973 research outputs found
Comparing hierarchies of total functionals
In this paper we consider two hierarchies of hereditarily total and
continuous functionals over the reals based on one extensional and one
intensional representation of real numbers, and we discuss under which
asumptions these hierarchies coincide. This coincidense problem is equivalent
to a statement about the topology of the Kleene-Kreisel continuous functionals.
As a tool of independent interest, we show that the Kleene-Kreisel functionals
may be embedded into both these hierarchies.Comment: 28 page
Acetazolamide in the treatment of acute mania - A case report
Several antiepileptic drugs are also being used in affective disorders. There are some hints that also the carbonic anhydrase inhibitor acetazolamide might be useful in the treatment of bipolar affective disorder. We report a 39-year-old male patient with a history of bipolar affective disorder who presented with his second manic episode. Acetazolamide was added to a low dose of valproic acid and to perazine. A marked decrease of the BRMAS score was achieved. The implications of this case are discussed
Differential treatment of bipolar disorder with old and new antiepileptic drugs
Although lithium remains the preferred medication for bipolar disorders, new investigations suggest that only 60 to 80% of patients have a good response with a classical presentation. The antiepileptics carbamazepine and valproate are important alternatives. Several studies have shown that lithium, carbamazepine and valproate are effective in pure mania. Mixed mania and rapid cycling respond, however, well to valproate. One disadvantage of carbamazepine is its enzyme inducing property with the consequence of a decrease of plasma levels of other psychotropic medications and a worsening of psychopathology. First data indicate a good antimanic and antidepressive efficacy of the new antiepileptic drug lamotrigine
Gain control in molecular information processing: Lessons from neuroscience
Statistical properties of environments experienced by biological signaling
systems in the real world change, which necessitate adaptive responses to
achieve high fidelity information transmission. One form of such adaptive
response is gain control. Here we argue that a certain simple mechanism of gain
control, understood well in the context of systems neuroscience, also works for
molecular signaling. The mechanism allows to transmit more than one bit (on or
off) of information about the signal independently of the signal variance. It
does not require additional molecular circuitry beyond that already present in
many molecular systems, and, in particular, it does not depend on existence of
feedback loops. The mechanism provides a potential explanation for abundance of
ultrasensitive response curves in biological regulatory networks.Comment: 10 pages, 5 figure
Dipole Field, Tune and Chromaticity Correction at the SPS: from Converter Tracking to Eddy Currents
Good control of key parameters like dipole field, tune and chromaticity is a basic requirement for fast cycle commissioning and for good beam transmission through the SPS ramp. The reproducibility of those parameters depends on power converter tracking, eddy currents and remnant fields. The new SPS control system was used to study some of the problems in the low energy ramp segment of the fixed target beam. A small modification of the function generation for the main converters is shown to reduce residual converter tracking errors by more than one order of magnitude. Tune and chromaticity corrections have been analyzed and summarized for different cycles, both for the ramp as well for the injection plateau where eddy current may play a significant role
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Environmental Measurement While Drilling System for Real-Time Field Screening of Contaminants
Sampling during environmental drilling is essential to fully characterize the spatial distribution and migration of subsurface contaminants. However, analysis of the samples is expensive and time-consuming: off-site laboratory analysis can take weeks or months. Real-time information on environmental conditions, drill bit location and temperature during drilling is valuable in many environmental restoration operations. This type of information can be used to provide field screening data and improved efficiency of site characterization activities. The Environmental Measurement-While-Drilling (EMWD) System represents an innovative blending of new and existing technology in order to obtain real-time data during drilling. The system consists of two subsystems. The down-hole subsystem (at the drill bit) consists of sensors, a power supply, a signal conditioning and transmitter board, and a radio-frequency (RF) coaxial cable. The up-hole subsystem consists of a battery pack/coil, pickup coil, receiver, and personal computer. The system is compatible with fluid miser drill pipe, a directional drilling technique that uses minimal drilling fluids and generates little to no secondary waste. In EMWD, downhole sensors are located behind the drill bit and linked by a high-speed data transmission system to a computer at the surface. Sandia-developed Windows{trademark}-based software is used for data display and storage. As drilling is conducted, data is collected on the nature and extent of contamination, enabling on-the-spot decisions regarding drilling and sampling strategies. Initially, the downhole sensor consisted of a simple gamma radiation detector, a Geiger-Mueller tube (GMT). The design includes data assurance techniques to increase safety by reducing the probability of giving a safe indication when an unsafe condition exists. The EMWD system has been improved by the integration of a Gamma Ray Spectrometer (GRS) in place of the GMT. The GRS consists of a sodium iodide-thallium activated crystal coupled to a photomultiplier tube (PMT). The output of the PMT goes to a multichannel analyzer (MCA).The MCA data is transmitted to the surface via a signal conditioning and transmitter board similar to that used with the GMT. The EMWD system is described and the results of the GRS field tests and field demonstration are presented
Charting service quality gaps
Some of the most influential models in the service management literature (Parasuraman et al., 1985; Grönroos, 1990) focus on the concept of service quality gap (SQG). Parasuraman et al. (1985) define a pioneering model with five SQGs, the concepts of which are amplified in Brogowicz et al.’s (1990) model. The latter has five types of encompassing gaps: information and feedback-related gaps; design-related gaps; implementation-related gaps; communication-related gaps; and customers’ perceptions and expectations related gaps. Additionally to this model amplification, other authors (e.g., Brown & Swartz, 1989) have pointed to relevant SQGs that have not been considered previously.
This paper integrates current models and a group of SQGs dispersed through the literature in a new comprehensive model. It draws a link between the model and the stages of a strategy process, emphasising the SQGs’ impact on the process and raising relevant research questions.FCT, FEUALG, UALG
On the computational content of Zorn's lemma
We give a computational interpretation to an abstract instance of Zorn's
lemma formulated as a wellfoundedness principle in the language of arithmetic
in all finite types. This is achieved through G\"odel's functional
interpretation, and requires the introduction of a novel form of recursion over
non-wellfounded partial orders whose existence in the model of total continuous
functionals is proven using domain theoretic techniques. We show that a
realizer for the functional interpretation of open induction over the
lexicographic ordering on sequences follows as a simple application of our main
results
Adaptive response and enlargement of dynamic range
Many membrane channels and receptors exhibit adaptive, or desensitized,
response to a strong sustained input stimulus, often supported by protein
activity-dependent inactivation. Adaptive response is thought to be related to
various cellular functions such as homeostasis and enlargement of dynamic range
by background compensation. Here we study the quantitative relation between
adaptive response and background compensation within a modeling framework. We
show that any particular type of adaptive response is neither sufficient nor
necessary for adaptive enlargement of dynamic range. In particular a precise
adaptive response, where system activity is maintained at a constant level at
steady state, does not ensure a large dynamic range neither in input signal nor
in system output. A general mechanism for input dynamic range enlargement can
come about from the activity-dependent modulation of protein responsiveness by
multiple biochemical modification, regardless of the type of adaptive response
it induces. Therefore hierarchical biochemical processes such as methylation
and phosphorylation are natural candidates to induce this property in signaling
systems.Comment: Corrected typos, minor text revision
Computational interpretations of analysis via products of selection functions
We show that the computational interpretation of full comprehension via two wellknown functional interpretations (dialectica and modified realizability) corresponds to two closely related infinite products of selection functions
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