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1.
The palaeontological, geochemical and mineralogical records of core GNS84-C106 were analysed in order to reconstruct palaeohydrological changes and palaeoproductivity patterns in the Gulf of Salerno for the last 34 kyr. This approach, including compositional analysis of planktonic and benthic assemblages, gave an insight into the relationships between continental, sea surface and bottom environmental changes. The main source of variability of planktonic and benthic assemblages is related respectively to sea surface temperature and palaeobathymetry. Interrelated changes in surface salinity, nutrients, density gradient in the water column and organic fluxes at the bottom act as a secondary factor controlling the composition of both planktonic and benthic assemblages. The highest palaeoproductivity rates were reached during an interval spanning from late glacial to Middle Holocene, in conditions of enhanced continental run-off. During the Early and Middle Holocene, reduced surface salinity and density stratification were also coupled with the development of a deep chlorophyll maximum and enhanced flux or organic matter at the bottom. From about 6.5 kyr B.P. onward, a sharp reduction in palaeoproductivity took place, coupled with an increase in surface salinities.  相似文献   

2.
    
2-DE and MALDI mass fingerprinting were used to analyse mammary tissue from lactating Friesian cows. The goal was detection of enzymes in metabolic pathways for synthesis of milk molecules including fatty acids and lactose. Of 418 protein spots analysed by PMF, 328 were matched to database sequences, resulting in 215 unique proteins. We detected 11 out of the 15 enzymes in the direct pathways for conversion of glucose to fatty acids, two of the pentose phosphate pathway enzymes and two of the enzymes for lactose synthesis from glucose. We did not detect enzymes that catalyse the first three reactions of glycolysis. Our results are typical of enzyme detection using 2-DE of mammalian tissues. We therefore advocate caution when relating enzyme abundances measured by 2-DE to metabolic output as not all relevant proteins are detected. 2-D DIGE was used to measure interindividual variation in enzyme abundance from eight animals. We extracted relative protein abundances from 2-D DIGE data and used a logratio transformation that is appropriate for compositional data of the kind represented in many proteomics experiments. Coefficients of variation for abundances of detected enzymes were 3-8%. We recommend use of this transformation for DIGE and other compositional data.  相似文献   

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4.
    
The primary goal of this study was to conduct a preliminary assessment of maggot meal protein supplements in broiler production. Maggot meal comprises 55 percent crude protein (CP), 27.65% ether extract, 8.33% Ash, 3.37 crude fiber (CF), 2.14 NFE, 94.7 percent Dry Matter, 5702 kcal/kg gross energy, and 3955 kcal/kg metabolizing energy, according to proximate analysis. Maggot meal supplementation affected broiler meat feed intake, body weight gain, FCR, dressing %, mortality, antibody titer against ND, and organoleptic features. The cost-effectiveness of maggot supplementation was also evaluated. Birds were put into four experimental groups after a week of adaptation:Control group (M0), the first experimental group (M1), the second experimental group (M2), and the third experimental group (M3), which received supplements of 0, 2, 3, and 4 g/kg, respectively. A plane ratio was given to the control group as well. The overall feed intake findings were inversely proportional to the supplementation rate. Thus, the highly supplemented group (M3) showed the lowest feed intake than the control group (M0). Bodyweight gain was directly proportional to the supplementation rate, as evident by a considerable increase in the highly supplemented group (M3) compared to the control group.  相似文献   

5.
    
Xanthomonas hortorum pv. vitians is a Gram-negative bacterium that acts as the causative agent of bacterial leaf spot and headrot in lettuce. The lipopolysaccharide (LPS) of this bacterium is suspected to be an important molecule for adhesion to the plants. We have isolated the LPS, prepared the lipid A and the polysaccharide moieties thereof, and characterised all preparations by compositional analysis. Main sugar components are rhamnose and 3-acetamido-3,6-dideoxy-galactose which presumably furnish the O-specific polysaccharide. Other sugars are mannose, glucose, 6-deoxygalactose (fucose), and galacturonic acid, which should be core region constituents, and glucosamine, which builds up the carbohydrate backbone of lipid A. The LPS contains several phosphate groups, most of which are present in the core region. The main fatty acids in the lipid A are C10:0, 3-OH-C10:0 and 3-OH-C12:0. The latter is the only amide-linked fatty acid. Two fatty acids present in small amounts were identified, C8:0 and C11:0.  相似文献   

6.
MACNAIR, M. R., 1989. A new species of Mimulus endemic to copper mines in California . The distribution and morphology of Mimulus cupriphilus , a new species restricted to two small copper mines in Calaveras County, California, is described. A comparison of flowers collected in the wild of M. guttatus and the new taxon shows that they differ considerably. These two species and three other species from the M. guttatus complex, M. nasutus, M. laciniatus and M. nudatus were grown in a glasshouse and compared. The five species were all clearly distinct. The distribution of M. cupriphilus is consistent with it having evolved comparatively recently on one or both of the two copper mines on which it is found.  相似文献   

7.
    
Two bacterial strains, P0211T and P0213T, were isolated from a sea cucumber culture pond in China. The strains were able to resist high copper levels. These two strains were characterized at the phenotypic, chemotaxonomic, and genomic level. They were completely different colors, but the 16S rRNA genes showed 99.30% similarity. Phylogenetic analysis based on the sequences of the 16S rRNA gene and five housekeeping genes (dnaK, sucC, rpoB, gyrB, and rpoD) supported the inclusion of these strains within the genus Alteromonas, and the two isolated strains formed a group separated from the closest species Alteromonas aestuariivivens KCTC 52655T. Genomic analyses, including average nucleotide identity (ANIb and ANIm), DNA–DNA hybridization (DDH), and the percentage of conserved proteins (POCP), clearly separated strains P0211T and P0213T from the other species within the genus Alteromonas with values below the thresholds for species delineation. The chemotaxonomic features (including fatty acid and polar lipid analysis) of strains P0211T and P0213T also confirmed their differentiation from the related taxa.The results demonstrated that strains P0211T and P0213T represented two novel species in the genus Alteromonas, for which we propose the names Alteromonas flava sp. nov., type strain P0211T (= KCTC 62078T = MCCC 1H00242T), and Alteromonas facilis sp. nov., type strain P0213T (= KCTC 62079T = MCCC 1H00243T).  相似文献   

8.
黄腹角雉的巢址选择   总被引:44,自引:0,他引:44  
1991 ̄1993年,在浙江省乌岩岭自然保护区对黄腹角雉的巢址选择进行了研究。野外工作共发现黄腹角雉巢15个,其中80%位于人工柳杉林中,营果树以柳杉为主,占73.3%。主成分分析表明,影响黄腹角雉巢址选择的主要因素有4种,依次为:营巢树因素(包括营巢树的高度、胸径、巢位高度和巢上方的植被盖度)、地形因素(包括坡向和坡度)、海拔因素和位置因素。  相似文献   

9.
Summary The effects of four Zn levels on the electrochemical and chemical properties of the soil solution, and on the growth and mineral nutrition of two rice varieties (IR26 and IR34) differing in tolerance to Zn deficiency were studied in the greenhouse using Zn-deficient soils from two locations. A similar experiment was conducted in culture solution to check how Zn addition affects translocation of other nutrients.In both soil and culture solution, plant Zn concentrations alone was not enough to account for varietal tolerance to Zn deficiency. Comparison of nutrient to Zn and shoot to root ratios of nutrients was more useful in determining the possible mechanism of varietal tolerance. IR 34 appeared to tolerate the disorder due to its lower Zn requirement, more efficient Zn translocation and ability to maintain lower Fe/Zn, Cu/Zn, Mg/Zn and P/Zn ratios in the shoot than the more susceptible variety, IR26. This was shown to be due to decreased translocation of Fe, Mg and P to shoots and decreased absorption of Cu by the root in IR34 in culture solution studies. Adding Zn further reduces translocation or absorption of these nutrients and depending on the nutrient supply of the soil, could cause deficiencies or mineral imbalances, especially of Fe, Cu, and P.These observed varietal differences regarding Zn requirement and the interaction of Zn with absorption and translocation of plant nutrients necessitates revision of recommendations for Zn fertilization. There is an inevitable need for Zn application in severely Zn-deficient soils regardless of rice variety. But on marginally Zn-deficient soils especially those low in Fe, Cu, or P, Zn fertilization is not advisable when resistant rice varieties are used.  相似文献   

10.
Summary Oryza coarctata, a highly salt-resistant wild rice species, is commonly found on the banks of coastal rivers in India. This species can also withstand saline water (20 to 40 dSm−1 E.C) submergence for quite a long period. It was revealed thatO. coarctata has some special unicellular salt hairs (trichomes) on the adaxial surface of the leaves, by which they efficiently maintain a low concentration of toxic salts in the plant tissue. Sodium and chloride were the dominant ions in the excreted material but they also excrete potassium, magnesium and calcium. With the increase in soil salinity sodium, magnesium and chloride excretion increased.O. coarctata maintained the optimum mineral concentration in its tissues. Maximum accumulation of potassium was observed in the leaves. With the increase in salt stress total biomass production and osmotic potential increased over control but there was no change in the moisture percentage of leaves.  相似文献   

11.
    
Nowadays great deal of research is physiological field is conducted on experimental animals and there is a lot of criticism from the wide public on methods used. Therefore, recently there is a lot of effort focused on the welfare of the animals. Main aim of this study is to determine the effect of experimental sample collection method on the selected parameters of stress. In the experiment two sample collections of rabbit blood from marginal ear vein were realized – first using standard method with one person fixing the animal and other collecting the blood using gently fixating the animal. In the second groups experimental method of inserting the experimental animal into a sack and further collection in dark was realized. During the experiment the levels of cortisol – main stress indicator in organism and other health parameters of animals including mineral profile and haematological parameters were observed. Our results show no significant changes in levels of cortisol but also a decreasing tendency in the sample from the second (dark) collection. Haematological parameters were generally in the reference values and any significant changes except levels of lymphocytes and percent of lymphocytes which shown significant increase in the second collection period were found. Also the levels of mean corpuscular haemoglobin and percent of neutrophils unveiled a significant decrease in values. Values of mineral profile parameters have indicated no significant changes except the levels of phosphorus. Based on the result we can state that the experimental sample collection has no effect on blood parameters of the animals but we spectated a statistically insignificant decrease in the levels of cortisol which can suggest that the dark collection is possibly less stressful to the animals.  相似文献   

12.
    
PurposeIn this study non-calcified plaque composition is evaluated by Dual Energy CT (DECT). Energy Dispersive X-ray Spectroscopy (EDS) has been used to study the Plaque composition. An attempt has been made to explain the DECT results with EDS analysis.MethodsThirty-two ex-vivo human cadaver coronary artery samples were scanned by DECT and data was evaluated to calculate their effective atomic number and electron density (Zeff & ρe) by inversion method. Result of DECT was compared with pathology to assess their differentiating capability. The EDS study was used to explain DECT outcome.ResultsDECT study was able to differentiate vulnerable plaque from stable with 87% accuracy (area under the curve (AUC):0.85 [95% confidence interval {CI}:0.73–0.98}] and Kappa Coefficient (KC):0.75 with respect to pathology. EDS revealed significant compositional difference in vulnerable and stable plaque at p < .05. The weight percentage of higher atomic number elements like F, Na, Mg, S, Si, P, Cl, K and Ca was found to be slightly more in vulnerable plaques as compared to a stable plaque. EDS also revealed a significantly increased weight percentage of nitrogen in stable plaques.ConclusionsThe EDS results were able to explain the outcomes of DECT study. This study conclusively explains the physics of DECT as a tool to assess the nature of non-calcified plaques as vulnerable and stable. The method proposed in this study allows for differentiation between vulnerable and stable plaque using DECT.  相似文献   

13.
Pharmaceutical aerosols have been targeted to the lungs for the treatment of asthma and pulmonary infectious diseases successfully. Micafungin (Astellas Pharma US, Deerfield, IL, USA) has been shown to be an effective antifungal agent when administrated intravenously. Pulmonary delivery of micafungin has not previously been reported. In the present pilot study, we characterize the performance of two nebulizers and their potential for delivering micafungin to the lungs as well as the use of multivariate data analysis for mass distribution profile comparison. The concentration of micafungin sodium increased by 21% when delivered by the Acorn II nebulizer and by 20% when delivered by the LC Plus nebulizer, respectively, from the first to the second sampling period. The Acorn II nebulizer delivered a fine particle fraction FPF5.8 (%<5.8 μm) of 92.5 ± 0.8 and FPF3.3 (%<3.3 μm) of 82.3 ± 2.1 during the first sampling period. For the LC Plus nebulizer, FPF5.8 was 92.3 ± 0.1 and FPF3.3 was 67.0 ± 0.7 during the first sampling period. The mass median aerodynamic diameter (MMAD) increased from 1.67 ± 0.05 to 1.77 ± 0.04 μm (Acorn II nebulizer) and from 2.09 ± 0.01 to 2.20 ± 0.01 μm (Pari LC Plus nebulizer) from the first to the second sampling periods. These changes in MMAD were statistically significant by paired t test. Multivariate data analysis showed that this could be explained systematically by greater drug deposition on stages with larger cutoff sizes and reduced drug deposition on stages with smaller cutoff sizes rather than multimodal deposition or other anomalies in size distribution.  相似文献   

14.
Assessment of copper and lipid profile in obese children and adolescents   总被引:1,自引:0,他引:1  
The aim of this study was to assess erythrocyte and plasma copper concentrations and correlate them with the lipid profile of overweight and obese children and adolescents. The study was performed with 15 over-weight and 30 obese children and adolescents, and the results were compared to the control group (21), aged 6–16 yr. Anthropometric assessment was carried out using body mass index (BMI). Total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and triglyceride serum levels were investigated. Erythrocyte and plasma copper levels were determined by atomic absorption spectrophotometry. Greater alterations in the lipid profile were observed in HDL-cholesterol, LDL-cholesterol, and triglyceride levels, with distinctions according to gender. The plasma copper concentrations in the overweight and obese male groups were significantly higher than those in the control group (p=0.0006). Negative correlations between plasma copper and total cholesterol (r=−0.54) and LDL cholesterol (r=−0.59) were observed in the obese male group. There was no statistical difference in copper erythrocyte concentrations. The obesity associated to disorders in lipid metabolism predisposes to changes in copper plasma concentrations, but there was no alteration in intracellular reserves, which suggests an important homeostatic control to compensate for plasma oscillations and metabolic alterations of the disease.  相似文献   

15.
16.
Alvarez-Valin F  Lamolle G  Bernardi G 《Gene》2002,300(1-2):161-168
In this work we re-examined the hypothesis that the variation in GC content in the human genome is due to different regional mutational biases. For this purpose we inferred the mutational pattern by using mutation databases that are available for many genes associated with human genetic diseases. The assumption of this approach is that such mutations reflect the actual frequency distribution of mutations as they arise in the population. Four classes of genes, classified according to their GC3 level, were included in this study: GC3-poor genes (GC3<45%), genes with intermediate GC3 content (45%3<60%), GC3-rich genes (60%3<75%) and very GC3-rich genes (GC3>75%). Our results show that most genes are under AT mutational biases, with very little variation compared to the expectations of neutral GC level. It is noteworthy that the mutational patterns in the GC3-rich genes do not appear to account for their GC3-richness. Instead, GC3-rich and very GC3-rich genes exhibit patterns of mutations that yield expectations of neutral GC3 content that are much lower than their actual GC3.  相似文献   

17.
Nested sample plots of three sizes (16, 1, and 1/16 sq. m) from three different studies of Norwegian coniferous forests have been subjected to DCA ordination using the same choice of options. At each sample plot size, species quantities are recorded as frequency in 16 subplots. Beta diversity, measured as length of the first DCA axis, invariably increased upon lowering of sample plot size. The same applied to the eigenvalues of the axes. This is explained as a consequence of the weakening of structure in the data matrices when the fine-grained patterns of the vegetation are emphasized.  相似文献   

18.
The knowledge of broad-scale floristic variation in wet grasslands, which are endangered throughout Europe, is still limited and some regions have remained unexplored so far. In addition, hitherto published phytosociological studies were concentrated at the national level and therefore national vegetation classifications are not consistent with each other. In order to overcome these shortcomings of traditional phytosociology, we gathered original data from Bulgaria and analysed them together with the data from Central Europe. We further analysed major compositional gradients within Bulgarian wet grasslands and changes in species richness along them. We sampled 164 wet grassland vegetation plots throughout Bulgaria. We further prepared a restricted data set of wet grasslands from Central-European phytosociological databases. Both data sets were merged and classified by modified TWINSPAN. Four distinct vegetation types were differentiated. Even if they correspond with traditional alliances, which are primarily drawn as geographically defined units in Western and Central Europe (sub-Mediterranean Trifolion resupinati, sub-continental Deschampsion cespitosae and Molinion caeruleae and sub-oceanic Calthion palustris), they all occur in Bulgaria. When more precise classification was applied, two types of sub-Mediterranean wet grasslands and one high-altitude type of Calthion grasslands were detected solely in Bulgaria. DCA analysis showed that altitude is a dominant gradient controlling variation in Balkan wet grasslands. The second DCA axis was interpreted as the gradient of nutrient availability. Species richness shows skewed-unimodal trends along both major gradients, with the highest species richness in intermittently wet nutrient-limited grasslands. Tukey post-hoc test of altitudinal differences amongst vegetation types is significant for all pairs of clusters, suggesting that altitudinal differentiation is responsible for co-occurrence of nearly all European types of wet grasslands in Bulgaria. Our results suggest that (1) climate is an important factor for the diversity of wet grasslands; (2) Balkan vegetation of middle altitudes matches with that of Central Europe, whereas that of the lowest altitudes corresponds rather to the sub-Mediterranean region and high mountains are specific; (3) upward shift of Central-European vegetation types in southern Europe, so often described in forest vegetation is also evident for grassland vegetation and (4) the high diversity of Balkan vegetation is determined by a diverse relief enabling confluence of habitats possessing different climatic conditions.  相似文献   

19.
    
We present a simple method to detect pathogenicity islands and anomalous gene clusters in bacterial genomes. The method uses iterative discriminant analysis to define genomic regions that deviate most from the rest of the genome in three compositional criteria: G+C content, dinucleotide frequency and codon usage. Using this method, we identify many virulence-related gene islands, e.g. encoding protein secretion systems, adhesins, toxins, and other anomalous gene clusters, such as prophages. The program and the whole dataset, including the catalogs of genes in the detected anomalous segments, are publicly available at http://compbio.sibsnet.org/projects/pai-ida/. This program can be used in searching for virulence-related factors in newly sequenced bacterial genomes.  相似文献   

20.
Sample data from a number of sub-populations are often investigated in order to integrate the findings of different research studies on a particular area. In case of compositional samples, like the allele frequencies collected at a single locus in different surveys, the data are independent multinomial vectors. Each multinomial distribution depends on a specific probability vector, that is, the unknown relative composition of the sub-population. A Bayesian hierarchy approach is proposed here to model the variability of the sub-composition vectors around a common mean with possibly different scales. The common mean can be seen as the relative composition of the aggregated population. Scale parameters are well known in Biology as the Wright's inbreeding coefficients. The method presented here extends some previous work by assuming less prior knowledge on the subject and constraints on the model. A relatively simple Monte Carlo algorithm is described to perform joint inferences on general and local compositions and inbreeding coefficients. The method is applied on two case studies. The first one is based on DNA samples from ten Italian regions at the loci TH01 and FES, obtained from a database currently used for forensic identification, in which inbreeding assessments can be crucial. The second application is based on a set of colour-blind sample rates in North-East Indian populations collected by Choudhury (1994). The Author found some controversial results from the classical test for comparing proportions. A clearer picture, instead, is obtained by the current Bayesian approach.  相似文献   

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