The human X chromosome has a unique biology that was shaped by its evolution as the sex chromosome shared by males and females. We have determined 99.3% of the euchromatic sequence of the X chromosome. Our analysis illustrates the autosomal origin of the mammalian sex chromosomes, the stepwise process that led to the progressive loss of recombination between X and Y, and the extent of subsequent degradation of the Y chromosome. LINE1 repeat elements cover one-third of the X chromosome, with a distribution that is consistent with their proposed role as way stations in the process of X-chromosome inactivation. We found 1,098 genes in the sequence, of which 99 encode proteins expressed in testis and in various tumour types. A disproportionately high number of mendelian diseases are documented for the X chromosome. Of this number, 168 have been explained by mutations in 113 X-linked genes, which in many cases were characterized with the aid of the DNA sequence.

The rhesus macaque (Macaca mulatta) is an abundant primate species that diverged from the ancestors of Homo sapiens about 25 million years ago. Because they are genetically and physiologically similar to humans, rhesus monkeys are the most widely used nonhuman primate in basic and applied biomedical research. We determined the genome sequence of an Indian-origin Macaca mulatta female and compared the data with chimpanzees and humans to reveal the structure of ancestral primate genomes and to identify evidence for positive selection and lineagespecific expansions and contractions of gene families. A comparison of sequences from individual animals was used to investigate their underlying genetic diversity. The complete description of the macaque genome blueprint enhances the utility of this animal model for biomedical research and improves our understanding of the basic biology of the species.

Comparative analysis of the sea urchin genome has broad implications for the primitive state of deuterostome host defense and the genetic underpinnings of immunity in vertebrates. The sea urchin has an unprecedented complexity of innate immune recognition receptors relative to other animal species yet characterized. These receptor genes include a vast repertoire of 222 Toll-like receptors, a superfamily of more than 200 NACHT domain-leucine-rich repeat proteins (similar to nucleotide-binding and oligomerization domain (NOD) and NALP proteins of vertebrates), and a large family of scavenger receptor cysteine-rich proteins. More typical numbers of genes encode other immune recognition factors. Homologs of important immune and hematopoietic regulators, many of which have previously been identified only from chordates, as well as genes that are critical in adaptive immunity of jawed vertebrates, also are present. The findings serve to underscore the dynamic utilization of receptors and the complexity of immune recognition that may be basal for deuterostomes and predicts features of the ancestral bilaterian form.

OBJECTIVES. The purpose of the study was to provide descriptive data and incidence data on adolescent work-related injuries and to determine whether such injuries are underreported to the Minnesota Department of Labor and Industry. METHODS. The study consisted of a 1-year survey of 534 adolescent work-related injuries reported to the Department of Labor and Industry and a cross-sectional survey of 3312 public high school students from throughout Minnesota. The high school survey used an abbreviated questionnaire with a subset of items from the Department of Labor and Industry survey. RESULTS. Ninety-six percent of the injuries were strains and sprains, cuts and lacerations, burns, bruises and contusions, and fractures. There were 11 hospitalizations; 4 were for burns that occurred during work in restaurants. Eighty workers (15%) reported permanent impairment as a result of their injuries. It was estimated that there were 2268 reportable injuries to working adolescents in Minnesota during the study year. CONCLUSIONS. The most common serious injuries were injuries to the lower back and burns. The demographic characteristics of adolescents whose injuries were reported to the Department of Labor and Industry were similar to those of injured adolescent workers identified through the high school survey. The results suggest that there is substantial underreporting of adolescent work injuries.

In its quest for knowledge, nursing has relied heavily on the positivist approach to scientific enquiry. Phenomenological enquiry identifies the essence of a phenomenon and accurately describes it through the lived experience. Through consistency in the use of the methodology, and avoidance of method slurring, academic rigour can be maintained. It is advocated that the phenomenological method is congruent with nursing ideals where humanistic knowledge is valued. Nurses and phenomenologists share skills in observation, interviewing, interaction and interpersonal relationships in the appreciation of the individual's perception of an experience. Through the development of professional practice, nurses thus gain the tools to assist them in phenomenological research. It is suggested that, given appropriate attention to rigour, phenomenological methodology could become the basic instrument in the reform of nursing research as it moves from the positivist to the humanist paradigm.

Background The Minnesota Sentinel Event Notification System for Occupational Risks (SENSOR) has collected data on the nature, incidence, and cause of work‐related amputation injuries that have taken place since 1992. Methods SENSOR defined an amputation as any finger amputation or the loss of any other body part; 832 workers were identified as having amputation injuries between 1994 and 1995 and 72% of these workers completed telephone interviews. Results The amputation injury rate for Minnesota workers was 39 per 100,000 workers, with agriculture and manufacturing having the highest rates. Sixty‐six percent of the injuries involved one finger; 14% involved two or more fingers. Persons working with machinery reported 73% of the injuries. Conclusions A closer examination of the incidence and causes for amputation injuries shows that these were not random events. Reliance on human reactions to prevent injury is inadequate; therefore, additional research needs to be conducted. Am. J. Ind. Med. 37:542–550, 2000. © 2000 Wiley‐Liss, Inc.

Focus groups provide important insights into intervention development in very small enterprises in general and auto collision shops in specific. Employers were conflicted about allowing employees a certain level of independence while also maintaining a safe workplace. From the employee perspective, owners frequently fail to provide adequate personal protective equipment and make improvements needed to ensure safe work. The unique managerial needs of very small enterprises must be accounted for if health and safety programs are to be implemented in these establishments.

Despite the dearth of rigorous empirical investigation, reflection and reflective practice have become buzz words in nursing and midwifery education Reflection and critical incident analysis may be tools which can facilitate the integration of theory and practice It is proposed that in the absence of explicit and thorough preparation of lecturers and students, together with very careful curriculum planning, these activities may be counter‐productive or even harmful In the absence of structure, reflection and associated critical incident analysis may lead to student disaffection or, worse, the potential for actual psychological disturbance Empirical studies on the use of identified models of reflection and critical incident analysis are urgently needed to assist nursing and midwifery lecturers and students to achieve predictable learning outcomes for this potentially valuable activity