Dynamics of daily height growth in Scots pine trees at elevated temperature and CO2

The aim of this study was to analyse and model the effects of elevated temperature and carbon dioxide concentration on daily height growth of 20-year-old Scots pines (Pinus sylvestris L.). The trees were grown with a low nitrogen supply in closed chambers with a factorial combination of two temperature regimes (ambient and elevated) and two carbon dioxide concentrations (ambient and twice ambient). The temperature elevation corresponded to the predicted increase at the site after a doubling in atmospheric CO₂. The height growth of Scots pines was first empirically studied in terms of its onset, cessation and duration, and the allocation of daily height growth within the growing period in 2000 and 2001, and then a model predicting daily height growth as a function of daily temperature and temperature sum was developed. The empirical results showed elevated temperature to be the dominant variable explaining variation in daily height growth. Elevated temperature also hastened both the onset and cessation of height growth, and the temperature sums for both of them were higher in the elevated than in the ambient temperature treatments. The daily variation in height growth could also be explained by the daily mean temperature in the model. Elevated CO₂ concentration had no effect on the onset, cessation or duration of height growth. The amount of height growth was not affected by any of the treatments.     

Characterisation of complete type II insertions in cloned segments of ribosomal DNA from Drosophila melanogaster

We have isolated cloned segments of ribosomal DNA that have EcoRI restrictable (type II) insertions in their 28 S genes. The type II insertions in these plasmids are homologous sequences and have three characteristic cleavage sites for EcoRI. One of these clones is unusual in that it has undergone a deletion of part of the 28 S gene at or near the site of the type II insertion. A second is unusual in that, in addition to the type II insertion in the rDNA, the transcribed spacer sequences are interrupted by an unidentified sequence. This sequence differs in its arrangement of restriction sites from the sequence that interrupts the transcribed spacer of cDm207 (Glover, 1977). The type II sequences in all these clones share homology with the unusually long ‘insertion’ that interrupts the 28 S gene of cDm207. We have re-examined the nature of the additional sequences linked to the type II sequences of cDm207 and find them to be related to type I rDNA insertion sequences.     

Rapid cloning and characterization of new chromosome 10 DNA markers by Alu element-mediated PCR

Alu element-mediated polymerase chain reaction is a strategy for rapidly cloning and mapping human DNA markers from mixed DNA sources. A novel primer homologous to the 3′ end of the human Alu repeat element provides the basis for preferential synthesis of human DNA fragments from human/rodent somatic cell hybrid DNA template. This approach has been used to isolate a series of new markers from chromosome 10. The Alu element-mediated PCR probes were regionally assigned on chromosome 10 by hybridization to Southern blots of Alu PCR-synthesized DNA derived from somatic cell hybrid template DNA. Alu element-mediated PCR is generally applicable and makes possible the analysis of complex genomes with a speed and sensitivity that has not been previously possible.     

Sequential Capecitabine/Temozolomide and Sunitinib Treatment in Patients With Metastatic Well-Differentiated Grade 1/Grade 2 Pancreatic Neuroendocrine Tumors

ObjectiveThe role of alternate sequential administration of sunitinib and capecitabine/temozolomide (CAPTEM) in metastatic pancreatic neuroendocrine tumors (PanNETs) remains unexplored. We thus aimed to analyze the efficacy and tolerability of this strategy in advanced grade 1/grade 2 PanNETs.MethodsIn total, data of 43 patients with metastatic PanNET were collected from a real-world database of a cancer center. Twenty-four patients were treated with sunitinib followed by CAPTEM (group 1), and 19 patients were treated with CAPTEM followed by sunitinib (group 2).ResultsTwenty-three patients were treated with first-line sunitinib or CAPTEM, and 20 patients were pretreated with somatostatin analog (SSA) or SSA in combination with transcatheter arterial chemoembolization. The objective response rate with first-line treatment was similar in both groups, whereas that with second-line treatment was higher in group 1 than in group 2, albeit with no significant differences (21.1% vs 5.3%, respectively; P = .205). Median progression-free survival (mPFS) for first-line and second-line treatments did not differ between the 2 groups (11 and 12 months vs 12 and 8 months, respectively). Following subgroup analyses, treatment with first-line sunitinib and sunitinib after pretreated SSA had a longer mPFS than that with second-line sunitinib after CAPTEM (11 months vs 8 months, respectively; P = .046), whereas treatment with first-line CAPTEM and CAPTEM after pretreated SSA had an mPFS similar to that of second-line CAPTEM after sunitinib treatment. CAPTEM and sunitinib had similar tolerability.ConclusionAlternating sunitinib and CAPTEM were well tolerated and associated with similar mPFS in grade 1/grade 2 PanNETs. However, larger prospective studies are required to investigate the efficacy of alternate sequential therapies for metastatic PanNET.     

Seed banks of grazed and ungrazed Baltic seashore meadows

Abstract. The seed banks of three grazed and three ungrazed seashore meadows were studied on the west coast of Finland. 8486 seedlings (mean 13 669 seedlings/m²) germinated from cold-treated samples (n = 343; depth = 10 cm). Most seedlings and species were monocots and perennials. The seed bank flora included 54 dicots vs. 28 monocots and 66 perennials vs. 16 annuals. The most abundant species were Juncus gerardii, Schoenoplectus tabernaemontani, Eleocharis uniglumis, Agrostis stolonifera, Juncus bufonius and Carex nigra, which made up 73% of the seed bank. Numbers of species and seedlings differed between elevation classes. Species richness was highest in elevation class 50–70 cm. The highest seed density occurred in class 20–50 cm. A model for size and species composition of the seed bank in relation to elevation is presented. The seed bank was larger and richer in species in the ungrazed than in the grazed sites, but not so in the upper elevations and closest to the open sea. Grazing reduced the size of the seed bank of Agrostis stolonifera, A. capillaris, Calamagrostis stricta, Elymus repens, Juncus bufonius, Limosella aquatica and Schoenoplectus tabernaemontani, but increased that of J. gerardii. 32 species germinated only from ungrazed samples and 11 species only from grazed ones. Multivariate classification resulted in nine sample groups. The ordination scatter was best explained by the flooding stress variables, elevation, the distance from the water line and the number of helophyte species in samples. 75 species were found both in the seed bank and in the vegetation, but there was a significant lack of resemblance (in the Mantel test) due to over-representation of some species. Eight species occurring only in the seed bank were mainly annuals or biennials (63%); those occurring only in the established vegetation (86 species) were mainly perennials (86%).