Image analysis of sludge aggregates obtained at preliminary treatment of sewage.

The results of wastewater treatment by Al and Fe salts and by electrocoagulation with aluminum electrodes are discussed and interpreted. Those processes used alone or combined with biological treatment, were analyzed for 50 and 90% removal of phosphates. Scanning electron microscopy (SEM) of the resulting sludge from three coagulation processes defined the perimeter P and area A of 129-142 differently sized objects in each contrast-enhanced image. Plots of lg A against lg P revealed that the analyzed sludge samples were made of self-similar aggregates-flocs with fractal characteristics. The slope of 'log plots' was used to determine surface fractal dimension Da, which was extrapolated to volumetric fractal dimension Dv. Dv was applied in a quantitative description of sludge aggregates-flocs. Aggregates-flocs of sludge obtained by Al ions (pre-polymerized Al and electrocoagulation) were characterized by higher values of Dv in comparison with sludge obtained by iron salts. The structure of {Al(OH)(3)} and {Fe(OH)(3)} aggregate-flocs was graphically simulated to determine the effect of size distribution and Dv on sweep flocculation and sludge separation and dehydration. Phosphate removal efficiency of 50% occurred at low ratios of Al:P and Fe:P. Adsorption-charge neutralization was suggested during coagulation with pre-polymerized coagulants, and sweep flow mechanism during electrocoagulation.

Prediction of fat, muscle and value in Norwegian lamb carcasses using EUROP classification, carcass shape and length measurements, visible light reflectance and computer tomography (CT).

One hundred and twenty carcasses were sampled to compare different techniques or methods for prediction of lamb carcass composition and value. Four methods that are used at the Norwegian Meat Research Centre, Animalia, were selected. These were the basic EUROP classification, the advanced EUROP classification using carcass shape and length measurements, visible light reflectance probing (GP) and Computer Tomography (CT). The different technologies were tested using an iterative approach, selecting calibration and validation data sets from the 120 carcasses randomly, where 90 carcasses were used for calibration, and 30 for validation. The best prediction models were obtained using CT, with respect to prediction error and correlation between predicted and measured value of carcass fat and muscle (in kg), and value (in NOK). Due to high cost and low operating speeds of CT, optical probing (GP) may be the second best solution of the technologies used in this study, combined with a CT dissection reference as an alternative to manual dissection.

Prevalence and symptomatology of depression in older people living in institutions in England and Wales.

BACKGROUND: Epidemiological studies have shown that depression is common in institutional settings. However, the symptomatology of depression in this group has not been compared to those living in the community. AIMS: To estimate the prevalence of depression and depressive symptomatology in participants living in institutions and compare these to people living in other settings. METHOD: The Medical Research Council Cognitive Function and Ageing Study (MRC CFAS) is a population-based cohort comprising 13,004 individuals aged 65 and above, from five sites across England and Wales. Following screening, a stratified random sub-sample of 2,640 participants received the Geriatric Mental State (GMS) examination of whom 340 resided in institutions. Diagnoses of depression were made using the Automated Geriatric Examination for Computer-assisted Taxonomy system (AGECAT). RESULTS: The prevalence of depression in those living in institutions was 27.1% (95% CI 17.8-36.3) compared to 9.3% (95% CI 7.8-10.9) in those living at home. Symptoms relating to depressed mood, severity of illness (e.g. wishing to be dead, future looking bleak) and some non-specific symptoms were more common in those living in residential homes. Depression was significantly associated with younger age (P = 0.002) and high functional disability (P = 0.009) in those living in institutions. CONCLUSIONS: Consistent with previous estimates, depression was highly prevalent in institutions, particularly in younger individuals with severe functional impairment. Those in institutions report considerably more symptoms of depression. Finding interventions which address these symptoms might improve quality of life for people in institutions, irrespective of formal diagnoses.

Psychometric properties of the state part of the Spielberger State-Trait Anxiety Inventory (STAI) in geriatric patients.

BACKGROUND: A conspicuously high score on the state part of the State-Trait Anxiety Inventory (STAI) has been observed among geriatric inpatients who are neither demented nor critically ill; 43% of them had a sumscore that, according to Spielberger's criteria, would reflect clinically relevant anxiety symptoms. OBJECTIVES: To explore the reasons for this high score. METHODS: 101 geriatric inpatients and 68 healthy controls of similar age, living at home and recruited through senior citizen centres participated in a controlled cross-sectional study. RESULTS: High item-scores were more frequent on the symptom-negative items than on the symptom-positive items. Multi-group factor analysis produced two factors termed 'well-being' and 'nervousness', which had a moderate correlation (0.61). The intercept was much higher on 'well-being' than on 'nervousness', showing that a lack of well-being contributes significantly to the high score on the STAI. This confounds the sumscore. However, the geriatric inpatients nevertheless had a high score on the factor 'nervousness'. Female controls scored higher than males on both factors, whereas among the geriatric patients neither age nor gender related to them. CONCLUSIONS: The STAI state sumscore is a biased indicator of anxiety in geriatric inpatients owing to confounding by well-being. The most important cause for the observed high score on the STAI state instrument in geriatric patients relates to a reduced well-being.

High prevalence of anxiety symptoms in hospitalized geriatric patients.

OBJECTIVE: To examine the prevalence of anxiety symptoms in hospitalized geriatric patients. DESIGN: Controlled cross-sectional study. SUBJECTS: Ninety-eight geriatric in-patients and 68 healthy home-dwelling controls of similar age recruited from senior citizen centres. OUTCOME MEASURE: Anxiety measured as a current emotional state by Spielberger's State-Trait Anxiety Inventory (STAI). RESULTS: The geriatric patients scored significantly higher than the controls. Applying Spielberger's recommended cut-off of 39/40 on the STAI sumscore, 41% of the female and 47% of the male geriatric patients might be suspected of suffering from significant anxiety symptoms. Patients with chronic obstructive pulmonary disease tended to score higher; otherwise no relationship was found between the STAI sumscore and type of chronic somatic disease, nor between the STAI sumscore and number of drugs in regular use. CONCLUSIONS: STAI proved feasible for use in the elderly. The scoring on the STAI is high in geriatric in-patients. Further studies are needed to clarify to what extent this relates to a high prevalence of anxiety disorders.

Electronic nose and artificial neural network.

Gas sensor array technology combined with multivariate data processing methods as artificial neural network has been demonstrated to have a promising potential for rapid nondestructive analysis of odour and flavour in foods. It may be applicable in quality control of raw material, food processing or products. This technique cannot completely replace reference methods like the use of sensory panels as the technique requires a frequent calibration against some valid reference method. As with all new techniques there remain some basic problems to be solved concerning sample handling and instrumental performance. The emerging research activity in the development of chemical sensors including hardware and software combined with applied research makes it realistic to expect applications with this technique implemented on-line in the food industry in near future. In particular, promising applications on meat seem to be within the field of spoilage, off-flavour, sensory analysis and fermentation processes.

Identification of animal species in ground meat mixtures by multivariate analysis of isoelectric focusing protein profiles.

The present work investigates the possibility of constructing a multivariate calibration model to predict the composition of ground meat with respect to animal species, based on intensity profiles from isoelectric focusing of water-soluble proteins in mixtures of ground meat. Samples containing various amounts of beef, pork and turkey meat were analyzed by isoelectric focusing in immobilized pH-gradients. The gels were photographed and the images transferred to a digital format. The digital images were processed in order to reduce background and optimize signal strength. Resulting gel profiles were analyzed by multivariate regression allowing the determination of sample composition with prediction errors close to 10%.