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61.
Berit J. Sellevold 《American journal of physical anthropology》1980,53(4):569-572
The morphology of the mandibular torus was examined, and comparisons were made between a Medieval Norse skeletal population from Greenland and a 14th to 17th century Greenland Eskimo skeletal series. Three parameters were analyzed: degree of development (on a 4-point scale), position and length, and surface morphology according to the number of knobs, or lobuli. It was found that the Eskimos have a high frequency of weakly developed tori and no cases of the extreme development, while over 20% of the Norsemen had tori in the “extreme” category. The Norse torus was generally found to be longer than that of the Eskimos, and both groups exhibited a slight asymmetry between the sides, the torus on the left side tending to be longer and more forward in position than the right. A great difference was found in surface morphology. The Norse torus is in general very irregular, while the Eskimo torus is rather smooth. These differences are believed to be genetically determined. 相似文献
62.
63.
Oivind J Kanavin Berit Woldseth Egil Jellum Bjorn Tvedt Brage S Andresen Petter Stromme 《Journal of medical case reports》2007,1(1):1-5
Pulmonary emphysema and bronchiectasis in HIV seropositive patients has been described in the presence of injection drug use, malnutrition, repeated opportunistic infections, such as Pneumocytis jirovici pneumonia and Mycobacterium tuberculosis infection, and has been linked to the presence of HIV virus in lung tissue. Given the high burden of pulmonary infections and malnutrition among people living with HIV in resource poor settings, these individuals may be at increased risk of developing pulmonary emphysema, potentially reducing the long term benefit of antiretroviral therapy (ART) if initiated late in the course of HIV infection. In this report, we describe three HIV-infected individuals (one woman and two children) presenting with extensive pulmonary cystic disease. 相似文献
64.
Tone Bjordal Johansen Ingrid Olsen Merete Rus?s Jensen Ulf R Dahle Gudmund Holstad Berit Dj?nne 《BMC microbiology》2007,7(1):14
Background
Mycobacterium avium is an environmental mycobacterium that can be divided into the subspecies avium, hominissuis, paratuberculosis and silvaticum. Some M. avium subspecies are opportunistic pathogens for animals and humans. They are ubiquitous in nature and can be isolated from natural sources of water, soil, plants and bedding material. Isolates of M. avium originating from humans (n = 37), pigs (n = 51) and wild birds (n = 10) in Norway were examined by IS1245 and IS1311 RFLP using new and specific probes and for the presence of IS901 and ISMpa1 by PCR. Analysis and generation of a dendrogram were performed with the software BioNumerics. 相似文献65.
Rautengarten C Ebert B Ouellet M Nafisi M Baidoo EE Benke P Stranne M Mukhopadhyay A Keasling JD Sakuragi Y Scheller HV 《Plant physiology》2012,158(2):654-665
The cuticle is a complex aliphatic polymeric layer connected to the cell wall and covers surfaces of all aerial plant organs. The cuticle prevents nonstomatal water loss, regulates gas exchange, and acts as a barrier against pathogen infection. The cuticle is synthesized by epidermal cells and predominantly consists of an aliphatic polymer matrix (cutin) and intracuticular and epicuticular waxes. Cutin monomers are primarily C(16) and C(18) unsubstituted, ω-hydroxy, and α,ω-dicarboxylic fatty acids. Phenolics such as ferulate and p-coumarate esters also contribute to a minor extent to the cutin polymer. Here, we present the characterization of a novel acyl-coenzyme A (CoA)-dependent acyl-transferase that is encoded by a gene designated Deficient in Cutin Ferulate (DCF). The DCF protein is responsible for the feruloylation of ω-hydroxy fatty acids incorporated into the cutin polymer of aerial Arabidopsis (Arabidopsis thaliana) organs. The enzyme specifically transfers hydroxycinnamic acids using ω-hydroxy fatty acids as acyl acceptors and hydroxycinnamoyl-CoAs, preferentially feruloyl-CoA and sinapoyl-CoA, as acyl donors in vitro. Arabidopsis mutant lines carrying DCF loss-of-function alleles are devoid of rosette leaf cutin ferulate and exhibit a 50% reduction in ferulic acid content in stem insoluble residues. DCF is specifically expressed in the epidermis throughout all green Arabidopsis organs. The DCF protein localizes to the cytosol, suggesting that the feruloylation of cutin monomers takes place in the cytoplasm. 相似文献
66.
Berit Gehrke H. Peter Linder 《Proceedings. Biological sciences / The Royal Society》2009,276(1667):2657-2665
The composition of isolated floras has long been thought to be the result of relatively rare long-distance dispersal events. However, it has recently become apparent that the recruitment of lineages may be relatively easy and that many dispersal events from distant but suitable habitats have occurred, even at an infraspecific level. The evolution of the flora on the high mountains of Africa has been attributed to the recruitment of taxa not only from the African lowland flora or the Cape Floristic Region, but also to a large extent from other areas with temperate climates. We used the species rich, pan-temperate genera Carex, Ranunculus and Alchemilla to explore patterns in the number of recruitment events and region of origin. Molecular phylogenetic analyses, parametric bootstrapping and ancestral area optimizations under parsimony indicate that there has been a high number of colonization events of Carex and Ranunculus into Africa, but only two introductions of Alchemilla. Most of the colonization events have been derived from Holarctic ancestors. Backward dispersal out of Africa seems to be extremely rare. Thus, repeated colonization from the Northern Hemisphere in combination with in situ radiation has played an important role in the composition of the flora of African high mountains. 相似文献
67.
Bellstedt DU Pirie MD Visser JC de Villiers MJ Gehrke B 《American journal of botany》2010,97(7):e65-e68
? Premise of the study: We present a rapid and inexpensive alternative to DNA isolation for polymerase chain reaction (PCR) amplification from plants. ? Methods and Results: The method involves direct PCR amplification from material macerated in one buffer, followed by dilution and incubation in a second buffer. We describe the procedure and demonstrate its application for nuclear and plastid DNA amplification across a broad range of vascular plants. ? Conclusions: The method is fast, easy to perform, cost-effective, and consequently ideal for large sample numbers. It represents a considerable simplification of present approaches requiring DNA isolation prior to PCR amplification and will be useful in plant systematics and biotechnology, including applications such as DNA barcoding. 相似文献
68.
Berit Falkowska-Hansen Barbara Maria Grüner Petra Boukamp Axel Rethwilm 《Experimental cell research》2010,316(11):1885-1895
Many regenerative cells are label-retaining cells (LRCs) due to their ability to keep a DNA label over a prolonged time. Until recently, isolation of vital LRCs was hampered due to the necessary use of fixation methods. To circumvent this, we generated a lentiviral-(HIV-1) based vector expressing a Tet-Off controlled histone 2B-GFP (Tet-Off-H2B-GFP) reporter gene for the detection and isolation of viable LRCs. In initial experiments, the vector was successfully used to infect 2- and 3-dimensional tissue culture models. Infected cultures from skin and pancreatic cells showed a very tight regulation of H2B-GFP, were sensitive to minimal amounts of doxycycline (Dox) and had a stable transgenic expression over the time of this study. Our lentiviral vector represents a reliable and easy to handle system for the successful infection, detection and isolation of LRCs from various tissues in vitro, in vivo and ex vivo. 相似文献
69.
Berit Brands Morgana E. Vianna Ilse Seyfarth Georg Conrads & Hans-Peter Horz 《FEMS microbiology ecology》2010,71(1):157-167
We evaluated the impact of the base analogue inosine substituted at the 3'-terminus of broad-range 16S rRNA gene primers on the recovery of microbial diversity using terminal restriction fragment length polymorphism and clonal analysis. Oral plaque biofilms from 10 individuals were tested with modified and unmodified primer pairs. Besides a core overlap of shared terminal restriction fragments (T-RFs), each primer system provided unique information on the occurrence of T-RFs, with a higher number generally displayed with inosine primers. All clones sequenced were at least 99% identical to publicly available full-length sequences. Analysis of the corresponding primer-binding sites showed that most sequence types were 100% complementary to the unmodified primers so that the characteristic of inosine to bind with all four nucleotides was not crucial for the observed increase in microbial richness. Instead, differences in community compositions were correlated with the identity of the nearest-neighbor 3' of the primer-targeting region. By influencing the thermal stability of primer hybridization, this position may play a previously unrecognized role in biased amplification of 16S rRNA gene sequences. In conclusion, the combined use of inosine and unmodified primers enables the complementary retrieval of 16S rRNA gene types, thereby expanding the observed diversity of complex microbial communities. 相似文献
70.
Maria Isabel Veiga Pedro Eduardo Ferreira Berit Aydin Schmidt Ulf Ribacke Anders Bj?rkman Ales Tichopad José Pedro Gil 《PloS one》2010,5(8)