The stratified Petersen estimator with a known number of unread tags.

The Petersen estimator estimator of abundance can be biased when the assumption of homogeneous capture probability or homogeneous recapture probability is violated. Often this heterogeneity is related to the time or place of capture or recapture, and if these can be stratified, the stratified Petersen estimator reduces the bias caused by this heterogeneity. In some experiments, not all the recovered tagged animals can be examined, and only a subsample has its stratum of release and recovery determined. We develop methods for this modified experiment and apply them to estimate the number of salmon returning to spawn in a river in British Columbia, Canada.

Identification of a rosette-enriched chromatin fraction from mouse fibroblast nuclei.

We have characterized two components of DNA isolated from mouse L-M cell nuclei. These components, designated as HMW (high molecular weight) and VHMW (very high molecular weight) DNA, were characterized by rate zonal sedimentation, agarose gel electrophoresis, and for protein content. Our electron micrographs revealed that HMW-DNA contained mainly linear molecules with few single rosette structures, while the VHMW-DNA was enriched in rosettes, many of which were significantly larger and linked together in multimeric structural forms. The VHMW-DNA component was also enriched for residual protein, which we believe represents the core of the rosette. The characteristics of this residual protein are consistent with reported findings of the most tightly bound proteins. The rosette conformation does not appear to be an artifact of microscopy or of an aggregate nature for several reasons: (i) rosettes are preferentially found in the VHMW-DNA component; (ii) further manipulation or purification of the DNA disrupts the rosette structure and produces linear fragments; (iii) the amount of proteinaceous material at the core of the rosette is diminished when the DNA is further purified; and (iv) treatment of intact nuclei with a novel bisamine reagent putatively crosslinks DNA in vivo and minimizes the disruption of rosettes by shear. We believe this separation of chromatin is critical to establish the architectural forms of euchromatin and heterochromatin of interphase DNA in the eucaryotic system. Once established, fractionated chromatin can be used to identify specifically expressed or repressed genes with linear form DNA and rosette form DNA. We discuss rosettes as derivatives of chromosomal domains that retain structural features because of residual peptide elements.

Nursing care of oncology patients receiving chemotherapy.

As part of a research effort directed at identifying specific nursing activities related to the subsequent health status of the patient, this study explored relationships between selected nursing activities and patient outcomes for the oncology patient who was receiving chemotherapy. The study was correlational in design and descriptive in nature. Included in the study were 57 subjects from oncology and/or medical units in public and private nonprofit general hospitals. Human subjects' clearance was obtained for the study in each participating hospital. Data were collected primarily by means of patient and nurse responses to self-administered questionnaires. In the initial phase of data analysis, zero-order correlations were obtained for each pair of nursing activity and patient outcome variables. In addition, to identify relative contributions of different nursing activities to the health status of patients, regression analyses were performed in selected situations. The content and the quality of the explanation of the treatment and care regime were observed to be correlated positively with the patient's self-esteem. The quality of the explanation was observed to be positively related to the patient's knowledge base. Involving the patient in his care plan and giving him control over the activities of the day were positively correlated with importance of having things explained to him.