Determinación quelatométrica de secantes en medio no acuoso

Se presenta una modificación de la técnica complejométrica utilizada para la determinación de secantes en forma directa en un medio no acuoso. Se emplea una mezcla de benceno-isopropanol-metil glicol en la relación 1/60/50. Se titula por retorno, usando soluciones de EDTA y cloruro de cinc, empleando negro de Eriocromo T como indicador y una solución reguladora de cloruro de amonio y amoníaco. El método es aplicado a la determinación de hierro, cobre, cobalto, cinc, manganeso, plomo, bario y calcio.A modification of the technique used for the complexometric determination of driers, for being used in non aqueous solutions is presented. The solvent used is a mixture of 1 part of bencene, 60 parts of isopropanol and 30 parts of methyl glicol.The back titration performed using EDTA solution, zinc chloride solution, Eriochrome black T as indicator, and a buffer solution of amonium hidroxide and amonium chloride. This method may be applied to the determination of iron, copper, cobalt, zinc, manganese, lead, barium and calcium

When Arm’s Length is Too Far:Relationship Banking over the Business Cycle

Using a novel way to identify relationship and transaction banks, we study how banks’ lending techniques affect funding to SMEs over the business cycle. For 21 countries we link the lending techniques that banks use in the direct vicinity of firms to these firms’ credit constraints at two contrasting points of the business cycle. We show that relationship lending alleviates credit constraints during a cyclical downturn but not during a boom period. The positive impact of relationship lending in an economic downturn is strongest for smaller and more opaque firms and in regions where the downturn is more severe

Indicatoren om dracht te meten in melk = Biomarkers in milk to predict pregnancy in dairy cattle

In this project the technical possibilities were investigated to use protein profiles in dairy milk as an indicator to improve fertility

Gensignalen voor voerefficiëntie en methaanemissie = Genomic selection to improve feed efficiency and reduce methane emission

There are many possibilities to breed for improved feed efficiency and reduced methane emission of dairy cattle. However, the results are not that reliable yet to be implemented directly

Mix design considerations of foamed bitumen mixtures with reclaimed asphalt pavement material

In the present work, a mix design parametric study was carried out with the aim of proposing a practical and consistent mix design procedure for foamed bitumen mixtures (FBMs). The mix design parameters that were adopted in the study are mixing and compaction water content (MWC), compaction effort using a gyratory compactor and aggregate temperature. This parametric study was initially carried out on FBMs with virgin limestone aggregate without reclaimed asphalt pavement (RAP) material and a mix design procedure was proposed. This proposed methodology was also found to apply to FBMs with RAP. A detailed consideration was also given to characterising the RAP material so as to understand its contribution to the mechanical properties of FBMs. Optimum MWC was achieved by optimising mechanical properties such as indirect tensile stiffness modulus and indirect tensile strength (ITS-dry and ITS-wet). A rational range of 75–85% of optimum water content obtained by the modified Proctor test was found to be the optimum range of MWC that gives optimum mechanical properties for FBMs. It was also found that the presence of RAP influenced the design foamed bitumen content, which means that treating RAP as black rock in FBM mix design is not appropriate. To study the influence of bitumen and water during compaction, modified Proctor compaction and gyratory compaction were employed on mixes with varying amounts of water and bitumen. By this, the work also evaluated the validity of the total fluid (water + bitumen) concept that is widely used in bitumen–emulsion-treated mixes, and found it not to be applicable

Induction of antibodies by Staphylococcus aureus nasal colonization in young children

AbstractIn order to develop novel antlstaphylococcal strategies, understanding the determinants of carriage and how humans respond to Staphylococcus aureus exposure is essential. Here, the primary S. aureus-specific humoral immune response and its association with nasal colonization was studied in young children. Sera from 57 colonized or non-colonized children, serially collected at birth and at 6, 14 and 24 months, were analysed for IgG, IgA and IgM binding to 19 staphylococcal proteins, using flow cytometry-based technology. The antibody responses showed extensive inter-individual variability. On average, the levels of antistaphylococcal IgA and IgM increased from birth until the age of 2 years (p <0.05), whereas the levels of IgG decreased (p <0.001). Placentally transferred maternal IgG did not protect against colonization. In colonized children, IgG and IgA levels for a number of proteins were higher than in non-colonized children. At both 14 and 24 months, the levels of IgG against chemotaxis inhibitory protein of S. aureus (at 24 months; median fluorescence intensity, 4928 vs. 24, p <0.05), extracellular fibrinogen-binding protein (987 vs. 604, p <0.05), and iron-responsive surface determinant H (62 vs. 5, p <0.05) were significantly higher in colonized children. The levels of IgA against CHIPS, IsdH and IsdA were higher (p <0.05). Therefore, CHIPS, Efb, IsdA and IsdH seem to play a role in nasal colonization of young children

Investigation of Thermal Stability Effects of Thick Hydrogenated Amorphous Silicon Precursor Layers for Liquid Phase Crystallized Silicon

The thermal stability of thick amp; 8776;4 amp; 8201; amp; 956;m plasma grown hydrogenated amorphous silicon a Si H layers on glass upon application of a rather rapid annealing step is investigated. Such films are of interest as precursor layers for laser liquid phase crystallized silicon solar cells. However, at least half day annealing at T amp; 8776;550 amp; 8201; C is considered to be necessary so far to reduce the hydrogen H content and thus avoid blistering and peeling during the crystallization process due to H. By varying the deposition conditions of a Si H, layers of rather different thermal stability are fabricated. Changes in the surface morphology of these a Si H layers are investigated using scanning electron microscopy and profilometry measurements. Hydrogen effusion, secondary ion mass spectrometry SIMS depth profiling, and Raman spectroscopy measurements are also carried out. In summary, amorphous silicon precursor layers are fabricated that can be heated within 30 amp; 8201;min to a temperature of 550 amp; 8201; C without peeling and major surface morphological changes. Successful laser liquid phase crystallization of such material is demonstrated. The physical nature of a Si H material stability instability upon application of rapid heating is studie

Copy number alterations in B-cell development genes, drug resistance, and clinical outcome in pediatric B-cell precursor acute lymphoblastic leukemia

Pediatric B-cell precursor acute lymphoblastic leukemia (BCP-ALL) is associated with a high frequency of copy number alterations (CNAs) in IKZF1, EBF1, PAX5, CDKN2A/B, RB1, BTG1, ETV6, and/or the PAR1 region (henceforth: B-cell development genes). We aimed to gain insight in the association between CNAs in these genes, clinical outcome parameters, and cellular drug resistance. 71% of newly diagnosed pediatric BCP-ALL cases harbored one or more CNAs in these B-cell development genes. The distribution and clinical relevance of these CNAs was highly subtype-dependent. In the DCOG-ALL10 cohort, only loss of IKZF1 associated as single marker with unfavorable outcome parameters and cellular drug resistance. Prednisolone resistance was observed in IKZF1-deleted primary high hyperdiploid cells (~1500-fold), while thiopurine resistance was detected in IKZF1-deleted primary BCR-ABL1-like and non-BCR-ABL1-like B-other cells (~2.7-fold). The previously described risk stratification classifiers, i.e. IKZF1plus and integrated cytogenetic and CNA classification, both predicted unfavorable outcome in the DCOG-ALL10 cohort, and associated with ex vivo drug cellular resistance to thiopurines, or L-asparaginase and thiopurines, respectively. This resistance could be attributed to overrepresentation of BCR-ABL1-like cases in these risk groups. Taken together, our data indicate that the prognostic value of CNAs in B-cell development genes is linked to subtype-related drug responses