Malignant germ cell tumour in an infant vagina.

The mother of a 9-month-old female infant complained that her child was unable to pass urine at the same time noticing a mass protruding from the vaginal orifice.The infant had a single episode of vaginal bleeding.The primary concern of the mother was the inability of the daughter to micturate. Malignant germ cell tumour arising from an infant vagina is rare and accounts for about 3% of all paedriatic malignancies. These are also referred to as endodermal sinus tumours or yolk sac tumours, and are mostly the commonest form of infant vaginal malignancies encountered. A diagnosis of endodermal sinus tumour was established based on the histology and raised α-fetoprotein levels.These tumours had Schiller-Duval bodies which are primarily blood vessels surrounded by primordial germ cells and were periodic acid shift (PAS) positive diastase resistant hyaline globules which also stain positive with α- fetoprotein which is an important diagnostic feature. Tumours with high α-fetoprotein levels have a poorer prognosis. However, they respond satisfactorily to chemotherapy.

A comparison between floc morphology and the effluent clarity at a full-scale activated sludge plant using optical monitoring.

A charge-coupled device camera was used for the optical monitoring of activated sludge flocs and filaments, and the image analysis results were compared with the effluent clarity at a full-scale activated sludge plant during a three-month period. The study included a maintenance stoppage at the wastewater treatment plant, which was followed by a settling problem. Thus, the study presents the development of floc morphology from poor flocculation to good flocculation. In this case, the evolution of flocs was a slow process, and the optimum floc morphology was achieved before the purification results improved. To diagnose the cause of the settling problems using optical monitoring, four major factors were found to be relevant: the mean area of the flocs, the amount of small particles, the amount of filament and the shape parameters of the flocs. In this case, the settling problem was caused by dispersed growth based on the image analysis results. In conclusion, the method used has the potential for usefulness in the development of monitoring applications to predict plant performance and also to diagnose the causes of the settling problems.

Optical monitoring of activated sludge flocs in bulking and non-bulking conditions.

This study introduces a novel optical monitoring method to image and characterize activated sludge flocs and to study the dependency of sludge settling properties on the floc structure. The novel method can easily analyse thousands of particles in a short timeframe using the developed image analysis program. The main advantage of this method is its applicability for in situ use because the only required pre-treatment is sample dilution. This study tested real process samples from activated sludge plants treating wastewater from a pulp mill. The sludge samples were collected in bulking and non-bulking situations, and the image analysis results were compared to the settling speed of the samples. The structure of the activated sludge flocs was clearly different in bulking sludge situations as characterized by more fragile and elongated flocs. Additionally, excessive amounts of filamentous bacteria hold the flocs apart, hindering sludge settling. These results show that this method is suitable for studying and optimizing activated sludge processes.

Structural variation of tracheids in Norway spruce (Picea abies [L.] Karst.).

The orientation of cellulose microfibrils in the cell wall and the shape and the dimensions of the cells of earlywood of four Norway spruce (Picea abies [L.] Karst.) stems grown in Finland were studied by X-ray diffraction and optical microscopy. The average microfibril angle (MFA) decreased and the diameter of the cell increased rapidly up to rings 5-10 from the pith and remained at the same level after that. The average MFA close to the pith was over 20 degrees and decreased to about 8 degrees after ring 10 from the pith. The average diameter of the cells was 35 microm in the outer rings. The shape of the cross section of the lumen changed from circular to rectangular from the pith to the bark. The tracheid length increased also as a function of the distance from the pith. The thickness of the cell wall varied between 2.8 and 3.5 microm. Automatic cell lumen and cell wall recognition procedures were developed for the analysis of the images of the cross sections of the cells.