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An hypothesis is presented that provitamin D (dehydrocholesterol and/or ergosterol) can act as a UV-B receptor in plants and algae. We also propose that the proportions between provitamins D, previtamins D, and vitamins D (D2 and D3), after calibration, can be used to evaluate UV-B exposure of phytoplankton and terrestrial vegetation. This is the final, accepted and revised manuscript of this art

Reception of partially correlated fields by two closely coupled electrical dipoles is discussed as a function of load impedances and open-circuit correlations. Two local maxima of the power may be achieved for two different load impedances, but in those cases the output correlations are high. Choosing the loads to give zero output correlations is possible for almost any real-valued open-circuit co

Mitochondrial DNA (mtDNA) is the traditional workhorse for reconstructing evolutionary events. The frequent use of mtDNA in such analyses derives from the apparent simplicity of its inheritance: maternal and lacking bi-parental recombination. However, in hybrid zones, the reproductive barriers are often not completely developed, resulting in the breakdown of male mitochondrial elimination mechanis

Polystyrene (PS) blends containing a dispersed phase of either polyamide-6 (PA-6) or polyamide-12 (PA-12) were compatibilized by additions of 1, 3, or 5 wt % poly(styrene-graft-ethylene oxide). The graft copolymers were found to have a stabilizing effect on the domain sizes. Weight average radii of PA-6 domains in compression molded samples were reduced by a factor of 5 with 3 wt % graft copolymer

Background: The electrocardiographic (ECG) diagnosis of acute myocardial infarction (MI) should be improved. This might be done either by regarding all 24 aspects (both positive and negative leads), or a subset hereof (e.g. 19-lead ECG), of the conventional 12-lead ECG or by using additional electrodes. The purpose of this study was to investigate the accuracy of the different ECG methods in diagn

Protein self-association may be detrimental in biological systems, but can be utilized in a controlled fashion for protein crystallization. It is hence of considerable interest to understand how factors like solution conditions prevent or promote aggregation. Here we present a computational model describing interactions between protein molecules in solution. The calculations are based on a molecul

Newly emerged females of the European pine sawfly, Neodiprion sertifer Geoffroy (Hymenoptera: Diprionidae), were placed on pine twigs in the field and their behavior was recorded. Twenty to 25% of the females attracted wild males and mated on the day of release. One-third to one-half of these females remained and oviposited, while the rest disappeared from their twigs after mating. The mating freq

The extreme polymorphism of the vertebrate major histocompatibility complex (Mhc) is famous for protecting hosts against constantly evolving pathogens. Mate choice is often evoked as a means of maintaining Mhc variability through avoidance of partners with similar Mhc alleles or preference for heterozygotes. Evidence for these two hypotheses mostly comes from studies on humans and laboratory mice.

Biomass provides the largest reduction of carbon dioxide (CO2) emission when it replaces coal, which is the dominating fuel in heat and electricity production in Poland. One means of replacing coal with biomass is to co-fire biofuels in an existing coal-fired boiler. This paper presents an analysis of the strengths and weaknesses of co-firing biofuels in Poland with respect to technical, environme

As a second major result we show how to combine the path cover technique with LCA solutions for dags with small depth [9]. Our algorithm attains the best known upper time bound for this problem of O(n 2.575). However, most notably, the algorithm performs better on a vast amount of input dags, i.e. dags that do not have an almost linear-sized subdag of extremely regular structure. Finally, we appl

Health risks associated with heterocyclic amines in cooked foods have been discussed and analysed since the presence of these food mutagens was first detected. Intake, metabolism, carcinogenicity and epidemiology are important parameters in the risk assessment of heterocyclic amines. It is very difficult to determine the human intake of heterocyclic amines, as the content in cooked meat is highly

CONTEXT: Tuberculosis (TB) is an increasing global problem, despite effective drug therapies. Access to TB therapy during conflict situations has not been studied. OBJECTIVE: To determine the effect of irregular TB treatment due to an armed conflict in Guinea-Bissau, West Africa. DESIGN, SETTING, AND PATIENTS: Ongoing retrospective cohort study conducted in the capital city of Bissau among 101 pat

Huntington's disease (HD) is caused by a polyglutamine expansion in the protein huntingtin and is characterized by intraneuronal inclusions and widespread neuronal death at the late stage of the disease. In research, most of the emphasis has been on understanding the cell death and its mechanisms. Until recently, it was believed that the vast majority, if not all, of the symptoms in HD are a direc