Filetype
Lyapunov's second theorem is a standard tool for stability analysis of ordinary differential equations. Here we introduce a theorem which can be viewed as a dual to Lyapunov's result. From existence of a scalar function satisfying certain inequalities it follows that “almost all trajectories” of the system tend to zero. The scalar function has a physical interpretation as the stationary density of
Enhanced fibrinolytic reperfusion therapy may improve the outcome in embolic stroke, where ultrasound exposure has been shown to be one option. We recently verified that the fibrinolytic properties of streptokinase were modulated following ultrasound exposure of the molecule. We have now explored this possibility following ultrasound exposure of the reteplase molecule. The effects on clot lysis of
In several theories of the function of the cerebellum in motor control, the mossy-fiber-parallel fiber input has been suggested to provide information used in the control of ongoing movements whereas the role of climbing fibers is to induce plastic changes of parallel fiber (PF) synapses on Purkinje cells. From studies of climbing fibers during the last few decades, we have gained detailed knowled
The relative proportion of stroma lamellae and grana end membranes was determined from electron micrographs of 58 chloroplasts from 21 different plant species. The percentage of grana end membranes varied between 1 and 21% of the total thylakoid membrane indicating a large variation in the size of grana stacks. By contrast the stroma lamellae account for 20.3 +/- 2.5 (SD)% of the total thylakoid m
A novel artificial neural network heuristic (INN) for general constraint satisfaction problems is presented. extending a recently suggested method restricted to boolean variables. In contrast to conventional ANN methods, it employs a particular type of non-polynomial cost function, based on the information balance between variables and constraints in a mean-field setting. Implemented as an anneali
An integrated IT technology, characterized by a change in information support from a strong specialization towards greater integration has been introduced within the surveying company in Sweden. The aim of this study is to compare and describe effects of the transition to this new information technology in relation to job and organizational characteristics and effectiveness and well-being measures
A traumatic brain injury (TBI) extensively affects the injured person's daily life. Research based on the perspectives of people with TBI can increase understanding of the challenges they face and the possibility of supporting them in managing their lives. The aim of this study was to elucidate the meaning of living with TBI as narrated by the people with moderate or severe TBI. The data were coll
Objective and design Chemotaxis of neutrophils from blood to the inflammation process plays an important role in development of periodontal inflammation. The novel chemokine GRO alpha, also named CXCL1, is a strong chemoattractant for neutrophils. Data on production and regulation of GRO alpha by oral fibroblasts have not previously been presented. Materials and methods GRO alpha mRNA and protein
The protein alpha-synuclein is central to the pathophysiology of Parkinson's disease (PD) but its role in the development of neurodegeneration remains unclear. alpha-Synuclein-knockout mice develop without gross abnormality and are resistant to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), a mitochondrial inhibitor widely used to model parkinsonism. Here we show that differentiated human do
We propose a multidimensional continuum model for heterogeneous growth of biofilm systems with multiple species and multiple substrates. The new model provides a deterministic framework for the study of the interactions between several species and their effects on biofilm heterogeneity. It consists of a system of partial differential equations derived on the basis of conservation laws and reaction
Given an arbitrary real constant epsilon > 0, and a geometric graph G in d-dimensional Euclidean space with n points, O(n) edges, and constant dilation, our main result is a data structure that answers (1 + epsilon)-approximate shortest-path-length queries in constant time. The data structure can be constructed in O( n log n) time using O( n log n) space. This represents the first data structure t
Aggregation-prone proteins have been suggested to overwhelm and impair the ubiquitin/proteasome system (UPS) in polyglutamine (polyQ) disorders, such as Huntington's disease (HD). Overexpression of an N-terminal fragment of mutant huntingtin (N-mutHtt), an aggregation-prone polyQ protein responsible for HD, obstructs the UPS in cellular models. Furthermore, based on the accumulation of polyubiquit
To provide a basis for the interpretation of past climatic conditions from Quaternary leaf records, leaf carbon isotope (delta C-13) results are presented for 12 northern European dwarf-shrub, shrub and tree species growing across a network of 18 sites in northern Scandinavia. The role of micro-habitat (hummock/hollow) on carbon isotope trends is explored in addition to a comparison of the carbon
Using a simple hydrophobic/polar protein model, we perform a Monte Carlo study of the thermodynamics and kinetics of binding to a target structure for two closely related sequences, one of which has a unique folded state while the other is unstructured. We obtain significant differences in their binding behavior. The stable sequence has rigid docking as its preferred binding mode, while the unstru
Experimental stroke increases cell proliferation and neurogenesis in the subventricular zone (SVZ) and in the dentate gyrus subgranular zone (SGZ) in the adult mammalian brain. This study examined the effects of postischemic voluntary exercise (running wheel) and environmental enrichment on the SVZ and SGZ 1 week after focal cortical ischemia in adult spontaneously hypertensive rats. Immunohistoch
Commercial aircrafts need a high degree of fire protection for passenger safety. Brominated flame retardants (BFRs), including polybrominated diphenyl ethers (PBDEs), may be used for this purpose. Because PBDEs readily absorb to dust particles, aircraft crew and passengers may receive significant PBDEs exposure via inhalation. The aims of this work were to assess whether PBDEs could be found in ai
Nuclear spin relaxation is a powerful method for studying molecular dynamics at atomic resolution. Recent methods development in biomolecular NMR spectroscopy has enabled detailed investigations of molecular dynamics that are critical for biological function, with prominent examples addressing allostery, enzyme catalysis, and protein folding. Dynamic processes with similar correlation times are of
