47 research outputs found
Data from: Plants and mycorrhizal symbionts acquire substantial soil nitrogen from gaseous ammonia transport
No full textPlease cite as: Hestrin, Rachel, Weber, Peter K., Pett-Ridge, Jennifer, and Lehmann, Johannes. (2021) Plants and mycorrhizal symbionts acquire substantial soil nitrogen from gaseous ammonia transport. New Phytologist. [Dataset] Cornell University Library eCommons Repository. https://doi.org/10.7298/q898-5m03data in support of research on
1) Nitrogen (N) is an essential nutrient that limits plant growth in many ecosystems. Here we investigate an overlooked component of the terrestrial N cycle—subsurface ammonia (NH3) gas transport and its contribution to plant and mycorrhizal N acquisition.
2) We used controlled mesocosms, soil incubations, stable isotopes, and imaging to investigate edaphic drivers of NH3 gas efflux, track lateral subsurface N transport originating from 15NH3 gas or 15N-enriched organic matter, and assess plant and mycorrhizal N assimilation from this gaseous transport pathway.
3) NH3 is released from soil organic matter, travels below ground, and contributes to root and fungal N content. Abiotic soil properties (pH and texture) influence the quantity of NH3 available for subsurface transport. Mutualisms with arbuscular mycorrhizal (AM) fungi can substantially increase plant NH3-N uptake. The grass Brachypodium distachyon acquired 6-9% of total plant N from organic matter-N that traveled as a gas below ground. Colonization by the AM fungus Rhizophagus irregularis was associated with a twofold increase in total plant N acquisition from subsurface NH3 gas.
4) NH3 gas transport and uptake pathways may be fundamentally different from those of more commonly studied soil N species and warrant further research.This work was supported in part by the Cornell Atkinson Center for Sustainability. RH acknowledges support from the NSF IGERT Program (DGE-0903371 and DGE-1069193), NSF-BREAD (grant number IOS-0965336), and the NSF GRFP (DGE-1144153). This research was also supported in part by the U.S. Department of Energy Office of Biological and Environmental Research, Genomic Science Program LLNL Bioenergy Scientific Focus Area SCW1039. Work at LLNL was conducted under the auspices of DOE Contract DE-AC52-07NA27344. Special thanks to Akio Enders for help with experimental design, Kelly Hanley for help with sample collection, Kim Sparks and Cornell Stable Isotope Facility staff for help with IRMS analysis, Christina Ramon for help with NanoSIMS sample preparation, and Maria Harrison for providing the plant and fungal germplasm
Analogue to Digital and Digital to Analogue (AD/DA) Conversion Techniques: An Overview
No full text
The basic ideas behind modern Analogue to Digital and Digital to Analogue (AD/DA) conversion methods will be introduced: a general view of the importance of these devices will be given, along with the digital representation of time-varying, real-world analogue signals. Some CERN applications will be outlined.
The variety of conversion methods, their limitations, error sources and measurement methods will form the major part of this presentation. A review of the technological progress in this field over the last 30 years will be presented, concluding with the present 'state of the art' and a quick look at what is just around the corner.
This Technical Training Seminar is in the framework of the FEED-2002 Lecture Series, and it is a prerequisite to attending to any of the FEED-2002 Terms. FEED-2002 is a two-term course that will review the techniques dealing with closed loop systems, focussing on time-invariant linear systems.
(free attendance, no registration required)
More information on the FEED-2002 Web page: http://www.cern.ch/TechnicalTraining/special/FEED2002.asp
Organiser(s): Davide Vitè, Mick Storr / HR-TD</I
Evaluation of subcutaneous proleukin (Interleukin-2) in a randomized international trial (ESPRIT): Geographical and gender differences in the baseline characteristics of participants
No full textBackground: ESPRIT, is a phase III, open-label, randomized, international clinical trial evaluating the effects of subcutaneous recombinant interleukin-2 (rIL-2) plus antiretroviral therapy (ART) versus ART alone on HIV-disease progression and death in HIV-1-infected individuals with CD4+ T-cells ≥300 cells/μL. Objectives: To describe the baseline characteristics of participants randomized to ESPRIT overall and by geographic location. Method: Baseline characteristics of randomized participants were summarized by region. Results: 4,150 patients were enrolled in ESPRIT from 254 sites in 25 countries. 41%, 27%, 16%, 11%, and 5% were enrolled in Europe, North America, South America, Asia, and Australia, respectively. The median age was 40 years, 81% were men, and 76%, 11%, and 9% were Caucasian, Asian, and African American or African, respectively. 44% of women enrolled (n = 769) were enrolled in Thailand and Argentina. Overall, 55% and 38% of the cohort acquired HIV through male homosexual and heterosexual contact, respectively. 25% had a prior history of AIDS-defining illness; Pneumocystis jirovecii pneumonia, M. tuberculosis, and esophageal candida were most commonly reported. Median nadir and baseline CD4+ T-cell counts were 199 and 458 cells/μL, respectively. 6% and 13% were hepatitis B or C virus coinfected, respectively. Median duration of antiretroviral therapy (ART) was 4.2 years; the longest median duration was in Australia (5.2 years) and the shortest was in Asia (2.3 years). 17%, 13%, and 69% of participants began ART before 1995, between 1996 and 1997, and from 1998 onward, respectively. 86% used ART from two or more ART classes, with 49% using a protease inhibitor-based regimen and 46% using a nonnucleoside reverse transcriptase inhibitor-based regimen. 78% had plasma HIV RNA below detection (<500 cp/mL). Conclusion: ESPRIT has enrolled a diverse population of HIV-infected individuals including large populations of women and patients of African-American/African and Asian ethnicity often underrepresented in HIV research. As a consequence, the results of the study may have wide global applicability
I am no inconsiderable Shop-Keeper in this Town Swift and his Dublin Printers of the 1720's: Edward Waters, John Harding and Sarah Harding
No full textThis thesis represents the first-ever full-length study of Swift’s dealings and working relationships with the Dublin printers who took the risk on his seditious Irish pamphlets of the 1720’s. These printers were: Edward Waters, who endured a violent and protracted prosecution for printing Swift’s A Proposal for the Universal Use of Irish Manufacture in May 1720; John Harding, who died as a consequence of his imprisonment for printing the fourth of Swift’s Drapier’s Letters in October 1724; and Harding’s widow, Sarah, who came to print occasional works for Swift a few years after her husband’s death. Written from the perspectives of the printers, the thesis discloses a substantial amount of never-before-seen evidence pertaining to the lives and careers of the printers, the form and nature of their working relationships with Swift, the legal and moral obligations Swift owed them as a pseudonymous author, as well as the circumstances of Harding’s death. Historians have assumed that Harding died of jail fever – an assumption that wholly absolves Swift. But new evidence suggests the clear possibility that Harding, who was due to appear in the Court of King’s Bench, where he would have been examined at length on the true identity of this ‘M.B. Drapier’, met with foul play, and that the persons behind it were Swift’s friend, Lord Lieutenant Carteret, and Swift himself. Further never-before-seen evidence concerns Sarah’s Harding’s suppressed complaints and the persistent pressure that Swift’s friends brought to bear upon the author to support her in the years following Harding’s death
Integrating Bird Strike Risk Information into the Airport Management System
No full textThe calibration of Angular Accelerometers requires a controlled test with a known accel- eration pro_le. However, current turn-tables have been designed primarily for generating a constant rotational velocity. To generate a pro_le with varying angular acceleration we propose using constant rotational velocity on the two axes of a 2-axes motion simulator. The proposed sequence was developed to obtain the required rotational acceleration signal quality using only rotational velocity input. The identi_ed pattern is applied to an enve- lope of test conditions, resulting in test matrix. This method provides an alternative means to generate inputs that can be used to calibrate angular accelerometers using calibration hardware that is not primarily designed to provide accurate acceleration inputs.Control & Simulatio
Pharmacogenetics of ophthalmic topical β-blockers
No full textGlaucoma is the second leading cause of blindness worldwide. The primary glaucoma risk factor is elevated intraocular pressure. Topical β-blockers are affordable and widely used to lower intraocular pressure. Genetic variability has been postulated to contribute to interpersonal differences in efficacy and safety of topical β-blockers. This review summarizes clinically significant polymorphisms that have been identified in the β-adrenergic receptors (ADRB1, ADRB2 and ADRB3). The implications of polymorphisms in CYP2D6 are also discussed. Although the candidate-gene approach has facilitated significant progress in our understanding of the genetic basis of glaucoma treatment response, most drug responses involve a large number of genes, each containing multiple polymorphisms. Genome-wide association studies may yield a more comprehensive set of polymorphisms associated with glaucoma outcomes. An understanding of the genetic mechanisms associated with variability in individual responses to topical β-blockers may advance individualized treatment at a lower cost
Cadastral Surveying in Colonial South Carolina: a Historical Geography.
No full textColonial South Carolina\u27s cadastral pattern evolved as the product of a variety of factors. Foremost was the ability of settlers to choose the sites of their landholdings. This authority was limited, however, by official policies that prevented settlers from determining the size, shape, and quality of land in their grants. Expressed rules for surveying riparian and inland tracts in rectangular shapes resulted in a more regular pattern of landownership than is generally assumed in a metes and bounds survey. Within the guidelines of these and other policies, colonist nonetheless were permitted to occupy land in non-contiguous tracts resulting in a patchwork pattern of land tenure. The metes and bounds survey system used in South Carolina was not haphazard or random. From the earliest settlement in 1670, surveyors used a magnetic compass and chain to mark out boundaries consistent with the intended shape and amount of acreage to which a settle was entitled. Because it was logistically easier for early surveyors to lay out rectangular shapes, their methods likely reinforced the policies for such regularity promoted by colonial officials. As South Carolinians began more often to claim contiguous properties, the weaknesses of the metes and bounds survey system were revealed in increasing numbers of property disputes. Sources of survey errors included poor instruments, inexact techniques, and mistakes or miscalculations made by surveyors. Perhaps the most serious cause of dispute and the one most commonly brought to litigation was the surveyor\u27s failure to survey all boundaries of a tract of land, or to field check previous claims. Another major area of dispute among landowners involved claims on physical features such as swamp or marsh land, rivers, and riverine or coastal submerged land. Most such disputes appeared to result from changing conceptions through time regarding their use. Any cadastral pattern is determined by the settlement type and South Carolina\u27s is no exception. Colonists chose initially to occupy land in isolated non-contiguous tracts, thereby creating oddly shaped parcels in between. The resulting patchwork pattern of landownership supports this fact. It is erroneous to assume, however, that this nonsystematic appearance reflects completely haphazard or helter skelter land apportionment. (Abstract shortened with permission of author.)
The interplay of strategic orientations and their influence on sme performance
No full text©Authors. Author(s) hereby grant to Publisher all right, title, and interest in and to the Work, including copyright to all means of expression by any method now known or hereafter developed, including electronic format. If Publisher does not publish the Work within two (2) years of the Effective Date, copyright shall revert back to the Author. Publisher agrees to always credit Author(s) as the author(s) of the Work.This paper examines the role that learning orientation plays with respect to entrepreneurial orientation, market orientation, and, ultimately, the performance of small and medium-sized enterprises SMEs. Previous research indicated mixed findings in regards to the relationship of these strategic orientations and firm performance. Instead of just direct influences to performance, we examine if learning orientation is an antecedent to market and entrepreneurial orientation. We suggest that in this way, their influence to SME performance would be more accurately predicted. We argue that learning orientation reflects the overall values of the organization, whereas entrepreneurial and market orientations are more action-oriented firm behaviors. Learning orientation would likely set the stage for the requisite actions implied in market and entrepreneurial orientation. Direct effect and mediated effects hypotheses between these strategic orientations are tested on a sample of SME manufacturing firms and their performance. Findings indicate that learning and entrepreneurial orientation directly influence SME performance. However, when learning orientation and its effects are mediated by market and entrepreneurial orientation, direct effects disappear when testing this model. The study offers insight into relationships between various strategic orientations, as to how and when they might influence SME performance
Reply to Halanych et al.:Ctenophore misplacement is corroborated by independent datasets
No full textIn their letter, Halanych et al. (1) criticize our recent assertion (2) that the phylogenetic placement of ctenophores as the sister group to all other animals (the Ctenophora-sister hypothesis) in three previous studies (3⇓–5) was an artifact caused by undetected systematic error.Halanych et al. (1) claim we used no “objective approaches” to identify sources of systematic error. In fact, we used an objective comparison of Bayesian cross-validation scores to select the best-fitting substitution model, because poorly fitting models are a frequent source of systematic error. Halanych et al. point out that this comparison did not include partitioned site-homogeneous models. However, they do not mention that only one of the… [see full text
Genomic data do not support comb jellies as the sister group to all other animals
No full textUnderstanding how complex traits, such as epithelia, nervous systems, muscles, or guts, originated depends on a well-supported hypothesis about the phylogenetic relationships among major animal lineages. Traditionally, sponges (Porifera) have been interpreted as the sister group to the remaining animals, a hypothesis consistent with the conventional view that the last common animal ancestor was relatively simple and more complex body plans arose later in evolution. However, this premise has recently been challenged by analyses of the genomes of comb jellies (Ctenophora), which, instead, found ctenophores as the sister group to the remaining animals (the “Ctenophora-sister” hypothesis). Because ctenophores are morphologically complex predators with true epithelia, nervous systems, muscles, and guts, this scenario implies these traits were either present in the last common ancestor of all animals and were lost secondarily in sponges and placozoans (Trichoplax) or, alternatively, evolved convergently in comb jellies. Here, we analyze representative datasets from recent studies supporting Ctenophora-sister, including genome-scale alignments of concatenated protein sequences, as well as a genomic gene content dataset. We found no support for Ctenophora-sister and conclude it is an artifact resulting from inadequate methodology, especially the use of simplistic evolutionary models and inappropriate choice of species to root the metazoan tree. Our results reinforce a traditional scenario for the evolution of complexity in animals, and indicate that inferences about the evolution of Metazoa based on the Ctenophora-sister hypothesis are not supported by the currently available data
