141 research outputs found

    The land and fresh-water mollusks of Puerto Rico.

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    http://deepblue.lib.umich.edu/bitstream/2027.42/56315/1/MP070.pd

    Notes on Mollusca from Alta Vera Paz, Guatemala

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    http://deepblue.lib.umich.edu/bitstream/2027.42/56852/1/OP413.pd

    The Naiad fauna of the Huron River, in southeastern Michigan.

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    http://deepblue.lib.umich.edu/bitstream/2027.42/56285/1/MP040.pd

    Mollusca of Petn and north Alta Vera Paz, Guatemala

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    http://deepblue.lib.umich.edu/bitstream/2027.42/56279/1/MP034.pd

    Aquatic mollusks of the Upper Peninsula of Michigan

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    http://deepblue.lib.umich.edu/bitstream/2027.42/56288/1/MP043.pd

    Long-term storage and impedance-based water toxicity testing capabilities of fluidic biochips seeded with RTgill-W1 cells

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    Rainbow trout gill epithelial cells (RTgill-W1) are used in a cell-based biosensor that can respond within one hour to toxic chemicals that have the potential to contaminate drinking water supplies. RTgill-W1 cells seeded on enclosed fluidic biochips and monitored using electric cell-substrate impedance sensing (ECIS) technology responded to 18 out of the 18 toxic chemicals tested within one hour of exposure. Nine of these chemical responses were within established concentration ranges specified by the U.S. Army for comparison of toxicity sensors for field application. The RTgill-W1 cells remain viable on the biochips at ambient carbon dioxide levels at 6°C for 78 weeks without media changes. RTgill-W1 biochips stored in this manner were challenged with 9.4 μM sodium pentachlorophenate (PCP), a benchmark toxicant, and impedance responses were significant (p \u3c 0.001) for all storage times tested. This poikilothermic cell line has toxicant sensitivity comparable to a mammalian cell line (bovine lung microvessel endothelial cells (BLMVECs)) that was tested on fluidic biochips with the same chemicals. In order to remain viable, the BLMVEC biochips required media replenishments 3 times per week while being maintained at 37°C. The ability of RTgill-W1 biochips to maintain monolayer integrity without media replenishments for 78 weeks, combined with their chemical sensitivity and rapid response time, make them excellent candidates for use in low cost, maintenance-free field-portable biosensors

    The NIH-NIAID Schistosomiasis Resource Center

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    A bench scientist studying schistosomiasis must make a large commitment to maintain the parasite's life cycle, which necessarily involves a mammalian (definitive) host and the appropriate species of snail (intermediate host). This is often a difficult and expensive commitment to make, especially in the face of ever-tightening funds for tropical disease research. In addition to funding concerns, investigators usually face additional problems in the allocation of sufficient lab space to this effort (especially for snail rearing) and the limited availability of personnel experienced with life cycle upkeep. These problems can be especially daunting for the new investigator entering the field. Over 40 years ago, the National Institutes of Health–National Institute of Allergy and Infectious Diseases (NIH-NIAID) had the foresight to establish a resource from which investigators could obtain various schistosome life stages without having to expend the effort and funds necessary to maintain the entire life cycle on their own. This centralized resource translated into cost savings to both NIH-NIAID and to principal investigators by freeing up personnel costs on grants and allowing investigators to divert more funds to targeted research goals. Many investigators, especially those new to the field of tropical medicine, are only vaguely, if at all, aware of the scope of materials and support provided by this resource. This review is intended to help remedy that situation. Following a short history of the contract, we will give a brief description of the schistosome species provided, provide an estimate of the impact the resource has had on the research community, and describe some new additions and potential benefits the resource center might have for the ever-changing research interests of investigators

    The Potorous CPD Photolyase Rescues a Cryptochrome-Deficient Mammalian Circadian Clock

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    Despite the sequence and structural conservation between cryptochromes and photolyases, members of the cryptochrome/photolyase (flavo)protein family, their functions are divergent. Whereas photolyases are DNA repair enzymes that use visible light to lesion-specifically remove UV-induced DNA damage, cryptochromes act as photoreceptors and circadian clock proteins. To address the functional diversity of cryptochromes and photolyases, we investigated the effect of ectopically expressed Arabidopsis thaliana (6-4)PP photolyase and Potorous tridactylus CPD-photolyase (close and distant relatives of mammalian cryptochromes, respectively), on the performance of the mammalian cryptochromes in the mammalian circadian clock. Using photolyase transgenic mice, we show that Potorous CPD-photolyase affects the clock by shortening the period of behavioral rhythms. Furthermore, constitutively expressed CPD-photolyase is shown to reduce the amplitude of circadian oscillations in cultured cells and to inhibit CLOCK/BMAL1 driven transcription by interacting with CLOCK. Importantly, we show that Potorous CPD-photolyase can restore the molecular oscillator in the liver of (clock-deficient) Cry1/Cry2 double knockout mice. These data demonstrate that a photolyase can act as a true cryptochrome. These findings shed new light on the importance of the core structure of mammalian cryptochromes in relation to its function in the circadian clock and contribute to our further understanding of the evolution of the cryptochrome/photolyase protein family

    The state of the Martian climate

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    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes
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