póliska, Szilárd; Albert, Réka; Olstad, Ole Kristoffer; Boratkó, Anita; Csortos, Csilla; Moe, Morten C; Facskó, Andrea; Petrovski, Goran

    2016-01-01

    Corneal tissue regeneration is of crucial importance for maintaining normal vision. We aimed to isolate and cultivate human corneal stroma-derived mesenchymal stem-like cells (CSMSCs) from the central part of cadaver corneas and study their phenotype, multipotency, role in immunity and wound healing. The isolated cells grew as monolayers in vitro, expressed mesenchymal- and stemness-related surface markers (CD73, CD90, CD105, CD140b), and were negative for hematopoietic markers as determined by flow cytometry. CSMSCs were able to differentiate in vitro into fat, bone and cartilage. Their gene expression profile was closer to bone marrow-derived MSCs (BMMSCs) than to limbal epithelial stem cells (LESC) as determined by high-throughput screening. The immunosuppressive properties of CSMSCs were confirmed by a mixed lymphocyte reaction (MLR), while they could inhibit proliferation of activated immune cells. Treatment of CSMSCs by pro-inflammatory cytokines and toll-like receptor ligands significantly increased the secreted interleukin-6 (IL-6), interleukin-8 (IL-8) and C-X-C motif chemokine 10 (CXCL-10) levels, as well as the cell surface adhesion molecules. CSMSCs were capable of closing a wound in vitro under different stimuli. These cells thus contribute to corneal tissue homeostasis and play an immunomodulatory and regenerative role with possible implications in future cell therapies for treating sight-threatening corneal diseases. PMID:27195722

  20. Abnormalities of Thymic Stroma may Contribute to Immune Dysregulation in Murine Models of Leaky Severe Combined Immunodeficiency

    PubMed Central

    Rucci, Francesca; Poliani, Pietro Luigi; Caraffi, Stefano; Paganini, Tiziana; Fontana, Elena; Giliani, Silvia; Alt, Frederick W.; Notarangelo, Luigi Daniele

    2011-01-01

    Lymphostromal cross-talk in the thymus is essential to allow generation of a diversified repertoire of T lymphocytes and to prevent autoimmunity by self-reactive T cells. Hypomorphic mutations in genes that control T cell development have been associated with immunodeficiency and immune dysregulation both in humans and in mice. We have studied T cell development and thymic stroma architecture and maturation in two mouse models of leaky severe combined immune deficiency, carrying hypomorphic mutations in rag1 and lig4 genes. Defective T cell development was associated with abnormalities of thymic architecture that predominantly affect the thymic medulla, with reduction of the pool of mature medullary thymic epithelial cells (mTECs). While the ability of mTECs to express autoimmune regulator (Aire) is preserved in mutant mice, the frequency of mature mTECs expressing Aire and tissue-specific antigens is severely reduced. Similarly, the ability of CD4+ T cells to differentiate into Foxp3+ natural regulatory T cells is preserved in rag1 and lig4 mutant mice, but their number is greatly reduced. These data indicate that hypomorphic defects in T cell development may cause defective lymphostromal cross-talk and impinge on thymic stromal cells maturation, and thus favor immune dysregulation. PMID:21822418

  1. Stroma Cell-Derived Factor-1α Signaling Enhances Calcium Transients and Beating Frequency in Rat Neonatal Cardiomyocytes

    PubMed Central

    Hadad, Ielham; Veithen, Alex; Springael, Jean–Yves; Sotiropoulou, Panagiota A.; Mendes Da Costa, Agnès; Miot, Françoise; Naeije, Robert

    2013-01-01

    Stroma cell-derived factor-1α (SDF-1α) is a cardioprotective chemokine, acting through its G-protein coupled receptor CXCR4. In experimental acute myocardial infarction, administration of SDF-1α induces an early improvement of systolic function which is difficult to explain solely by an anti-apoptotic and angiogenic effect. We wondered whether SDF-1α signaling might have direct effects on calcium transients and beating frequency. Primary rat neonatal cardiomyocytes were culture-expanded and characterized by immunofluorescence staining. Calcium sparks were studied by fluorescence microscopy after calcium loading with the Fluo-4 acetoxymethyl ester sensor. The cardiomyocyte enriched cellular suspension expressed troponin I and CXCR4 but was vimentin negative. Addition of SDF-1α in the medium increased cytoplasmic calcium release. The calcium response was completely abolished by using a neutralizing anti-CXCR4 antibody and partially suppressed and delayed by preincubation with an inositol triphosphate receptor (IP3R) blocker, but not with a ryanodine receptor (RyR) antagonist. Calcium fluxes induced by caffeine, a RyR agonist, were decreased by an IP3R blocker. Treatment with forskolin or SDF-1α increased cardiomyocyte beating frequency and their effects were additive. In vivo, treatment with SDF-1α increased left ventricular dP/dtmax. These results suggest that in rat neonatal cardiomyocytes, the SDF-1α/CXCR4 signaling increases calcium transients in an IP3-gated fashion leading to a positive chronotropic and inotropic effect. PMID:23460790

  2. Tumour imaging by the detection of fibrin clots in tumour stroma using an anti-fibrin Fab fragment

    PubMed Central

    Obonai, Toshifumi; Fuchigami, Hirobumi; Furuya, Fumiaki; Kozuka, Naoyuki; Yasunaga, Masahiro; Matsumura, Yasuhiro

    2016-01-01

    The diagnosis of early and aggressive types of cancer is important for providing effective cancer therapy. Cancer-induced fibrin clots exist only within lesions. Previously, we developed a monoclonal antibody (clone 102-10) that recognizes insoluble fibrin but not fibrinogen or soluble fibrin and confirmed that fibrin clots form continuously in various cancers. Here, we describe the development of a Fab fragment probe of clone 102-10 for tumour imaging. The distribution of 102-10 Fab was investigated in genetically engineered mice bearing pancreatic ductal adenocarcinoma (PDAC), and its effect on blood coagulation was examined. Immunohistochemical and ex vivo imaging revealed that 102-10 Fab was distributed selectively in fibrin clots in PDAC tumours 3 h after injection and that it disappeared from the body after 24 h. 102-10 Fab had no influence on blood coagulation or fibrinolysis. Tumour imaging using anti-fibrin Fab may provide a safe and effective method for the diagnosis of invasive cancers by detecting fibrin clots in tumour stroma. PMID:27009516

  3. Increased expression of the collagen internalization receptor uPARAP/Endo180 in the stroma of head and neck cancer.

    PubMed

    Sulek, Jay; Wagenaar-Miller, Rebecca A; Shireman, Jessica; Molinolo, Alfredo; Madsen, Daniel H; Engelholm, Lars H; Behrendt, Niels; Bugge, Thomas H

    2007-04-01

    Local growth, invasion, and metastasis of malignancies of the head and neck involve extensive degradation and remodeling of the underlying, collagen-rich connective tissue. Urokinase plasminogen activator receptor-associated protein (uPARAP)/Endo180 is an endocytic receptor recently shown to play a critical role in the uptake and intracellular degradation of collagen by mesenchymal cells. As a step toward determining the putative function of uPARAP/Endo180 in head and neck cancer progression, we used immunohistochemistry to determine the expression of this collagen internalization receptor in 112 human squamous cell carcinomas and 19 normal or tumor-adjacent head and neck tissue samples from the tongue, gingiva, cheek, tonsils, palate, floor of mouth, larynx, maxillary sinus, upper jaw, nasopharynx/nasal cavity, and lymph nodes. Specificity of detection was verified by staining of serial sections with two different monoclonal antibodies against two non-overlapping epitopes on uPARAP/Endo180 and by the use of isotype-matched non-immune antibodies. uPARAP/Endo180 expression was observed in stromal fibroblast-like, vimentin-positive cells. Furthermore, expression of the collagen internalization receptor was increased in tumor stroma compared with tumor-adjacent connective tissue or normal submucosal connective tissue and was most prominent in poorly differentiated tumors. These data suggest that uPARAP/Endo180 participates in the connective tissue destruction during head and neck squamous cell carcinoma progression by mediating cellular uptake and lysosomal degradation of collagen. PMID:17189524

  4. Reactive stroma component COL6A1 is upregulated in castration-resistant prostate cancer and promotes tumor growth

    PubMed Central

    Shen, Yi-Jun; Wang, Hong-Kai; Zhang, Gui-Ming; Ye, Ding-Wei

    2015-01-01

    Castration-resistant prostate cancer (CRPC) remains the most critical challenge in the clinical management of prostate cancer (PCa). Reactive stromal changes in PCa are likely involved in the emergence of CRPC. In the present study, we identified a novel oncogene termed COL6A1 which was upregulated in the reactive stroma of CRPC. We established an androgen-independent LNCaP (LNCaP-AI) cell line in steroid-reduced (SR) medium within 2 months. We examined COL6A1 expression with western blot during the LNCaP-AI induction, and studied the function of COL6A1 in vitro and in vivo. Immunohistochemical staining of COL6A1 was performed in ten pairs of androgen-sensitive PCa and CRPC samples. We demonstrated that COL6A1 expression was markedly increased in LNCaP-AI cells and CRPC tissues compared with LNCaP cells and paired androgen-sensitive PCa specimens. In vitro, COL6A1 knockdown resulted in G1-S cell cycle arrest and descended vitality. Overexpression of COL6A1 was associated with accelerated S phase entry and elevated vitality in prostate cancer cells. COL6A1 also promoted tumorigenesis of LNCaP cells in vivo. Taken together, these data suggest an important role of COL6A1 in the molecular etiology of castration-resistant prostate cancer, and support the potential use of COL6A1 in CRPC therapy. PMID:25895032

  5. Automated tracking of tumor-stroma morphology in microtissues identifies functional targets within the tumor microenvironment for therapeutic intervention

    PubMed Central

    Åkerfelt, Malin; Bayramoglu, Neslihan; Robinson, Sean; Toriseva, Mervi; Schukov, Hannu-Pekka; Härmä, Ville; Virtanen, Johannes; Sormunen, Raija; Kaakinen, Mika; Kannala, Juho; Eklund, Lauri; Heikkilä, Janne; Nees, Matthias

    2015-01-01

    Cancer-associated fibroblasts (CAFs) constitute an important part of the tumor microenvironment and promote invasion via paracrine functions and physical impact on the tumor. Although the importance of including CAFs into three-dimensional (3D) cell cultures has been acknowledged, computational support for quantitative live-cell measurements of complex cell cultures has been lacking. Here, we have developed a novel automated pipeline to model tumor-stroma interplay, track motility and quantify morphological changes of 3D co-cultures, in real-time live-cell settings. The platform consists of microtissues from prostate cancer cells, combined with CAFs in extracellular matrix that allows biochemical perturbation. Tracking of fibroblast dynamics revealed that CAFs guided the way for tumor cells to invade and increased the growth and invasiveness of tumor organoids. We utilized the platform to determine the efficacy of inhibitors in prostate cancer and the associated tumor microenvironment as a functional unit. Interestingly, certain inhibitors selectively disrupted tumor-CAF interactions, e.g. focal adhesion kinase (FAK) inhibitors specifically blocked tumor growth and invasion concurrently with fibroblast spreading and motility. This complex phenotype was not detected in other standard in vitro models. These results highlight the advantage of our approach, which recapitulates tumor histology and can significantly improve cancer target validation in vitro. PMID:26375443

  6. Stroma derived COL6A3 is a potential prognosis marker of colorectal carcinoma revealed by quantitative proteomics

    PubMed Central

    Chen, Sun-Xia; Wang, Xiao-Qing; Cui, Shu-Jian; Liu, Xiao-Hui; Jiang, Ying-Hua; Wang, Jie; Zhang, Yang; Yang, Peng-Yuan; Liu, Feng

    2015-01-01

    Colorectal cancer (CRC) represents the third most common cancer in males and second in females worldwide. Here, we performed a quantitative 8-plex iTRAQ proteomics analysis of the secreted proteins from five colonic fibroblast cultures and three colon cancer epithelial cell lines. We identified 1114 proteins at 0% FDR, including 587 potential secreted proteins. We further recognized 116 fibroblast-enriched proteins which were significantly associated with cell movement, angiogenesis, proliferation and wound healing, and 44 epithelial cell-enriched proteins. By interrogation of Oncomine database, we found that 20 and 8 fibroblast-enriched proteins were up- and downregulated in CRC, respectively. Western blots confirmed the fibroblast-specific secretion of filamin C, COL6A3, COL4A1 and spondin-2. Upregulated mRNA and stroma expression of COL6A3 in CRC, which were revealed by Oncomine analyses and tissue-microarray-immunohistochemistry, indicated poor prognosis. COL6A3 expression was significantly associated with Dukes stage, T stage, stage, recurrence and smoking status. Circulating plasma COL6A3 in CRC patients was upregulated significantly comparing with healthy peoples. Receiver operating characteristic curve analysis revealed that COL6A3 has better predictive performance for CRC with an area under the curve of 0.885 and the best sensitivity/specificity of 92.9%/81.3%. Thus we demonstrated that COL6A3 was a potential diagnosis and prognosis marker of CRC. PMID:26338966

  7. Novel protein phosphorylation site identification in spinach stroma membranes by titanium dioxide microcolumns and tandem mass spectrometry.

    PubMed

    Rinalducci, Sara; Larsen, Martin R; Mohammed, Shabaz; Zolla, Lello

    2006-04-01

    In this work, spinach stroma membrane, instead of thylakoid, has been investigated for the presence of phosphorylated proteins. We identified seven previously unknown phosphorylation sites by taking advantage of TiO(2) phosphopeptides enrichment coupled to mass spectrometric analysis. Upon illumination at 100 micromol m(-2) s(-1), two novel phosphopeptides belonging to the N-terminal region of Lhcb1 light-harvesting protein were detected: NVSSGS(p)PWYGPDR and T(p)VQSSSPWYGPDR. Moreover, three new threonine residues in CP43 (Thr-6, Thr-8, and Thr-346) and, for the first time, two amino acid residues of the N-terminus of Rieske Fe-S protein of the cytochrome b(6)f complex (Thr-2 and Ser-3) were revealed to be phosphorylated. Since Lhcb1 and CP43 have been reported as mobile proteins, it may be suggested that illumination derived phosphorylation, and consequently the addition of negatively charged groups to the protein, is a necessary condition to induce a significant protein structural change. PMID:16602705

  8. IGF-1 receptor targeted nanoparticles for image-guided therapy of stroma-rich and drug resistant human cancer

    PubMed Central

    Zhou, Hongyu; Qian, Weiping; Uckun, Fatih M.; Zhou, Zhiyang; Wang, Liya; Wang, Andrew; Mao, Hui

    2016-01-01

    Low drug delivery efficiency and drug resistance from highly heterogeneous cancer cells and tumor microenvironment represent major challenges in clinical oncology. Growth factor receptor, IGF-1R, is overexpressed in both human tumor cells and tumor associated stromal cells. The level of IGF-1R expression is further up-regulated in drug resistant tumor cells. We have developed IGF-1R targeted magnetic iron oxide nanoparticles (IONPs) carrying multiple anticancer drugs into human tumors. This IGF-1R targeted theranostic nanoparticle delivery system has an iron core for non-invasive MR imaging, amphiphilic polymer coating to ensure the biocompatibility as well as for drug loading and conjugation of recombinant human IGF-1 as targeting molecules. Chemotherapy drugs, Doxorubicin (Dox), was encapsulated into the polymer coating and/or conjugated to the IONP surface by coupling with the carboxyl groups. The ability of IGF1R targeted theranostic nanoparticles to penetrate tumor stromal barrier and enhance tumor cell killing has been demonstrated in human pancreatic cancer patient tissue derived xenograft (PDX) models. Repeated systemic administrations of those IGF-1R targeted theranostic IONP carrying Dox led to breaking the tumor stromal barrier and improved therapeutic effect. Near infrared (NIR) optical and MR imaging enabled noninvasive monitoring of nanoparticle-drug delivery and therapeutic responses. Our results demonstrated that IGF-1R targeted nanoparticles carrying multiple drugs are promising combination therapy approaches for image-guided therapy of stroma-rich and drug resistant human cancer, such as pancreatic cancer. PMID:27313332

  9. Quantitation of Murine Stroma and Selective Purification of the Human Tumor Component of Patient-Derived Xenografts for Genomic Analysis.

    PubMed

    Schneeberger, Valentina E; Allaj, Viola; Gardner, Eric E; Poirier, J T; Rudin, Charles M

    2016-01-01

    Patient-derived xenograft (PDX) mouse models are increasingly used for preclinical therapeutic testing of human cancer. A limitation in molecular and genetic characterization of PDX tumors is the presence of integral murine stroma. This is particularly problematic for genomic sequencing of PDX models. Rapid and dependable approaches for quantitating stromal content and purifying the malignant human component of these tumors are needed. We used a recently developed technique exploiting species-specific polymerase chain reaction (PCR) amplicon length (ssPAL) differences to define the fractional composition of murine and human DNA, which was proportional to the fractional composition of cells in a series of lung cancer PDX lines. We compared four methods of human cancer cell isolation: fluorescence-activated cell sorting (FACS), an immunomagnetic mouse cell depletion (MCD) approach, and two distinct EpCAM-based immunomagnetic positive selection methods. We further analyzed DNA extracted from the resulting enriched human cancer cells by targeted sequencing using a clinically validated multi-gene panel. Stromal content varied widely among tumors of similar histology, but appeared stable over multiple serial tumor passages of an individual model. FACS and MCD were superior to either positive selection approach, especially in cases of high stromal content, and consistently allowed high quality human-specific genomic profiling. ssPAL is a dependable approach to quantitation of murine stromal content, and MCD is a simple, efficient, and high yield approach to human cancer cell isolation for genomic analysis of PDX tumors. PMID:27611664

  10. Human periprostatic white adipose tissue is rich in stromal progenitor cells and a potential source of prostate tumor stroma.

    PubMed

    Ribeiro, Ricardo; Monteiro, Cátia; Silvestre, Ricardo; Castela, Angela; Coutinho, Helena; Fraga, Avelino; Príncipe, Paulo; Lobato, Carlos; Costa, Carla; Cordeiro-da-Silva, Anabela; Lopes, José Manuel; Lopes, Carlos; Medeiros, Rui

    2012-10-01

    A body of growing evidence now implicates white adipose tissue as a relevant source of stromal progenitor cells recruited to the tumor microenvironment to form supportive tumor stroma. While the role of periprostatic (PP) adipose tissue in prostate cancer progression has been barely appreciated, we sought to determine the progenitor cell population in PP adipose tissue and the association with prostate cancer. We isolated and characterized CD31(-)CD34(+)CD45(-)CD146(-) progenitor cells (adipose-derived stem cells [ASC]) in paired samples of PP and preperitoneal visceral adipose tissue from prostate tissue and peripheral blood mononuclear cells of prostate cancer and nodular prostatic hyperplasia patients. ASC were quantified by flow cytometry and confirmed through target gene expression. Here we show a significantly higher amount of ASC in PP than in visceral adipose tissue, independent of body mass index and prostatic disease. In the prostate, ASC are increased in cancer compared with prostatic nodular hyperplasia patients. Concordantly, adipsin gene (CFD) expression, which is known to be up-regulated in adipose stem cells, was overexpressed in PP adipose tissue, in the prostate of cancer patients and in prostate CD31(-)CD34(+)CD45(-)CD146(-) sorted cells. ASC were found at higher levels in the blood of prostate cancer patients simultaneously overweight/obese. Present findings indicate that PP adipose tissue is a reservoir of progenitor cells with the potential to migrate towards prostate tumors, although its clinical significance merits further evaluation. PMID:23038706

  11. Stroma derived COL6A3 is a potential prognosis marker of colorectal carcinoma revealed by quantitative proteomics.

    PubMed

    Qiao, Jie; Fang, Cai-Yun; Chen, Sun-Xia; Wang, Xiao-Qing; Cui, Shu-Jian; Liu, Xiao-Hui; Jiang, Ying-Hua; Wang, Jie; Zhang, Yang; Yang, Peng-Yuan; Liu, Feng

    2015-10-01

    Colorectal cancer (CRC) represents the third most common cancer in males and second in females worldwide. Here, we performed a quantitative 8-plex iTRAQ proteomics analysis of the secreted proteins from five colonic fibroblast cultures and three colon cancer epithelial cell lines. We identified 1114 proteins at 0% FDR, including 587 potential secreted proteins. We further recognized 116 fibroblast-enriched proteins which were significantly associated with cell movement, angiogenesis, proliferation and wound healing, and 44 epithelial cell-enriched proteins. By interrogation of Oncomine database, we found that 20 and 8 fibroblast-enriched proteins were up- and downregulated in CRC, respectively. Western blots confirmed the fibroblast-specific secretion of filamin C, COL6A3, COL4A1 and spondin-2. Upregulated mRNA and stroma expression of COL6A3 in CRC, which were revealed by Oncomine analyses and tissue-microarray-immunohistochemistry, indicated poor prognosis. COL6A3 expression was significantly associated with Dukes stage, T stage, stage, recurrence and smoking status. Circulating plasma COL6A3 in CRC patients was upregulated significantly comparing with healthy peoples. Receiver operating characteristic curve analysis revealed that COL6A3 has better predictive performance for CRC with an area under the curve of 0.885 and the best sensitivity/specificity of 92.9%/81.3%. Thus we demonstrated that COL6A3 was a potential diagnosis and prognosis marker of CRC. PMID:26338966

  12. Overcoming a species-specificity barrier in development of an inhibitory antibody targeting a modulator of tumor stroma

    PubMed Central

    Grossman, Iris; Ilani, Tal; Fleishman, Sarel Jacob; Fass, Deborah

    2016-01-01

    The secreted disulfide catalyst Quiescin sulfhydryl oxidase-1 (QSOX1) affects extracellular matrix organization and is overexpressed in various adenocarcinomas and associated stroma. Inhibition of extracellular human QSOX1 by a monoclonal antibody decreased tumor cell migration in a cell co-culture model and hence may have therapeutic potential. However, the species specificity of the QSOX1 monoclonal antibody has been a setback in assessing its utility as an anti-metastatic agent in vivo, a common problem in the antibody therapy industry. We therefore used structurally guided engineering to expand the antibody species specificity, improving its affinity toward mouse QSOX1 by at least four orders of magnitude. A crystal structure of the re-engineered variant, complexed with its mouse antigen, revealed that the antibody accomplishes dual-species targeting through altered contacts between its heavy and light chains, plus replacement of bulky aromatics by flexible side chains and versatile water-bridged polar interactions. In parallel, we produced a surrogate antibody targeting mouse QSOX1 that exhibits a new QSOX1 inhibition mode. This set of three QSOX1 inhibitory antibodies is compatible with various mouse models for pre-clinical trials and biotechnological applications. In this study we provide insights into structural blocks to cross-reactivity and set up guideposts for successful antibody design and re-engineering. PMID:26819240

  13. Possible contribution of prostatic anterior fibromuscular stroma to age-related urinary disturbance in reference to pressure-flow study.

    PubMed

    Ukimura, Osamu; Iwata, Tsuyoshi; Ushijima, So; Suzuki, Kei; Honjo, Hisashi; Okihara, Koji; Mizutani, Yoichi; Kawauchi, Akihiro; Miki, Tsuneharu

    2004-05-01

    Recently, we reported that the anterior fibromuscular stroma (AFMS) of the prostate has significant different innervation compared with the other glandular regions of the prostate. In healthy volunteers (n = 12) using transrectal ultrasound (US), or TRUS, monitoring during voiding, we observed dynamic change (p < 0.0001) of the thickness of the AFMS during voiding. The aim of this study was to reveal the possible functional contribution of the AFMS to micturition, as well as the age-related voiding dysfunction. In the patients (n = 56) with voiding dysfunction who underwent both pressure-flow study (PFS) for determining obstruction and TRUS monitoring during voiding, we measured the ultrasonic dynamic change of the lower urinary tract during voiding. In old men with voiding dysfunction, ultrasonic measurements of dynamic change in the AFMS (p < 0.01) as well as the opening urethra (p < 0.05) could contribute to diagnosing of the anatomical localization of obstructive lesions. The poor movement of AFMS could account for the age-related urinary disturbance in the patients without benign prostatic enlargement and without bladder neck obstruction. PMID:15183221

  14. Stroma cell-derived factor-1α signaling enhances calcium transients and beating frequency in rat neonatal cardiomyocytes.

    PubMed

    Hadad, Ielham; Veithen, Alex; Springael, Jean-Yves; Sotiropoulou, Panagiota A; Mendes Da Costa, Agnès; Miot, Françoise; Naeije, Robert; De Deken, Xavier; Entee, Kathleen Mc

    2013-01-01

    Stroma cell-derived factor-1α (SDF-1α) is a cardioprotective chemokine, acting through its G-protein coupled receptor CXCR4. In experimental acute myocardial infarction, administration of SDF-1α induces an early improvement of systolic function which is difficult to explain solely by an anti-apoptotic and angiogenic effect. We wondered whether SDF-1α signaling might have direct effects on calcium transients and beating frequency.Primary rat neonatal cardiomyocytes were culture-expanded and characterized by immunofluorescence staining. Calcium sparks were studied by fluorescence microscopy after calcium loading with the Fluo-4 acetoxymethyl ester sensor. The cardiomyocyte enriched cellular suspension expressed troponin I and CXCR4 but was vimentin negative. Addition of SDF-1α in the medium increased cytoplasmic calcium release. The calcium response was completely abolished by using a neutralizing anti-CXCR4 antibody and partially suppressed and delayed by preincubation with an inositol triphosphate receptor (IP3R) blocker, but not with a ryanodine receptor (RyR) antagonist. Calcium fluxes induced by caffeine, a RyR agonist, were decreased by an IP3R blocker. Treatment with forskolin or SDF-1α increased cardiomyocyte beating frequency and their effects were additive. In vivo, treatment with SDF-1α increased left ventricular dP/dtmax.These results suggest that in rat neonatal cardiomyocytes, the SDF-1α/CXCR4 signaling increases calcium transients in an IP3-gated fashion leading to a positive chronotropic and inotropic effect. PMID:23460790

  15. Suppression of CD51 in pancreatic stellate cells inhibits tumor growth by reducing stroma and altering tumor-stromal interaction in pancreatic cancer.

    PubMed

    Horioka, Kohei; Ohuchida, Kenoki; Sada, Masafumi; Zheng, Biao; Moriyama, Taiki; Fujita, Hayato; Manabe, Tatsuya; Ohtsuka, Takao; Shimamoto, Masaya; Miyazaki, Tetsuyuki; Mizumoto, Kazuhiro; Oda, Yoshinao; Nakamura, Masafumi

    2016-04-01

    Pancreatic stellate cells (PSCs) enhance the malignant behavior of pancreatic cancer by interacting with cancer cells and producing extracellular matrix (ECM). To date, several stroma-targeted therapies for pancreatic cancer have been attempted, but these therapies are still not in practical use. Integrins expressed in stromal cells are involved in fibrosis of several organs, as well as promoting tumor malignancy. We investigated whether CD51, also known as integrin αV, expressed in PSCs was associated with stromal formation of pancreatic cancer and enhancement of tumor malignancy. We also assessed the effects of suppression of CD51 in PSCs on pancreatic cancer. Immunohistochemistry for CD51 in resected pancreatic cancer tissues showed that high expression of CD51 in the tumor stroma was associated with lymph node metastasis (P=0.025), positive pathologic margin (P=0.025), and shorter patient survival times (P=0.043). Lentivirus-mediated short hairpin RNA knockdown of CD51 decreased the proliferation and migration of PSCs. Quantitative real-time polymerase chain reaction showed that expression levels of genes related with ECM and tumor-stromal interactions were decreased by CD51 knockdown in PSCs. In a co-implantation model of pancreatic cancer cells and PSCs, tumor growth in vivo was inhibited by CD51 knockdown in PSCs (P<0.05). We also found reduced tumor stroma and decreased proliferation of cancer cells in implanted cancer tissues with CD51-silenced PSCs (P<0.05). Our results showed that CD51 expression in pancreatic cancer stroma is associated with enhanced tumor malignancy and that CD51 may be a potential therapeutic target for pancreatic cancer. PMID:26846197

  16. Toward automatic segmentation and quantification of tumor and stroma in whole-slide images of H and E stained rectal carcinomas

    NASA Astrophysics Data System (ADS)

    Geessink, Oscar G. F.; Baidoshvili, Alexi; Freling, Gerard; Klaase, Joost M.; Slump, Cornelis H.; van der Heijden, Ferdinand

    2015-03-01

    Visual estimation of tumor and stroma proportions in microscopy images yields a strong, Tumor-(lymph)Node- Metastasis (TNM) classification-independent predictor for patient survival in colorectal cancer. Therefore, it is also a potent (contra)indicator for adjuvant chemotherapy. However, quantification of tumor and stroma through visual estimation is highly subject to intra- and inter-observer variability. The aim of this study is to develop and clinically validate a method for objective quantification of tumor and stroma in standard hematoxylin and eosin (H and E) stained microscopy slides of rectal carcinomas. A tissue segmentation algorithm, based on supervised machine learning and pixel classification, was developed, trained and validated using histological slides that were prepared from surgically excised rectal carcinomas in patients who had not received neoadjuvant chemotherapy and/or radiotherapy. Whole-slide scanning was performed at 20× magnification. A total of 40 images (4 million pixels each) were extracted from 20 whole-slide images at sites showing various relative proportions of tumor and stroma. Experienced pathologists provided detailed annotations for every extracted image. The performance of the algorithm was evaluated using cross-validation by testing on 1 image at a time while using the other 39 images for training. The total classification error of the algorithm was 9.4% (SD = 3.2%). Compared to visual estimation by pathologists, the algorithm was 7.3 times (P = 0.033) more accurate in quantifying tissues, also showing 60% less variability. Automatic tissue quantification was shown to be both reliable and practicable. We ultimately intend to facilitate refined prognostic stratification of (colo)rectal cancer patients and enable better personalized treatment.

  17. 48 CFR 14.407-2 - Apparent clerical mistakes.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... clerical mistakes. (a) Any clerical mistake, apparent on its face in the bid, may be corrected by the... bid and a copy of the verification to the duplicate bid. Correction shall not be made on the face...

  18. Apparent Ionic Charge in Electrolyte and Polyelectrolyte Solutions

    ERIC Educational Resources Information Center

    Magdelenat, H.; And Others

    1978-01-01

    Compares average displacements of charged particles under thermal motion alone with those obtained by the action of an external electric field to develop a concept of "apparent charge" to approximate actual structural charge in an electrolyte solution. (SL)

  19. Cystic tumor of the liver without ovarian-like stroma or bile duct communication: two case reports and a review of the literature.

    PubMed

    Kishida, Norihiro; Shinoda, Masahiro; Masugi, Yohei; Itano, Osamu; Fujii-Nishimura, Yoko; Ueno, Akihisa; Kitago, Minoru; Hibi, Taizo; Abe, Yuta; Yagi, Hiroshi; Tanimoto, Akihiro; Tanabe, Minoru; Sakamaoto, Michiie; Kitagawa, Yuko

    2014-01-01

    We report two cases of cystic neoplasm of the liver with mucinous epithelium in which both ovarian-like stroma and bile duct communication were absent. The first case was a 41-year-old woman. She underwent right trisegmentectomy due to a multilocular cystic lesion, 15 cm in diameter, with papillary nodular components in the medial segment and right lobe. Histologically, arborizing papillae were seen in the papillary lesion. The constituent neoplastic cells had sufficient cytoarchitectural atypia to be classified as high-grade dysplasia. The second case was a 60-year-old woman. She underwent left lobectomy due to a unilocular cystic lesion, 17 cm in diameter, in the left lobe. Histologically, the cyst wall was lined by low columnar epithelia with slight cellular atypia. In both cases, neither ovarian-like stroma nor bile duct communications were found throughout the resected specimen. According to the most recent World Health Organization (WHO) classification in 2010, cystic tumors of the liver with mucinous epithelium are classified as mucinous cystic neoplasms when ovarian-like stromata are found, and as intraductal papillary neoplasm of bile duct when bile duct communication exists. Therefore, we diagnosed the cystic tumors as 'biliary cystadenoma' according to the past WHO classification scheme from 2000. We believe that the combined absence of both ovarian-like stroma and bile duct communication is possible in mucinous cystic tumors of the liver. Herein, we have described the clinicopathologic features of the two cases and reviewed past cases in the literature. PMID:25047921

  20. An Improved Comprehensive Model for the Apparent Viscosity of Blood

    NASA Astrophysics Data System (ADS)

    Jacobitz, Frank; Anderson, Spencer

    2008-11-01

    An improved comprehensive model for the apparent viscosity of blood is developed and used in simulations of the microcirculation in capillary bundles of rat spinotrapezius muscle fascia. In the microcirculation, the apparent viscosity of blood depends on the local vessel diameter, hematocrit, and shear rate. The proposed comprehensive model extends the apparent viscosity model developed by Pries, Secomb, Gaehtgens, and Gross (Circulation Research, 67, 826-834, 1990), which describes the effect of vessel diameter and hematocrit on the apparent viscosity. A shear thinning term is developed using the experimental data of Lipowsky, Usami, and Chien (Microvascular Research, 19, 297-319, 1980). Curve fits of this data can be combined with equations given in the Pries et al. work to create a system of equations that can be used to find the shear thinning factor. The simulations based on the improved apparent viscosity model use realistic vessel topology for the microvasculature, reconstructed from microscope images of tissue samples, and consider passive and active vessel properties. The numerical method is based on a Hagen-Poiseuille balance in the microvessels and a sparse matrix solver is used to obtain the solution. It was found that the inclusion of the shear factor decreases the overall flowrate in the capillary bundle. Many vessel connections in the fascia are characterized by relatively low shear rates and therefore increased apparent viscosity.

  1. The Molecular Signature of the Stroma Response in Prostate Cancer-Induced Osteoblastic Bone Metastasis Highlights Expansion of Hematopoietic and Prostate Epithelial Stem Cell Niches

    PubMed Central

    Secondini, Chiara; Wetterwald, Antoinette; Schwaninger, Ruth; Fleischmann, Achim; Raffelsberger, Wolfgang; Poch, Olivier; Delorenzi, Mauro; Temanni, Ramzi; Mills, Ian G.; van der Pluijm, Gabri; Thalmann, George N.; Cecchini, Marco G.

    2014-01-01

    The reciprocal interaction between cancer cells and the tissue-specific stroma is critical for primary and metastatic tumor growth progression. Prostate cancer cells colonize preferentially bone (osteotropism), where they alter the physiological balance between osteoblast-mediated bone formation and osteoclast-mediated bone resorption, and elicit prevalently an osteoblastic response (osteoinduction). The molecular cues provided by osteoblasts for the survival and growth of bone metastatic prostate cancer cells are largely unknown. We exploited the sufficient divergence between human and mouse RNA sequences together with redefinition of highly species-specific gene arrays by computer-aided and experimental exclusion of cross-hybridizing oligonucleotide probes. This strategy allowed the dissection of the stroma (mouse) from the cancer cell (human) transcriptome in bone metastasis xenograft models of human osteoinductive prostate cancer cells (VCaP and C4-2B). As a result, we generated the osteoblastic bone metastasis-associated stroma transcriptome (OB-BMST). Subtraction of genes shared by inflammation, wound healing and desmoplastic responses, and by the tissue type-independent stroma responses to a variety of non-osteotropic and osteotropic primary cancers generated a curated gene signature (“Core” OB-BMST) putatively representing the bone marrow/bone-specific stroma response to prostate cancer-induced, osteoblastic bone metastasis. The expression pattern of three representative Core OB-BMST genes (PTN, EPHA3 and FSCN1) seems to confirm the bone specificity of this response. A robust induction of genes involved in osteogenesis and angiogenesis dominates both the OB-BMST and Core OB-BMST. This translates in an amplification of hematopoietic and, remarkably, prostate epithelial stem cell niche components that may function as a self-reinforcing bone metastatic niche providing a growth support specific for osteoinductive prostate cancer cells. The induction of this

  2. The molecular signature of the stroma response in prostate cancer-induced osteoblastic bone metastasis highlights expansion of hematopoietic and prostate epithelial stem cell niches.

    PubMed

    Özdemir, Berna C; Hensel, Janine; Secondini, Chiara; Wetterwald, Antoinette; Schwaninger, Ruth; Fleischmann, Achim; Raffelsberger, Wolfgang; Poch, Olivier; Delorenzi, Mauro; Temanni, Ramzi; Mills, Ian G; van der Pluijm, Gabri; Thalmann, George N; Cecchini, Marco G

    2014-01-01

    The reciprocal interaction between cancer cells and the tissue-specific stroma is critical for primary and metastatic tumor growth progression. Prostate cancer cells colonize preferentially bone (osteotropism), where they alter the physiological balance between osteoblast-mediated bone formation and osteoclast-mediated bone resorption, and elicit prevalently an osteoblastic response (osteoinduction). The molecular cues provided by osteoblasts for the survival and growth of bone metastatic prostate cancer cells are largely unknown. We exploited the sufficient divergence between human and mouse RNA sequences together with redefinition of highly species-specific gene arrays by computer-aided and experimental exclusion of cross-hybridizing oligonucleotide probes. This strategy allowed the dissection of the stroma (mouse) from the cancer cell (human) transcriptome in bone metastasis xenograft models of human osteoinductive prostate cancer cells (VCaP and C4-2B). As a result, we generated the osteoblastic bone metastasis-associated stroma transcriptome (OB-BMST). Subtraction of genes shared by inflammation, wound healing and desmoplastic responses, and by the tissue type-independent stroma responses to a variety of non-osteotropic and osteotropic primary cancers generated a curated gene signature ("Core" OB-BMST) putatively representing the bone marrow/bone-specific stroma response to prostate cancer-induced, osteoblastic bone metastasis. The expression pattern of three representative Core OB-BMST genes (PTN, EPHA3 and FSCN1) seems to confirm the bone specificity of this response. A robust induction of genes involved in osteogenesis and angiogenesis dominates both the OB-BMST and Core OB-BMST. This translates in an amplification of hematopoietic and, remarkably, prostate epithelial stem cell niche components that may function as a self-reinforcing bone metastatic niche providing a growth support specific for osteoinductive prostate cancer cells. The induction of this

  3. Proteomics of the human endometrial glandular epithelium and stroma from the proliferative and secretory phases of the menstrual cycle.

    PubMed

    Hood, Brian L; Liu, Baoquan; Alkhas, Addie; Shoji, Yutaka; Challa, Rusheeswar; Wang, Guisong; Ferguson, Susan; Oliver, Julie; Mitchell, Dave; Bateman, Nicholas W; Zahn, Christopher M; Hamilton, Chad A; Payson, Mark; Lessey, Bruce; Fazleabas, Asgerally T; Maxwell, G Larry; Conrads, Thomas P; Risinger, John I

    2015-04-01

    Despite its importance in reproductive biology and women's health, a detailed molecular-level understanding of the human endometrium is lacking. Indeed, no comprehensive studies have been undertaken to elucidate the important protein expression differences between the endometrial glandular epithelium and surrounding stroma during the proliferative and midsecretory phases of the menstrual cycle. We utilized laser microdissection to harvest epithelial cells and stromal compartments from proliferative and secretory premenopausal endometrial tissue and performed a global, quantitative mass spectrometry-based proteomics analysis. This analysis identified 1224 total proteins from epithelial cells, among which 318 were differentially abundant between the proliferative and secretory phases (q < 0.05), and 1005 proteins from the stromal compartments, 19 of which were differentially abundant between the phases (q < 0.05). Several proteins were chosen for validation by immunohistochemistry in an independent set of uterine tissues, including carboxypeptidase M, tenascin C, neprilysin, and ectonucleotide pyrophosphatase/phosphodiesterase family member 3 (ENPP3). ENPP3, which was elevated in epithelial glandular cells in the secretory phase, was confirmed to be elevated in midsecretory-phase baboon uterine lavage samples and also observed to have an N-linked glycosylated form that was not observed in the proliferative phase. This study provides a detailed view into the global proteomic alterations of the epithelial cells and stromal compartments of the cycling premenopausal endometrium. These proteomic alterations during endometrial remodeling provide a basis for numerous follow-up investigations on the function of these differentially regulated proteins and their role in reproductive biology and endometrial pathologies. PMID:25695723

  4. Blood-Based Biomarkers Are Associated with Disease Recurrence and Survival in Gastrointestinal Stroma Tumor Patients after Surgical Resection

    PubMed Central

    Stotz, Michael; Liegl-Atzwanger, Bernadette; Posch, Florian; Mrsic, Edvin; Thalhammer, Michael; Stojakovic, Tatjana; Bezan, Angelika; Pichler, Martin; Gerger, Armin; Szkandera, Joanna

    2016-01-01

    Background Inflammatory blood count biomarkers may improve recurrence risk stratification and inform long-term prognosis of cancer patients. Here, we quantify the prognostic impact of blood-based biomarkers on recurrence risk and long-term survival in a large cohort of gastrointestinal stroma tumor (GIST) patients after curative surgery. Methods One-hundred-forty-nine consecutive GIST patients were followed-up for a median period of 4.8 years. Local recurrence, distant metastasis, and death occurred in 9, 21, and 31 patients, respectively. Time-to-event and competing risk analysis were applied to study the association between haemoglobin (Hb) level, white blood cell count (WBC), neutrophil/lymphocyte ratio (NLR), derived NLR (dNLR), lymphocyte/monocyte ratio (LMR), and platelet/lymphocyte ratio (PLR) with risk of local or distant recurrence (RR), recurrence free survival (RFS), and overall survival (OS). Results A low Hb (p = 0.029), and elevations in the parameters WBC (p = 0.004), NLR (p = 0.015) and dNLR (p = 0.037) were associated with a poor OS in GIST patients in multivariate analysis. Moreover, a low Hb (p = 0.049) and an elevated WBC (p = 0.001), NLR (p = 0.007), dNLR (p = 0.043) and PLR (p = 0.024) were independently associated with decreased RFS after adjusting for Miettinen score. However, only an increase of dNLR/NLR showed a significant association to higher RR (p = 0.048). Inclusion of NLR or PLR to Miettinen risk score did not reasonably improve the clinical risk prediction of 2-year RFS. Conclusion Low Hb, elevated WBC, elevated dNLR, and elevated PLR are independent prognostic factors for a worse clinical outcome in GIST patients after curative resection. PMID:27454486

  5. Taoism and Deep Ecology.

    ERIC Educational Resources Information Center

    Sylvan, Richard; Bennett, David

    1988-01-01

    Contrasted are the philosophies of Deep Ecology and ancient Chinese. Discusses the cosmology, morality, lifestyle, views of power, politics, and environmental philosophies of each. Concludes that Deep Ecology could gain much from Taoism. (CW)

  6. Deep Ecology and Subjectivity.

    ERIC Educational Resources Information Center

    Foley, Grover

    1988-01-01

    Describes Deep Ecology and criticizes its limitations. Discusses mysticism, the bomb, freedom, subjectivity and power as they are addressed by Deep Ecology. Stresses the need to teach ecological balance. (CW)

  7. Deep vein thrombosis - discharge

    MedlinePlus

    You were treated for deep venous thrombosis (DVT). This is a condition in which a blood clot forms in a vein that is not on ... especially if it gets worse upon taking a deep breath in You cough up blood

  8. Deep venous thrombosis

    MedlinePlus

    Deep venous thrombosis is a condition that occurs when a blood clot forms in a vein deep inside a part ... M, et al. Executive Summary: Antithrombotic Therapy and Prevention of Thrombosis. 9th ed. American College of Chest ...

  9. Preventing Deep Vein Thrombosis

    MedlinePlus

    ... Patient Education FAQs Preventing Deep Vein Thrombosis Patient Education Pamphlets - Spanish Preventing Deep Vein Thrombosis FAQ174, August 2011 PDF ... Your Practice Patient Safety & Quality Payment Reform (MACRA) Education & Events Annual ... Pamphlets Teen Health About ACOG About Us Leadership & ...

  10. Deep Vein Thrombosis

    MedlinePlus

    ... page from the NHLBI on Twitter. What Is Deep Vein Thrombosis? Español Deep vein thrombosis (throm-BO-sis), or DVT, is a blood clot that forms in a vein deep in the body. Blood clots occur when blood ...

  11. Deep Web video

    SciTech Connect

    None Available

    2009-06-01

    To make the web work better for science, OSTI has developed state-of-the-art technologies and services including a deep web search capability. The deep web includes content in searchable databases available to web users but not accessible by popular search engines, such as Google. This video provides an introduction to the deep web search engine.

  12. Deep Web video

    ScienceCinema

    None Available

    2012-03-28

    To make the web work better for science, OSTI has developed state-of-the-art technologies and services including a deep web search capability. The deep web includes content in searchable databases available to web users but not accessible by popular search engines, such as Google. This video provides an introduction to the deep web search engine.

  13. Deep Space Telecommunications

    NASA Technical Reports Server (NTRS)

    Kuiper, T. B. H.; Resch, G. M.

    2000-01-01

    The increasing load on NASA's deep Space Network, the new capabilities for deep space missions inherent in a next-generation radio telescope, and the potential of new telescope technology for reducing construction and operation costs suggest a natural marriage between radio astronomy and deep space telecommunications in developing advanced radio telescope concepts.

  14. Fungal interface keratitis by Candida orthopsilosis following deep anterior lamellar keratoplasty

    PubMed Central

    Wessel, Julia M; Bachmann, Björn O; Meiller, Ralph; Kruse, Friedrich E

    2013-01-01

    A 39-year-old male patient underwent uncomplicated deep anterior lamellar keratoplasty due to keratoconus. On day 5 after surgery, small whitish infiltrates developed in the corneal interface. The diagnosis of fungal keratitis was made when the culture medium of the graft grew Candida after the surgical intervention. Despite intensive antimycotic treatment and irrigation of the interface, the infiltrates persisted and eventually enlarged. Therefore, revision surgery with penetrating keratoplasty was performed. Microbiological analysis showed Candida orthopsilosis in the culture of the excised graft button. Histopathological staining of the excised graft showed periodic acid–Schiff-positive and Grocott methenamine silver-positive clusters of yeast between Descemet's membrane and the deep corneal stroma with focal perforations through Descemet's membrane. The treatment of mycotic keratitis caused by C orthopsilosis is challenging. Antimycotic treatment was unsuccessful in this case. Progression of the keratitis and perforation of Descemet's membrane suggest that early surgical intervention by penetrating keratoplasty is required. PMID:23349184

  15. EFFECT OF PRESSURE ON THE APPARENT SPECIFIC VOLUME OF PROTEINS*

    PubMed Central

    Fahey, Paul F.; Kupke, D. W.; Beams, J. W.

    1969-01-01

    The magnetic densimeter has been employed to measure the densities and apparent specific volumes of certain proteins in aqueous solutions as a function of pressure. The method gave values in satisfactory agreement with those found in the literature for aqueous electrolyte solutions. A change in apparent specific volume of the monomeric proteins, ribonuclease and turnip yellow mosaic virus and its capsid protein, at pressures up to 400 atmospheres at 20°C was not observed within the precision of the measurements. Also, no change in the apparent specific volume of tobacco mosaic virus protein was observed as a function of these pressures whether the protein was predominantly in the polymerized or unpolymerized state. The magnetic densimeter was found to be a convenient instrument for measuring compressibilities of very small samples of solutions. PMID:5257142

  16. Apparent Stress and Centroid Time Shift: Oceanic vs Continental Earthquakes

    NASA Astrophysics Data System (ADS)

    Pérez-Campos, X.; McGuire, J. J.; Beroza, G. C.

    2001-12-01

    Seismic energy is a broadband measure of the strength of radiation in an earthquake. Slow earthquakes, for which the rupture velocity and/or the rise time, are longer than usual, are characterized by having anomalously little seismic radiation at high frequencies. Thus, the apparent stress, the ratio of the seismic energy to the seismic moment times the shear modulus, is a natural measure of whether or not an earthquake is slow. Slow events have long been associated with oceanic tranforms. It is unusual then, that in a global study of strike slip earthquakes, Choy and Boatwright (1995) found that oceanic transform events have values of apparent stress approximately an order of magnitude higher than normal and reverse faulting events. Part of this discrepancy appears to be a selection bias in that some slow events that are deficient in high frequency energy are not routinely reported by the NEIC. We find that the average apparent stress for oceanic ridge-ridge transform events is lower than for continental strike-slip events. Another possible measure of whether or not an earthquake is slow is the centroid time shift. We find a population of slow events on oceanic transforms with both a very low apparent stress and a very large centroid time shift, as might be expected. Continental transform events that have similarly low apparent stress do not show the same correlation with centroid time shift. It is not clear why these two populations differ, but by comparing spectra for different events with low apparent stress but different centroid time shift, we should be able to test possible sources of the differences, such as variations in the spectral shape for continental versus oceanic events, that could explain these observations.

  17. On apparent temperature in low-frequency Alfvenic turbulence

    SciTech Connect

    Nariyuki, Yasuhiro

    2012-08-15

    Low-frequency, parallel propagating Alfvenic turbulence in collisionless plasmas is theoretically studied. Alfvenic turbulence is derived as an equilibrium state (Beltrami field) in the magnetohydrodynamic equations with the pressure anisotropy and multi-species of ions. It is shown that the conservation of the total 'apparent temperature' corresponds to the Bernoulli law. A simple model of the radially expanding solar wind including Alfvenic turbulence is also discussed. The conversion of the wave energy in the 'apparent temperature' into the 'real temperature' is facilitated with increasing radial distance.

  18. General theory for apparent energy distribution of sea waves

    NASA Astrophysics Data System (ADS)

    Wu, Ke-Jian; Sun, Fu

    1997-12-01

    This paper presents a general theory for the apparent energy distribution of sea waves. Using the joint distribution of wave periods and heights proposed earlier by the second author, the authors define the generalized apparent energy distribution and derive the analytical form of the so called generalized outer frequency spectrum or nth-order frequency spectrum. Some possible relationships between it and the Fourier frequency spectrum are discussed. It is shown that the widely used Bretschneider spectrum can be easily obtained from the above definition and that generalized outer frequency spectrum has equilibrium range with exponent -( n+3) whose upper limit is -3.

  19. Surgical treatment for apparent early stage endometrial cancer

    PubMed Central

    2014-01-01

    Most experts would agree that the standard surgical treatment for endometrial cancer includes a hysterectomy and bilateral salpingo-oophorectomy; however, the benefit of full surgical staging with lymph node dissection in patients with apparent early stage disease remains a topic of debate. Recent prospective data and advances in laparoscopic techniques have transformed this disease into one that can be successfully managed with minimally invasive surgery. This review will discuss the current surgical management of apparent early stage endometrial cancer and some of the new techniques that are being incorporated. PMID:24596812

  20. Directional seismic reflectivity of deep crust: Examples from southeastern US and central Anatolia

    SciTech Connect

    Coruh, C.; Costain, J.K. . Dept. of Geological Sciences)

    1994-03-01

    Apparent reflectivity of seismic reflection sections is used to elaborate on rheology of deep crustal reflectors. Because of physical anisotropy and other conditions that affect the amplitudes of seismic reflections, the apparent seismic reflectivity can vary considerably depending on the direction of the seismic profile. Crustal seismic refection data from the southeastern US, Virginia, South Carolina and Georgia, and from central Anatolia are presented to demonstrate the variation in the apparent seismic reflectivity of the crust in seismic sections.

  1. Climate Influence on Deep Sea Populations

    PubMed Central

    Company, Joan B.; Puig, Pere; Sardà, Francesc; Palanques, Albert; Latasa, Mikel; Scharek, Renate

    2008-01-01

    Dynamics of biological processes on the deep-sea floor are traditionally thought to be controlled by vertical sinking of particles from the euphotic zone at a seasonal scale. However, little is known about the influence of lateral particle transport from continental margins to deep-sea ecosystems. To address this question, we report here how the formation of dense shelf waters and their subsequent downslope cascade, a climate induced phenomenon, affects the population of the deep-sea shrimp Aristeus antennatus. We found evidence that strong currents associated with intense cascading events correlates with the disappearance of this species from its fishing grounds, producing a temporary fishery collapse. Despite this initial negative effect, landings increase between 3 and 5 years after these major events, preceded by an increase of juveniles. The transport of particulate organic matter associated with cascading appears to enhance the recruitment of this deep-sea living resource, apparently mitigating the general trend of overexploitation. Because cascade of dense water from continental shelves is a global phenomenon, we anticipate that its influence on deep-sea ecosystems and fisheries worldwide should be larger than previously thought. PMID:18197243

  2. Bias of apparent tracer ages in heterogeneous environments.

    PubMed

    McCallum, James L; Cook, Peter G; Simmons, Craig T; Werner, Adrian D

    2014-01-01

    The interpretation of apparent ages often assumes that a water sample is composed of a single age. In heterogeneous aquifers, apparent ages estimated with environmental tracer methods do not reflect mean water ages because of the mixing of waters from many flow paths with different ages. This is due to nonlinear variations in atmospheric concentrations of the tracer with time resulting in biases of mixed concentrations used to determine apparent ages. The bias of these methods is rarely reported and has not been systematically evaluated in heterogeneous settings. We simulate residence time distributions (RTDs) and environmental tracers CFCs, SF6 , (85) Kr, and (39) Ar in synthetic heterogeneous confined aquifers and compare apparent ages to mean ages. Heterogeneity was simulated as both K-field variance (σ(2) ) and structure. We demonstrate that an increase in heterogeneity (increase in σ(2) or structure) results in an increase in the width of the RTD. In low heterogeneity cases, widths were generally on the order of 10 years and biases generally less than 10%. In high heterogeneity cases, widths can reach 100 s of years and biases can reach up to 100%. In cases where the temporal variations of atmospheric concentration of individual tracers vary, different patterns of bias are observed for the same mean age. We show that CFC-12 and CFC-113 ages may be used to correct for the mean age if analytical errors are small. PMID:23550995

  3. 20 CFR 653.113 - Processing apparent violations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Processing apparent violations. 653.113 Section 653.113 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR SERVICES OF THE EMPLOYMENT SERVICE SYSTEM Services for Migrant and Seasonal Farmworkers (MSFWs) §...

  4. 20 CFR 653.113 - Processing apparent violations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Processing apparent violations. 653.113 Section 653.113 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR SERVICES OF THE EMPLOYMENT SERVICE SYSTEM Services for Migrant and Seasonal Farmworkers (MSFWs) §...

  5. Apparent horizons in D-dimensional Robinson-Trautman spacetime

    SciTech Connect

    Svitek, Otakar

    2009-05-01

    We derive the higher dimensional generalization of Penrose-Tod equation describing apparent horizons in Robinson-Trautman spacetimes. New results concerning the existence and uniqueness of its solutions in four dimensions are proven. Namely, previous results of Tod [1] are generalized to nonvanishing cosmological constant.

  6. The horizontal apparent mass of the standing human body

    NASA Astrophysics Data System (ADS)

    Matsumoto, Y.; Griffin, M. J.

    2011-06-01

    The driving-point dynamic responses of standing people (e.g. their mechanical impedance or apparent mass) influence their dynamic interactions with structures on which they are supported. The apparent mass of the standing body has been reported previously for vertical excitation but not for lateral or fore-and-aft excitation. Twelve standing male subjects were exposed to fore-and-aft and lateral random vibration over the frequency range 0.1-5.0 Hz for 180 s at four vibration magnitudes: 0.016, 0.0315, 0.063, and 0.125 m s -2 rms. With lateral excitation at 0.063 m s -2 rms, subjects also stood with three separations of the feet. The dynamic forces measured at the driving-point in each of the three translational axes (i.e. fore-and-aft, lateral and vertical) showed components not linearly related to the input vibration, and not seen in previous studies with standing subjects exposed to vertical vibration or seated subjects exposed to vertical or horizontal vibration. A principal peak in the lateral apparent mass around 0.5 Hz tended to decrease in both frequency and magnitude with increasing magnitude of vibration and increase with increasing separation of the feet. The fore-and-aft apparent mass appeared to peak at a frequency lower than the lowest frequency used in the study.

  7. Increasing Range Of Apparent Depth In A Stereoscopic Display

    NASA Technical Reports Server (NTRS)

    Busquets, Anthony M.; Parrish, Russell V.; Williams, Steven P.

    1995-01-01

    Optical configuration conceived for increasing range of apparent depth provided by stereoscopic display system, without imposing concomitant reduction in field of view. Observer wears shuttered goggles synchronized with alternating left- and right-eye views on display. However, instead of looking directly at display screen, observer looks at screen via reflection in mirror collimating light emitted by screen.

  8. Discovery of an Apparent Nova in M81

    NASA Astrophysics Data System (ADS)

    Hornoch, K.; Alfaro, M. Diaz; Ordonez-Etxeberria, I.; Vaduvescu, O.

    2015-01-01

    We report the discovery of an apparent nova in M81 on a co-added 1600-s narrow-band H-alpha CCD image taken with the 2.5-m Isaac Newton Telescope (INT) + WFC at La Palma under ~2.4" seeing on 2015 Jan. 15.126 UT.

  9. Spatial Attention and Audiovisual Interactions in Apparent Motion

    ERIC Educational Resources Information Center

    Sanabria, Daniel; Soto-Faraco, Salvador; Spence, Charles

    2007-01-01

    In this study, the authors combined the cross-modal dynamic capture task (involving the horizontal apparent movement of visual and auditory stimuli) with spatial cuing in the vertical dimension to investigate the role of spatial attention in cross-modal interactions during motion perception. Spatial attention was manipulated endogenously, either…

  10. Changes in apparent duration follow shifts in perceptual timing.

    PubMed

    Bruno, Aurelio; Ayhan, Inci; Johnston, Alan

    2015-01-01

    It is well established that the apparent duration of moving visual objects is greater at higher as compared to slower speeds. Here we report the effects of acceleration and deceleration on the perceived duration of a drifting grating with average speed kept constant (10°/s).For acceleration, increasing the speed range progressively reduced perceived duration. The magnitude of apparent duration compression was determined by speed rather than temporal frequency and was proportional to speed range (independent of standard duration) rather than acceleration. The perceived duration reduction was also proportional to the standard length. The effects of increases and decreases in speed were highly asymmetric. Reducing speed through the interval induced a moderate increase in perceived duration. These results could not be explained by changes in apparent onset or offset or differences in perceived average speed between intervals containing increasing speed and intervals containing decreasing speed. Paradoxically, for intervals combining increasing speed and decreasing speed, compression only occurred when increasing speed occurred in the second half of the interval. We show that this pattern of results in the duration domain was concomitant with changes in the reported direction of apparent motion of Gaussian blobs, embedded in intervals of increasing or decreasing speed, that could be predicted from adaptive changes in the temporal impulse response function. We detected similar changes after flicker adaptation, suggesting that the two effects might be linked through changes in the temporal tuning of visual filters. PMID:26024450

  11. Apparent digestible energy value of crude glycerol fed to pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The apparent digestible energy of crude glycerol, a co-product of biodiesel production, was determined in two studies conducted at the Iowa State University Swine Nutrition Research Farm, Ames, IA. In the first study, 24 barrows with an average body weight of 11.0 kg were fed 376 g/d of a basal corn...

  12. Estimating depth to argillic soil horizons using apparent electrical conductivity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maps of apparent electrical conductivity (ECa) of the soil profile are widely used in precision agriculture practice and research. A number of ECa sensors are commercially available, each with a unique response function (i.e., the relative contribution of soil at each depth to the integrated ECa rea...

  13. Apparent damage accumulation in cancellous bone using neural networks.

    PubMed

    Hambli, Ridha

    2011-08-01

    In this paper, a neural network model is developed to simulate the accumulation of apparent fatigue damage of 3D trabecular bone architecture at a given bone site during cyclic loading. The method is based on five steps: (i) performing suitable numerical experiments to simulate fatigue accumulation of a 3D micro-CT trabecular bone samples taken from proximal femur for different combinations of loading conditions; (ii) averaging the sample outputs in terms of apparent damage at whole specimen level based on local tissue damage; (iii) preparation of a proper set of corresponding input-output data to train the network to identify apparent damage evolution; (iv) training the neural network based on the results of step (iii); (v) application of the neural network as a tool to estimate rapidly the apparent damage evolution at a given bone site. The proposed NN model can be incorporated into finite element codes to perform fatigue damage simulation at continuum level including some morphological factors and some bone material properties. The proposed neural network based multiscale approach is the first model, to the author's knowledge, that incorporates both finite element analysis and neural network computation to rapidly simulate multilevel fatigue of bone. This is beneficial to develop enhanced finite element models to investigate the role of damage accumulation on bone damage repair during remodelling. PMID:21616468

  14. An Apparent Paradox: Catt's Anomaly

    ERIC Educational Resources Information Center

    Pieraccini, M.; Selleri, S.

    2013-01-01

    Catt's anomaly is a sort of "thought experiment" (a "gedankenexperiment") where electrons seem to travel at the speed of light. Although its author argued with conviction for many years, it has a clear and satisfactory solution and it can be considered indubitably just an apparent paradox. Nevertheless, it is curious and…

  15. Discovery of an Apparent Nova in M31

    NASA Astrophysics Data System (ADS)

    Hornoch, K.; Kucakova, H.

    2016-03-01

    We report the discovery of an apparent nova in M31 on a co-added 720-s R-band CCD frame taken on 2016 Mar. 6.806 UT with the 0.65-m telescope at Ondrejov. The object designated PNV J00421951+4111137 is located at R.A. = 0h42m19s.51, Decl.

  16. Clinicopathologic Characteristics of 29 Invasive Carcinomas Arising in 178 Pancreatic Mucinous Cystic Neoplasms With Ovarian-type Stroma

    PubMed Central

    Jang, Kee-Taek; Park, Sang Mo; Basturk, Olca; Bagci, Pelin; Bandyopadhyay, Sudeshna; Stelow, Edward B.; Walters, Dustin M.; Choi, Dong Wook; Choi, Seoung Ho; Heo, Jin Seok; Sarmiento, Juan M.; Reid, Michelle D.; Adsay, Volkan

    2015-01-01

    Information on the clinicopathologic characteristics of invasive carcinomas arising from mucinous cystic neoplasms (MCNs) is limited, because in many early studies they were lumped and analyzed together with noninvasive MCNs. Even more importantly, many of the largest prior studies did not require ovarian-type stroma (OTS) for diagnosis. We analyzed 178 MCNs, all strictly defined by the presence of OTS, 98% of which occurred in perimenopausal women (mean age, 47 y) and arose in the distal pancreas. Twenty-nine (16%) patients had associated invasive carcinoma, and all were female with a mean age of 53. Invasion was far more common in tumors with grossly visible intracystic papillary nodule formation ≥ 1.0 cm (79.3% vs. 8.7%, P = 0.000) as well as in larger tumors (mean cyst size: 9.4 vs. 5.4 cm, P = 0.006); only 4/29 (14%) invasive carcinomas occurred in tumors that were < 5 cm; however, none were < 3 cm. Increased serum CA19-9 level (> 37 U/L) was also more common in the invasive tumors (64% vs. 23%, P = 0.011). Most invasive carcinomas (79%) were of tubular type, and the remainder (5 cases) were mostly undifferentiated carcinoma (2, with osteoclast-like giant cells), except for 1 with papillary features. Interestingly, there were no colloid carcinomas; 2 patients had nodal metastasis at the time of diagnosis, and both died of disease at 10 and 35 months, respectively. While noninvasive MCNs had an excellent prognosis (100% at 5 y), tumors with invasion often had an aggressive clinical course with 3- and 5-year survival rates of 44% and 26%, respectively (P = 0.000). The pT2 (> 2 cm) invasive tumors had a worse prognosis than pTl (≤ 2 cm) tumors (P = 0.000), albeit 3 patients with T1a (< 0.5 cm) disease also died of disease. In conclusion, invasive carcinomas are seen in 16% of MCNs and are mostly of tubular (pancreatobiliary) type; colloid carcinoma is not seen in MCNs. Serum CA19-9 is often higher in invasive carcinomas, and invasion is typically seen in OTS

  17. Spatiotemporal averaging of perceived brightness along an apparent motion trajectory.

    PubMed

    Nagai, Takehiro; Beer, R Dirk; Krizay, Erin A; Macleod, Donald I A

    2011-01-01

    Objects are critical functional units for many aspects of visual perception and recognition. Many psychophysical experiments support the concept of an "object file" consisting of characteristics attributed to a single object on the basis of successive views of it, but there has been little evidence that object identity influences apparent brightness and color. In this study, we investigated whether the perceptual identification of successive flashed stimuli as views of a single moving object could affect brightness perception. Our target stimulus was composed of eight wedge-shaped sectors. The sectors were presented successively at different inter-flash intervals along an annular trajectory. At inter-flash intervals of around 100 ms, the impression was of a single moving object undergoing long-range apparent motion. By modulating the luminance between successive views, we measured the perception of luminance modulation along the trajectory of this long-range apparent motion. At the inter-flash intervals where the motion perception was strongest, the luminance difference was perceptually underestimated, and forced-choice luminance discrimination thresholds were elevated. Moreover, under such conditions, it became difficult for the observer to correctly associate or "bind" spatial positions and wedge luminances. These results indicate that the different luminances of wedges that were perceived as a single object were averaged along its apparent motion trajectory. The large spatial step size of our stimulus makes it unlikely that the results could be explained by averaging in a low-level mechanism that has a compact spatiotemporal receptive field (such as V1 and V2 neurons); higher level global motion or object mechanisms must be invoked to account for the averaging effect. The luminance averaging and the ambiguity of position-luminance "binding" suggest that the visual system may evade some of the costs of rapidly computing apparent brightness by adopting the

  18. Small-angle neutron scattering study of the ultrastructure of chloroplast thylakoid membranes - periodicity and structural flexibility of the stroma lamellae.

    PubMed

    Posselt, Dorthe; Nagy, Gergely; Kirkensgaard, Jacob J K; Holm, Jens K; Aagaard, Thomas H; Timmins, Peter; Rétfalvi, Eszter; Rosta, László; Kovács, László; Garab, Győző

    2012-08-01

    The multilamellar organization of freshly isolated spinach and pea chloroplast thylakoid membranes was studied using small-angle neutron scattering. A broad peak at ~0.02Å(-1) is ascribed to diffraction from domains of ordered, unappressed stroma lamellae, revealing a repeat distance of 294ű7Å in spinach and 345ű11Å in pea. The peak position and hence the repeat distance of stroma lamellae is strongly dependent on the osmolarity and the ionic strength of the suspension medium, as demonstrated by varying the sorbitol and the Mg(++)-concentration in the sample. For pea thylakoid membranes, we show that the repeat distance decreases when illuminating the sample with white light, in accordance with our earlier results on spinach, also regarding the observation that addition of an uncoupler prohibits the light-induced structural changes, a strong indication that these changes are driven by the transmembrane proton gradient. We show that the magnitude of the shrinkage is strongly dependent on light intensity and that the repeat distance characteristic of the dark state after illumination is different from the initial dark state. Prolonged strong illumination leads to irreversible changes and swelling as reflected in increased repeat distances. The observed reorganizations are discussed within the frames of the current structural models of the granum-stroma thylakoid membrane assembly and the regulatory mechanisms in response to variations in the environmental conditions in vivo. This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: from Natural to Artificial. PMID:22306529

  19. Temperature and depth mediate resource competition and apparent competition between Mysis diluviana and kokanee.

    PubMed

    Schoen, Erik R; Beauchamp, David A; Buettner, Anna R; Overman, Nathanael C

    2015-10-01

    In many food webs, species in similar trophic positions can interact either by competing for resources or boosting shared predators (apparent competition), but little is known about how the relative strengths of these interactions vary across environmental gradients. Introduced Mysis diluviana shrimp interact with planktivorous fishes such as kokanee salmon (lacustrine Oncorhynchus nerka) through both of these pathways, and effective management depends on understanding which interaction is more limiting under different conditions. An "environmental matching" hypothesis predicts the ecological impacts of Mysis are maximized under cool conditions near its thermal optimum. In addition, we hypothesized Mysis is more vulnerable to predation by lake trout in relatively shallow waters, and therefore Mysis enhances lake trout density and limits kokanee through apparent competition more strongly in shallower habitats. We tested whether these hypotheses could explain food web differences between two connected lake basins, one relatively shallow and the other extremely deep. The shallower basin warmed faster, thermally excluded Mysis from surface waters for 75% longer, and supported 2.5-18 times greater seasonal production of cladoceran zooplankton than the deeper basin, standardized by surface area. Mysis consumed 14-22% less zooplankton in the shallower basin, and lower ratios of total planktivore consumption to zooplankton production (C:P) indicated less potential for resource competition with kokanee, consistent with environmental matching. Lake trout diets contained more Mysis in the shallower basin and at shallower sampling sites within both basins. The catch rate of lake trout was seven times greater and the predation risk for kokanee was 4-5 times greater in the shallower basin than in the deeper basin, consistent with stronger apparent competition in shallower habitats. Understanding how the strengths of these interactions are mediated by temperature and depth would

  20. Extracting a low-dimensional description of multiple gene expression datasets reveals a potential driver for tumor-associated stroma in ovarian cancer.

    PubMed

    Celik, Safiye; Logsdon, Benjamin A; Battle, Stephanie; Drescher, Charles W; Rendi, Mara; Hawkins, R David; Lee, Su-In

    2016-01-01

    Patterns in expression data conserved across multiple independent disease studies are likely to represent important molecular events underlying the disease. We present the INSPIRE method to infer modules of co-expressed genes and the dependencies among the modules from multiple expression datasets that may contain different sets of genes. We show that INSPIRE infers more accurate models than existing methods to extract low-dimensional representation of expression data. We demonstrate that applying INSPIRE to nine ovarian cancer datasets leads to a new marker and potential driver of tumor-associated stroma, HOPX, followed by experimental validation. The implementation of INSPIRE is available at http://inspire.cs.washington.edu . PMID:27287041

  1. Apparent Diffusion Coefficient analysis of encephalitis: A comparative study with topographic evaluation and conventional MRI findings

    PubMed Central

    Katirag, Ahmet; Beker-Acay, Mehtap; Unlu, Ebru; Demirbas, Hayri; Demirturk, Nese

    2016-01-01

    Objective: Our purpose was to reveal the efficiency of diffusion weighted imaging (DWI) in the diagnosis of encephalitis, and to determine the relation between the apparent diffusion coefficient (ADC) values, the onset of the clinical symptoms, and the lesion extent. Methods: Conventional magnetic resonance imaging (MRI) was performed in 17 patients with encephalitis diagnosed on the basis of laboratory, clinical and radiologic findings during 2009 and 2015. Based on the duration between the onset of the symptoms and the brain MRI findings, the patients were divided into three groups. ADC values of the encephalitis lesion, the lesions’ topographic analysis score, deep gray matter involvement, patients’ clinical situation and the duration of the arrival to the clinic was examined. Results: Mean ADC values were 0,988±0,335 x10-3 mm2/s in group I (0-2 days), 1,045±0,347 x10-3 mm2/s in Group-II (3-7 days), 1,451±0,225 x10-3 mm2/s in Group-III (8 days and over). The relation between the ADC values and the duration of the arrival, topographic analysis score, the relation between the patients’ clinical situation and the deep gray matter involvement were found to be statistically significant. The deep gray matter involvement was demonstrated more clearly by FLAIR images when compared with DWI. Conclusion: Conventional MRI sequences may be insufficient in showing the encephalitis lesion. DWI must be added to the imaging modalities immediately in the cases suspected of having encephalitis. PMID:27375722

  2. The deep space network

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Presented is Deep Space Network (DSN) progress in flight project support, tracking and data acquisition (TDA) research and technology, network engineering, hardware and software implementation, and operations.

  3. The deep space network

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Summaries are given of Deep Space Network progress in flight project support, tracking and data acquisition research and technology, network engineering, hardware and software implementation, and operations.

  4. Deep space antennas

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    Three 26-m tracking antennas operated by the NASA Deep Space Network at Goldstone, Calif.; Madrid, Spain; and near Canberra, Australia, will cease operations on Dec. 1, 1981. The stations will continue to operate 64-m and 34-m deep space tracking antennas. Ending operation of the 26-m antennas will cause a reduction of about 30%; of the Deep Space Network tracking and data acquisition capability. This means less support for NASA planetary spacecraft. Currently, the Deep Space Network is supporting Voyagers 1 and 2, Helios 1, the Mars Viking 1 Lander and Pioneers 6 through 12.

  5. A deep reef in deep trouble

    USGS Publications Warehouse

    Menza, Charles; Kendall, M.; Rogers, C.; Miller, J.

    2007-01-01

    The well-documented degradation of shallower reefs which are often closer to land and more vulnerable to pollution, sewage and other human-related stressors has led to the suggestion that deeper, more remote offshore reefs could possibly serve as sources of coral and fish larvae to replenish the shallower reefs. Yet, the distribution, status, and ecological roles of deep (>30 m) Caribbean reefs are not well known. In this report, an observation of a deep reef which has undergone a recent extensive loss of coral cover is presented. In stark contrast to the typical pattern of coral loss in shallow reefs, the deeper corals were most affected. This report is the first description of such a pattern of coral loss on a deep reef.

  6. Wavelength dependence of the apparent diameter of retinal blood vessels.

    PubMed

    Park, Robert; Twietmeyer, Karen; Chipman, Russell; Beaudry, Neil; Salyer, David

    2005-04-01

    Imaging of retinal blood vessels may assist in the diagnosis and monitoring of diseases such as glaucoma, diabetic retinopathy, and hypertension. However, close examination reveals that the contrast and apparent diameter of vessels are dependent on the wavelength of the illuminating light. In this study multispectral images of large arteries and veins within enucleated swine eyes are obtained with a modified fundus camera by use of intravitreal illumination. The diameters of selected vessels are measured as a function of wavelength by cross-sectional analysis. A fixed scale with spectrally independent dimension is placed above the retina to isolate the chromatic effects of the imaging system and eye. Significant apparent differences between arterial and venous diameters are found, with larger diameters observed at shorter wavelengths. These differences are due primarily to spectral absorption in the cylindrical blood column. PMID:15813519

  7. Information Limits on Identification of Natural Surfaces by Apparent Colour

    PubMed Central

    Foster, David H.; Nascimento, Sérgio M. C.; Amano, Kinjiro

    2007-01-01

    By adaptational and other mechanisms, the visual system can compensate for moderate changes in the colour of the illumination on a scene. Although the colours of most surfaces are perceived to be constant (“colour constancy”), some are not. The effect of these residual colour changes on the ability of observers to identify surfaces by their apparent colour was determined theoretically from high-resolution hyperspectral images of natural scenes under different daylights with correlated colour temperatures 4300 K, 6500 K, and 25000 K. Perceived differences between colours were estimated with an approximately uniform colour-distance measure. The information preserved under illuminant changes increased with the number of surfaces in the sample, but was limited to a relatively low asymptotic value, indicating the importance of physical factors in constraining identification by apparent colour. PMID:16178155

  8. Color analysis of apparently achromatic automotive paints by visible microspectrophotometry.

    PubMed

    Kopchick, Kristin A; Bommarito, Christopher R

    2006-03-01

    Chromatic secondary pigments are utilized in achromatic automotive paints to create unique paint systems. These pigments may not be observable in reflected light; however, utilizing visible microspectrophotometry (MSP) discriminating data may be gathered. This study analyzed 160 apparently achromatic automotive paints via this technique for spectral evidence of secondary pigmentation. These results were compared with visual observations made via polarizing light microscopy. Positive spectral results were attained in approximately 25% of the black and gray/silver topcoat sample sets, whereas the white topcoat and gray undercoat set yielded no probative spectral data. The black sample set did yield several samples that produced spectral evidence of pigmentation when no visual chromatic data was observed. The results of this study suggest that paint analysis schemes should incorporate visible MSP for apparently achromatic black and gray/silver paint samples. PMID:16566767

  9. Mass density at geostationary orbit and apparent mass refilling

    NASA Astrophysics Data System (ADS)

    Denton, R. E.; Takahashi, Kazue; Amoh, Justice; Singer, H. J.

    2016-04-01

    We used the inferred equatorial mass density ρm,eq based on measurements of Alfvén wave frequencies measured by the GOES satellites during 1980-1991 in order to construct a number of different models of varying complexity for the equatorial mass density at geostationary orbit. The most complicated models are able to account for 66% of the variance with a typical variation from actual values of a factor of 1.56. The factors that influenced ρm,eq in the models were, in order of decreasing importance, the F10.7 EUV index, magnetic local time, the solar wind dynamic pressure Pdyn, the phase of the year, and the solar wind BZ (GSM Z direction). During some intervals, some of which were especially geomagnetically quiet, ρm,eq rose to values that were significantly higher than those predicted by our models. For 10 especially quiet intervals, we examined long-term (>1 day) apparent refilling, the increase in ρm,eq at a fixed location. We found that the behavior of ρm,eq varies for different events. In some cases, there is significant apparent refilling, whereas in other cases ρm,eq stays the same or even decreases slightly. Nevertheless, we showed that on average, ρm,eq increases exponentially during quiet intervals. There is variation of apparent refilling with respect to the phase of the solar cycle. On the third day of apparent refilling, ρm,eq has on average a similar value at solar maximum or solar minimum, but at solar maximum, ρm,eq begins with a larger value and rises relatively less than at solar minimum.

  10. Discovery of an Apparent Nova in M31

    NASA Astrophysics Data System (ADS)

    Hornoch, K.; Carey, G.; Kucakova, H.

    2015-11-01

    We report the discovery of an apparent nova in M31 on a co-added 900-s R-band CCD frame taken on 2015 Nov. 22.718 UT with the 0.65-m telescope at Ondrejov and independently on two 600-s luminance filter CCD frames taken on Nov. 22.756 UT with the 0.20-m telescope at Bromsgrove.

  11. Apparent Viscosity of Active Nematics in Poiseuille Flow

    NASA Astrophysics Data System (ADS)

    Cui, Zhenlu; Su, Jianbing; Zeng, Xiaoming

    2015-09-01

    A Leslie-Erickson continuum hydrodynamic for flowing active nematics has been used to characterize active particle systems such as bacterial suspensions. The behavior of such a system under a plane pressure-driven Poiseuille flow is analyzed. When plate anchoring is tangential and normal, we find the apparent viscosity formula indicating a significant difference between tangential anchoring and normal anchoring conditions for both active rodlike and discoid nematics.

  12. Infants' perception of subjective contours from apparent motion.

    PubMed

    Yamaguchi, Masami K; Kanazawa, So; Okamura, Hiromi

    2008-01-01

    We examined infants' perception of subjective contours in Subjective-Contour-from-Apparent-Motion (SCAM) stimuli [e.g., Cicerone, C. M., Hoffman, D. D., Gowdy, P. D., & Kim, J. S. (1995). The perception of color from motion. Perception & Psychophysics, 57, 761-777] using the preferential looking technique. The SCAM stimulus is composed of random dots which are assigned two different colors. Circular region assigned one color moved apparently, keeping all dots' location unchanged. In the SCAM stimulus, adults can perceive subjective color spreading and subjective contours in apparent motion (http://c-faculty.chuo-u.ac.jp/ approximately ymasa/okamura/ibd_demo.html). In the present study, we conducted two experiments by using this type of SCAM stimulus. A total of thirty-six 3-8-month-olds participated. In experiment 1, we presented two stimuli to the infants side by side: a SCAM stimulus consisting of different luminance, and a non-SCAM stimulus consisting of isoluminance dots. The results indicated that the 5-8-month-olds showed preference for the SCAM stimuli. In experiments 2 and 3, we confirmed that the infants' preference for the SCAM stimulus was not generated by the local difference and local change made by luminance of dots but by the subjective contours. These results suggest that 5-8-month-olds were able to perceive subjective contours in the SCAM stimuli. PMID:17727955

  13. Social sampling explains apparent biases in judgments of social environments.

    PubMed

    Galesic, Mirta; Olsson, Henrik; Rieskamp, Jörg

    2012-12-01

    How people assess their social environments plays a central role in how they evaluate their life circumstances. Using a large probabilistic national sample, we investigated how accurately people estimate characteristics of the general population. For most characteristics, people seemed to underestimate the quality of others' lives and showed apparent self-enhancement, but for some characteristics, they seemed to overestimate the quality of others' lives and showed apparent self-depreciation. In addition, people who were worse off appeared to enhance their social position more than those who were better off. We demonstrated that these effects can be explained by a simple social-sampling model. According to the model, people infer how others are doing by sampling from their own immediate social environments. Interplay of these sampling processes and the specific structure of social environments leads to the apparent biases. The model predicts the empirical results better than alternative accounts and highlights the importance of considering environmental structure when studying human cognition. PMID:23104680

  14. Self-reversal and apparent magnetic excursions in Arctic sediments

    NASA Astrophysics Data System (ADS)

    Channell, J. E. T.; Xuan, C.

    2009-06-01

    The Arctic oceans have been fertile ground for the recording of apparent excursions of the geomagnetic field, implying that the high latitude field had unusual characteristics at least over the last 1-2 Myrs. Alternating field demagnetization of the natural remanent magnetization (NRM) of Core HLY0503-6JPC from the Mendeleev Ridge (Arctic Ocean) implies the presence of primary magnetizations with negative inclination apparently recording excursions in sediments deposited during the Brunhes Chron. Thermal demagnetization, on the other hand, indicates the presence of multiple (often anti-parallel) magnetization components with negative inclination components having blocking temperatures predominantly, but not entirely, below ~ 350 °C. Thermo-magnetic tests, X-ray diffraction (XRD) and scanning electron microscopy (SEM) indicate that the negative inclination components are carried by titanomaghemite, presumably formed by seafloor oxidation of titanomagnetite. The titanomaghemite apparently carries a chemical remanent magnetization (CRM) that is partially self-reversed relative to the detrital remanent magnetization (DRM) carried by the host titanomagnetite. The partial self-reversal could have been accomplished by ionic ordering during oxidation, thereby changing the balance of the magnetic moments in the ferrimagnetic sublattices.

  15. Corrections of surface fissure effect on apparent resistivity measurements

    NASA Astrophysics Data System (ADS)

    Gance, J.; Sailhac, P.; Malet, J.-P.

    2015-02-01

    Electrical resistivity tomography (ERT) is a useful tool to detect and track water flow paths in the subsoil. However, measurements are strongly affected by subsurface heterogeneities such as fissures of different sizes and genesis (shrinking-swelling, macropores and deformation). In this work, we focus on surface fissures characterized by dimensions lower than the interelectrode spacing and correct their effect on apparent resistivity pseudo-sections by incorporating fissure geometry in the topography. We show that fissures with depths greater than 0.10 times the interelectrode spacing for a dipole-dipole array and equal to 0.16 for the gradient array and the Wenner-Schlumberger arrays create significant anomalies (greater than 5 per cent) in the pseudo-section. Surface fissure widths and dip angles have little effect with respect to the fissure depths which can increase the apparent resistivity up to 200 per cent. The clogging of the fissures with water or soil material decreases the anomaly effect linearly with the percentage of filling. The correction of apparent resistivity values is possible for relatively simple fissure geometries and only requires a manual survey of the surface fissures. It allows to improve the quality of the inverted resistivity section by mitigating the inversion artefacts and therefore a better interpretation.

  16. Apparent directional spectral emissivity determination of semitransparent materials

    NASA Astrophysics Data System (ADS)

    Chun-Yang, Niu; Hong, Qi; Ya-Tao, Ren; Li-Ming, Ruan

    2016-04-01

    An inverse estimation method and corresponding measurement system are developed to measure the apparent spectral directional emissivities of semitransparent materials. The normal spectral emissivity and transmissivity serve as input for the inverse analysis. Consequently, the refractive index and absorption coefficient of the semitransparent material could be retrieved by using the pseudo source adding method as the forward method and the stochastic particle swarm optimization algorithm as the inverse method. Finally, the arbitrary apparent spectral directional emissivity of semitransparent material is estimated by using the pseudo source adding method given the retrieval refractive index and absorption coefficient. The present system has the advantage of a simple experimental structure, high accuracy, and excellent capability to measure the emissivity in an arbitrary direction. Furthermore, the apparent spectral directional emissivity of sapphire at 773 K is measured by using this system in a spectral range of 3 μm–12 μm and a viewing range of 0°–90°. The present method paves the way for a new directional spectral emissivity measurement strategy. Project supported by the National Natural Science Foundation of China (Grant Nos. 51476043 and 51576053) and the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (Grant No. 51421063).

  17. Tissue Proteomics Reveals Differential and Compartment-Specific Expression of the Homologs Transgelin and Transgelin-2 in Lung Adenocarcinoma and Its Stroma

    PubMed Central

    Rho, Jung-hyun; Roehrl, Michael H. A.; Wang, Julia Y.

    2009-01-01

    Discovery of tissue-specific biomarkers for human cancer is crucial for early diagnosis and molecular understanding of the disease. To overcome the limitations posed by the large dynamic concentration range and compositional complexity of tissue biomacromolecules, we applied heparin affinity fractionation for proteomic enrichment. Comparing the proteomes of five paired samples of normal lung and pulmonary adenocarcinoma tissue by 2-D difference gel electrophoresis, 14 spots were found to be differentially expressed. From these candidate spots, three proteins overexpressed in cancer were identified by mass spectrometry as transgelin (TAGLN, SM22-α, WS3-10), transgelin-2 (TAGLN2), and cyclophilin A (PPIA). Quantitative RT-PCR indicated that both TAGLN2 and PPIA were upregulated at transcriptional level. Differential protein expression levels were validated by Western blot analysis using an independent set of 10 paired lung adenocarcinoma samples. Using immunohistochemistry on human tissue sections, we discovered that overexpression of TAGLN was strictly localized to the tumor-induced reactive myofibroblastic stromal tissue compartment, whereas overexpression of TAGLN2 was exclusively localized to the neoplastic glandular compartment. Thus, the highly homologous protein pair TAGLN and TAGLN2 displayed mutually exclusive, compartment-specific cell type expression regulation in tumor stroma vs. neoplastic epithelial cells. Our data further suggest that TGLN may be a marker of active stromal remodeling in the vicinity of invasive carcinomas. It may shed light on mechanisms of tumor-stroma interaction and could be useful for early diagnosis, treatment guidance, and treatment response monitoring. PMID:19848416

  18. Separation of light-induced linear, cyclic and stroma-sourced electron fluxes to P700+ in cucumber leaf discs after pre-illumination at a chilling temperature.

    PubMed

    Fan, Da-Yong; Hope, Alexander B; Jia, Husen; Chow, Wah Soon

    2008-06-01

    Pre-illumination of cucumber leaf discs at 4 degrees C with low-irradiance white light (i) led to a marked decrease in the extent of photo-oxidation of P700 (the special chlorophyll pair in the PSI reaction center) in actinic light at room temperature and (ii) hastened the post-illumination re-reduction of P700+. Quantifying the linear, cyclic and stroma-sourced electron fluxes to P700+ in two actinic light regimes, we found that there was no increase in cyclic or linear electron fluxes to account for these changes. Rather, we observed a decrease in the maximum extent of P700 photo-oxidation assayed by a strong flash superimposed on continuous, background light of wavelength 723 nm, which we interpret to represent a loss of stable charge separation in PSI due to enhanced charge recombination as a result of the pre-illumination treatment. The funneling of electrons towards fewer non-damaged PSI complexes could explain the hastened post-illumination re-reduction of P700+, aided by a slight increase in a stroma-sourced electron flux after prolonged pre-illumination at 4 degrees C. Quantifying the separate fluxes to P700+ helps to elucidate the effects of chilling of cucumber leaf discs in the light and the reasons for the hastened post-illumination re-reduction of P700+. PMID:18426807

  19. Defining lymphocyte-predominant breast cancer by the proportion of lymphocyte-rich stroma and its significance in routine histopathological diagnosis.

    PubMed

    Ohtani, Haruo; Mori-Shiraishi, Kazuko; Nakajima, Morio; Ueki, Hamaichi

    2015-12-01

    Lymphocyte-predominant breast cancer (LPBC) defined by the density of stromal lymphocytes shows favorable behavior. However, considerable distribution heterogeneity of lymphocytes is a major problem. The present study defined LPBC by the proportion of lymphocyte-rich stroma with the cut-off values of 30, 50, and 75%, and clinicopathologically analyzed mainly LPBC (area > 30%) defined by the cut-off value of 30%. LPBCs (area > 30%), 39 cases in total, were composed mainly of triple-negative and HER2(+) /ER(-) subtypes, without any luminal A-like subtype. LPBCs were composed predominantly of histological grade 3 tumors, without any grade 1 lesions. Multivariate analyses on 477 consecutive tumors revealed that ER-negativity and grade 3 status associated significantly with LPBC. LPBC (area > 30%) showed better disease-free survival than grade-matched controls, and it was a good indicator of complete pathological remission after pre-operative chemotherapy. Patients with LPBC with the cut-off value of 50% and that of 75% showed 100% disease-free survival. These results demonstrated the validity of our definition of LPBC. Our data also suggest that de-differentiated cancers without TILs could be regarded as high-grade cancer without lymphocyte-mediated responses. In conclusion, the definition of LPBC by the proportion of lymphoid stroma is useful for prognostication of high grade breast cancer in routine diagnosis. PMID:26530981

  20. Effect of surface fissure on apparent resistivity measurements

    NASA Astrophysics Data System (ADS)

    Sailhac, P.; Gance, J.; Malet, J.

    2013-12-01

    Fissures are features of interest, prone to create preferential flow path, modifying locally the soil hydrogeological behavior. Electrical Resistivity Tomography (ERT) is a suitable tool to monitor such preferential flow path. However, this technique is not efficient in the presence of surface fissure, due to a bad resistivity recovering around the fissure vicinity during the inversion process. Therefore, we propose a description of fissure effect on raw apparent resistivity on three resistivity arrays. The purposes of the study are multiple. First, we aim at making ERT users aware of surface fissure effect, and propose a first help to interpret basically resistivity pseudo sections. Second, we propose to ERT users to automatically conduct a surface fissure survey on the studied profile, in order to consider each fissure in a forward DC model and to suppress their effect. Finally, this study is only a first step toward 2D fissure shape inversion, and time-lapse monitoring of fissure drying and filling. In this study, we create a fissure model based on different geomorphological descriptors. After describing the FEM-DC forward modeling strategy, we investigate the fissure effect on pseudo section of apparent resistivity for a Wenner-Schlumberger (WS), a dipole-dipole (DD) and a gradient (GRAD) array. We determine a fissure detectability threshold for each array and perform a sensitivity analysis on the different fissure parameters (position, width, depth, dip angles...). The crack filling or drying effect is also investigated. The possibility to remove fissure effect and to propose a first interpretation of time-lapse data is illustrated on real data. This study show again the higher sensitivity of the DD array compared to the GRAD and WS arrays. Not only the maximal amplitude in the pseudo section is higher for the DD array, but also the anomaly pattern created by the fissure is much larger for this acquisition geometry. The minimal depth detectable for the DD

  1. Earthquake Apparent Stress Scaling for the 1999 Hector Mine Sequence

    NASA Astrophysics Data System (ADS)

    Walter, W. R.; Mayeda, K.

    2003-12-01

    There is currently a disagreement within the geophysical community on the way earthquake energy scales with magnitude. One set of studies finds evidence that energy release per seismic moment (apparent stress) is constant (e.g. Choy and Boatwright, 1995; McGarr, 1999; Ide and Beroza, 2001). Other studies find the apparent stress increases with magnitude (e.g. Kanamori et al., 1993; Abercrombie, 1995; Mayeda and Walter, 1996; Izutani and Kanamori, 2001). The resolution of this issue is complicated by the difficulty of accurately accounting for attenuation, radiation inhomogeneities, bandwidth and determining the seismic energy radiated by earthquakes over a wide range of event sizes in a consistent manner. We try to improve upon earlier results by using consistent techniques over common paths for a wide range of sizes and seismic phases. We have examined about 130 earthquakes from the Hector Mine earthquake sequence in Southern California. These earthquakes range in size from the October 16,1999 Mw=7.1 mainshock down to ML=3.0 aftershocks into 2000. The mainshock has unclipped Pg and Lg phases at a number of high quality regional stations (e.g. CMB, ELK, TUC) where we can use the common path to examine apparent stress scaling relations directly. We are careful to avoid any event selection bias that would be related to apparent stress values. We fix each stations path correction using the independent moment and energy estimates for the mainshock. We then use those corrections to determine the seismic energy for each event based on regional Lg spectra. We use a modeling technique (MDAC) based on a modified Brune (1970) spectral shape but without any assumptions of corner-frequency scaling (Walter and Taylor, 2002). We perform similar analysis using the Pg spectra. We find the energy estimates for the same events are consistent for Lg estimates, Pg estimates and the estimates using the independent regional coda envelope technique (Mayeda and Walter, 1996; Mayeda et al

  2. Deep-diving dinosaurs

    NASA Astrophysics Data System (ADS)

    Hayman, John

    2012-08-01

    Dysbaric bone necrosis demonstrated in ichthyosaurs may be the result of prolonged deep diving rather than rapid ascent to escape predators. The bone lesions show structural and anatomical similarity to those that may occur in human divers and in the deep diving sperm whale, Physeter macrocephalus.

  3. The Deep Space Network

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Deep Space Network progress in flight project support, tracking and data acquisition, research and technology, network engineering, hardware and software implementation, and operations is cited. Topics covered include: tracking and ground based navigation; spacecraft/ground communication; station control and operations technology; ground communications; and deep space stations.

  4. The deep space network

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The progress is reported of Deep Space Network (DSN) research in the following areas: (1) flight project support, (2) spacecraft/ground communications, (3) station control and operations technology, (4) network control and processing, and (5) deep space stations. A description of the DSN functions and facilities is included.

  5. Deep-diving dinosaurs.

    PubMed

    Hayman, John

    2012-08-01

    Dysbaric bone necrosis demonstrated in ichthyosaurs may be the result of prolonged deep diving rather than rapid ascent to escape predators. The bone lesions show structural and anatomical similarity to those that may occur in human divers and in the deep diving sperm whale, Physeter macrocephalus. PMID:22824942

  6. [Deep neck infections].

    PubMed

    Nowak, Katarzyna; Szyfter, Witold

    2006-01-01

    Deep neck infection is relatively rare but potentially life threatening complication of common oropharyngeal infections. This retrospective study was aimed at analyzing the occurrence of complications, diagnostic methods and proper management of deep neck infection. A review was conducted in 32 cases who were diagnosed as having deep neck infection from 1995 to 2005. The causes of deep neck infections were tonsillitis (16 cases), tooth diseases (6 cases), paratonsillar abscess (4 cases), parotitis (1 case), pussy lymphonodes after tonsillectomy (2 cases), pussy congenital neck cyst (1 case), chronic otitis media (1 case), parotitis (1 case), foreign body of the esophagus (1 case). All the puss bacterial cultivation were positive. All the patients were treated by different ways of chirurgical drainage and use of large dosage of antibiotics. Deep neck infection should be suspected in patients with long lasting fever and painful swelling of the neck and treatment should begin quick as possible. PMID:17152800

  7. Correlation Between the Clinical Parameters and Tissue Phenotype in Patients Affected by Deep-Infiltrating Endometriosis.

    PubMed

    Vinci, Giovanna; Arkwright, Sylviane; Audebourg, Anne; Radenen, Brigitte; Chapron, Charles; Borghese, Bruno; Dousset, Bertrand; Mehats, Celine; Vaiman, Daniel; Vacher-Lavenu, Marie-Cécile; Gogusev, Jean

    2016-09-01

    The current study aimed to identify and validate an applicable immunohistochemistry panel including Ki-67, c-MYC, estrogen receptor-α (ER-α), and progesterone receptor isoforms A/B (PR-A/B) in correlation with clinicopathological parameters in patients affected by deep infiltrating endometriosis. Tissue microarrays were prepared from a cohort of 113 patients. Phenotypic profile of the panel molecules was evaluated in glands and stroma in parallel with microvessels and stroma density measurements. Principal component analysis was performed on 8 immunohistochemical variables, 2 histological variables, and 8 subgroups of clinical parameters. The immunohistochemical profiling showed consistent Ki-67 immunostaining in 17.9% of the samples and c-MYC in 83.1%, while intense ER-α immunoreactivity was detected in 84% of the samples and PR-A/B isoforms in 24.1% of them. The combination of clinical parameters and tissue phenotype allowed a stratification of endometriosis-affected patients. Such novel phenotypical and clinical correlation could be helpful in the future studies for a better stratification of the disease aiming at a personalized patient care. PMID:26994067

  8. Apparent chlorofluorocarbon age of ground water of the shallow aquifer system, Naval Weapons Station Yorktown, Yorktown, Virginia

    USGS Publications Warehouse

    Nelms, David L.; Harlow,, George E., Jr.; Brockman, Allen R.

    2001-01-01

    reporting limit of 0.3 to 15.9 tritium units (TU) with a median value of 10.8 TU. Water-quality field properties are highly variable for ground water with apparent CFC ages less than 15 years because of geochemical processes within local flow systems. Ground water with apparent CFC ages greater than 15 years represents more stable conditions in subregional flow systems. The range of apparent CFC ages is slightly greater than the ranges in time of travel of ground water calculated for shallow wells (less than 60- feet deep) from flow-path analysis. Calculated travel times to springs can be up to two orders of magnitude greater than the CFC-based apparent ages. Reasonable assumptions of values for hydraulic parameters can result in substantial overestimates for time of travel to springs. Recharge rates computed from apparent CFC ages range from 0.29 to 0.89 feet per year (ft/ yr) with an average value of 0.54 ft/yr. The analysis of apparent CFC ages in conjunction with geohydrologic data indicates that young water (less than 50 years) is present at depth (nearly 120 feet) and that both local and subregional flow systems occur in the shallow aquifer system at the Station. The addition of the dimension of time to the three-dimensional framework of Brockman and others (1997) will benefit current (2001) and future remediation activities by providing estimates of advective transport rates and how these rates vary depending upon geohydrologic setting and position within the ground-water-flow system. Estimated ground-water apparent ages and recharge rates can be used as calibration criteria in simulations of ground-water flow on the Station to refine and constrain future ground-water-flow models of the shallow aquifer system.

  9. Identifying apparent velocity changes in cross correlated microseism noise data

    NASA Astrophysics Data System (ADS)

    Friderike Volk, Meike; Bean, Christopher; Lokmer, Ivan; Pérez, Nemesio; Ibáñez, Jesús

    2015-04-01

    Currently there is a strong interest of using cross correlation of ambient noise to retrieve Green's functions. These are usually used to calculate the seismic wave velocity of the subsurface and therefore can be used for subsurface imaging or monitoring of various geological settings where we expect rapid velocity changes (e.g. reservoirs or volcanoes). The assumption of this method is that the wavefields which are correlated must be diffuse. This criterion is fulfilled if the ambient noise sources are uniformly distributed or the scattering in the medium is high enough to mitigate any source directivity. The location of the sources is usually unknown and it can change in time. These temporal and spatial variations of the microseism noise sources may lead to changes in the retrieved Green's functions, and so, to the apparent changes in seismic wave velocities. To further investigate the apparent changes in Green's functions we undertook an active seismic experiment in Tenerife lasting three months. A small airgun was used as an active source and was shooting repeatedly every 15 minutes. The shots and the microseism noise were recorded at several seismic stations at the same time. That data set gives us the opportunity to compare the changes in seismic wave velocity recovered through cross correlation of ambient noise and changes we measure through active shots from the airgun. The aim is to distinguish between apparent seismic velocity changes and seismic velocity changes caused by changes in the medium. We also use the data set to track the direction of the microseism noise sources to see if changes which are only recovered through cross correlation can be related to temporal and spatial variations of the microseism noise sources.

  10. Ultrasonic backscatter from cancellous bone: the apparent backscatter transfer function.

    PubMed

    Hoffmeister, Brent K; Mcpherson, Joseph A; Smathers, Morgan R; Spinolo, P Luke; Sellers, Mark E

    2015-12-01

    Ultrasonic backscatter techniques are being developed to detect changes in cancellous bone caused by osteoporosis. Many techniques are based on measurements of the apparent backscatter transfer function (ABTF), which represents the backscattered power from bone corrected for the frequency response of the measurement system. The ABTF is determined from a portion of the backscatter signal selected by an analysis gate of width τw delayed by an amount τd from the start of the signal. The goal of this study was to characterize the ABTF for a wide range of gate delays (1 μs ≤ τd ≤ 6 μs) and gate widths (1 μs ≤ τw ≤ 6 μs). Measurements were performed on 29 specimens of human cancellous bone in the frequency range 1.5 to 6.0 MHz using a broadband 5-MHz transducer. The ABTF was found to be an approximately linear function of frequency for most choices of τd and τw. Changes in τd and τw caused the frequency-averaged ABTF [quantified by apparent integrated backscatter (AIB)] and the frequency dependence of the ABTF [quantified by frequency slope of apparent backscatter (FSAB)] to change by as much as 24.6 dB and 6.7 dB/MHz, respectively. τd strongly influenced the measured values of AIB and FSAB and the correlation of AIB with bone density (-0.95 ≤ R ≤ +0.68). The correlation of FSAB with bone density was influenced less strongly by τd (-0.97 ≤ R ≤ -0.87). τw had a weaker influence than τd on the measured values of AIB and FSAB and the correlation of these parameters with bone density. PMID:26683412

  11. Mechanical Components from Highly Recoverable, Low Apparent Modulus Materials

    NASA Technical Reports Server (NTRS)

    Padula, Santo, II (Inventor); Noebe, Ronald D. (Inventor); Stanford, Malcolm K. (Inventor); DellaCorte, Christopher (Inventor)

    2015-01-01

    A material for use as a mechanical component is formed of a superelastic intermetallic material having a low apparent modulus and a high hardness. The superelastic intermetallic material is conditioned to be dimensionally stable, devoid of any shape memory effect and have a stable superelastic response without irrecoverable deformation while exhibiting strains of at least 3%. The method of conditioning the superelastic intermetallic material is described. Another embodiment relates to lightweight materials known as ordered intermetallics that perform well in sliding wear applications using conventional liquid lubricants and are therefore suitable for resilient, high performance mechanical components such as gears and bearings.

  12. Atrial Septal Aneurysm Presenting as Clubbing without Clinically Apparent Cyanosis.

    PubMed

    Goyal, Laxmi Kant; Banerjee, S; Yadav, R N; Singh, Gajraj; Ganguli, Sujata; Isran, Rohit

    2015-09-01

    Atrial septal aneurysm (ASA) is a localised "saccular" deformity which protrudes to the right or the left atrium or on both sides. It is a rare, but well recognised cardiac abnormality. It is usually an incidental finding or may presents as atrial arrhythmias or arterial embolism. Though it is an acyanotic congenital heart disease but it may result in significant right to left shunt and cyanosis. We describe a patient of ASA with atrial septal defect who presented with clubbing and right to left shunt without clinically apparent cyanosis. PMID:27608873

  13. Downscaling Smooth Tomographic Models: Separating Intrinsic and Apparent Anisotropy

    NASA Astrophysics Data System (ADS)

    Bodin, Thomas; Capdeville, Yann; Romanowicz, Barbara

    2016-04-01

    In recent years, a number of tomographic models based on full waveform inversion have been published. Due to computational constraints, the fitted waveforms are low pass filtered, which results in an inability to map features smaller than half the shortest wavelength. However, these tomographic images are not a simple spatial average of the true model, but rather an effective, apparent, or equivalent model that provides a similar 'long-wave' data fit. For example, it can be shown that a series of horizontal isotropic layers will be seen by a 'long wave' as a smooth anisotropic medium. In this way, the observed anisotropy in tomographic models is a combination of intrinsic anisotropy produced by lattice-preferred orientation (LPO) of minerals, and apparent anisotropy resulting from the incapacity of mapping discontinuities. Interpretations of observed anisotropy (e.g. in terms of mantle flow) requires therefore the separation of its intrinsic and apparent components. The "up-scaling" relations that link elastic properties of a rapidly varying medium to elastic properties of the effective medium as seen by long waves are strongly non-linear and their inverse highly non-unique. That is, a smooth homogenized effective model is equivalent to a large number of models with discontinuities. In the 1D case, Capdeville et al (GJI, 2013) recently showed that a tomographic model which results from the inversion of low pass filtered waveforms is an homogenized model, i.e. the same as the model computed by upscaling the true model. Here we propose a stochastic method to sample the ensemble of layered models equivalent to a given tomographic profile. We use a transdimensional formulation where the number of layers is variable. Furthermore, each layer may be either isotropic (1 parameter) or intrinsically anisotropic (2 parameters). The parsimonious character of the Bayesian inversion gives preference to models with the least number of parameters (i.e. least number of layers, and

  14. Apparent diffusion coefficient map of a case of extramedullary plasmacytoma

    PubMed Central

    Ramachandran, Amrutha; Inyang, Alero F; Subhawong, Ty K

    2016-01-01

    Plasmacytomas are rare tumors, which arise from the monoclonal proliferation of malignant plasma cells. They may affect either the bony skeleton or rarely the soft tissues, the latter being referred to as extramedullary or extraosseous. We report a case of an extramedullary plasmacytoma that presented as a soft tissue mass involving the muscles of the left leg, in a patient who was previously treated for multiple myeloma. We describe the MR Imaging characteristics of the tumor and highlight the usefulness of diffusion-weighted imaging with apparent diffusion coefficient mapping. PMID:27200157

  15. Study on Apparent Viscosity and Structure of Foaming Slag

    NASA Astrophysics Data System (ADS)

    Martinsson, Johan; Glaser, Björn; Sichen, Du

    2016-07-01

    Foaming slag was generated using induction heating. The foam was found non-Newtonian having much higher apparent viscosity compared to the dynamic viscosity of pure slag. Quenched foam was examined. The appearance of the foaming slag was very different from silicone oil-gas foam. The size of gas bubbles ranged from 0.1 to 4 mm (while in the case of silicone oil, 1 to 2 mm). The gas fraction in the foam was considerably lower than in the case of silicone oil.

  16. Deep Moonquakes: Remaining Problems

    NASA Technical Reports Server (NTRS)

    Nakamura, Y.

    2004-01-01

    We have recently reexamined more than 9000 United States previously unidentified seismic events catalogued during the Apollo landing missions and positively identified for the first time about 30 deep moonquake nests on the far side of the Moon. Although only a few of them are currently locatable, the relative arrival times among stations for the rest and presence or absence of seismic signals at particular stations suggest that either (a) the region within about $40\\deg$ of the antipode is aseismic or (b) the deep interior of the Moon severely attenuates or deflects seismic waves. Aside from the obvious question of how to distinguish between such hypothetical models, this effort raised several more general questions concerning the use of deep moonquake signals to infer the structure and dynamics of the deep interior of the Moon. Among more important ones are: (1) How reliable are the seismic arrival picks from which to compute the seismic velocity variations in the Moon? (2) How do the possible lateral variations in seismic velocity affect the computed radial variation in seismic velocity at depth? (3) Can we tell more about the distribution and mechanism of deep moonquakes from the newly expanded database of identified deep moonquakes? Questions (1) and (2) are especially important because the inferred deep internal structure of the Moon depends critically on their answers. Answering these questions may demand additional data collected on future lunar missions, but some may be resolved with further examination of the existing data.

  17. Deep subsurface microbial processes

    USGS Publications Warehouse

    Lovley, D.R.; Chapelle, F.H.

    1995-01-01

    Information on the microbiology of the deep subsurface is necessary in order to understand the factors controlling the rate and extent of the microbially catalyzed redox reactions that influence the geophysical properties of these environments. Furthermore, there is an increasing threat that deep aquifers, an important drinking water resource, may be contaminated by man's activities, and there is a need to predict the extent to which microbial activity may remediate such contamination. Metabolically active microorganisms can be recovered from a diversity of deep subsurface environments. The available evidence suggests that these microorganisms are responsible for catalyzing the oxidation of organic matter coupled to a variety of electron acceptors just as microorganisms do in surface sediments, but at much slower rates. The technical difficulties in aseptically sampling deep subsurface sediments and the fact that microbial processes in laboratory incubations of deep subsurface material often do not mimic in situ processes frequently necessitate that microbial activity in the deep subsurface be inferred through nonmicrobiological analyses of ground water. These approaches include measurements of dissolved H2, which can predict the predominant microbially catalyzed redox reactions in aquifers, as well as geochemical and groundwater flow modeling, which can be used to estimate the rates of microbial processes. Microorganisms recovered from the deep subsurface have the potential to affect the fate of toxic organics and inorganic contaminants in groundwater. Microbial activity also greatly influences 1 the chemistry of many pristine groundwaters and contributes to such phenomena as porosity development in carbonate aquifers, accumulation of undesirably high concentrations of dissolved iron, and production of methane and hydrogen sulfide. Although the last decade has seen a dramatic increase in interest in deep subsurface microbiology, in comparison with the study of

  18. Deep divergence and apparent sex-biased dispersal revealed by a Y-linked marker in rainbow trout

    PubMed Central

    Brunelli, Joseph P.; Steele, Craig A.; Thorgaard, Gary H.

    2010-01-01

    Y-chromosome and mitochondrial DNA markers can reveal phylogenetic patterns by allowing tracking of male and female lineages, respectively. We used sequence data from a recently discovered Y-linked marker and a mitochondrial marker to examine phylogeographic structure in the widespread and economically important rainbow trout (Oncorhynchus mykiss). Two distinct geographic groupings that generally correspond to coastal and inland subspecies were evident within the Y marker network while the mtDNA haplotype network showed little geographic structure. Our results suggest that male-specific behavior has prevented widespread admixture of Y haplotypes and that gene flow between the coastal and inland subspecies has largely occurred through females. This new Y marker may also aid conservation efforts by genetically identifying inland populations that have not hybridized with widely stocked coastal-derived hatchery fish. PMID:20546904

  19. Deep venous reconstructive surgery.

    PubMed

    Maleti, Oscar; Lugli, Marzia; Tripathi, Ramesh K

    2015-03-01

    Surgical correction of deep venous reflux is a valuable adjunct in treatment of selected patient with lower limb venous ulcer. Deep venous obstruction and superficial reflux is must be corrected first. Sustained venous ulcer healing and reduced ambulatory venous hypertension can be achieved in patients with both primary and secondary deep venous insufficiency. When direct valve repair is possible, valvuloplasty is the best option, but when this is not feasible, other techniques can be used, including femoral vein transposition into the great saphenous vein, vein valve transplant, neovalve construction, or nonautologous artificial venous valve. PMID:26358308

  20. Low apparent aldose reductase activity produced by monosaccharide autoxidation.

    PubMed Central

    Wolff, S P; Crabbe, M J

    1985-01-01

    Low apparent aldose reductase activity, as measured by NADPH oxidation, can be produced by the spontaneous autoxidation of monosaccharides. NADPH is oxidized to metabolically active NADP+ in a solution of autoxidizing DL-glyceraldehyde at rates of up to 15 X 10(-4) A340/min. The close parallelism between the effects of buffer salt type and concentration, monosaccharide structure and temperature activation on autoxidation and NADPH oxidation imply that autoxidation is a prerequisite for the NADPH oxidation, probably via the hydroperoxy radical. Nucleotide-binding proteins enhanced NADPH oxidation induced by DL-glyceraldehyde, up to 10.6-fold with glucose-6-phosphate dehydrogenase. Glutathione reductase-catalysed NADPH oxidation in the presence of autoxidizing monosaccharide showed many characteristics of the aldose reductase reaction. Aldose reductase inhibitors acted as antioxidants in inhibiting this NADPH oxidation. These results indicate that low apparent aldose reductase activities may be due to artifacts of monosaccharide autoxidation, and could provide an explanation for the non-linear steady-state kinetics observed with DL-glyceraldehyde and aldose reductase. PMID:2985042

  1. Apparent Versus True Carrier Multiplication Yields in Semiconductor Nanocrystals

    SciTech Connect

    McGuire, John A.; Sykora, Milan; Joo, Jin; Pietryga, Jeffrey M.; Klimov, Victor I.

    2010-05-11

    Generation of multiple electron-hole pairs (excitons) by single photons, known as carrier multiplication (CM), has the potential to appreciably improve the performance of solar photovoltaics. In semiconductor nanocrystals, this effect usually has been detected using a distinct dynamical signature of multiexcitons associated with their fast Auger recombination. Here, we show that uncontrolled photocharging of the nanocrystal core can lead to exaggeration of the Auger decay component and, as a result, significant deviations of the apparent CM efficiencies from their true values. Specifically, we observe that for the same sample, apparent multiexciton yields can differ by a factor of ~3 depending on whether the nanocrystal solution is static or stirred. We show that this discrepancy is consistent with photoinduced charging of the nanocrystals in static solutions, the effect of which is minimized in the stirred case where the charged nanocrystals are swept from the excitation volume between sequential excitation pulses. Using side-by-side measurements of CM efficiencies and nanocrystal charging, we show that the CM results obtained under static conditions converge to the values measured for stirred solutions after we accurately account for the effects of photocharging. This study helps to clarify the recent controversy over CM in nanocrystals and highlights some of the issues that must be carefully considered in spectroscopic studies of this process.

  2. No Apparent Polar Wander of Tarim Since the Carboniferous?

    NASA Astrophysics Data System (ADS)

    Gilder, S.; Chen, Y.; Gomez, J.; Courtillot, V.; Cogne, J.

    2005-12-01

    We report new Permian and Lower to Middle Jurassic paleomagnetic results from the Tarim Block. The Permian red beds pass the fold test, and all samples have reverse polarities, consistent with acquisition of magnetic remanence during the Kiaman Reversed Polarity Superchron. Lower to Middle Jurassic marly limestones also possess a magnetic component characterized by solely reverse polarities and a positive fold test. However, the solely reversed polarities pose a problem because the Lower to Middle Jurassic is thought to have one of the highest reversal frequencies in Earth`s history. Rock magnetic experiments argue for an early-diagenetic age for the magnetization. Together, these new results add to the plethora of paleomagnetic data for Tarim, which is represented by a quasi-continuous time sequence of paleomagnetic poles since the Permo-Carboniferous. After accounting for local vertical axis block rotations and inclination shallowing effects, we find that Tarim has experienced virtually no apparent polar wander since the Carboniferous. Tarim`s apparent polar wander path (APWP) is significantly different than the Eurasian APWP, and a comparison of the two imposes geologically unrealistic tectonic displacements. This leads to the Tarim APWP paradox: are most of the Tarim rocks overprinted, or is the Eurasian APWP not representative of the land east of the Ural Mountains? If the latter is true, then previous tectonic reconstructions must be reconsidered. If the former is true, then when/how can we rely on the paleomagnetic data?

  3. On the thermodynamics of the cosmological apparent horizon

    NASA Astrophysics Data System (ADS)

    Pollock, M. D.

    2015-11-01

    It has been shown by Cai et al. that the apparent horizon of radius r0 in the cosmological Friedmann space-time emits radiation at the temperature T0 = 1/2π r0. Here, we derive this result from the Wheeler-DeWitt equation for the wave function of the Universe Ψ, starting from a classical gravitational Lagrangian L that contains a quadratic higher-derivative term R2 , the scalar component of which is non-tachyonic, by application of the horizon hypothesis and definition of the physical three-space on the time-slice dx0 = 0. We also extend our previous analysis of the Wheeler-DeWitt equation for the wave function Φ of the apparent horizon of the de Sitter space-time to include the case of a more general energy-momentum source, that generates an arbitrary Friedmann space-time, confirming the expression for T0 after application of the ADM formalism.

  4. Pore fluid pressure, apparent friction, and Coulomb failure

    USGS Publications Warehouse

    Beeler, N.M.; Simpson, R.W.; Hickman, S.H.; Lockner, D.A.

    2000-01-01

    Many recent studies of stress-triggered seismicity rely on a fault failure model with a single free parameter, the apparent coefficient of friction, presumed to be a material constant with possible values 0 ≤ μ′ ≤ 1. These studies may present a misleading view of fault strength and the role of pore fluid pressure in earthquake failure. The parameter μ′ is intended to incorporate the effects of both friction and pore pressure, but is a material constant only if changes in pore fluid pressure induced by changes in stress are proportional to the normal stress change across the potential failure plane. Although specific models of fault zones permit such a relation, neither is it known that fault zones within the Earth behave this way, nor is this behavior expected in all cases. In contrast, for an isotropic homogeneous poroelastic model the pore pressure changes are proportional to changes in mean stress, μ′ is not a material constant, and −∞ ≤ μ′ ≤ +∞. Analysis of the change in Coulomb failure stress for tectonically loaded reverse and strike-slip faults shows considerable differences between these two pore pressure models, suggesting that such models might be distinguished from one another using observations of triggered seismicity (e.g., aftershocks). We conclude that using the constant apparent friction model exclusively in studies of Coulomb failure stress is unwise and could lead to significant errors in estimated stress change and seismic hazard.

  5. The deep space network

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The functions and facilities of the Deep Space Network are considered. Progress in flight project support, tracking and data acquisition research and technology, network engineering, hardware and software implementation, and operations is reported.

  6. The Deep Space Network

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Progress on the Deep Space Network (DSN) supporting research and technology, advanced development, engineering and implementation, and DSN operations is presented. The functions and facilities of the DSN are described.

  7. The Deep Space Network

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The various systems and subsystems are discussed for the Deep Space Network (DSN). A description of the DSN is presented along with mission support, program planning, facility engineering, implementation and operations.

  8. Nurturing Deep Connections.

    ERIC Educational Resources Information Center

    Kessler, Rachael

    2002-01-01

    Argues that the missing ingredient in school reform is soul, that is, deep connections among students, teachers, and administrators. Discusses five principles of leadership with soul: Personalize, pacing, permission, protection, and paradox. (PKP)

  9. The deep space network

    NASA Technical Reports Server (NTRS)

    1979-01-01

    A report is given of the Deep Space Networks progress in (1) flight project support, (2) tracking and data acquisition research and technology, (3) network engineering, (4) hardware and software implementation, and (5) operations.

  10. The deep space network

    NASA Technical Reports Server (NTRS)

    1977-01-01

    A Deep Space Network progress report is presented dealing with in flight project support, tracking and data acquisition research and technology, network engineering, hardware and software implementation, and operations.

  11. The deep space network

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Progress is reported in flight project support, tracking and data acquisition research and technology, network engineering, hardware and software implementation, and operations. The functions and facilities of the Deep Space Network are emphasized.

  12. The deep space network

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The facilities, programming system, and monitor and control system for the deep space network are described. Ongoing planetary and interplanetary flight projects are reviewed, along with tracking and ground-based navigation, communications, and network and facility engineering.

  13. Reading Knee-Deep

    ERIC Educational Resources Information Center

    Jewett, Pamela

    2007-01-01

    Freire told his audience at a seminar at the University of Massachusetts, "You need to read knee-deep in texts, for deeper than surface meanings, and you need to know the words to be able to do it" (quoted in Cleary, 2003). In a children's literature class, fifteen teachers and I traveled along a path that moved us toward reading knee-deep as we…

  14. Exploration for deep coal

    SciTech Connect

    2008-12-15

    The most important factor in safe mining is the quality of the roof. The article explains how the Rosebud Mining Co. conducts drilling and exploration in 11 deep coal mine throughout Pennsylvania and Ohio. Rosebud uses two Atlas Copco CS10 core drilling rigs mounted on 4-wheel drive trucks. The article first appeared in Atlas Copco's in-house magazine, Deep Hole Driller. 3 photos.

  15. The deep space network

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The objectives, functions, and organization of the Deep Space Network are summarized along with deep space station, ground communication, and network operations control capabilities. Mission support of ongoing planetary/interplanetary flight projects is discussed with emphasis on Viking orbiter radio frequency compatibility tests, the Pioneer Venus orbiter mission, and Helios-1 mission status and operations. Progress is also reported in tracking and data acquisition research and technology, network engineering, hardware and software implementation, and operations.

  16. The Deep Space Network

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The objectives, functions, and organization, of the Deep Space Network are summarized. Deep Space stations, ground communications, and network operations control capabilities are described. The network is designed for two-way communications with unmanned spacecraft traveling approximately 1600 km from earth to the farthest planets in the solar system. It has provided tracking and data acquisition support for the following projects: Ranger, Surveyor, Mariner, Pioneer, Apollo, Helios, Viking, and the Lunar Orbiter.

  17. Electrochemistry in deep eutectic solvents.

    PubMed

    Nkuku, Chiemela A; LeSuer, Robert J

    2007-11-22

    We report the cyclic voltammetry, chronoamperometry, and scanning electrochemical microscopy of ferrocene dissolved in deep eutectic solvents (DES), consisting of choline chloride (ChCl) and either trifluoroacetamide (TFA) or malonic acid as the hydrogen-bond donor. Despite the use of ultramicroelectrodes, which were required due to the modest conductivities of the DES employed, linear diffusion behavior was observed in cyclic voltammetric experiments. The high viscosity of 1:2 ChCl/TFA relative to non-aqueous electrochemical solvents leads to a low diffusion coefficient, 2.7 x 10(-8) cm2 s(-1) for ferrocene in this medium. Because of the difficulties in achieving steady-state conditions, SECM approach curves were tip velocity dependent. Under certain conditions, SECM approach curves to an insulating substrate displayed a positive-feedback response. Satisfactory simulation of this unexpected behavior was obtained by including convection terms into the mass transport equations typically used for SECM theory. The observance of positive-feedback behavior at an insulating substrate can be described in terms of a dimensionless parameter, the Peclet number, which is the ratio of the convective and diffusive timescales. Fitting insulator approach curves of ferrocene in 1:2 ChCl/TFA shows an apparent increase in the diffusion coefficient with increasing tip velocity, which can be explained by DES behaving as a shear thinning non-Newtonian fluid. PMID:17973421

  18. Stroma-induced Jagged1 expression drives PC3 prostate cancer cell migration; disparate effects of RIP-generated proteolytic fragments on cell behaviour and Notch signaling.

    PubMed

    Delury, Craig; Hart, Claire; Brown, Mick; Clarke, Noel; Parkin, Edward

    2016-03-25

    The Notch ligand Jagged1 is subject to regulated intramembrane proteolysis (RIP) which yields a soluble ectodomain (sJag) and a soluble Jagged1 intracellular domain (JICD). The full-length Jagged1 protein enhances prostate cancer (PCa) cell proliferation and is highly expressed in metastatic cells. However, little is known regarding the mechanisms by which Jagged1 or its RIP-generated fragments might promote PCa bone metastasis. In the current study we show that bone marrow stroma (BMS) induces Jagged1 expression in bone metastatic prostate cancer PC3 cells and that this enhanced expression is mechanistically linked to the promotion of cell migration. We also show that RIP-generated Jagged1 fragments exert disparate effects on PC3 cell behaviour and Notch signaling. In conclusion, the expression of both the full-length ligand and its RIP-generated fragments must be considered in tandem when attempting to regulate Jagged1 as a possible PCa therapy. PMID:26921446

  19. An Apparent Paradox in Verification of Rainfall Estimates.

    NASA Astrophysics Data System (ADS)

    Ciach, G. J.

    2009-05-01

    A problem that is a source of permanent cognitive confusion in comprehensive evaluations of different rainfall estimates is presented. The problem stems from the existence of two conditional biases (CB) inherent to the uncertainties of the estimates. The two CBs, called "CB type 1" and "CB type 2," are recognized by researchers familiar with the distribution-oriented framework for complete verification of hydrological and meteorological products. Although the mathematical definitions of the two CBs are clear, a reality check reveals that their meaningful interpretation is problematic. It can even result in self-contradictory conclusions suggesting both systematic overestimation and underestimation of strong rainfall by the same rainfall estimation products. A solution to this apparent paradox is discussed. This investigation is based on large data samples of different radar rainfall estimates and the corresponding highly accurate ground reference. Understanding the two CBs, their physical consequences and the fundamental inter-relations between them is essential for informed usage of these uncertainty characteristics.

  20. Species-barrier-independent prion replication in apparently resistant species

    NASA Astrophysics Data System (ADS)

    Hill, Andrew F.; Joiner, Susan; Linehan, Jackie; Desbruslais, Melanie; Lantos, Peter L.; Collinge, John

    2000-08-01

    Transmission of prions between mammalian species is thought to be limited by a "species barrier," which depends on differences in the primary structure of prion proteins in the infecting inoculum and the host. Here we demonstrate that a strain of hamster prions thought to be nonpathogenic for conventional mice leads to prion replication to high levels in such mice but without causing clinical disease. Prions pathogenic in both mice and hamsters are produced. These results demonstrate the existence of subclinical forms of prion infection with important public health implications, both with respect to iatrogenic transmission from apparently healthy humans and dietary exposure to cattle and other species exposed to bovine spongiform encephalopathy prions. Current definitions of the species barrier, which have been based on clinical end-points, need to be fundamentally reassessed.

  1. Random variability explains apparent global clustering of large earthquakes

    USGS Publications Warehouse

    Michael, A.J.

    2011-01-01

    The occurrence of 5 Mw ≥ 8.5 earthquakes since 2004 has created a debate over whether or not we are in a global cluster of large earthquakes, temporarily raising risks above long-term levels. I use three classes of statistical tests to determine if the record of M ≥ 7 earthquakes since 1900 can reject a null hypothesis of independent random events with a constant rate plus localized aftershock sequences. The data cannot reject this null hypothesis. Thus, the temporal distribution of large global earthquakes is well-described by a random process, plus localized aftershocks, and apparent clustering is due to random variability. Therefore the risk of future events has not increased, except within ongoing aftershock sequences, and should be estimated from the longest possible record of events.

  2. Thermodynamics of Evolving Lorentzian Wormhole at Apparent and Event Horizons

    NASA Astrophysics Data System (ADS)

    Debnath, Ujjal; Jamil, Mubasher; Myrzakulov, Ratbay; Akbar, M.

    2014-12-01

    We have investigated the non-static Lorentzian Wormhole model in presence of anisotropic pressure. We have presented some exact solutions of Einstein equations for anisotropic pressure case. Introducing two EoS parameters we have shown that these solutions give very rich dynamics of the universe yielding to the different expansion history of it in the r - direction and in the T - direction. The corresponding explicit forms of the shape function b( r) is presented.We have shown that the Einstein's field equations and unified first law are equivalent for the dynamical wormhole model. The first law of thermodynamics has been derived by using the Unified first law. The physical quantities including surface gravity and the temperature are derived for the wormhole. Here we have obtained all the results without any choice of the shape function. The validity of generalized second law (GSL) of thermodynamics has been examined at apparent and event horizons for the evolving Lorentzian wormhole.

  3. Solving the apparent diversity-accuracy dilemma of recommender systems

    PubMed Central

    Zhou, Tao; Kuscsik, Zoltán; Liu, Jian-Guo; Medo, Matúš; Wakeling, Joseph Rushton; Zhang, Yi-Cheng

    2010-01-01

    Recommender systems use data on past user preferences to predict possible future likes and interests. A key challenge is that while the most useful individual recommendations are to be found among diverse niche objects, the most reliably accurate results are obtained by methods that recommend objects based on user or object similarity. In this paper we introduce a new algorithm specifically to address the challenge of diversity and show how it can be used to resolve this apparent dilemma when combined in an elegant hybrid with an accuracy-focused algorithm. By tuning the hybrid appropriately we are able to obtain, without relying on any semantic or context-specific information, simultaneous gains in both accuracy and diversity of recommendations. PMID:20176968

  4. Apparent viscosity during unyielding of a thixotropic yield stress fluid

    NASA Astrophysics Data System (ADS)

    Renardy, Yuriko; Maki, Kara

    2012-11-01

    We present a mathematical interpretation of a thixotropic yield stress fluid, based on a viscoelastic constitutive law in the limit of large relaxation time, together with a Newtonian solvent. The dynamics is initiated by a step-up or step-down in prescribed shear stress. There is no presumption of a yield stress, but nevertheless, we obtain yield stress behavior. The thixotropic behavior of the model arises from the multiple time scales which emerge in the limit of large relaxation time. These give rise to fast dynamics (elastic deformation) and slow dynamics (unyielding), in addition to yielded dynamics for shear flow. We present how the model predicts the evolution of apparent viscosity during unyielding. Supported by NSF-DMS, AWM.

  5. Solving the apparent diversity-accuracy dilemma of recommender systems.

    PubMed

    Zhou, Tao; Kuscsik, Zoltán; Liu, Jian-Guo; Medo, Matús; Wakeling, Joseph Rushton; Zhang, Yi-Cheng

    2010-03-01

    Recommender systems use data on past user preferences to predict possible future likes and interests. A key challenge is that while the most useful individual recommendations are to be found among diverse niche objects, the most reliably accurate results are obtained by methods that recommend objects based on user or object similarity. In this paper we introduce a new algorithm specifically to address the challenge of diversity and show how it can be used to resolve this apparent dilemma when combined in an elegant hybrid with an accuracy-focused algorithm. By tuning the hybrid appropriately we are able to obtain, without relying on any semantic or context-specific information, simultaneous gains in both accuracy and diversity of recommendations. PMID:20176968

  6. 3, 3', 5-triiodo-L-thyronine Increases In Vitro Chondrogenesis of Mesenchymal Stem Cells From Human Umbilical Cord Stroma Through SRC2.

    PubMed

    Fernández-Pernas, Pablo; Fafián-Labora, Juan; Lesende-Rodriguez, Iván; Mateos, Jesús; De la Fuente, Alexandre; Fuentes, Isaac; De Toro Santos, Javier; Blanco García, Fco; Arufe, María C

    2016-09-01

    Our group focuses on the study of mesenchymal stem cells (MSCs) from human umbilical cord stroma or Warthońs jelly and their directed differentiation toward chondrocyte-like cells capable of regenerating damaged cartilage when transplanted into an injured joint. This study aimed to determine whether lactogenic hormone prolactin (PRL) or 3, 3', 5-triiodo-L-thyronine (T3), the active thyroid hormone, modulates chondrogenesis in our in vitro model of directed chondrogenic differentiation, and whether Wnt signalling is involved in this modulation. MSCs from human umbilical cord stroma underwent directed differentiation toward chondrocyte-like cells by spheroid formation. The addition of T3 to the chondrogenic medium increased the expression of genes linked to chondrogenesis like collagen type 2, integrin alpha 10 beta 1, and Sox9 measured by quantitative real time polymerase chain reaction (qRT-PCR) analysis. Levels of collagen type 2 and aggrecane analyzed by immunohistochemistry, and staining by Safranin O were increased after 14 days in spheroid culture with T3 compared to those without T3 or only with PRL. B-catenin, Frizzled, and GSK-3β gene expressions were significantly higher in spheroids cultured with chondrogenic medium (CM) plus T3 compared to CM alone after 14 days in culture. The increase of chondrogenic differentiation was inhibited when the cells were treated with T3 plus ML151, an inhibitor of the T3 steroid receptor. This work demonstrates, for first time, that T3 promotes differentiation towards chondrocytes-like cells in our in vitro model, that this differentiation is mediated by steroid receptor co-activator 2 (SRC2) and does not induce hypertrophy. J. Cell. Biochem. 117: 2097-2108, 2016. © 2016 Wiley Periodicals, Inc. PMID:26869487

  7. Understanding of the Viscoelastic Response of the Human Corneal Stroma Induced by Riboflavin/UV-A Cross-Linking at the Nano Level

    PubMed Central

    Labate, Cristina; De Santo, Maria Penelope; Lombardo, Giuseppe; Lombardo, Marco

    2015-01-01

    Purpose To investigate the viscoelastic changes of the human cornea induced by riboflavin/UV-A cross-linking using Atomic Force Microscopy (AFM) at the nano level. Methods Seven eye bank donor corneas were investigated, after gently removing the epithelium, using a commercial AFM in the force spectroscopy mode. Silicon cantilevers with tip radius of 10 nm and spring elastic constants between 26- and 86-N/m were used to probe the viscoelastic properties of the anterior stroma up to 3 µm indentation depth. Five specimens were tested before and after riboflavin/UV-A cross-linking; the other two specimens were chemically cross-linked using glutaraldehyde 2.5% solution and used as controls. The Young’s modulus (E) and the hysteresis (H) of the corneal stroma were quantified as a function of the application load and scan rate. Results The Young’s modulus increased by a mean of 1.1-1.5 times after riboflavin/UV-A cross-linking (P<0.05). A higher increase of E, by a mean of 1.5-2.6 times, was found in chemically cross-linked specimens using glutaraldehyde 2.5% (P<0.05). The hysteresis decreased, by a mean of 0.9-1.5 times, in all specimens after riboflavin/UV-A cross-linking (P<0.05). A substantial decrease of H, ranging between 2.6 and 3.5 times with respect to baseline values, was observed in glutaraldehyde-treated corneas (P<0.05). Conclusions The present study provides the first evidence that riboflavin/UV-A cross-linking induces changes of the viscoelastic properties of the cornea at the scale of stromal molecular interactions. PMID:25830534

  8. Evaluation of T, B and natural killer lymphocyte in the cervical stroma of HIV-positive and negative patients with cervical intraepithelial neoplasia.

    PubMed

    Lucena, Adriana A S; Guimarães, Mírian Viviane M B; Michelin, Márcia A; Lodi, Cláudia T C; Lima, Maria Inês M; Murta, Eddie Fernando Candido; Melo, Victor Hugo

    2016-01-01

    Cervical intraepithelial neoplasias (CIN) are closely associated with oncogenic subtypes of the human papillomavirus (HPV). In the presence of this virus, it is known that the activation or suppression of immune system is the key to the development, progression and/or regression of cervical lesions. Therefore, the objective of this study is to compare the local immune response among HIV-seropositive and seronegative patients with cervical intraepithelial neoplasia regarding the expression of T lymphocytes (CD3+, CD4+ and CD8+), B lymphocytes (CD20+) and natural killers cells (CD56+) in the cervical stroma. A cross-sectional study of paraffin blocks containing cervical tissue after conization by the Loop Electrosurgical Excision Procedure (LEEP) from 47 HIV-seropositive and 38 seronegative patients with CIN. Cervical stroma immunohistochemistry was performed in the CIN area. The Fisher's exact test was used for the statistical analysis. When HIV-seropositive and seronegative women were compared, the seropositive women had a higher count of CD8+ T lymphocytes (52.1% versus 28.9%, P<0.04). Considering CIN degree (CIN 1 and CIN 2/3), the HIV-seronegative patients with CIN 1 had a low count of CD20+B-lymphocytes (7.1%) in comparison with CIN 1 HIV seropositive and with CIN 2/3 HIV-seronegative patients, respectively 50% (P<0.018) and 54.5% (P<0.0048). The HIV infection and degree of CIN influenced the cytotoxic lymphocytes inducing an increase in the number of cells high count of CD20+ lymphocytes with CIN 1. PMID:26545568

  9. Improved adipogenic in vitro differentiation: comparison of different adipogenic cell culture media on human fat and bone stroma cells for fat tissue engineering.

    PubMed

    Ghoniem, Amir-Alexander; Açil, Yahya; Wiltfang, Jörg; Gierloff, Matthias

    2015-06-01

    To date there is no sufficient in vitro fat tissue engineering and a protocol has not been well established for this purpose. Therefore, we evaluated the in vitro influence of two different adipogenic growth media for their stimulation potential on different cell lineages to clearly define the most potent adipogenic growth media for future in vitro tissue engineering approaches. The samples for differentiation were composed of human adipogenic-derived stroma cells (hADSCs) and human bone marrow mesenchymal stroma cells (hMSCs). A normal adipogenic medium (NAM) and a specific adipogenic medium (SAM) were tested for their adipogenic stimulation potential. After 10 days and 21 days the relative gene expression was measured for the adipogenic marker genes PPARγ2, C/EBPα, FABP4, LPL, and GLUT4 detected through real time reverse transcriptase polymease chain reaction (RT-PCR). Other study variables were the comparison between NAM and SAM and between the used cells hADSCs and hMSCs. Additionally an Oil-Red staining was performed after 21 days. Our results revealed that only SAM was significantly (P<0.05) superior in the differentiation process in contrast to NAM for 10 days and 21 days. As well was SAM superior to differentiate the used cell lineages. This was evaluated by the detected marker genes PPARγ2, C/EBPα, FABP4, LPL, and GLUT4 through real time RT-PCR and by Oil-Red staining. In addition, the hMSCs proofed to be equal donor cells for adipogenic differentiation especially when stimulated by SAM. The results suggest that the SAM should be established as a new standard medium for a more promising in vitro adipogenic differentiation. PMID:26140219

  10. Amino-Biphosphonate–Mediated MMP-9 Inhibition Breaks the Tumor-Bone Marrow Axis Responsible for Myeloid-Derived Suppressor Cell Expansion and Macrophage Infiltration in Tumor Stroma

    PubMed Central

    Melani, Cecilia; Sangaletti, Sabina; Barazzetta, Francesca M.; Werb, Zena; Colombo, Mario P.

    2009-01-01

    BALB-neuT mice expressing an activated rat c-erbB-2/neu transgene under the mouse mammary tumor virus long terminal repeat show enhanced hematopoiesis with hyperproduction of myeloid-derived suppressor cells (MDSC) because of vascular endothelial growth factor (VEGF) secreted by the tumor. Here, we show that both tumor and stromal cells express matrix metalloproteinase-9 (MMP-9), thereby increasing the levels of pro–MMP-9 in the sera of tumor-bearing mice. Treatment with amino-biphosphonates impaired tumor growth, significantly decreased MMP-9 expression and the number of macrophages in tumor stroma, and reduced MDSC expansion both in bone marrow and peripheral blood by dropping serum pro–MMP-9 and VEGF. We dissected the role of tumor-derived MMP-9 from that secreted by stromal leukocytes by transplanting bone marrow from MMP-9 knockout mice into BALB-neuT mice. Although bone marrow progenitor–derived MMP-9 had a major role in driving MDSC expansion, amino-biphosphonate treatment of bone marrow chimeras further reduced both myelopoiesis and the supportive tumor stroma, thus enhancing tumor necrosis. Moreover, by reducing MDSC, amino-biphosphonates overcome the tumor-induced immune suppression and improved the generation and maintenance of antitumor immune response induced by immunization against the p185/HER-2. Our data reveal that suppression of MMP-9 activity breaks the vicious loop linking tumor growth and myeloid cell expansion, thus reducing immunosuppression. Amino-biphosphonates disclose a specific MMP-9 inhibitory activity that may broaden their application above their current usage. PMID:18056472

  11. On the apparent CO2 absorption by alkaline soils

    NASA Astrophysics Data System (ADS)

    Chen, X.; Wang, W. F.

    2014-02-01

    Alkaline soils in the Gubantonggut Desert were recently demonstrated socking away large quantities of CO2 in an abiotic form. This demands a better understanding of abiotic CO2 exchange in alkaline sites. Reaction of CO2 with the moisture or dew in the soil was conjectured as a potential mechanism. The main goal of this study is to determine the extent to which the dew deposition modulates Land-Atmosphere CO2 exchange at highly alkaline sites (pH ~ 10). Experiments were conducted at the most barren sites (canopy coverage < 5%) to cut down uncertainty. Dew quantities and soil CO2 fluxes were measured using a micro-lysimeters and an automated flux system (LI-COR, Lincoln, Nebraska, USA), respectively. There is an evident increase of dew deposition in nocturnal colder temperatures and decrease in diurnal warmer temperatures. Variations of soil CO2 flux are almost contrary, but the increase in diurnal warmer temperatures is obscure. It was shown that the accumulation and evaporation of dew in the soil motivates the apparent absorption and release of CO2. It was demonstrated that dew amounts in the soil has an exponential relation with the part in Fc beyond explanations of the worldwide utilized Q10 model. Therefore dew deposition in highly alkaline soils exerted a potential CO2 sink and can partly explain the apparent CO2 absorption. This implied a crucial component in the net ecosystem carbon balance (NECB) at alkaline sites which occupies approximately 5% of the Earth's land surface (7 million km). Further explorations for its mechanisms and representativeness over other arid climate systems have comprehensive perspectives in the quaternary research.

  12. Apparent threshold of lead's effect on child intelligence

    SciTech Connect

    Rabinowitz, M.B. National Taiwan Univ., Taipei ); Wang, J.D.; Soong, W.T. )

    1992-05-01

    The developing human brain is perhaps the most sensitive of the many targets of lead toxicity. This particular sensitivity is a driving factor in setting health and environmental standards for lead. A recent compilation of studies of the association between lead and IQ has shown a consistent dose-response pattern across the range of reported exposures. In surveying the neurotoxicity of lead in humans and animals, there has been speculation of the existence of a threshold for these effects which may become apparent at lower lead levels. In that context we examined our data of tooth lead and IQ scores to determine whether there was any apparent threshold for this effect. This cohort's lead levels are among the lowest documented and provide the opportunity to extend downward the range of interest. Family factors are the strongest predictors of a child's intelligence, in particular the parent's intelligence. We therefore followed the model of Perino and Ernhart (1974) by examining whether at various levels of lead there is a disruption of the usual association between family and child intelligence. As noted by Bellinger and Needleman (1983), a difference in the correlations between parental and child intelligence in two groups, high and low lead, may be an artifact of other relationships among the predictor variables. Accordingly, they recommend a more appropriate test that would search for differences in the IQ deficits according to lead level, where the IQ deficit is the difference between a child's observed IQ and the IQ predicted from all available information about the child aside from lead. This is especially appropriate when the lead exposure correlates with the family's educational background. We examined our data this way. 12 refs., 1 fig., 2 tabs.

  13. An apparent mechanism dependence of radiated seismic energy

    NASA Astrophysics Data System (ADS)

    PéRez-Campos, Xyoli; Beroza, Gregory C.

    2001-06-01

    We develop an extension to the method of Boatwright and Choy [1986] for determining the radiated seismic energy Es that accounts for factors that bias the estimate. We apply our technique to 204 events worldwide during the period 1992-1999 and find that the apparent stress is on average largest for strike-slip events (0.70 MPa), while for reverse and normal events it is significantly smaller (0.15 and 0.25 MPa, respectively). These results support the mechanism dependence of Es reported by Choy and Boatwright [1995], although we find that once likely sources of bias are accounted for, the mechanism dependence is not as strong as found previously. The source of the mechanism dependence is unclear, but one possibility is that it reflects a mechanism-dependent difference in the stress drop. This hypothesis is suggested by the scaling of slip with width in large strike-slip earthquakes and makes two predictions, which could be used to test it. The first is that the discrepancy should disappear for the very largest dip-slip earthquakes as the length of the fault greatly exceeds the downdip extent. The second is that the discrepancy ought to disappear for smaller earthquakes. The first can not yet be tested due to a lack of recent, very large dip-slip earthquakes. The second is supported by the lack of mechanism dependence to Es for smaller earthquakes. An alternative hypothesis is that the apparent mechanism dependence could result if faults are opaque during rupture, blocking seismic radiation across them [Brune, 1996]. This could cause radiated seismic energy to be trapped preferentially in the crust near the source volume for dipping faults. There remains, however, a large discrepancy between estimates of Es obtained from teleseismic versus regional data. This discrepancy indicates a problem with teleseismic and/or regional estimates of the seismic energy and must be resolved before a definite conclusion can be drawn.

  14. The apparent anomalous, weak, long-range acceleration of Pioneer 10 and 11

    SciTech Connect

    Anderson, J.D.; Lau, E.L.; Turyshev, S.G.; Laing, P.A.; Liu, A.S.; Nieto, M.M.

    1999-07-01

    Recently the authors reported that radio Doppler data generated by NASA`s Deep Space Network (DSN) with the Pioneer 10 and 11 spacecraft indicate an apparent anomalous, constant, spacecraft acceleration with a magnitude {approximately}8.5 {times} 10{sup {minus}8} cm s{sup {minus}2}, directed towards the Sun. Analysis of similar Doppler and ranging data from the Galileo and Ulysses spacecraft yielded ambiguous results for the anomalous acceleration, but the analysis was useful in that it ruled out the possibility of a systematic error in the DSN Doppler system that could easily be mistaken as a spacecraft acceleration. Here they present some new results, including a critique of the suggestion that the anomalous acceleration could be caused by collimated thermal emission. Based on upgraded JPL software for the Pioneer 10 orbit determination, and on a new data interval from January 1987 to July 1998, their best estimate of the average Pioneer 10 acceleration directed towards the Sun is 7.20 {sup {minus}} 0.11 {times} 10{sup {minus}8} cm s{sup {minus}2}.

  15. The deep oval window.

    PubMed

    Kapur, T R

    1991-09-01

    This article presents the results of an analysis of the variable and surgically important relationship between the oval window, the fossular walls and the related posterior tympanic recesses in 50 temporal bones. The visual impressions of superficial and deep oval windows seem to correspond fairly closely to the depth of the inferior wall of the fossula fenestra vestibuli (FFV). The depth of the superior and anterior walls of the FFV by themselves, did not appear to have such a dominating relationship in determining the deep oval window. There does not appear to be a well defined posterior wall in the vast majority of the specimens (86 per cent). In the event of scar tissue forming between the superior, inferior and anterior walls, the gap between the postero-superior part of the promontory and the posterior tympanic wall (posterior communication) could allow aeration of the region of the deep oval window in such an instance. Closure of this gap by a solid shelf of ponticulus or scar tissue could cause a localized malaeration of the fossula in most cases of deep oval windows. This is an entirely new concept of the likely problems of malaeration of a deep oval window which could arise due to anatomical variations and of the possible safety valve mechanism which could prevent such malaeration and its consequences. PMID:1919338

  16. Histological and immunohistochemical evaluation of stroma variations and their correlation with the Ki-67 index and expressions of glucose transporter 1 and monocarboxylate transporter 1 in canine thyroid C-cell carcinomas.

    PubMed

    Kawamura, Yoshio; Mizooku, Hiroko; Okamoto, Minoru; Matsuda, Kazuya; Omachi, Tetsuo; Hirayama, Kazuko; Kadosawa, Tsuyoshi; Taniyama, Hiroyuki

    2016-05-01

    Canine thyroid C-cell carcinomas (CTCCs) are malignant tumors derived from calcitonin-producing C-cells of the thyroid gland. This study aimed to investigate the histological diversity of CTCCs from the viewpoint of stroma variations and to investigate their components by histological and immunohistochemical analyses including semiquantitative analysis of the density of microvessels (MVs) and α-SMA-positive cell count. Moreover, we examined whether the variations correlated with the Ki-67 index and expressions of glucose transporter 1 (GLUT-1) and monocarboxylate transporter 1 (MCT-1). Three stroma types (reticular, R, nest, N, and trabecular, T) were observed in CTCCs, and 21 cases were divided into 3 variations based on their combinations: mixed R and N (R/N) (n=7), simple N (n=7) and mixed T and N (T/N) (n=7). Immunohistochemically, stroma types depended on morphological features of α-SMA/fibronectin/laminin/collagen type IV-positive stroma cells. The density of MVs in R/N tended to be highest, and the density of those in N was significantly higher than the density of those in T/N (P=0.028). The α-SMA-positive cell count for N tended to be the lowest among the 3 variations. The Ki-67 index for R/N was significantly higher than those of the other variations (vs. N, P=0.007; vs. T/N, P=0.03), and that for T/N tended to be higher than that for N. Although there were no significant differences, GLUT-1 and MCT-1 expressions tended to be low in N. We concluded that stroma variations reflect tumor cell proliferation and expressions of GLUT-1 and MCT-1 in CTCCs. PMID:26726103

  17. Histological and immunohistochemical evaluation of stroma variations and their correlation with the Ki-67 index and expressions of glucose transporter 1 and monocarboxylate transporter 1 in canine thyroid C-cell carcinomas

    PubMed Central

    KAWAMURA, Yoshio; MIZOOKU, Hiroko; OKAMOTO, Minoru; MATSUDA, Kazuya; OMACHI, Tetsuo; HIRAYAMA, Kazuko; KADOSAWA, Tsuyoshi; TANIYAMA, Hiroyuki

    2016-01-01

    Canine thyroid C-cell carcinomas (CTCCs) are malignant tumors derived from calcitonin-producing C-cells of the thyroid gland. This study aimed to investigate the histological diversity of CTCCs from the viewpoint of stroma variations and to investigate their components by histological and immunohistochemical analyses including semiquantitative analysis of the density of microvessels (MVs) and α-SMA-positive cell count. Moreover, we examined whether the variations correlated with the Ki-67 index and expressions of glucose transporter 1 (GLUT-1) and monocarboxylate transporter 1 (MCT-1). Three stroma types (reticular, R, nest, N, and trabecular, T) were observed in CTCCs, and 21 cases were divided into 3 variations based on their combinations: mixed R and N (R/N) (n=7), simple N (n=7) and mixed T and N (T/N) (n=7). Immunohistochemically, stroma types depended on morphological features of α-SMA/fibronectin/laminin/collagen type IV-positive stroma cells. The density of MVs in R/N tended to be highest, and the density of those in N was significantly higher than the density of those in T/N (P=0.028). The α-SMA-positive cell count for N tended to be the lowest among the 3 variations. The Ki-67 index for R/N was significantly higher than those of the other variations (vs. N, P=0.007; vs. T/N, P=0.03), and that for T/N tended to be higher than that for N. Although there were no significant differences, GLUT-1 and MCT-1 expressions tended to be low in N. We concluded that stroma variations reflect tumor cell proliferation and expressions of GLUT-1 and MCT-1 in CTCCs. PMID:26726103

  18. Immunohistochemical analysis of steroidogenic enzymes in ovarian-type stroma of pancreatic mucinous cystic neoplasms: Comparative study of subepithelial stromal cells in intraductal papillary mucinous neoplasms of the pancreas.

    PubMed

    Ishida, Kazuyuki; Sasano, Hironobu; Moriya, Takuya; Takahashi, Yayoi; Sugimoto, Ryo; Mue, Yoshiharu; Murakami, Keigo; Fujishima, Fumiyoshi; Nakamura, Yasuhiro; Morikawa, Takanori; Motoi, Fuyuhiko; Suzuki, Takashi; Unno, Michiaki; Sugai, Tamotsu

    2016-05-01

    Mucinous cystic neoplasms (MCNs) are generally defined as cyst-forming epithelial neoplasms that arise in the pancreas and harbor characteristic ovarian-type stroma beneath the epithelium. In this study, we compared the immunoreactivity of steroid-related factors in these subepithelial stromal cells in MCNs to those in intraductal papillary mucinous neoplasms (IPMNs) to further characterize this unique MCN ovarian-type stroma through evaluation of sex steroid biosynthesis. Twenty MCNs and twenty IPMNs were examined. Immunoreactivity of steroid hormone receptors, including estrogen receptor (ERα and ERβ), progesterone receptor (PR, PR-A, and PR-B), and androgen receptor (AR), was more frequently detected in MCN ovarian-type stromal cells than in IPMN stromal cells (P < 0.01). The H-scores (mean ± SD) of steroidogenic factor (SF)-1 were also significantly higher in MCNs (112.3 ± 33.1) than in IPMNs (0.9 ± 1.2) (P < 0.01). The steroidogenic enzymes cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc), cytochrome P450 17 alpha-hydroxylase (P450c17) and 3β-hydroxysteroid dehydrogenase (3β-HSD) showed immunoreactivity in 9/20 (45.0 %), 15/20 (75.0 %) and 13/20 (65.0 %), respectively, of ovarian-type stroma from MCN cases. These results demonstrate that the ovarian-type stroma of MCNs can express steroidogenic enzymes. Thus, the ovarian-type stroma of MCNs can produce sex steroids that may also act on these cells. PMID:27060902

  19. Contribution of Chlorophyll Fluorescence to the Apparent Reflectance of Vegetation

    NASA Technical Reports Server (NTRS)

    Campbell, P. K. Entcheva; Middleton, E. M.; Kim, M. S.

    2007-01-01

    Current strategies for monitoring the physiologic status of terrestrial vegetation rely on remote sensing reflectance (R) measurements, whi ch provide estimates of relative vegetation vigor based primarily on chlorophyll content. Vegetation chlorophyll fluorescence (CF) offers a non-destructive alternative and a more direct approach for diagnosis of vegetation stress before a significant reduction in chlorophyll content has occurred. Thus, monitoring of vegetation vigor based on CF may allow earlier stress detection and more accurate carbon sequestra tion estimates, than is possible using R data alone. However, the observed apparent vegetation reflectance (Ra) in reality includes contrib utions from both the reflected and fluoresced radiation. The aim of t his study is to determine the relative R and CF fractions contributing to Ra from the vegetation in the red to near-infrared region of the spectrum. The practical objectives of the study are to: 1) evaluate t he relationship between CF and R at the foliar level for corn, soybean, maple; and 2) for corn, determine if the relationship established f or healthy (optimal N) vegetation changes under N defiiency. To obtai n generally applicable results, experimental measurements were conducted on unrelated crop and tree species (maple, soybean and corn), unde r controlled conditions and a gradient of inorganic N fertilization l evels. Optical R spectra and actively induced CF emissions were obtained on the same foliar samples, in conjunction with measurements of p hotosynthetic function, pigment levels, and C and N content. The comm on spectral trends or similarities were examined. On average, 10-20% of apparent R at 685 nm was actually due to CF. The spectral trends in steady and maximum F varied significantly, with Fs (especially red) showing higher ability for species and treatment separation. The relative contribution of ChF to R varied significantly among species, with maple emitting much higher F amounts, as

  20. Variations of apparent target position due to refraction

    NASA Astrophysics Data System (ADS)

    Seiffer, Dirk; Stein, Karin

    2005-10-01

    The performance of Electro-Optical systems operating within the marine boundary layer is severely influenced by atmospheric conditions. Vertical temperature and humidity gradients lead to refraction and turbulence effects. Refraction causes focusing and defocusing of rays, detection range limitations, mirage formation and angular deviation. Associated with the VAMPIRA (Validation Measurement on Propagation in the IR and Radar) experiment, we made investigations on the apparent elevations of point targets. The location of the trial was at the coast line of the Baltic Sea, overlooking a bay. An IR camera system was fixed on a pier at an altitude of 6.5 m. The camera continuously recorded a series of lights 8.2 km away at the other side of the bay. With these recordings we obtained 24-hours-observations of refraction effects due to changing weather conditions. In addition to the VAMPIRA measurements a similar experiment was performed in tropical waters. First results of this trial are given here. Aim of this paper is to discuss and analyse the measured elevations and compare them to the propagation model IRBLEM (IR Boundary Layer Effects Model by DRDC, Canada).

  1. Apparent thermal conductivity measurements by an unguarded technique

    NASA Astrophysics Data System (ADS)

    Graves, R. S.; Yarbrough, D. W.; McElroy, D. L.

    An unguarded longitudinal heat flow apparatus for measuring the apparent thermal conductivity (lambda/sub a) of insulations was tested. Heat flow is provided by a horizontal electrically heated Nichrome screen sandwiched between test samples that are bounded by temperature controlled copper plates and 9 cm of mineral fiber insulation. A determinate error analysis shows lambda/sub a/ measurement uncertainty to be less than + or - 1.7% for insulating materials as thin as 3 cm. Three-dimensional thermal modeling indicates negligible error in lambda/sub a/ due to edge loss for insulations up to 7.62 cm thick when the temperature difference across the sample is measured at the screen center. System repeatability and reproducibility were determined to be + or - 0.2%. Differences of lambda/sub a/ results from the screen tester and results from the National Bureau of Standards were 0.1% for a 10-kg/m(3) Calibration Transfer Standard and 0.9% for 127-kg/m(3) fibrous glass board (SRM 1450b). Measurements on fiberglass and rock wool batt insulations showed the dependence of lambda/sub a/ on density, temperature, temperature difference, plate emittance, and heat flow direction. Results obtained for lambda/sub a/ as a function of density at 240C differed by less than 2% from values obtained with a guarded hot plate. It is demonstrated that this simple technique has the accuracy and sensitivity needed for useful lambda/sub a/ measurements on thermal insulating materials.

  2. Apparent Transition Behavior of Widely-Used Turbulence Models

    NASA Technical Reports Server (NTRS)

    Rumsey, Christopher L.

    2007-01-01

    The Spalart-Allmaras and the Menter SST k-omega turbulence models are shown to have the undesirable characteristic that, for fully turbulent computations, a transition region can occur whose extent varies with grid density. Extremely fine two-dimensional grids over the front portion of an airfoil are used to demonstrate the effect. As the grid density is increased, the laminar region near the nose becomes larger. In the Spalart-Allmaras model this behavior is due to convergence to a laminar-behavior fixed point that occurs in practice when freestream turbulence is below some threshold. It is the result of a feature purposefully added to the original model in conjunction with a special trip function. This degenerate fixed point can also cause non-uniqueness regarding where transition initiates on a given grid. Consistent fully turbulent results can easily be achieved by either using a higher freestream turbulence level or by making a simple change to one of the model constants. Two-equation k-omega models, including the SST model, exhibit strong sensitivity to numerical resolution near the area where turbulence initiates. Thus, inconsistent apparent transition behavior with grid refinement in this case does not appear to stem from the presence of a degenerate fixed point. Rather, it is a fundamental property of the k-omega model itself, and is not easily remedied.

  3. Earths Climate Sensitivity: Apparent Inconsistencies in Recent Assessments

    SciTech Connect

    Schwartz, Stephen E.; Charlson, Robert J.; Kahn, Ralph; Rodhe, Henning

    2014-12-08

    Earth's equilibrium climate sensitivity (ECS) and forcing of Earth's climate system over the industrial era have been re-examined in two new assessments: the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC), and a study by Otto et al. (2013). The ranges of these quantities given in these assessments and also in the Fourth (2007) IPCC Assessment are analyzed here within the framework of a planetary energy balance model, taking into account the observed increase in global mean surface temperature over the instrumental record together with best estimates of the rate of increase of planetary heat content. This analysis shows systematic differences among the several assessments and apparent inconsistencies within individual assessments. Importantly, the likely range of ECS to doubled CO₂ given in AR5, 1.5–4.5 K/(3.7 W m⁻²) exceeds the range inferred from the assessed likely range of forcing, 1.2–2.9 K/(3.7 W m⁻²), where 3.7 W ⁻² denotes the forcing for doubled CO₂. Such differences underscore the need to identify their causes and reduce the underlying uncertainties. Explanations might involve underestimated negative aerosol forcing, overestimated total forcing, overestimated climate sensitivity, poorly constrained ocean heating, limitations of the energy balance model, or a combination of effects.

  4. Switch hitting in baseball: apparent rule-following, not matching.

    PubMed

    Poling, Alan; Weeden, Marc A; Redner, Ryan; Foster, T Mary

    2011-09-01

    Many studies, including some dealing with shot selection in basketball and play selection in football, demonstrate that the generalized matching equation provides a good description of the allocation of time and effort to alternative responses as a function of the consequences of those alternatives. We examined whether it did so with respect to left- and right-handed at bats (alternative responses) and left- and right-handed total bases earned, runs batted in, and home runs (three consequences) for the outstanding baseball switch-hitters Mickey Mantle, Eddie Murray, and Pete Rose. With all hitters, undermatching, suggesting insensitivity to the consequences of behavior (reinforcement), was evident and there was substantial bias towards left-handed at bats. These players apparently chose handedness based on the rule "bat opposite the pitcher," not on differential consequences obtained in major league games. The present findings are significant in representing a counter-instance of demonstrations of a matching relationship in sports in particular and in human behavior in general and in calling attention to the need for further study of the variables that affect choice. PMID:21909169

  5. Earth's Climate Sensitivity: Apparent Inconsistencies in Recent Assessments

    NASA Astrophysics Data System (ADS)

    Schwartz, Stephen E.; Charlson, Robert J.; Kahn, Ralph; Rodhe, Henning

    2014-12-01

    Earth's equilibrium climate sensitivity (ECS) and forcing of Earth's climate system over the industrial era have been re-examined in two new assessments: the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC), and a study by Otto et al. (2013). The ranges of these quantities given in these assessments and also in the Fourth (2007) IPCC Assessment are analyzed here within the framework of a planetary energy balance model, taking into account the observed increase in global mean surface temperature over the instrumental record together with best estimates of the rate of increase of planetary heat content. This analysis shows systematic differences among the several assessments and apparent inconsistencies within individual assessments. Importantly, the likely range of ECS to doubled CO2 given in AR5, 1.5-4.5 K/(3.7 W m-2) exceeds the range inferred from the assessed likely range of forcing, 1.2-2.9 K/(3.7 W m-2), where 3.7 W m-2 denotes the forcing for doubled CO2. Such differences underscore the need to identify their causes and reduce the underlying uncertainties. Explanations might involve underestimated negative aerosol forcing, overestimated total forcing, overestimated climate sensitivity, poorly constrained ocean heating, limitations of the energy balance model, or a combination of effects.

  6. Knoop Hardness - Apparent Yield Stress Relationship in Ceramics

    SciTech Connect

    Swab, Jeffrey J; LaSalvia, Jerry; Wereszczak, Andrew A; Strong, Kevin T; Danna, Dominic; Ragan, Meredith E; Ritt, Patrick J

    2012-01-01

    In Tabor's classical studies of the deformation of metals, the yield stress (Y) and hardness (H) were shown to be related according to H/Y {approx} 3 for complete or fully plastic deformation. Since then it has been anecdotally shown for ceramics that this ratio is <3. Interest exists to explore this further so Hertzian indentation was used to measure the apparent yield stress of numerous ceramics and metals and their results were compared with each material's load-dependent Knoop hardness. The evaluated ceramics included standard reference materials for hardness (silicon nitride and tungsten carbide), silicon carbide, alumina, and glass. Several steel compositions were also tested for comparison. Knoop hardness measurements at 19.6 N (i.e., toward 'complete or fully plastic deformation'), showed that 2 < H/Y < 3 for the metals and 0.8 < H/Y < 1.8 for the glasses and ceramics. Being that H/Y {ne} 3 for the ceramics indicates that Tabor's analysis is either not applicable to ceramics or that full plastic deformation is not achieved with a Knoop indentation or both.

  7. Image statistics and the perception of apparent motion.

    PubMed

    Gilden, D L; Bertenthal, B I; Othman, S

    1990-11-01

    The short- and long-range apparent motion processes are discussed in terms of the statistical properties of images. It is argued that the short-range process, exemplified by the random-dot kinematogram, is primarily sensitive to the dipole statistics, whereas the long-range process, exemplified by illusory occlusion, is treated by the visual system primarily in terms of the tripole and higher statistical correlation functions. The studies incorporate the balanced dot, which is a unique stimulus element that permits high pass filtering while preserving detailed positional information. Low spatial frequencies are shown to be critical for texture segregation in random-dot kinematograms, independent of the grain size or number density of texture elements. Illusory path perception in the long-range process is shown not to require low spatial frequencies, but is sensitive rather to global temporal phase coherency. These results are interpreted in terms of the respective roles of the power and phase spectra in perceptual organization. The construction of balanced dots is discussed in detail. PMID:2148586

  8. Estimating phosphorus concentrations following alum treatment using apparent settling velocity

    USGS Publications Warehouse

    Panuska, John; Robertson, Dale M.

    2009-01-01

    he apparent settling velocity (Vs) is a term used in empirical, steady-state, mass-balance lake models to represent the net phosphorus flux from the water column. The Vollenweider (1969) mixed-reactor lake model was rearranged and used to calculate Vs values for total phosphorus (TP) for three lakes treated with alum to reduce the internal flux of P to the water column (Delavan Lake, Wisconsin; Lake Morey, Vermont; and West Twin Lake, Ohio). An analysis of Vs values was conducted using data from these three lakes for both the pre- and post-alum treated conditions. Analysis of Vs values for both the pre- and post-alum conditions in Lake Morey and West Twin Lake resulted in a post-treatment mean Vs value of 7 ± 2.0 m·yr−1. The effect of the alum treatment, although short-lived in Delavan Lake, resulted in a mean post-treatment Vs value of 3.4 ± 0.3 m·yr−1. The consistency in the post-treatment Vs values in Lake Morey and West Twin Lake is used to demonstrate a predictive analysis method for water column TP concentrations in lakes following a successful treatment of the anoxic sediment area with alum. Additional pre- and post-alum in-lake and watershed loading data are needed to advance this concept into a management model.

  9. Ultrasonic characterization of cancellous bone using apparent integrated backscatter

    NASA Astrophysics Data System (ADS)

    Hoffmeister, B. K.; Jones, C. I., III; Caldwell, G. J.; Kaste, S. C.

    2006-06-01

    Apparent integrated backscatter (AIB) is a measure of the frequency-averaged (integrated) backscattered power contained in some portion of a backscattered ultrasonic signal. AIB has been used extensively to study soft tissues, but its usefulness as a tissue characterization technique for cancellous bone has not been demonstrated. To address this, we performed measurements on 17 specimens of cancellous bone over two different frequency ranges using a 1 MHz and 5 MHz broadband ultrasonic transducer. Specimens were obtained from bovine tibiae and prepared in the shape of cubes (15 mm side length) with faces oriented along transverse (anterior, posterior, medial and lateral) and longitudinal (superior and inferior) principal anatomic directions. A mechanical scanning system was used to acquire multiple backscatter signals from each direction for each cube. AIB demonstrated highly significant linear correlations with bone mineral density (BMD) for both the transverse (R2 = 0.817) and longitudinal (R2 = 0.488) directions using the 5 MHz transducer. In contrast, the correlations with density were much weaker for the 1 MHz transducer (R2 = 0.007 transverse, R2 = 0.228 longitudinal). In all cases where a significant correlation was observed, AIB was found to decrease with increasing BMD.

  10. Apparent Transition Behavior of Widely-Used Turbulence Models

    NASA Technical Reports Server (NTRS)

    Rumsey, Christopher L.

    2006-01-01

    The Spalart-Allmaras and the Menter SST kappa-omega turbulence models are shown to have the undesirable characteristic that, for fully turbulent computations, a transition region can occur whose extent varies with grid density. Extremely fine two-dimensional grids over the front portion of an airfoil are used to demonstrate the effect. As the grid density is increased, the laminar region near the nose becomes larger. In the Spalart-Allmaras model this behavior is due to convergence to a laminar-behavior fixed point that occurs in practice when freestream turbulence is below some threshold. It is the result of a feature purposefully added to the original model in conjunction with a special trip function. This degenerate fixed point can also cause nonuniqueness regarding where transition initiates on a given grid. Consistent fully turbulent results can easily be achieved by either using a higher freestream turbulence level or by making a simple change to one of the model constants. Two-equation kappa-omega models, including the SST model, exhibit strong sensitivity to numerical resolution near the area where turbulence initiates. Thus, inconsistent apparent transition behavior with grid refinement in this case does not appear to stem from the presence of a degenerate fixed point. Rather, it is a fundamental property of the kappa-omega model itself, and is not easily remedied.

  11. OH Column Abundance Apparent Response to Solar Cycle 23

    NASA Astrophysics Data System (ADS)

    Burnett, C. R.; Minschwaner, K. R.

    2009-12-01

    The 33-year series of high spectral resolution measurements of absorption of sunlight by OH at 308 nm has exhibited temporary decreases of column abundances in 1986, 1997, and 2008 near the times of minimum solar activity. These observations and analyses are of significance as they encompass three complete solar cycles for comparison. During solar cycle 23, the annual average abundances increased approximately 20% from the minimum abundance in 1997 to high-sun enhanced values in 2000-2006, then dropped approximately 15% in 2008. The abundances exhibited a pronounced reduction at solar minimum in August-October 2008, similar to that seen in fall 1986 and fall 1997. The average morning abundances on those occasions were 13% smaller than the 1980-88 corresponding average, about 0.9 x 1013 cm-2, with minimum values broadly consistent with model results. In contrast, high-sun OH abundances observed during periods of solar maximum are approximately 33% larger than modeled abundances. This discrepancy cannot be explained by reasonable adjustments of reaction rates or modeled constituent concentrations in the stratosphere or mesosphere. However, the observed responses to a tropopause fold event in 1988 and to the Pinatubo aerosol in 1991 do suggest an important contribution to the total OH column from the lower stratosphere. In addition to the apparent variations with solar activity, this OH column database contains a number of other effects such as diurnal and seasonal patterns, and geographic differences between observations from Colorado, Florida, Alaska, Micronesia, New Zealand, and New Mexico.

  12. Tuning for temporal interval in human apparent motion detection.

    PubMed

    Bours, Roger J E; Stuur, Sanne; Lankheet, Martin J M

    2007-01-01

    Detection of apparent motion in random dot patterns requires correlation across time and space. It has been difficult to study the temporal requirements for the correlation step because motion detection also depends on temporal filtering preceding correlation and on integration at the next levels. To specifically study tuning for temporal interval in the correlation step, we performed an experiment in which prefiltering and postintegration were held constant and in which we used a motion stimulus containing coherent motion for a single interval value only. The stimulus consisted of a sparse random dot pattern in which each dot was presented in two frames only, separated by a specified interval. On each frame, half of the dots were refreshed and the other half was a displaced reincarnation of the pattern generated one or several frames earlier. Motion energy statistics in such a stimulus do not vary from frame to frame, and the directional bias in spatiotemporal correlations is similar for different interval settings. We measured coherence thresholds for left-right direction discrimination by varying motion coherence levels in a Quest staircase procedure, as a function of both step size and interval. Results show that highest sensitivity was found for an interval of 17-42 ms, irrespective of viewing distance. The falloff at longer intervals was much sharper than previously described. Tuning for temporal interval was largely, but not completely, independent of step size. The optimal temporal interval slightly decreased with increasing step size. Similarly, the optimal step size decreased with increasing temporal interval. PMID:17461670

  13. Detection of betanodaviruses in apparently healthy aquarium fishes and invertebrates

    PubMed Central

    Gomez, Dennis Kaw; Lim, Dong Joo; Baeck, Gun Wook; Youn, Hee Jeong; Shin, Nam Shik; Youn, Hwa Young; Hwang, Cheol Yong; Park, Jun Hong

    2006-01-01

    Betanodaviruses are the causative agents of viral nervous necrosis (VNN) in cultured marine fish. A total of 237 apparently healthy aquarium fish, marine (65 species) and freshwater (12 species) fishes and marine invertebrates (4 species), which were stocked in a commercial aquarium in Seoul, South Korea, were collected from November 2005 to February 2006. The brains of the fish and other tissues of the invertebrates were examined by reverse transcriptase-polymerase chain reaction (RT-PCR) and nested PCR to detect betanodavirus. Positive nested PCR results were obtained from the brains of 8 marine fish species (shrimp fish Aeoliscus strigatus, milkfish Chanos chanos, three spot damsel Dascyllus trimaculatus, Japanese anchovy Engraulis japonicus, pinecone fish Monocentris japonica, blue ribbon eel Rhinomuraena quaesita, look down fish Selene vomer, yellow tang Zebrasoma flavesenes), 1 marine invertebrate species (spiny lobster Pamulirus versicolor), and 2 freshwater fish species (South American leaf fish Monocirrhus polyacanthus and red piranha Pygocentrus nattereri). The detection rate in nested PCR was 11/237 (4.64%). These subclinically infected aquarium fish and invertebrates may constitute an inoculum source of betanodaviruses for cultured fishes in the Korean Peninsula. PMID:17106229

  14. Short-duration radio bursts with apparent extragalactic dispersion

    SciTech Connect

    Saint-Hilaire, P.; Benz, A. O.; Monstein, C.

    2014-11-01

    We present the results of the longest yet undertaken search for apparently extragalactic radio bursts at the Bleien Radio Observatory covering 21,000 hr (898 days). The data were searched for events of less than 50 ms FWHM duration showing a ν{sup –2} drift in the spectrogram characteristic of the delay of radio waves in plasma. We have found five cases suggesting dispersion measures between 350 and 400 cm{sup –3} pc while searching in the range of 75-2000 cm{sup –3} pc. Four of the five events occurred between 10:27 and 11:24 a.m. local civil time. The only exception occurred at night with the full Moon in the beam. It was an event that poorly fits plasma dispersion, but had the characteristics of a solar Type III burst. However, we were not able to confirm that it was a lunar reflection. All events were observed with a log-periodic dipole within 6800 hr, but none with a more directional horn antenna observing the rest of the time. These properties suggest a terrestrial origin of the 'peryton' type reported before. However, the cause of these events remains ambiguous.

  15. Spatial and temporal context affects correspondences in apparent motion

    NASA Astrophysics Data System (ADS)

    Anstis, Stuart

    1989-01-01

    Apparent motion (AM) is seen when two patterns (such as movie frames) are exposed in succession in nearby positions. How does the visual system solve the "correspondence problem", that is, decide which item in the second frame is to be paired off with a given item in the first frame? We used a four-spot ambiguous AM display to reveal the influence of additional spots exposed nearby in space or in time. Spots that are close to each other tend to be paired off by proximity. AM is seen preferentially within the same hemiretina, that is within the same half of the brain, rather than across the retinal midline. AM in a straight line is strongly preferred over a bent path. Unambiguous AM drags an ambiguous nearby AM with it. An array of identical ambiguous AMs all move together, not independently. We also describe entrained AM, and perceptual suppression of the spurious motion signals originating in static background items that are covered and uncovered by an object moving in front of them. All these phenomena demonstrate the role of parsimony and of minimum principles in motion perception.

  16. Altered perception of apparent motion in schizophrenia spectrum disorder.

    PubMed

    Tschacher, Wolfgang; Dubouloz, Priscilla; Meier, Rahel; Junghan, Uli

    2008-06-30

    Apparent motion (AM), the Gestalt perception of motion in the absence of physical motion, was used to study perceptual organization and neurocognitive binding in schizophrenia. Associations between AM perception and psychopathology as well as meaningful subgroups were sought. Circular and stroboscopic AM stimuli were presented to 68 schizophrenia spectrum patients and healthy participants. Psychopathology was measured using the Positive and Negative Syndrome Scale (PANSS). Psychopathology was related to AM perception differentially: Positive and disorganization symptoms were linked to reduced gestalt stability; negative symptoms, excitement and depression had opposite regression weights. Dimensions of psychopathology thus have opposing effects on gestalt perception. It was generally found that AM perception was closely associated with psychopathology. No difference existed between patients and controls, but two latent classes were found. Class A members who had low levels of AM stability made up the majority of inpatients and control subjects; such participants were generally young and male, with short reaction times. Class B typically contained outpatients and some control subjects; participants in class B were older and showed longer reaction times. Hence AM perceptual dysfunctions are not specific for schizophrenia, yet AM may be a promising stage marker. PMID:18471894

  17. Switch Hitting in Baseball: Apparent Rule-following, not Matching

    PubMed Central

    Poling, Alan; Weeden, Marc A; Redner, Ryan; Foster, T. Mary

    2011-01-01

    Many studies, including some dealing with shot selection in basketball and play selection in football, demonstrate that the generalized matching equation provides a good description of the allocation of time and effort to alternative responses as a function of the consequences of those alternatives. We examined whether it did so with respect to left- and right-handed at bats (alternative responses) and left- and right-handed total bases earned, runs batted in, and home runs (three consequences) for the outstanding baseball switch-hitters Mickey Mantle, Eddie Murray, and Pete Rose. With all hitters, undermatching, suggesting insensitivity to the consequences of behavior (reinforcement), was evident and there was substantial bias towards left-handed at bats. These players apparently chose handedness based on the rule “bat opposite the pitcher,” not on differential consequences obtained in major league games. The present findings are significant in representing a counter-instance of demonstrations of a matching relationship in sports in particular and in human behavior in general and in calling attention to the need for further study of the variables that affect choice. PMID:21909169

  18. Use of photoluminescence to investigate apparent suicides by firearms.

    PubMed

    Loper, G L; Calloway, A R; Stamps, M A; Wolten, G M; Jones, P F

    1981-04-01

    A photoluminescence technique, which detects lead and antimony in gunshot residue, was evaluated for use in investigations of apparent gunshot suicides. The study was conducted in conjunction with forensic science laboratories in five U.S. cities. Samples were collected by the adhesive lift method from the backs of the hands of 67 gunshot suicide victims, 41 subjects who died of other causes, and 31 live subjects with high occupational exposure to lead and antimony. Tentative simultaneous threshold levels of 0.85 microgram for lead and 0.01 microgram for antimony were selected as criteria for presuming the presence of gunshot residue on samples from the hands of these suicide victims. Although blood decreases the detectability of lead and antimony in the samples, 48% of the suicide cases involving handguns other than .22 revolvers exceeded the threshold levels for both lead and antimony. Methods are suggested for eliminating the effects of blood, which should significantly increase the success rate for cases involving these guns. A much lower success rate was obtained for cases involving .22 revolvers and long guns, as expected from the sparse amounts of residue found in previous test firings of these guns. PMID:7264582

  19. Detection of betanodaviruses in apparently healthy aquarium fishes and invertebrates.

    PubMed

    Gomez, Dennis Kaw; Lim, Dong Joo; Baeck, Gun Wook; Youn, Hee Jeong; Shin, Nam Shik; Youn, Hwa Young; Hwang, Cheol Yong; Park, Jun Hong; Park, Se Chang

    2006-12-01

    Betanodaviruses are the causative agents of viral nervous necrosis (VNN) in cultured marine fish. A total of 237 apparently healthy aquarium fish, marine (65 species) and freshwater (12 species) fishes and marine invertebrates (4 species), which were stocked in a commercial aquarium in Seoul, South Korea, were collected from November 2005 to February 2006. The brains of the fish and other tissues of the invertebrates were examined by reverse transcriptase-polymerase chain reaction (RT-PCR) and nested PCR to detect betanodavirus. Positive nested PCR results were obtained from the brains of 8 marine fish species (shrimp fish Aeoliscus strigatus, milkfish Chanos chanos, three spot damsel Dascyllus trimaculatus, Japanese anchovy Engraulis japonicus, pinecone fish Monocentris japonica, blue ribbon eel Rhinomuraena quaesita, look down fish Selene vomer, yellow tang Zebrasoma flavesenes), 1 marine invertebrate species (spiny lobster Pamulirus versicolor), and 2 freshwater fish species (South American leaf fish Monocirrhus polyacanthus and red piranha Pygocentrus nattereri). The detection rate in nested PCR was 11/237 (4.64%). These subclinically infected aquarium fish and invertebrates may constitute an inoculum source of betanodaviruses for cultured fishes in the Korean Peninsula. PMID:17106229

  20. Earths Climate Sensitivity: Apparent Inconsistencies in Recent Assessments

    DOE PAGESBeta

    Schwartz, Stephen E.; Charlson, Robert J.; Kahn, Ralph; Rodhe, Henning

    2014-12-08

    Earth's equilibrium climate sensitivity (ECS) and forcing of Earth's climate system over the industrial era have been re-examined in two new assessments: the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC), and a study by Otto et al. (2013). The ranges of these quantities given in these assessments and also in the Fourth (2007) IPCC Assessment are analyzed here within the framework of a planetary energy balance model, taking into account the observed increase in global mean surface temperature over the instrumental record together with best estimates of the rate of increase of planetary heat content.more » This analysis shows systematic differences among the several assessments and apparent inconsistencies within individual assessments. Importantly, the likely range of ECS to doubled CO₂ given in AR5, 1.5–4.5 K/(3.7 W m⁻²) exceeds the range inferred from the assessed likely range of forcing, 1.2–2.9 K/(3.7 W m⁻²), where 3.7 W ⁻² denotes the forcing for doubled CO₂. Such differences underscore the need to identify their causes and reduce the underlying uncertainties. Explanations might involve underestimated negative aerosol forcing, overestimated total forcing, overestimated climate sensitivity, poorly constrained ocean heating, limitations of the energy balance model, or a combination of effects.« less

  1. Deep space laser communications

    NASA Astrophysics Data System (ADS)

    Biswas, Abhijit; Kovalik, Joseph M.; Srinivasan, Meera; Shaw, Matthew; Piazzolla, Sabino; Wright, Malcolm W.; Farr, William H.

    2016-03-01

    A number of laser communication link demonstrations from near Earth distances extending out to lunar ranges have been remarkably successful, demonstrating the augmented channel capacity that is accessible with the use of lasers for communications. The next hurdle on the path to extending laser communication and its benefits throughout the solar system and beyond is to demonstrate deep-space laser communication links. In this paper, concepts and technology development being advanced at the Jet Propulsion Laboratory (JPL) in order to enable deep-space link demonstrations to ranges of approximately 3 AU in the next decade, will be discussed.

  2. Teaching for Deep Learning

    ERIC Educational Resources Information Center

    Smith, Tracy Wilson; Colby, Susan A.

    2007-01-01

    The authors have been engaged in research focused on students' depth of learning as well as teachers' efforts to foster deep learning. Findings from a study examining the teaching practices and student learning outcomes of sixty-four teachers in seventeen different states (Smith et al. 2005) indicated that most of the learning in these classrooms…

  3. The Deep Space Network

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The Deep Space Network (DSN) is the largest and most sensitive scientific telecommunications and radio navigation network in the world. Its principal responsibilities are to support unmanned interplanetary spacecraft missions and to support radio and radar astronomy observations in the exploration of the solar system and the universe. The DSN facilities and capabilities as of January 1988 are described.

  4. The Deep Space Network

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Work accomplished on the Deep Space Network (DSN) was described, including the following topics: supporting research and technology, advanced development and engineering, system implementation, and DSN operations pertaining to mission-independent or multiple-mission development as well as to support of flight projects.

  5. Gene Tree Discordance Causes Apparent Substitution Rate Variation.

    PubMed

    Mendes, Fábio K; Hahn, Matthew W

    2016-07-01

    Substitution rates are known to be variable among genes, chromosomes, species, and lineages due to multifarious biological processes. Here, we consider another source of substitution rate variation due to a technical bias associated with gene tree discordance. Discordance has been found to be rampant in genome-wide data sets, often due to incomplete lineage sorting (ILS). This apparent substitution rate variation is caused when substitutions that occur on discordant gene trees are analyzed in the context of a single, fixed species tree. Such substitutions have to be resolved by proposing multiple substitutions on the species tree, and we therefore refer to this phenomenon as Substitutions Produced by ILS (SPILS). We use simulations to demonstrate that SPILS has a larger effect with increasing levels of ILS, and on trees with larger numbers of taxa. Specific branches of the species trees are consistently, but erroneously, inferred to be longer or shorter, and we show that these branches can be predicted based on discordant tree topologies. Moreover, we observe that fixing a species tree topology when performing tests of positive selection increases the false positive rate, particularly for genes whose discordant topologies are most affected by SPILS. Finally, we use data from multiple Drosophila species to show that SPILS can be detected in nature. Although the effects of SPILS are modest per gene, it has the potential to affect substitution rate variation whenever high levels of ILS are present, particularly in rapid radiations. The problems outlined here have implications for character mapping of any type of trait, and for any biological process that causes discordance. We discuss possible solutions to these problems, and areas in which they are likely to have caused faulty inferences of convergence and accelerated evolution. PMID:26927960

  6. Apparent rotation and jazzing in Leviant's Enigma illusion.

    PubMed

    Hamburger, Kai

    2007-01-01

    In 1981 Leviant devised Enigma, a figure that elicits perceived rotary motion in the absence of real motion. However, despite its striking appearance there is no good explanation for this motion illusion to date. Gregory (1993 Proceedings of the Royal Society of London B 253 123) pointed out a similarity to MacKay's 'complementary' afterimage in his ray pattern and suggested accommodative fluctuations and small eye movements as a potential origin for these phenomena. Furthermore, Zeki et al (1993 Proceedings of the Royal Society of London B 252 215-222) found PET-activation in response to Enigma in visual area V5 and immediately surrounding areas (called V5 complex) suggesting that the illusory motion could be mediated by the same neurons as real motion. In the experiments reported here, I show that the rotary motion is perceived on coloured as well as achromatic annuli intercepting the radial lines. More importantly, the illusory streaming motion continues to be seen with a cycloplegic lens as well as through a pinhole (ie ruling out transient changes of accommodation), and in the positive after-image (ie in the absence of eye movements). Apparent rotation is strongest with radial inducers impinging at right angles onto the annuli, but persist, although to a lesser degree, when the inducing lines are tilted in opposite directions, non-collinear, or replaced by dotted lines or lines with rounded terminators. For an explanation, the Enigma illusion requires a neural mechanism that uses lines abutting an empty annulus to elicit orthogonal streaming motion in one or the other direction. PMID:17718359

  7. The apparent charge of nanoparticles trapped at a water interface.

    PubMed

    Bossa, Guilherme Volpe; Roth, Joseph; Bohinc, Klemen; May, Sylvio

    2016-05-14

    Charged spherical nanoparticles trapped at the interface between water and air or water and oil exhibit repulsive electrostatic forces that contain a long-ranged dipolar and a short-ranged exponentially decaying component. The former are induced by the unscreened electrostatic field through the non-polar low-permittivity medium, and the latter result from the overlap of the diffuse ion clouds that form in the aqueous phase close to the nanoparticles. The magnitude of the long-ranged dipolar interaction is largely determined by the residual charges that remain attached to the air- (or oil-) exposed region of the nanoparticle. In the present work we address the question to what extent the charges on the water-immersed part of the nanoparticle provide an additional contribution to the dipolar interaction. To this end, we model the electrostatic properties of a spherical particle - a nanoparticle or a colloid - that partitions equatorially to the air-water interface, thereby employing nonlinear Poisson-Boltzmann theory in the aqueous solution and accounting for the propagation of the electric field through the interior of the particle. We demonstrate that the apparent charge density on the air-exposed region of the particle, which determines the dipole potential, is influenced by the electrostatic properties in the aqueous solution. We also show that this electrostatic coupling through the particle can be reproduced qualitatively by a simple analytic planar capacitor model. Our results help to rationalize the experimentally observed weak but non-vanishing salt dependence of the forces that stabilize ordered two-dimensional arrays of interface-trapped nanoparticles or colloids. PMID:27049110

  8. Infantile Apparent Life-Threatening Events, an Educational Review

    PubMed Central

    Aminiahidashti, Hamed

    2015-01-01

    Many physicians have received a frantic call from anxious parents stating that their child had stopped breathing, become limp, or turned blue but then had recovered quickly. An apparent life-threatening event (ALTE) is defined as “an episode that is frightening to the observer, and is characterized by some combination of apnea, color change, marked change in muscle tone, choking, gagging, or coughing”. The incidence of ALTE is reported to be 0.05% to 6%. The knowledge about the most common causes and factors associated with higher risk of ALTE could be resulted in a more purposeful approach, improving the decision making process, and benefiting both children and parents. The aim of this review article was to report the epidemiology, etiology, evaluation, management, and disposition of ALTE. Infants with an ALTE might present no signs of acute illness and are commonly managed in the emergency settings that often require significant medical attention; hence, the emergency medicine personnel should be aware of the its clinical importance. There is no specific treatment for ALTE; therefore, the clinical evaluations should be focused on the detection of the underlying causes, which will define the outcomes and prognosis. ALTE is a confusing entity, representing a constellation of descriptive symptoms and signs; in other words, it is not a diagnosis. There are multiple possible etiologies and difficulties in evaluating and managing infants with these events, which are challenges to primary care physicians, emergency medicine specialists, and subspecialty pediatricians. The evaluation of these events in infants includes a detailed history, appropriate physical examination, diagnostic tests guided by obtained clues from the history and physical examination, and observation in the emergency department. PMID:26512363

  9. A possible 20th-century slowdown of southern ocean deep water formation

    PubMed

    Broecker; Sutherland; Peng

    1999-11-01

    Chlorofluorocarbon-11 inventories for the deep Southern Ocean appear to confirm physical oceanographic and geochemical studies in the Southern Ocean, which suggest that no more than 5 x 10(6) cubic meters per second of ventilated deep water is currently being produced. This result conflicts with conclusions based on the distributions of the carbon-14/carbon ratio and a quasi-conservative property, PO(4)(*), in the deep sea, which seem to require an average of about 15 x 10(6) cubic meters per second of Southern Ocean deep ventilation over about the past 800 years. A major reduction in Southern Ocean deep water production during the 20th century (from high rates during the Little Ice Age) may explain this apparent discordance. If this is true, a seesawing of deep water production between the northern Atlantic and Southern oceans may lie at the heart of the 1500-year ice-rafting cycle. PMID:10550046

  10. Hymenoscyphus fraxineus vs. Hymenoscyphus albidus – A comparative light microscopic study on the causal agent of European ash dieback and related foliicolous, stroma-forming species

    PubMed Central

    Baral, Hans-Otto; Bemmann, Martin

    2014-01-01

    Five species of Hymenoscyphus that fruit on black stromatized parts of dead leaves of deciduous trees are presented, giving details on their morphological and ecological characteristics. Several of these species have previously been misplaced in rutstroemiaceous genera because of the presence of a substratal stroma. However, the heteropolar, scutuloid ascospores with an often hook-like lateral protrusion at the rounded apex and the ascus apical ring of the Hymenoscyphus-type represent two reliable morphological characteristics that, together with molecular data, provide clear evidence for their placement in the genus Hymenoscyphus (Helotiaceae). Among the species treated is Hymenoscyphus fraxineus (=Hymenoscyphus pseudoalbidus), the causal agent of the European ash dieback disease. Since 1992 this species started within Europe to replace the rather uncommon Hymenoscyphus albidus, which is likewise confined to leaves of Fraxinus. Hy. fraxineus has been recorded already since 1990 in Eastern Asia (Japan, Korea, northeast of China), where it had been initially misidentified as Lambertella albida (≡Hy. albidus). In these regions, it occurs as a harmless saprotroph on Fraxinus mandshurica and Fraxinus rhynchophylla, suggesting that those populations are native while the European ash dieback disease has a recent Eastern Asiatic origin. The distinctly higher genetic diversity found in Japanese Hy. fraxineus in contrast to European Hy. fraxineus supports this view. Genetic similarities between Japanese Hy. fraxineus and European Hy. albidus suggest that also Hy. albidus might be a descendant of Asian Hy. fraxineus, though having invaded Europe much earlier. However, consistent genetic deviation between European and Asian Hy. fraxineus at two nucleotide positions of the ITS region indicates that the European ash disease originates from a region different from the presently known areas in Eastern Asia. Our results underline the importance of detailed morphological studies

  11. A model of the vertical apparent mass and the fore-and-aft cross-axis apparent mass of the human body during vertical whole-body vibration

    NASA Astrophysics Data System (ADS)

    Nawayseh, Naser; Griffin, Michael J.

    2009-01-01

    The apparent mass of the human body reflects gross movements caused by whole-body vibration and can be used to predict the influence of body dynamics on seat transmissibility. With vertical excitation, various models fit the measured vertical apparent mass of the human body, but experiments also show high fore-and-aft forces on the seat (the fore-and-aft cross-axis apparent mass) that have not influenced current models. This paper defines a model that predicts the vertical apparent mass and the fore-and-aft cross-axis apparent mass of the seated human body during vertical excitation. A three degree-of-freedom model with vertical, fore-and-aft and rotational (i.e. pitch) degrees of freedom has been developed with twelve model parameters (representing inertia, stiffness, damping, and geometry) optimised to the measured vertical apparent mass and the measured fore-and-aft cross-axis apparent mass of the body. The model provides close fits to the moduli and phases for both median data and the responses of 12 individual subjects. The optimum model parameters found by fitting to the median apparent mass of 12 subjects were similar to the medians of the same parameters found by fitting to the individual apparent masses of the same 12 subjects. The model suggests the seated human body undergoes fore-and-aft motion on a seat when exposed to vertical excitation, with the primary resonance frequency of the apparent mass arising from vertical motion of the body. According to the model, changes in the vertical, fore-and-aft, or rotational degree of freedom have an effect on the resonance in the fore-and-aft cross-axis apparent mass.

  12. Infrared microspectroscopy identifies biomolecular changes associated with chronic oxidative stress in mammary epithelium and stroma of breast tissues from healthy young women

    PubMed Central

    Patel, Imran I; Shearer, Debra A; Fogarty, Simon W; Fullwood, Nigel J; Quaroni, Luca; Martin, Francis L; Weisz, Judith

    2014-01-01

    Studies of the decades-long latent stages of breast carcinogenesis have been limited to when hyperplastic lesions are already present. Investigations of earlier stages of breast cancer (BC) latency have been stymied by the lack of fiducial biomarkers needed to identify where in histologically normal tissues progression toward a BC might be taking place. Recent evidence suggests that a marker of chronic oxidative stress (OxS), protein adducts of 4-hydroxy-2-nonenal (4HNE), can meet this need. Specifically: (1) 4HNE immunopositive (4HNE+) mammary epithelial (ME) cells were found to be prevalent in normal (reduction mammoplasty) tissues of most women (including many teenagers) studied, representative of those living in the United States’ high risk-posing environment and: (2) marked (>1.5-fold) differences were identified between tissues of healthy young women with many vs. few 4HNE+ ME cells in the relative levels of transcripts for 42 of the 84 OxS-associated genes represented in SABioscience Oxidative-Stress/Oxidative-Defense PCR array. Herein we used synchrotron radiation-based Fourier-transform infrared (SR-FTIR) microspectroscopy to identify molecular changes associated with 4HNE adducts in basal and luminal ME cells in terminal ductal units (TDLU), which are the cells of origin of BC, and associated intralobular and interlobular stroma, known contributors to carcinogenesis. Multivariate analysis-derived wavenumbers differentiated 4HNE+ and 4HNE− cells in each of the anatomical compartments. Specifically, principal component and linear discriminant analyses of mid-infrared spectra obtained from these cells revealed unambiguous, statistically highly significant differences in the “biochemical fingerprint” of 4HNE+ vs. 4HNE− luminal and basal ME cells, as well as between associated intralobular and interlobular stroma. These findings demonstrate further SR-FTIR microspectroscopy’s ability to identify molecular changes associated with altered

  13. Capacity of Lung Stroma to Educate Dendritic Cells Inhibiting Mycobacteria-Specific T-Cell Response Depends upon Genetic Susceptibility to Tuberculosis

    PubMed Central

    Majorov, Konstantin B.; Logunova, Nadezhda N.; Apt, Alexander S.

    2013-01-01

    The balance between activation and inhibition of local immune responses in affected tissues during prolonged chronic infections is important for host protection. There is ample evidence that regulatory, tolerogenic dendritic cells (DC) are developed and present in tissues and inhibit overwhelming inflammatory reactions. Also, it was firmly established that stromal microenvironment of many organs is able to induce development of immature regulatory DC (DCreg), an essential element of a general immune regulatory network. However, direct experimental data demonstrating inhibition of immune responses by stroma-instructed immature DCreg in infectious models are scarce, and virtually nothing is known about functioning of this axis of immunity during tuberculosis (TB) infection. In this study, we demonstrate that lung stromal cells are capable of supporting the development in culture of immature CD11b+CD11clowCD103- DCreg from lineage-negative (lin-) bone marrow precursors. DCreg developed on lung stroma isolated from mice of genetically TB-hyper-susceptible I/St and relatively resistant B6 inbred strains inhibited proliferative response of mycobacteria-specific CD4+ T-cell lines a dose-dependent manner. Importantly, the inhibitory activity of B6 DCreg was substantially higher than that of I/St Dcreg. Moreover, when the donors of stromal cells were chronically infected with virulent mycobacteria, the capacity to instruct inhibitory DCreg was retained in B6, but further diminished in I/St stromal cells. DCreg-provided suppression was mediated by a few soluble mediators, including PGE2, NO and IL-10. The content of CD4+Foxp3+ Treg cells in the mediastinal, lung-draining lymph nodes at the advanced stages of chronic infection did not change in I/St, but increased 2-fold in B6 mice, and lung pathology was much more pronounced in the former mice. Taken together, these data provide genetic evidence that the capacity to maintain populations of regulatory cells during M

  14. Spatial interpolation of soil organic carbon using apparent electrical conductivity as secondary information

    NASA Astrophysics Data System (ADS)

    Martinez, G.; Vanderlinden, K.; Ordóñez, R.; Muriel, J. L.

    2009-04-01

    Soil organic carbon (SOC) spatial characterization is necessary to evaluate under what circumstances soil acts as a source or sink of carbon dioxide. However, at the field or catchment scale it is hard to accurately characterize its spatial distribution since large numbers of soil samples are necessary. As an alternative, near-surface geophysical sensor-based information can improve the spatial estimation of soil properties at these scales. Electromagnetic induction (EMI) sensors provide non-invasive and non-destructive measurements of the soil apparent electrical conductivity (ECa), which depends under non-saline conditions on clay content, water content or SOC, among other properties that determine the electromagnetic behavior of the soil. This study deals with the possible use of ECa-derived maps to improve SOC spatial estimation by Simple Kriging with varying local means (SKlm). Field work was carried out in a vertisol in SW Spain. The field is part of a long-term tillage experiment set up in 1982 with three replicates of conventional tillage (CT) and Direct Drilling (DD) plots with unitary dimensions of 15x65m. Shallow and deep (up to 0.8m depth) apparent electrical conductivity (ECas and ECad, respectively) was measured using the EM38-DD EMI sensor. Soil samples were taken from the upper horizont and analyzed for their SOC content. Correlation coefficients of ECas and ECad with SOC were low (0.331 and 0.175) due to the small range of SOC values and possibly also to the different support of the ECa and SOC data. Especially the ECas values were higher in the DD plots. The normalized ECa difference (ΔECa), calculated as the difference between the normalized ECas and ECad values, distinguished clearly the CT and DD plots, with the DD plots showing positive ΔECa values and CT plots ΔECa negative values. The field was stratified using fuzzy k-means (FKM) classification of ΔECa (FKM1), and ECas and ECad (FKM2). The FKM1 map mainly showed the difference between

  15. The diagnostic value of biexponential apparent diffusion coefficients in myopathy.

    PubMed

    Ran, Jun; Liu, Yao; Sun, Dong; Morelli, John; Zhang, Ping; Wu, Gang; Sheng, Yuda; Xie, Ruyi; Zhang, Xiaoli; Li, Xiaoming

    2016-07-01

    To investigate the performance of a biexponential signal decay model using DWI in myopathies and to differentiate Polymyositis (PM)/Dermatomyositis (DM), Glycogen Storage Diseases (GSDs) and Muscular Dystrophies (MDs) utilizing diffusion-weighted imaging. 11 healthy volunteers (control group) and 46 patients with myopathy were enrolled in the retrospective study. 27 of 46 patients had PM/DM, 7 patients GSDs and 12 patients MDs. After conventional MR sequences, diffusion weighted imaging with a b-factor ranging from 0 to 1200 s/mm(2) was performed on both thighs. The intra-muscular signal-to-noise ratios (SNRs) on multiple-b DWI images were measured for 7 different muscles and compared among the different groups. The median T2 signal intensity and biexponential apparent diffusion coefficients (ADC), including standard ADC, fast ADC, and slow ADC values, were compared among the different groups. The intra-muscular SNRs were statistically significantly different depending on the b value, and also found among the 4 groups (p < 0.05). The median T2 signal intensity of the normal muscles in control group was statistically significantly lower than that of edematous muscles in the PM/DM, GSDs and MDs groups (p = 0.000), while there were no statistically significant differences among the PM/DM, GSDs, and MDs groups (p > 0.05). The median standard ADC value of the edematous muscles in GSDs was statistically significantly lower than that of normal muscles in the control group (p = 0.000) and the median ADC value of the edematous muscles in PM/DM patients was statistically significantly greater than that of the GSDs (p = 0.000) and MDs groups (p = 0.005). The median slow ADC value of the edematous muscles in MDs patients and PM/DM patients was statistically significantly greater than that of GSDs patients (p < 0.05). Intra-muscular SNR decay curves and biexponential ADC parameters are useful in distinguishing among PM/DM, GSDs, and MDs. PMID:27142711

  16. Apparent water permeability as a physiological parameter in crustaceans

    PubMed

    Rasmussen; Andersen

    1996-01-01

    This article reviews the use of apparent water permeability (AWP) calculated from measurements of isotope-labelled water flux as a physiological estimate of whole-body water permeability in aquatic invertebrates. The rationale and practices of AWP calculations are described in an Appendix. AWP calculations have provided a wealth of information. However, the validity of the method and therefore also of the information obtained have been questioned. Consequently, the use of AWP data in discussions of osmotic and fluid homeostatic questions in aquatic invertebrates is limited. This article reviews three decades of published experiments in which measurements of isotope-labelled water fluxes were used to estimate water permeability in aquatic invertebrates. Data on 24 species of arthropod, most of them decapod crustaceans, are presented. The combined data indicate that the results obtained by different investigators on the same species show good agreement, even though different tracers and experimental methods have been applied. When available, results from other kinds of studies were used to evaluate the results obtained using the AWP measurements. The various results demonstrate that AWP is influenced not only by natural environmental factors, such as salinity and temperature, and by anthropogenic factors, such as potentially toxic trace metals, but that it is also regulated by intrinsic factors, such as ecdysis and life cycle stage. The results obtained can often be explained as effects of components of the habitat of the animal. Accordingly, studies on variations in AWP contribute to our understanding of the different physiological strategies used by species living in a changing environment. We conclude that calculations of AWP offer reliable, relevant physiological data in a range of crustacean species, as long as methodological limitations and uncertainties are kept in mind. In addition, we propose some possible new ways of applying AWP calculations to marine

  17. 45 CFR 73.735-904 - Resolution of apparent or actual conflicts of interest.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 1 2011-10-01 2011-10-01 false Resolution of apparent or actual conflicts of... ADMINISTRATION STANDARDS OF CONDUCT Reporting Financial Interests § 73.735-904 Resolution of apparent or actual... disqualification is employed to resolve an apparent or actual conflict of interest, the disqualified employee...

  18. Living with Deep Vein Thrombosis

    MedlinePlus

    ... page from the NHLBI on Twitter. Living With Deep Vein Thrombosis NHLBI Resources Pulmonary Embolism (Health Topics) Non-NHLBI Resources Deep Vein Thrombosis (MedlinePlus) Pulmonary Embolism (MedlinePlus) Clinical Trials ...

  19. Project DEEP STEAM

    NASA Astrophysics Data System (ADS)

    Aeschliman, D. P.; Clay, R. G.; Donaldson, A. B.; Eisenhawer, S. W.; Fox, R. L.; Johnson, D. R.; Mulac, A. J.

    1982-01-01

    The objective of Project DEEP STEAM is to develop the technology to economically produce heavy oils from deep reservoirs. The tasks included in this project are the development of thermally efficient delivery systems and downhole steam generation systems. During the period January 1-March 31, 1981, effort has continued on a low pressure combustion downhole generator (Rocketdyne), and on two high pressure designs (Foster-Miller Associates, Sandia National Laboratories). The Sandia design was prepared for deployment in the Wilmington Field at Long Beach, California. Progress continued on the Min-Stress II packer concept at L'Garde, Inc., and on the extruded metal packer at Foster-Miller. Initial bare string field data are reported on the insulated tubular test at Lloydminster, Saskatchewan, Canada.

  20. Deep gluteal syndrome

    PubMed Central

    Martin, Hal David; Reddy, Manoj; Gómez-Hoyos, Juan

    2015-01-01

    Deep gluteal syndrome describes the presence of pain in the buttock caused from non-discogenic and extrapelvic entrapment of the sciatic nerve. Several structures can be involved in sciatic nerve entrapment within the gluteal space. A comprehensive history and physical examination can orientate the specific site where the sciatic nerve is entrapped, as well as several radiological signs that support the suspected diagnosis. Failure to identify the cause of pain in a timely manner can increase pain perception, and affect mental control, patient hope and consequently quality of life. This review presents a comprehensive approach to the patient with deep gluteal syndrome in order to improve the understanding of posterior hip anatomy, nerve kinematics, clinical manifestations, imaging findings, differential diagnosis and treatment considerations. PMID:27011826

  1. Deep depth undex simulator

    SciTech Connect

    Higginbotham, R. R.; Malakhoff, A.

    1985-01-29

    A deep depth underwater simulator is illustrated for determining the dual effects of nuclear type underwater explosion shockwaves and hydrostatic pressures on a test vessel while simulating, hydrostatically, that the test vessel is located at deep depths. The test vessel is positioned within a specially designed pressure vessel followed by pressurizing a fluid contained between the test and pressure vessels. The pressure vessel, with the test vessel suspended therein, is then placed in a body of water at a relatively shallow depth, and an explosive charge is detonated at a predetermined distance from the pressure vessel. The resulting shockwave is transmitted through the pressure vessel wall so that the shockwave impinging on the test vessel is representative of nuclear type explosive shockwaves transmitted to an underwater structure at great depths.

  2. Canberra Deep Dish Communications Complex

    NASA Technical Reports Server (NTRS)

    1990-01-01

    View of Canberra 70m (230 ft.) antenna with flags from the three Deep Space Network sites. The Canberra Deep Space Communications Complex, located outside Canberra, Australia, is one of the three complexes which comprise NASA's Deep Space Network. The other complexes are located in Goldstone, California, and Madrid, Spain.

  3. Deep-Sarsa

    NASA Astrophysics Data System (ADS)

    Andrecut, M.; Ali, M. K.

    In this paper we discuss the application of reinforcement learning algorithms to the problem of autonomous robot navigation. We show that the autonomous navigation using the standard delayed reinforcement learning algorithms is an ill posed problem and we present a more efficient algorithm for which the convergence speed is greatly improved. The proposed algorithm (Deep-Sarsa) is based on a combination between the Depth-First Search (a graph searching algorithm) and Sarsa (a delayed reinforcement learning algorithm).

  4. Understanding deep convolutional networks.

    PubMed

    Mallat, Stéphane

    2016-04-13

    Deep convolutional networks provide state-of-the-art classifications and regressions results over many high-dimensional problems. We review their architecture, which scatters data with a cascade of linear filter weights and nonlinearities. A mathematical framework is introduced to analyse their properties. Computations of invariants involve multiscale contractions with wavelets, the linearization of hierarchical symmetries and sparse separations. Applications are discussed. PMID:26953183

  5. Project DEEP STEAM

    NASA Astrophysics Data System (ADS)

    Marshall, B. W.

    Development of technology for thermally efficient downhole delivery of surface generated steam and for downhole steam generators are the major elements of Project DEEP STEAM. Specific activities include development of advanced concept thermal packers, evaluation of the thermal performance of insulated tubing designs in a test tower and in a field environment, and development of downhole steam generator concepts. Field tests were performed in both technology areas and the results and status are presented.

  6. Project DEEP STEAM

    SciTech Connect

    Marshall, B.W.

    1982-01-01

    Development of technology for thermally efficient downhole delivery of surface-generated steam and for downhole steam generators are the major elements of Project DEEP STEAM. Specific activities include development of advanced concept thermal packers, evaluation of the thermal performance of insulated tubing designs in a test tower and in a field environment, and development of downhole steam generator concepts. Field tests have been performed in both technology areas and the results and status are presented.

  7. Stroma-Derived Connective Tissue Growth Factor Maintains Cell Cycle Progression and Repopulation Activity of Hematopoietic Stem Cells In Vitro

    PubMed Central

    Istvánffy, Rouzanna; Vilne, Baiba; Schreck, Christina; Ruf, Franziska; Pagel, Charlotta; Grziwok, Sandra; Henkel, Lynette; Prazeres da Costa, Olivia; Berndt, Johannes; Stümpflen, Volker; Götze, Katharina S.; Schiemann, Matthias; Peschel, Christian; Mewes, Hans-Werner; Oostendorp, Robert A.J.

    2015-01-01

    Summary Hematopoietic stem cells (HSCs) are preserved in co-cultures with UG26-1B6 stromal cells or their conditioned medium. We performed a genome-wide study of gene expression changes of UG26-1B6 stromal cells in contact with Lineage− SCA-1+ KIT+ (LSK) cells. This analysis identified connective tissue growth factor (CTGF) to be upregulated in response to LSK cells. We found that co-culture of HSCs on CTGF knockdown stroma (shCtgf) shows impaired engraftment and long-term quality. Further experiments demonstrated that CD34− CD48− CD150+ LSK (CD34− SLAM) cell numbers from shCtgf co-cultures increase in G0 and senescence and show delayed time to first cell division. To understand this observation, a CTGF signaling network model was assembled, which was experimentally validated. In co-culture experiments of CD34− SLAM cells with shCtgf stromal cells, we found that SMAD2/3-dependent signaling was activated, with increasing p27Kip1 expression and downregulating cyclin D1. Our data support the view that LSK cells modulate gene expression in the niche to maintain repopulating HSC activity. PMID:26527384

  8. Constitutive activation of Beta-catenin in uterine stroma and smooth muscle leads to the development of mesenchymal tumors in mice.

    PubMed

    Tanwar, Pradeep S; Lee, Ho-Joon; Zhang, LiHua; Zukerberg, Lawrence R; Taketo, Makoto M; Rueda, Bo R; Teixeira, Jose M

    2009-09-01

    Leiomyomas and other mesenchymally derived tumors are the most common neoplasms of the female reproductive tract. Presently, very little is known about the etiology and progression of these tumors, which are the primary indication for hysterectomies. Dysregulated WNT signaling through beta-catenin is a well-established mechanism for tumorigenesis. We have developed a mouse model that expresses constitutively activated beta-catenin in uterine mesenchyme driven by the expression of Cre recombinase knocked into the Müllerian-inhibiting substance type II receptor promoter locus to investigate its effects on uterine endometrial stroma and myometrium. These mice show myometrial hyperplasia and develop mesenchymal tumors with 100% penetrance that exhibit histological and molecular characteristics of human leiomyomas and endometrial stromal sarcomas. By immunohistochemistry, we also show that both transforming growth factor beta and the mammalian target of rapamycin are induced by constitutive activation of beta-catenin. The prevalence of the tumors was greater in multiparous mice, suggesting that their development may be a hormonally driven process or that changes in uterine morphology during pregnancy and after parturition induce injury and repair mechanisms that stimulate tumorigenesis from stem/progenitor cells, which normally do not express constitutively activated beta-catenin. Additionally, adenomyosis and endometrial gland hyperplasia were occasionally observed in some mice. These results show evidence suggesting that dysregulated, stromal, and myometrial WNT/beta-catenin signaling has pleiotropic effects on uterine function and tumorigenesis. PMID:19403928

  9. Constitutive Activation of Beta-Catenin in Uterine Stroma and Smooth Muscle Leads to the Development of Mesenchymal Tumors in Mice1

    PubMed Central

    Tanwar, Pradeep S.; Lee, Ho-Joon; Zhang, LiHua; Zukerberg, Lawrence R.; Taketo, Makoto M.; Rueda, Bo R.; Teixeira, Jose M.

    2009-01-01

    Leiomyomas and other mesenchymally derived tumors are the most common neoplasms of the female reproductive tract. Presently, very little is known about the etiology and progression of these tumors, which are the primary indication for hysterectomies. Dysregulated WNT signaling through beta-catenin is a well-established mechanism for tumorigenesis. We have developed a mouse model that expresses constitutively activated beta-catenin in uterine mesenchyme driven by the expression of Cre recombinase knocked into the Müllerian-inhibiting substance type II receptor promoter locus to investigate its effects on uterine endometrial stroma and myometrium. These mice show myometrial hyperplasia and develop mesenchymal tumors with 100% penetrance that exhibit histological and molecular characteristics of human leiomyomas and endometrial stromal sarcomas. By immunohistochemistry, we also show that both transforming growth factor beta and the mammalian target of rapamycin are induced by constitutive activation of beta-catenin. The prevalence of the tumors was greater in multiparous mice, suggesting that their development may be a hormonally driven process or that changes in uterine morphology during pregnancy and after parturition induce injury and repair mechanisms that stimulate tumorigenesis from stem/progenitor cells, which normally do not express constitutively activated beta-catenin. Additionally, adenomyosis and endometrial gland hyperplasia were occasionally observed in some mice. These results show evidence suggesting that dysregulated, stromal, and myometrial WNT/beta-catenin signaling has pleiotropic effects on uterine function and tumorigenesis. PMID:19403928

  10. Mechanoregulatory tumor-stroma crosstalk in pancreatic cancer: Measurements of the effects of extracellular matrix mechanics on tumor growth behavior, and vice-versa, to inform therapeutics

    NASA Astrophysics Data System (ADS)

    Celli, Jonathan; Jones, Dustin; El-Hamidi, Hamid; Cramer, Gwendolyn; Hanna, William; Caide, Andrew; Jafari, Seyedehrojin

    The rheological properties of the extracellular matrix (ECM) have been shown to play key roles in regulating tumor growth behavior through mechanotranduction pathways. The role of the mechanical microenvironment may be particularly important tumors of the pancreas, noted for an abundance of rigid fibrotic stroma, implicated in therapeutic resistance. At the same time, cancer cells and their stromal partners (e.g. tumor associated fibroblasts) continually alter the mechanical microenvironment in response to extracellular physical and biochemical cues as part of a two-way mechanoregulatory dialog. Here, we describe experimental studies using 3D pancreatic cell cultures with customized mechanical properties, combined with optical microrheology to provide insight into tumor-driven matrix remodeling. Quantitative microscopy provides measurements of phenotypic changes accompanying systematic variation of ECM composition in collagen and laminin-rich basement membrane admixtures, while analysis of the trajectories of passive tracer particles embedded in ECM report dynamic changes in heterogeneity, microstructure and local shear modulus accompanying both ECM stiffening (fibrosis) processes, and ECM degradation near invading cells. We gratefully acknowledge funding from the National Cancer Institute, R00CA155045 (PI: Celli).

  11. Tissue-specific patterns of gene expression in the epithelium and stroma of normal colon in healthy individuals in an aspirin intervention trial.

    PubMed

    Thomas, Sushma S; Makar, Karen W; Li, Lin; Zheng, Yingye; Yang, Peiying; Levy, Lisa; Rudolph, Rebecca Y; Lampe, Paul D; Yan, Min; Markowitz, Sanford D; Bigler, Jeannette; Lampe, Johanna W; Potter, John D

    2015-12-01

    Regular aspirin use reduces colon adenoma and carcinoma incidence. UDP-glucuronosyltransferases (UGT) are involved in aspirin metabolism and clearance, and variant alleles in UGT1A6 have been shown to alter salicylic acid metabolism and risk of colon neoplasia. In a randomized, cross-over, placebo-controlled trial of 44 healthy men and women, homozygous for UGT1A6*1 or UGT1A6*2, we explored differences between global epithelial and stromal expression, using Affymetrix U133 + 2.0 microarrays and tested effects of 60-day aspirin supplementation (325 mg/d) on epithelial and stromal gene expression and colon prostaglandin E2 (PGE2) levels. We conducted a comprehensive study of differential gene expression between normal human colonic epithelium and stroma from healthy individuals. Although no statistically significant differences in gene expression were observed in response to aspirin or UGT1A6 genotype, we have identified the genes uniquely and reproducibly expressed in each tissue type and have analyzed the biologic processes they represent. Here we describe in detail how the data, deposited in the Gene Expression Omnibus (GEO) - accession number GSE71571 - was generated including the basic analysis as contained in the manuscript published in BMC Medical Genetics with the PMID 25927723 (Thomas et al., 2015 [9]). PMID:26697360

  12. Apparent diffusion coefficient measurements to support a diagnosis of intracranial hypotension

    PubMed Central

    Fulwadhva, U; Dundmadappa, S K

    2014-01-01

    Objective: Intracranial hypotension (ICH) can be a challenging diagnosis, as cerebrospinal fluid leaks may be difficult to confirm, patients may have other causes for clinical symptoms and imaging findings can be non-specific, particularly in the setting of comorbidities. We investigate the use of brain diffusion measurements [apparent diffusion coefficient (ADC) values] in the assessment of ICH. Methods: 13 cases of ICH were identified retrospectively based on imaging findings and their clinical histories were compared with 13 control subjects. Regional ADC values and average diffusion constant (Dav) from brain slice ADC histograms were measured. Results: ADC values trended higher in all brain regions in patients with ICH than those in control subjects, with statistically significant differences in frontal white matter, mid-brain and deep grey structures. Dav determined by a single-slice ADC histogram was significantly higher in patients with ICH than in the control group (p = 0.008). In two cases followed longitudinally, Dav correlated with the patient's symptoms and decreased towards normal value with blood patch. In one case, decreased Dav correlated with the formation of subdural collections. Conclusion: Cerebral oedema as assessed by increased ADC is strongly correlated with ICH (10 of 13 cases). Histographic analysis of ADC values may offer increased accuracy of ADC measurement. ADC value assessment in the determination of ICH may be particularly useful in complex clinical cases, where treatment is followed over time or where gadolinium is not used and meningeal enhancement cannot be assessed. Advances in knowledge: This article investigates the use of brain diffusion measurements in the assessment of ICH in the clinical setting. PMID:24896198

  13. The biodiversity of the deep Southern Ocean benthos

    PubMed Central

    Brandt, A; De Broyer, C; De Mesel, I; Ellingsen, K.E; Gooday, A.J; Hilbig, B; Linse, K; Thomson, M.R.A; Tyler, P.A

    2006-01-01

    Our knowledge of the biodiversity of the Southern Ocean (SO) deep benthos is scarce. In this review, we describe the general biodiversity patterns of meio-, macro- and megafaunal taxa, based on historical and recent expeditions, and against the background of the geological events and phylogenetic relationships that have influenced the biodiversity and evolution of the investigated taxa. The relationship of the fauna to environmental parameters, such as water depth, sediment type, food availability and carbonate solubility, as well as species interrelationships, probably have shaped present-day biodiversity patterns as much as evolution. However, different taxa exhibit different large-scale biodiversity and biogeographic patterns. Moreover, there is rarely any clear relationship of biodiversity pattern with depth, latitude or environmental parameters, such as sediment composition or grain size. Similarities and differences between the SO biodiversity and biodiversity of global oceans are outlined. The high percentage (often more than 90%) of new species in almost all taxa, as well as the high degree of endemism of many groups, may reflect undersampling of the area, and it is likely to decrease as more information is gathered about SO deep-sea biodiversity by future expeditions. Indeed, among certain taxa such as the Foraminifera, close links at the species level are already apparent between deep Weddell Sea faunas and those from similar depths in the North Atlantic and Arctic. With regard to the vertical zonation from the shelf edge into deep water, biodiversity patterns among some taxa in the SO might differ from those in other deep-sea areas, due to the deep Antarctic shelf and the evolution of eurybathy in many species, as well as to deep-water production that can fuel the SO deep sea with freshly produced organic matter derived not only from phytoplankton, but also from ice algae. PMID:17405207

  14. Imagining Deep Time (Invited)

    NASA Astrophysics Data System (ADS)

    Talasek, J.

    2013-12-01

    Imagining Deep Time '...the mind seemed to grow giddy by looking so far into the abyss of time.' John Playfair (1748 -1819), scientist and mathematician "Man cannot afford to conceive of nature and exclude himself." Emmit Gowin, photographer 'A person would have to take themselves out of the human context to begin to think in terms of geologic time. They would have to think like a rock.' Terry Falke, photographer The term Deep Time refers to the vastness of the geological time scale. First conceived in the 18th century, the development of this perspective on time has been pieced together like a jigsaw puzzle of information and observations drawn from the study of the earth's structure and discovered fossilized flora and fauna. Deep time may possibly be the greatest contribution made by the discipline of geology forever impacting our perception of earth and our relationship to it. How do we grasp such vast concepts as deep time which relates to the origins of the earth or cosmic time which relates to the origins of the universe - concepts that exist far beyond the realm of human experience? Further more how do we communicate this? The ability to visualize is a powerful tool of discovery and communication for the scientist and it is part and parcel of the work of visual artists. The scientific process provides evidence yet it is imagination on the part of the scientists and artists alike that is needed to interpret that information. This exhibition represents an area where both rational and intuitive thinking come together to explore this question of how we relate to the vastness of time. The answer suggested by the combination of art work assembled here suggests that we do so through a combination of visual metaphors (cycles, circles, arrows, trajectories) and visual evidence (rock formations, strata, fossils of fauna and flora) while being mediated through various technologies. One provides factual and empirical evidence while the other provides a way of grasping

  15. The state of the photosynthetic apparatus in leaves as analyzed by rapid gas exchange and optical methods: the pH of the chloroplast stroma and activation of enzymes in vivo.

    PubMed

    Laisk, A; Oja, V; Kiirats, O; Raschke, K; Heber, U

    1989-03-01

    The exchange of CO2 and O2 was measured in leaves using specially constructed equipment capable of responding to rapid transients. Optical measurements provided information on cytochrome f and P 700 oxidation in the light. The following results were obtained: i) The solubilization of CO2 was used to calculate the pH of the chloroplast stroma in darkened leaves. Values ranged from pH 7.8 to pH 8.0 in different C3 plants. ii) Illumination of predarkened leaves of Helianthus annuus L. resulted in three distinct phases of O2 evolution that illustrate the complexity of light activation of the photosynthetic apparatus. A first burst of O2 is attributed to the reduction of electron carriers of the electron-transport chain. While plastoquinone was reduced, cytochrome f was oxidized. Appreciable oxidation of P 700 became possible only during the second O2 burst, which indicates the reduction of the phosphoglycerate pool. Extensive oxidation required the opening of an electron gate on the reducing side of photosystem I. The subsequent slow rise in O2 evolution towards a steady state reflects activation of the Calvin cycle and is the result of CO2 assimilation. iii) Light-dependent CO2 uptake by predarkened leaves occurred in four phases, three of them based on pH changes in the chloroplast stroma. Initial CO2 uptake was small and probably caused by protonation of reduced plastoquinone. In the second phase, which coincided with the reduction of the pool of phosphoglycerate, the initial alkalization of the chloroplast stroma was substantially increased. In the third phase, the stroma alkalization decreased, and the fourth phase was dominated by CO2 assimilation. iv) Respiratory CO2 production was partially suppressed in the light during the second phase of O2 evolution while phosphoglycerate was being reduced. PMID:24212428

  16. Bone marrow stroma-induced resistance of chronic lymphocytic leukemia cells to arsenic trioxide involves Mcl-1 upregulation and is overcome by inhibiting the PI3Kδ or PKCβ signaling pathways.

    PubMed

    Amigo-Jiménez, Irene; Bailón, Elvira; Aguilera-Montilla, Noemí; Terol, María José; García-Marco, José A; García-Pardo, Angeles

    2015-12-29

    CLL remains an incurable disease in spite of the many new compounds being studied. Arsenic trioxide (ATO) induces apoptosis in all CLL cell types and could constitute an efficient therapy. To further explore this, we have studied the influence of stromal cells, key components of the CLL microenvironment, on the response of CLL cells to ATO. Bone marrow stromal cells induced CLL cell resistance to 2 μM ATO and led to activation of Lyn, ERK, PI3K and PKC, as well as NF-κB and STAT3. Mcl-1, Bcl-xL, and Bfl-1 were also upregulated after the co-culture. Inhibition experiments indicated that PI3K and PKC were involved in the resistance to ATO induced by stroma. Moreover, idelalisib and sotrastaurin, specific inhibitors for PI3Kδ and PKCβ, respectively, inhibited Akt phosphorylation, NF-κB/STAT3 activation and Mcl-1 upregulation, and rendered cells sensitive to ATO. Mcl-1 was central to the mechanism of resistance to ATO, since: 1) Mcl-1 levels correlated with the CLL cell response to ATO, and 2) blocking Mcl-1 expression or function with specific siRNAs or inhibitors overcame the protecting effect of stroma. We have therefore identified the mechanism involved in the CLL cell resistance to ATO induced by bone marrow stroma and show that idelalisib or sotrastaurin block this mechanism and restore sensibility to ATO. Combination of ATO with these inhibitors may thus constitute an efficient treatment for CLL. PMID:26540567

  17. Bone marrow stroma-induced resistance of chronic lymphocytic leukemia cells to arsenic trioxide involves Mcl-1 upregulation and is overcome by inhibiting the PI3Kδ or PKCβ signaling pathways

    PubMed Central

    Amigo-Jiménez, Irene; Bailón, Elvira; Aguilera-Montilla, Noemí; Terol, María José; García-Marco, José A.; García-Pardo, Angeles

    2015-01-01

    CLL remains an incurable disease in spite of the many new compounds being studied. Arsenic trioxide (ATO) induces apoptosis in all CLL cell types and could constitute an efficient therapy. To further explore this, we have studied the influence of stromal cells, key components of the CLL microenvironment, on the response of CLL cells to ATO. Bone marrow stromal cells induced CLL cell resistance to 2 μM ATO and led to activation of Lyn, ERK, PI3K and PKC, as well as NF-κB and STAT3. Mcl-1, Bcl-xL, and Bfl-1 were also upregulated after the co-culture. Inhibition experiments indicated that PI3K and PKC were involved in the resistance to ATO induced by stroma. Moreover, idelalisib and sotrastaurin, specific inhibitors for PI3Kδ and PKCβ, respectively, inhibited Akt phosphorylation, NF-κB/STAT3 activation and Mcl-1 upregulation, and rendered cells sensitive to ATO. Mcl-1 was central to the mechanism of resistance to ATO, since: 1) Mcl-1 levels correlated with the CLL cell response to ATO, and 2) blocking Mcl-1 expression or function with specific siRNAs or inhibitors overcame the protecting effect of stroma. We have therefore identified the mechanism involved in the CLL cell resistance to ATO induced by bone marrow stroma and show that idelalisib or sotrastaurin block this mechanism and restore sensibility to ATO. Combination of ATO with these inhibitors may thus constitute an efficient treatment for CLL. PMID:26540567

  18. Image-guided modified deep anterior lamellar keratoplasty (DALK) corneal transplant using intraoperative optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Tao, Yuankai K.; LaBarbera, Michael; Ehlers, Justis P.; Srivastava, Sunil K.; Dupps, William J.

    2015-03-01

    Deep anterior lamellar keratoplasty (DALK) is an alternative to full-thickness corneal transplant and has advantages including the absence of allograft rejection; shortened duration of topical corticosteroid treatment and reduced associated risk of glaucoma, cataract, or infection; and enables use of grafts with poor endothelial quality. DALK begins by performing a trephination of approximately 80% stromal thickness, as measured by pachymetry. After removal of the anterior stoma, a needle is inserted into the residual stroma to inject air or viscoelastic to dissect Descemet's membrane. These procedures are inherently difficult and intraoperative rates of Descemet's membrane perforation between 4-39% have been reported. Optical coherence tomography (OCT) provides high-resolution images of tissue microstructures in the cornea, including Descemet's membrane, and allows quantitation of corneal layer thicknesses. Here, we use crosssectional intraoperative OCT (iOCT) measurements of corneal thickness during surgery and a novel micrometeradjustable biopsy punch to precision-cut the stroma down to Descemet's membrane. Our prototype cutting tool allows us to establish a dissection plane at the corneal endothelium interface, mitigates variability in cut-depths as a result of tremor, reduces procedure complexity, and reduces complication rates. iOCT-guided modified DALK procedures were performed on 47 cadaveric porcine eyes by non-experts and achieved a perforation rate of ~5% with a mean corneal dissection time <18 minutes. The procedure was also successful performed on a human donor eye without perforation. Our data shows the potential for iOCT-guided precision anterior segment surgery without variability as a result of tremor and improvements to standard clinical care.

  19. Pachymetry-guided intrastromal air injection ("pachy-bubble") for deep anterior lamellar keratoplasty.

    PubMed

    Ghanem, Ramon C; Ghanem, Marcielle A

    2012-09-01

    To evaluate an innovative technique for intrastromal air injection to achieve deep anterior lamellar keratoplasty (DALK) with bare Descemet membrane (DM). Thirty-four eyes with anterior corneal pathology, including 27 with keratoconus, underwent DALK. After 400 μm trephination with a suction trephine, ultrasound pachymetry was performed 0.8 mm internally from the trephination groove in the 11 to 1 o'clock position. In this area, a 2-mm incision was created, parallel to the groove, with a micrometer diamond knife calibrated to 90% depth of the thinnest measurement. A cannula was inserted through the incision and 0.5 mL of air was injected to dissect the DM from the stroma. After peripheral paracentesis, anterior keratectomy was carried out to bare the DM. A 0.25-mm oversized graft was sutured in place. Overall, 94.1% of eyes achieved DALK. Bare DM was achieved in 30 eyes, and a pre-DM dissection was performed in 2 eyes. Air injection was successful in detaching the DM (achieving the big bubble) in 88.2% of the eyes. In keratoconus eyes, the rate was 88.9%. All cases but one required a single air injection to achieve DM detachment. Microperforations occurred in 5 cases: 3 during manual layer-by-layer dissection after air injection failed to detach the DM, 1 during removal of the residual stroma after big-bubble formation, and 1 during the diamond knife incision. Two cases (5.9%) were converted to penetrating keratoplasty because of macroperforations. The technique was reproducible, safe, and highly effective in promoting DALK with bare DM. PMID:22367050

  20. Apparent transverse compressive material properties of the digital flexor tendons and the median nerve in the carpal tunnel.

    PubMed

    Main, Erin K; Goetz, Jessica E; Rudert, M James; Goreham-Voss, Curtis M; Brown, Thomas D

    2011-03-15

    Carpal tunnel syndrome is a frequently encountered peripheral nerve disorder caused by mechanical insult to the median nerve, which may in part be a result of impingement by the adjacent digital flexor tendons. Realistic finite element (FE) analysis to determine contact stresses between the flexor tendons and median nerve depends upon the use of physiologically accurate material properties. To assess the transverse compressive properties of the digital flexor tendons and median nerve, these tissues from ten cadaveric forearm specimens were compressed transversely while under axial load. The experimental compression data were used in conjunction with an FE-based optimization routine to determine apparent hyperelastic coefficients (μ and α) for a first-order Ogden material property definition. The mean coefficient pairs were μ=35.3 kPa, α=8.5 for the superficial tendons, μ=39.4 kPa, α=9.2 for the deep tendons, μ=24.9 kPa, α=10.9 for the flexor pollicis longus (FPL) tendon, and μ=12.9 kPa, α=6.5 for the median nerve. These mean Ogden coefficients indicate that the FPL tendon was more compliant at low strains than either the deep or superficial flexor tendons, and that there was no significant difference between superficial and deep flexor tendon compressive behavior. The median nerve was significantly more compliant than any of the flexor tendons. The material properties determined in this study can be used to better understand the functional mechanics of the carpal tunnel soft tissues and possible mechanisms of median nerve compressive insult, which may lead to the onset of carpal tunnel syndrome. PMID:21194695

  1. The nature of thinking, shallow and deep

    PubMed Central

    Brase, Gary L.

    2014-01-01

    Because the criteria for success differ across various domains of life, no single normative standard will ever work for all types of thinking. One method for dealing with this apparent dilemma is to propose that the mind is made up of a large number of specialized modules. This review describes how this multi-modular framework for the mind overcomes several critical conceptual and theoretical challenges to our understanding of human thinking, and hopefully clarifies what are (and are not) some of the implications based on this framework. In particular, an evolutionarily informed “deep rationality” conception of human thinking can guide psychological research out of clusters of ad hoc models which currently occupy some fields. First, the idea of deep rationality helps theoretical frameworks in terms of orienting themselves with regard to time scale references, which can alter the nature of rationality assessments. Second, the functional domains of deep rationality can be hypothesized (non-exhaustively) to include the areas of self-protection, status, affiliation, mate acquisition, mate retention, kin care, and disease avoidance. Thus, although there is no single normative standard of rationality across all of human cognition, there are sensible and objective standards by which we can evaluate multiple, fundamental, domain-specific motives underlying human cognition and behavior. This review concludes with two examples to illustrate the implications of this framework. The first example, decisions about having a child, illustrates how competing models can be understood by realizing that different fundamental motives guiding people’s thinking can sometimes be in conflict. The second example is that of personifications within modern financial markets (e.g., in the form of corporations), which are entities specifically constructed to have just one fundamental motive. This single focus is the source of both the strengths and flaws in how such entities behave. PMID

  2. Deep-sea Hexactinellida (Porifera) of the Weddell Sea

    NASA Astrophysics Data System (ADS)

    Janussen, Dorte; Tabachnick, Konstantin R.; Tendal, Ole S.

    2004-07-01

    New Hexactinellida from the deep Weddel Sea are described. This moderately diverse hexactinellid fauna includes 14 species belonging to 12 genera, of which five species and one subgenus are new to science: Periphragella antarctica n. sp., Holascus pseudostellatus n. sp., Caulophacus (Caulophacus) discohexactinus n. sp., C. ( Caulodiscus) brandti n. sp., C. ( Oxydiscus) weddelli n. sp., and C. ( Oxydiscus) n. subgen. So far, 20 hexactinellid species have been reported from the deep Weddell Sea, 15 are known from the northern part and 10 only from here, while 10 came from the southern area, and five of these only from there. However, this apparent high "endemism" of Antarctic hexactinellid sponges is most likely the result of severe undersampling of the deep-sea fauna. We find no reason to believe that a division between an oceanic and a more continental group of species exists. The current poor database indicates that a substantial part of the deep hexactinellid fauna of the Weddell Sea is shared with other deep-sea regions, but it does not indicate a special biogeographic relationship with any other ocean.

  3. A ubiquitous thermoacidophilic archaeon from deep-sea hydrothermal vents

    USGS Publications Warehouse

    Reysenbach, A.-L.; Liu, Yajing; Banta, A.B.; Beveridge, T.J.; Kirshtein, J.D.; Schouten, S.; Tivey, M.K.; Von Damm, K. L.; Voytek, M.A.

    2006-01-01

    Deep-sea hydrothermal vents are important in global biogeochemical cycles, providing biological oases at the sea floor that are supported by the thermal and chemical flux from the Earth's interior. As hot, acidic and reduced hydrothermal fluids mix with cold, alkaline and oxygenated sea water, minerals precipitate to form porous sulphide-sulphate deposits. These structures provide microhabitats for a diversity of prokaryotes that exploit the geochemical and physical gradients in this dynamic ecosystem. It has been proposed that fluid pH in the actively venting sulphide structures is generally low (pH < 4.5), yet no extreme thermoacidophile has been isolated from vent deposits. Culture-independent surveys based on ribosomal RNA genes from deep-sea hydrothermal deposits have identified a widespread euryarchaeotal lineage, DHVE2 (deep-sea hydrothermal vent euryarchaeotic 2). Despite the ubiquity and apparent deep-sea endemism of DHVE2, cultivation of this group has been unsuccessful and thus its metabolism remains a mystery. Here we report the isolation and cultivation of a member of the DHVE2 group, which is an obligate thermoacidophilic sulphur- or iron-reducing heterotroph capable of growing from pH 3.3 to 5.8 and between 55 and 75??C. In addition, we demonstrate that this isolate constitutes up to 15% of the archaeal population, providing evidence that thermoacidophiles may be key players in the sulphur and iron cycling at deep-sea vents. ?? 2006 Nature Publishing Group.

  4. A ubiquitous thermoacidophilic archaeon from deep-sea hydrothermal vents.

    PubMed

    Reysenbach, Anna-Louise; Liu, Yitai; Banta, Amy B; Beveridge, Terry J; Kirshtein, Julie D; Schouten, Stefan; Tivey, Margaret K; Von Damm, Karen L; Voytek, Mary A

    2006-07-27

    Deep-sea hydrothermal vents are important in global biogeochemical cycles, providing biological oases at the sea floor that are supported by the thermal and chemical flux from the Earth's interior. As hot, acidic and reduced hydrothermal fluids mix with cold, alkaline and oxygenated sea water, minerals precipitate to form porous sulphide-sulphate deposits. These structures provide microhabitats for a diversity of prokaryotes that exploit the geochemical and physical gradients in this dynamic ecosystem. It has been proposed that fluid pH in the actively venting sulphide structures is generally low (pH < 4.5), yet no extreme thermoacidophile has been isolated from vent deposits. Culture-independent surveys based on ribosomal RNA genes from deep-sea hydrothermal deposits have identified a widespread euryarchaeotal lineage, DHVE2 (deep-sea hydrothermal vent euryarchaeotic 2). Despite the ubiquity and apparent deep-sea endemism of DHVE2, cultivation of this group has been unsuccessful and thus its metabolism remains a mystery. Here we report the isolation and cultivation of a member of the DHVE2 group, which is an obligate thermoacidophilic sulphur- or iron-reducing heterotroph capable of growing from pH 3.3 to 5.8 and between 55 and 75 degrees C. In addition, we demonstrate that this isolate constitutes up to 15% of the archaeal population, providing evidence that thermoacidophiles may be key players in the sulphur and iron cycling at deep-sea vents. PMID:16871216

  5. Deep Space Positioning System

    NASA Technical Reports Server (NTRS)

    Vaughan, Andrew T. (Inventor); Riedel, Joseph E. (Inventor)

    2016-01-01

    A single, compact, lower power deep space positioning system (DPS) configured to determine a location of a spacecraft anywhere in the solar system, and provide state information relative to Earth, Sun, or any remote object. For example, the DPS includes a first camera and, possibly, a second camera configured to capture a plurality of navigation images to determine a state of a spacecraft in a solar system. The second camera is located behind, or adjacent to, a secondary reflector of a first camera in a body of a telescope.

  6. Deep shadow occulter

    NASA Technical Reports Server (NTRS)

    Cash, Webster (Inventor)

    2010-01-01

    Methods and apparatus are disclosed for occulting light. The occulter shape suppresses diffraction at any given size or angle and is practical to build because it can be made binary to avoid scatter. Binary structures may be fully opaque or fully transmitting at specific points. The diffraction suppression is spectrally broad so that it may be used with incoherent white light. An occulter may also include substantially opaque inner portion and an at least partially transparent outer portion. Such occulters may be used on the ground to create a deep shadow in a short distance, or may be used in space to suppress starlight and reveal exoplanets.

  7. Mesenchymal stroma cells trigger early attraction of M1 macrophages and endothelial cells into fibrin hydrogels, stimulating long bone healing without long-term engraftment.

    PubMed

    Seebach, Elisabeth; Freischmidt, Holger; Holschbach, Jeannine; Fellenberg, Jörg; Richter, Wiltrud

    2014-11-01

    Implantation of mesenchymal stroma cells (MSCs) is an attractive approach to stimulate closure of large bone defects but an optimal carrier has yet to be defined. MSCs may display trophic and/or immunomodulatory features or stimulate bone healing by their osteogenic activity. The aim of this study was to unravel whether fibrin hydrogel supports early actions of implanted MSCs, such as host cell recruitment, immunomodulation and tissue regeneration, in long bone defects. Female rats received cell-free fibrin or male MSCs embedded in a fibrin carrier into plate-stabilized femoral bone defects. Removed callus was analyzed for host cell invasion (day 6), local cytokine expression (days 3 and 6) and persistence of male MSCs (days 3, 6, 14 and 28). Fibrin-MSC composites triggered fast attraction of host cells into the hydrogel while cell-free fibrin implants were not invaded. A migration front dominated by M1 macrophages and endothelial progenitor cells formed while M2 macrophages remained sparse. Only MSC-seeded fibrin hydrogel stimulated early tissue maturation and primitive vessel formation at day 6 in line with significantly higher VEGF mRNA levels recorded at day 3. Local TNF-α, IL-1β and IL-10 expression indicated a balanced immune cell activity independent of MSC implantation. Implanted MSCs persisted until day 14 but not day 28. Our results demonstrate that fibrin hydrogel is an attractive carrier for MSC implantation into long bone defects, supporting host cell attraction and pro-angiogenic activity. By this angiogenesis, implant integration and tissue maturation was stimulated in long bone healing independent of long-term engraftment of implanted MSCs. PMID:25058402

  8. The assessment of cryopreservation conditions for human umbilical cord stroma-derived mesenchymal stem cells towards a potential use for stem cell banking.

    PubMed

    Balci, Deniz; Can, Alp

    2013-01-01

    Human umbilical cord stroma-derived mesenchymal stem cells (hUCS-MSCs) are considered as a remarkable and promising stem cell source to be potentially used in cellular therapies. While no graft rejection has been reported in the recipient organism even in xeno-transplantation studies, attenuate tumor cell growth and gene transfers have been experimentally shown. In this study, we have demonstrated a reliable, reproducible and efficient cryopreservation method of hUCS-MSCs resulting in one of the highest cell survival rates reported so far. Conventional, computer-controlled multistep slow freezing (MSSF), and vitrification methods were comparatively tested using cell permeable [dimethylsulfoxide (DMSO), ethylene glycol] and impermeable [trehalose, sucrose, hydroxyethyl starch (HES), human serum albumin] cryoprotectant agents (CPAs). After determining the ice nucleation point for each solution, latent heat evolution was suppressed during freezing, followed by a cooling process to -40°C at 1°C/min or 0.3°C/min. The efficiency of the cryopreservation techniques used was determined by cell viability and proliferation assays, the expression of cell surface markers, cytoskeletal proteins and chromosome alignments. The cell survival rate was found to be highest (87 ± 5%) by MSSF with sucrose (0.1 M) +DMSO (10%) at 1°C/min freezing rate. In this group, no significant difference was noted before and after the cryopreservation in cell morphology, cytokeratin, vimentin, and α-smooth muscle actin profiles and the expressions of CD105, CD90, CD73, CD29 and HLA-DR. Second highest cell survival ratio (85 ± 6%) was obtained in DMSO (10%) alone at 1°C/min freezing rate. Interestingly, poor (18 ± 15%) cell survival rates were obtained after vitrification. Cumulatively, results indicated that MSSF favors the other freezing protocols with an addition of sucrose or DMSO alone depending on the freezing rate used. PMID:23270628

  9. Co-Targeting Prostate Cancer Epithelium and Bone Stroma by Human Osteonectin-Promoter-Mediated Suicide Gene Therapy Effectively Inhibits Androgen-Independent Prostate Cancer Growth.

    PubMed

    Sung, Shian-Ying; Chang, Junn-Liang; Chen, Kuan-Chou; Yeh, Shauh-Der; Liu, Yun-Ru; Su, Yen-Hao; Hsueh, Chia-Yen; Chung, Leland W K; Hsieh, Chia-Ling

    2016-01-01

    Stromal-epithelial interaction has been shown to promote local tumor growth and distant metastasis. We sought to create a promising gene therapy approach that co-targets cancer and its supporting stromal cells for combating castration-resistant prostate tumors. Herein, we demonstrated that human osteonectin is overexpressed in the prostate cancer epithelium and tumor stroma in comparison with their normal counterpart. We designed a novel human osteonectin promoter (hON-522E) containing positive transcriptional regulatory elements identified in both the promoter and exon 1 region of the human osteonectin gene. In vitro reporter assays revealed that the hON-522E promoter is highly active in androgen receptor negative and metastatic prostate cancer and bone stromal cells compared to androgen receptor-positive prostate cancer cells. Moreover, in vivo prostate-tumor-promoting activity of the hON-522E promoter was confirmed by intravenous administration of an adenoviral vector containing the hON-522E promoter-driven luciferase gene (Ad-522E-Luc) into mice bearing orthotopic human prostate tumor xenografts. In addition, an adenoviral vector with the hON-522E-promoter-driven herpes simplex virus thymidine kinase gene (Ad-522E-TK) was highly effective against the growth of androgen-independent human prostate cancer PC3M and bone stromal cell line in vitro and in pre-established PC3M tumors in vivo upon addition of the prodrug ganciclovir. Because of the heterogeneity of human prostate tumors, hON-522E promoter-mediated gene therapy has the potential for the treatment of hormone refractory and bone metastatic prostate cancers. PMID:27054343

  10. Long-lasting morphofunctional remodelling of liver parenchyma and stroma after a single exposure to low and moderate doses of cadmium in rats

    PubMed Central

    Cupertino, Marli C; Costa, Kyvia L C; Santos, Daiane C M; Novaes, Rômulo D; Condessa, Suellen S; Neves, Ana C; Oliveira, Juraci A; Matta, Sérgio L P

    2013-01-01

    Frequent exposure to cadmium (Cd) in low doses is common; however, the long-lasting effects of this exposure are still poorly understood. Therefore in this study we have evaluated long-lasting hepatic morphofunctional adaptations in rats exposed to low and moderate doses of Cd. Five experimental groups were tested: control (0.9% saline) and other four receiving single intraperitoneal doses of 0.67, 0.74, 0.86 and 1.1 mg of Cd/kg. The animals were killed after eight weeks and the following parameters were analysed: biometrics, oedema, Cd bio-accumulation, collagen, glycogen, lipid droplets, superoxide dismutase (SOD) and catalase (CAT), serum transaminases, liver histopathology and stereology. In all groups exposed to Cd there was significant increase in SOD and CAT activities, ALP levels, proportion of binucleated hepatocytes, nuclei/cytoplasm ratio, macrophages (Kupffer cells) and collagen fibres. In these groups, glycogen accumulation by hepatocytes and the proportion of sinusoidal capillaries were significantly reduced compared with controls. The liver somatic index was increased, and liver oedema was evident in animals exposed to higher dose of Cd. Areas of necrosis were found in animals exposed to the three highest doses. These results indicate that Cd is an extremely toxic bioactive heavy metal, which even at low doses is able to disrupt liver homeostasis. At low and moderate doses, Cd exposure induces morphofunctional pathological remodelling of the hepatic stroma and parenchyma, which remain active after eight weeks. In response to injury, the liver tissue triggers a reactive process by enhancing activation of antioxidant enzymes and collagenogenesis. PMID:24020407

  11. Chloroplast-Specific in Vivo Ca2+ Imaging Using Yellow Cameleon Fluorescent Protein Sensors Reveals Organelle-Autonomous Ca2+ Signatures in the Stroma.

    PubMed

    Loro, Giovanna; Wagner, Stephan; Doccula, Fabrizio Gandolfo; Behera, Smrutisanjita; Weinl, Stefan; Kudla, Joerg; Schwarzländer, Markus; Costa, Alex; Zottini, Michela

    2016-08-01

    In eukaryotes, subcellular compartments such as mitochondria, the endoplasmic reticulum, lysosomes, and vacuoles have the capacity for Ca(2+) transport across their membranes to modulate the activity of compartmentalized enzymes or to convey specific cellular signaling events. In plants, it has been suggested that chloroplasts also display Ca(2+) regulation. So far, monitoring of stromal Ca(2+) dynamics in vivo has exclusively relied on using the luminescent Ca(2+) probe aequorin. However, this technique is limited in resolution and can only provide a readout averaged over chloroplast populations from different cells and tissues. Here, we present a toolkit of Arabidopsis (Arabidopsis thaliana) Ca(2+) sensor lines expressing plastid-targeted FRET-based Yellow Cameleon (YC) sensors. We demonstrate that the probes reliably report in vivo Ca(2+) dynamics in the stroma of root plastids in response to extracellular ATP and of leaf mesophyll and guard cell chloroplasts during light-to-low-intensity blue light illumination transition. Applying YC sensing of stromal Ca(2+) dynamics to single chloroplasts, we confirm findings of gradual, sustained stromal Ca(2+) increases at the tissue level after light-to-low-intensity blue light illumination transitions, but monitor transient Ca(2+) spiking as a distinct and previously unknown component of stromal Ca(2+) signatures. Spiking was dependent on the availability of cytosolic Ca(2+) but not synchronized between the chloroplasts of a cell. In contrast, the gradual sustained Ca(2+) increase occurred independent of cytosolic Ca(2+), suggesting intraorganellar Ca(2+) release. We demonstrate the capacity of the YC sensor toolkit to identify novel, fundamental facets of chloroplast Ca(2+) dynamics and to refine the understanding of plastidial Ca(2+) regulation. PMID:27252306

  12. Co-Targeting Prostate Cancer Epithelium and Bone Stroma by Human Osteonectin-Promoter–Mediated Suicide Gene Therapy Effectively Inhibits Androgen-Independent Prostate Cancer Growth

    PubMed Central

    Sung, Shian-Ying; Chang, Junn-Liang; Chen, Kuan-Chou; Yeh, Shauh-Der; Liu, Yun-Ru; Su, Yen-Hao; Hsueh, Chia-Yen; Chung, Leland W. K.; Hsieh, Chia-Ling

    2016-01-01

    Stromal-epithelial interaction has been shown to promote local tumor growth and distant metastasis. We sought to create a promising gene therapy approach that co-targets cancer and its supporting stromal cells for combating castration-resistant prostate tumors. Herein, we demonstrated that human osteonectin is overexpressed in the prostate cancer epithelium and tumor stroma in comparison with their normal counterpart. We designed a novel human osteonectin promoter (hON-522E) containing positive transcriptional regulatory elements identified in both the promoter and exon 1 region of the human osteonectin gene. In vitro reporter assays revealed that the hON-522E promoter is highly active in androgen receptor negative and metastatic prostate cancer and bone stromal cells compared to androgen receptor-positive prostate cancer cells. Moreover, in vivo prostate-tumor–promoting activity of the hON-522E promoter was confirmed by intravenous administration of an adenoviral vector containing the hON-522E promoter-driven luciferase gene (Ad-522E-Luc) into mice bearing orthotopic human prostate tumor xenografts. In addition, an adenoviral vector with the hON-522E-promoter–driven herpes simplex virus thymidine kinase gene (Ad-522E-TK) was highly effective against the growth of androgen-independent human prostate cancer PC3M and bone stromal cell line in vitro and in pre-established PC3M tumors in vivo upon addition of the prodrug ganciclovir. Because of the heterogeneity of human prostate tumors, hON-522E promoter-mediated gene therapy has the potential for the treatment of hormone refractory and bone metastatic prostate cancers. PMID:27054343

  13. Glioma-Derived Platelet-Derived Growth Factor-BB Recruits Oligodendrocyte Progenitor Cells via Platelet-Derived Growth Factor Receptor-α and Remodels Cancer Stroma.

    PubMed

    Zheng, Yang; Yamamoto, Seiji; Ishii, Yoko; Sang, Yang; Hamashima, Takeru; Van De, Nguyen; Nishizono, Hirofumi; Inoue, Ran; Mori, Hisashi; Sasahara, Masakiyo

    2016-05-01

    Glioma is an aggressive and incurable disease, and is frequently accompanied by augmented platelet-derived growth factor (PDGF) signaling. Overexpression of PDGF-B ligand characterizes a specific subclass of glioblastoma multiforme, but the significance of the ligand remains to be elucidated. For this end, we implanted a glioma-cell line transfected with PDGF-BB-overexpressing vector (GL261-PDGF-BB) or control vector (GL261-vector) into wild-type mouse brain, and examined the effect of glioma-derived PDGF on the tumor microenvironment. The volume of GL261-PDGF-BB rapidly increased compared with GL261-vector. Recruitment of many PDGF receptor (PDGFR)-α and Olig2-positive oligodendrocyte precursor cells and frequent hemorrhages were observed in GL261-PDGF-BB but not in GL261-vector. We then implanted GL261-PDGF-BB into the mouse brain with and without Pdgfra gene inactivation, corresponding to PDGFRα-knockout (KO) and Flox mice, respectively. The recruitment of oligodendrocyte precursor cells was largely suppressed in PDGFRα-KO than in Flox, whereas the volume of GL261-PDGF-BB was comparable between the two genotypes. Frequent hemorrhage and increased IgG-leakage were associated with aberrant vascular structures within the area where many recruited oligodendrocyte precursor cells accumulated in Flox. In contrast, these vascular phenotypes were largely normalized in PDGFRα-KO. Increased matrix metalloproteinase-9 in recruited oligodendrocyte precursor cells and decreased claudin-5 in vasculature may underlie the vascular abnormality. Glioma-derived PDGF-B signal induces cancer stroma characteristically seen in high-grade glioma, and should be therapeutically targeted to improve cancer microenvironment. PMID:26945107

  14. Ecosystem function and services provided by the deep sea

    NASA Astrophysics Data System (ADS)

    Thurber, A. R.; Sweetman, A. K.; Narayanaswamy, B. E.; Jones, D. O. B.; Ingels, J.; Hansman, R. L.

    2014-07-01

    The deep sea is often viewed as a vast, dark, remote, and inhospitable environment, yet the deep ocean and seafloor are crucial to our lives through the services that they provide. Our understanding of how the deep sea functions remains limited, but when treated synoptically, a diversity of supporting, provisioning, regulating and cultural services becomes apparent. The biological pump transports carbon from the atmosphere into deep-ocean water masses that are separated over prolonged periods, reducing the impact of anthropogenic carbon release. Microbial oxidation of methane keeps another potent greenhouse gas out of the atmosphere while trapping carbon in authigenic carbonates. Nutrient regeneration by all faunal size classes provides the elements necessary for fueling surface productivity and fisheries, and microbial processes detoxify a diversity of compounds. Each of these processes occur on a very small scale, yet considering the vast area over which they occur they become important for the global functioning of the ocean. The deep sea also provides a wealth of resources, including fish stocks, enormous bioprospecting potential, and elements and energy reserves that are currently being extracted and will be increasingly important in the near future. Society benefits from the intrigue and mystery, the strange life forms, and the great unknown that has acted as a muse for inspiration and imagination since near the beginning of civilization. While many functions occur on the scale of microns to meters and timescales up to years, the derived services that result are only useful after centuries of integrated activity. This vast dark habitat, which covers the majority of the globe, harbors processes that directly impact humans in a variety of ways; however, the same traits that differentiate it from terrestrial or shallow marine systems also result in a greater need for integrated spatial and temporal understanding as it experiences increased use by society. In

  15. The meteorological effects on microwave apparent temperatures looking downward over a smooth sea

    NASA Technical Reports Server (NTRS)

    Wu, S.

    1973-01-01

    The effects of clouds and rain on microwave apparent temperatures for a flat sea surface are examined. The presence of clouds and rain can be expressed as a change of absorption coefficient and the total absorption is computed as the sum of individual effects. Various cloud and rain models proposed by meteorologists are employed to compute the microwave apparent temperature when viewing downward through these model atmospheres. It is shown that stratus, cumulus, overcast, and rain all contribute significantly to the observed temperature. Larger sensitivities to clouds and rain are observed for horizontally polarized apparent temperature at large nadir angles than for vertically polarized apparent temperature.

  16. Implications of Liouville's theorem on the apparent brightness temperatures of solar radio bursts

    NASA Technical Reports Server (NTRS)

    Melrose, D. B.; Dulk, G. A.

    1988-01-01

    Liouville's radiation theorem is discussed with respect to its consequences for the propagation of radio waves from the actual to the apparent sources in the solar corona. It is shown that the observed solid angle and apparent area of the source are compatible with the theorem only if the apparent source corresponds to the envelope of subsources with a small filling factor (f). The brightness temperature of the actual source is found to be greater than that of the apparent source by 1/f.

  17. Deep earthquakes beneath the Fiji Basin, SW Pacific: Earth's most intense deep seismicity in stagnant slabs

    USGS Publications Warehouse

    Okal, E.A.; Kirby, S.H.

    1998-01-01

    Previous work has suggested that many of the deep earthquakes beneath the Fiji Basin occur in slab material that has been detached and foundered to the bottom of the transition zone or has been laid down by trench migration in a similar recumbent position. Since nowhere else in the Earth do so many earthquakes occur in slabs stagnated in the transition zone, these earthquakes merit closer study. Accordingly, we have assembled from historical and modern data a comprehensive catalogue of the relocated hypocenters and focal mechanisms of well-located deep events in the geographic area between the bottoms of the main Vanuatu and Tonga Wadati-Benioff zones. Two regions of deep seismogenesis are recognized there: (i) 163 deep shocks have occurred north of 15??S in the Vityaz Group from 1949 to 1996. These seismological observations and the absence of other features characteristic of active subduction suggest that the Vityaz group represents deep failure in a detached slab that has foundered to a horizontal orientation near the bottom of the transition zone. (ii) Another group of nearly 50 'outboard' deep shocks occur between about 450 and 660 km depth, west of the complexly buckled and offset western edge of the Tonga Wadati-Benioff zone. Their geometry is in the form of two or possibly three small-circle arcs that roughly parallel the inferred motion of Tonga trench migration. Earthquakes in the southernmost of these arcs occur in a recumbent high-seismic-wavespeed slab anomaly that connects both to the main inclined Tonga anomaly to the east and a lower mantle anomaly to the west [Van der Hilst, R., 1995. Complex morphology of subducted lithosphere in the mantle beneath the Tonga trench. Nature, Vol. 374, pp. 154-157.]. Both groups show complexity in their focal mechanisms. The major question raised by these observations is the cause of this apparent temporary arrest in the descent of the Tonga slab into the lower mantle. We approach these questions by considering the

  18. Deep learning for image classification

    NASA Astrophysics Data System (ADS)

    McCoppin, Ryan; Rizki, Mateen

    2014-06-01

    This paper provides an overview of deep learning and introduces the several subfields of deep learning including a specific tutorial of convolutional neural networks. Traditional methods for learning image features are compared to deep learning techniques. In addition, we present our preliminary classification results, our basic implementation of a convolutional restricted Boltzmann machine on the Mixed National Institute of Standards and Technology database (MNIST), and we explain how to use deep learning networks to assist in our development of a robust gender classification system.

  19. Deep drawing of uranium metal

    SciTech Connect

    Jackson, R J; Lundberg, M R

    1987-01-19

    A procedure was developed to fabricate uranium forming blanks with high ''draw-ability'' so that cup shapes could be easily and uniformly deep drawn. The overall procedure involved a posttreatment to develop optimum mechanical and structural properties in the deep-drawn cups. The fabrication sequence is casting high-purity logs, pucking cast logs, cross-rolling pucks to forming blanks, annealing and outgassing forming blanks, cold deep drawing to hemispherical shapes, and stress relieving, outgassing, and annealing deep-drawn parts to restore ductility and impart dimensional stability. The fabrication development and the resulting fabrication procedure are discussed in detail. The mechanical properties and microstructural properties are discussed.

  20. Neurological effects of deep diving.

    PubMed

    Grønning, Marit; Aarli, Johan A

    2011-05-15

    Deep diving is defined as diving to depths more than 50 m of seawater (msw), and is mainly used for occupational and military purposes. A deep dive is characterized by the compression phase, the bottom time and the decompression phase. Neurological and neurophysiologic effects are demonstrated in divers during the compression phase and the bottom time. Immediate and transient neurological effects after deep dives have been shown in some divers. However, the results from the epidemiological studies regarding long term neurological effects from deep diving are conflicting and still not conclusive. Prospective clinical studies with sufficient power and sensitivity are needed to solve this very important issue. PMID:21377169

  1. Deep frequency modulation interferometry.

    PubMed

    Gerberding, Oliver

    2015-06-01

    Laser interferometry with pm/Hz precision and multi-fringe dynamic range at low frequencies is a core technology to measure the motion of various objects (test masses) in space and ground based experiments for gravitational wave detection and geodesy. Even though available interferometer schemes are well understood, their construction remains complex, often involving, for example, the need to build quasi-monolithic optical benches with dozens of components. In recent years techniques have been investigated that aim to reduce this complexity by combining phase modulation techniques with sophisticated digital readout algorithms. This article presents a new scheme that uses strong laser frequency modulations in combination with the deep phase modulation readout algorithm to construct simpler and easily scalable interferometers. PMID:26072834

  2. Groth Deep Locations Image

    NASA Technical Reports Server (NTRS)

    2003-01-01

    NASA's Galaxy Evolution Explorer photographed this ultraviolet color blowup of the Groth Deep Image on June 22 and June 23, 2003. Hundreds of galaxies are detected in this portion of the image, and the faint red galaxies are believed to be 6 billion light years away. The white boxes show the location of these distant galaxies, of which more than a 100 can be detected in this image. NASA astronomers expect to detect 10,000 such galaxies after extrapolating to the full image at a deeper exposure level.

    The Galaxy Evolution Explorer mission is led by the California Institute of Technology, which is also responsible for the science operations and data analysis. NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of Caltech, manages the mission and built the science instrument. The mission was developed under NASA's Explorers Program, managed by the Goddard Space Flight Center, Greenbelt, Md. The mission's international partners include South Korea and France.

  3. Deep Brain Stimulation

    PubMed Central

    Perlmutter, Joel S.; Mink, Jonathan W.

    2015-01-01

    Deep brain stimulation (DBS) has provided remarkable benefits for people with a variety of neurologic conditions. Stimulation of the ventral intermediate nucleus of the thalamus can dramatically relieve tremor associated with essential tremor or Parkinson disease (PD). Similarly, stimulation of the subthalamic nucleus or the internal segment of the globus pallidus can substantially reduce bradykinesia, rigidity, tremor, and gait difficulties in people with PD. Multiple groups are attempting to extend this mode of treatment to other conditions. Yet, the precise mechanism of action of DBS remains uncertain. Such studies have importance that extends beyond clinical therapeutics. Investigations of the mechanisms of action of DBS have the potential to clarify fundamental issues such as the functional anatomy of selected brain circuits and the relationship between activity in those circuits and behavior. Although we review relevant clinical issues, we emphasize the importance of current and future investigations on these topics. PMID:16776585

  4. Method of deep drilling

    DOEpatents

    Colgate, Stirling A.

    1984-01-01

    Deep drilling is facilitated by the following steps practiced separately or in any combination: (1) Periodically and sequentially fracturing zones adjacent the bottom of the bore hole with a thixotropic fastsetting fluid that is accepted into the fracture to overstress the zone, such fracturing and injection being periodic as a function of the progression of the drill. (2) Casing the bore hole with ductile, pre-annealed casing sections, each of which is run down through the previously set casing and swaged in situ to a diameter large enough to allow the next section to run down through it. (3) Drilling the bore hole using a drill string of a low density alloy and a high density drilling mud so that the drill string is partially floated.

  5. Neptune's deep atmosphere revealed

    SciTech Connect

    de Pater, I. ); Atreya, S.K. ); Romani, P.N.

    1989-08-01

    The brightness temperature of Uranus at 20 cm is 260 {plus minus} 10K, while for Neptune it is 318 {plus minus} 16K. Since NH{sub 3} is the dominant absorber at this wavelength the authors have modeled the microwave spectra of Neptune based upon an assumed deep gaseous mixing ratio of NH{sub 3} and subsequent loss into clouds. The difference between the two brightness temperatures implies that the NH{sub 3} mixing ratio below the level of cloud formation on Neptune compared to Uranus is lower by nearly 2 order of magnitude. An alternative explanation is that the 20 cm radiation from Neptune is a combination of thermal plus synchrotron emission as proposed by de Pater and Goertz (1989).

  6. Modeling ocean deep convection

    NASA Astrophysics Data System (ADS)

    Canuto, V. M.; Howard, A.; Hogan, P.; Cheng, Y.; Dubovikov, M. S.; Montenegro, L. M.

    The goal of this study is to assess models for Deep Convection with special emphasis on their use in coarse resolution ocean general circulation models. A model for deep convection must contain both vertical transport and lateral advection by mesoscale eddies generated by baroclinic instabilities. The first process operates mostly in the initial phases while the second dominates the final stages. Here, the emphasis is on models for vertical mixing. When mesoscales are not resolved, they are treated with the Gent and McWilliams parameterization. The model results are tested against the measurements of Lavender, Davis and Owens, 2002 (LDO) in the Labrador Sea. Specifically, we shall inquire whether the models are able to reproduce the region of " deepest convection," which we shall refer to as DC (mixed layer depths 800-1300 m). The region where it was measured by Lavender et al. (2002) will be referred to as the LDO region. The main results of this study can be summarized as follows. 3° × 3° resolution. A GFDL-type OGCM with the GISS vertical mixing model predicts DC in the LDO region where the vertical heat diffusivity is found to be 10 m 2 s -1, a value that is quite close to the one suggested by heuristic studies. No parameter was changed from the original GISS model. However, the GISS model also predicts some DC in a region to the east of the LDO region. 3° × 3° resolution. A GFDL-type OGCM with the KPP model (everything else being the same) does not predict DC in the LDO region where the vertical heat diffusivity is found to be 0.5 × 10 -4 m 2 s -1 which is the background value. The KPP model yields DC only to the east of the LDO region. 1° × 1° resolution. In this case, a MY2.5 mixing scheme predicts DC in the LDO region. However, it also predicts DC to the west, north and south of it, where it is not observed. The behavior of the KPP and MY models are somewhat anti-symmetric. The MY models yield too low a mixing in stably stratified flows since they

  7. Natural Hazards at the Other Extreme: AN Apparently Seasonal Hazard at Taihape Landslide, New Zealand

    NASA Astrophysics Data System (ADS)

    McSaveney, M. J.; Massey, C.

    2010-12-01

    Taihape landslide is a slow-moving, deep-seated translational rock slide on weakly consolidated marine sedimentary rocks in west-central North Island, New Zealand. It includes about a third of the rural town of Taihape. Only a portion of the ancient landslide appears to be active. About $20 M of insured property and substantial infrastructure is potentially at risk from landslide damage there. To find out more about the landslide movement drivers, its surface movement and internal deformation have been closely monitored. Surface movement is monitored using 35 fixed prisms that are followed using a robotic total station. Rainfall, pore pressures, transient ground acceleration, and subsurface displacements are also monitored. The precision and temporal resolution of the monitoring clearly resolves the triggers of movement as well as the resulting complex movement patterns. The landslide motion is best described as post-failure, episodic creep, with steady, slow creep at rates <10 mm/yr punctuated by periods of rest and faster creep at rates of 1 to 3 mm/day sustained over weeks. At current maximum rates of movement it is annoyingly destructive of property, but it is not apparently a threat to life. The longer historical and geomorphological records are fully concordant with the current rates, suggesting that they may have been sustained over many tens of thousands of years. Over much of the landslide, measured prism movement is dominated by a recurring signal in which some prisms appear to speed up and slow down on a seasonal cycle, while others even appear to move upslope at certain times of the year. Although individual prisms are seasonally cyclic, they are not all in phase. The seasonal signal is in both horizontal and vertical components of motion, and survey control points oscillate about fixed sites. The signal correlates weakly with rainfall and pore pressure. We interpret it as surface deformation associated with seasonal shrinkage and swelling of the local

  8. Clinical feasibility of using mean apparent propagator (MAP) MRI to characterize brain tissue microstructure.

    PubMed

    Avram, Alexandru V; Sarlls, Joelle E; Barnett, Alan S; Özarslan, Evren; Thomas, Cibu; Irfanoglu, M Okan; Hutchinson, Elizabeth; Pierpaoli, Carlo; Basser, Peter J

    2016-02-15

    Diffusion tensor imaging (DTI) is the most widely used method for characterizing noninvasively structural and architectural features of brain tissues. However, the assumption of a Gaussian spin displacement distribution intrinsic to DTI weakens its ability to describe intricate tissue microanatomy. Consequently, the biological interpretation of microstructural parameters, such as fractional anisotropy or mean diffusivity, is often equivocal. We evaluate the clinical feasibility of assessing brain tissue microstructure with mean apparent propagator (MAP) MRI, a powerful analytical framework that efficiently measures the probability density function (PDF) of spin displacements and quantifies useful metrics of this PDF indicative of diffusion in complex microstructure (e.g., restrictions, multiple compartments). Rotation invariant and scalar parameters computed from the MAP show consistent variation across neuroanatomical brain regions and increased ability to differentiate tissues with distinct structural and architectural features compared with DTI-derived parameters. The return-to-origin probability (RTOP) appears to reflect cellularity and restrictions better than MD, while the non-Gaussianity (NG) measures diffusion heterogeneity by comprehensively quantifying the deviation between the spin displacement PDF and its Gaussian approximation. Both RTOP and NG can be decomposed in the local anatomical frame for reference determined by the orientation of the diffusion tensor and reveal additional information complementary to DTI. The propagator anisotropy (PA) shows high tissue contrast even in deep brain nuclei and cortical gray matter and is more uniform in white matter than the FA, which drops significantly in regions containing crossing fibers. Orientational profiles of the propagator computed analytically from the MAP MRI series coefficients allow separation of different fiber populations in regions of crossing white matter pathways, which in turn improves our

  9. 45 CFR 73.735-904 - Resolution of apparent or actual conflicts of interest.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Resolution of apparent or actual conflicts of interest. 73.735-904 Section 73.735-904 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION STANDARDS OF CONDUCT Reporting Financial Interests § 73.735-904 Resolution of apparent or actual conflicts of interest....

  10. College Student Disclosure of Non-Apparent Disabilities to Receive Classroom Accommodations

    ERIC Educational Resources Information Center

    Kranke, Derrick; Jackson, Sarah E.; Taylor, Debbie A.; Anderson-Fye, Eileen; Floersch, Jerry

    2013-01-01

    College students with psychiatric (non-apparent) disabilities have a much higher dropout rate and tend to underperform academically when compared with peers who do not have non-apparent disabilities. These students are also vulnerable because their disability could delay the development of milestones critical to adulthood. Limited research…

  11. Young Children's Knowledge About the Apparent-Real and Pretend-Real Distinctions.

    ERIC Educational Resources Information Center

    Flavell, John H.; And Others

    1987-01-01

    Tested the hypothesis that understanding of the pretend-real distinction develops earlier than understanding of the theoretically related apparent-real distinction. Found 3-year-old children consistently performed better on pretend-real tasks than on apparent-real tasks, even when the tasks were identical except for the distinction tested. (SKC)

  12. Taking a Hands-On Approach: Apparent Grasping Ability Scales the Perception of Object Size

    ERIC Educational Resources Information Center

    Linkenauger, Sally A.; Witt, Jessica K.; Proffitt, Dennis R.

    2011-01-01

    We examined whether the apparent size of an object is scaled to the morphology of the relevant body part with which one intends to act on it. To be specific, we tested if the visually perceived size of graspable objects is scaled to the extent of apparent grasping ability for the individual. Previous research has shown that right-handed…

  13. Financial Barriers for Students with Non-Apparent Disabilities within Canadian Postsecondary Education

    ERIC Educational Resources Information Center

    Chambers, Tony; Bolton, Melissa; Sukhai, Mahadeo A.

    2013-01-01

    This study examined the education-related debt, sources of debt, and the process of acquiring accommodations for students with non-apparent (such as learning disabilities and mental health disabilities) and apparent disabilities in Canadian postsecondary education. A third group emerged during analyses, students with medical disabilities, which…

  14. Observation on ultrastructure and histopathology of cornea following femtosecond laser-assisted deep lamellar keratoplasty for acute corneal alkaline burns

    PubMed Central

    Li, Wen-Jing; Hu, Yu-Kun; Song, Hui; Gao, Xiao-Wei; Zhao, Xu-Dong; Dong, Jing; Guo, Yun-Lin; Cai, Yan

    2016-01-01

    AIM To demonstrate the changes in ultrastructure and histopathology of the cornea in acute corneal alkaline burns after femtosecond laser-assisted deep lamellar keratoplasty. METHODS The New Zealand white rabbits treated with alkaline corneal burn were randomized into two groups, Group A (16 eyes) with femtosecond laser-assisted deep lamellar keratoplasty 24h after burn and Group B (16 eyes) without keratoplasty as controls. All eyes were evaluated with transmission electron microscopy (TEM) at 1, 2, 3, and 4wk follow-up, then all corneas were tested by hematoxylin and eosin staining histology. RESULTS The corneal grafts in Group A were transparent, while those in Group B showed corneal stromal edema and loosely arranged collagen fibers. One week after treatment, TEM revealed the intercellular desmosomes in the epithelial layers and intact non-dissolving nuclei in Group A. At week 4, the center of the corneas in Group A was transparent with regularly arranged collagen fibers and fibroblasts in the stroma. In Group B, squamous cells were observed on the corneal surface and some epithelial cells were detached. CONCLUSION Femtosecond laser-assisted deep lamellar keratoplasty can suppress inflammatory responses, prevent toxic substance-induced injury to the corneal endothelium and inner tissues with quicker recovery and better visual outcomes. PMID:27162716

  15. Full-Thickness Excision versus Shaving by Laparoscopy for Intestinal Deep Infiltrating Endometriosis: Rationale and Potential Treatment Options

    PubMed Central

    Trovato, Maria Antonietta; Palmara, Vittorio Italo; Rapisarda, Agnese Maria Chiara; Sturlese, Emanuele; De Dominici, Rosanna; Alecci, Stefano; D'Amico, Paolo; Triolo, Onofrio

    2016-01-01

    Endometriosis is defined as the presence of endometrial mucosa (glands and stroma) abnormally implanted in locations other than the uterine cavity. Deep infiltrating endometriosis (DIE) is considered the most aggressive presentation of the disease, penetrating more than 5 mm in affected tissues, and it is reported in approximately 20% of all women with endometriosis. DIE can cause a complete distortion of the pelvic anatomy and it mainly involves uterosacral ligaments, bladder, rectovaginal septum, rectum, and rectosigmoid colon. This review describes the state of the art in laparoscopic approach for DIE with a special interest in intestinal involvement, according to recent literature findings. Our attention has been focused particularly on full-thickness excision versus shaving technique in deep endometriosis intestinal involvement. Particularly, the aim of this paper is clarifying from the clinical and methodological points of view the best surgical treatment of deep intestinal endometriosis, since there is no standard of care in the literature and in different surgical settings. Indeed, this review tries to suggest when it is advisable to manage the full-thickness excision or the shaving technique, also analyzing perioperative management, main complications, and surgical outcomes. PMID:27579309

  16. Full-Thickness Excision versus Shaving by Laparoscopy for Intestinal Deep Infiltrating Endometriosis: Rationale and Potential Treatment Options.

    PubMed

    Laganà, Antonio Simone; Vitale, Salvatore Giovanni; Trovato, Maria Antonietta; Palmara, Vittorio Italo; Rapisarda, Agnese Maria Chiara; Granese, Roberta; Sturlese, Emanuele; De Dominici, Rosanna; Alecci, Stefano; Padula, Francesco; Chiofalo, Benito; Grasso, Roberta; Cignini, Pietro; D'Amico, Paolo; Triolo, Onofrio

    2016-01-01

    Endometriosis is defined as the presence of endometrial mucosa (glands and stroma) abnormally implanted in locations other than the uterine cavity. Deep infiltrating endometriosis (DIE) is considered the most aggressive presentation of the disease, penetrating more than 5 mm in affected tissues, and it is reported in approximately 20% of all women with endometriosis. DIE can cause a complete distortion of the pelvic anatomy and it mainly involves uterosacral ligaments, bladder, rectovaginal septum, rectum, and rectosigmoid colon. This review describes the state of the art in laparoscopic approach for DIE with a special interest in intestinal involvement, according to recent literature findings. Our attention has been focused particularly on full-thickness excision versus shaving technique in deep endometriosis intestinal involvement. Particularly, the aim of this paper is clarifying from the clinical and methodological points of view the best surgical treatment of deep intestinal endometriosis, since there is no standard of care in the literature and in different surgical settings. Indeed, this review tries to suggest when it is advisable to manage the full-thickness excision or the shaving technique, also analyzing perioperative management, main complications, and surgical outcomes. PMID:27579309

  17. Modeling ocean deep convection

    NASA Astrophysics Data System (ADS)

    Canuto, V. M.; Howard, A.; Hogan, P.; Cheng, Y.; Dubovikov, M. S.; Montenegro, L. M.

    The goal of this study is to assess models for Deep Convection with special emphasis on their use in coarse resolution ocean general circulation models. A model for deep convection must contain both vertical transport and lateral advection by mesoscale eddies generated by baroclinic instabilities. The first process operates mostly in the initial phases while the second dominates the final stages. Here, the emphasis is on models for vertical mixing. When mesoscales are not resolved, they are treated with the Gent and McWilliams parameterization. The model results are tested against the measurements of Lavender, Davis and Owens, 2002 (LDO) in the Labrador Sea. Specifically, we shall inquire whether the models are able to reproduce the region of " deepest convection," which we shall refer to as DC (mixed layer depths 800-1300 m). The region where it was measured by Lavender et al. (2002) will be referred to as the LDO region. The main results of this study can be summarized as follows. 3° × 3° resolution. A GFDL-type OGCM with the GISS vertical mixing model predicts DC in the LDO region where the vertical heat diffusivity is found to be 10 m 2 s -1, a value that is quite close to the one suggested by heuristic studies. No parameter was changed from the original GISS model. However, the GISS model also predicts some DC in a region to the east of the LDO region. 3° × 3° resolution. A GFDL-type OGCM with the KPP model (everything else being the same) does not predict DC in the LDO region where the vertical heat diffusivity is found to be 0.5 × 10 -4 m 2 s -1 which is the background value. The KPP model yields DC only to the east of the LDO region. 1° × 1° resolution. In this case, a MY2.5 mixing scheme predicts DC in the LDO region. However, it also predicts DC to the west, north and south of it, where it is not observed. The behavior of the KPP and MY models are somewhat anti-symmetric. The MY models yield too low a mixing in stably stratified flows since they

  18. Deep Ecology: Beyond Mere Environmentalism.

    ERIC Educational Resources Information Center

    Weber, Suzanne

    1994-01-01

    Outlines the principles of deep ecology, a movement that questions the societal values that have resulted in damage to the earth's life-supporting biosphere. In contrast to shallow reform, deep ecology encourages individuals to examine their values and relationship to nature to address the environmental crisis. (LP)

  19. Context and Deep Learning Design

    ERIC Educational Resources Information Center

    Boyle, Tom; Ravenscroft, Andrew

    2012-01-01

    Conceptual clarification is essential if we are to establish a stable and deep discipline of technology enhanced learning. The technology is alluring; this can distract from deep design in a surface rush to exploit the affordances of the new technology. We need a basis for design, and a conceptual unit of organization, that are applicable across…

  20. Deep space network energy program

    NASA Technical Reports Server (NTRS)

    Friesema, S. E.

    1980-01-01

    If the Deep Space Network is to exist in a cost effective and reliable manner in the next decade, the problems presented by international energy cost increases and energy availability must be addressed. The Deep Space Network Energy Program was established to implement solutions compatible with the ongoing development of the total network.

  1. Deep sulfur cycle

    NASA Astrophysics Data System (ADS)

    Shimizu, N.; Mandeville, C. W.

    2009-12-01

    Geochemical cycle of sulfur in near-surface reservoirs has been a subject of intense studies for decades. It has been shown that sulfur isotopic compositions of sedimentary sulfides and sulfates record interactions of the atmosphere, hydrosphere, biosphere and lithosphere, with δ34S of sedimentary sulfides continuously decreasing from 0‰ toward present-day values of ~-30 to -40‰ over the Phanerozoic (e.g., Canfield, 2004). It has also been shown that microbial reduction of the present-day seawater sulfate (δ34S=+21‰) results in large shifts in isotopic compositions of secondary pyrites in altered oceanic crust (to δ34S=-70‰: Rouxel et al., 2009). How much of these near surface isotopic variations survive during deep geochemical cycle of sulfur interacting with the mantle infinite reservoir with δ34S=0‰? Could extent of their survival be used as a tracer of processes and dynamics involved in deep geochemical cycle? As a first step toward answering these questions, δ34S was determined in-situ using a Cameca IMS 1280 ion microprobe at Woods Hole Oceanographic Institution in materials representing various domains of deep geochemical cycle. They include pyrites in altered MORB as potential subducting materials and pyrites in UHP eclogites as samples that have experienced subduction zone processes, and mantle-derived melts are represented by olivine-hosted melt inclusions in MORB and those in IAB, and undegassed submarine OIB glasses. Salient features of the results include: (1) pyrites in altered MORB (with O. Rouxel; from ODP site 801 and ODP Hole 1301B) range from -70 to +19‰, (2) pyrites in UHP eclogites from the Western Gneiss Region, Norway (with B. Hacker and A. Kylander-Clark) show a limited overall range from -3.4 to + 2.8‰ among five samples, with one of them covering almost the entire range, indicating limited scale lengths of isotopic equilibration during subduction, (3) olivine-hosted melt inclusions in arc basalts from Galunggung (-2

  2. Mimicking Metastases Including Tumor Stroma: A New Technique to Generate a Three-Dimensional Colorectal Cancer Model Based on a Biological Decellularized Intestinal Scaffold

    PubMed Central

    Nietzer, Sarah; Baur, Florentin; Sieber, Stefan; Hansmann, Jan; Schwarz, Thomas; Stoffer, Carolin; Häfner, Heide; Gasser, Martin; Waaga-Gasser, Ana Maria; Walles, Heike

    2016-01-01

    generation, a bioreactor was constructed for dynamic culture approaches. This induced a close tissue-like association of cultured tumor cells with fibroblasts reflecting tumor biopsies. Therapy with 5-fluorouracil (5-FU) was effective only in 3D coculture. In conclusion, our 3D tumor model reflects human tissue-related tumor characteristics, including lower tumor cell proliferation. It is now available for drug testing in metastatic context—especially for substances targeting tumor–stroma interactions. PMID:27137941

  3. Mimicking Metastases Including Tumor Stroma: A New Technique to Generate a Three-Dimensional Colorectal Cancer Model Based on a Biological Decellularized Intestinal Scaffold.

    PubMed

    Nietzer, Sarah; Baur, Florentin; Sieber, Stefan; Hansmann, Jan; Schwarz, Thomas; Stoffer, Carolin; Häfner, Heide; Gasser, Martin; Waaga-Gasser, Ana Maria; Walles, Heike; Dandekar, Gudrun

    2016-07-01

    generation, a bioreactor was constructed for dynamic culture approaches. This induced a close tissue-like association of cultured tumor cells with fibroblasts reflecting tumor biopsies. Therapy with 5-fluorouracil (5-FU) was effective only in 3D coculture. In conclusion, our 3D tumor model reflects human tissue-related tumor characteristics, including lower tumor cell proliferation. It is now available for drug testing in metastatic context-especially for substances targeting tumor-stroma interactions. PMID:27137941

  4. Apparent Depth.

    ERIC Educational Resources Information Center

    Nassar, Antonio B.

    1994-01-01

    Discusses a well-known optical refraction problem where the depth of an object in a liquid is determined. Proposes that many texts incorrectly solve the problem. Provides theory, equations, and diagrams. (MVL)

  5. Air Apparent.

    ERIC Educational Resources Information Center

    Harbster, David A.

    1988-01-01

    Explains the principle upon which a barometer operates. Describes how to construct two barometric devices for use in the classroom that show air's changing pressure. Cites some conditions for predicting weather. (RT)

  6. Exploring deep potential aquifer in water scarce crystalline rocks

    NASA Astrophysics Data System (ADS)

    Chandra, Subash; Nagaiah, E.; Reddy, D. V.; Rao, V. Ananda; Ahmed, Shakeel

    2012-12-01

    Characterization of the shear zone with pole-pole electrical resistivity tomography (ERT) was carried out to explore deep groundwater potential zone in a water scarce granitic area. As existing field conditions does not always allow to plant the remote electrodes at sufficiently far of distance, the effect of insufficient distance of remote electrodes on apparent resistivity measurement was studied and shown that the transverse pole-pole array affects less compared to the collinear pole-pole array. Correction factor have been computed for transverse pole-pole array for various positions of the remote electrodes. The above results helped in exploring deep aquifer site, where a 270 m deep well was drilled. Temporal hydro-chemical samples collected during the pumping indicated the hydraulic connectivity between the demarcated groundwater potential fractures. Incorporating all the information derived from different investigations, a subsurface model was synthetically simulated and generated 2D electrical resistivity response for different arrays and compared with the field responses to further validate the geoelectrical response of deep aquifer set-up associated with lineament.

  7. Deep inelastic phenomena

    SciTech Connect

    Prescott, C.Y.

    1980-10-01

    Nucleon structure as seen in the context of deep inelastic scattering is discussed. The lectures begin with consideration of the quark-parton model. The model forms the basis of understanding lepton-nucleon inelastic scattering. As improved data in lepton-nucleon scattering at high energies became available, the quark-parton model failed to explain some crucial features of these data. At approximately the same time a candidate theory of strong interactions based on a SU(3) gauge theory of color was being discussed in the literature, and new ideas on the explanation of inelastic scattering data became popular. A new theory of strong interactions, now called quantum chromodynamics provides a new framework for understanding the data, with a much stronger theoretical foundation, and seems to explain well the features of the data. The lectures conclude with a look at some recent experiments which provide new data at very high energies. These lectures are concerned primarily with charged lepton inelastic scattering and to a lesser extent with neutrino results. Furthermore, due to time and space limitations, topics such as final state hadron studies, and multi-muon production are omitted here. The lectures concentrate on the more central issues: the quark-parton model and concepts of scaling, scale breaking and the ideas of quantum chromodynamics, the Q/sup 2/ dependence of structure function, moments, and the important parameter R.

  8. Deep mine cooling system

    SciTech Connect

    Conan, J.

    1984-11-06

    A deep mine cooling system comprising a compressor supplied with air and rotatively driven by a motor and an expansion turbine supplied with compressed air from said compressor and driving an actuating unit, wherein the compressed air, after leaving the compressor but prior to reaching the expansion turbine, passes through a steam generator whose output provides the energy required to operate an absorption refrigeration machine used to cool utility water for mining, said compressed air on leaving the steam generator going to a first heat exchanger in which it yields calories to a water circuit comprising a second heat exchanger, said second heat exchanger giving off the calories absorbed by the water in the first heat exchanger to the air fed by the second heat exchanger to a drying cell that is regenerated by said air from the second heat exchanger, said drying cell being part of a set of two cells working in alternation, the other cell in the set receiving the compressed air from the first heat exchanger, such that the compressed air is fed to said expansion turbine after leaving said drying unit, and wherein the air exhausted from said expansion turbine is sent to a third heat exchanger after which it is distributed according to the needs of the mine, said third exchanger being traversed by the water collected in the mine, cooled in said exchanger and circulated upon leaving said exchanger to meet the cool water requirements of the mine.

  9. Deep atomic force microscopy

    SciTech Connect

    Barnard, H.; Drake, B.; Randall, C.; Hansma, P. K.

    2013-12-15

    The Atomic Force Microscope (AFM) possesses several desirable imaging features including the ability to produce height profiles as well as two-dimensional images, in fluid or air, at high resolution. AFM has been used to study a vast selection of samples on the scale of angstroms to micrometers. However, current AFMs cannot access samples with vertical topography of the order of 100 μm or greater. Research efforts have produced AFM scanners capable of vertical motion greater than 100 μm, but commercially available probe tip lengths are still typically less than 10 μm high. Even the longest probe tips are below 100 μm and even at this range are problematic. In this paper, we present a method to hand-fabricate “Deep AFM” probes with tips of the order of 100 μm and longer so that AFM can be used to image samples with large scale vertical topography, such as fractured bone samples.

  10. Human Embryonic Stem Cell-Derived Mesenchymal Stroma Cells (hES-MSCs) Engraft In Vivo and Support Hematopoiesis without Suppressing Immune Function: Implications for Off-The Shelf ES-MSC Therapies

    PubMed Central

    Li, Ou; Tormin, Ariane; Sundberg, Berit; Hyllner, Johan; Le Blanc, Katarina; Scheding, Stefan

    2013-01-01

    Mesenchymal stroma cells (MSCs) have a high potential for novel cell therapy approaches in clinical transplantation. Commonly used bone marrow-derived MSCs (BM-MSCs), however, have a restricted proliferative capacity and cultures are difficult to standardize. Recently developed human embryonic stem cell-derived mesenchymal stroma cells (hES-MSCs) might represent an alternative and unlimited source of hMSCs. We therefore compared human ES-cell-derived MSCs (hES-MP002.5 cells) to normal human bone marrow-derived MSCs (BM-MSCs). hES-MP002.5 cells had lower yet reasonable CFU-F capacity compared with BM-MSC (8±3 versus 29±13 CFU-F per 100 cells). Both cell types showed similar immunophenotypic properties, i.e. cells were positive for CD105, CD73, CD166, HLA-ABC, CD44, CD146, CD90, and negative for CD45, CD34, CD14, CD31, CD117, CD19, CD 271, SSEA-4 and HLA-DR. hES-MP002.5 cells, like BM-MSCs, could be differentiated into adipocytes, osteoblasts and chondrocytes in vitro. Neither hES-MP002.5 cells nor BM-MSCs homed to the bone marrow of immune-deficient NSG mice following intravenous transplantation, whereas intra-femoral transplantation into NSG mice resulted in engraftment for both cell types. In vitro long-term culture-initiating cell assays and in vivo co-transplantation experiments with cord blood CD34+ hematopoietic cells demonstrated furthermore that hES-MP002.5 cells, like BM-MSCs, possess potent stroma support function. In contrast to BM-MSCs, however, hES-MP002.5 cells showed no or only little activity in mixed lymphocyte cultures and phytohemagglutinin (PHA) lymphocyte stimulation assays. In summary, ES-cell derived MSCs might be an attractive unlimited source for stroma transplantation approaches without suppressing immune function. PMID:23383153

  11. The deep structure of Venusian plateau highlands

    NASA Technical Reports Server (NTRS)

    Grimm, Robert E.

    1994-01-01

    Magellan gravity data confirm that several of the large, tectonically deformed, plateau-like highlands on venus are shallowly compensated, most likely by crustal thickness variations. Apparent depths of isostatic compensation, computed in the spatial domain, range from 30 to 50 km for Alpha, Tellus, Ovda, and Thetis Regiones. Using a two-layer model for isostatic compensation, Alpha, Tellus, and Ovda are best represented as nearly completely compensated in crust that is regionally 20-40 km thick around these highlands, with little contribution from deeper mantle sources. In contrast to these three areas, a stronger regional gravity high associated with Thetis requires a significant upper mantle component to compensation. This is evident in the spectral admittance as a pronounced deep, long-wavelength anomaly. In the two-layer isostatic model, a broad, deeply compensated upland underlies a shallowly compensated central block of Thetis. If this deep component is interpreted as a thermal anomaly, the loci of maximum upwelling agree well with sites of recent extension. The plateau highlands are thus physiographically and isostatically equivalent to terrestrial continents, though probably not compositionally. They also share the record of a long tectonic history. The large regional gravity anomaly of Thetis indicates that active mantle proceses continue even beneath some areas (tessera) thought to be a relic of a former geological regime. The excellent agreement of modeled crustal thicknesses around Alpha, Tellus, and Ovda Regiones suggests that 20-40 km is a representative global value for the plains. Such a crust is thicker than previously estimated and about twice as thick as the expected thickness of crust produced at venusian spreading centers

  12. Tritium/Helium-3 Apparent Ages of Shallow Ground Water, Portland Basin, Oregon, 1997-98

    USGS Publications Warehouse

    Hinkle, Stephen R.

    2009-01-01

    Water samples for tritium/helium-3 age dating were collected from 12 shallow monitoring wells in the Portland basin, Oregon, in 1997, and again in 1998. Robust tritium/helium-3 apparent (piston-flow) ages were obtained for water samples from 10 of the 12 wells; apparent ages ranged from 1.1 to 21.2 years. Method precision was demonstrated by close agreement between data collected in 1997 and 1998. Tritium/helium-3 apparent ages generally increase with increasing depth below the water table, and agree well with age/depth relations based on assumptions of effects of recharge rate on vertical ground-water movement.

  13. Apparent mass of the human body in the vertical direction: Effect of seat backrest

    NASA Astrophysics Data System (ADS)

    Toward, Martin G. R.; Griffin, Michael J.

    2009-11-01

    The transmission of vibration through a seat depends on various characteristics of the seat and the dynamic response of the human body. The dynamic response of the body can be represented by its apparent mass, but the effect of the seat on the apparent mass of the body is not well understood. This study was designed to quantify the effect of foam and rigid backrests on the vertical apparent mass of the human measured at the seat surface supporting the body. The apparent masses of 12 subjects were measured during exposure to random vertical vibration (1.0 ms -2 rms from 0.125 to 40 Hz) in a seat with a rigid backrest, in the same rigid seat with three thicknesses of foam backrest (50, 100 and 150 mm), and in the same seat with no backrest. The backrests were inclined at various angles: 0°, 5°, 10°, 15°, 20°, 25° and 30° for the rigid and 100 mm foam backrests, and 0°, 10°, 20° and 30° for the 50 and 150 mm foam backrests. With all vertical backrests (i.e., 0° inclination), there were resonances in the apparent mass of the body around 5 and 10 Hz. With no backrest, the apparent mass was increased at frequencies less than the resonance frequency but decreased at frequencies between 8 and 20 Hz, relative to the apparent mass with the vertical rigid and foam backrests. With the rigid backrest, the primary resonance frequencies in the apparent mass increased with increasing backrest inclination. With the foam backrests, the resonance frequencies decreased with increasing backrest inclination. At frequencies less than the primary resonance, the apparent mass decreased with increasing backrest inclination, particularly with the rigid backrest. Between 8 and 15 Hz, the apparent mass decreased with increasing inclination, most notably with the foam backrests. At inclinations less than 30°, there was little effect of foam thickness on the apparent mass, but at 30° an increase in the thickness of the foam decreased the frequency of the first resonances. Since

  14. Effect of temperature and heating rate on apparent lethal concentrations of pyrolysis products

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Solis, A. N.; Marcussen, W. H.; Furst, A.

    1976-01-01

    The apparent lethal concentrations for 50 percent of the test animals of the pyrolysis products from twelve polymeric materials were studied as a function of temperature and heating rate. The materials were polyethylene, nylon 6, ABS, polycarbonate, polyether sulfone, polyaryl sulfone, wool fabric, aromatic polyamide fabric, polychloroprene foam, polyvinyl fluoride film, Douglas fir, and red oak. The apparent lethal concentration values of most materials vary significantly with temperature and heating rate. The apparent lethal concentration values, based on weight of sample charged, appears to effectively integrate the thermophysical, thermochemical, and physiological responses from a known quantity of material under specified imposed conditions.

  15. Microbial Life in the Deep Subsurface: Deep, Hot and Radioactive

    NASA Technical Reports Server (NTRS)

    DeStefano, Andrea L.; Ford, Jill C.; Winsor, Seana K.; Allen, Carlton C.; Miller, Judith; McNamara, Karen M.; Gibson, Everett K., Jr.

    2000-01-01

    Recent studies, motivated in part by the search for extraterrestrial life, continue to expand the recognized limits of Earth's biosphere. This work explored evidence for life a high-temperature, radioactive environment in the deep subsurface.

  16. Common complications of deep lamellar keratoplasty in the early phase of the learning curve

    PubMed Central

    Hosny, Mohamed

    2011-01-01

    Purpose: To evaluate and record the common complications that face surgeons when they perform their first few series of deep lamellar keratoplasty and measures to avoid these. Setting: Dar El Oyoun Hospital, Cairo, Egypt. Methods: Retrospective study of the first 40 eyes of 40 patients carried out by two corneal surgeons working in the same center. All patients were planned to undergo a deep anterior lamellar keratoplasty using the big bubble technique. Twelve patients suffered from keratoconus while 28 patients had anterior corneal pathologies. Recorded complications were classified as either intraoperative or postoperative. Results: Perforation of Descemet’s membrane was the most common intraoperative complication. It occurred in nine eyes (22.5%): five eyes (12.5%) had microperforations while four eyes (10%) had macroperforations, three eyes (7.5%) had central perforations, and six eyes (15%) had peripheral perforations. Other complications included incomplete separation of Descemet’s membrane and remnants of peripheral stromal tissue. Postoperative complications included double anterior chamber which occurred in four eyes (10%) and Descemet’s membrane corrugations. Postoperative astigmatism ranged from 1.25 to 4.5 diopters with a mean of 2.86 diopters in the whole series, but in the six cases with identified residual stroma in the periphery of the host bed, the astigmatism ranged from 2.75 to 4.5 diopters with a mean of 3.62 diopters. Conclusion: Deep lamellar keratoplasty is sensitive to procedural details. Learning the common complications and how to avoid them helps novice surgeons to learn the procedure faster. PMID:21750612

  17. Deep Learning in Drug Discovery.

    PubMed

    Gawehn, Erik; Hiss, Jan A; Schneider, Gisbert

    2016-01-01

    Artificial neural networks had their first heyday in molecular informatics and drug discovery approximately two decades ago. Currently, we are witnessing renewed interest in adapting advanced neural network architectures for pharmaceutical research by borrowing from the field of "deep learning". Compared with some of the other life sciences, their application in drug discovery is still limited. Here, we provide an overview of this emerging field of molecular informatics, present the basic concepts of prominent deep learning methods and offer motivation to explore these techniques for their usefulness in computer-assisted drug discovery and design. We specifically emphasize deep neural networks, restricted Boltzmann machine networks and convolutional networks. PMID:27491648

  18. Jack Dymond's Deep Insights

    NASA Astrophysics Data System (ADS)

    Thomson, R. E.; Delaney, J. R.

    2004-12-01

    Most people do not know that Jack Dymond was a major influence on several aspects of current deep-sea research. Along with Margaret Leinen and Jack, we were part of the first Alvin dive program on the Endeavour hydrothermal field in 1984. Jack was working with Rick, on a sediment-trap study of the overall carbon fluxes in the vicinity of the Endeavour hydrothermal systems in an effort to address a question that Cindy Lee had posed about the overall carbon production from hydrothermal vents. At the time we were recognizing and naming many of the 20- to 40-meter-high sulfide structures in the Endeavour field (Hulk, Grotto, Dante, Dudley, Bastille), Jack commented that it was a shame that the world could not see these magnificent edifices or watch endlessly awesome black smokers. His feeling was that some vent sites should be converted to National Parks to preserve them from invasion by enthusiastic scientists, yet he clearly had the vision that the public should be given a sense of the grandeur involved locally, as well as the vastness of the 70,000-km ridge-crest system running through every ocean. Within a year we started talking about the RIDGE Program, and Jack was an early and enthusiastic participant in the design and development of RIDGE. Jack was among the first to encourage multi-disciplinary research at the hydrothermal vent sites. Recognizing that deep currents are important to vent processes, he urged physical oceanographers to work with the chemists, biologists, and geologists and was personally responsible for Rick becoming interested in studying vents. We, the co-authors of this abstract, became close friends as a result of having been introduced to each other by Jack. Several years ago, we co-authored the first paper ever written on the possible influence of hydrothermal activity on the circulation of the Europan Ocean, a paper that we here dedicate to the memory of Jack. Finally, it was in part because of Jack's conviction that the world should know

  19. Deep UV LEDs

    NASA Astrophysics Data System (ADS)

    Han, Jung; Amano, Hiroshi; Schowalter, Leo

    2014-06-01

    Deep ultraviolet (DUV) photons interact strongly with a broad range of chemical and biological molecules; compact DUV light sources could enable a wide range of applications in chemi/bio-sensing, sterilization, agriculture, and industrial curing. The much shorter wavelength also results in useful characteristics related to optical diffraction (for lithography) and scattering (non-line-of-sight communication). The family of III-N (AlGaInN) compound semiconductors offers a tunable energy gap from infrared to DUV. While InGaN-based blue light emitters have been the primary focus for the obvious application of solid state lighting, there is a growing interest in the development of efficient UV and DUV light-emitting devices. In the past few years we have witnessed an increasing investment from both government and industry sectors to further the state of DUV light-emitting devices. The contributions in Semiconductor Science and Technology 's special issue on DUV devices provide an up-to-date snapshot covering many relevant topics in this field. Given the expected importance of bulk AlN substrate in DUV technology, we are pleased to include a review article by Hartmann et al on the growth of AlN bulk crystal by physical vapour transport. The issue of polarization field within the deep ultraviolet LEDs is examined in the article by Braut et al. Several commercial companies provide useful updates in their development of DUV emitters, including Nichia (Fujioka et al ), Nitride Semiconductors (Muramoto et al ) and Sensor Electronic Technology (Shatalov et al ). We believe these articles will provide an excellent overview of the state of technology. The growth of AlGaN heterostructures by molecular beam epitaxy, in contrast to the common organo-metallic vapour phase epitaxy, is discussed by Ivanov et al. Since hexagonal boron nitride (BN) has received much attention as both a UV and a two-dimensional electronic material, we believe it serves readers well to include the

  20. Lunar deep drill apparatus

    NASA Technical Reports Server (NTRS)

    1989-01-01

    Proposed as a baseline configuration, this rotary drill apparatus is designed to produce 100-mm diameter holes in the lunar surface at depths up to 50 meters. The drill is intended to acquire samples for scientific analysis, mineral resource location, calibration of electronic exploration devices, and foundation analysis at construction sites. It is also intended to prepare holes for emplacement of scientific instruments, the setting of structural anchors, and explosive methods in excavation and mining activities. Defined as a deep drill because of the modular drill string, it incorporates an automatic rod changer. The apparatus is teleoperated from a remote location, such as earth, utilizing supervisory control techniques. It is thus suitable for unmanned and man-tended operation. Proven terrestrial drilling technology is used to the extent it is compatible with the lunar environment. Augers and drive tubes form holes in the regolith and may be used to acquire loose samples. An inertial cutting removal system operates intermittently while rock core drilling is in progress. The apparatus is carried to the work site by a three-legged mobile platform which also provides a 2-meter feed along the hole centerline, an off-hole movement of approximately .5 meters, an angular alignment of up to 20 deg. from gravity vertical, and other dexterity required in handling rods and samples. The technology can also be applied using other carriers which incorporate similar motion capabilities. The apparatus also includes storage racks for augers, rods, and ancillary devices such as the foot-plate that holds the down-hole tooling during rod changing operations.

  1. The Deep Space Network, volume 17

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The objectives, functions, and organization of the Deep Space Network are summarized. The Deep Space Instrumentation Facility, the Ground Communications Facility, and the Network Control System are described.

  2. Apparent phosphorus availabilities of selected traditional and alternative feedstuffs for channel catfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A digestibility trial with channel catfish Ictalurus punctatus was conducted to determine apparent availability coefficients (AACs) of phosphorus for selected common feedstuffs: soybean meal, cottonseed meal, wheat middlings, corn gluten feed (CGF), and corn distillers dried grains with solubles (DD...

  3. Apparent size contrasts of retinal images and size constancy as determinants of the moon illusion.

    PubMed

    Smith, O W; Smith, P C; Geist, C C; Zimmermann, R R

    1978-06-01

    Kaufman and Rock (1962) and Rock and Kaufman (1962) concluded that the moon illusion is a function of and attributable to apparent distance. They also reported a large framing effect as an exception. Analysis of the effect suggests two components which can account for the illusion independently of apparent distance. These are apparent size contrasts of visual images of discriminable features or objects of the earth with the moon's image and size constancy of the features or objects plus the interactions of the two. Apparent distances to horizons are always a consequence of the necessary conditions for the illusion. They are related to the illusion but are not a determinant of it. PMID:673635

  4. The apparent fine-tuning of the cosmological, gravitational and fine structure constants

    NASA Astrophysics Data System (ADS)

    Eaves, Laurence

    2016-02-01

    A numerical coincidence relating the values of the cosmological, gravitational and electromagnetic fine structure constants is presented and discussed in relation to the apparent anthropic fine-tuning of these three fundamental constants of nature.

  5. Deep Space 1 (fact sheet)

    NASA Technical Reports Server (NTRS)

    Fisher, D. K.

    1998-01-01

    Exerting less force than does a single sheet of paper resting in your hand, Deep Space 1's ion propulsion system will slowly, yet continuously accelerate the spacecraft well beyond speeds attainable by conventional chemical propulsion.

  6. Deep Space Telecommunications Systems Engineering

    NASA Technical Reports Server (NTRS)

    Yuen, J. H. (Editor)

    1982-01-01

    Descriptive and analytical information useful for the optimal design, specification, and performance evaluation of deep space telecommunications systems is presented. Telemetry, tracking, and command systems, receiver design, spacecraft antennas, frequency selection, interference, and modulation techniques are addressed.

  7. [TO CURE THE APPARENTLY DEAD. NOSOLOGY AND MEDICAL RESUSCITATION IN ITALY(XVIII CENT.)].

    PubMed

    Marinozzi, Silvia

    2015-01-01

    The first specific techniques and triages for medical resuscitation developed in the XVIII century, specifically to rescue the drowned persons. The topic of resuscitation in strictly connected to the theme of the apparent death, to the dread of the "buried alive", to the progress of forensic medicine and to the administrative and legislative policies. The contribute aims to focus on the contribution of the medical and pathologic nosology about the conception of the apparent death, read as asphyxia. PMID:26946822

  8. Goldstone Deep Space Communication Complex

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Three 34m (110 ft.) diameter Beam Waveguide antennas located at the Goldstone Deep Space Communications Complex, situated in the Mojave Desert in California. This is one of three complexes which comprise NASA's Deep Space Network (DSN). The DSN provides radio communications for all of NASA's interplanetary spacecraft and is also utilized for radio astronomy and radar observations of the solar system and the universe.

  9. Deep Percolation in Devegetated Hillslopes

    NASA Astrophysics Data System (ADS)

    Ebel, B. A.; Hinckley, E. S.

    2011-12-01

    Deep percolation has recently been recognized as a critical component in hillslope hydrology studies. In devegetated hillslopes where vegetation is killed and, in some cases, removed, deep percolation may be substantially enhanced beyond pre-disturbance magnitudes. We discuss two examples of devegetated hillslopes where water balance partitioning shifted to favor increased deep percolation fluxes for some hydrologic conditions. The first is the Coos Bay Experimental Catchment in Oregon, USA, where commercial forestry resulted in the complete removal of trees. An intensive field campaign in the 1990's resulted in a long term record of precipitation, discharge, piezometric response, and groundwater levels. Hydrologic response modeling confirms hypotheses from the field-data analysis and points to unresolved questions regarding feedbacks between deep percolation and near-surface hydrologic processes. The second example is the area burned by the Fourmile Canyon Fire in Colorado, USA, where a severe wildland fire removed all vegetation from a north-aspect hillslope in 2010. Precipitation, atmospheric conditions, soil-water content, matric potential, and runoff have been measured since the fire devegetated the site. Subsurface sampling of the vadose zone is accomplished using suction lysimeters to capture total nitrate, ammonium, and dissolved organic carbon concentrations. Darcian flux calculations of net infiltration from the shallow soil into fractured granodiorite bedrock are used to estimate solute fluxes to a deeper groundwater system. Virtual experiments using numerical models of unsaturated fluid flow and solute transport further elucidate the temporal dynamics of deep percolation and associated solute fluxes during spring snowmelt and frontal rainstorms, which are the major hydrologic drivers of deep percolation in this fire-impacted system. Together, these examples serve to illustrate the critical importance of deep percolation in disturbed landscapes. The

  10. Distinguishing among major controls on the apparent thermal and barometric structure of metamorphic belts

    SciTech Connect

    Day, H.W.

    1985-01-01

    The apparent thermal and barometric structures of metamorphosed terrains are expressed in the map patterns of isograds and bathograds. Geographic variation in the apparent P,T of peak metamorphism may be the result of: (1) differences in the amount of tectonic thickening (2) variation in the thermal properties of the lithosphere or (3) differential uplift across the mountain belt. Oversimplified tectonic models of a burial and uplift event, combined with simple physical models for the conductive transfer of heat, have normally been used. The results suggest that the relative roles of the three large scale controls on metamorphism may be distinguished. In mountain belts having variable tectonic thickening, apparent isotherms and isobars of peak metamorphism are parallel. Geographic variation in either thermal properties or uplift history, by contrast, leads to patterns of intersecting apparent isobars and isotherms (e.g.. the New England Appalachians). In terrains that experienced rapid and differential uplift, the most rapidly uplifted portions show the shortest cooling times, the least discordance between apparent mineral ages, and the lowest pressures at peak metamorphism and no necessary correlation between metamorphic grade and cooling time (e.g.. the Alps). In contrast, in terrains with large variations in either thermal parameters or tectonic thickening, long cooling times are directly associated with the highest metamorphic temperatures and the least discordance between apparent mineral ages (e.g.. the Scottish Highlands).

  11. Challenges for Deep Vadose Zone Remediation at the Hanford Site

    SciTech Connect

    Morse, J.G.; Charboneau, B.L.; Lober, R.W.; Triplett, M.B.

    2008-07-01

    The 'deep vadose zone' is defined as the region below the practical depth of surface remedy influence (e.g., excavation or barrier). At the Hanford Site, this region of the Central Plateau poses unique challenges for characterization and remediation. Currently, deep vadose zone characterization efforts and remedy selection are spread over multiple waste site Operable Units and tank farm Waste Management Areas. A particular challenge for this effort is the situation in which past leaks from single-shell tanks have become commingled with discharges from nearby liquid disposal sites. In addition, tests of potentially viable remediation technologies will be initiated in the next few years. The Hanford Site is working with all affected parties, including the Washington State Department of Ecology, the Environmental Protection Agency, DOE-RL, DOE-ORP, and multiple contractor organizations to develop remediation approaches. This effort addresses the complex and challenging technical and is evaluating the best strategy or combination of strategies for focusing technical investigations, including treatability studies to facilitate deep vadose zone remediation at the Hanford Site. In summary: Hanford's two DOE offices, Richland Operations and the Office of River Protection, are engaging the Site's regulators, EPA and the Washington State Department of Ecology, in a collaborative process to resolve one of Hanford's most challenging technical issues - investigation and remedy selection for the deep vadose zone. While this process has not reached its conclusion, several important findings are apparent. All parties agree that the current approach of addressing this problem is not likely to be successful and an alternative is needed. An essential initial step is to develop and then implement a deep vadose zone treatability test plan that logically organizes the testing of candidate technologies for application to the variety of Hanford's deep vadose zone problems. This plan is

  12. Comparison of the apparent masses and cross-axis apparent masses of seated humans exposed to single- and dual-axis whole-body vibration

    NASA Astrophysics Data System (ADS)

    Mansfield, Neil J.; Maeda, Setsuo

    2006-12-01

    Humans are exposed to whole-body vibration in many types of environment. In almost all cases, the vibration to which the human is exposed comprises multi-axis vibration, such that vibration occurs in all directions simultaneously. Despite the complex nature of vibration to which humans are exposed in the workplace, almost all laboratory studies investigating the biomechanical response of the person have been completed using single-axis simulators. This paper presents a study whereby 15 male subjects were exposed to single-axis whole-body vibration in the x-, y- and z-directions and dual-axis vibration in the xy-, xz-, and yz-directions using a 6 degree-of-freedom vibration simulator. All vibration magnitudes were 0.4 ms -2 rms in each axis. Acceleration and force was measured in the x-, y-, and z-direction during all trials. Subjects sat in two postures ('back-on' and 'back-off') on a flat rigid seat. Apparent masses measured using single-axis and dual-axis vibration stimuli showed comparable results; similarly, cross-axis apparent masses (i.e. the ratio of the force in one direction to the acceleration in another direction) were almost identical for the single- and dual-axis vibration stimuli. All results were in agreement with data previously published using single-axis vibration. In most cases, the peaks in the apparent mass and the cross-axis apparent mass occurred at a slightly lower frequency for the dual-axis vibration than for the single-axis vibration. It is hypothesised that this change is due to a nonlinear effect, analogous to that which occurs with increasing vibration magnitude for single-axis vibration.

  13. Holocene Deep Ocean Variability Detected with Individual Benthic Foraminifera

    NASA Astrophysics Data System (ADS)

    Bova, S. C.; Herbert, T.; Fox-Kemper, B.

    2015-12-01

    Historical observations of deep ocean temperatures (>700 m water depth) show apparently unprecedented rates of warming over the past half century that parallel observed surface warming, on the order of 0.1°C/decade (Purkey and Johnson 2010). Most water masses below 700 m depth, however, have not been at the sea surface where they exchange heat and carbon with the atmosphere since well before industrialization (Gebbie and Huybers 2012). How then has the heat content of isolated deep water masses responded to climate change over the last century? In models, wave mechanisms propagate thermocline anomalies quickly (Masuda et al. 2010), but these dynamics are not fully understood. We therefore turn to the sedimentary record to constrain the bounds of earlier variability from Holocene anomalies. The oxygen isotopic composition (δ18O) of individual benthic foraminifera provide approximately month-long snapshots of the temperature and salinity of ambient deep water during calcification. We exploit the short lifespan of these organisms to reconstruct variability in δ18Oshell, and thus the variability in deep water temperature and salinity, during five 200-yr Holocene intervals at 1000 m water depth in the Eastern Equatorial Pacific (EEP). Modern variability in benthic foraminifer δ18O was too weak to detect but variability at 1000 m water depth in the EEP exceeded our detection limit during two Holocene intervals at high confidence (p<0.01), with δ18O anomalies up to ~0.6 ± 0.15‰ that persist for a month or longer. Although the source of these anomalies remains speculative, rapid communication between the surface and deep ocean that operates on human timescales, faster than previously recognized, or intrinsic variability that has not been active during the history of ocean observations are potential explanations. Further work combining models and high-resolution proxy data is needed to identify the mechanism and global extent of this type of subsurface variability

  14. Ecosystem function and services provided by the deep sea

    NASA Astrophysics Data System (ADS)

    Thurber, A. R.; Sweetman, A. K.; Narayanaswamy, B. E.; Jones, D. O. B.; Ingels, J.; Hansman, R. L.

    2013-11-01

    The deep sea is often viewed as a vast, dark, remote, and inhospitable environment, yet the deep ocean and seafloor are crucial to our lives through the services and provisions that they provide. Our understanding of how the deep sea functions remains limited, but when treated synoptically, a diversity of provisioning, regulating and cultural services become apparent. The biological pump transports carbon from the atmosphere into deep-ocean water masses which are separated over prolonged periods, reducing the impact of anthropogenic carbon release. Microbial oxidation of methane keeps another potent greenhouse gas out of the atmosphere while trapping carbon in authigenic carbonates. Nutrient regeneration by all faunal size classes provides the elements necessary to fuel surface productivity and fisheries, and microbial processes detoxify a diversity of compounds. Each of these processes occur on a very small scale, yet considering the vast area over which they occur they become important for the global functioning of the ocean. The deep sea also provides a diversity of resources, including fish stocks, enormous bioprospecting potential, and elements and energy reserves that are currently being extracted and will be increasingly important in the near future. Society benefits from the intrigue and mystery, the strange life forms, and the great unknown which has acted as a muse for inspiration and imagination since near the beginning of civilization. While many functions occur on the scale of microns to meters and time scales up to years, the derived services that result are only useful after centuries of integrated activity. This vast dark habitat, that covers the majority of the globe, harbors processes that directly impact humans in a diversity of ways, however the same traits that differentiate it from terrestrial or shallow marine systems also result in a greater need for integrated spatial and temporal understanding as it experiences increased use by society.

  15. Near Infrared Imaging of the Hubble Deep Field with Keck Telescope

    NASA Technical Reports Server (NTRS)

    Hogg, David W.; Neugebauer, G.; Armus, Lee; Matthews, K.; Pahre, Michael A.; Soifer, B. T.; Weinberger, A. J.

    1997-01-01

    Two deep K-band (2.2 micrometer) images, with point-source detection limits of K=25.2 mag (one sigma), taken with the Keck Telescope in subfields of the Hubble Deep Field, are presented and analyzed. A sample of objects to K=24 mag is constructed and V(sub 606)- I(sub 814) and I(sub 814)-K colors are measured. By stacking visually selected objects, mean I(sub 814)-K colors can be measured to very faint levels, the mean I(sub 814)-K color is constant with apparent magnitude down to V(sub 606)=28 mag.

  16. FORT UNION DEEP

    SciTech Connect

    Lyle A. Johnson Jr.

    2002-09-01

    Coalbed methane (CBM) is currently the hottest area of energy development in the Rocky Mountain area. The Powder River Basin (PRB) is the largest CBM area in Wyoming and has attracted the majority of the attention because of its high permeability and relatively shallow depth. Other Wyoming coal regions are also being targeted for development, but most of these areas have lower permeability and deeper coal seams. This project consists of the development of a CBM stimulation system for deep coal resources and involves three work areas: (1) Well Placement, (2) Well Stimulation, and (3) Production Monitoring and Evaluation. The focus of this project is the Washakie Basin. Timberline Energy, Inc., the cosponsor, has a project area in southern Carbon County, Wyoming, and northern Moffat County, Colorado. The target coal is found near the top of the lower Fort Union formation. The well for this project, Evans No.1, was drilled to a depth of 2,700 ft. Three coal seams were encountered with sandstone and some interbedded shale between seams. Well logs indicated that the coal seams and the sandstone contained gas. For the testing, the upper seam at 2,000 ft was selected. The well, drilled and completed for this project, produced very little water and only occasional burps of methane. To enhance the well, a mild severity fracture was conducted to fracture the coal seam and not the adjacent sandstone. Fracturing data indicated a fracture half-length of 34 ft, a coal permeability of 0.2226 md, and permeability of 15.3 md. Following fracturing, the gas production rate stabilized at 10 Mscf/day within water production of 18 bpd. The Western Research Institute (WRI) CBM model was used to design a 14-day stimulation cycle followed by a 30-day production period. A maximum injection pressure of 1,200 psig to remain well below the fracture pressure was selected. Model predictions were 20 Mscf/day of air injection for 14 days, a one-day shut-in, then flowback. The predicted flowback

  17. FORT UNION DEEP

    SciTech Connect

    Lyle A. Johnson Jr.

    2002-03-01

    Coalbed methane (CBM) is currently the hottest area of energy development in the Rocky Mountain area. The Powder River Basin (PRB) is the largest CBM area in Wyoming and has attracted the majority of the attention because of its high permeability and relatively shallow depth. Other Wyoming coal regions are also being targeted for development, but most of these areas have lower permeability and deeper coal seams. This project consists of the development of a CBM stimulation system for deep coal resources and involves three work areas: (1) Well Placement, (2) Well Stimulation, and (3) Production Monitoring and Evaluation. The focus of this project is the Washakie Basin. Timberline Energy, Inc., the cosponsor, has a project area in southern Carbon County, Wyoming, and northern Moffat County, Colorado. The target coal is found near the top of the lower Fort Union formation. The well for this project, Evans No.1, was drilled to a depth of 2,700 ft. Three coal seams were encountered with sandstone and some interbedded shale between seams. Well logs indicated that the coal seams and the sandstone contained gas. For the testing, the upper seam at 2,000 ft was selected. The well, drilled and completed for this project, produced very little water and only occasional burps of methane. To enhance the well, a mild severity fracture was conducted to fracture the coal seam and not the adjacent sandstone. Fracturing data indicated a fracture half-length of 34 ft, a coal permeability of 0.2226 md, and permeability of 15.3 md. Following fracturing, the gas production rate stabilized at 10 Mscf/day within water production of 18 bpd. The Western Research Institute (WRI) CBM model was used to design a 14-day stimulation cycle followed by a 30-day production period. A maximum injection pressure of 1,200 psig to remain well below the fracture pressure was selected. Model predictions were 20 Mscf/day of air injection for 14 days, a one-day shut-in, then flowback. The predicted flowback

  18. Making sense of deep sequencing.

    PubMed

    Goldman, D; Domschke, K

    2014-10-01

    This review, the first of an occasional series, tries to make sense of the concepts and uses of deep sequencing of polynucleic acids (DNA and RNA). Deep sequencing, synonymous with next-generation sequencing, high-throughput sequencing and massively parallel sequencing, includes whole genome sequencing but is more often and diversely applied to specific parts of the genome captured in different ways, for example the highly expressed portion of the genome known as the exome and portions of the genome that are epigenetically marked either by DNA methylation, the binding of proteins including histones, or that are in different configurations and thus more or less accessible to enzymes that cleave DNA. Deep sequencing of RNA (RNASeq) reverse-transcribed to complementary DNA is invaluable for measuring RNA expression and detecting changes in RNA structure. Important concepts in deep sequencing include the length and depth of sequence reads, mapping and assembly of reads, sequencing error, haplotypes, and the propensity of deep sequencing, as with other types of 'big data', to generate large numbers of errors, requiring monitoring for methodologic biases and strategies for replication and validation. Deep sequencing yields a unique genetic fingerprint that can be used to identify a person, and a trove of predictors of genetic medical diseases. Deep sequencing to identify epigenetic events including changes in DNA methylation and RNA expression can reveal the history and impact of environmental exposures. Because of the power of sequencing to identify and deliver biomedically significant information about a person and their blood relatives, it creates ethical dilemmas and practical challenges in research and clinical care, for example the decision and procedures to report incidental findings that will increasingly and frequently be discovered. PMID:24925306

  19. Apparent density patterns in subchondral bone of the sloth and anteater forelimb.

    PubMed

    Patel, Biren A; Carlson, Kristian J

    2008-10-23

    Vertebrate morphologists often are interested in inferring limb-loading patterns in animals characterized by different locomotor repertoires. Because bone apparent density (i.e. mass per unit volume of bone inclusive of porosities) is a determinant of compressive strength, and thus indicative of compressive loading, recent comparative studies in primates have proposed a structure-function relationship between apparent density of subchondral bone and locomotor behaviours that vary in compressive loading. If such patterns are found in other mammals, then these relationships would be strengthened further. Here, we examine the distal radius of suspensory sloths that generally load their forelimbs (FLs) in tension and of quadrupedal anteaters that generally load their FLs in compression. Computed tomography osteoabsorptiometry was used to visualize the patterns in subchondral apparent density. Suspensory sloths exhibit relatively smaller areas of high apparent density than quadrupedal anteaters. This locomotor-based pattern is analogous to the pattern observed in suspensory and quadrupedal primates. Similarity between xenarthran and primate trends suggests broad-scale applicability for analysing subchondral bone apparent density and supports the idea that bone functionally alters its material properties in response to locomotor behaviours. PMID:18628113

  20. A general approach for DC apparent resistivity evaluation on arbitrarily shaped 3D structures

    NASA Astrophysics Data System (ADS)

    Marescot, Laurent; Rigobert, Stéphane; Palma Lopes, Sérgio; Lagabrielle, Richard; Chapellier, Dominique

    2006-09-01

    This paper presents a general and comprehensive way to evaluate the geometric factors used for the computation of apparent resistivities in the context of DC resistivity mapping and non-destructive investigations, in laboratory or in the field. This technique enables one to consider 3-dimensional objects with arbitrary shape. The expression of the geometric factor results from the early definition of apparent resistivitiy. It is expressed as the ratio of the resistances obtained from measurements to the resistances induced in the medium with unitary resistivity considering the same object geometry and electrode set-up. In this work, a finite element code is used for the computation of the geometric factor. In this code, the electrodes do not need to be located on the nodes of the mesh. This option makes the finite element mesh generation task easier. A first synthetical example illustrates how the present approach could be applied to apparent resistivity mapping in an environment with a complex underground topography. A second example, based on real data in a water tank, illustrates the simulation of a resistivity survey on a structure with finite extent, e.g. a laboratory sample. In both examples, topographic artefacts and effects of material sample shapes are successfully taken into account and reliable apparent resistivity descriptions of the structures are obtained. The effectiveness of the method for the detection of heterogeneities in apparent resistivity maps is highlighted.

  1. The apparent strain stability and repeatability of a BCL3 resistance strain gage

    NASA Astrophysics Data System (ADS)

    Lei, Jih-Fen

    1991-02-01

    Experiments were conducted at NASA-Lewis to study the effect of microstructural instability on the apparent strain stability and reproducibility of a BCL3 resistance strain gage. The resistance drift of the gage at various temperatures in the phase transition temperature range (PTTR) was measured. The effects of the heating and cooling rates with which the gage passed through the PTTR on the apparent strain characteristics of the gage were also studied. BCL3 gage, like other Fe-Cr-Al based gages, exhibited apparent strain instability in the temperature range of 700 to 1100 F due to the reversible microstructural transition the gage materials experienced in this temperature range. The BCL3 gage had a maximum apparent strain drift in the neighborhood of 770 F with an average drift rate of approx. -440 microstrain/hr in 2 hrs. The use of the BCL3 gage as well as other Fe-Cl-Al based gages for static strain measurements within the PTTR should be avoided unless the time durations in the PTTR are small enough to introduce a neglible drift. The microstructure transition that the BCL3 gage underwent occurred in the temperature range of 750 to 1050 F during heating and around 1000 to 800 F during cooling. The heating rate, and, in particular, the cooling rate with which the gage passed through the PTTR affected the shape and the repeatability of the apparent strain curve of the gage.

  2. The representation of moving 3-D objects in apparent motion perception.

    PubMed

    Hidaka, Souta; Kawachi, Yousuke; Gyoba, Jiro

    2009-08-01

    In the present research, we investigated the depth information contained in the representations of apparently moving 3-D objects. By conducting three experiments, we measured the magnitude of representational momentum (RM) as an index of the consistency of an object's representation. Experiment 1A revealed that RM magnitude was greater when shaded, convex, apparently moving objects shifted to a flat circle than when they shifted to a shaded, concave, hemisphere. The difference diminished when the apparently moving objects were concave hemispheres (Experiment 1B). Using luminance-polarized circles, Experiment 2 confirmed that these results were not due to the luminance information of shading. Experiment 3 demonstrated that RM magnitude was greater when convex apparently moving objects shifted to particular blurred convex hemispheres with low-pass filtering than when they shifted to concave hemispheres. These results suggest that the internal object's representation in apparent motion contains incomplete depth information intermediate between that of 2-D and 3-D objects, particularly with regard to convexity information with low-spatial-frequency components. PMID:19633345

  3. Apparent plasticity in functional traits determining competitive ability and spatial distribution: a case from desert

    PubMed Central

    Xie, Jiang-Bo; Xu, Gui-Qing; Jenerette, G. Darrel; Bai, Yong-fei; Wang, Zhong-Yuan; Li, Yan

    2015-01-01

    Species competitive abilities and their distributions are closely related to functional traits such as biomass allocation patterns. When we consider how nutrient supply affects competitive abilities, quantifying the apparent and true plasticity in functional traits is important because the allometric relationships among traits are universal in plants. We propose to integrate the notion of allometry and the classical reaction norm into a composite theoretical framework that quantifies the apparent and true plasticity. Combining the framework with a meta-analysis, a series of field surveys and a competition experiment, we aimed to determine the causes of the dune/interdune distribution patterns of two Haloxylon species in the Gurbantonggut Desert. We found that (1) the biomass allocation patterns of both Haloxylon species in responses to environmental conditions were apparent rather than true plasticity and (2) the allometric allocation patterns affected the plants’ competition for soil nutrient supply. A key implication of our results is that the apparent plasticity in functional traits of plants determines their response to environmental change. Without identifying the apparent and true plasticity, we would substantially overestimate the magnitude, duration and even the direction of plant responses in functional traits to climate change. PMID:26190745

  4. Colletotrichum gloeosporioides sensu lato causing deep soft tissue mycosis following a penetrating injury

    PubMed Central

    Figtree, Melanie; Weeks, Kerry; Chan, Leonie; Leyton, Arda; Bowes, Andrew; Giuffre, Bruno; Sullivan, Martin; Hudson, Bernard J

    2013-01-01

    Colletotrichum species have been rarely implicated in human disease. We describe a case of deep soft tissue mycosis following a penetrating injury with a lemon tree thorn. Direct Blankophor BA (Bayer) stain from intraoperative tissue showed fungal elements. Pure growth fungus was apparent at 2–4 days. Morphological features provisionally identified the isolate as a coelomycetous fungus, likely Colletotrichum species. This was confirmed with molecular analysis of the internal transcribed spacer region (ITS) region. PMID:24432213

  5. Relationships between deep-sea tunicate populations west and east of the Straits of Gibraltar

    NASA Astrophysics Data System (ADS)

    Monniot, Claude; Monniot, Françoise

    Twenty-four species of tunicates were collected from deep bottoms on each side of the Gibraltar sill, in the adjacent Mediterranean Sea and Atlantic Ocean. In the Atlantic, stations bathed by Atlantic and Mediterranean waters were both sampled. No transport of ascidian taxa by the outflow of Mediterranean water into the Atlantic is apparent. The alternative hypothesis of an Atlantic origin of bathyal ascidian species in the Mediterranean Sea is proposed.

  6. Glassy Objects (Microtektites?) from Deep-Sea Sediments near the Ivory Coast.

    PubMed

    Glass, B P

    1968-08-30

    Glassy objects of spherical, oval, dumbbell, teardrop, and irregular shapes have been found in a deep-sea sediment core taken off the Ivory Coast. They occur in a layer of sediment that was apparently deposited about 800,000 years ago. Their geographic location, appearance, and physical properties suggest that they are microtektites and that they are related to the tektite-strewn field of the Ivory Coast. PMID:17812117

  7. Evaporation, viscous flow, and electrostatic interaction of charged interfaces in the apparent contact line region

    NASA Astrophysics Data System (ADS)

    Ketelaar, Christiaan; Ajaev, Vladimir S.

    2015-11-01

    We consider evaporation of an aqueous solution near an apparent contact line separating a macroscopically dry area of a heated solid substrate and a constant-curvature meniscus far away from the substrate. Viscous flow, described by a lubrication-type model, is coupled to the interaction of electrical double layers formed near the solid-liquid and liquid-vapor interfaces. The electrostatic interaction is described using the nonlinear Poisson-Boltzmann equation and is shown to affect both normal and shear stress balances at the deformable interface. For steady configurations, we find that the apparent contact line region becomes wider and the total evaporation rate there increases as the substrate potential is increased. Motion of the apparent contact line in response to changes in the substrate temperature is also investigated. The contact line speed is found to increase when the electrostatic effects are incorporated into the model.

  8. Apparent Multi-Decadal Trend in Shortwave Cloud Forcing Over the Tropical Pacific

    SciTech Connect

    Somerville, R C J; Potter, G L; Kanamitsu, M; Hnilo, J J; Woolen, J

    2000-10-03

    The NCEP/NCAR reanalysis (Kalnay et al. 1996) of atmospheric data beginning in 1948 has provided an opportunity to study a consistent half-century record of assimilated weather observations. Through the examination of several fields, we find an apparent long-term decrease in relative humidity, and hence a decrease in inferred cloud amount, in a large region in the central tropical Pacific. As a result, the apparent short-wave cloud radiative forcing in that region decreased by nearly 15 Wm{sup -2} Over the duration of the period. Two major questions arise from these preliminary results. The first question involves the extent to which the apparent trend over the 50-year period is a real phenomenon rather than an artifact, either of the reanalysis methodology or of observing system evolution. The second question is, if the phenomenon is not entirely an artifact, but is at least partially real, what is its cause?

  9. A Self-Alignment Algorithm for SINS Based on Gravitational Apparent Motion and Sensor Data Denoising

    PubMed Central

    Liu, Yiting; Xu, Xiaosu; Liu, Xixiang; Yao, Yiqing; Wu, Liang; Sun, Jin

    2015-01-01

    Initial alignment is always a key topic and difficult to achieve in an inertial navigation system (INS). In this paper a novel self-initial alignment algorithm is proposed using gravitational apparent motion vectors at three different moments and vector-operation. Simulation and analysis showed that this method easily suffers from the random noise contained in accelerometer measurements which are used to construct apparent motion directly. Aiming to resolve this problem, an online sensor data denoising method based on a Kalman filter is proposed and a novel reconstruction method for apparent motion is designed to avoid the collinearity among vectors participating in the alignment solution. Simulation, turntable tests and vehicle tests indicate that the proposed alignment algorithm can fulfill initial alignment of strapdown INS (SINS) under both static and swinging conditions. The accuracy can either reach or approach the theoretical values determined by sensor precision under static or swinging conditions. PMID:25923932

  10. The origin of the biomechanical bias in apparent body movement perception.

    PubMed

    Vannuscorps, Gilles; Caramazza, Alfonso

    2016-08-01

    The perception of apparent body movement sometimes follows biologically plausible paths rather than paths along the shortest distance as in the case for inanimate objects. For numerous authors, this demonstrates that the somatosensory and motor representations of the observer's own body support and constrain the perception of others' body movements. In this paper, we report evidence that calls for a re-examination of this account. We presented an apparent upper limb movement perception task to typically developed participants and five individuals born without upper limbs who were, therefore, totally deprived of somatosensory or motor representations of those limbs. Like the typically developed participants, they showed the typical bias toward long and biomechanically plausible path. This finding suggests that the computations underlying the biomechanical bias in apparent body movement perception is intrinsic to the visual system. PMID:27238946

  11. A Self-Alignment Algorithm for SINS Based on Gravitational Apparent Motion and Sensor Data Denoising.

    PubMed

    Liu, Yiting; Xu, Xiaosu; Liu, Xixiang; Yao, Yiqing; Wu, Liang; Sun, Jin

    2015-01-01

    Initial alignment is always a key topic and difficult to achieve in an inertial navigation system (INS). In this paper a novel self-initial alignment algorithm is proposed using gravitational apparent motion vectors at three different moments and vector-operation. Simulation and analysis showed that this method easily suffers from the random noise contained in accelerometer measurements which are used to construct apparent motion directly. Aiming to resolve this problem, an online sensor data denoising method based on a Kalman filter is proposed and a novel reconstruction method for apparent motion is designed to avoid the collinearity among vectors participating in the alignment solution. Simulation, turntable tests and vehicle tests indicate that the proposed alignment algorithm can fulfill initial alignment of strapdown INS (SINS) under both static and swinging conditions. The accuracy can either reach or approach the theoretical values determined by sensor precision under static or swinging conditions. PMID:25923932

  12. Apparent spatial blurring and displacement of a point optical source due to cloud scattering

    SciTech Connect

    Brower, K.L.

    1997-09-01

    A Monte Carlo algorithm is used to determine the apparent spatial blurring of a terrestrial 1.07 micron optical point source due to cloud scattering as seen from space. The virtual image of a point source over a virtual source plane area 22.4 x 22.4 square kilometers arising from cloud scattering was determined for stratus clouds (NASA cloud number 5) and altostratus clouds optical source arises from photon scattering by cloud water droplets. Displacement of the virtual source is due to the apparent illumination of the cloud top region directly about the actual source which when viewed at a nonzero look angle gives a projected displacement of the apparent source relative to the actual source. These features are quantified by an analysis of the Monte Carlo computational results.

  13. Apparent competition and native consumers exacerbate the strong competitive effect of an exotic plant species.

    PubMed

    Orrock, John L; Dutra, Humberto P; Marquis, Robert J; Barber, Nicholas

    2015-04-01

    Direct and indirect effects can play a key role in invasions, but experiments evaluating both are rare. We examined the roles of direct competition and apparent competition by exotic Amur honeysuckle (Lonicera maackii) by manipulating (1) L. maackii vegetation, (2) presence of L. maackii fruits, and (3) access to plants by small mammals and deer. Direct competition with L. maackii reduced the abundance and richness of native and exotic species, and native consumers significantly reduced the abundance and richness of native species. Although effects of direct competition and consumption were more pervasive, richness of native plants was also reduced through apparent competition, as small-mammal consumers reduced richness only when L. maackii fruits were present. Our experiment reveals the multiple, interactive pathways that affect the success and impact of an invasive exotic plant: exotic plants may directly benefit from reduced attack by native consumers, may directly exert strong competitive effects on native plants, and may also benefit from apparent competition. PMID:26230025

  14. Effects of Red Blood Cell Aggregation on the Apparent Viscosity of Blood Flow in Tubes.

    NASA Astrophysics Data System (ADS)

    Hitt, Darren L.; Lowe, Mary L.

    1996-11-01

    In arterioles and venules (20-200μ diameter), the low shear rates enable red blood cells to form aggregate structures of varying sizes and morphology. The size and distribution of the aggregates affect the flow impedance within a microvascular network; this effect may be characterized by an "apparent viscosity". In this study, we measure the apparent viscosity of blood flow in 50μ glass tubes as a function of shear rate and red blood cell volume fraction (hematocrit); for a fixed tube geometry and an imposed flow rate, the viscosity is determined by measuring the pressure drop across the tube. To correlate the apparent viscosity with the size and spatial distribution of the aggregates in the flow, video images of the flow are recorded and analyzed using power spectral techniques. Pig blood and sheep blood are used as the models for aggregating and non-aggregating blood, respectively. Supported by NSF PFF Award CTS-9253633

  15. Cosmopolitanism and Biogeography of the Genus Manganonema (Nematoda: Monhysterida) in the Deep Sea

    PubMed Central

    Zeppilli, Daniela; Vanreusel, Ann; Danovaro, Roberto

    2011-01-01

    Simple Summary The deep sea comprises more than 60% of the Earth surface, and likely represents the largest reservoir of as yet undiscovered biodiversity. Nematodes are the most abundant taxon on Earth and are particularly abundant and diverse in the deep sea. Nevertheless, knowledge of their biogeography especially in the deep sea is still at its infancy. This article explores the distribution of the genus Manganonema in the deep Atlantic Ocean and Mediterranean Sea providing new insights about this apparently rare deep-sea genus. Abstract Spatial patterns of species diversity provide information about the mechanisms that regulate biodiversity and are important for setting conservation priorities. Present knowledge of the biogeography of meiofauna in the deep sea is scarce. This investigation focuses on the distribution of the deep-sea nematode genus Manganonema, which is typically extremely rare in deep-sea sediment samples. Forty-four specimens of eight different species of this genus were recorded from different Atlantic and Mediterranean regions. Four out of the eight species encountered are new to science. We report here that this genus is widespread both in the Atlantic and in the Mediterranean Sea. These new findings together with literature information indicate that Manganonema is a cosmopolitan genus, inhabiting a variety of deep-sea habitats and oceans. Manganonema shows the highest diversity at water depths >4,000 m. Our data, therefore, indicate that this is preferentially an abyssal genus that is able, at the same time, to colonize specific habitats at depths shallower than 1,000 m. The analysis of the distribution of the genus Manganonema indicates the presence of large differences in dispersal strategies among different species, ranging from locally endemic to cosmopolitan. Lacking meroplanktonic larvae and having limited dispersal ability due to their small size, it has been hypothesized that nematodes have limited dispersal potential. However, the

  16. Mixing effects on apparent reaction rates and isotope fractionation during denitrification in a heterogeneous aquifer

    USGS Publications Warehouse

    Green, C.T.; Böhlke, J.K.; Bekins, B.A.; Phillips, S.P.

    2010-01-01

    Gradients in contaminant concentrations and isotopic compositions commonly are used to derive reaction parameters for natural attenuation in aquifers. Differences between field-scale (apparent) estimated reaction rates and isotopic fractionations and local-scale (intrinsic) effects are poorly understood for complex natural systems. For a heterogeneous alluvial fan aquifer, numerical models and field observations were used to study the effects of physical heterogeneity on reaction parameter estimates. Field measurements included major ions, age tracers, stable isotopes, and dissolved gases. Parameters were estimated for the O2 reduction rate, denitrification rate, O 2 threshold for denitrification, and stable N isotope fractionation during denitrification. For multiple geostatistical realizations of the aquifer, inverse modeling was used to establish reactive transport simulations that were consistent with field observations and served as a basis for numerical experiments to compare sample-based estimates of "apparent" parameters with "true" (intrinsic) values. For this aquifer, non-Gaussian dispersion reduced the magnitudes of apparent reaction rates and isotope fractionations to a greater extent than Gaussian mixing alone. Apparent and true rate constants and fractionation parameters can differ by an order of magnitude or more, especially for samples subject to slow transport, long travel times, or rapid reactions. The effect of mixing on apparent N isotope fractionation potentially explains differences between previous laboratory and field estimates. Similarly, predicted effects on apparent O2 threshold values for denitrification are consistent with previous reports of higher values in aquifers than in the laboratory. These results show that hydrogeological complexity substantially influences the interpretation and prediction of reactive transport. ?? 2010 by the American Geophysical Union.

  17. Prefractal scaling of apparent soil moisture estimated from vertical planes of Vertisol pit images

    NASA Astrophysics Data System (ADS)

    Cumbrera, R.; Tarquis, A. M.; Gascó, G.; Millán, H.

    2012-04-01

    Image analysis could be a useful tool for investigating the spatial patterns of apparent soil moisture at multiple resolutions. The objectives of the present work were (i) to define apparent soil moisture patterns from vertical planes of Vertisol pit images and (ii) to describe the scaling of apparent soil moisture distribution using fractal parameters. Twelve soil pits (0.70 m long x 0.60 m width x 0.30 m depth) were excavated on a bare Mazic Pellic Vertisol. Six of them were excavated in April/2011 and six pits were established in May/2011 after three days of a moderate rainfall event. Digital photographs were taken from each Vertisol pit using a KodakTM digital camera. The mean image size was 1600 x 945 pixels with one physical pixel ≈ 373 μm of the photographed soil pit. Each soil image was analyzed using two prefractal scaling exponents, box counting (capacity) dimension (DBC) and interface fractal dimension (Di), and three prefractal scaling coefficients, the total number of boxes intercepting the foreground pattern at a unit scale (A), fractal lacunarity at the unit scale (Γ1) and Shannon entropy at the unit scale (S1). All prefractal scaling parameters identified significant differences between both sets of spatial patterns. Fractal lacunarity was the best discriminator between apparent soil moisture patterns. Soil image interpretation with prefractal parameters can be incorporated within site-specific agriculture toolbox. While fractal exponents condense information on space filling characteristics of the pattern, prefractal coefficients represent the investigated soil property as seen through a higher resolution microscope. In spite of some computational and practical limitations, image analysis of apparent soil moisture patterns could be used in connection with traditional soil moisture sampling, which always renders punctual estimates. Key words: Image analysis, fractal scaling, apparent soil moisture, Vertisols Acknowledgements This work has been

  18. On the expected relationships among apparent stress, static stress drop, effective shear fracture energy, and efficiency

    USGS Publications Warehouse

    Beeler, N.M.; Wong, T.-F.; Hickman, S.H.

    2003-01-01

    We consider expected relationships between apparent stress ??a and static stress drop ????s using a standard energy balance and find ??a = ????s (0.5 - ??), where ?? is stress overshoot. A simple implementation of this balance is to assume overshoot is constant; then apparent stress should vary linearly with stress drop, consistent with spectral theories (Brune, 1970) and dynamic crack models (Madariaga, 1976). Normalizing this expression by the static stress drop defines an efficiency ??sw = ??sa/????s as follows from Savage and Wood (1971). We use this measure of efficiency to analyze data from one of a number of observational studies that find apparent stress to increase with seismic moment, namely earthquakes recorded in the Cajon Pass borehole by Abercrombie (1995). Increases in apparent stress with event size could reflect an increase in seismic efficiency; however, ??sw for the Cajon earthquakes shows no such increase and is approximately constant over the entire moment range. Thus, apparent stress and stress drop co-vary, as expected from the energy balance at constant overshoot. The median value of ??sw for the Cajon earthquakes is four times lower than ??sw for laboratory events. Thus, these Cajon-recorded earthquakes have relatively low and approximately constant efficiency. As the energy balance requires ??sw = 0.5 - ??, overshoot can be estimated directly from the Savage-Wood efficiency; overshoot is positive for Cajon Pass earthquakes. Variations in apparent stress with seismic moment for these earthquakes result primarily from systematic variations in static stress drop with seismic moment and do not require a relative decrease in sliding resistance with increasing event size (dynamic weakening). Based on the comparison of field and lab determinations of the Savage-Wood efficiency, we suggest the criterion ??sw > 0.3 as a test for dynamic weakening in excess of that seen in the lab.

  19. Deep space optical communications experiment

    NASA Technical Reports Server (NTRS)

    Kinman, P.; Katz, J.; Gagliardi, R.

    1983-01-01

    An optical communications experiment between a deep space vehicle and an earth terminal is under consideration for later in this decade. The experimental link would be incoherent (direct detection) and would employ two-way cooperative pointing. The deep space optical transceiver would ride piggyback on a spacecraft with an independent scientific objective. Thus, this optical transceiver is being designed for minimum spacecraft impact - specifically, low mass and low power. The choices of laser transmitter, coding/modulation scheme, and pointing mechanization are discussed. A representative telemetry link budget is presented.

  20. Apparently persistent weakness after recurrent hypokalemic paralysis: a tale of two disorders.

    PubMed

    Ramachandiran, Nandhagopal

    2008-09-01

    A 19-year-old woman presented with recurrent hypokalemic paralysis, followed by apparently persistent symptoms due to coexisting osteomalacia. Distal renal tubular acidosis type 1 (dRTA1) linked the metabolic abnormalities and occurred as an extraglandular feature of Sjögren syndrome (SS). This case highlights the fact that in the setting of recurrent hypokalemia, apparently progressive weakness should be distinguished from primary hypokalemic paralysis and evaluated for dRTA1, as the metabolic alterations are potentially treatable. Further dRTA1 may precede the occurrence of sicca syndrome in SS. PMID:18708979