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21.
The objective of this study was to explore whether the C and N content can be used to estimate the fat content of animal carcasses. Considering the mean C and N contents of body fat and body protein, the fat content (EE) [%] can be predicted from C and N values [%] according to the generally valid equation EE=1.3038·C – 4.237·N. The application of this equation to estimate the total fat content of all animal carcasses results in significant differences in fat content between predicted and measured values. Therefore, we derived specific equations for rats, pigs, cattle, sheep, broilers and mice to predict the fat content by dual linear regression analysis (y=EE [% DM], x1=C [% DM], x2=N [% DM]) based on measured fat, C, and N contents of animal body samples. The specific equations for different animals showed residual standard deviations of 1.55, 1.63, 1.12, 1.35, 1.85 and 0.92% fat for rats, pigs, cattle, sheep, broilers and mice, respectively.  相似文献   
22.
1. Agricultural intensification has caused dramatic biodiversity loss in many agricultural landscapes over the last century. Here, we investigated whether new types of farm ponds (made of artificial substrata) in intensive systems and natural‐substratum ponds in traditional farming systems differ in their value for aquatic biodiversity conservation. 2. We analysed the main patterns of environmental variation, compared α‐, β‐ and γ‐diversity of macroinvertebrates between ponds types and evaluated the role of submerged aquatic vegetation (SAV). Generalised additive models (GAM) were used to analyse the relationships of α‐ and β‐diversity with environmental predictors, and variation partitioning to separate the effect of environmental and spatial characteristics on the variation in macroinvertebrate assemblages. Moran’s eigenvector maps (MEMs) were used to define spatial variables. 3. A principal coordinate analysis (PCoA) detected a primary environmental gradient that separated nutrient‐rich ponds from those dominated by SAV; a secondary morphometric gradient distinguished natural‐substratum ponds, with large surface area and structural complexity, from artificial‐substratum ponds with steeper slopes. Natural‐substratum ponds had almost twice the α‐ and γ‐diversity of artificial‐substratum ponds, and diversity significantly increased when SAV was present, particularly in artificial‐substratum ponds. Total phosphorus (TP) strongly contributed to explain the patterns in diversity, while SAV was a significant predictor of assemblage composition and diversity. GAMs revealed optima of both α‐diversity at intermediate SAV covers and β‐diversity at intermediate–high TP concentrations. 4. These findings have important implications for conservation planning. Adaptation of artificial‐substratum ponds by adding natural substratum and smoothing the gradient of pond margins would improve their conservation value. Development of SAV with occasional harvests and certain cautionary measures to control nutrient levels may also improve both the agronomical and environmental function of ponds.  相似文献   
23.
A G protein-coupled natriuretic peptide-guanylyl cyclase receptor-B (NPR-B) located in plasma membranes from bovine tracheal smooth muscle shows complex kinetics and regulation. NPR-B was activated by natriuretic peptides (CNP-53 > ANP-28) at the ligand extracellular domain, stimulated by Gq-protein activators, such as mastoparan, and inhibited by Gi-sensitive chloride, interacting at the juxtamembrane domain. The kinase homology domain was evaluated by the ATP inhibition of Mn2+-activated NPR-B, which was partially reversed by mastoparan. The catalytic domain was studied by kinetics of Mn2+/Mg2+ and GTP, and the catalytic effect with GTP analogues with modifications of the /γ phosphates and ribose moieties. Most NPR-B biochemical properties remained after detergent solubilization but the mastoparan activation and chloride inhibition of NPR-B disappeared. Our results indicate that NPR-B is a highly regulated nano-machinery with domains acting at cross-talk points with other signal transducing cascades initiated by G protein-coupled receptors and affected by intracellular ligands such as chloride, Mn2+, Mg2+, ATP, and GTP.  相似文献   
24.
25.
A novel universal neuropeptide display approach in the mass range of 300-5000 Da was developed to complement two-dimensional gel electrophoresis in the analysis of peptides and small proteins from brain tissue samples. For the analysis of neuropeptides we utilized on-line nanoscale capillary reversed phase liquid chromatography and electrospray ionization quadrupole-time of flight mass spectrometry. The method was employed for the analysis of a large number of peptides from three specific rat brain regions. Approximately 1500 peptides from each brain region were detected in the same analysis. Several of these peptides were sequenced using collision-induced dissociation and identified by database search tools. In addition, a method for comparing peptide elution profiles between samples was developed, to provide two- and three-dimensional computer graphics of the profiles and to pinpoint differences for statistical measurements. Among the characterized peptides were fragments from proteins such as hemoglobin, alpha-synuclein, stathmin, cyclophilin, actin, NADH dehydrogenase, cytochrome c oxidase and prosomatostatin, as well as the bioactive neuropeptides W-hemorphin-4, and LW-hemorphin-7. The present study showed that the combination of nanoscale reversed phase liquid chromatography and high-resolution tandem mass spectrometry provides a novel and powerful approach to investigate a large number of peptides and protein fragments in the brain.  相似文献   
26.
The genetic diversity of Agave plants is threatened by clonal commercial reproduction and climatic change. Sexual reproduction is uncommon and research on seed germination is scarce. The present study evaluated the seed germination of Agave lechuguilla, Agave striata, Agave americana var. marginata, Agave asperrima, Agave cupreata, Agave duranguesis, Agave angustifolia ssp. tequilana and Agave salmiana at constant temperatures (10, 15, 20, 25, 30, 35 and 40°C). Initial imbibition (after the first 12 h) was significantly variable among species, positively correlated with seed weight (r = 0.6560, P < 0.001) and increased with temperature (from 35% at 10°C to 66% at 40°C). Temperature affected maximum imbibition (83–150%) for A. asperrima, A. lechuguilla, A. salmiana and A. striata; other species averaged 110%. Most germination kinetics best fitted a logistic model, whereas only a few treatments fit a Weibull model. The time to germination onset diminished (P < 0.05) from 125–173 h at 15°C to 68–84 h at 25°C, and then ascended to 84–196 h at 35°C. The mean germination rate and seed germination percentage after 312 h peaked at 25°C (0.50–0.95% seeds/h and 85–99%, respectively) and fell (P < 0.05) to near zero at 10 and 40°C. Temperatures of 10, 35 and 40°C were partially lethal to A. asperrima, A. duranguensis and A. salmiana seeds. The time to germination onset, seed germination percentage after 312 h and mean germination rate are best described by a Gaussian distribution, with its optimum at approximately 25°C. Thus, optimum temperatures are related to the ecological characteristics of each species area.  相似文献   
27.
The monophyletic family Zhangsolvidae comprises stout‐bodied brachyceran flies with a long proboscis and occurring only in the Cretaceous, originally known in shale from the Early Cretaceous Laiyang Formation (Fm.) in China (Zhangsolva Nagatomi & Yang), subsequently from limestones of the Early Cretaceous Crato Fm. of Brazil. Cratomyoides Wilkommen is synonymized with Cratomyia Mazzarolo & Amorim, both from the Crato Fm.; Cratomyiidae is synonymized with Zhangsolvidae. Two genera and three species of Zhangsolvidae are described: Buccinatormyia magnifica Arillo, Peñalver & Pérez‐de la Fuente, gen. et sp.n. and B. soplaensis Arillo, Peñalver & Pérez‐de la Fuente, sp.n. , in Albian amber from Las Peñosas Fm. in Spain; and Linguatormyia teletacta Grimaldi, gen. et sp.n. , in Upper Albian–Lower Cenomanian amber from Hukawng Valley in Myanmar. Buccinatormyia soplaensis and Linguatormyia teletacta are unique among all Brachycera, extant or extinct, by their remarkably long, flagellate antennae, about 1.6× the body length in the latter species. A phylogenetic analysis of 52 morphological characters for 35 taxa is presented, 11 taxa being Cretaceous species, which supports placement of the family within Stratiomyomorpha, although not to any particular family within the infraorder. This published work has been registered in Zoobank, http://zoobank.org/urn:lsid:zoobank.org:pub:F32CF887‐7C37‐45D5‐BD6B‐135FE9B729A7 .  相似文献   
28.
Polar solvents induce terminal differentiation in the human promyelocytic leukemia cell line HL-60. The present studies describe the functional changes that accompany the morphologic progression from promyelocytes to bands and poly-morphonuclear leukocytes (PMN) over 9 d of culture in 1.3 percent dimethylsulfoxide (DMSO). As the HL-60 cells mature, the rate of O(2-) production increase 18-fold, with a progressive shortening of the lag time required for activation. Hexosemonophosphate shunt activity rises concomitantly. Ingestin of paraffin oil droplets opsonized with complement or Ig increases 10-fold over 9 d in DMSO. Latex ingestion per cell by each morphologic type does not change significantly, but total latex ingestion by groups of cells increases with the rise in the proportion of mature cells with greater ingestion capacities. Degranulation, as measured by release of β-glucuronidase, lysozyme, and peroxidase, reaches maximum after 3-6 d in DMSO, then declines. HL-60 cells contain no detectable lactoferrin, suggesting that their secondary granules are absent or defective. However, they kill staphylococci by day 6 in DMSO. Morphologically immature cells (days 1-3 in DMSO) are capable of O(2-) generation, hexosemonophosphate shunt activity, ingestion, degranulation, and bacterial killing. Maximal performance of each function by cells incubated in DMSO for longer periods of time is 50-100 percent that of normal PMN. DMSO- induced differentiation of HL-60 cells is a promising model for myeloid development.  相似文献   
29.
Euptychiina is the most species‐rich subtribe of Neotropical Satyrinae, with over 450 known species in 47 genera (14 monotypic). Here, we use morphological characters to examine the phylogenetic relationships within Euptychiina. Taxonomic sampling included 105 species representing the majority of the genera, as well as five outgroups. A total of 103 characters were obtained: 45 from wing pattern, 48 from genitalia and 10 from wing venation. The data matrix was analysed using maximum parsimony under both equal and extended implied weights. Euptychiina was recovered as monophyletic with ten monophyletic genera, contrasting previous DNA sequence‐based phylogenies that did not recover the monophyly of the group. In agreement with sequence‐based hypotheses, however, three main clades were recognized: the ‘Megisto clade’ with six monophyletic and three polyphyletic genera, the ‘Taygetis clade’ with nine genera of which three were monophyletic, and the ‘Pareuptyhia clade’ with four monophyletic and two polyphyletic genera. This is the first morphology‐based phylogenetic hypothesis for Euptychiina and the results will be used to complement molecular data in a combined analysis and to provide critical synapomorphies for clades and genera in this taxonomically confused group.  相似文献   
30.
During a two-year study of a developmental surveillance programme covering all children under 5 in a large general practice in the south of England, 2157 children were examined, including 382 newborn babies seen at home. Suspected disorders--excluding those found during non-routine consultations--were discovered in 232 children (15% of boys and 11% of girls), of whom 171 (104 boys and 67 girls) were referred to specialist agencies. The number and nature of the disorders show that routine surveillance on the lines proposed by the Court Committee is worth while. Nevertheless, such programmes could not be started on a national scale without increased resources for the specialist services to which more children would need to be referred.  相似文献   
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