Search results for "first"

Locality of order-invariant first-order formulas

1998

A query is local if the decision of whether a tuple in a structure satisfies this query only depends on a small neighborhood of the tuple. We prove that all queries expressible by order-invariant first-order formulas are local.

Countable connected spaces and bunches of arcs in R3

2006

Abstract We investigate the images (also called quotients) of countable connected bunches of arcs in R 3 , obtained by shrinking the arcs to points (see Section 2 for definitions of new terms). First, we give an intrinsic description of such images among T 1 -spaces: they are precisely countable and weakly first countable spaces. Moreover, an image is first countable if and only if it can be represented as a quotient of another bunch with its projection hereditarily quotient (Theorem 2.7). Applying this result we see, for instance, that two classical countable connected T 2 -spaces—the Bing space [R.H. Bing, A connected countable Hausdorff space, Proc. Amer. Math. Soc. 4 (1953) 474], and th…

MAPPINGS OF FINITE DISTORTION: $L^n \log^{\alpha} L$ -INTEGRABILITY

2003

Recently, systematic studies of mappings of finite distortion have emerged as a key area in geometric function theory. The connection with deformations of elastic bodies and regularity of energy minimizers in the theory of nonlinear elasticity is perhaps a primary motivation for such studies, but there are many other applications as well, particularly in holomorphic dynamics and also in the study of first order degenerate elliptic systems, for instance the Beltrami systems we consider here.

Models of Data Quality

2018

The research proposes a new approach to data quality management presenting three groups of DSL (Domain Specific Language). The first language group uses concept of data object in order to describe data to be analysed, the second group describes the requirements on data quality, and the third group describes data quality management process. The proposed approach deals with development of executable quality specifications for each kind of data objects. The specification can be executed step-by-step according to business process descriptions, ensuring the gradual accumulation of data in the database and data quality verification according to the specific use case.

Model Transformation Languages and Their Implementation by Bootstrapping Method

2008

In this paper a sequence of model transformation languages L0, L1, L2 is defined. The first language L0 is very simple, and for this language it is easy to build an efficient compiler to C++. The next language L1 is an extension of L0, and it contains powerful pattern definition facilities. The last language L2 is of sufficiently high level and can be used for implementation of traditional pattern-based high level model transformation languages, as well as for the development of model transformations directly. For languages L1 and L2 efficient compilers have been built using the bootstrapping method: L1 to L0 in L0, and L2 to L1 in L1. The results confirm the efficiency of model transformat…

First trimester biochemical screening for Down's syndrome in singleton pregnancies conceived by assisted reproduction

2005

BACKGROUND: Serum biochemical markers [free betahCG (fbetahCG); pregnancy-associated plasma protein-A (PAPP-A)] used in first trimester Down's syndrome screening have not been fully investigated in pregnancies achieved by assisted reproduction techniques. We present data on pregnancies conceived by all types of assisted reproduction techniques, including pregnancies following ovum donation (OD) and a large sample by ICSI. METHODS: First trimester Down's syndrome screening was performed in 1054 normal singleton pregnancies: natural conception (n = 498), ovulation induction (OS, n = 97), IVF (n = 47), ICSI (n = 222) and OD (n = 190). RESULTS: No differences in maternal levels of fbetahCG and …

Computer simulations of bioequivalence trials: selection of design and analyte in BCS drugs with first-pass hepatic metabolism: linear kinetics (I).

2008

Modeling and simulation approaches are useful tools to assess the potential outcome of different scenarios in bioequivalence studies. The aim of this study is to propose a new and improved semi-physiological model for bioequivalence trial simulations and apply it for all BCS (Biopharmaceutic Classification System) drug classes with non-saturated first-pass hepatic metabolism. The semi-physiological model was developed in NONMEM VI to simulate bioequivalence trials. Parent drug and metabolite levels for both reference and test were simulated. Eight types of drugs (with high or low permeability and high or low solubility (class I to IV) and high or low intrinsic clearance) were considered in …

T110. FIRST EPISODE PSYCHOTIC PATIENTS WITH A HISTORY OF FREQUENT CANNABIS USE EXPRESS MORE POSITIVE SYMPTOMS AT ILLNESS ONSET THAN THOSE WHO NEVER U…

2018

Abstract Background Robust evidence has demonstrated that cannabis use increases the risk to develop psychotic disorders. However, a limited number of studies have investigated if and how cannabis use influences psychopathology profiles at first episode psychosis (FEP). Based on the evidence that dopamine dysfunction contributes to explain positive symptoms in psychosis, and that the main cannabis’ psychoactive component, Δ9-Tetrahydrocannabinol (THC), modulates the dopamine system, we hypothesise that: 1) positive symptoms at FEP are more common among psychotic patients who used cannabis compared with never users; 2) this association is a dose-response relationship. Methods We analyzed a s…

Retraction notice to “Relationship between dopamine D2 receptor occupancy, clinical response, and drug and monoamine metabolites levels in plasma and…

2012

Ketamine in acute phase of severe traumatic brain injury “an old drug for new uses?”

2021

AbstractMaintaining an adequate level of sedation and analgesia plays a key role in the management of traumatic brain injury (TBI). To date, it is unclear which drug or combination of drugs is most effective in achieving these goals. Ketamine is an agent with attractive pharmacological and pharmacokinetics characteristics. Current evidence shows that ketamine does not increase and may instead decrease intracranial pressure, and its safety profile makes it a reliable tool in the prehospital environment. In this point of view, we discuss different aspects of the use of ketamine in the acute phase of TBI, with its potential benefits and pitfalls.