268 research outputs found
Quantum Machine and SR Approach: a Unified Model
The Geneva-Brussels approach to quantum mechanics (QM) and the semantic
realism (SR) nonstandard interpretation of QM exhibit some common features and
some deep conceptual differences. We discuss in this paper two elementary
models provided in the two approaches as intuitive supports to general
reasonings and as a proof of consistency of general assumptions, and show that
Aerts' quantum machine can be embodied into a macroscopic version of the
microscopic SR model, overcoming the seeming incompatibility between the two
models. This result provides some hints for the construction of a unified
perspective in which the two approaches can be properly placed.Comment: 21 pages, 5 figures. Introduction and Conclusions improved, minor
corrections in several sections. Accepted for publication in Foundations of
Physic
Interpreting Quantum Particles as Conceptual Entities
We elaborate an interpretation of quantum physics founded on the hypothesis
that quantum particles are conceptual entities playing the role of
communication vehicles between material entities composed of ordinary matter
which function as memory structures for these quantum particles. We show in
which way this new interpretation gives rise to a natural explanation for the
quantum effects of interference and entanglement by analyzing how interference
and entanglement emerge for the case of human concepts. We put forward a scheme
to derive a metric based on similarity as a predecessor for the structure of
'space, time, momentum, energy' and 'quantum particles interacting with
ordinary matter' underlying standard quantum physics, within the new
interpretation, and making use of aspects of traditional quantum axiomatics.
More specifically, we analyze how the effect of non-locality arises as a
consequence of the confrontation of such an emerging metric type of structure
and the remaining presence of the basic conceptual structure on the fundamental
level, with the potential of being revealed in specific situations.Comment: 19 pages, 1 figur
Quantum Experimental Data in Psychology and Economics
We prove a theorem which shows that a collection of experimental data of
probabilistic weights related to decisions with respect to situations and their
disjunction cannot be modeled within a classical probabilistic weight structure
in case the experimental data contain the effect referred to as the
'disjunction effect' in psychology. We identify different experimental
situations in psychology, more specifically in concept theory and in decision
theory, and in economics (namely situations where Savage's Sure-Thing Principle
is violated) where the disjunction effect appears and we point out the common
nature of the effect. We analyze how our theorem constitutes a no-go theorem
for classical probabilistic weight structures for common experimental data when
the disjunction effect is affecting the values of these data. We put forward a
simple geometric criterion that reveals the non classicality of the considered
probabilistic weights and we illustrate our geometrical criterion by means of
experimentally measured membership weights of items with respect to pairs of
concepts and their disjunctions. The violation of the classical probabilistic
weight structure is very analogous to the violation of the well-known Bell
inequalities studied in quantum mechanics. The no-go theorem we prove in the
present article with respect to the collection of experimental data we consider
has a status analogous to the well known no-go theorems for hidden variable
theories in quantum mechanics with respect to experimental data obtained in
quantum laboratories. For this reason our analysis puts forward a strong
argument in favor of the validity of using a quantum formalism for modeling the
considered psychological experimental data as considered in this paper.Comment: 15 pages, 4 figure
Being Political in German Theatre and Performance: Anna Langhoff and Christoph Schingensief
Anna Langhoff and Christoph Schlingensief are two contemporary theatre makers who sit at opposite ends of the dramatic/postdramatic theatre divide. In that both artists see themselves as critics of western neoliberalism, their different approaches to theatre and performance invite a comparative study of ‘being political’. Langhoff’s neorealist plays and Schlingensief’s performance events both demonstrate the limits of liberal society’s capacity to deal with complex social problems. But how effective is each after the event? The paper uses Han Thiess Lehmann’s study of postdramatic theatre to compare the two performance styles.The conference was sponsored by A.D.S.A., the Department of Performance Studies, the School of Letters, Arts and Media, and the Faculty of Arts of the University of Sydney
Controlled expiration in mechanically-ventilated patients with chronic obstructive pulmonary disease (COPD)
In patients with severe chronic obstructive pulmonary disease (COPD), lung
emptying may be affected by flow limitation. We tested the hypothesis that
the airway compression leading to flow limitation can be counteracted by
controlling the expiratory flow. The effects of an external resistor on
lung emptying were studied in six patients with COPD, who were
mechanically ventilated whilst sedated and paralysed. Respiratory
mechanics were obtained during ventilatory support with and without the
resistor. Airway compression was assessed using the interruptor method.
For the study, a turbulent resistor was applied with the highest
resistance level that did not increase the end-expiratory lung volume. At
this resistance level, external positive end-expiratory pressure (PEEP)
was generated in all patients. As total PEEP levels remained unchanged at
both settings during the controlled expiration, the levels of intrinsic
PEEP were significantly decreased from 0.96+/-0.30 to 0.53+/-0.19 kPa
(mean+/-SD). Comparison of the expiratory flow-volume curves at both
settings revealed that, during the controlled expiration, the flows were
significantly decreased during the first 40% of the expired volume and
significantly increased during the last 60%. As the end-expiratory lung
volumes remained unchanged during both settings, these increments in flow
indicated a decrease in effective resistance. Airway compression was
observed during unimpeded expirations in all patients using the
interruptor method. During the application of the resistor, airway
compression was no longer detectable. In patients with chronic obstructive
pulmonary disease receiving ventilatory support, the application of an
external resistor could decrease effective expiratory resistance by
counteracting airway compression, without increments in end-expiratory
lung volume
Persistent bone disease in adult type 1 Gaucher disease despite increasing doses of enzyme replacement therapy
FWN – Publicaties zonder aanstelling Universiteit Leide
A critical assessment of SELDI-TOF-MS for biomarker discovery in serum and tissue of patients with an ovarian mass
<p>Abstract</p> <p>Background</p> <p>Less than 25% of patients with a pelvic mass who are presented to a gynecologist will eventually be diagnosed with epithelial ovarian cancer. Since there is no reliable test to differentiate between different ovarian tumors, accurate classification could facilitate adequate referral to a gynecological oncologist, improving survival. The goal of our study was to assess the potential value of a SELDI-TOF-MS based classifier for discriminating between patients with a pelvic mass.</p> <p>Methods</p> <p>Our study design included a well-defined patient population, stringent protocols and an independent validation cohort. We compared serum samples of 53 ovarian cancer patients, 18 patients with tumors of low malignant potential, and 57 patients with a benign ovarian tumor on different ProteinChip arrays. In addition, from a subset of 84 patients, tumor tissues were collected and microdissection was used to isolate a pure and homogenous cell population.</p> <p>Results</p> <p>Diagonal Linear Discriminant Analysis (DLDA) and Support Vector Machine (SVM) classification on serum samples comparing cancer versus benign tumors, yielded models with a classification accuracy of 71-81% (cross-validation), and 73-81% on the independent validation set. Cancer and benign tissues could be classified with 95-99% accuracy using cross-validation. Tumors of low malignant potential showed protein expression patterns different from both benign and cancer tissues. Remarkably, none of the peaks differentially expressed in serum samples were found to be differentially expressed in the tissue lysates of those same groups.</p> <p>Conclusion</p> <p>Although SELDI-TOF-MS can produce reliable classification results in serum samples of ovarian cancer patients, it will not be applicable in routine patient care. On the other hand, protein profiling of microdissected tumor tissue may lead to a better understanding of oncogenesis and could still be a source of new serum biomarkers leading to novel methods for differentiating between different histological subtypes.</p
Characterization of Human Glucocerebrosidase from Different Mutant Alleles
FWN – Publicaties zonder aanstelling Universiteit Leide
Mannose 6-phosphate-independent membrane association of cathepsin D, glucocerebrosidase, and sphingolipid-activating protein in HepG2 cells
FWN – Publicaties zonder aanstelling Universiteit Leide
- …