277 research outputs found
The analogue of Izumi's Theorem for Abhyankar valuations
16 pagesA well known theorem of Shuzo Izumi, strengthened by David Rees, asserts that all the divisorial valuations centered in an analytically irreducible local noetherian ring are linearly comparable to each other. In the present paper we generalize this theorem to the case of Abhyankar valuations with archimedian value semigroup. Indeed, we prove that in a certain sense linear equivalence of topologies characterizes Abhyankar valuations with archimedian semigroups, centered in analytically irreducible local noetherian rings. Then we show that some of the classical results on equivalence of topologies in noetherian rings can be strengthened to include linear equivalence of topologies. We also prove a new comparison result between the Krull topology and the topology defined by the symbolic powers of an arbitrary ideal
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Sensemaking from the body: an enactive ethnography of rowing the Amazon
Drawing on real-time video, an audio journal, interviews and field notes from the first-ever attempt to scull the navigable Amazon, we explore the promise of carnal sociology to enrich our understanding of embodied organizational sensemaking. We investigate the body’s role in sensemaking from two vantage points: “of the body” and “from the body”. Using methodological and conceptual anchors provided in Wacquant’s carnal sociology, we contrast what each approach tells us about the nature and process of sensemaking. Doing so helps us outline a complementary approach to embodied sensemaking that attends to (1) how a “new way of seeing” the body as sentient, sedimented, situated, and capable of suffering enables a more holistic understanding of the role of embodiment in sensemaking; (2) the importance this then places on the “who” of sensemaking; and (3) carnal sociology’s broader methodological implications for organizational sensemaking
Good night, and good luck: perspectives on luck in management scholarship
It is not insignificant that seminal contributions to management scholarship have highlighted luck as an alternative explanation for performance differences between individuals and organizations. Yet it has rarely taken center-stage in scholarship. The principal purpose of this paper is to provide a systematic review of the application of luck in the management literature and in such foundation disciplines as economics, sociology, and psychology. Our analysis finds five common perspectives on luck: (a) luck as Attribution; (b) luck as Randomness; (c) luck as Counterfactual; (d) luck as Undeserved; and (e) luck as Serendipity. We outline various ways in which research on luck may be advanced along each of these perspectives, and develop an underexplored, sixth, perspective on (f) luck as Leveler to provide a possible solution to such issues as social inequality and (unwarranted) executive compensation.The first author is also grateful for financial support received from Cambridge Overseas Trust, Jesus College (Oxford), the Chiang Ching-kuo Foundation, and the Ministry of Education (Taiwan) that sponsored his PhD dissertation
Timing of infection and prior immunization with respiratory syncytial virus (RSV) in RSV-enhanced allergic inflammation
Respiratory syncytial virus (RSV) infection has been shown to be a risk factor for the development of allergy in humans and mice. The allergy-enhancing properties of RSV may be dependent on atopic background and an individual's history of RSV infection. We examined the influence of the timing of infection and prior inoculation with RSV in a mouse model of allergic asthma. Mice were sensitized to and challenged with ovalbumin (OVA) and were inoculated with RSV either before or during the sensitization or challenge period. One group of mice was inoculated with RSV both before sensitization to OVA and during challenge with OVA. Increased pulmonary expression of interleukin (IL)-4, IL-5, and IL-13 mRNA and aggravated alveolitis and hypertrophy of mucus-producing cells were observed only when OVA-sensitized mice were inoculated with RSV shortly before or during challenge with OVA. Despite protection against viral replication, prior inoculation with RSV did not abrogate RSV-enhanced, OVA-induced expression of T helper 2 (Th2) cytokines in the lung. In conclusion, inoculation with RSV enhances allergic disease only when the immune system has already been Th2-primed by the allergen (i.e., OVA). This RSV-enhanced allergy is not completely abrogated by prior inoculation with RSV
Resilience of beach grasses along a biogeomorphic successive gradient:Resource availability vs. clonal integration
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213623.pdf (publisher's version ) (Open Access
Serum IgA Responses against Pertussis Proteins in Infected and Dutch wP or aP Vaccinated Children: An Additional Role in Pertussis Diagnostics
BACKGROUND: Whooping cough is a respiratory disease caused by Bordetella pertussis, which induces mucosal IgA antibodies that appear to be relevant in protection. Serum IgA responses are measured after pertussis infection and might provide an additional role in pertussis diagnostics. However, the possible interfering role for pertussis vaccinations in the induction of serum IgA antibodies is largely unknown. METHODS/PRINCIPAL FINDINGS: We compared serum IgA responses in healthy vaccinated children between 1 and 10 years of age with those in children who despite vaccinations recently were infected with Bordetella pertussis. All children have been vaccinated at 2, 3, 4 and 11 months of age with either the Dutch whole-cell pertussis (wP) vaccine or an acellular pertussis (aP) vaccine and additionally received an aP booster vaccination at 4 years of age. Serum IgA responses to pertussis toxin (PT), filamentous heamagglutinin (FHA) and pertactin (Prn) were measured with a fluorescent multiplex bead-based immuno-assay. An ELISPOT-assay was used for the detection of IgA-memory B-cells specific to these antigens. Serum IgA levels to all pertussis vaccine antigens were significantly higher in infected children compared with healthy children. High correlations between anti-PT, anti-FHA or anti-Prn IgA and IgG levels were found in infected children and to some degree in wP primed children, but not at all in aP primed children. Highest numbers of IgA-pertussis-specific memory B-cells were observed after infection and generally comparable numbers were found after wP and aP vaccination. CONCLUSIONS: This study provides new insight in the diagnostic role for serum IgA responses against PT in vaccinated children. Since aP vaccines induce high serum IgG levels that interfere with pertussis diagnostics, serum IgA-PT levels will provide an additional diagnostic role. High levels of serum IgA for PT proved specific for recent pertussis infection with reasonable sensitivity, whereas the role for IgA levels against FHA and Prn in diagnosing pertussis remains controversial
Producing persuasive findings: Demystifying ethnographic textwork in strategy and organization research
Despite the importance and proliferation of ethnography in strategy and organization research, the central issue of how to present ethnographic findings has rarely been discussed. Yet, the narratives we craft to share our experience of the field are at the heart of ethnographic papers and provide the primary basis for our theorizing. In this article, we explain the “textwork” involved in writing persuasive findings. We provide an illustrative example of ethnographic data as it is recorded within fieldnotes and explain the necessary conceptual and writing work that must be done to render such data persuasive, drawing on published exemplars of ethnographic articles. This allows us to show how such texts, through various forms of writing and data representation, are transformed from raw fieldnotes to comprehensible findings. We conclude by asserting the value of these specifically ethnographic ways of presenting evidence, which are at odds with the canonical methods of data presentation in management studies
Linking Two Immuno-Suppressive Molecules: Indoleamine 2,3 Dioxygenase Can Modify HLA-G Cell-Surface Expression1
Nonclassical human leukocyte antigen (HLA) class I molecule
HLA-G and indoleamine 2,3 dioxygenase (INDO) in humans and
mice, respectively, have been shown to play crucial immunosuppressive
roles in fetal-maternal tolerance. HLA-G inhibits
natural killer and T cell function by high-affinity interaction with
inhibitory receptors, and INDO acts by depleting the surrounding
microenvironment of the essential amino acid tryptophan,
thus inhibiting T cell proliferation. We investigated whether
HLA-G expression and INDO function were linked. Working
with antigen-presenting cell (APC) lines and monocytes, we
found that functional inhibition of INDO by 1-methyl-tryptophan
induced cell surface expression of HLA-G1 by HLA-G1-
negative APCs that were originally cell-surface negative, and
that in reverse, the functional boost of INDO by high concentrations
of tryptophan induced a complete loss of HLA-G1 cell
surface expression by APCs that were originally cell-surface
HLA-G1-positive. This mechanism was shown to be posttranslational
because HLA-G protein cell contents remained unaffected
by the treatments used. Furthermore, HLA-G cell surface
expression regulation by INDO seems to relate to INDO function,
but not to tryptophan catabolism itself. Potentia
On the alleged simplicity of impure proof
Roughly, a proof of a theorem, is “pure” if it draws only on what is “close” or “intrinsic” to that theorem. Mathematicians employ a variety of terms to identify pure proofs, saying that a pure proof is one that avoids what is “extrinsic,” “extraneous,” “distant,” “remote,” “alien,” or “foreign” to the problem or theorem under investigation. In the background of these attributions is the view that there is a distance measure (or a variety of such measures) between mathematical statements and proofs. Mathematicians have paid little attention to specifying such distance measures precisely because in practice certain methods of proof have seemed self- evidently impure by design: think for instance of analytic geometry and analytic number theory. By contrast, mathematicians have paid considerable attention to whether such impurities are a good thing or to be avoided, and some have claimed that they are valuable because generally impure proofs are simpler than pure proofs. This article is an investigation of this claim, formulated more precisely by proof- theoretic means. After assembling evidence from proof theory that may be thought to support this claim, we will argue that on the contrary this evidence does not support the claim
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