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1.
Results of a long-term study of the taxonomy, distribution and abundance of the hermatypic corals of the Ryukyu Is. and mainland Japan indicate that the present high diversity is threatened by a quantitative and qualitative decrease in available habitat caused by Acanthaster planci predation and human-induced environmental deterioration. Ninety-eight sites were studied, allowing detailed comparison between the three main groups of the Ryukyu Is. (Yaeyama, Okinawa and Amami Groups) and seven principal coral regions of mainland Japan (Tanegashima, Amakusa Is., the Tosashimizu and Kushimoto regions, and the Shirahama, Izu and Tateyama Peninsulas). Within this area, 400 species have been recorded and 9 additional species are recorded from the literature, from additional localities, or with doubt, from the Ryukyu Is. In non-mutually exclusive distribution and abundance categories for the Ryukyu Is. and mainland Japan: 129 species are common in at least some Japanese localities; 24 are widely dispersed within the Indo-Pacific, but occur in small, perhaps disjunct populations in Japan; 149 are uncommon throughout their Indo-west Pacific distribution ranges including Japan; 38 are restricted to the Yaeyama Group where all but three are uncommon or rare; 69 purely reefal (Ryukyu Is.) species are rare; 17 are rare in the Ryukyu Is. but are relatively common in mainaland locations; and 8 species appear to be endemic to mainland Japan and adjacent Asian countries. Some 37% of all Japanese hermatypic corals are uncommon throughout their range in Japan and are at some risk of regional extinction, 29% of others are rare and at substantial risk as they occur only in very limited areas of high diversity or in species-specific refuges. These sites are dientified. Of the 8 endemic species, 5 are primarily restricted to species-specific refuges. These data indicate an unstable situation. At least one third of all Japanese hermatypic species will eventually be at risk if the present causes of diversity decrease are not remedied.  相似文献   
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Recently, interest in the enzyme nucleoside diphosphate kinase (EC2.7.4.6) has increased as a result of its possible involvement in cell proliferation and development. Since NDP kinase is one of the major sources of GTP in cells, it has been suggested that the effects of an altered NDP kinase activity on cellular processes might be the result of altered transmembrane signal transduction via guanine nucleotide-binding proteins (G-proteins). In the cellular slime mould Dictyostelium discoideum, extracellular cAMP induces an increase of phospholipase C activity via a surface cAMP receptor and G-proteins. In this paper it is demonstrated that part of the cellular NDP kinase is associated with the membrane and stimulated by cell surface cAMP receptors. The GTP produced by the action of NDP kinase is capable of activating G-proteins as monitored by altered G-protein-receptor interaction and the activation of the effector enzyme phospholipase C. Furthermore, specific monoclonal antibodies inhibit the effect of NDP kinase on G-protein activation. These results suggest that receptor-stimulated NDP kinase contributes to the mediation of hormone action by producing GTP for the activation of GTP-binding proteins.  相似文献   
4.
Gunzburg J  Veron M 《The EMBO journal》1982,1(9):1063-1068
We demonstrate the occurrence of a cAMP-dependent protein kinase in Dictyostelium discoideum cells at the terminal stage of differentiation. A cAMP-binding component was purified to homogeneity by affinity chromatography. This subunit inhibits the activity of purified catalytic subunit from beef heart protein kinase; the inhibition is reversed upon addition of cAMP. The protein is highly specific for cAMP and has a dissociation constant of 4 nM. The isolated regulatory subunit is a monomer of 39 K, with a sedimentation coefficient of 3.5S and a frictional coefficient of 1.24. The differences between this regulatory subunit and regulatory subunits of protein kinases from other sources are discussed.  相似文献   
5.
Natriuretic peptides of various forms are present in animals and plants, and display structural similarities to cyclic antibacterial peptides. Pretreatment of Pseudomonas aeruginosa PAO1 with brain natriuretic peptide (BNP) or C-type natriuretic peptide (CNP) increases bacterium-induced glial cell necrosis. In eukaryotes, natriuretic peptides act through receptors coupled to cyclases. We observed that stable analogs of cAMP (dibutyryl cAMP) and cGMP (8-bromo-cGMP) mimicked the effect of brain natriuretic peptide and CNP on bacteria. Further evidence for the involvement of bacterial cyclases in the regulation of P. aeruginosa PAO1 cytotoxicity by natriuretic peptides is provided by the observed doubling of intrabacterial cAMP concentration after exposure to CNP. Lipopolysaccharide (LPS) extracted from P. aeruginosa PAO1 treated with both dibutyryl cAMP and 8-bromo-cGMP induces higher levels of necrosis than LPS extracted from untreated bacteria. Capillary electrophoresis and MALDI-TOF MS analysis have shown that differences in LPS toxicity are due to specific differences in the structure of the macromolecule. Using a strain deleted in the vfr gene, we showed that the Vfr protein is essential for the effect of natriuretic peptides on P. aeruginosa PAO1 virulence. These data support the hypothesis that P. aeruginosa has a cyclic nucleotide-dependent natriuretic peptide sensor system that may affect virulence by activating the expression of Vfr and LPS biosynthesis.  相似文献   
6.
This study investigates the effects of emotion-oriented care on the behavior of elderly people with cognitive impairment and behavioral problems. This approach is mainly based on the validation approach, but uses also insights from other approaches like reminiscence and sensory stimulation. Sixteen homes for the aged with structured day care units were randomly allocated to an intervention or control group. 151 Residents with cognitive impairment and behavioral problems were included in the study. The eight intervention homes received a training program with regard to emotion-oriented care. In the eight control homes usual care was continued. Measurements were performed at baseline and after three, six and twelve months of follow-up (assessment by caregivers and relatives). The primary outcome measure was the change in behavior of the residents. The results of multilevel analyses (overall, subgroup and per protocol) showed no statistically significant, nor clinically relevant effects in favor of the intervention group on the behavioral outcome measures. A possible reason for this is that the intervention did not result in significant contrast between the study groups. There is insufficient scientific evidence yet to justify the implementation of emotion-oriented care in residential homes, for residents with moderate to severe cognitive impairment and behavioral problems, on a large scale. Additional studies are needed in which special attention should be given to the implementation process.  相似文献   
7.
This study was designed to investigate the effects of work schedules on the health of hospital workers at the Assistance Publique-H?pitaux de Paris (AP-HP). Out of 40 hospitals, 17 volunteered to participate in this study. The Standard Shiftwork Index and a questionnaire concerning physicians' work schedules were used. Ten thousand questionnaires were distributed anonymously to hospital workers between March and April 1999. Professional categories comprised head nurses, nurses, nursing auxiliaries, hospital agents, midwives and full time physicians. Departments included internal and geriatric medicine, general paediatrics, orthopaedic and general surgery, operating and emergency rooms, and anaesthesiology and intensive care units. 3250 questionnaires were returned. Demographics for the respondents were: 79.2% female, average age 38.1 +/- 9.1 years old. Eleven work schedules were identified. One fourth of the personnel had fixed morning work schedules. The highest level of job satisfaction was found in personnel working in paediatrics while dissatisfaction was strongest in the gerontology and, emergency room personnel. General Health Questionnaire (GHQ) scores were high for head nurses, operating room nurses and junior doctors as well as for personnel with rotating and flexible shifts. This study will be used to make recommendations concerning the reduction of working time for French hospital workers.  相似文献   
8.
Although recent molecular studies have clarified the phylogeny of mongooses, the systematics of the Southeast Asian species was incomplete as the collared mongoose Urva semitorquata and some debatable taxa (Hose's mongoose, Palawan mongoose) were missing in the analyses. We sequenced three mitochondrial (cytochrome b, ND2, control region) and one nuclear (beta‐fibrinogen intron 7) fragments of the Southeast Asian mongooses to clarify the systematic position of the different species and populations occurring in this region. Our results showed that the collared mongoose is closely related to the crab‐eating mongoose Urva urva, these two species forming a sister‐group to the short‐tailed mongoose Urva brachyura. Despite Sumatran collared mongooses having a peculiar orange phenotype, we showed that they exhibited very little genetic divergence to individuals from Borneo. In contrast, the populations of the short‐tailed mongoose from Borneo were strongly divergent to those from Peninsular Malaysia and Sumatra, and these might represent separate species. Within the crab‐eating mongoose, we observed little geographical genetic structure. Our study suggests that Hose's mongoose is not a valid species. The Palawan mongooses did not cluster with the other populations of the short‐tailed mongoose; they were closer to the collared mongoose and should be included in this species. © 2014 The Linnean Society of London  相似文献   
9.
Recipients of Darwin Medals from the International Society of Reef Studies are requested to write an overview of the work that led to their award. This account is a personal perspective of thirty-five years work on corals. The fields of taxonomy, biogeography, palaeontology, molecular biology, and evolution are presented in an historical context. Emphasis is given to the changing relevance of these fields to today’s world of information technology and the ever-increasing conservation needs.  相似文献   
10.
BACKGROUND: Gene delivery in dendritic cells (DC) has raised considerable interest to modulate DC functions and induce therapeutic immunity or tolerance in an antigen-specific fashion. Among immature DC, Langerhans cells (LC) are attractive candidates for antigen delivery using lentiviral vectors (LV). METHODS: LC derived from monocytes (Mo-LC), or derived from CD34+ cells (CD34-LC) in the presence of cytokine cocktail, were transduced with LV expressing enhanced green fluorescent protein (E-GFP) under the control of the ubiquitous phosphoglycerate kinase (PGK) promoter at a multiplicity of infection of 18, at days 0 to 3 for Mo-LC, or at days 0 to 12 for CD34-LC. We assessed gene transfer levels from the percentage of E-GFP+ cells in the final cultures, and examined the morphology, immunophenotype, state of differentiation and function of transduced LC. RESULTS: Day 0 transduction of monocytes or CD34+ progenitors before cytokine pre-activation and LC differentiation resulted in stable gene expression in 7.8% of Mo-LC and 24% of CD34-LC. Monocyte-derived DC (Mo-DC) differentiated in serum-free medium were also efficiently transduced up to 13.2%. Interestingly, Mo-LC cells committed towards LC phenotype were permissive for transduction up to day 3. Transduction levels of CD34-LC peaked at day 6 to 44% and decreased thereafter. LV transduction did not perturb viability, phenotype and function of E-GFP-expressing LC. CONCLUSIONS: LC generated ex vivo can serve as vaccine vehicles in humans through efficient transduction by LV. These LC will be helpful to assess in vitro the immunogenicity of gene therapy vectors, from the characterization of their phenotypic and functional maturation.  相似文献   
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