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111.
Tetrasomy 12p (Pallister-Killian syndrome) is a mosaic aneuploidy syndrome in which the isochromosome is present in amniocytes with a much greater percentage than fetal lymphocytes. Two new cases identified by prenatal diagnosis are reported. Indications for prenatal diagnosis were advanced maternal age and fetal anomalies. The most consistent reported prenatal ultrasound findings for tetrasomy 12p include polyhydramnios with short femurs and a diaphragmatic hernia. Recognition of congenital malformation patterns prenatally may allow appropriate selection of tissue for chromosome analysis. Molecular cytogenetic analysis using fluorescence in situ hybridization was used retrospectively to confirm the presence of the isochromosome 12p in various formalin-fixed fetal tissues. The levels of mosaicism detected in fetal and placental tissues were lower than those detected prenatally.  相似文献   
112.
Green lanes are unmetalled tracks between fields of variable width, which may be sunk below or raised above field level, and bounded on both sides by ‘grass’ banks, hedgerows or dry-stone walls. In the UK they have no unique planning status and have been overlooked as discrete landscape elements. Green lanes were surveyed for butterflies in 1997 on lowland arable farmland on the Trafford/north Cheshire border (Warburton) and on upland grassland in the Yorkshire Dales (Ribble Valley). At the lowland site the green lanes were bounded by vegetation and were compared with grass banks and single hedgerow field boundaries; at the upland farm, the green lanes were bounded by dry-stone walls and were compared with grass banks and single dry-stone walls. Data from earlier work on a largely arable farm (Manydown) in Hampshire in 1987 and 1988 were re-analysed to make comparisons between a green lane, the rides and glades of two coppiced woodlands, and the grass banks and single hedgerows surrounding arable fields. Green lanes, whether bounded by vegetation or stone were superior to other common farmland biotopes with the exception of woodland, in terms of both butterfly abundance and species richness.Multiple regression of the Warburton data indicated the importance of green lanes, adjacent habitat type, and nectar sources for species richness and butterfly abundance. The interior of green lanes had lower windspeeds, and more bramble nectar sources than hedgerows or grass banks. By their nature they occupy a larger area of uncropped land, and are subject to a reduced disturbance regime and reduced inputs of agrochemicals and fertilisers. Their value as biodiversity reservoirs in intensively managed land is likely to be high.  相似文献   
113.
This paper presents a brief review of the international scientific literature of polybrominated diphenyl ethers (PBDEs) and polybrominated biphenyls (PBBs) in sewage sludge and a survey of these compounds in sewage sludge from 16 Australian wastewater treatment plants (WWTPs). The SigmaPBDE mean concentration in the Australian study was 1137microgkg(-1) dry weight (d.w.) (s.d. 1116) and ranged between 5 and 4 230microgkg(-1)d.w. The urban mean of 1308microgkg(-1) (s.d. 1320) and the rural mean of 911microgkg(-1) (s.d. 831) are not statistically different and are similar to levels in European sludges. Principal components analysis was performed on the data set and revealed that 76% of the data variation could be explained by two components that corresponded to overall concentration of the pentaBDE and the decaBDE commercial formulations. An analysis of variance was performed comparing PBDEs levels at three WWTPs over the years 2005 and 2006, finding differences between treatment plants (BDE-47) but no significant difference in PBDE levels in the years 2005 and 2006. Low levels of BB-153 were detected in all samples of this survey (n=16); mean 0.6microgkg(-1)d.w. (s.d. 0.5). This compound has rarely been reported in any other study of sewage sludges undertaken outside Australia. This work highlights the need for a risk assessment of PBDEs in sewage sludge when used for land application, taking into account typical levels found in Australian sludges and soils.  相似文献   
114.
Compassionate conservation focuses on 4 tenets: first, do no harm; individuals matter; inclusivity of individual animals; and peaceful coexistence between humans and animals. Recently, compassionate conservation has been promoted as an alternative to conventional conservation philosophy. We believe examples presented by compassionate conservationists are deliberately or arbitrarily chosen to focus on mammals; inherently not compassionate; and offer ineffective conservation solutions. Compassionate conservation arbitrarily focuses on charismatic species, notably large predators and megaherbivores. The philosophy is not compassionate when it leaves invasive predators in the environment to cause harm to vastly more individuals of native species or uses the fear of harm by apex predators to terrorize mesopredators. Hindering the control of exotic species (megafauna, predators) in situ will not improve the conservation condition of the majority of biodiversity. The positions taken by so-called compassionate conservationists on particular species and on conservation actions could be extended to hinder other forms of conservation, including translocations, conservation fencing, and fertility control. Animal welfare is incredibly important to conservation, but ironically compassionate conservation does not offer the best welfare outcomes to animals and is often ineffective in achieving conservation goals. Consequently, compassionate conservation may threaten public and governmental support for conservation because of the limited understanding of conservation problems by the general public.  相似文献   
115.
This paper presents results from laboratory studies to measure the methane yield and rate of digestion of reject bananas. These parameters were determined in experiments that took into account the likely configuration of a full-scale plant in the banana growing region of north Queensland. The digestion was conducted in a 200-l reactor using fed-batch operation, relying entirely on the natural microbial consortia on the reject bananas to avoid reliance on external inocula such as sludge, an undesirable material around food packaging facilities. An enrichment culture was first established in a highly buffered 200-l batch digestion unit. The fed-batch digester was then started by exchanging leachate with the mature batch reactor. Under loading conditions of 0.6 kg VS m(-3)d(-1) over 70 days where the average working volume was 160 l, the digester produced 398+/-20 l CH4 kg VS(-1). Increasing the loading rate to 1.6 kg VS m(-3)d(-1) resulted in a reduced methane yield of 210 l CH4 kg VS(-1) over 23 days of operation, with a concomitant accumulation of banana waste in the digester. The leachate at the end of digestion contained over 4000 mg l(-1)K, 200 mg l(-1) N and 75 mg l(-1), levels that exceed acceptable limits for general agricultural irrigation.  相似文献   
116.
Mankind needs to use the resources and opportunities offered by the marine environment while protecting ecological processes and systems. This is the foundation for sustainable development, which can only be achieved by adopting an appropriate management approach. Whether internationally or at a regional scale, successful management of marine ecosystems needs to be based on a scientifically robust approach to monitoring environmental change. Within such a framework, the conservation of marine biological diversity is problematic, as many conventional measures of diversity are not appropriate for measuring the types of change that require management. New indicators are required and in this paper we summarise some of the current methodology being used to derive such indices, which may be used to evaluate the effectiveness of marine stewardship initiatives. Through a series of examples we demonstrate the application of the taxonomic distinctness indicator of biodiversity to marine environmental assessment and its development towards becoming an operational tool.  相似文献   
117.
A series of batch, slurry anaerobic digestion experiments were performed where the soluble and insoluble fractions, and unwashed MSW were separately digested in a 200l stirred stainless steel vessel at a pH of 7.2 and a temperature of 38 degrees C. It was found that 7% of the total MSW COD was readily soluble, of which 80% was converted to biogas; 50% of the insoluble fraction was solubilised, of this only 80% was converted to biogas. The rate of digesting the insoluble fraction was about four times slower than the rate of digesting the soluble fraction; 48% of the total COD was converted to biogas and 40% of the total nitrogen was converted to ammonia. Soluble and insoluble fractions were broken down simultaneously. The minimum time to convert 95% of the degradable fraction to biogas was 20 days. The lag phase for the degradation of insoluble fraction of MSW can be overcome by acclimatising the culture with the soluble fraction. The rate of digestion and the methane yield was not affected by particle size (within the range of 2-50mm). A dynamic model was developed to describe batch digestion of MSW. The parameters of the model were estimated using data from the separate digestion of soluble and insoluble fractions and validated against data from the digestion of unwashed MSW. Trends in the specific aceticlastic and formate-utilising methanogenic activity were used to estimate initial methanogenic biomass concentration and bacterial death rate coefficient. The kinetics of hydrolysis of insoluble fraction could be adequately described by a Contois equation and the kinetics of acidogenesis, and aceticlastic and hydrogen utilising methanogenesis by Monod equations.  相似文献   
118.
The reproductive and larval biology of the common Antarctic cushion-star Odontaster validus Koehler (Echinodermata: Asteroidea) were studied in a shallow-water population at Signy Island in the maritime Antarctic. The gonad index peaked in April/May, and injection with 1-methyladenine indicated that competence to spawn peaked in May/June. Gastrulae were first detected in May, and maximal water-column larval densities were measured in July. Reproduction was therefore highly seasonal, although not all individuals appeared to spawn each year. The pyloric caeca index increased in summer (typically November to March, but variable between years) and decreased during winter (June to October), suggesting that feeding activity was seasonal. All aspects of biology investigated showed significant interannual variability. Comparison with previous studies in the high Antarctic at McMurdo Sound indicated a similar if more pronounced seasonality at Signy, but the warmer seawater temperatures in the maritime Antarctic (particularly in late winter/early spring from September onwards) resulted in faster larval development at Signy. Received: 21 April 1997 / Accepted: 28 January 1998  相似文献   
119.
Historical records of sand drift and dune-building along the coastline of Western Europe provide insights into the natural processes of sand dune accretion and both the impacts of, and human responses to, sand incursions. The analysis of documentary records, instrumental data and proxy records over the last 1,000 years indicates that this period, which included the Little Ice Age (AD 1570–1900), featured numerous episodes of sand drift and dune development driven by strong winds associated with Atlantic storms. It is estimated that sand drift affected over a quarter of a million hectares of coastal land in Western Europe. The widespread use of vegetation to stabilise coastal dune systems and prevent sand drift is documented across Europe from AD 1100 and by the start of the 20th century all of the larger coastal dune systems in Portugal, France, Britain and Denmark were comparatively inactive. Given that Atlantic storminess has remained more or less unchanged over the last 200 years, modern dune management strategies which consider dune devegetation, driven by an increasing focus on ‘naturalness’, may give rise to a recurrence of sand drift problems. Predictions of increased storm frequencies by the end of the 21st century, coupled with sea level rise and potential changes in sand supply will present further challenges for the more ‘dynamic’ dune management strategies.  相似文献   
120.
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