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Being Highest (being + highest)
Selected AbstractsThe regional variation of aboveground live biomass in old-growth Amazonian forestsGLOBAL CHANGE BIOLOGY, Issue 7 2006YADVINDER MALHI Abstract The biomass of tropical forests plays an important role in the global carbon cycle, both as a dynamic reservoir of carbon, and as a source of carbon dioxide to the atmosphere in areas undergoing deforestation. However, the absolute magnitude and environmental determinants of tropical forest biomass are still poorly understood. Here, we present a new synthesis and interpolation of the basal area and aboveground live biomass of old-growth lowland tropical forests across South America, based on data from 227 forest plots, many previously unpublished. Forest biomass was analyzed in terms of two uncorrelated factors: basal area and mean wood density. Basal area is strongly affected by local landscape factors, but is relatively invariant at regional scale in moist tropical forests, and declines significantly at the dry periphery of the forest zone. Mean wood density is inversely correlated with forest dynamics, being lower in the dynamic forests of western Amazonia and high in the slow-growing forests of eastern Amazonia. The combination of these two factors results in biomass being highest in the moderately seasonal, slow growing forests of central Amazonia and the Guyanas (up to 350 Mg dry weight ha,1) and declining to 200,250 Mg dry weight ha,1 at the western, southern and eastern margins. Overall, we estimate the total aboveground live biomass of intact Amazonian rainforests (area 5.76 × 106 km2 in 2000) to be 93±23 Pg C, taking into account lianas and small trees. Including dead biomass and belowground biomass would increase this value by approximately 10% and 21%, respectively, but the spatial variation of these additional terms still needs to be quantified. [source] CO2 exchange in three Canadian High Arctic ecosystems: response to long-term experimental warmingGLOBAL CHANGE BIOLOGY, Issue 12 2004Jeffrey M. Welker Abstract Carbon dioxide exchange, soil C and N, leaf mineral nutrition and leaf carbon isotope discrimination (LCID-,) were measured in three High Arctic tundra ecosystems over 2 years under ambient and long-term (9 years) warmed (,2°C) conditions. These ecosystems are located at Alexandra Fiord (79°N) on Ellesmere Island, Nunavut, and span a soil water gradient; dry, mesic, and wet tundra. Growing season CO2 fluxes (i.e., net ecosystem exchange (NEE), gross ecosystem photosynthesis (GEP), and ecosystem respiration (Re)) were measured using an infrared gas analyzer and winter C losses were estimated by chemical absorption. All three tundra ecosystems lost CO2 to the atmosphere during the winter, ranging from 7 to 12 g CO2 -C m,2 season,1 being highest in the wet tundra. The period during the growing season when mesic tundra switch from being a CO2 source to a CO2 sink was increased by 2 weeks because of warming and increases in GEP. Warming during the summer stimulated dry tundra GEP more than Re and thus, NEE was consistently greater under warmed as opposed to ambient temperatures. In mesic tundra, warming stimulated GEP with no effect on Re increasing NEE by ,10%, especially in the first half of the summer. During the ,70 days growing season (mid-June,mid-August), the dry and wet tundra ecosystems were net CO2 -C sinks (30 and 67 g C m,2 season,1, respectively) and the mesic ecosystem was a net C source (58 g C m,2 season,1) to the atmosphere under ambient temperature conditions, due in part to unusual glacier melt water flooding that occurred in the mesic tundra. Experimental warming during the growing season increased net C uptake by ,12% in dry tundra, but reduced net C uptake by ,20% in wet tundra primarily because of greater rates of Re as opposed to lower rates of GEP. Mesic tundra responded to long-term warming with ,30% increase in GEP with almost no change in Re reducing this tundra type to a slight C source (17 g C m,2 season,1). Warming caused LCID of Dryas integrafolia plants to be higher in dry tundra and lower in Salix arctic plants in mesic and wet tundra. Our findings indicate that: (1) High Arctic ecosystems, which occur in similar mesoclimates, have different net CO2 exchange rates with the atmosphere; (2) long-term warming can increase the net CO2 exchange of High Arctic tundra by stimulating GEP, but it can also reduce net CO2 exchange in some tundra types during the summer by stimulating Re to a greater degree than stimulating GEP; (3) after 9 years of experimental warming, increases in soil carbon and nitrogen are detectable, in part, because of increases in deciduous shrub cover, biomass, and leaf litter inputs; (4) dry tundra increases in GEP, in response to long-term warming, is reflected in D. integrifolia LCID; and (5) the differential carbon exchange responses of dry, mesic, and wet tundra to similar warming magnitudes appear to depend, in part, on the hydrologic (soil water) conditions. Annual net ecosystem CO2 -C exchange rates ranged from losses of 64 g C m,2 yr,1 to gains of 55 g C m,2 yr,1. These magnitudes of positive NEE are close to the estimates of NPP for these tundra types in Alexandra Fiord and in other High Arctic locations based on destructive harvests. [source] Postmarketing surveillance study of KOGENATE® Bayer with Bio-Set® in patients with haemophilia A: evaluation of patients' satisfaction after switch to the new reconstitution systemHAEMOPHILIA, Issue 1 2010N. VIDOVIC Summary., KOGENATE® Bayer (rFVIII-FS) with Bio-Set® is designed to prevent patient contact with exposed needles during recombinant factor VIII reconstitution. This postmarketing surveillance study evaluated patient satisfaction before and after switching to the new Bio-Set reconstitution method. Male children and adults with haemophilia A were enrolled from nine European countries. A preference questionnaire was administered to patients after Bio-Set training and at the end of the observation period (,20 exposure days or 3 months). Physician assessments of patient compliance and satisfaction were conducted at the end of the observation period. Patients (N = 306) received a mean ± SD of 28 ± 23 infusions of rFVIII-FS with Bio-Set. A majority of patients (82%) preferred the Bio-Set method, with domain scores for ease of use, safety from needlesticks, and speed of reconstitution being highest after training and at the end of the observation period. The Bio-Set method received higher mean scores than previous reconstitution methods for worry/safety and ease/confidence domains at both time points. Physician-reported patient compliance with the Bio-Set method was similar or greater compared with the previous method for 94% of the patients, with physicians reporting that 92% of the patients were satisfied or very satisfied with Bio-Set. Thirteen adverse events (AEs) occurred in nine patients, and five serious AEs occurred in five patients; none was related to rFVIII-FS. No de novo or recurrent inhibitor development was observed during the observation period. rFVIII-FS with Bio-Set was well tolerated and well accepted by haemophilia A patients, which may improve treatment compliance. [source] Parents' Evaluation of Developmental Status in the Australian day-care setting: Developmental concerns of parents and carersJOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 1 2003D Coghlan Objective: To trial the Parents' Evaluation of Developmental Status (PEDS) as an instrument for reporting developmental concerns for Australian preschool children. Method: A cross-sectional survey of parents and carers of 262 children attending five day-care centres and two kindergartens in Melbourne was conducted between October and November 1999. Parents and carers completed the written PEDS questionnaire, comprising 10 questions eliciting concerns about learning, development and behaviour, and answered questions about the acceptability and use of the PEDS. Results: Of 445 children, 389 were eligible for inclusion. Complete parent and carer PEDS data were available for 262 children (67% response: 47% boys; 53% girls) aged from 18 months to 5 years, 9 months. Most parents found the PEDS questionnaire easy to complete (98%) and likely to be useful to health professionals (89%). Twenty-four children (9%) were classified as being at high-risk of disabilities and 49 (19%) were classified as being at medium-risk of disabilities. Parents of 125 children (48%) reported no concerns. The prevalence of parental concerns was similar to the USA norming sample. Carers reported similar prevalences of concerns. Although overall agreement was high, parent/carer ,-values were modest, being highest for the gross motor (, = 0.40) and social,emotional (, = 0.37) domains. Conclusions: The PEDS is acceptable to parents of Australian preschool children, with a prevalence of significant concerns (i.e. children at high- and medium-risk of developmental problems) that is similar to those in the USA. Further research is needed to assess what factors differentially influence whether a concern is felt in a particular domain for a particular child. [source] Demographic Characteristics of Lytechinus variegatus (Echinoidea: Echinodermata) from Three Habitats in a North Florida Bay, Gulf of MexicoMARINE ECOLOGY, Issue 1 2000Steven D. Beddingfield Abstract. The population densities, spatial distributions, size frequencies, growth rates, longevity and reproductive activities of sub-populations of the sea urchin Lytechinus variegatus were investigated over a two-year period. Sea urchins were examined in three habitats in Saint Joseph Bay, Florida, which is within the northern limits of their distribution. Densities of sea urchins, which ranged as high as 35 individuals ·,2, fluctuated seasonally at all sites and were higher in seagrass beds comprised of Thalassia testudinum than Syringodium filiforme or on a sand flat. A cold front caused large-scale, catastrophic mortality among adult, and especially juvenile, sea urchins in nearshore habitats of the Bay in the spring of 1993, leading to a dramatic decline in sea urchin densities at the Thalassia seagrass site. The population recovered over 6 months at this site and was attributable to immigration of new adults. Juvenile recruitment displayed both interannual and site-specific variability, with recruitment being highest in seagrass habitats in fall and spring. The most pronounced recruitment event occurred in fall 1993 at the Thalassia site. Spatial distributions of adult individuals ascertained monthly never varied from random in the seagrass beds (T. testudinum and S. filiforme) or during spring, summer or fall months on the sand flat. Nonetheless, aggregations of adult sea urchins were observed on the sand flat in the winter months and were associated with patchy distributions of plant food resources. Juvenile sea urchins (< 25 mm test diameter) exhibited aggregations at all sites and 67 % of all juveniles under 10 mm test diameter (91 of 165 individuals observed) were found under the spine canopies of adults. Measurements of the inducibility of spawning indicated peak gametic maturity in all three sub-populations in spring and summer. Gonad indices varied between habitats and years, but distinct maxima were detected, particularly in spring 1993 and late summer 1994. The mean gonad index of individuals at the Syringodium seagrass site was 2- to 4-fold higher than the other sites in spring 1993 and gonad indices were much higher at all sites in spring of 1993 than 1994. Estimates of growth based on changes in size frequency cohorts coupled with measurements of growth bands on lantern demipyramids indicated that L. variegatus in three habitats of Saint Joseph Bay have similar growth rates and attain a mean test diameter of approximately 35 mm in one year. In contrast to populations within the central biogeographical range of the species, which may attain test diameters up to 90 mm, the largest individuals recorded in Saint Joseph Bay were 60 mm in test diameter, and almost all individuals were no more than 45 mm in test diameter or two years of age. The demographics of L. variegatus in the northern limits of their distribution appear to be strongly influenced by latitudinally driven, low-temperature events and secondarily by local abiotic factors, especially springtime low salinities, which may negatively impact larval development and recruitment. [source] Comparative trends in cause-specific fetal and neonatal mortality in twin and singleton births in the North of England, 1982,1994BJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 4 2000Public Health), Svetlana V. Glinianaia Research Associate (Epidemiology Objective To examine trends in cause- and birthweight-specific fetal and neonatal mortality rates in twins and singletons. Design Descriptive analysis based on a regional register. Setting The Northern Health Region of England, 1982,1994. Sample Two hundred and thirty-six fetal and 356 neonatal twin deaths; 2687 fetal and 2301 neonatal singleton deaths from a population of 10,734 twins and 505,477 singletons. Main outcome measures Fetal and neonatal autopsy rates, cause- and birthweight-specific fetal and neonatal mortality rates in twins and singletons. Results The extended perinatal mortality (including stillbirths and neonatal deaths) rate (EPMR) was 55.2 per 1000 in 1982,1994 in twins compared with 9.9 per 1000 in singletons. The relative risk for twin compared with singleton deaths was 5.6 (95% CI 5.1-6.1) being highest for immaturity (12.9, 95% CI 11.1,15.0). A significant decrease in the EPMR occurred in both twins and singletons in 1988,1994 compared with 1982,1987. The EPMR decreased mainly due to a reduction of deaths from antepartum asphyxia in twins and intrapartum asphyxia and trauma in singletons, as well as a reduction in congenital malformations in both groups. In both twins and singletons, birthweight-specific mortality rates improved between 1982,1987 and 1988,1994. Conclusion The higher relative risk for twin deaths remained stable due to a similar decrease in the EPMR for both twins and singletons. The cause-specific relative risk in twins declined for antepartum asphyxia. The mortality rate resulting from lethal congenital malformations decreased in twins and singletons mainly due to earlier detection and subsequent termination of pregnancy. [source] | |||||||||||||