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931.
F. NESLIHAN INAL-EIROGLU AYSEGUL OZERDEM DAVID MIKLOWITZ AYSEN BAYKARA AYNUR AKAY 《World psychiatry》2008,7(2):110-112
The study aimed to ascertain the prevalence of mood and disruptive behavior disorders and symptoms in 35 children of 29 adult outpatients with a DSM-IV diagnosis of bipolar I disorder, compared with 33 children of 29 healthy adults, matched with patients on age, socioeconomic status and education. The offspring of bipolar patients had a 9.48 fold higher risk of receiving a psychiatric diagnosis. While only two children of patients with bipolar disorder were diagnosed with a mood disorder, 30.9% displayed mild depressed mood, compared with 8.8% of the controls, a statistically significant difference. The bipolar offspring also scored significantly higher on the hyperactivity and conduct problems subscales as well as the ADHD index of the Conners’ Teacher Rating Scale. The disruptive behavior and mood symptoms observed in early life in the offspring of bipolar patients may indicate the need for early psychosocial intervention. 相似文献
932.
J. MARK DANGERFIELD ANTHONY J. PIK DAVID BRITTON ANDREW HOLMES MICHAEL GILLINGS IAN OLIVER DAVID BRISCOE ANDREW J. BEATTIE 《Austral ecology》2003,28(3):227-236
Abstract Most ecologists are comfortable with the notion of habitats as recognizable entities and also with situations where the junction between two adjacent habitats forms a discrete edge. Such edges form naturally because of sharp changes in important edaphic, geomorphological, climatic or chemical properties to which plants, in particular, respond. Less clear is the effect of such edges on assemblages of mobile organisms, especially invertebrates that operate at relatively small spatial scales. The objective of the present study was to sample invertebrate composition across a natural edge between a well‐developed riparian habitat on fluvial sands and a saltbush habitat developed on a stony gibber plain in a semi‐arid region of New South Wales, Australia. A total of 150 pitfall traps on five 1‐km‐long transects that straddled the edge produced more than 13 000 adult specimens from 21 ordinal invertebrate taxa. A total of 10 446 beetle, ant, wasp, fly and springtail specimens were further sorted into 426 morphospecies. Comparisons and estimates of trends in abundance and richness were made, along with computation of multivariate dissimilarity and permutation statistics, to determine if the land system edge was coincident with changes in invertebrate abundance and composition. These analyses were unable to detect disjunctions in diversity coincident with the edge. The data suggest that many taxa are either present consistently in both habitats or are mostly found in one habitat but ‘leak’ several hundred metres across into the other. Few taxa were unique to either habitat. The result is that assemblage composition for invertebrates changes gradually over distances of up to 400 m either side of the edge and that the distance to a recognizable change in composition is taxon dependent. Even sharp habitat edges, as defined by discrete changes in soils and plants, are not edges but broad transition zones for many invertebrate taxa. There are several implications of these results, especially for landscape ecology. 相似文献
933.
Abstract Acacia suaveolens (Sm.) Willd is a perennial shrub that forms even‐aged stands, recruited from a soil seed‐bank following fire. It has previously been subject to demographic studies, which used a space‐for‐time substitution to investigate temporal patterns following fire. In the present study the potential for spatial variation across sites was investigated by sampling at several similarly aged populations in Ku‐ring‐gai Chase National Park, northern Sydney, Australia. Significant variation in mean size and fecundity of A. suaveolens individuals was observed among sites, over a 2‐4.6‐fold range in plant size, and a sevenfold range in mean fecundity. The observed variation at 3 years after fire encapsulated most of the variation previously observed among sites 0‐17 years since fire, emphasizing the importance of spatial variation in this species. For each site a two‐stage (seed, plant) matrix model was constructed, and projected from 3 to 25 years following fire. Population growth was measured as number of seeds per 3‐year‐old plant, and found to vary 1.4‐fold across models for different sites. This site‐to‐site variation, as well as that in size, fecundity and survival, was statistically significant. Variation in projected seeds per plant could mostly be attributed to differences in fecundity rather than plant survival. Sensitivity analyses emphasized the biological significance of the variation in fecundity. Whereas previous studies have focused on temporal variation, this work demonstrates the importance of extending our understanding of a species to include the spatial component of population dynamics. 相似文献
934.
Regulation of cellular adhesion molecule expression in murine oocytes, peri-implant ation and post-implantation embryos 总被引:2,自引:0,他引:2
DAVID P LU LINA TIAN CHRIS O'''' NEILL NICHOLAS JC KING Department of Pathology University of Sydney NSW AustraliaHuman Reproduction Unit Department of Physiology University of Sydney Royal North Shore Hospital NSW Australia 《Cell research》2002,(Z2)
Expression of the adhesion molecules, ICAM-1, VCAM-1, NCAM, CD44, CD49d (VLA-4, a chain), and CDlla (LFA-1, a chain) on mouse oocytes, and pre- and peri-implantation stage embryos was examined by quantitative indirect immunofluorescence microscopy. ICAM-1 was most strongly expressed at the oocyte stage, gradually declining almost to undetectable levels by the expanded blastocyst stage. NCAM, also expressed maximally on the oocyte, declined to undetectable levels beyond the morula stage. On the other hand, CD44 declined from highest expression at the oocyte stage to show a second maximum at the compacted 8-cell/morula. This molecule exhibited high expression around contact areas between trophecto-derm and zona pellucida during blastocyst hatching. CD49d was highly expressed in the oocyte, remained significantly expressed throughout and after blastocyst hatching was expressed on the polar trophecto-derm. Like CD44, CD49d declined to undetectable levels at the blastocyst outgrowth stage. Expression of both 相似文献
935.
The state of play of farmland birds: population trends and conservation status of lowland farmland birds in the United Kingdom 总被引:10,自引:2,他引:8
Many bird species of lowland farmland have declined substantially in the United Kingdom over the past 30 years. Declines among farmland specialists are steeper than for generalists and were most rapid for these specialists in the 1970s and 1980s. These changes have been linked to increased agricultural intensification and are reflected in Red or Amber conservation concern status for many common farmland species, as well as for rarer ones. We review long- and short-term population trends and the conservation status of lowland farmland birds in the UK using the latest available information from bird surveys, and examine patterns among species. Analyses of demographic parameters suggest broadly that the key factor driving population changes of seed-eating and migrant birds is overwinter survival, whereas for many non-passerine species population growth appears to be limited by productivity. Population trends for a suite of lowland farmland species were first combined in the UK Government's headline wild bird indicator published in 1998. This 'Skylark index' as it is sometimes known was intended to reflect the health of the wider countryside and struck a chord with the public and decision-makers. We look at the behaviour of the composite indicator and explore the population dynamics of the increasing and declining species separately. Simple models of population growth in these groups are then used to explore plausible scenarios for delivering the Government's Public Service Agreement target to reverse the long-term decline in the number of farmland birds by 2020. 相似文献
936.
937.
Archaeophytes in Britain 总被引:5,自引:0,他引:5
CHRISTOPHER D. PRESTON DAVID A. PEARMAN ALLAN R. HALL 《Botanical journal of the Linnean Society. Linnean Society of London》2004,145(3):257-294
The concept of 'archaeophytes' (alien taxa which became established in a study area before AD 1500) is widely used in floristic analyses in central and northern Europe, but few authors have applied it to the British flora. Six criteria for the recognition of archaeophytes are outlined, drawing upon evidence of fossil and recent history, current habitat and European and extra-European distribution. These are used to identify 157 probable archaeophytes in Britain. Only five of these are known from fossil records from the Neolithic; most are first recorded in archaeological contexts in the Late Bronze Age, Iron Age, Roman or Medieval periods. As a group, archaeophytes (unlike neophytes) have declined in Britain in the 20th century. Comparison of the accepted status of these species in the Czech Republic, Germany, Poland and Finland demonstrates that over 50% are treated as archaeophytes in central Europe, but in Finland many are absent or only present as casual introductions. Species regarded as archaeophytes in these countries but as natives in Britain are also reviewed. The indirect nature of the evidence used to identify archaeophytes means that it is usually impossible to be certain about the history of a species; in particular, archaeophytes which have successfully invaded semi-natural habitats are likely to be overlooked as natives. The suggestion that a species is an archaeophyte is best regarded as a hypothesis to be tested by further studies. There is considerable scope for archaeological investigations aimed at addressing these botanical problems. © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 145 , 257−294. 相似文献
938.
DAVID J. HORNE ROBIN J. SMITH JOHN E. WHITTAKER JOHN W. MURRAY 《Zoological Journal of the Linnean Society》2004,142(2):253-288
Terrestricythere elisabethae sp. nov. is described from a semiterrestrial coastal habitat at two sites in Hampshire, southern England. It is the first record of a living population of the genus outside the Far East (north-west Pacific). Based on extensive collections and from observations of cultures, its morphology is described (including a formal definition of the unique 'visordont' hinge), as well as its ontogeny and lifestyle (encompassing habitat, life cycle, mode of life and locomotion). A further new species from Somerset, south-west England is also recorded on the basis of a single specimen but left in open nomenclature. The affinities of the Terrestricytheroidea are discussed in the context of a tentative phylogeny of podocopan Ostracoda. Both carapace and appendage characters are such as to warrant maintaining it as a separate superfamily, which is more closely related to the Cytheroidea and Darwinuloidea than to the Cypridoidea. © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society , 2004, 142 , 253–288. 相似文献
939.
JESS W. JONES MELANIE CULVER VICTOR DAVID JENNIFER STRUTHERS NATHAN A. JOHNSON RICHARD J. NEVES STEPHEN J. O'BRIEN ERIC M. HALLERMAN 《Molecular ecology resources》2004,4(4):649-652
Primers for 10 polymorphic microsatellite loci were developed and characterized for the endangered oyster mussel Epioblasma capsaeformis from the Clinch River, Tennessee. Microsatellite loci also were tested in four other populations or species. Amplification was successful for most loci in these closely related endangered species or populations; therefore, a high level of flanking sequence similarity was inferred for this group of species and populations. Allelic diversity ranged from nine to 20 alleles/locus, and averaged 13.6/locus. This study demonstrated the feasibility of using polymerase chain reaction (PCR) primers to amplify microsatellite loci across freshwater mussel species to conduct population genetics studies. 相似文献
940.
Tracing the tropics across land and sea: Permian to present 总被引:1,自引:0,他引:1
ALFRED ZIEGLER GIDON ESHEL P. McALLISTER REES THOMAS ROTHFUS DAVID ROWLEY DAVID SUNDERLIN 《Lethaia: An International Journal of Palaeontology and Stratigraphy》2003,36(3):227-254
The continuity through the past 300 million years of key tropical sediment types, namely coals, evaporites, reefs and carbonates, is examined. Physical controls for their geographical distributions are related to the Hadley cell circulation, and its effects on rainfall and ocean circulation. Climate modelling studies are reviewed in this context, as are biogeographical studies of key fossil groups. Low-latitude peats and coals represent everwet climates related to the Intertropical Convergence Zone near the Equator, as well as coastal diurnal rainfall systems elsewhere in the tropics and subtropics. The incidence of tropical coals and rainforests through time is variable, being least common during the interval of Pangean monsoonal climates. Evaporites represent the descending limbs of the Hadley cells and are centred at 10° to 40° north and south in latitudes that today show an excess of evaporation over precipitation. These deposits coincide with the deserts as well as seasonally rainy climates, and their latitudinal ranges seem to have been relatively constant through time. Reefs also can be related to the Hadley circulation. They thrive within the regions of clear water associated with broad areas of downwelling which are displaced toward the western portions of tropical oceans. These dynamic features are ultimately driven by the subtropical high-pressure cells which are the surface signature of the subsiding branches of the Hadley circulation. Carbonates occupy the same areas, but extend into higher latitudes in regions where terrestrial surface gradients are low and clastic runoff from the land is minimal. We argue that the palaeo-latitudinal record of all these climate-sensitive sediment types is broadly similar to their environments and latitudes of formation today, implying that dynamic effects of atmospheric and oceanic circulation control their distribution, rather than temperature gradients that would expand or contract through time. 相似文献