199 research outputs found
The rise and fall of star-formation in merging galaxy clusters
CIZA J2242.8+5301 (`Sausage') and 1RXS J0603.3+4213 (`Toothbrush') are two
low-redshift (), massive (), post-core
passage merging clusters, which host shock waves traced by diffuse radio
emission. To study their star-formation properties, we uniformly survey the
`Sausage' and `Toothbrush' clusters in broad and narrow band filters and select
a sample of and line emitters, down to a rest-frame equivalent
width ({\AA}). We robustly separate between H and higher redshift
emitters using a combination of optical multi-band (B, g, V, r, i, z) and
spectroscopic data. We build H luminosity functions for the entire
cluster region, near the shock fronts, and away from the shock fronts and find
striking differences between the two clusters. In the dynamically younger,
Gyr old `Sausage' cluster we find numerous () H emitters above a
star-formation rate (SFR) of M_{\sun} yr surprisingly located
in close proximity to the shock fronts, embedded in very hot intra-cluster
medium plasma. The SFR density for the cluster population is at least at the
level of typical galaxies at . Down to the same star-formation rate,
the possibly dynamically more evolved `Toothbrush' cluster has only
H galaxies. The cluster H galaxies fall on the SFR-stellar mass
relation for the field. However, the `Sausage' cluster has an
H emitter density times that of blank fields. If the shock passes
through gas-rich cluster galaxies, the compressed gas could collapse into dense
clouds and excite star-formation for a few Myr. This process ultimately
leads to a rapid consumption of the molecular gas, accelerating the
transformation of gas-rich field spirals into cluster S0s or ellipticals.Comment: Accepted for publication in MNRAS after minor referee report. 21
pages, 15 figures, 5 table
The Transcendentist Theory of Persistence
This paper develops an endurantist theory of persistence. The theory is built around one basic tenet, which concerns existence at a time â the relation between an object and the times at which that object is present. According to this tenet, which I call transcendentism, for an object to exist at a time is for it to participate in events that are located at that time. I argue that transcendentism is a semantically grounded and metaphysically fruitful. It is semantically grounded, insofar as a semantic analysis of our temporal talk favors it over rivals. It is metaphysically fruitful, insofar as the theory of persistence that can be built around it â the transcendentist theory of persistence, to give it a name â requires neither temporal parts nor the problematic commitments to which all extant forms of endurantism are committed, such as the possibility of extended simples or multilocation
Negative findings in electronic health records and biomedical ontologies: a realist approach
PURPOSEâA substantial fraction of the observations made by clinicians and entered into patient records are expressed by means of negation or by using terms which contain negative qualifiers (as in âabsence of pulseâ or âsurgical procedure not performedâ). This seems at first sight to present problems for ontologies, terminologies and data repositories that adhere to a realist view and thus reject any reference to putative non-existing entities. Basic Formal Ontology (BFO) and Referent
Tracking (RT) are examples of such paradigms. The purpose of the research here described was to test a proposal to capture negative findings in electronic health record systems based on BFO and RT.
METHODSâWe analysed a series of negative findings encountered in 748 sentences taken from 41 patient charts. We classified the phenomena described in terms of the various top-level categories and relations defined in BFO, taking into account the role of negation in the corresponding descriptions. We also studied terms from SNOMED-CT containing one or other form of negation. We then explored ways to represent the described phenomena by means of the types of representational units available to realist ontologies such as BFO.
RESULTSâWe introduced a new family of âlacksâ relations into the OBO Relation Ontology. The relation lacks_part, for example, defined in terms of the positive relation part_of, holds between a particular p and a universal U when p has no instance of U as part. Since p and U both exist, assertions involving âlacks_partâ and its cognates meet the requirements of positivity.
CONCLUSIONâBy expanding the OBO Relation Ontology, we were able to accommodate nearly all occurrences of negative findings in the sample studied
Inhibition of Listeria in cold-smoked salmon using liquid smoke and isoeugenol
Thesis (M.S.) University of Alaska Fairbanks, 2000Listeria monocytogenes is a foodborne pathogen, ubiquitous in nature and sometimes found in seafood. Cold-smoked salmon products have few barriers to inhibit pathogen growth. This study investigated the antilisterial effects of liquid smoke and the phenolic compound isoeugenol. Five commercial liquid smokes were tested 'in vitro' and the most inhibitory to Listeria monocytogenes ATCC 19115 and L. innocua ATCC 33090 was Charsol Supreme. Chum salmon samples (100-g each) were dipped for 15 seconds at varying concentrations of liquid smoke, processed, and analyzed for L. innocua. Liquid smoke concentrations of 60-100% reduced L. innocua by 3-logs in the final product. Dwell times of 15 seconds to 5 minutes using 60% liquid smoke gradually decreased listerial survival. Isoeugenol was antilisterial 'in vitro, ' but lacked synergism with liquid smoke in cold-smoked salmon. Charsol Supreme formed an antilisterial barrier in cold-smoked salmon, and may be a useful application to commercial products
Defendants with intellectual disability and autism spectrum conditions the perspective of clinicians working across three jurisdictions
The treatment of vulnerable defendants by criminal justice systems or correctional systems varies within and between countries. The purpose of this paper is to examine three legal jurisdictions â New South Wales in Australia; Norway; England and Wales â to understand the extent of variation in practice within the court systems for defendants with intellectual disabilities (ID) and/or autism spectrum conditions (ASC). Two of the jurisdictions had a process for screening in place, either in police custody or at court, but this was not universally implemented across each jurisdiction. All three jurisdictions had a process for
supporting vulnerable defendants through the legal system. Across the three jurisdictions, there was variation in disposal options from a mandatory care setting to hospital treatment to a custodial sentence for serious offences. This variation requires further international exploration to ensure the rights of defendants with ID or ASC are understood and safeguarde
Physical processes, their life and their history
Here, I lay the foundations of a high-level ontology of particulars whose structuring principles differ radically from the 'continuant' vs. 'occurrent' distinction traditionally adopted in applied ontology. These principles are derived from a new analysis of the ontology of âoccurringâ or âhappeningâ entities. Firstly, my analysis integrates recent work on the ontology of processes, which brings them closer to objects in their mode of existence and persistence by assimilating them to continuant particulars. Secondly, my analysis distinguishes clearly between processes and events, in order to make the latter abstract objects of thought (alongside propositions). Lastly, I open my ontological inventory to properties and facts, the existence of which is commonly admitted. By giving specific roles to these primitives, the framework allows one to account for static and dynamic aspects of the physical world and for the way that subjects conceive its history: facts account for the life of substances (physical objects and processes), whereas events enable cognitive subjects to account for the life story of substances
The Polygram, April 1917
Student newspaper of California Polytechnic State University, San Luis Obispo, CA.https://digitalcommons.calpoly.edu/studentnewspaper/1029/thumbnail.jp
Is Weak Supplementation analytic?
The research and writing of this paper was supported in part by a 2017-2018 Leverhulme Research Fellowship from the Leverhulme Trust.Mereological principles are often controversial; perhaps the most stark contrast is between those who claim that Weak Supplementation is analyticâconstitutive of our notion of proper parthoodâand those who argue that the principle is simply false, and subject to many counterexamples. The aim of this paper is to diagnose the source of this dispute. Iâll suggest that the dispute has arisen by participants failing to be sensitive to two different conceptions of proper parthood: the outstripping conception and the non-identity conception. Iâll argue that the outstripping conception (together with a specific set of definitions for other mereological notions), can deliver the analyticity of Weak Supplementation on at least one sense of âanalyticityâ. Iâll also suggest that the non-identity conception cannot do so independently of considerations to do with mereological extensionality.Publisher PDFPeer reviewe
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