38 research outputs found

    Cultural Models, Grain-Farm Management, and Agricultural Nutrient Runoff: A Maryland Case Study of the Role of Culture in Nutrient-Management Policy

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    Government agencies responsible for monitoring the health of U.S. waterways report that nonpoint-source pollution from agricultural nutrient runoff is one of America's greatest water-quality threats. Federal agencies and states have partnered to develop nutrient-management policies and programs to reduce farm runoff. These efforts are complicated by the fact that policy decisions are made in an environment with limited resources, imperfect scientific knowledge, and diverse interests and understandings. This increases the likelihood that participants in the policy-making process will have different understandings of environmental problems and preferences for addressing them. Thus, there is a critical need for cooperation and collaboration in creating and implementing nutrient-management policies. In particular, it is important for policy makers to work collaboratively with farmers because nutrient-management policy goals cannot be achieved without their support for and full participation in policy programs. I contend that the success of nutrient-management policy efforts can be enhanced by greater knowledge of the cultural models that shape farmers' management beliefs and practices and inform their understandings of themselves and their relationship to the world. By situating policy efforts and proposals within the context of farmers' compelling cultural models, policy makers are more likely to create nutrient-management policy that farmers are willing to support and adopt. This in turn increases the likelihood that environmental goals will be achieved. A key element of this strategy is to successfully link policy ideas and practices with farmers' shared "goal-schemas" and leverage the motivational force associated with them to gain their support. To explore my contention that farmer cultural models play a central role in informing and directing their farm-management decisions, and that knowledge of these models can serve a valuable function in helping policy makers create more effective nutrient-management policies and programs, I draw on research I conducted in the Chesapeake Bay watershed with Maryland grain farmers from 1998 to 2001. The time period and focus of my research are particularly relevant to nutrient-management policy studies because they coincide with a highly contested nutrient-management policy debate in Maryland that resulted in the passage of the nation's most comprehensive environmental regulations to manage agricultural nutrient runoff

    Clinical-histopathological correlation in a case of Coats' disease

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    Background: Coats' disease is a non-hereditary ocular disease, with no systemic manifestation, first described by Coats in 1908. It occurs more commonly in children and has a clear male predominance. Most patients present clinically with unilateral decreased vision, strabismus or leukocoria. the most important differential diagnosis is unilateral retinoblastoma, which occurs in the same age group and has some overlapping clinical manifestations.Case presentation: A 4 year-old girl presented with a blind and painful right eye. Ocular examination revealed neovascular glaucoma, cataract and posterior synechiae. Although viewing of the fundus was impossible, computed tomography disclosed total exsudative retinal detachment in the affected eye. the eye was enucleated and subsequent histopathological evaluation confirmed the diagnosis of Coats' disease.Conclusion: General pathologists usually do not have the opportunity to receive and study specimens from patients with Coats' disease. Coats' disease is one of the most important differential diagnoses of retinoblastoma. Therefore, It is crucial for the pathologist to be familiar with the histopathological features of the former, and distinguish it from the latter.McGill Univ, Ctr Hlth, Dept Ophthalmol & Pathol, Montreal, PQ, CanadaHenry C Witelson Ocular Pathol Lab, Montreal, PQ, CanadaUniversidade Federal de São Paulo, EPM, Dept Ophthalmol, UNIFESP, São Paulo, BrazilHosp Servidores Estado, Dept Ophthalmol, Rio de Janeiro, BrazilUniversidade Federal de São Paulo, EPM, Dept Ophthalmol, UNIFESP, São Paulo, BrazilWeb of Scienc

    Prostate-specific membrane antigen is undetectable in choroidal neovascular membrane

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    BACKGROUND: Choroidal neovascular membrane (CNVM) is one of the leading causes of severe visual loss and is often associated with age-related macular degeneration (AMD). Various modalities of treatment, including photocoagulation and surgery, are being considered as options, but with limited success. Prostate-specific membrane antigen (PSMA) is a type II membrane glycoprotein expressed in benign and malignant prostatic tissues, in some non-prostatic tissues, and in the endothelium of tumor-associated neovasculature of non-prostatic neoplasm. Some studies have suggested that the expression of PSMA is restricted to endothelium from tumor-associated neovasculature and might be stimulated by some tumor-secreted angiogenic factors. However, no previous study demonstrating PSMA expression in non-related tumor neovasculature, such as CNVM, has been performed to date. Furthermore, demonstration of PSMA expression in CNVM in AMD patients could reveal a novel target for antineovascular therapy. The purpose of this study was to evaluate the immunohistochemical expression of PSMA in CNVM from AMD. METHODS: Immunohistochemical analysis, with a standard avidin-biotin complex technique, was performed using an anti-PSMA mouse monoclonal antibody in 30 specimens of surgically excised CNVM from AMD patients. Antibody to an endothelial cell specific marker, factor VIII, was used to confirm the location of the endothelial cells. RESULTS: The angiogenic microvessels of the 30 cases demonstrated negative staining to PSMA while factor VIII was expressed in all cases. Seventy-five percent of the secretory-acinar epithelium of the prostatic hyperplasia specimen stained positive, confirming that the immunohistochemical technique was correctly performed. CONCLUSION: The absence of PSMA expression in non-tumoral neovasculature supports the theory, previously suggested, that endothelial cell PSMA expression may be stimulated by one or more tumor-secreted angiogenic factors. Angiogenesis is very important in neoplasia and the endothelial expression of PSMA in tumor-associated neovasculature may represent a target for antineovasculature-based therapy. The absence of PSMA expression in CNVM suggests that PSMA may not be a potential target for antineovasculature-based therapy

    Imatinib mesylate alters the expression of genes related to disease progression in an animal model of uveal melanoma

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    Imatinib mesylate (IM) is a compound that inhibits both BCR-ABL tyrosine kinase and c-kit receptors. Tyrosine kinases are important in cellular signaling and mediate major cellular processes such as proliferation, differentiation, apoptosis, attachment, and migration. Twenty-six albino rabbits were injected with 1 x 10(6) human uveal melanoma (UM) cells (92.1) into the suprachoroidal space. Animals were immunosuppressed (cyclosporin A) over the course of the 12-week experiment and divided into two groups (n = 13). the experimental group received IM once daily by gavage while the control group received a placebo. One animal per group was sacrificed every week after the 2nd week. Upon necropsy, organs were harvested for histopathological examination. Cells from the primary tumors were recultured and tested in proliferation and invasion assays. A PCR array was used to investigate the differences in expression of 84 genes related to tumor metastasis. in the treated group, 4 rabbits developed intraocular tumors, with an average largest tumor dimension (LTD) of 2.5 mm and 5 animals reported metastatic disease. Whereas 6 rabbits in the control group developed intraocular tumors, with an average LTD of 5.8 mm and 6 animals reported metastatic disease. the recultured cells from the treated group demonstrated lower proliferation rates and were less invasive (p < 0.001). the PCR array showed differences in expression of genes related to metastasis. Notably, there was 290-fold increase in SERPINB5, a tumor suppressor gene, and a 10-fold higher expression of KISS I, a metastasis suppressor gene, in the treated group. Proangiogenic genes such as VEGFA, PDGFA and PDGFB were downregulated in the treated group. To the best of our knowledge, this is the first report detailing the altered expression of specific genes in UM cells after treatment with IM.McGill Univ, Ctr Hlth, Dept Ophthalmol & Pathol, Montreal, PQ, CanadaHenry C Witelson Ocular Pathol Lab, Montreal, PQ, CanadaUniversidade Federal de São Paulo UNIFESP EPM, Dept Ophthalmol, São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP EPM, Dept Ophthalmol, São Paulo, BrazilWeb of Scienc

    Investigating the molecular underpinnings underlying morphology and changes in carbon partitioning during tension wood formation in Eucalyptus

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    Tension wood has distinct physical and chemical properties, including altered fibre properties, cell wall composition and ultrastructure. It serves as a good system for investigating the genetic regulation of secondary cell wall biosynthesis and wood formation. The reference genome sequence for Eucalyptus grandis allows investigation of the global transcriptional reprogramming that accompanies tension wood formation in this global wood fibre crop. We report the first comprehensive analysis of physicochemical wood property changes in tension wood of Eucalyptus measured in a hybrid (E. grandis 9 Eucalyptus urophylla) clone, as well as genome-wide gene expression changes in xylem tissues 3wk post-induction using RNA sequencing. We found that Eucalyptus tension wood in field-grown trees is characterized by an increase in cellulose, a reduction in lignin, xylose and mannose, and a marked increase in galactose. Gene expression profiling in tension wood-forming tissue showed corresponding down-regulation of monolignol biosynthetic genes, and differential expression of several carbohydrate active enzymes. We conclude that alterations of cell wall traits induced by tension wood formation in Eucalyptus are a consequence of a combination of down-regulation of lignin biosynthesis and hemicellulose remodelling, rather than the often proposed up-regulation of the cellulose biosynthetic pathway.South African Department of Science and Technology (DST), Sappi and Mondi, through the Forest Molecular Genetics Programme, the Technology and Human Resources for Industry Programme (THRIP, UID 80118) and the Bioinformatics and Functional Genomics Programme of the National Research Foundation (NRF, UID 18312) of South Africa.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1469-81372016-06-30hb201

    A Spitzer-MIPS search for dust in compact high-velocity HI clouds

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    We employ three-band Spitzer-MIPS observations to search for cold dust emission in three neutral hydrogen compact high-velocity clouds (CHVCs) in the vicinity of the Milky Way. Far-infrared emission correlated with HI column density was previously reported in HVC Complex C, indicating that this object contains dust heated by the Galactic radiation field at its distance of ~10kpc. Assuming published Spitzer, IRAS, and Planck IR-HI correlations for Complex C, our Spitzer observations are of sufficient depth to directly detect 160um dust emission in the CHVCs if it is present at the same level as in Complex C, but no emission is detected in any of the targets. For one of the targets (CHVC289) which has well-localized HI clumps, we therefore conclude that it is fundamentally different from Complex C, with either a lower dust-to-gas ratio or a greater distance from the Galactic disk (and consequently cooler dust temperature). Firm conclusions cannot be drawn for the other two Spitzer-observed CHVCs since their small-scale HI structures are not sufficiently well known; nonetheless, no extended dust emission is apparent despite their relatively high HI column densities. The lack of dust emission in CHVC289 suggests that at least some compact high-velocity clouds objects may exhibit very low dust-to-gas ratios and/or greater Galactocentric distances than large HVC complexes.Comment: 8 pages, 4 figures, text and Figure 4 substantially revised to include Planck results after referee repor

    The effect of blue light exposure in an ocular melanoma animal model

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    <p>Abstract</p> <p>Background</p> <p>Uveal melanoma (UM) cell lines, when exposed to blue light in vitro, show a significant increase in proliferation. In order to determine if similar effects could be seen in vivo, we investigated the effect of blue light exposure in a xenograft animal model of UM.</p> <p>Methods</p> <p>Twenty New Zealand albino rabbits were injected with 1.0 × 10<sup>6 </sup>human UM cells (92.1) in the suprachoroidal space of the right eye. Animals were equally divided into two groups; the experimental group was exposed to blue light, while the control group was protected from blue light exposure. The eyes were enucleated after sacrifice and the proliferation rates of the re-cultured tumor cells were assessed using a Sulforhodamine-B assay. Cells were re-cultured for 1 passage only in order to maintain any in vivo cellular changes. Furthermore, Proliferating Cell Nuclear Antigen (PCNA) protein expression was used to ascertain differences in cellular proliferation between both groups in formalin-fixed, paraffin-embedded eyes (FFPE).</p> <p>Results</p> <p>Blue light exposure led to a statistically significant increase in proliferation for cell lines derived from intraocular tumors (p < 0.01). PCNA expression was significantly higher in the FFPE blue light treated group when compared to controls (p = 0.0096).</p> <p>Conclusion</p> <p>There is an increasing amount of data suggesting that blue light exposure may influence the progression of UM. Our results support this notion and warrant further studies to evaluate the ability of blue light filtering lenses to slow disease progression in UM patients.</p

    The First Post-Kepler Brightness Dips of KIC 8462852

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    We present a photometric detection of the first brightness dips of the unique variable star KIC 8462852 since the end of the Kepler space mission in 2013 May. Our regular photometric surveillance started in October 2015, and a sequence of dipping began in 2017 May continuing on through the end of 2017, when the star was no longer visible from Earth. We distinguish four main 1-2.5% dips, named "Elsie," "Celeste," "Skara Brae," and "Angkor", which persist on timescales from several days to weeks. Our main results so far are: (i) there are no apparent changes of the stellar spectrum or polarization during the dips; (ii) the multiband photometry of the dips shows differential reddening favoring non-grey extinction. Therefore, our data are inconsistent with dip models that invoke optically thick material, but rather they are in-line with predictions for an occulter consisting primarily of ordinary dust, where much of the material must be optically thin with a size scale <<1um, and may also be consistent with models invoking variations intrinsic to the stellar photosphere. Notably, our data do not place constraints on the color of the longer-term "secular" dimming, which may be caused by independent processes, or probe different regimes of a single process
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