3,552 research outputs found
The Localization Hypothesis and Machines
No full textIn a recent article in 'Artificial Life', Chu and Ho suggested that Rosen's central result about the simulability of living systems might be flawed. This argument was later declared ''null and void'' by Louie. In this article the validity of Louie's objections are examined
Ca2+ signalling and homeostasis during colony initiation in Neurospora crassa
No full textCalcium is a highly versatile intracellular signal molecule that can regulate numerous
different cellular functions. In filamentous fungi there is evidence for it being
involved in regulating various processes, including spore germination, hyphal tip
growth, hyphal branching and conidiation. During colony initiation in the
filamentous fungus Neurospora crassa, conidia form germ tubes which are involved
in colony establishment, and conidial anastomosis tubes (CATs) which are involved
in generating fused networks of conidial germlings. The primary research aim of this
thesis was to analyze the role of Ca2+-signalling and homeostasis during colony
initiation in N. crassa.
Removal of Ca2+ from the growth medium showed that external Ca2+ was necessary
for CAT fusion and, more specifically, was required for CAT chemoattraction. Two
L-type Ca2+ channel blockers (verapamil and diltiazem) with different modes of
action were found to inhibit both conidial germination and CAT fusion in wild type
strains and CAT fusion was shown to be more sensitive to these two drugs. These
channel blockers were additionally found to inhibit Ca2+ uptake by conidial
germlings of the wild type expressing the aequorin Ca2+ reporter. However, the
channel blockers also, unexpectedly, raised the cytosolic free Ca2+ ([Ca2+]c) resting
level in these germlings suggesting that they did not just inhibit L-type Ca2+ activity.
The morphological phenotypes (conidial germination, hyphal extension rate,
conidiation and hyphal branching) of 22 mutants defective in different components
of their Ca2+-signalling and homeostasis machinery were characterized in order to
identify their possible roles of Ca2+ during colony initiation and development. The
∆cch-1 mutant lacking the CCH-1 L-type Ca2+ channel gene exhibited a reduction in
CAT fusion. CAT fusion was decreased even further in a double mutant (∆cch-1∆mid-1) suggesting that that the CCH-1 and MID-1 proteins operate in
combination during this process. Increased extracellular Ca2+ partially restored the
phenotypes of the ∆cch-1, ∆mid-1 smco-1 and ∆cch-1∆mid-1 mutants which is
consistent with CCH-1 and MID-1 being involved in Ca2+ uptake from the external
medium.
Calcium signatures following mechanical perturbation were successfully measured in
populations of conidial germlings using aequorin expressed in the wild type and in
deletion mutants (∆cch-1, ∆yvc-1, ∆fig-1) lacking different Ca2+ channels. The
removal of external Ca2+ completely abolished the [Ca2+]c increase in response to
mechanical perturbation and CCH-1 was found to partly contribute to this increase in
[Ca2+]c. Various Ca2+-sensitive dyes (Oregon green 488, Fluo-4 and Calcium
Green-1) were also tested to determine if they can be used to image [Ca2+]c at the
single cell and subcellular levels. Only Fluo-4 allowed the measurement of [Ca2+]c in
individual cells but the changes in dye fluorescence in response to changes in [Ca2+]c
were too small to be useful for imaging [Ca2+]c dynamics at the subcellular level. The
other two dyes underwent rapid compartmentalization in organelles when loaded into
germlings.
The plant antifungal proteins (defensins), MsDef1, MtDef4 and PAF were all found
to disrupt Ca2+ signaling/homeostasis in conidial germlings of N. crassa. They all
inhibited the [Ca2+]c increase and raised the resting level of [Ca2+]c in response to
mechanical perturbation. Analysis of an aequorin expressing mutant that was
defective in glucosylceramide synthase (∆gcs) showed that the effects of MsDef1
(but not MtDef4) on [Ca2+]c were mediated by the sphingolipid glucosylceramide.
All of the defensins tested were found to exhibit different potencies with regard to
their inhibitory effects on conidial germination and CAT fusion
MTO2000 Speedi-db
No full textLocuteurs dysphoniques enregistrés dans le service ORL du CHU de la Timone à Marseille entre 1995 et 200
Halocarbons in the atmosphere of the industrial-related Pearl River Delta region of China
No full textAuthor name used in this publication: Chu, K. W.Version of RecordPublishedVoR allowe
Retour d’expérience, CHU de Rouen confronté à une attaque en 2019
No full textInternational audienceIn this article, the author returns to the cyberattack against the Rouen University Hospital dating from 2019. It describes the measures that had to be put in place in order to respond to them and allow the proper functioning of the health system during this period of destabilization. For the author, a cyberattack is managed in six phases: 1. preparation for crisis management; 2. Identification of the cause and extent of the incident; 3. Compartmentalization and implementation of the action plan; 4. Remediation; 5. Restoration; 6. Feedback. For the author, the organization of the crisis unit is specific to each health institution but it is essential to train staff in the risks of a cyberattack.Dans cet article, l’auteur revient sur la cyberattaque à l’encontre du CHU de Rouen datant de 2019. Il décrit les mesures qui ont dû être mises en place afin de répondre à celles-ci et permettre le bon fonctionnement du système de santé durant cette période de déstabilisation. Pour l’auteur, une cyberattaque se gère en six phases : 1. la préparation de la gestion de crise ; 2. Identification de la cause et de l’étendue de l’incident ; 3. Le cloisonnement et la mise en place du plan d’action ; 4. La remédiation ; 5. La restauration ; 6. Le retour d’expérience. Pour l’auteur, l’organisation de la cellule de crise est propre à chaque établissement de santé mais il est indispensable de former le personnel aux risques d’une cyberattaque
On the Changing Political Structure of the Chu State: From an Archaeological Viewpoint
No full textThe emergence of centralised power and polity has long been a crucial problem in historical studies of Eastern Zhou society, and the conclusions of researchers on whether such centralised power was achieved in the state of Chu 楚 have been divided. One reason for this disagreement is due to the differing state of source materials for the Spring and Autumn and Warring States periods, making it difficult to grasp continuity in historical phenomena. In this article, the author re-examines the changing structure of the Chu state based on archaeological evidence from bronze vessels excavated in large quantities in the middle Yangzi River region that enables us to perceive temporal changes throughout the whole Eastern Zhou period. On the basis of archaeological analysis, the author draws three major conclusions. 1) The structure of production and distribution of bronze vessels in the Chu state changed drastically from the late Spring and Autumn period to early Warring States period, and a centralised system emerged by the middle of the Warring States period. 2) In the Spring and Autumn period, the Chu state distributed bronze vessels to the neighbouring polities as a strategy of indirect control in a way similar to that of the Western Zhou dynasty, although this strategy changed to direct domination over the entire middle Yangzi River region. 3) The structure of cemeteries of upper-ranking aristocrats changed through the middle of 5ᵗʰ century BC due to the emerging middle classes, who later became the bureaucrats providing the basis of centralised polity established in the middle Warring States period. Based upon these analyses, the author concludes that the political structure of the Chu state was gradually centralised through 5th century BC, which challenges the traditional views on the centralisation of the Chu polity represented by the drastic and short-term reformation by Wu Qi 吳起. This result calls for reconsideration of the “reformations” (變法) of Eastern Zhou societies from multiple points of view including both historical texts and archaeological materials
Espin dui chu sheng hou xiao shu xiao nao de Pujinshi xi bao de shu tu fa zhan zhi yan jiu
No full textLui, Nga Chu.Thesis M.Phil. Chinese University of Hong Kong 2014.Includes bibliographical references (leaves 84-92).Abstracts also in Chinese.Title from PDF title page (viewed on 12, December, 2016).Lui, Nga Chu
A Refuge for Jae-in Doe: Fugues in the Key of English Major
No full textA Refuge for Jae-in Doe: Fugues in the Key of English Major Author(s):Seo-Young Chu (see profile)Date:2017Subject(s):Feminism, Creative nonfiction, Asian American literature, Sonnets, Social justice, TraumaItem Type:EssayTag(s):#MeToo, Stanford, women in academia, early americanPermanent URL:http://dx.doi.org/10.17613/cp82-8f3
- …
