473 research outputs found
Causality, Information and Biological Computation: An algorithmic software approach to life, disease and the immune system
Biology has taken strong steps towards becoming a computer science aiming at
reprogramming nature after the realisation that nature herself has reprogrammed
organisms by harnessing the power of natural selection and the digital
prescriptive nature of replicating DNA. Here we further unpack ideas related to
computability, algorithmic information theory and software engineering, in the
context of the extent to which biology can be (re)programmed, and with how we
may go about doing so in a more systematic way with all the tools and concepts
offered by theoretical computer science in a translation exercise from
computing to molecular biology and back. These concepts provide a means to a
hierarchical organization thereby blurring previously clear-cut lines between
concepts like matter and life, or between tumour types that are otherwise taken
as different and may not have however a different cause. This does not diminish
the properties of life or make its components and functions less interesting.
On the contrary, this approach makes for a more encompassing and integrated
view of nature, one that subsumes observer and observed within the same system,
and can generate new perspectives and tools with which to view complex diseases
like cancer, approaching them afresh from a software-engineering viewpoint that
casts evolution in the role of programmer, cells as computing machines, DNA and
genes as instructions and computer programs, viruses as hacking devices, the
immune system as a software debugging tool, and diseases as an
information-theoretic battlefield where all these forces deploy. We show how
information theory and algorithmic programming may explain fundamental
mechanisms of life and death.Comment: 30 pages, 8 figures. Invited chapter contribution to Information and
Causality: From Matter to Life. Sara I. Walker, Paul C.W. Davies and George
Ellis (eds.), Cambridge University Pres
Verwerfungslinien in Organisationen - die Wirkung von Kontextfaktoren auf die Verbundenheit in Organisationen
Die Bedeutung von Commitment aus Sicht der Unternehmen bzw. der Organisationen wird in den letzten Jahren kontroversiell
diskutiert wird. Einerseits wird im Bereich der Personalressourcen ein wesentlicher zentraler Wettbewerbsvorteil
gesehen. Gleichzeitig können sehr verschiedene Formen von Beschäftigungsflexibilisierung beobachtet werden. Diese unterschiedlichen
Zugänge werden in diesem Beitrag aufgezeigt und die vielseitige Einbettung von Arbeit wie z. B. die
Wahrnehmung von Dispositionsmöglichkeiten im Hinblick auf Zeit, auf individuellen Handlungsspielräume oder auch
die erlebte soziale Gerechtigkeit präsentiert. All diese Dimensionen bergen das Potenzial in sich, sich als Trenn- bzw.
Verwerfungslinien (faultlines) in Organisationen darzustellen und damit auch Einfluss auf die Bindung in Organisationen
zu haben
Natriuretic peptide receptors on rat thymocytes: Inhibition of proliferation by atrial natriuretic peptide.
Because the thymus expresses the natriuretic peptides (NP) as well
as their respective receptors, an involvement of NP in the physiology
of this organ has been suggested. To evaluate functional aspects of NP
in the thymus, we looked for thymic cells bearing NP receptors (Npr).
Furthermore, the regulation of Npr expression by activation of cells
and the influence of NP on the proliferation of thymocytes was studied.
Expression of receptor messenger RNAs CmRNAs) was examined
by PCR and Northern blot. Existence of functional Npr was confirmed
by measurement of cGMP, the second messenger of NP. Proliferation
of thymocytes upon concanavalin A (Con A) stimulation was analyzed by incorporation of [“Hlthymidine. We report here that thymocytes express mRNAs for the three Npr, namely Npra, Nprb, and Nprc and
that activation of Npra and Nprb increases cGMP levels. Stimulation
of thymocytes with Con A (1 pg/ml, 48 h) resulted in an increase of
mRNA coding for Npra, the receptor specific for atria1 natriuretic
peptide (ANP) and brain natriuretic peptide. Nprb and Nprc receptor
expression was not altered under these conditions. In agreement with
these data only ANP, but not the C-type natriuretic peptide, elicited
increased cGMP response in Con A-stimulated cells. ANP inhibited
also the proliferation of Con A stimulated thymocytes, whereas C-type
natriuretic peptide did not show this effect. These results suggest that
ANP affects the complex mechanisms of thymocyte proliferation and
differentiation
Intranasal insulin to improve developmental delay in children with 22q13 deletion syndrome: an exploratory clinical trial
Background: The 22q13 deletion syndrome (Phelan–
McDermid syndrome) is characterised by a global
developmental delay, absent or delayed speech, generalised
hypotonia, autistic behaviour and characteristic
phenotypic features. Intranasal insulin has been shown to
improve declarative memory in healthy adult subjects and
in patients with Alzheimer disease.
Aims: To assess if intranasal insulin is also able to
improve the developmental delay in children with 22q13
deletion syndrome.
Methods: We performed exploratory clinical trials in six
children with 22q13 deletion syndrome who received
intranasal insulin over a period of 1 year. Short-term
(during the first 6 weeks) and long-term effects (after
12 months of treatment) on motor skills, cognitive
functions, or autonomous functions, speech and communication,
emotional state, social behaviour, behavioural
disorders, independence in daily living and education were
assessed.
Results: The children showed marked short-term
improvements in gross and fine motor activities, cognitive
functions and educational level. Positive long-term effects
were found for fine and gross motor activities, nonverbal
communication, cognitive functions and autonomy.
Possible side effects were found in one patient who
displayed changes in balance, extreme sensitivity to touch
and general loss of interest. One patient complained of
intermittent nose bleeding.
Conclusions: We conclude that long-term administration
of intranasal insulin may benefit motor development,
cognitive functions and spontaneous activity in children
with 22q13 deletion syndrome
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