320 research outputs found

    Estimation of Diversity and Community Structure Through Restriction-Fragment-Length-Polymorphism Distribution Analysis of Bacterial 16s Ribosomal-RNA Genes from a Microbial Mat at an Active, Hydrothermal Vent System, Loihi Seamount, Hawaii

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    PCR was used to amplify (eu)bacterial small-subunit (16S) rRNA genes from total-community genomic DNA. The source of total-community genomic DNA used for this culture-independent analysis was the microbial mats from a deep-sea, hydrothermal vent system, Pele\u27s Vents, located at Loihi Seamount, Hawaii. Oligonucleotides complementary to conserved regions in the 16S rRNA-encoding DNA (rDNA) of bacteria were used to direct the synthesis of PCR products, which were then subcloned by blunt-end ligation into phagemid vector pBluescript II. Restriction fragment length polymorphism patterns, created by using tandem tetrameric restriction endonucleases, revealed the presence of 12 groups of 16S rRNA genes representing discrete operational taxonomic units (OTUs). The rank order abundance of these putative OTUs was measured, and the two most abundant OTUs accounted for 72.9% of all of the 16S rDNA clones. Among the remaining 27.1% of the 16S rDNA clones, none of the 10 OTUs was represented by more than three individual clones. The cumulative OTU distribution for 48 bacterial 16S rDNA clones demonstrated that the majority of taxa represented in the clone library were detected, a result which we assume to be an estimate of the diversity of bacteria in the native hydrothermal vent habitat. 16S rDNA fingerprinting of individual clones belonging to particular OTUs by using an oligonucleotide probe that binds to a universally conserved region of the 16S rDNA fragments was conducted to confirm OTU specificity and 16S rDNA identity

    Notes on distribution and behaviour of the Rufous-winged Sunbird Cinnyris rufipennis

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    Rufous-winged Sunbird Cinnyris rufipennis is known only from Udzungwa Mountains in central Tanzania where it occurs in nine montane forests. Based on field surveys between 2011 and 2014, supplemented by observations made by all authors since the early 1990s, we provide a map showing its distribution and relative abundance. We estimate the size of the core areas where Rufous-winged Sunbird is common to c. 120 km2 and the total range to about 200 km2. We also provide data that suggests that breeding takes place during the rainy season from November to February with the breeding area usually centred on a forest glade or tree-fall gap. Finally, we describe observations of presumed lekking courtship display with up to three males assembling in a clearing and excitedly hopping from branch to branch, singing aggressively at each other with a single female observing

    Bird species richness in the montane evergreen forests of the Udzungwa Mountains, Tanzania

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    Species richness and relative abundance of montane forest birds in the Udzungwa Mountains are presented for the 11 forests larger than 1 km2. A high positive correlation between the number of montane bird species and the size of the forest is found with the highest species richness recorded in the largest forest. A few small (< 5 km2) forest fragments also support a high richness of forest birds. Their isolation from larger forest tracts is probably relatively recent (within the last 100–200 years) and their high bird species numbers may be partly due to delayed extirpations. Twenty-three restricted range montane forest species were recorded, and many of these were widespread in the Udzungwas. The largest populations of White-winged Apalis Apalis chariessa, Dapple-throat Arcanator orostruthus, Iringa Akalat Sheppardia lowei and Usambara Weaver Ploceus nicolli are most likely in Udzungwa forests. Keywords:  Tanzania, Udzungwa Mountains, montane forest birds, distribution, abundance, extinction deb

    Cultivating Agricultural Literacy: Challenge for the Liberal Arts

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    A review and analysis of 11 pacesetting experiments funded by the W. K. Kellogg Foundation to generate greater awareness among liberal arts students and faculty about the role and importance ofthe agriculture enterprise to the nation

    De novo design of immunoglobulin-like domains

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    Antibodies, and antibody derivatives such as nanobodies, contain immunoglobulin-like (Ig) β-sandwich scaffolds which anchor the hypervariable antigen-binding loops and constitute the largest growing class of drugs. Current engineering strategies for this class of compounds rely on naturally existing Ig frameworks, which can be hard to modify and have limitations in manufacturability, designability and range of action. Here, we develop design rules for the central feature of the Ig fold architecture—the non-local cross-β structure connecting the two β-sheets—and use these to design highly stable Ig domains de novo, confirm their structures through X-ray crystallography, and show they can correctly scaffold functional loops. Our approach opens the door to the design of antibody-like scaffolds with tailored structures and superior biophysical properties.This research was supported by grants from the Spanish Ministry of Science and Innovation (RYC2018-025295-I, EUR2020-112164, and PID2020-120098GA-I00). This study was also supported in part by grants from Spanish and Catalan public and private bodies (grant/fellowship references MCIN/AEI/10.13039/501100011033/PID2019-107725RG-I00, 2017SGR3 and Fundació “La Marató de TV3” 201815). S.R.M. acknowledges grant BES2016-076877 from the Spanish State Agency for Research (MCIN/AEI/10.13039/501100011033) and the European Social Fund “ESF invests in your future”. U.E. was funded by a Beatriu de Pinós post-doctoral fellowship (AGAUR-MSCA COFUND 2018BP00163. J.R.T. was supported by an EMBO postdoctoral fellowship (under grant agreement ALTF 145-2021). J.C.K. was supported by a National Science Foundation Graduate Research Fellowship (grant DGE-1256082). D.B. and T.M.C. acknowledge the Howard Hughes Medical Institute. We thank the Princess Margaret Cancer Centre for funding of the NMR facility. The Structural Genomics Consortium is a registered charity (no: 1097737) that receives funds from Bayer AG, Boehringer Ingelheim, Bristol Myers Squibb, Genentech, Genome Canada through Ontario Genomics Institute [OGI-196], EU/EFPIA/OICR/McGill/KTH/Diamond Innovative Medicines Initiative 2 Joint Undertaking [EUbOPEN grant 875510], Janssen, Merck KGaA (aka EMD in Canada and US), Pfizer and Takeda

    The Lantern Vol. 27, No. 2, Spring 1959

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    • The Case for a Stratified Society • Education Courses • Some Thoughts for God\u27s Thinking Creatures • Sawdust to the Oats? • To Change the Things I Can... • Vignette • I Meet Goliath • Reverie and Reminiscence • On Flight • In Defense of Jazz • A Description • Line of Retreat • Alan Lomax and the American Folk Song • Dawn Stillness • Seasons • Two Poems • Despair • Too Late • Education • For All Practical Purposes He Was Bald • Contrast • I Belong to the Sea • Waves • Love • The Glory and the Dreamhttps://digitalcommons.ursinus.edu/lantern/1077/thumbnail.jp
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