[Kirja-arvostelu]

Kirjallisuusarvostelu

Atmospheric concentrations of organic pollutants in the Arctic between 1993-2006

Continuous and comparable atmospheric monitoring programs to study the transport and occurrence of persistent organic pollutants (POPs) in the atmosphere of remote regions is essential to better understand the global movement of these chemicals and to evaluate the effectiveness of international control measures. Key results from four main Arctic research stations, Alert (Canada), Pallas (Finland), Storhofdi (Iceland) and Zeppelin (Svalbard/Norway), where long-term monitoring have been carried out since the early 1990s, are summarized. We have also included a discussion of main results from various Arctic satellite stations in Canada, Russia, US (Alaska) and Greenland which have been operational for shorter time periods. Using the Digital Filtration temporal trend development technique, it was found that while some POPs showed more or less consistent declines during the 1990s, this reduction is less apparent in recent years at some sites. In contrast, polybrominated diphenyl ethers (PBDEs) were still found to be increasing by 2005 at Alert with doubling times of 3.5 years in the case of deca-BDE. Levels and patterns of most POPs in Arctic air are also showing spatial variability, which is typically explained by differences in proximity to suspected key source regions and long-range atmospheric transport potentials. Furthermore, increase in worldwide usage of certain pesticides, e.g. chlorothalonil and quintozene, which are contaminated with hexachlorobenzene (HCB), may result in an increase in Arctic air concentration of HCB. The results combined also indicate that both temporal and spatial patterns of POPs in Arctic air may be affected by various processes driven by climate change, such as reduced ice cover, increasing seawater temperatures and an increase in biomass burning in boreal regions as exemplified by the data from the Zeppelin and Alert stations. Further research and continued air monitoring are needed to better understand these processes and its future impact on the Arctic environment.

Plant nuclear gene knockout reveals a role in plastid division for the homolog of the bacterial cell division protein FtsZ, an ancestral tubulin

Little is known about the division of eukaryotic cell organelles and up to now neither in animals nor in plants has a gene product been shown to mediate this process. A cDNA encoding a homolog of the bacterial cell division protein FtsZ, an ancestral tubulin, was isolated from the eukaryote Physcomitrella patens and used to disrupt efficiently the genomic locus in this terrestrial seedless plant. Seven out of 51 transgenics obtained were knockout plants generated by homologous recombination; they were specifically impeded in plastid division with no detectable effect on mitochondrial division or plant morphology. Implications on the theory of endosymbiosis and on the use of reverse genetics in plants are discussed.

Mso1p: A yeast protein that functions in secretion and interacts physically and genetically with Sec1p

The yeast Sec1p protein functions in the docking of secretory transport vesicles to the plasma membrane. We previously have cloned two yeast genes encoding syntaxins, SSO1 and SSO2, as suppressors of the temperature-sensitive sec1–1 mutation. We now describe a third suppressor of sec1–1, which we call MSO1. Unlike SSO1 and SSO2, MSO1 is specific for sec1 and does not suppress mutations in any other SEC genes. MSO1 encodes a small hydrophilic protein that is enriched in a microsomal membrane fraction. Cells that lack MSO1 are viable, but they accumulate secretory vesicles in the bud, indicating that the terminal step in secretion is partially impaired. Moreover, loss of MSO1 shows synthetic lethality with mutations in SEC1, SEC2, and SEC4, and other synthetic phenotypes with mutations in several other late-acting SEC genes. We further found that Mso1p interacts with Sec1p both in vitro and in the two-hybrid system. These findings suggest that Mso1p is a component of the secretory vesicle docking complex whose function is closely associated with that of Sec1p.

A Yeast t-SNARE Involved in Endocytosis

The ORF YOL018c (TLG2) of Saccharomyces cerevisiae encodes a protein that belongs to the syntaxin protein family. The proteins of this family, t-SNAREs, are present on target organelles and are thought to participate in the specific interaction between vesicles and acceptor membranes in intracellular membrane trafficking. TLG2 is not an essential gene, and its deletion does not cause defects in the secretory pathway. However, its deletion in cells lacking the vacuolar ATPase subunit Vma2p leads to loss of viability, suggesting that Tlg2p is involved in endocytosis. In tlg2Δ cells, internalization was normal for two endocytic markers, the pheromone α-factor and the plasma membrane uracil permease. In contrast, degradation of α-factor and uracil permease was delayed in tlg2Δ cells. Internalization of positively charged Nanogold shows that the endocytic pathway is perturbed in the mutant, which accumulates Nanogold in primary endocytic vesicles and shows a greatly reduced complement of early endosomes. These results strongly suggest that Tlg2p is a t-SNARE involved in early endosome biogenesis.

Talouskasvun edistäminen köyhyyspolitiikassa

Tutkielman aiheena on köyhyyden vähentäminen talouskasvua edistämällä. Tutkimuskysymys on, miten talouskasvu vaikuttaa köyhyyteen ja kuinka poliittisessa päätöksenteossa voitaisiin huomioida saatuja tutkimustuloksia. Tutkielmassa pyritään tunnistamaan, millaisella politiikalla talouskasvusta saisi köyhiä suosivampaa. Tutkimusmenetelmänä on kirjallisuuskatsaus. Tutkielman johtopäätöksinä todetaan, että talouskasvu keskimäärin hyödyttää köyhiä, mutta valittu empiirinen malli vaikuttaa tuloksiin. Tässä tutkielmassa mukana olleissa empiirisissä malleissa talouskasvu keskimäärin hyödytti köyhiä korkeintaan saman verran kuin muuta väestöä. Tulevaisuudessa köyhyyspolitiikan pitäisi perustua enemmän eriarvoisuuden vähentämiseen kuin talouskasvun edistämiseen. Tällä hetkellä on kuitenkin olemassa alueita, joissa eriarvoisuuden vähentämisellä ei tulla saavuttamaan niin merkittävää köyhyyden vähentymistä kuin talouskasvun avulla on mahdollista. Eriarvoisuus on tekijä, joka vaikuttaa yksilön mahdollisuuksiin ansaita ja kerätä varallisuutta. Lisäksi se on tekijä, joka vaikuttaa siihen, kuinka hyvin valtio onnistuu vähentämään köyhyyttä. Talouskasvun lisäksi valtiossa pitää olla sopivat olosuhteet, jotta köyhyys vähenisi, pelkkä talouskasvu ei ole riittävää. Eriarvoisuuden vähentäminen on keino, jolla talouskasvusta saadaan enemmän irti köyhyyden vähentämiseksi