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31.
PETER TYRER ROGER MULDER MIKE CRAWFORD GILES NEWTON‐HOWES ERIK SIMONSEN DAVID NDETEI NESTOR KOLDOBSKY ANDREA FOSSATI JOSEPH MBATIA BARBARA BARRETT 《World psychiatry》2010,9(1):56-60
Personality disorder is now being accepted as an important condition in
mainstream psychiatry across the world. Although it often remains unrecognized
in ordinary practice, research studies have shown it is common, creates considerable
morbidity, is associated with high costs to services and to society, and interferes,
usually negatively, with progress in the treatment of other mental disorders.
We now have evidence that personality disorder, as currently classified, affects
around 6% of the world population, and the differences between countries show
no consistent variation. We are also getting increasing evidence that some
treatments, mainly psychological, are of value in this group of disorders.
What is now needed is a new classification that is of greater value to clinicians,
and the WPA Section on Personality Disorders is currently undertaking this
task. 相似文献
32.
THOMAS H. McGOVERN ORRI VÉSTEINSSON ADOLF FRIRIKSSON MIKE CHURCH IAN LAWSON IAN A. SIMPSON ARNI EINARSSON Y DUGMORE GORDON COOK SOPHIA PERDIKARIS KEVIN J. EDWARDS AMANDA M. THOMSON W. PAUL ADDERLEY ANTHONY NEWTON GAVIN LUCAS RAGNAR EDVARDSSON OSCAR ALDRED ELAINE DUNBAR 《American anthropologist》2007,109(1):27-51
Early settlement in the North Atlantic produced complex interactions of culture and nature. The sustained program of interdisciplinary collaboration is intended to focus on ninth- to 13th-century sites and landscapes in the highland interior lake basin of Mývatn in Iceland and to contribute a long-term perspective to larger issues of sustainable resource use, soil erosion, and the historical ecology of global change. 相似文献
33.
Atmospheric nitrogen deposition in world biodiversity hotspots: the need for a greater global perspective in assessing N deposition impacts 总被引:8,自引:0,他引:8
GARETH K. PHOENIX W. KEVIN HICKS† STEVE CINDERBY† JOHAN C. I. KUYLENSTIERNA† WILLIAM D. STOCK‡§ FRANK J. DENTENER¶ KEN E. GILLER AMY T. AUSTIN ROD D. B. LEFROY†† BEN S. GIMENO‡‡ MIKE R. ASHMORE§§ PHILIP INESON¶¶ 《Global Change Biology》2006,12(3):470-476
Increased atmospheric nitrogen (N) deposition is known to reduce plant diversity in natural and semi‐natural ecosystems, yet our understanding of these impacts comes almost entirely from studies in northern Europe and North America. Currently, we lack an understanding of the threat of N deposition to biodiversity at the global scale. In particular, rates of N deposition within the newly defined 34 world biodiversity hotspots, to which 50% of the world's floristic diversity is restricted, has not been quantified previously. Using output from global chemistry transport models, here we provide the first estimates of recent (mid‐1990s) and future (2050) rates and distributions of N deposition within biodiversity hotspots. Our analysis shows that the average deposition rate across these areas was 50% greater than the global terrestrial average in the mid‐1990s and could more than double by 2050, with 33 of 34 hotspots receiving greater N deposition in 2050 compared with 1990. By this time, 17 hotspots could have between 10% and 100% of their area receiving greater than 15 kg N ha?1 yr?1, a rate exceeding critical loads set for many sensitive European ecosystems. Average deposition in four hotspots is predicted to be greater than 20 kg N ha?1 yr?1. This elevated N deposition within areas of high plant diversity and endemism may exacerbate significantly the global threat of N deposition to world floristic diversity. Overall, we highlight the need for a greater global approach to assessing the impacts of N deposition. 相似文献
34.
Role of interaction zones between surface and ground waters in DOC transport and processing: considerations for river restoration 总被引:3,自引:0,他引:3
- 1 A study of dissolved organic carbon (DOC), nitrates and total dissolved phosphorus (TDP) concentrations, conductivity and bacterial numbers was undertaken in subsurface water of the Garonne River (France) under low-flow conditions. The velocity of subsurface flow through a 300-m gravel bar, during this study, was less than 43 m day?1. DOC, nitrates and TDP concentrations, conductivity and bacterial numbers fluctuated within the gravel bar with no discernible spatial pattern. Bacterial abundance was correlated with DOC concentration. Results were compared to a previous study of the Stillaguamish River (U.S.A.) (Vervier & Naiman, 1992).
- 2 These studies provide evidence that gravel bars are important in the processing of DOC by bacteria in the subsurface water. Bacterial activity is, in turn, determined by sources of DOC from upstream at high discharge, and by patchy local microhabitats at low discharge.
- 3 Restoration of rivers should incorporate, wherever possible, meanders with associated gravel bars and riffles. These will improve DOC-processing capacity, in addition to other benefits predicted by the Building Block Model (Petersen, Petersen & Lacoursière, 1992).
35.
Stream community structure in relation to spatial and temporal variation: a habitat templet study of two contrasting New Zealand streams 总被引:5,自引:1,他引:4
- 1 The physical characteristics of two contrasting streams, and habitat types within these streams, are described in terms of a two-dimensional physical habitat templet in which disturbance frequency and the availability of spatial refugia are the temporal and spatial axes.
- 2 It is predicted that habitats experiencing a high disturbance frequency and low refuge availability will be characterized by a low invertebrate species diversity, a low biomass of epilithic algae and particulate organic matter and a community made up of mobile, weedy species. Habitats having a low disturbance frequency and high refuge availability will be characterized by a diverse community containing sedentary and specialist species, with high algal and particulate organic matter levels.
- 3 A lower median substrate particle size and higher shear stress regime in Timber Creek were indicative of a higher disturbance frequency than in the Kyeburn. Substrate diversity was lower in Timber Creek than in the Kyeburn and indicated that the availability of refugia was lower in Timber Creek. In both streams, pools were found to have a higher disturbance frequency and lower availability of refugia than riffles.
- 4 Invertebrate species diversity, the biomass of epilithic algae and particulate organic matter and the representation of sedentary species, filter feeders and shredders were higher in the more temporally stable and spatially heterogeneous Kyeburn. The community of Timber Creek, frequently disturbed and having low refuge availability, had a high proportion of mobile and weedy species, with the highly mobile, generalist-feeding Deleatidium spp. (Ephemeroptera; Leptophlebiidae) being the most dominant organisms.
- 5 The predictions made about stream community structure and species characteristics in relation to disturbance frequency and the availability of spatial refugia are generally supported. Now a larger scale investigation is required to test the generality of the predictions. We conclude that the habitat templet approach offers a sound framework within which to pose questions in stream ecology.
36.
Changes in the plastid ultrastructure as revealed by thin-section electron-microscopy, chlorophyll a/b ratio, and the polypeptides of the thylakoid chlorophyll-protein complexes have been examined during the degreening of bananas (Musa AAA Group, Cavendish Subgroup) and plantains (Musa AAB Group, Plantain Subgroup) ripened at 20°C and 35°C. In bananas, where degreening is inhibited at temperatures above 24°C, ripening at the higher temperature results in a retention of thylakoid membranes, a relatively delayed breakdown in chlorophyll b, and a reduced dismantling of pigment-protein complexes. By contrast, in plantains, where degreening is complete within 4 days at both 20°C and 35°C, thylakoid membranes and their associated pigment-protein complexes are lost, and there is a rapid increase in chlorophyll a/b ratios at both ripening temperatures. It is suggested that the retention of thylakoid membranes is an important factor in the failure of Cavendish bananas to degreen when ripened at tropical temperatures, and that the degreening problem may be related to the comparatively high chlorophyll b content of the preclimacteric fruit. 相似文献
37.
D. PHILIP WHITFIELD ALAN H. FIELDING MIKE J. P. GREGORY A. G. GORDON DAVID R. A. McLEOD & PAUL F. HAWORTH 《Ibis》2007,149(1):26-36
The development of commercial forests presents potential threats to large raptors that rely on prey caught in open country. We examined the effect of afforestation of breeding habitat used by a population of Golden Eagles Aquila chrysaetos in Scotland where, over the last 50 years, extensive stands of exotic conifers have been planted. Using data for 31 years on territory occupancy and breeding success, together with spatiotemporally dynamic mapping of forest cover and predicted areas of territory‐use in a Geographical Information System, we examined relationships between forest cover and Eagle ecology at landscape and individual territory scales. Several territories were abandoned during the earliest phases of forest planting, but relatively few were apparently lost to later plantings. Territories with poorer breeding productivity appeared to be more vulnerable to abandonment than territories with better breeding productivity. At the landscape scale, temporal differences in breeding productivity were negatively related to the extent of forest cover, although productivity of individual territories showed no clear relationship with forest cover. Several territories with less than a 5% increase in forest cover experienced reduced productivity; however, territories least constrained by neighbouring pairs of Eagles showed an increase in productivity. Territories experiencing the greatest increases in forest cover showed a greater use of spatially separated nest‐sites by occupying pairs. Hence, pairs that were less constrained by neighbours appeared to compensate for loss of open habitat by shifting their territory‐use, whereas pairs that were more constrained could not compensate for open habitat loss and suffered reduced productivity (and, probably in some cases, abandoned the territory). We suggest that simple guidelines based on the extent and locations of habitat loss are inadequate when predicting effects on large territorial raptors such as Golden Eagles. Consideration should also be given to the ‘quality’ of a territory or occupying pair, as well as the extent to which territory‐use is constrained by neighbouring pairs or other ‘unsuitable habitat’ which may have been affected by previous episodes of open habitat loss. 相似文献
38.
Disease progress of non-specialised fungal pathogens in intraspecific mixed stands of cereal cultivars. II. Field experiments 总被引:5,自引:0,他引:5
Epidemic development of Septoria nodorum was examined in pure stands and mixtures of two spring wheat cultivars, Kolibri and Maris Butler. In mixtures, disease development was reduced almost to that of the more resistant pure stand (Maris Butler). Disease levels, however, were low and no significant differences in grain yield per head were demonstrated. Disease development was further investigated for the host-pathogen combinations winter wheat/S. nodorum and winter barley/Rhynchosporium secalis. With both combinations the mixed stands again reduced disease levels to almost that of the more resistant pure stands. In general, mixed stands were more effective against R. secalis, although, with S. nodorum, disease levels were low. The yield response in mixed stands differed for the host cultivars and was not significantly changed by the presence of disease. The complexity of analysing such situations and the implications of these findings for mixtures of cultivars differing in resistance to non-specialised pathogens are discussed. 相似文献
39.
A phylogenetic reconstruction of the Ichneumonoidea (Hymenoptera) based on the D2 variable region of 28S ribosomal RNA 总被引:7,自引:0,他引:7
ROBERT BELSHAW MIKE FITTON ELISABETH HERNIOU CARMEN GIMENO & DONALD L. J. QUICKE 《Systematic Entomology》1998,23(2):109-123
The D2 variable region of 28S rRNA was sequenced in a wide range of Ichneumonoidea to provide the first comprehensive phylogenetic reconstruction of this superfamily. The two constituent families (Braconidae and Ichneumonidae) were each found to contain a single well-supported clade dominated by the more plesiomorphic life history strategies (idiobiosis, ectoparasitism and attacking endoephytic hosts). In the Braconidae this clade corresponds to the morphologically-defined group called the cyclostomes. In the Ichneumonidae the clade unites for the first time the pimpliformes ( sensu Wahl) with most of the phygadeuontoid subfamilies and several small taxa including Adelognathus and Euceros . Relationships among the remaining, more biologically-derived, subfamilies were less well resolved, but included among the Braconidae a well-supported microgastroid clade and strong evidence for a sister group relationship between the Agathidinae and Sigalphinae. 相似文献
40.
MIKE BIRKHEAD 《Ibis》1985,127(4):467-475
Three complete Mallard Anas platyrhyncos clutches from a single site were analysed to determine intra-and inter-clutch variation within and among clutches in quality and composition. Variation between clutches was significantly greater than within clutches in all the examined criteria of egg composition, except for the percentage of water found in yolk. In addition the weight of the yolk was proportional to fresh egg weight. When log transformations were used, the slope of the regression was greater than unity, indicating the proportional contribution of yolk increased respectively with egg weight. A total of 26 eggs from four locations was analysed and no regional variation in egg composition was found but there was variation in egg quality (lipid and protein). The factors affecting the production of a 'good egg' and what in fact is a 'good egg' are discussed. In the Mallard, as in other Anseriformes, it appears that larger eggs may confer a survival advantage to the subsequent young. 相似文献