275 research outputs found

    Using MODIS Satellite Images to Confirm Distributed Snowmelt Model Results in a Small Arctic Watershed

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    Environmental analysts face the problem of obtaining distributed measurements to evaluate the performance of models with increasingly small spatiotemporal resolution. While U.S. government agencies readily provide both measurement products and data tools for the study of global change occurring over entire seasons and across continental areas, analysts need access to the low-level data that provides the basis for global products. Finally, analysts need to consider sensor errors inherent in low-level products that are accounted for in global, composite products. Hydrologists using tools for managing low-level snow swath measurements, in particular, must consider how measurements are affected by sensor errors like snow-cloud confusion and sensor errors due to low ground illumination at night. This thesis aims to explore the use of remotely sensed snow maps to confirm a time series of model maps. Specifically, snow covered area (SCA) measurements remotely sensed by the National Aeronautics and Space Administration (NASA) are used to confirm SCA predictions modeled by the United States Agriculture Department (USDA). The measurements come from the two Moderate Resolution Imaging Spectroradiometer (MODIS) sensors aboard near-polar, sun-synchronous satellites named Aqua and Terra. The USDA calls the model TOPMODEL-Based Land-Atmosphere Transfer Scheme (TOPLATS). The Upper Kuparuk River Watershed (UKRW) on the North Slope of Alaska acts as the case study location. To meet the map-comparison goal, the Kappa statistic, Kappa statistic variants, and probability density functions expressing measurement uncertainty in discrete scenes all evaluate the ability of MODIS measurements to confirm the accuracy of TOPLATS model maps. Data management objectives to make measured data accessible and comparable to the model output comprise a supporting goal. Results show that individual composite statistics, like the proportion of agreement between two maps, can easily obscure spatiotemporally distributed confirmation information without additional statistics and side-by-side images of measurement maps and model maps. These tools show some promise for using MODIS to confirm model predictions of snowmelt that occur across less than 150 km2 and less than a few days, however, clouds and malfunctioning sensors limit such use

    Environmental Advocacy Messages: Relationships Between the Messages that Constituents Send to Decision Makers and Organizational Engagement

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    Environmental advocacy organizations aim to help citizens contact their policymakers, to recruit new members, and to increase their contacts’ level of engagement with organization issues. They use online petitions and form-letter services for these purposes. These services put citizens in contact with policymakers and encourage citizens to take follow-up actions, such as sending another message, referring a friend, or making a donation. While these services effectively recruit members, they marginally influence policymakers. To increase influence, organizations now ask petitioners to include personal messages in their communications. This dissertation asks if text analysis of these personal messages can help advocacy organizations further fulfill their recruitment and engagement goals. It investigates text-metrics both for predicting engagement from existing contacts and for services, such as chatbots, to suggest follow-up actions to new contacts. Methods employ rule-based text analysis tools (LIWC, VADER, Flesch Reading Ease, and Regular Expressions) to pilot the use of pronouns, sentiment, writing complexity, and the identification of personal stories as predictors of engagement. Data include over two million messages and nearly 500,000 personal messages from over 150,000 individuals supporting sustainable policies and projects. Results reveal relationships between messages and two engagement factors: (1) the number of messages that groups of contacts send and (2) payment of membership dues. Results also bolster research that highlights the importance of identifying contacts who can share stories about how environmental issues have affected them. Conclusions encourage advocacy organizations and policymakers to analyze messages to increase engagement and understand constituency support of policies and projects. Future work may integrate text analysis into membership models and advocacy services. Future work may also improve personal story classification and investigate machine-learning for identifying potential members

    Robo2 determines subtype-specific axonal projections of trigeminal sensory neurons

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    How neurons connect to form functional circuits is central to the understanding of the development and function of the nervous system. In the somatosensory system, perception of sensory stimuli to the head requires specific connections between trigeminal sensory neurons and their many target areas in the central nervous system. Different trigeminal subtypes have specialized functions and downstream circuits, but it has remained unclear how subtype-specific axonal projection patterns are formed. Using zebrafish as a model system, we followed the development of two trigeminal sensory neuron subtypes: one that expresses trpa1b, a nociceptive channel important for sensing environmental chemicals; and a distinct subtype labeled by an islet1 reporter (Isl1SS). We found that Trpa1b and Isl1SS neurons have overall similar axon trajectories but different branching morphologies and distributions of presynaptic sites. Compared with Trpa1b neurons, Isl1SS neurons display reduced branch growth and synaptogenesis at the hindbrain-spinal cord junction. The subtype-specific morphogenesis of Isl1SS neurons depends on the guidance receptor Robo2. robo2 is preferentially expressed in the Isl1SS subset and inhibits branch growth and synaptogenesis. In the absence of Robo2, Isl1SS afferents acquire many of the characteristics of Trpa1b afferents. These results reveal that subtype-specific activity of Robo2 regulates subcircuit morphogenesis in the trigeminal sensory system

    Robo2 determines subtype-specific axonal projections of trigeminal sensory neurons

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    How neurons connect to form functional circuits is central to the understanding of the development and function of the nervous system. In the somatosensory system, perception of sensory stimuli to the head requires specific connections between trigeminal sensory neurons and their many target areas in the central nervous system. Different trigeminal subtypes have specialized functions and downstream circuits, but it has remained unclear how subtype-specific axonal projection patterns are formed. Using zebrafish as a model system, we followed the development of two trigeminal sensory neuron subtypes: one that expresses trpa1b, a nociceptive channel important for sensing environmental chemicals; and a distinct subtype labeled by an islet1 reporter (Isl1SS). We found that Trpa1b and Isl1SS neurons have overall similar axon trajectories but different branching morphologies and distributions of presynaptic sites. Compared with Trpa1b neurons, Isl1SS neurons display reduced branch growth and synaptogenesis at the hindbrain-spinal cord junction. The subtype-specific morphogenesis of Isl1SS neurons depends on the guidance receptor Robo2. robo2 is preferentially expressed in the Isl1SS subset and inhibits branch growth and synaptogenesis. In the absence of Robo2, Isl1SS afferents acquire many of the characteristics of Trpa1b afferents. These results reveal that subtype-specific activity of Robo2 regulates subcircuit morphogenesis in the trigeminal sensory system

    Long-term maintenance of certolizumab pegol safety and efficacy, in combination with methotrexate and as monotherapy, in rheumatoid arthritis patients

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    Introduction The safety and efficacy of certolizumab pegol (CZP) 400 mg every 4 weeks (Q4W) monotherapy (FAST4WARD/NCT00548834) and in combination with methotrexate (MTX) (014/NCT00544154) in active rheumatoid arthritis (RA) has been published previously. This report outlines final long-term outcomes from the open-label extension (OLE) study (015/NCT00160693), which enrolled patients from these randomized controlled trials (RCTs). Methods Patients who withdrew from or completed the 24-week 014/FAST4WARD RCTs were enrolled and received CZP 400 mg Q4W with/without MTX. Exposure-adjusted event rates (ER) per 100 patient-years (PYs) of adverse events (AEs) and serious AEs (SAEs) were reported for all patients receiving ≥1 dose of CZP in RCTs or OLE (N = 427) between first CZP dose and up to 24 weeks after last CZP dose or study withdrawal. Efficacy assessments included clinical (ACR20/50/70 response rates, TJC, SJC) and patient-reported outcomes (HAQ-DI, PtGADA, pain, fatigue) to week 304 (5.8 years) in the CZP intent-to-treat population. SDAI and CDAI outcomes were analyzed post hoc. Outcomes for CZP monotherapy and CZP+MTX combination-therapy were compared. Results Globally, ERs of AEs and SAEs were 408.1 and 25.2 per 100 PY, respectively. Eleven patients had AEs leading to death (ER 0.6). Improvements in clinical and patient-reported outcomes during the 24-week RCTs were maintained to week 304, and were similar between all subpopulations. Conclusions The longest exposure duration to date with CZP 400 mg Q4W treatment confirmed the safety profile observed in previous studies. Initial improvements in signs and symptoms of RA, including PROs, were maintained in both CZP monotherapy and CZP + MTX combination-therapy patients

    Reduced epithelial suppressor of cytokine signalling 1 in severe eosinophilic asthma

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    Severe asthma represents a major unmet clinical need. Eosinophilic inflammation persists in the airways of many patients with uncontrolled asthma, despite high-dose inhaled corticosteroid therapy. Suppressors of cytokine signalling (SOCS) are a family of molecules involved in the regulation of cytokine signalling via inhibition of the Janus kinase–signal transducers and activators of transcription pathway. We examined SOCS expression in the airways of asthma patients and investigated whether this is associated with persistent eosinophilia.Healthy controls, mild/moderate asthmatics and severe asthmatics were studied. Whole genome expression profiling, quantitative PCR and immunohistochemical analysis were used to examine expression of SOCS1, SOCS2 and SOCS3 in bronchial biopsies. Bronchial epithelial cells were utilised to examine the role of SOCS1 in regulating interleukin (IL)-13 signalling in vitro.SOCS1 gene expression was significantly lower in the airways of severe asthmatics compared with mild/moderate asthmatics, and was inversely associated with airway eosinophilia and other measures of T-helper type 2 (Th2) inflammation. Immunohistochemistry demonstrated SOCS1 was predominantly localised to the bronchial epithelium. SOCS1 overexpression inhibited IL-13-mediated chemokine ligand (CCL) 26 (eotaxin-3) mRNA expression in bronchial epithelial cells.Severe asthma patients with persistent airway eosinophilia and Th2 inflammation have reduced airway epithelial SOCS1 expression. SOCS1 inhibits epithelial IL-13 signalling, supporting its key role in regulating Th2-driven eosinophilia in severe asthma.</jats:p

    Increased autophagy-related 5 gene expression is associated with collagen expression in the airways of refractory asthmatics

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    Background: Fibrosis, particularly excessive collagen deposition, presents a challenge for treating asthmatic individuals. At present, no drugs can remove or reduce excessive collagen in asthmatic airways. Hence, the identification of pathways involved in collagen deposition would help to generate therapeutic targets to interfere with the airway remodeling process. Autophagy, a cellular degradation process, has been shown to be dysregulated in various fibrotic diseases, and genetic association studies in independent human populations have identified autophagy-related 5 (ATG5) to be associated with asthma pathogenesis. Hence, the dysregulation of autophagy may contribute to fibrosis in asthmatic airways. Objective: This study aimed to determine if (1) collagen deposition in asthmatic airways is associated with ATG5 expression and (2) ATG5 protein expression is associated with asthma per se and severity. Methods: Gene expression of transforming growth factor beta 1, various asthma-related collagen types [collagen, type I, alpha 1; collagen, type II, alpha 1; collagen, type III, alpha 1; collagen, type V, alpha 1 (COL5A1) and collagen, type V, alpha 2], and ATG5 were measured using mRNA isolated from bronchial biopsies of refractory asthmatic subjects and assessed for pairwise associations. Protein expression of ATG5 in the airways was measured and associations were assessed for asthma per se, severity, and lung function. Main results: In refractory asthmatic individuals, gene expression of ATG5 was positively associated with COL5A1 in the airways. No association was detected between ATG5 protein expression and asthma per se, severity, and lung function. Conclusion and clinical relevance: Positive correlation between the gene expression patterns of ATG5 and COL5A1 suggests that dysregulated autophagy may contribute to subepithelial fibrosis in the airways of refractory asthmatic individuals. This finding highlights the therapeutic potential of ATG5 in ameliorating airway remodeling in the difficult-to-treat refractory asthmatic individuals

    The novel, small-molecule DNA methylation inhibitor SGI-110 as an ovarian cancer chemosensitizer

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    PURPOSE: To investigate SGI-110 as a "chemosensitizer" in ovarian cancer and to assess its effects on tumor suppressor genes (TSG) and chemoresponsiveness-associated genes silenced by DNA methylation in ovarian cancer. EXPERIMENTAL DESIGN: Several ovarian cancer cell lines were used for in vitro and in vivo platinum resensitization studies. Changes in DNA methylation and expression levels of TSG and other cancer-related genes in response to SGI-110 were measured by pyrosequencing and RT-PCR. RESULTS: We demonstrate in vitro that SGI-110 resensitized a range of platinum-resistant ovarian cancer cells to cisplatin (CDDP) and induced significant demethylation and reexpression of TSG, differentiation-associated genes, and putative drivers of ovarian cancer cisplatin resistance. In vivo, SGI-110 alone or in combination with CDDP was well tolerated and induced antitumor effects in ovarian cancer xenografts. Pyrosequencing analyses confirmed that SGI-110 caused both global (LINE1) and gene-specific hypomethylation in vivo, including TSGs (RASSF1A), proposed drivers of ovarian cancer cisplatin resistance (MLH1 and ZIC1), differentiation-associated genes (HOXA10 and HOXA11), and transcription factors (STAT5B). Furthermore, DNA damage induced by CDDP in ovarian cancer cells was increased by SGI-110, as measured by inductively coupled plasma-mass spectrometry analysis of DNA adduct formation and repair of cisplatin-induced DNA damage. CONCLUSIONS: These results strongly support further investigation of hypomethylating strategies in platinum-resistant ovarian cancer. Specifically, SGI-110 in combination with conventional and/or targeted therapeutics warrants further development in this setting

    A myeloid program associated with COVID-19 severity is decreased by therapeutic blockade of IL-6 signaling

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    Altered myeloid inflammation and lymphopenia are hallmarks of severe infections. We identified the upregulated EN-RAGE gene program in airway and blood myeloid cells from patients with acute lung injury from SARS-CoV-2 or other causes across 7 cohorts. This program was associated with greater clinical severity and predicted future mechanical ventilation and death. EN-RAGE hi myeloid cells express features consistent with suppressor cell functionality, including low HLA-DR and high PD-L1. Sustained EN-RAGE program expression in airway and blood myeloid cells correlated with clinical severity and increasing expression of T cell dysfunction markers. IL-6 upregulated many EN-RAGE program genes in monocytes in vitro. IL-6 signaling blockade by tocilizumab in a placebo-controlled clinical trial led to rapid normalization of EN-RAGE and T cell gene expression. This identifies IL-6 as a key driver of myeloid dysregulation associated with worse clinical outcomes in COVID-19 patients and provides insights into shared pathophysiological mechanisms in non-COVID-19 ARDS. </p
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