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Tadpole impact on periphytic algae was estimated with an exclosure experiment in the field. Algae growth on control (exposed) and experimental (netted-in) perspex plates was measured in 12 ponds in 1991 and 8 in 1993. An index of snail (Lymnea and Planorbis) presence in the ponds was used to correct their effect. Grazing pressure (difference in amount of algae between control and experimental plat
RhoH is a small GTPase expressed only in the hematopoietic system. With the use of mice with targeted disruption of the RhoH gene, we demonstrated that RhoH is crucial for thymocyte maturation during DN3 to DN4 transition and during positive selection. Furthermore, the differentiation and expansion of DN3 and DN4 thymocytes in vitro were severely impaired. These defects corresponded to defective T
Long-distance dispersal of seeds is an important process in metapopulation dynamics and in plant migrations, but at the same time extremely difficult to observe or quantify directly. If seed dispersal ability were related to attributes of seeds or motherplants, long-distance seed dispersal would be predictable by indirect approximation using easy-to-measure traits. Seed size has been suggested to
Subarctic aerosol was sampled during July 2007 at the Abisko Research Station Stordalen field site operated by the Royal Swedish Academy of Sciences. Located in northern Sweden at 68 degrees latitude and 385 m above sea level (m asl), this site is classified as a semicontinuous permafrost mire. Number density, size distribution, cloud condensation nucleus properties, and chemical composition of th
Analogues of the irreversible protease inhibitors TPCK and TLCK have been synthesized and tested as inhibitors of the bacterial cysteine protease IdeS excreted by Streptococcus pyogenes. Eight compounds were identified as inhibitors of IdeS in an in vitro assay. The most potent compounds contained an aldehyde function, thus acting as efficient reversible inhibitors, nitrile and azide derivatives s
Homogenates of human blood platelets, but not of red blood cells, have been found to stimulate lipoprotein lipase activity only when assayed against an emulsified triglyceride substrate sonicated for a short period of time. The degree of stimulation was inversely related to the time of sonication of the substrate. Using chylomicrons as substrate no stimulation of lipoprotein lipase activity by pla
Clinical data are presented on a 30-year-old male with normal early development (4-5 years) but subsequent progressive impairment of psychomotor functions. He has marked kyphoscoliosis and talipes calcaneo-valgus. The organs appear normal and the patient can walk unaided and feed himself although he does not recognize his parents. He has normal fundi oculi. Biochemical data show an absence of muco
Acute myeloid leukemia (AML) with inv(16)(p13q22) or the variant t(16;16)(p13;q22), is strongly associated with the FAB subtype M4Eo. A high incidence of CNS involvement was reported in the 1980s, but otherwise little is known about the pattern of extamedullary leukemia (EML) manifestations in this AML type. We have compiled clinical and cytogenetic data on 27 consecutive AML cases with inv(16)/t(
This paper presents an overview of how circuit models can be used for analysing wave propagation in stratified structures. Relatively complex structures can be analysed using models which are accessible to undergraduate students. Homogeneous slabs are modelled as transmission lines, and thin sheets between the slabs are modelled as lumped elements. It is seen that electric material properties act
A review and expansion of the fundamental processes of the vapor-liquid-solid (VLS) growth mechanism for nanowires is presented. Although the focus is on nanowires, most of the concepts may be applicable to whiskers, nanotubes, and other unidirectional growth. Important concepts in the VLS mechanism such as preferred deposition, supersaturation, and nucleation are examined. Nanowire growth is feas
In pre-industrial society, choosing a marriage partner was a crucial process, and especially so for landowners. This study focuses on social aspects of mate selection in five rural parishes in southern Sweden between 1829 and 1894, using an individual-level database containing information on a large number of marriages and the social origins of the marrying couple regardless of whether they were b
Digital holography has some desirable properties for refractometry of microscopic objects since it gives phase and amplitude information of an object in all depths of focus from one set of exposures. We show that the amplitude part of the image can be used to observe how the Becke lines move between different depths of focus and hence determine whether an object has a higher or a lower index of re
The Svecofennian Domain of the Fennoscandian Shield constitutes a considerable volume of Palaeoproterozoic crustal growth, 2.1-1.86 Ga ago, in between the Archaean craton in the NE and the 1.85-1.65 Ga Transscandinavian Igneous Belt (TIB) in the south and west. The Bergslagen area is a classical ore province located in the southwestern part of the Svecofennian Domain of southcentral Sweden. Its no
Recombinant Saccharomyces cerevisiae harbouring the xylose reductase (XR) gene XYL1 from Pichia stipitis was grown in anoxic chemostat culture at two different dilution rates. At each dilution rate a transient experiment, encompassing a shift in the sugar content of the medium from glucose to glucose plus xylose was performed. The steady states at the beginning and the end of the transients were c
The Clp protease is conserved among eubacteria and most eukaryotes, and uses ATP to drive protein substrate unfolding and translocation into a chamber of sequestered proteolytic active sites. The main constitutive Clp protease in photosynthetic organisms has evolved into a functionally essential and structurally intricate enzyme. The model Clp protease from the cyanobacterium Synechococcus consist
We studied CSF-tau and CSF-Abeta42 in 16 patients with mild cognitive impairment (MCI) who at follow-up investigations 6-27 months later had progressed to Alzheimer's disease (AD) with dementia. For comparison, we studied 15 age-matched healthy individuals. At baseline, 14/16 (88%) of MCI patients had high CSF-tau and/or low CSF-Abeta42 levels. These findings show that these CSF-markers are abnorm
This paper describes a method to digitize high-resolution physical properties of annually laminated lake sediments. We modified a water-acetone epoxy exchange method in order to preserve all the fine structural details that varved sequences provide. By applying sediment microstratigraphical investigations (X-ray radiography, SEM) and semi-automatic image analysis, we were able to establish detaile
