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101.
102.
This study evaluated the effects of storage in northern winter conditions (5 degrees C) on the characteristics and nutrients separation of digestates from co-digestion of manure and biowaste as well as the hygienic quality of the digestates after digestion and storage. During 3-11 months' storage average nitrogen losses and reductions of total solids (TS) and volatile solids (VS) were 0-15%. With some exceptions, soluble chemical oxygen demand (SCOD) had increased slightly (from approximately 6.5 to approximately 7.5g/l) after 3 months' storage, while after 9-11 months' it had decreased from 8.3-11 to 5.6-8.4g/l. The concentrations of P(tot) and PO4-P in the separated liquid fractions decreased 40-57% after 3 months' storage and 71-91% after 9 months' storage compared to the initial concentrations. The methane potential losses during 9-11 months' storage corresponded 0-10% of the total methane potential without storage. The hygienic quality of the digestates from the 55 degrees C reactor and during storage fulfilled the Animal By-Products Regulation (ABPR) demands while the 35 degrees C digestate contained 0-105cfu/g of indicator bacteria (faecal coliforms, enterobacteria, enterococcus) and >10cfu/g of spiked salmonella, which amounts decreased slowly during storage. Sulphite reducing clostridia was not affected by either digestion or storage. 相似文献
103.
Summary The steroid 21-hydroxylase enzyme (P450c21) is a member of the cytochrome P450 gene superfamily and is essential in the synthesis of cortisol and aldosterone. Defects in the P450c21B gene cause congenital adrenal hyperplasia (CAH), a common genetic disorder leading to virilization of newborn females. To avoid the standard cloning of mutant P450c21 genes from genomic libraries, we amplified the full-length genomic P450c21 genes by polymerase chain reaction (PCR). The amplification was followed by cloning and sequencing of a defective P450c21B gene. The strategy described here is generally applicable, thus making a simple characterization of the complete P450c21B gene possible. The method was tested in one patient suffering from the simple virilizing form of CAH. The sequence of three independent clones originating from the defective P450c21B showed that Ile at position 172 in exon 4 was substituted by Asn. The identical mutation also has been found in other patients with CAH. 相似文献
104.
Virulence of parasites in hosts under environmental stress: experiments with anoxia and starvation 总被引:4,自引:0,他引:4
Most environments periodically impose severe stress that may cause high mortality and alter population structure, for example, by removing sick and old individuals. We examined how anoxic conditions and starvation of the host affect virulence of two closely related trematode parasites, Rhipidocotyle campanula and R. fennica . These parasites differ by prevalence of infection and by exploitation rate of individual hosts (freshwater clam, Anodonta piscinalis ). Infection by R. campanula is rare (<5% prevalence of infection) and destroys on average 90% of the gonad tissue of the individual host. Infection by R. fennica is more common (20–60% prevalence of infection) and leads to on average 30% gonad destruction. In the end, both infections lead to host infertility. We predicted that R. campanula induces higher host mortality than R. fennica under host stress. In two laboratory experiments, we exposed naturally-infected and uninfected clams to anoxia and to starvation. Anoxia occasionally takes place during winter in eutrophic lakes, while some degree of starvation should occur seasonally. We found that mortality rate of clams was much higher under anoxia than under starvation, and that infection increased mortality rate under both types of host stress. As predicted, R. campanula induced higher host mortality than R. fennica . Host survival was population-specific, suggesting that clams of different origins carried different amount of energy reserves. Severe environmental perturbation may remove R. campanula infected individuals from the host population, but recolonization from the fish host is likely to prevent extinction of the parasite suprapopulation. The observed high host mortality induced by R. campanula may be one ecological explanation for the consistently lower prevalence of infection of R. campanula when compared to R. fennica . 相似文献
105.
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107.
Yves T. Prairie Jukka Alm Jake Beaulieu Nathan Barros Tom Battin Jonathan Cole Paul del Giorgio Tonya DelSontro Frédéric Guérin Atle Harby John Harrison Sara Mercier-Blais Dominique Serça Sebastian Sobek Dominic Vachon 《Ecosystems》2018,21(5):1058-1071
Freshwater reservoirs are a known source of greenhouse gas (GHG) to the atmosphere, but their quantitative significance is still only loosely constrained. Although part of this uncertainty can be attributed to the difficulties in measuring highly variable fluxes, it is also the result of a lack of a clear accounting methodology, particularly about what constitutes new emissions and potential new sinks. In this paper, we review the main processes involved in the generation of GHG in reservoir systems and propose a simple approach to quantify the reservoir GHG footprint in terms of the net changes in GHG fluxes to the atmosphere induced by damming, that is, ‘what the atmosphere sees.’ The approach takes into account the pre-impoundment GHG balance of the landscape, the temporal evolution of reservoir GHG emission profile as well as the natural emissions that are displaced to or away from the reservoir site resulting from hydrological and other changes. It also clarifies the portion of the reservoir carbon burial that can potentially be considered an offset to GHG emissions. 相似文献
108.
Congenital adrenal hyperplasia (CAH) due to steroid 21-hydroxylase deficiency is a common inherited defect of adrenal steroid
hormone biosynthesis. Unusually for genetic disorders, the majority of mutations causing CAH apparently result from recombinations
between the CYP21 gene encoding the 21-hydroxylase enzyme and the closely linked, highly homologous pseudogene CYP21P. The
CYP21 and CYP21P genes are located in the major histocompatibility complex class III region on chromosome 6p21.3. We analyzed
the mutations and recombination breakpoints in the CYP21 gene and determined the associated haplotypes in 51 unrelated Finnish
families with CAH. They represent no less than half of all CYP21 deficiency patients in Finland. The results indicate the
existence of multiple founder mutation-haplotype combinations in the population of Finnish CAH patients. The three most common
haplotypes constituted half of all affected chromosomes; only one-sixth of the haplotypes represented single cases. Each of
the common haplotypes was shown consistently to carry a typical CYP21 mutation and only in some cases was additional variation
observed. Surprisingly, comparisons with previous published data revealed that several of the frequent mutation-haplotype
combinations in Finland are in fact also found in many other populations of patients of European origin, thus suggesting that
these haplotypes are of ancient origin. This is in clear contrast to many reports, including the present one, where a high
frequency of de novo mutations in the CYP21 gene has been reported. In addition, two unique sequence aberrations in CYP21
(W302X and R356Q), not known to exist in the CYP21P pseudogene, were detected.
Received: 5 September 1996 / Revised: 11 November 1996 相似文献
109.
To the extent that environmental impacts are the consequence of the magnitude of total material input into production in an economy, they can be lessened by reducing the use of materials—by concentrating on what has been called qualitative growth. This article presents a summary of Finnish resource use over the period 1960–1996 as a means of evaluating the trends in material use and providing a basis for assessments of sustainability. It adapts the technique of decomposition analysis developed in the field of energy studies to distinguish the effects of changes in aggregate economic activity ("activity effect"), composition of industrial activity ("structural effect") and materials intensity of use ("intensity effect") on a sectoral basis.p
According to the analysis presented here, materials consumption in Finland has grown substantially between 1960 and 1996 in the electricity, gas and water supply, pulp and paper production, civil engineering, and mining and quarrying sectors. In the same period, the ratio of GDP/mass of material mobilized has improved by 175 percent. Economic growth has caused the largest increases in materials use in the building of infrastructures; for example roads, waterways, means of supplying electricity, gas, and water, and in the production of paper and paper products. The least growth took place in the transport, basic metals production, and mining and quarrying sectors. 相似文献
According to the analysis presented here, materials consumption in Finland has grown substantially between 1960 and 1996 in the electricity, gas and water supply, pulp and paper production, civil engineering, and mining and quarrying sectors. In the same period, the ratio of GDP/mass of material mobilized has improved by 175 percent. Economic growth has caused the largest increases in materials use in the building of infrastructures; for example roads, waterways, means of supplying electricity, gas, and water, and in the production of paper and paper products. The least growth took place in the transport, basic metals production, and mining and quarrying sectors. 相似文献
110.
Jarna C Hannukainen Pirjo Nuutila Jaakko Kaprio Olli J Heinonen Urho M Kujala Tuula Janatuinen Tapani R?nnemaa Jukka Kapanen Merja Haaparanta-Solin Tapio Viljanen Juhani Knuuti Kari K Kalliokoski 《Journal of applied physiology》2006,101(5):1303-1311
We investigated heredity-independent effects of increased physical activity and aerobic fitness on skeletal muscle free fatty acid (FFA) uptake, perfusion, and their heterogeneity at rest and during exercise. Also, the relationship between local skeletal muscle FFA uptake and perfusion was studied. Nine young adult male monozygotic twin pairs with significant difference in physical activity [229 min (SD 156) average time spent for conditioning exercise per week in more and 98 min (SD 71) in less active twins, P = 0.013] and aerobic fitness [18% (SD 10) difference in maximum O2 uptake] between brothers were studied using positron emission tomography. Submaximal knee-extension exercise increased perfusion, FFA uptake, and oxygen uptake in quadriceps femoris muscles 6-10 times compared with resting values (P < 0.001). More active twins tended to utilize more oxygen, while no differences were found in muscle perfusion or FFA uptake between groups. Mean perfusion and FFA uptake correlated strongly at a whole muscle level, both at rest (r = 0.97, P = 0.03 in more and r = 0.98, P = 0.02 in less active twins) and during exercise (r = 0.99, P = 0.01 and r = 0.94, P = 0.06), but at the voxel level (87 mm3) correlation was only moderate during exercise [r = 0.73 (SD 0.08) vs. r = 0.74 (SD 0.10), P = 0.92] and weak at rest [r = 0.28 (SD 0.13) vs. r = 0.33 (SD 0.21), P = 0.58]. Exercise decreased both perfusion and FFA uptake heterogeneity within the muscles (P < 0.001) similarly in both groups. In conclusion, long-term history of moderately increased physical activity tends to enhance muscle oxidative metabolism, but it does not have any significant influence on the FFA uptake or perfusion rates or their heterogeneity in skeletal muscle. Submaximal knee-extension exercise decreases heterogeneity of muscle FFA uptake and perfusion and improves matching between local muscle perfusion and FFA uptake. Thus it seems that the genetic influence is more important to determine the heterogeneity of perfusion and FFA uptake in skeletal muscle than exercise training. 相似文献