Abstract is not available

In this thesis we study the (inverse) back-scattering problem for the Schr"odinger operator in $R^3$. We introduce the back-scattering transform $B(v)$ of a real-valued potential $vin C_0^infty(R^3)$, and prove that the back-scattering data associated to $v$ determine $B(v)$. Under the assumption that the Schr"odinger operator $H_v=-Delta +v$ has no eigenvectors in $L^2(R^3)$ it is shown that $B(v

We investigate a cooperative communications scheme with N parallel relays, where both the transmissions from the source to the relays and from the relays to the destination use fountain codes. Receiver for codes can accumulate mutual information, while traditional energy collection methods, such as repetition or cooperative space-time codes, only accumulate energy. As a consequence, using fountain

Thiol-disulfide oxidoreductases catalyze formation, disruption, or isomerization of disulfide bonds between cysteine residues in proteins. Much is known about the functional roles and properties of this class of redox enzymes in vegetative bacterial cells but their involvement in sporulation has remained unknown until recently. Two membrane-embedded thiol-disulfide oxidoreductases, CcdA and StoA/S

Conclusion. Our results show that average and poor oral hygiene and inadequate dental status are independent risk factors for oral and oropharyngeal squamous cell carcinoma ( OOSCC), irrespective of tobacco and alcohol consumption. Objective. To evaluate a possible relationship between oral cancer, oral hygiene, dental status, oral mucosal lesions and some lifestyle factors in a population- based

Pattern formation during development is controlled to a great extent by a small number of conserved signal transduction pathways that are activated by extracellular ligands such as Hedgehog, Wingless or Decapentaplegic. Genetic experiments have identified heparan sulphate proteoglycans (HSPGs) as important regulators of the tissue distribution of these extracellular signalling molecules. Several r

This study presents a predicted five-year reference interval for the outcome following repair of the median or ulnar nerve in adults. Forty-four patients were examined with the use of a recently introduced model instrument for documentation after nerve repair that includes "sensory", "motor", and "pain/discomfort" outcomes which together constitute a summarized "total score". Analysis of the "tota

Abstract is not available.

Greenhouse-grown clones of Viola tricolor were used to evaluate the importance of genetic effects on in vit ro pollen tube growth rate in relation to the influence of two environmental soil factors-pH and phosphorus content. After 1 mo in different soil treatments, individual pollen tube growth rate was affected by a genotype by phosphorus interaction, while it was unaffected by either main effect

We consider wireless systems with transmit and receive diversity. For reduction of complexity, we propose to use hybrid selection/maximal-ratio transmission at one link end, choosing L out of N antennas. We analyze the performance of such systems, giving analytical bounds and comparing them with computer simulations. Outage probability, symbol error probability, and capacity are shown. We demonstr

The first lifetime measurements have been performed for six levels of doubly ionized thorium, an important cosmochronometer in astrophysics for estimating the age of the Galaxy. The levels, belonging to the 5f(2), 5f7p, 7s7p, and 6d7p configurations of Th III, have been measured by the time-resolved laser-induced fluorescence method and compared with relativistic Hartree-Fock calculations includin

From 1975, when the Swedish Knee Arthroplasty Register (SKAR) started, until the end of 1997, 57,533 primary arthroplasties and revisions have been registered. Recently, the register underwent a comprehensive validation and update regarding revisions. We now report on general demographic and epidemiological data for the whole period and on the survivorship of arthroplasties performed in Sweden dur

Discussion of various historiographical approaches to film history.