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Biomedical subjects

L Bergen

Publications and source records attributed to L Bergen.

11 recordsLinked to original sources
PubMed2002

Early warning-system for operation-failures in biological stages of WWTPs by on-line image analysis.

By the observation and evaluation of the microscopic picture of activated sludge samples it is possible to introduce another biological parameter additional to conventional physico-chemical parameters for the control of biological stages of waste water treatment plants. Considering the fact that parameters like floc size and floc size distribution, structure of the flocs (compact/open), shape of the flocs (round/irregular) allow perceptions of the adjusted operation conditions of the biological stages, evidence for changing operation conditions or threatening operation disturbances can be recognised. This recognition takes place at a very early phase, because the morphology of activated sludge flocs reacts very fast to changing conditions. An automatic image analysis of activated sludge floc pictures would enable the introduction of a new sum parameter to enhance operation control of aeration tanks. By a statistical evaluation of the processed sludge images several parameters can be used to describe the alteration of activated sludge flocs characteristics. With these biological parameters it is possible to detect altered operation conditions or threatening or existing operation problems at an early phase. Thus it is possible to plan suitable countermeasures. Furthermore, the microscopic picture is the only parameter, that gives important information about the structure of the activated sludge flocs and the biozenosis. In comparison with the mainly used physico-chemical parameters, that just give information about the inlet and outlet of the wastewater treatment plants, the microscopic picture is the only parameter that gives information about the biology of the wastewater treatment process. By means of this biological parameter an improved control and regulation of the biological stages of wastewater treatment plants can be obtained.

Automation↗
PubMed1996

Staphylococcus aureus carriage and infections among patients in four haemo- and peritoneal-dialysis centres in Denmark. The Danish Study Group of Peritonitis in Dialysis (DASPID).

A three-month prospective surveillance study was undertaken in four dialysis centres to establish the prevalence of Staphylococcus aureus carriage in a Danish population of patients on haemodialysis (HD) or on continuous ambulatory peritoneal dialysis (CAPD). General data such as sex, age, diagnosis, number of months in dialysis, hospital and ward were registered on a precoded form. Standardized nose and four skin swabs (axillae, groins, perineum) were performed on the first day of the survey. After one and two months, nose swabs were collected. Infections were registered and cultures were sent for phage-typing together with the S. aureus strains isolated from the swabs; 59.5% of HD patients and 51.2% of CAPD patients carried S. aureus. Permanent carriage was most frequent (P < 0.00009), primarily in the nose (44.0 and 34.9%, respectively in HD and CAPD). Skin carriage alone was rare (2.4 and 4.7%). Approximately one third (36.6 and 40.7%) of infections were caused by S. aureus. Although diabetics were not significantly more frequent carriers (60.5%) than non-diabetics (55.0%), the incidence of infection was much higher (26.3% vs. 10.3%, P = 0.004). In CAPD, peritonitis and tunnel/exit-site infections predominated (81.4%), often caused by S. aureus (34.8%). More than two thirds of the infections in HD patients were related to intravascular catheterization. The most serious infection was septicaemia, in all cases due to S. aureus. S aureus infections occurred significantly more frequently among carriers (P = 0.005), and more than half the patients were infected by the same or possibly the same strain as they carried in the nose or on skin. Different regimens for the elimination of S. aureus carriage in dialysis patients are discussed. A policy for risk assessment of patients should be developed, and the elimination of S. aureus carriage before dialysis should be encouraged. Controlled trials comparing the cost-effectiveness of recommended regimens to eliminate carriage in HD/CAPD patients are needed. Nose swabs are reliable indicators of carriage in dialysis patients.

Carrier State↗
PubMed1990

Treatment decisions for the elderly.

Patients must be given the opportunity to make medical treatment choices. Based on legal and clinical precedents, guidelines must be established for determining the choice-making competency of persons unable to make their own decisions.

Aged↗
PubMedDate not supplied

The reification of normalcy.

Many researchers who investigate the putative effects of violent television on normal children claim there is a lifetime sociopathic effect on many of the children who watch. There may be. But there is a prevailing assumption that because television can produce sociopathic effects in a laboratory, that it does outside the laboratory. In addition, uncritical assumptions of psychological normalcy among most viewers are so prevalent among researchers in this field that any pathological lifetime effect may be exaggerated. The incidence of psychopathology, especially among nonrandom subject samples obtained from public schools, may be higher than investigators suspect, which could lead to overestimates of pernicious effects by television on children. Because pathological children are more vulnerable to commercial television's putative sociopathic effects than are normal children, they may bias study results toward sociopathic attitudes and behaviors, thus misleading researchers into believing that television has a greater sociopathic effect on normal populations than it actually has. Those psychopathologies are reviewed and prospective remedies are suggested for helping those children cope with the possible sociopathic effects of violently oriented television.

Adaptation, Psychological↗