210 research outputs found
Using industrial engineering techniques in the development of effective cost accounting systems for hospitals
Call number: LD2668 .R4 IE 1988 O36Master of ScienceIndustrial and Manufacturing Systems Engineerin
EMIS-2017 Ireland: findings from the European men who have sex with men Internet Survey (Ireland).
Effect of Lactobacillus salivarius Bacteriocin Abp118 on the Mouse and Pig Intestinal Microbiota
Lactobacilli are Gram-positive bacteria that are a subdominant element in the human gastrointestinal microbiota, and which are commonly used in the food industry. Some lactobacilli are considered probiotic, and have been associated with health benefits. However, there is very little culture-independent information on how consumed probiotic microorganisms might affect the entire intestinal microbiota. We therefore studied the impact of the administration of Lactobacillus salivarius UCC118, a microorganism well characterized for its probiotic properties, on the composition of the intestinal microbiota in two model animals. UCC118 has anti-infective activity due to production of the bacteriocin Abp118, a broad-spectrum class IIb bacteriocin, which we hypothesized could impact the microbiota. Mice and pigs were administered wild-type (WT) L. salivarius UCC118 cells, or a mutant lacking bacteriocin production. The microbiota composition was determined by pyrosequencing of 16S rRNA gene amplicons from faeces. The data show that L. salivarius UCC118 administration had no significant effect on proportions of major phyla comprising the mouse microbiota, whether the strain was producing bacteriocin or not. However, L. salivarius UCC118 WT administration led to a significant decrease in Spirochaetes levels, the third major phylum in the untreated pig microbiota. In both pigs and mice, L. salivarius UCC118 administration had an effect on Firmicutes genus members. This effect was not observed when the mutant strain was administered, and was thus associated with bacteriocin production. Surprisingly, in both models, L. salivarius UCC118 administration and production of Abp118 had an effect on Gram-negative microorganisms, even though Abp118 is normally not active in vitro against this group of microorganisms. Thus L. salivarius UCC118 administration has a significant but subtle impact on mouse and pig microbiota, by a mechanism that seems at least partially bacteriocin-dependent
Astro2020: Empirically Constraining Galaxy Evolution
Over the past decade, empirical constraints on the galaxy-dark matter halo
connection have significantly advanced our understanding of galaxy evolution.
Past techniques have focused on connections between halo properties and galaxy
stellar mass and/or star formation rates. Empirical techniques in the next
decade will link halo assembly histories with galaxies' circumgalactic media,
supermassive black holes, morphologies, kinematics, sizes, colors,
metallicities, and transient rates. Uncovering these links will resolve many
critical uncertainties in galaxy formation and will enable much higher-fidelity
mock catalogs essential for interpreting observations. Achieving these results
will require broader and deeper spectroscopic coverage of galaxies and their
circumgalactic media; survey teams will also need to meet several criteria
(cross-comparisons, public access, and covariance matrices) to facilitate
combining data across different surveys. Acting on these recommendations will
continue enabling dramatic progress in both empirical modeling and galaxy
evolution for the next decade.Comment: Science white paper submitted to the Astro2020 Decadal Surve
Social considerations are crucial to success in implementing the 30×30 global conservation target
Astro2020 APC White Paper: The Early Career Perspective on the Coming Decade, Astrophysics Career Paths, and the Decadal Survey Process
In response to the need for the Astro2020 Decadal Survey to explicitly engage
early career astronomers, the National Academies of Sciences, Engineering, and
Medicine hosted the Early Career Astronomer and Astrophysicist Focus Session
(ECFS) on October 8-9, 2018 under the auspices of Committee of Astronomy and
Astrophysics. The meeting was attended by fifty six pre-tenure faculty,
research scientists, postdoctoral scholars, and senior graduate students, as
well as eight former decadal survey committee members, who acted as
facilitators. The event was designed to educate early career astronomers about
the decadal survey process, to solicit their feedback on the role that early
career astronomers should play in Astro2020, and to provide a forum for the
discussion of a wide range of topics regarding the astrophysics career path.
This white paper presents highlights and themes that emerged during two days
of discussion. In Section 1, we discuss concerns that emerged regarding the
coming decade and the astrophysics career path, as well as specific
recommendations from participants regarding how to address them. We have
organized these concerns and suggestions into five broad themes. These include
(sequentially): (1) adequately training astronomers in the statistical and
computational techniques necessary in an era of "big data", (2) responses to
the growth of collaborations and telescopes, (3) concerns about the adequacy of
graduate and postdoctoral training, (4) the need for improvements in equity and
inclusion in astronomy, and (5) smoothing and facilitating transitions between
early career stages. Section 2 is focused on ideas regarding the decadal survey
itself, including: incorporating early career voices, ensuring diverse input
from a variety of stakeholders, and successfully and broadly disseminating the
results of the survey
Functional Complexity of the Axonal Growth Cone: A Proteomic Analysis
The growth cone, the tip of the emerging neurite, plays a crucial role in establishing the wiring of the developing nervous system. We performed an extensive proteomic analysis of axonal growth cones isolated from the brains of fetal Sprague-Dawley rats. Approximately 2000 proteins were identified at ≥99% confidence level. Using informatics, including functional annotation cluster and KEGG pathway analysis, we found great diversity of proteins involved in axonal pathfinding, cytoskeletal remodeling, vesicular traffic and carbohydrate metabolism, as expected. We also found a large and complex array of proteins involved in translation, protein folding, posttranslational processing, and proteasome/ubiquitination-dependent degradation. Immunofluorescence studies performed on hippocampal neurons in culture confirmed the presence in the axonal growth cone of proteins representative of these processes. These analyses also provide evidence for rough endoplasmic reticulum and reveal a reticular structure equipped with Golgi-like functions in the axonal growth cone. Furthermore, Western blot revealed the growth cone enrichment, relative to fetal brain homogenate, of some of the proteins involved in protein synthesis, folding and catabolism. Our study provides a resource for further research and amplifies the relatively recently developed concept that the axonal growth cone is equipped with proteins capable of performing a highly diverse range of functions
Longer and less overlapping food webs in anthropogenically disturbed marine ecosystems: confirmations from the past
The human exploitation of marine resources is characterised by the preferential removal of the largest species. Although this is expected to modify the structure of food webs, we have a relatively poor understanding of the potential consequences of such alteration. Here, we take advantage of a collection of ancient consumer tissues, using stable isotope analysis and SIBER to assess changes in the structure of coastal marine food webs in the South-western Atlantic through the second half of the Holocene as a result of the sequential exploitation of marine resources by hunter-gatherers, western sealers and modern fishermen. Samples were collected from shell middens and museums. Shells of both modern and archaeological intertidal herbivorous molluscs were used to reconstruct changes in the stable isotopic baseline, while modern and archaeological bones of the South American sea lion Otaria flavescens, South American fur seal Arctocephalus australis and Magellanic penguin Spheniscus magellanicus were used to analyse changes in the structure of the community of top predators. We found that ancient food webs were shorter, more redundant and more overlapping than current ones, both in northern-central Patagonia and southern Patagonia. These surprising results may be best explained by the huge impact of western sealing on pinnipeds during the fur trade period, rather than the impact of fishing on fish populations. As a consequence, the populations of pinnipeds at the end of the sealing period were likely well below the ecosystem's carrying capacity, which resulted in a release of intraspecific competition and a shift towards larger and higher trophic level prey. This in turn led to longer and less overlapping food webs
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