5,210 research outputs found
Double transverse spin asymmetry in the Drell-Yan process from Sivers functions
We show that the transverse double spin asymmetry (DSA) in the Drell-Yan
process contributed only from the Sivers functions can be picked out by the
weighting function
.
The asymmetry is proportional to the product of two Sivers functions from each
hadron . Using two sets of Sivers
functions extracted from the semi-inclusive deeply elastic scattering data at
HERMES, we estimate this asymmetry in the
Drell-Yan process which is possible to be performed in HESR at GSI. The
prediction of DSA in the Drell-Yan process contributed by the function
g_{1T}(x,\Vec k_T^2), which can be extracted by the weighting function
,
is also given at GSI.Comment: 6 latex pages, 2 figures, to appear in PR
Human-Centric Process-Aware Information Systems (HC-PAIS)
Process-Aware Information Systems (PAIS) support organizations in managing
and automating their processes. A full automation of processes is in particular
industries, such as service-oriented markets, not practicable. The integration
of humans in PAIS is necessary to manage and perform processes that require
human capabilities, judgments and decisions. A challenge of interdisciplinary
PAIS research is to provide concepts and solutions that support human
integration in PAIS and human orientation of PAIS in a way that provably
increase the PAIS users' satisfaction and motivation with working with the
Human-Centric Process Aware Information System (HC-PAIS) and consequently
influence users' performance of tasks. This work is an initial step of research
that aims at providing a definition of Human-Centric Process Aware Information
Systems (HC-PAIS) and future research challenges of HC-PAIS. Results of focus
group research are presented.Comment: 8 page
Successful thoracoscopic management of iatrogenic left subclavian arterial injury: a case report.
The subclavian artery at the thoracic outlet is in the deepest position of the thoracic cavity and is difficult to repair in this narrow space once injured, even if the surgery is converted to a thoracotomy. This article presents a successful left subclavian artery repair procedure at the thoracic outlet using a thoracoscopic approach, with a video demonstration, and describes its technical characteristics. The patient was planned for a left upper lobectomy through three-port thoracoscopic approach. Severe adhesions were found intraoperatively and an accidental left subclavian arterial injury occurred when dissecting the adhesions. We first clamped the proximal portion of the subclavian artery and then directly clamped the rupture site. Our first suture failed due to the limited suture angle and the mutual restriction between the needle holder and atraumatic vascular clamp. To freely control the needle holder, another assistant port was made in the seventh intercostal space (ICS). The arterial injury was finally successfully repaired using pledgetted suture. The operation time was 235 minutes and intraoperative blood loss was 800 mL. The pulsation of the left radial artery was normal postoperatively, and the patient was discharged on postoperative day 6. Appropriate strategies allow attempts to manage intraoperative hyperbaric arterial bleeding from the systemic circulation, such as bleeding caused by subclavian arterial injuries, by means of a thoracoscopic approach without conversion to thoracotomy
The Role of Regulated mRNA Stability in Establishing Bicoid Morphogen Gradient in Drosophila Embryonic Development
The Bicoid morphogen is amongst the earliest triggers of differential spatial pattern of gene expression and subsequent cell fate determination in the embryonic development of Drosophila. This maternally deposited morphogen is thought to diffuse in the embryo, establishing a concentration gradient which is sensed by downstream genes. In most model based analyses of this process, the translation of the bicoid mRNA is thought to take place at a fixed rate from the anterior pole of the embryo and a supply of the resulting protein at a constant rate is assumed. Is this process of morphogen generation a passive one as assumed in the modelling literature so far, or would available data support an alternate hypothesis that the stability of the mRNA is regulated by active processes? We introduce a model in which the stability of the maternal mRNA is regulated by being held constant for a length of time, followed by rapid degradation. With this more realistic model of the source, we have analysed three computational models of spatial morphogen propagation along the anterior-posterior axis: (a) passive diffusion modelled as a deterministic differential equation, (b) diffusion enhanced by a cytoplasmic flow term; and (c) diffusion modelled by stochastic simulation of the corresponding chemical reactions. Parameter estimation on these models by matching to publicly available data on spatio-temporal Bicoid profiles suggests strong support for regulated stability over either a constant supply rate or one where the maternal mRNA is permitted to degrade in a passive manner
The role of input noise in transcriptional regulation
Even under constant external conditions, the expression levels of genes
fluctuate. Much emphasis has been placed on the components of this noise that
are due to randomness in transcription and translation; here we analyze the
role of noise associated with the inputs to transcriptional regulation, the
random arrival and binding of transcription factors to their target sites along
the genome. This noise sets a fundamental physical limit to the reliability of
genetic control, and has clear signatures, but we show that these are easily
obscured by experimental limitations and even by conventional methods for
plotting the variance vs. mean expression level. We argue that simple, global
models of noise dominated by transcription and translation are inconsistent
with the embedding of gene expression in a network of regulatory interactions.
Analysis of recent experiments on transcriptional control in the early
Drosophila embryo shows that these results are quantitatively consistent with
the predicted signatures of input noise, and we discuss the experiments needed
to test the importance of input noise more generally.Comment: 11 pages, 5 figures minor correction
Sound as a Model of Time
Dieser Band dokumentiert künstlerische sowie theoretisch-wissenschaftliche Arbeiten, die aus einem von Sabine Sanio geleiteten Seminar des Wahlpflichtmoduls „Auditive Kultur: Recherche“ hervorgegangen sind. Das Thema des Seminars lautete „Sound als Zeitmodell“. Das Seminar fand im Wintersemester 2013/14 und im Sommersemester 2014 im Masterstudiengang Sound Studies an der Universität der Künste Berlin statt. Der Band besteht aus einem Text- und einem Bildteil. Im Textteil finden sich die Ergebnisse der theoretischen Auseinandersetzung mit dem Thema „Sound als Zeitmodell“. Der durch ausführliche Kommentare und Beschreibung ergänzte Bildteil dokumentiert die Ausstellung „KlangZeitGefühl“. Mit dieser Ausstellung, bei der die Seminarteilnehmer ihre künstlerischen Interpretationen des Seminarthemas zeigten, nahm der Masterstudiengang Sound Studies im Juni 2014 am Kunstfestival „48 Stunden Neukölln“ teil
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