10 research outputs found

    A global database of lake surface temperatures collected by in situ and satellite methods from 1985–2009

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    Global environmental change has influenced lake surface temperatures, a key driver of ecosystem structure and function. Recent studies have suggested significant warming of water temperatures in individual lakes across many different regions around the world. However, the spatial and temporal coherence associated with the magnitude of these trends remains unclear. Thus, a global data set of water temperature is required to understand and synthesize global, long-term trends in surface water temperatures of inland bodies of water. We assembled a database of summer lake surface temperatures for 291 lakes collected in situ and/or by satellites for the period 1985–2009. In addition, corresponding climatic drivers (air temperatures, solar radiation, and cloud cover) and geomorphometric characteristics (latitude, longitude, elevation, lake surface area, maximum depth, mean depth, and volume) that influence lake surface temperatures were compiled for each lake. This unique dataset offers an invaluable baseline perspective on global-scale lake thermal conditions as environmental change continues

    A global database of lake surface temperatures collected by in situ and satellite methods from 1985–2009

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    Global environmental change has influenced lake surface temperatures, a key driver of ecosystem structure and function. Recent studies have suggested significant warming of water temperatures in individual lakes across many different regions around the world. However, the spatial and temporal coherence associated with the magnitude of these trends remains unclear. Thus, a global data set of water temperature is required to understand and synthesize global, long-term trends in surface water temperatures of inland bodies of water. We assembled a database of summer lake surface temperatures for 291 lakes collected in situ and/or by satellites for the period 1985–2009. In addition, corresponding climatic drivers (air temperatures, solar radiation, and cloud cover) and geomorphometric characteristics (latitude, longitude, elevation, lake surface area, maximum depth, mean depth, and volume) that influence lake surface temperatures were compiled for each lake. This unique dataset offers an invaluable baseline perspective on global-scale lake thermal conditions as environmental change continues

    Directed Migration Achieved in Mammalian Cells via Ca2+ Signal Rewiring in Synthetic Protein Chimeras

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    Synthetic biology achieves control over cellular behavior by endogenous re-wiring. Ca2+ signals allow cells to regulate diverse processes such as migration, apoptosis, motility and exocytosis. In some receptors (e.g. VEGFR2), Ca2+ signals are generated upon ligand binding (e.g. VEGF-A). Here, firstly we engineered fusion proteins that generate a Ca2+ signal upon ligand binding by creating fusions of domains that oligomerize to the transmembrane domain and the cytoplasmic tail of the VEGFR2. By coupling these chimeric proteins that generate Ca2+ signals with proteins that respond to Ca2+ signals, we re-wired, for example, dynamic cellular blebbing to increases in extracellular free Ca2+. Next, we validated this design strategy in two systems, i.e., inflammatory cytokines such as TNFα and antibodies. A system of proteins was used: an engineered TNFα chimeric receptor (named TNFR1chi), a previously engineered Ca2+-activated RhoA (named CaRQ), VSVG and thymidine kinase. Upon binding TNFα, TNFR1chi generates a Ca2+ signal that in turn activates CaRQ-mediated non-apoptotic blebs allowing migration towards the TNFα source. Next, the addition of VSVG, upon low pH induction, causes membrane fusion of the engineered and TNFα source cells. Finally, post-ganciclovir treatment, cells undergo death via the thymidine kinase suicide mechanism. Hence, this forms the basis of engineering a cell to target inflammatory disease sites characterized by TNFα secretion and a low pH microenvironment. Lastly, we exploited antibodies to bind their antigens exclusively in combination with the ability of the cytoplasmic domain of VEGFR2 to generate a Ca2+ signal upon oligomerization. Using protein fusions between antibody variants (i.e. nanobody, single-chain antibody and the monoclonal antibody) and the VEGFR2 cytoplasmic domain, Ca2+ signals were generated in response to extracellular stimulation with green fluorescent protein, mCherry, tumour necrosis factor alpha and soluble CD14. The Ca2+ signal generation by the stimulus did not require a stringent transition from monomer to oligomer state but instead, only required an increase in the oligomeric state. The Ca2+ signal generated by these classes of antibody-based fusion proteins can be rewired with a Ca2+ indicator or with an engineered Ca2+ activated RhoA to allow for antigen screening or migration to most extracellular ligands, respectively.Ph.D

    Modular assembly of synthetic proteins that span the plasma membrane in mammalian cells

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    Abstract Background To achieve synthetic control over how a cell responds to other cells or the extracellular environment, it is important to reliably engineer proteins that can traffic and span the plasma membrane. Using a modular approach to assemble proteins, we identified the minimum necessary components required to engineer such membrane-spanning proteins with predictable orientation in mammalian cells. Results While a transmembrane domain (TM) fused to the N-terminus of a protein is sufficient to traffic it to the endoplasmic reticulum (ER), an additional signal peptidase cleavage site downstream of this TM enhanced sorting out of the ER. Next, a second TM in the synthetic protein helped anchor and accumulate the membrane-spanning protein on the plasma membrane. The orientation of the components of the synthetic protein were determined through measuring intracellular Ca2+ signaling using the R-GECO biosensor and through measuring extracellular quenching of yellow fluorescent protein variants by saturating acidic and salt conditions. Conclusions This work forms the basis of engineering novel proteins that span the plasma membrane to potentially control intracellular responses to extracellular conditions

    Additional file 1: Figure S1. of Modular assembly of synthetic proteins that span the plasma membrane in mammalian cells

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    Fluorescence images of CHO cells transfected with the plasma membrane labelled Lyn-Ceru and ER labelled STIM1-mRFP markers. CHO cells transfected with the plasma membrane labelled Lyn-Ceru showed a matte-like appearance (a, f and k) while those transfected with the ER labelled STIM1-mRFP showed a web-like fluorescence distribution (d, i and n). TM-Venus (b), TLP-Venus (g) or TLP-V-TM (l) peptides show a shift in fluorescence distribution from a wholly ER (b) to a slight (g) and then an entirely membrane appearance (l). Merged images illustrate resultant co-localization (c, e, h, j, m and o). TM: transmembrane domain TLR4, TLP: fusion of TM with signal peptidase cleavage site from human immunoglobulin K, V: Venus fluorescent protein, LC: Lyn-Ceru, STIM1: stromal interaction molecule 1. Scale bars are 10 Οm. Images are false colored: CFP, cyan; YFP, green; mRFP, red. All insets show zoomed regions (4x) of structures in dotted rectangles. All experiments were repeated at least 3 times. (PDF 9198 kb

    Frequency of Infection in Cervical Lymph Node Biopsy Site using Chlorhexidine and Povidine Iodine

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    Abstract: Background: Lymph node are located throughout the lymphatic system, they are concentrated in certain areas of the body including head and neck. Cervical lymph nodes are lymph nodes found in the neck. Of the 800 lymph nodes in the human body, 300 are in the neck. Cervical lymph nodes are subject to several different pathological conditions including tumours, infection and inflammation. Methodology: The Povidine-iodine and chlorhexidine for preoperative skin preparation in cervical lymph node biopsy procedure were used in this study and patients were asked for follow up after a week. On follow up day their wounds were checked, assessed and withdraw all stiches and complications were recorded accordingly and analysed them. It was discussed and showed that which one of Povidine-iodine and chlorhexidine is best to use for preoperative skin preparation in cervical lymph node biopsy procedures to reduce surgical site infection and economical one. Results: Out of 150 patients, 46% (69) were males and 54% (81) were females that had cervical lymphadenopathy after skin preparation by chlorhexidine antiseptic solution showed frequency of infection in total of 150 patients 16.67% (25) were infected while the other 83.33%(125) were not infected. Out of 150 patients who were underwent cervical lymphadenopathy after using povidine iodine skin preparatory antiseptic solution, 42% (63) were males and 58% (87) were females and among those frequency of infection showed 44.67% (67) were infected while the others 55.33% (83) were not. Conclusion: Preoperative scrubbing of the patient’s skin with chlorhexidine–alcohol is better than scrubbing with povidone–iodine for preventing surgical-site infection after cervical lymph node biopsy

    A global database of lake surface temperatures collected by in situ and satellite methods from 1985-2009

    No full text
    Global environmental change has influenced lake surface temperatures, a key driver of ecosystem structure and function. Recent studies have suggested significant warming of water temperatures in individual lakes across many different regions around the world. However, the spatial and temporal coherence associated with the magnitude of these trends remains unclear. Thus, a global data set of water temperature is required to understand and synthesize global, long-term trends in surface water temperatures of inland bodies of water. We assembled a database of summer lake surface temperatures for 291 lakes collected in situ and/or by satellites for the period 1985–2009. In addition, corresponding climatic drivers (air temperatures, solar radiation, and cloud cover) and geomorphometric characteristics (latitude, longitude, elevation, lake surface area, maximum depth, mean depth, and volume) that influence lake surface temperatures were compiled for each lake. This unique dataset offers an invaluable baseline perspective on global-scale lake thermal conditions as environmental change continues

    A global database of lake surface temperatures collected by in situ and satellite methods from 1985–2009

    Get PDF
    Global environmental change has influenced lake surface temperatures, a key driver of ecosystem structure and function. Recent studies have suggested significant warming of water temperatures in individual lakes across many different regions around the world. However, the spatial and temporal coherence associated with the magnitude of these trends remains unclear. Thus, a global data set of water temperature is required to understand and synthesize global, long-term trends in surface water temperatures of inland bodies of water. We assembled a database of summer lake surface temperatures for 291 lakes collected in situ and/or by satellites for the period 1985–2009. In addition, corresponding climatic drivers (air temperatures, solar radiation, and cloud cover) and geomorphometric characteristics (latitude, longitude, elevation, lake surface area, maximum depth, mean depth, and volume) that influence lake surface temperatures were compiled for each lake. This unique dataset offers an invaluable baseline perspective on global-scale lake thermal conditions as environmental change continues
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