The parasite Toxoplasma gondii might harm the fetus if a woman is infected during pregnancy. IgG seroconversion and significant increase in IgG antibody amount in pregnancy indicates maternal ...infection. Presence of toxoplasma immunoglobulin M (IgM), immunoglobulin G (IgG) and low IgG avidity in a single serum sample indicates possible maternal infection, but positive toxoplasma IgM and low IgG avidity may persist for months and even years. We aimed to evaluate avidity development during pregnancy in a retrospective study. Serial blood samples from 176 pregnant women admitted to Oslo University Hospital 1993-2013 for amniocentesis because of suspected toxoplasma infection were included. Data were obtained from journals and laboratory records. The avidity method used was based on Platelia Toxo IgG assay. Mean maternal age at first serology was 29.9 years (SD 5.2, range 18-42). In 37 (21%) women only the avidity increased from low to high in < 3 months. In 139 (79%) the IgG avidity remained below the high threshold ≥ 3 months and within this group 74 (42%) women had stable low IgG avidity during the observation period. Median gestational age at first test was 10.6 weeks (range 4.6-28.7). Fetal infection was detected in four children, but none among children whose mother had stable low IgG avidity. The first antenatal toxoplasma serology should ideally be collected in early pregnancy and if stable values of toxoplasma IgM and low IgG-avidity are detected in a second sample after three to four weeks, the need for amniocentesis can be questioned.
Differential screening of a Gibberella fujikuroi cDNA library was used to successfully clone and identify genes involved in the pathway of gibberellin biosynthesis. Several cDNA clones that ...hybridized preferentially to a cDNA probe prepared from mycelium induced for gibberellin production were isolated and characterized. The deduced amino acid sequences of two (identical) clones contained the conserved heme-binding motif of cytochrome P450 monooxygenases (FXXGXXXCXG). One of these cDNA fragments was used as a homologous probe for the screening of a genomic library. A hybridizing 6.7-kb genomic SalI fragment was cloned into pUC19. The sequencing of this clone revealed that a second cytochrome P450 monooxygenase gene was closely linked to the first one. Since at least four cytochrome P450 monooxygenase-catalyzed steps are involved in the synthesis of gibberellins, chromosome walking was performed to find a further gene of this family or other genes involved in gibberellin pathway. Next to the two P450 monooxygenase genes, a putative geranylgeranyl diphosphate synthase gene, the copalyl diphosphate synthase gene, which is the first specific gene of the gibberellin pathway, and a third P450 monooxygenase gene were identified. These results suggest that at least some of the genes involved in the biosynthesis of gibberellins are closely linked in a gene cluster in G. fujikuroi, as has been recently found for other "dispensable" pathways in fungi.
The brain lacks lymph vessels and must rely on other mechanisms for clearance of waste products, including amyloid β that may form pathological aggregates if not effectively cleared. It has been ...proposed that flow of interstitial fluid through the brain’s interstitial space provides a mechanism for waste clearance. Here we compute the permeability and simulate pressure-mediated bulk flow through 3D electron microscope (EM) reconstructions of interstitial space. The space was divided into sheets (i.e., space between two parallel membranes) and tunnels (where three or more membranes meet). Simulation results indicate that even for larger extracellular volume fractions than what is reported for sleep and for geometries with a high tunnel volume fraction, the permeability was too low to allow for any substantial bulk flow at physiological hydrostatic pressure gradients. For two different geometries with the same extracellular volume fraction the geometry with the most tunnel volume had 36% higher permeability, but the bulk flow was still insignificant. These simulation results suggest that even large molecule solutes would be more easily cleared from the brain interstitium by diffusion than by bulk flow. Thus, diffusion within the interstitial space combined with advection along vessels is likely to substitute for the lymphatic drainage system in other organs.
Advantages of pre-injection grouting HOLTER, K. G; HOGNESTAD, H. O
Tunnels & Tunnelling International,
10/2010
OCT
Journal Article, Trade Publication Article
Barton et al (2003) demonstrates that injection pressures measured at the injection lance (the collar of the drillhole) in most cases do not correspond to the pressure of the grout in the actual ...ground. As long as there is a flow of grout, there is a significant drop of pressure in the immediate vicinity of the drillhole into the ground. Another important issue is to always have in mind that an injection operation is a cycle in which decisions are made with regards to specific criteria. These decisions are made at each step of the injection cycle. Therefore pre-injection is a type of work that requires continuous and experienced hands-on management during the works. The process of bleeding, in which the cement grains separate from the grout mix and clog the entrances to the fine joints, does not occur with a stable grout mix. For soil injection purposes one must consider closely which intended improvement effect and penetration mechanism that is planned when designing the grout mixes and the method. Four examples of soil improvement mechanisms are shown in figure 4. Liquid colloidal silica grout type consists of silica grains (SÌ02) in the nanometric scale in a colloidal solution in water. The typical grain size is 0.016 pm. Its viscosity is 5-6 m-Pa-s, which is slightly higher than water. These technical properties offer a unique technical performance in a number of injection situations. Colloidal silica, contrary to silicates and acrylates, is a completely non-toxic product, which makes it unique in terms of environmental friendliness and health and safety. Colloidal silica is a mineral grout designed for permanent longterm purposes, whereas silicates only can have a temporary function. The second injection stage with the low viscosity grout could therefore be targeted for the finer joints and the joints which were partially filled with clay and silt. The secondary fan was injected with a termination pressure of 25 bars, or approximately 100kg grout per m drillhole. Injection beyond a pressure of 25 bars with liquid colloidal silica usually showed signs of hydrofracturing.
A gene (cpd1) coding for the dimethylallyltryptophan synthase (DMATS) that catalyzes the first specific step in the biosynthesis of ergot alkaloids, was cloned from a strain of Claviceps purpurea ...that produces alkaloids in axenic culture. The derived gene product (CPD1) shows only 70% similarity to the corresponding gene previously isolated from Claviceps strain ATCC 26245, which is likely to be an isolate of C. fusiformis. Therefore, the related cpd1 most probably represents the first C. purpurea gene coding for an enzymatic step of the alkaloid biosynthetic pathway to be cloned. Analysis of the 3'-flanking region of cpd1 revealed a second, closely linked ergot alkaloid biosynthetic gene named cpps1, which codes for a 356-kDa polypeptide showing significant similarity to fungal modular peptide synthetases. The protein contains three amino acid-activating modules, and in the second module a sequence is found which matches that of an internal peptide (17 amino acids in length) obtained from a tryptic digest of lysergyl peptide synthetase 1 (LPS1) of C. purpurea, thus confirming that cpps1 encodes LPS1. LPS1 activates the three amino acids of the peptide portion of ergot peptide alkaloids during D-lysergyl peptide assembly. Chromosome walking revealed the presence of additional genes upstream of cpd1 which are probably also involved in ergot alkaloid biosynthesis: cpox1 probably codes for an FAD-dependent oxidoreductase (which could represent the chanoclavine cyclase), and a second putative oxidoreductase gene, cpox2, is closely linked to it in inverse orientation. RT-PCR experiments confirm that all four genes are expressed under conditions of peptide alkaloid biosynthesis. These results strongly suggest that at least some genes of ergot alkaloid biosynthesis in C. purpurea are clustered, opening the way for a detailed molecular genetic analysis of the pathway.
The parasite Toxoplasma gondii might harm the fetus if a woman is infected during pregnancy. IgG seroconversion and significant increase in IgG antibody amount in pregnancy indicates maternal ...infection. Presence of toxoplasma immunoglobulin M (IgM), immunoglobulin G (IgG) and low IgG avidity in a single serum sample indicates possible maternal infection, but positive toxoplasma IgM and low IgG avidity may persist for months and even years. We aimed to evaluate avidity development during pregnancy in a retrospective study. Serial blood samples from 176 pregnant women admitted to Oslo University Hospital 1993-2013 for amniocentesis because of suspected toxoplasma infection were included. Data were obtained from journals and laboratory records. The avidity method used was based on Platelia Toxo IgG assay. Mean maternal age at first serology was 29.9 years (SD 5.2, range 18-42). In 37 (21%) women only the avidity increased from low to high in < 3 months. In 139 (79%) the IgG avidity remained below the high threshold greater than or equal to 3 months and within this group 74 (42%) women had stable low IgG avidity during the observation period. Median gestational age at first test was 10.6 weeks (range 4.6-28.7). Fetal infection was detected in four children, but none among children whose mother had stable low IgG avidity. The first antenatal toxoplasma serology should ideally be collected in early pregnancy and if stable values of toxoplasma IgM and low IgG-avidity are detected in a second sample after three to four weeks, the need for amniocentesis can be questioned.
Sprayed concrete in combination with rock bolts is successfully being used for permanent rock support in tunnels. The main shortcoming is that sprayed concrete alone is unable to function as the ...permanent waterproofing with strict requirements on a dry interior tunnel surface. Final linings with precast or cast-in-place concrete with sheet membrane waterproofing represent an excessive structural design in hard rock conditions. The SUPERCON research project (Sprayed sUstainable PErmanent Robotized CONcrete) is currently aiming to improve the sprayed concrete technology to enable a permanent waterproof tunnel lining, based entirely on sprayed concrete.
Laboratory and full scale spray application testing include innovative mix designs with significantly reduced cement content. The effects of the use of fly ash and limestone powder binder replacement, hydration accelerators and high-performance shrinkage reducing agents as well as adding of polymer modification to the concrete mix and special steel fibres for the distribution of cracks in the hardened concrete were studied. A significant reduction of the autogenous shrinkage potential, and a reduction in the water transport (capillary suction and permeation) through cracks in the concrete using polymeric modification of the concrete was achieved. The use of shrinkage reducing measures in the mix, combined with anti-dryout measures on the sprayed concrete surface significantly reduce cracking risk. The research results so far indicate the feasibility of a waterproof sprayed concrete without a waterproofing membrane.
The material properties should provide sufficient support in hard rock and weakness zones, and provide long term durability under exposure to geomechanical, hydrogeological and geochemical conditions for the design service lifetime of the project. The need for a more robust technical solution with less sensitive details regarding construction has been a driving factor for developing a waterproof sprayed concrete. The material development process for the waterproof sprayed concrete in the SUPERCON research project has addressed shrinkage cracking and functional waterproof performance during application as main technical goals. In view of this research there was an obvious potential to reduce the cement content considering a lower requirement on the early age strength. The measured effects of the set accelerator, suggest that a low accelerator dosage of 3% contribute to a higher shrinkage compared to the higher dosage of 7% in either cases with both covered and uncovered specimens.
This study compared the prelinguistic vocal development of 30 9- month-old babies with unrepaired cleft palate and age-matched peers (N=15). Fewer of the babies with cleft palate had reached the ...canonical babbling stage (57 percent versus 93 percent) and had smaller consonant inventories. However, syllable types and length and number of vocalizations were similar for the two groups. (Contains references.) (Author/DB)
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