Sökresultat

In this paper we present two novel generic schemes for approximation algorithms for optimization NP-hard graph problems constrained to partial k-trees. Our first scheme yields deterministic polynomial-time algorithms achieving typically an approximation factor of k/log(1-is an element of)n, where k = polylog(n). The second scheme yields randomized polynomial-time algorithms achieving an approximat

Our aim was to quantify the intestinal metabolic fate of dietary alpha-ketoglutarate (AKG). Female pigs In = 6; 21 d old) were implanted with arterial, venous, portal and gastric catheters and an ultrasonic portal flow probe and fed a corn and soybean meal-based diet. On (t)he day of the experiment, the pigs received a 4-h intragastric infusion of sodium AKG at a rate equivalent to 0, 2.5, 5 or 10

The proliferation and differentiation of primitive hematopoietic cells is tightly controlled by a number of signaling pathways. Transient blockage or enhancement of these signaling pathways may provide a new approach to manipulate the proliferation and differentiation of primitive hematopoietic cells. Adenoviral vectors have in recent years emerged as powerful tools for transient gene expression i

We generated a mouse model with a conditional deletion of TGF-beta signaling in the neurons by crossing TGF-beta receptor I (T beta RI) floxed mice with neurofilament-H (NF-H) Cre mice. 35% of F1 conditional knockout (COKO) mice developed spontaneous squamous cell carcinomas (SCCs) in periorbital and/ or perianal regions. Transplantation of these tumors into athymic nude mice resulted in 62% tumor

Gene expression signatures consisting of tens to hundreds of genes have been found to be informative for different biological states. Recently, many computational methods have been proposed for biological interpretation of such signatures. However, there is a lack of methods for identifying cell signaling pathways whose deregulation result in an observed expression signature. We present a strategy

Surface proteins of Streptococcus pyogenes are important virulence factors. Here we describe a novel collagen-like surface protein, designated SclA (streptococcal collagen-like surface protein). The sclA gene was identified in silico using the Streptococcal Genome Sequencing Project with the recently identified protein GRAB as the probe. SclA has a signal sequence and a cell wall attachment region

Postural control ensures stability during both static posture and locomotion by initiating corrective adjustments in body movement. This is particularly important when the conditions of the support surface change. We investigated the effects of standing on a compliant foam surface using 12 normal subjects (mean age 26 years) in terms of: linear movements at the head, shoulder, hip and knee; EMG ac

Orientation can be difficult for nocturnal bird migrants at high northern latitudes because of the large changes of magnetic declinations, rapid longitudinal time-shifts experienced during a long-distance flight and the invisibility of stars during the polar summer. Both sunset cues as well as geomagnetic cues have been shown to be of great importance in the orientation system of Savannah sparrows

Background. Primary care doctors see patients from diverse cultural backgrounds and communication plays an important role in diagnosis and treatment. Communication problems can arise when patient and doctor do not share the same cultural background. Objective. The aim of this study was to examine how consultations with immigrant patients are understood by GPs and how GPs manage these consultation

Insect damage is a general problem that disturbs the growth of forests, causing economic losses and affecting carbon sequestration. Coarse-resolution data from satellites are potentially useful for national and regional mapping of forest damage, but the accuracy of these methods has not been fully examined. In this study, a method was tested for the mapping of defoliation in Scots pine [Pinus silv

The band alignment of ultrathin ZrO2 films of different thickness formed on Si(100) have been monitored with synchrotron radiation photoelectron spectroscopy and x-ray absorption spectroscopy. The films were deposited sequentially by way of metal-organic chemical-vapor deposition in ultrahigh vacuum. A significant decrease in the conduction band offset is found for increasing film thickness. It is

A new work organization was introduced in administrative surveying work in Sweden during 1998. The new work organization implied a transition to a client-centred team-based organization and required a change in competence from specialist to generalist knowledge as well as a transition to a new information technology, implying a greater integration within the company. The aim of this study was to f

Aims/hypothesis: The genetic architecture of model- derived parameters of beta cell function has never been assessed. Therefore, we estimated heritability (h(2)) for model- derived phenotypes of insulin secretion in twins. Methods: Thirty-three monozygotic (MZ) and 23 dizygotic (DZ) twin pairs from the Finnish Twin Cohort Study underwent OGTT (plasma glucose/C-peptide at 0, 30, 60, 90 and 120 min)

The probability distribution of the height of global maximum for a Gaussian random field evolving in time is studied. In particular, the effect of spreading is studied and the role of the wave kinematics is discussed. It is observed that taking into account time dynamics of spatial characteristics results in distributions different from those obtained for the static case. The results are illustrat