Domestication of olive fly through a multi-regional host shift to cultivated olives: comparative dating using complete mitochondrial genomes.

The evolutionary history of the olive fly, Bactrocera oleae, was reconstructed in a phylogenetic and coalescent framework using full mitochondrial genome data from 21 individuals covering the entire worldwide distribution of the species. Special attention was given to reconstructing the timing of the processes under study. The early subdivision of the olive fly reflects the Quaternary differentiation between Olea europea subsp. europea in the Mediterranean area and the two lineages of Olea europea subsp. cuspidata in Africa and Asia, pointing to an early and close association between the olive fly and its host. The geographic structure and timing of olive fly differentiation in the Mediterranean indicates a clear connection with the post-glacial recolonization of wild olives in the area, and is irreconcilable with the early historical process of domestication and spread of the cultivated olive from its Levantine origin. Therefore, we suggest an early co-history of the olive fly with its wild host during the Quaternary and post-glacial periods and a multi-regional shift of olive flies to cultivated olives as these cultivars gradually replaced wild olives in historical times.

The mitochondrial genomes of Campodea fragilis and Campodea lubbocki (Hexapoda: Diplura): High genetic divergence in a morphologically uniform taxon.

Complete mitochondrial genome sequences are presented from two dipluran hexapods (i.e., a group of "primarily wingless insects") of the genus Campodea and compared to those of other arthropods. Their gene order is the same as in most other hexapods and crustaceans. Structural changes have occurred in tRNA-C, tRNA-R, tRNA-S1 and tRNA-S2 as well as in both ribosomal RNAs. These mtDNAs have striking biases in nucleotide and amino acid composition. Although the two Campodea species are morphologically highly similar, their genetic divergence is larger than expected, suggesting a long evolutionary history, perhaps under stable ecological conditions.

Suicide: a literature review and its implications for nursing practice in Taiwan.

In recent years the suicide rates have been increasing gradually in many countries. In order to reduce the number of suicides, further research on suicide and the nursing care of suicidal people is required to enhance and advance the quality of suicide nursing care provided. Statistical evidence shows that the most common method of completing suicide in many countries is hanging. Other evidence demonstrates that some suicides could be prevented if all patients were assessed for suicide risk and if psychiatric nurses provided effective nursing care, which centres on therapeutic communication skills. This paper explores the literature on suicide and on the nursing care of people who are suicidal, and also on the importance of integrating theory with practice.

Nursing people who are suicidal on psychiatric wards in Taiwan: action/interaction strategies.

Suicide is a major mental health problem in Taiwan. Estimations revealed that approximately 41% of people who committed suicide had a previous history of psychiatric inpatient care. To date, a suicide nursing care theory has not been developed. Consequently, the aim of this study was to formulate a suicide nursing care theory with the aim of enhancing and advancing the nursing care provided to people who attempt suicide or have suicidal thoughts. A qualitative approach using grounded theory was adopted. A total of 15 peoples who had either suicidal ideas or had attempted suicide and 15 psychiatric nurses were interviewed and observed. Data were analysed using open, axial and selective coding and the NUD*IST software program. A substantive theory of suicide nursing care was developed from the emergent findings. Four categories surfaced in the nursing care theory relating to the nurses' 'action/interaction strategies'. They were: the holistic assessment of people who are suicidal; providing protection; providing basic care; and providing advanced care. The findings from this study could be used to influence and advance nurse education and training, clinical practice, management and further research.

Genes without frontiers?

For bacteria, the primary genetic barrier against the genetic exchange of DNA that is not self-transmissible is dissimilarity in the bacterial DNA sequences concerned. Genetic exchange by homologous recombination is frequent among close bacterial relatives and recent experiments have shown that it can enable the uptake of closely linked nonhomologous foreign DNA. Artificial vectors are mosaics of mobile DNA elements from free-living bacterial isolates and so bear a residual similarity to their ubiquitous natural progenitors. This homology is tightly linked to the multitude of different DNA sequences that are inserted into synthetic vectors. Can homology between vector and bacterial DNA enable the uptake of these foreign DNA inserts? In this review we investigate pUC18 as an example of an artificial vector and consider whether its homology to broad host-range antibiotic resistance transposons and plasmid origins of replication could enable the uptake of insert DNA in the light of studies of homology-facilitated foreign DNA uptake. We also discuss the disposal of recombinant DNA, its persistence in the environment and whether homologies to pUC18 may exist in naturally competent bacteria. Most DNA that is inserted into the cloning site of artificial vectors would be of little use to a bacterium, but perhaps not all.

The health behaviours of Chinese people with chronic illness.

This study was undertaken to elucidate the type and range of health-promoting behaviours that Chinese people with chronic illness perform to enhance their health. Eight people with a diagnosed chronic illness were interviewed using a semi-structured interview schedule. From the perspectives of these subjects, health behaviour comprises three dimensions: physical, psychosocial and spiritual. The results of this study clarify health behaviours amongst Chinese people with a chronic illness and illustrate the important influence that culture has upon such activity. Additionally, exploring the health behaviours of these Chinese people can be used to inform and enable nurses to adjust their practices to relate more appropriately to patients' perspectives.

The complete mitochondrial genome of the articulate brachiopod Terebratalia transversa.

We sequenced the complete mitochondrial DNA (mtDNA) of the articulate brachiopod Terebratalia transversa. The circular genome is 14,291 bp in size, relatively small compared with other published metazoan mtDNAs. The 37 genes commonly found in animal mtDNA are present; the size decrease is due to the truncation of several tRNA, rRNA, and protein genes, to some nucleotide overlaps, and to a paucity of noncoding nucleotides. Although the gene arrangement differs radically from those reported for other metazoans, some gene junctions are shared with two other articulate brachiopods, Laqueus rubellus and Terebratulina retusa. All genes in the T. transversa mtDNA, unlike those in most metazoan mtDNAs reported, are encoded by the same strand. The A+T content (59.1%) is low for a metazoan mtDNA, and there is a high propensity for homopolymer runs and a strong base-compositional strand bias. The coding strand is quite G+T-rich, a skew that is shared by the confamilial (laqueid) species L. rubellus but is the opposite of that found in T. retusa, a cancellothyridid. These compositional skews are strongly reflected in the codon usage patterns and the amino acid compositions of the mitochondrial proteins, with markedly different usages being observed between T. retusa and the two laqueids. This observation, plus the similarity of the laqueid noncoding regions to the reverse complement of the noncoding region of the cancellothyridid, suggests that an inversion that resulted in a reversal in the direction of first-strand replication has occurred in one of the two lineages. In addition to the presence of one noncoding region in T. transversa that is comparable with those in the other brachiopod mtDNAs, there are two others with the potential to form secondary structures; one or both of these may be involved in the process of transcript cleavage.

Complete sequence of the mitochondrial genome of the tapeworm Hymenolepis diminuta: gene arrangements indicate that Platyhelminths are Eutrochozoans.

Using "long-PCR," we amplified in overlapping fragments the complete mitochondrial genome of the tapeworm Hymenolepis diminuta (Platyhelminthes: Cestoda) and determined its 13,900-nt sequence. The gene content is the same as that typically found for animal mitochondrial DNA (mtDNA) except that atp8 appears to be lacking, a condition found previously for several other animals. Despite the small size of this mtDNA, there are two large noncoding regions, one of which contains 13 repeats of a 31-nt sequence and a potential stem-loop structure of 25 bp with an 11-member loop. Large potential secondary structures were identified also for the noncoding regions of two other cestode mtDNAS: Comparison of the mitochondrial gene arrangement of H. diminuta with those previously published supports a phylogenetic position of flatworms as members of the Eutrochozoa, rather than placing them basal to either a clade of protostomes or a clade of coelomates.

Exploring caring using narrative methodology: an analysis of the approach.

The investigation of caring in nursing practice and the need to explicate what it is nurses do when they care present a challenge for nurse researchers. This is due largely to the complex and nebulous nature of caring as a concept and the contextual elements that influence its perceived meaning. Consequently, the use of qualitative methods in the exploration of caring is the method of choice, with researchers employing a variety of such approaches. In particular, the use of stories as a primary way of making sense of an experience has gained attention in the literature and the narrative method is being seen increasingly as a valid means of tapping into the patient experience. However, the use of narratives is complex with a diversity of approaches often being presented. This paper discusses the use of narratives in the exploration of caring, focusing specifically on an approach developed by Donald Polkinghorne. Issues associated with the collection and analysis of narrative data using this approach are examined.

The evolving concept of health in nursing research: 1988-1998.

This article concerns the evolution of the concept of health, as reported in selected nursing journals, over the last 10 years. It builds on an analysis reported by Reynolds [Reynolds CL. The measurement of health in nursing research. Adv Nurs Sci 1988;10(4):23-31.] who initially investigated the concept of health and the means by which it was measured during the period 1977-1987. Using the same journals as Reynolds, the methodology of systematic review is used to analyse the way in which health is defined, the frequency with which it is investigated and the means by which it is measured, and these data are compared with Reynolds findings. The results indicate that; three times as many studies have been conducted in the last 10 years, a more holistic concept of health has emerged, and the instruments used are becoming more sophisticated. These findings are discussed and the implications for patient education and health care professionals considered.

Development and definition of the role of the operating department nurse: a review.

In the current cost-conscious National Health Service (NHS), the role of the nurse during anaesthesia and surgery is one that has interested health service managers keen to know what happens behind the closed doors of the operating department. It is clear that if nurses working within this specialized setting are to secure a future in providing care for surgical patients, then it is important to clarify and articulate exactly what it is that their role involves. The aim of this paper is to examine the role of the operating department nurse. First, it will illustrate how the role of the nurse has evolved alongside medical and technical advances in surgery, particularly in the last century. Second, it will highlight that while definition of the role has received attention in the North American literature, references in the British literature as to what it is that operating department nurses do, are scant. Finally, it will address the evolving role of the contemporary perioperative nurse highlighting the changes and challenges that nurses who work within this setting are currently facing. It is suggested here that nurses need to engage in role definition in order to be clear about their direction for the future, particularly within the fast changing, technologically driven environment of the operating department.

Fatigue in persons with renal failure who require maintenance haemodialysis.

Fatigue is a highly prevalent symptom experienced by persons who live with chronic illness, including those with renal failure who require maintenance haemodialysis. Fatigue, however, is a non-specific and invisible symptom and is a phenomenon that is poorly understood by health care professionals. This study examined the symptom of fatigue as experienced by a group of 39 adult haemodialysis patients. The theory of unpleasant symptoms formed the conceptual framework for the study. A descriptive correlational design was utilized to examine fatigue from an inductive approach, considering relevant physiological, psychological and situational variables based on a review of the literature. Data were collected using a structured self-report questionnaire and biochemical data from retrospective monthly blood tests. The results of the study indicated that high levels of fatigue are experienced, with correspondingly low levels of vitality, in all the areas measured - general fatigue, physical fatigue, reduced motivation, reduced activity and mental fatigue, by adult haemodialysis patients. Individual variation was noted in the dimensions of fatigue predominantly expressed. Fatigue was significantly associated with the presence of symptoms such as sleep problems, poor physical health status and depression. No associations between fatigue and the biochemical and situational variables measured were noted. Further examination of the data revealed complex relationships between the physiological and psychological factors examined. Depression was significantly associated with physical health status, sleep problems, symptoms and anxiety. Correlations were also noted between symptoms and poor physical functioning, sleep problems and depression. Based on the results, a revised version of the theory of unpleasant symptoms relating to fatigue is presented.

A novel type of RNA editing occurs in the mitochondrial tRNAs of the centipede Lithobius forficatus.

We determined the complete mtDNA sequence of the centipede Lithobius forficatus and found that only one of the 22 inferred tRNA genes encodes a fully paired aminoacyl acceptor stem. The other 21 genes encode tRNAs with up to five mismatches in these stems, and some of these overlap extensively with the downstream genes. Because a well-paired acceptor stem is required for proper tRNA functioning, RNA editing in the products of these genes was suspected. We investigated this hypothesis by studying cDNA sequences from eight tRNAs and found the editing of up to 5 nt at their 3' ends. This editing appears to occur by a novel mechanism with the 5' end of the acceptor stem being used as a template for the de novo synthesis of the 3' end, presumably by an RNA-dependent RNA polymerase. In addition, unusual secondary structures for several tRNAs were found, including those lacking a TPsiC (T) or a dihydrouridine (D) arm, and having an unusual number of base pairs in the acceptor or anticodon stems.

A comparison of an international experience for nursing students in developed and developing countries.

Theoretical perspectives and approaches to transcultural nursing have been developed and there are different options for teaching transcultural care. The opportunity for nursing students to gain healthcare experience in another country is one option. This article reports a study undertaken in Northern Ireland to evaluate outcomes of a 3-month international experience for undergraduate nursing students (n=74) and to assess differences between the experiences in developed and developing countries. Data were collected by questionnaire. The findings indicate a high impact on students' international perspective and career development. Students' understanding of cultural and political issues within Northern Ireland was enhanced.

The complete mitochondrial DNA sequence of the horseshoe crab Limulus polyphemus.

We determined the complete 14,985-nt sequence of the mitochondrial DNA of the horseshoe crab Limulus polyphemus (Arthropoda: Xiphosura). This mtDNA encodes the 13 protein, 2 rRNA, and 22 tRNA genes typical for metazoans. The arrangement of these genes and about half of the sequence was reported previously; however, the sequence contained a large number of errors, which are corrected here. The two strands of Limulus mtDNA have significantly different nucleotide compositions. The strand encoding most mitochondrial proteins has 1. 25 times as many A's as T's and 2.33 times as many C's as G's. This nucleotide bias correlates with the biases in amino acid content and synonymous codon usage in proteins encoded by different strands and with the number of non-Watson-Crick base pairs in the stem regions of encoded tRNAs. The sizes of most mitochondrial protein genes in Limulus are either identical to or slightly smaller than those of their Drosophila counterparts. The usage of the initiation and termination codons in these genes seems to follow patterns that are conserved among most arthropod and some other metazoan mitochondrial genomes. The noncoding region of Limulus mtDNA contains a potential stem-loop structure, and we found a similar structure in the noncoding region of the published mtDNA of the prostriate tick Ixodes hexagonus. A simulation study was designed to evaluate the significance of these secondary structures; it revealed that they are statistically significant. No significant, comparable structure can be identified for the metastriate ticks Rhipicephalus sanguineus and Boophilus microplus. The latter two animals also share a mitochondrial gene rearrangement and an unusual structure of mt-tRNA(C) that is exactly the same association of changes as previously reported for a group of lizards. This suggests that the changes observed are not independent and that the stem-loop structure found in the noncoding regions of Limulus and Ixodes mtDNA may play the same role as that between trnN and trnC in vertebrates, i.e., the role of lagging strand origin of replication.

Mitochondrial genomes of Galathealinum, Helobdella, and Platynereis: sequence and gene arrangement comparisons indicate that Pogonophora is not a phylum and Annelida and Arthropoda are not sister taxa.

We report a contiguous region of more than half (> 7,500 nt) of the mitochondrial genomes for Platynereis dumerii (Annelida: Polychaeta), Helobdella robusta (Annelida: Hirudinida), and Galathealinum brachiosum (Pogonophora: Perviata). The relative arrangements of all 22 genes identified for Helobdella and Galathealinum are identical to one another and to their arrangements in the mtDNA of the previously studied oligochaete annelid Lumbricus. In contrast, Platynereis differs from these taxa in the positions of several tRNA genes and in having two additional tRNA genes (trnC and trnM) and a large noncoding sequence in this region. Comparisons of relative gene arrangements and of the nucleotide and inferred amino acid sequences among these and other published taxa provide strong support for an annelid-mollusk clade that excludes arthropods, and for the inclusion of pogonophorans within Annelida, rather than giving them separate phylum status. Gene arrangement comparisons include the first use of a recently described method on previously unpublished data. Although a variety of alternative initiation codons are typically used by mitochondrial protein-encoding genes, ATG appears to be the initiator for all but one reported here. The large noncoding region (1,091 nt) identified in Platynereis has no significant sequence similarity to the noncoding region of Lumbricus, although each contains runs of TA dinucleotides and of homopolymers, which could potentially serve as signaling elements. There is strong bias for synonymous codon usage in Helobdella and especially in Galathealinum. In this latter taxon, 5 codons are completely unused, 13 are used three or fewer times, and G appears at third codon positions in only 26 of the 2,236 codons. Nucleotide composition bias appears to influence amino acid composition of the proteins.

Caring: theoretical perspectives of relevance to nursing.

Caring as a central concept within nursing has led to the development of several caring theories, the most well known being Madeleine Leininger's Theory of Culture Care and Jean Watson's Theory of Human Caring, both of which were formulated in the 1970s. This paper explores a total of four caring theories: the two established theories presented by Leininger and Watson, Simone Roach's theory developed in the 1980s, and a recent caring theory developed by Boykin & Schoenhofer. A comparison of these theories is presented drawing on a number of criteria, namely: origin of theory, scope of theory, definition of caring, description of nursing, key concepts of the theory, and goal/outcome. Additionally, simplicity as a central component of internal structure is examined in relation to each. Based on this analysis, similarities and differences are highlighted, concluding with a discussion of the utility of the caring theories within nursing practice.