Kotimaisen järvi- ja merikalan dioksiinien, furaanien, dioksiinien kaltaisten PCB-yhdisteiden ja polybromattujen difenyylieettereiden pitoisuudet

EU-kalat -projekti toteutettiin, koska haluttiin saada tietoa kotimaisen kalan sisältämistä ympäristömyrkkypitoisuuksista. Tietoa päätettiin hankkia sekä Itämeren kalan että sisävesikalojen tärkeimmistä ympäristömyrkyistä: dioksiineista, joille oli asetettu EU:ssa enimmäispitoisuusraja, PCB-yhdisteistä, joiden sääntelyä EU:ssa osattiin odottaa, bromatuista difenyylieettereistä, joiden tiedettiin kertyvän kalaan sekä myös raskasmetalleista (julkaistaan erillisenä julkaisuna), joiden sääntelyä EU:ssa oli tarve tarkistaa. Suomen oli täytettävä myös ne edellytykset, jotka EU oli asettanut antaessaan Suomelle ja Ruotsille erityiskohtelun dioksiineja koskevassa lainsäädännössä. Lisäksi oli kiinnitettävä huomiota myös kotimaisen kalan sisältämien epäpuhtauksien aiheuttamiin seurauksiin kalastajille ja kalanjalostusteollisuudelle. Tutkimuksesta ilmeni, että dioksiinien ja PCB-yhdisteiden kertyminen kalaan on ennen kaikkea kalalajin ominaisuus. Ongelmakaloiksi jäivät lohi ja suurikokoinen silakka tässä järjestyksessä. Molemmista analysoitiin moninkertaisia pitoisuuksia dioksiineja enimmäispitoisuuteen (4 pg TEQ/g tuorepainoa) verrattuna. Sekä silakalla että lohella dioksiinipitoisuudet korreloivat iän mukana; mitä vanhempi kala sitä enemmän dioksiineja. Kaikki muut kotimaiset kalat paria poikkeuksellista tutkimustulosta lukuun ottamatta alittavat dioksiinille asetetun enimmäispitoisuusrajan. Myös kasvatetun kalan dioksiinipitoisuudet jäävät selvästi alle enimmäispitoisuusrajan

Ultraviolet asymptotics of scalar and pseudoscalar correlators in hot Yang-Mills theory

Inspired by recent lattice measurements, we determine the short-distance (a > omega >> pi T) asymptotics of scalar (trace anomaly) and pseudoscalar (topological charge density) correlators at 2-loop order in hot Yang-Mills theory. The results are expressed in the form of an Operator Product Expansion. We confirm and refine the determination of a number of Wilson coefficients; however some discrepancies with recent literature are detected as well, and employing the correct values might help, on the qualitative level, to understand some of the features observed in the lattice measurements. On the other hand, the Wilson coefficients show slow convergence and it appears uncertain whether this approach can lead to quantitative comparisons with lattice data. Nevertheless, as we outline, our general results might serve as theoretical starting points for a number of perhaps phenomenologically more successful lines of investigation.Comment: 27 pages. v2: minor improvements, published versio

Characteristics of C-4 photosynthesis in stems and petioles of C-3 flowering plants

Most plants are known as C-3 plants because the first product of photosynthetic CO2 fixation is a three-carbon compound. C-4 plants, which use an alternative pathway in which the first product is a four-carbon compound, have evolved independently many times and are found in at least 18 families. In addition to differences in their biochemistry, photosynthetic organs of C-4 plants show alterations in their anatomy and ultrastructure. Little is known about whether the biochemical or anatomical characteristics of C-4 photosynthesis evolved first. Here we report that tobacco, a typical C-3 plant, shows characteristics of C-4 photosynthesis in cells of stems and petioles that surround the xylem and phloem, and that these cells are supplied with carbon for photosynthesis from the vascular system and not from stomata. These photosynthetic cells possess high activities of enzymes characteristic of C-4 photosynthesis, which allow the decarboxylation of four-carbon organic acids from the xylem and phloem, thus releasing CO2 for photosynthesis. These biochemical characteristics of C-4 photosynthesis in cells around the vascular bundles of stems of C-3 plants might explain why C-4 photosynthesis has evolved independently many times

Prevalence of hyperuricemia and relation of serum uric acid with cardiovascular risk factors in a developing country

BACKGROUND: The prevalence of hyperuricemia has rarely been investigated in developing countries. The purpose of the present study was to investigate the prevalence of hyperuricemia and the association between uric acid levels and the various cardiovascular risk factors in a developing country with high average blood pressures (the Seychelles, Indian Ocean, population mainly of African origin). METHODS: This cross-sectional health examination survey was based on a population random sample from the Seychelles. It included 1011 subjects aged 25 to 64 years. Blood pressure (BP), body mass index (BMI), waist circumference, waist-to-hip ratio, total and HDL cholesterol, serum triglycerides and serum uric acid were measured. Data were analyzed using scatterplot smoothing techniques and gender-specific linear regression models. RESULTS: The prevalence of a serum uric acid level >420 μmol/L in men was 35.2% and the prevalence of a serum uric acid level >360 μmol/L was 8.7% in women. Serum uric acid was strongly related to serum triglycerides in men as well as in women (r = 0.73 in men and r = 0.59 in women, p < 0.001). Uric acid levels were also significantly associated but to a lesser degree with age, BMI, blood pressure, alcohol and the use of antihypertensive therapy. In a regression model, triglycerides, age, BMI, antihypertensive therapy and alcohol consumption accounted for about 50% (R2) of the serum uric acid variations in men as well as in women. CONCLUSIONS: This study shows that the prevalence of hyperuricemia can be high in a developing country such as the Seychelles. Besides alcohol consumption and the use of antihypertensive therapy, mainly diuretics, serum uric acid is markedly associated with parameters of the metabolic syndrome, in particular serum triglycerides. Considering the growing incidence of obesity and metabolic syndrome worldwide and the potential link between hyperuricemia and cardiovascular complications, more emphasis should be put on the evolving prevalence of hyperuricemia in developing countries

QCD and strongly coupled gauge theories : challenges and perspectives

We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.Peer reviewe