Developmentally regulated changes in the glycoproteins of the equine embryonic capsule

The embryonic capsule, which covers the equine blastocyst after it loses its zona pellucida, is composed of mucin-like glycoproteins. In the present study, we investigated both macroscopic and molecular changes in the capsule during development. The weight of the capsule increased from day 11-12 of pregnancy and reached a maximum at about day 18, coinciding with the time during which the conceptus migrates extensively throughout the uterus. The sialic acid content of the capsule declined markedly from about day 16, the time of conceptus 'fixation' in the uterus, which suggests a unique developmentally regulated mechanism for the control of embryo mobility. These results lead us to propose that the capsule may have an anti-adhesion function in the developing conceptus, and that this effect could be regulated by the sugar side chains of the capsular glycoproteins. The glycosylation characteristics of the blastocyst coverings also underwent changes at about day 9 of pregnancy, which may be related to loss of the zona pellucida. An anti-capsule monoclonal antibody was raised and shown to recognize a tissue-specific antigen present only on the capsule and trophoblast. This antigen was present on the trophoblastic cells soon after the blastocyst is formed, reached a maximum concentration at about day 18, and was absent after day 22, coinciding with the disappearance of the capsule. Immunohistochemical studies indicate that the mucin-like capsular glycoproteins are secreted, at least in major part, by the trophoblast.(ABSTRACT TRUNCATED AT 250 WORDS)     

Slepian models for waves and wave-structure interaction

A regressive form of Slepian modelling was used to develop predictive models for the key variables associated with three quite different experimental data sets. The first data set provided a time series record of the surface elevation for a moderate random seaway. The second data set provided measurements of the wave elevation at the front of a finite draft deep water platform. This data set was significantly more nonlinear since the local wave field was amplified by the presence of the platform. The final data set dealt with the rate of wave run-up and this involved the derivative of the second data set. The results consistently illustrated the need to have an adequate number of events to use as the basis for the regression model. The study presents guidelines for selecting the initial crossing level which is crucial to the Slepian model development. Once the regression model has been established the model allows one to make predictions for other values of level crossing. It was found that the accuracy of those predictions depends on the accuracy of the initial regression process and that reasonable estimates can be obtained.     

Construction and expression of a modular gene encoding bacteriophage T7 RNA polymerase

Tachykinins inhibit salt appetite when applied intracranially in a number of brain regions and may function as endogenous inhibitors of sodium intake. To test the hypothesis that induced increases in salt appetite might involve disinhibition via a reduction in endogenous tachykinin expression, we used a semi-quantitative in situ hybridization analysis to investigate changes in brain areas expressing preprotachykinin-A (PPT-A) and preprotachykinin-B (PPT-B) mRNAs of rats after 1 day of sodium depletion (1d Na dep). PPT-A mRNA levels were detected in neurons of the olfactory tubercle (Tu), the nucleus of the olfactory tubercle (LOT), the dorsal and ventral caudate-putamen (d-CPu and v-CPu), the bed nucleus of the stria terminalis (BNST), the medial preoptic area (mPOA), the habenula (Hb) and the postero-dorsal part of the amygdala (MePD). PPT-B mRNA levels were measured in fundus striati (FStr), d-CPu, v-CPu, BNST, mPOA, dorsomedial hypothalamic nucleus (DMD), arcuate nucleus (Arc), central amygdaloid nucleus (CeL), basolateral amygdaloid nucleus (BLV), LOT, Hb and basal nucleus of Meynert (B). 1d Na dep reduced by 33-61% the mean number of PPT-A grains/cell in Tu, LOT, d-CPu, BNST, mPOA, Hb and MePD compared to control animals. Levels of PPT-B mRNA were not reduced as much by 1d Na dep, although statistically significant reductions of 26, 34 and 17% were found in v-CPu, BNST and B, respectively. These findings, therefore, support the hypothesis that endogenous tachykinins exert an inhibitory influence over sodium appetite.     

Data-driven and tool-supported elicitation of quality requirements in agile companies

Software Quality Journal - Quality requirements (QRs) are a key artifact needed to ensure the quality and success of a software system. Despite their importance, QRs rarely get the same degree of...     

The Displacement Calculus

If all dependent expressions were adjacent some variety of immediate constituent analysis would suffice for grammar, but syntactic and semantic mismatches are characteristic of natural language; indeed this is a, or the, central problem in grammar. Logical categorial grammar reduces grammar to logic: an expression is well-formed if and only if an associated sequent is a theorem of a categorial logic. The paradigmatic categorial logic is the Lambek calculus, but being a logic of concatenation the Lambek calculus can only capture discontinuous dependencies when they are peripheral. In this paper we present the displacement calculus, which is a logic of intercalation as well as concatenation and which subsumes the Lambek calculus. On the empirical side, we apply the new calculus to discontinuous idioms, quantification, VP ellipsis, medial extraction, pied-piping, appositive relativisation, parentheticals, gapping, comparative subdeletion, cross-serial dependencies, reflexivization, anaphora, dative alternation, and particle shift. On the technical side, we prove that the calculus enjoys Cut-elimination.     

Gold-Containing dendrimers: A new class of macromolecules

The synthesis of dendrimers possessing gold atoms on the surface or inside the internal layers is reported. They have been shown to be precursors to mixed gold-transition metal cluster-containing dendrimers, which represent a new class of hybrid materials. The latter species are rather soluble in common solvents and can be characterized by spectroscopic methods. Moreover, gold-containing dendrimers are useful for making gold nanoparticles, which have very interesting electronic, optical, and catalytic properties.     

Partitioning of trace inorganic elements in a coal-fired power plant equipped with a wet Flue Gas Desulphurisation system

The abatement capacity of trace inorganic elements was studied in a large Pulverized Coal Combustion (PCC) power plant equipped with a wet limestone Flue Gas Desulphurisation (FGD) system. High proportions of most elements were retained as fly ash as consequence of the efficiency of the electrostatic precipitator (ESP, 99.6% of fly ash) and slag (11%). The most volatile elements, such as S and F are retained by the FGD gypsum, and Cl by the filtered water; whereas the moderately volatile elements, As and B, are retained mainly by fly ash, reaching very high abatement efficiencies for these elements when considering the whole plant (>92%). Selenium and Hg are still retained by the whole system with relatively high proportions (89% and 67%); however a prominently proportion is emitted; Se (11%) and Hg (29%), attaining gaseous/PM rate at the emissions reaching 0.08 and 290, respectively. The gaseous emissions are below the limits according to the European directive 2001/80/EC for large combustion plants and the PRTR threshold values with the exception of Hg emissions and particulate Se, As, Zn, Cu, Ni, and Cr. Remediation actions to prevent and/or reduce the gaseous and PM emissions as well as the determination of leachable potential of trace inorganic pollutants retained in FGD gypsum, especially F in view of its disposal, are of significant relevance.