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1.
The authors evaluated the significance of individual properties (extroversion and individual anxiety) in the analysis of cardiorhythmograms. The subjects demonstrated significant correlations between the spectral characteristics of cardiac rhythm and extroversion and individual anxiety levels. The correlation between the spectral characteristics of the cardiac rhythm and extroversion significantly strengthened when the individual anxiety level was taken into account and vice versa. Cardiorhythmograms differed significantly in extroverts and introverts with increased and normal levels of individual anxiety.  相似文献   

2.
A contextual analysis combined with path analysis was applied to detect ecotype-specific past selection in hierarchically structured populations of wild barley, Hordeum spontaneum . In our analysis a multiple regression model incorporated several individual and ecotype-level unmeasured (derived) traits obtained by factor analysis from 20 measured morphological and phenological traits. Under favourable conditions (high water and nutrients) both individual and ecotype plant size (RF1) were significant predictors of individual plant fitness, estimated by either reproductive biomass or yield. Both individual and ecotype size of reproductive structures (RF2) were significantly related to individual reproductive biomass. Individual yield, however, significantly correlated with ecotype RF2 only. Transition to reproduction (RF3) correlated with neither reproductive biomass nor yield at individual level, but correlated with two estimates of fitness at ecotype level. In all cases, selection at the individual and ecotype levels was in opposition. We interpret the observed effect of ecotype identity on individual fitness not as a current group selection, but as a constraining effect of ecotype-specific past selection. The four ecotypes went through an environmentally specific selection process in their own environments with the optimal strategy evolved. Consequently, this strategy may have a constraining effect on plant performance in other environments. Under conditions of either low water or low nutrients the ecotype level did not contribute to individual fitness. The latter may suggest that a mechanism for plant responses to stress is largely independent of plant origin, with a difference between ecotypes under stressful conditions due entirely to the difference in amount, not architecture, of plasticity. © 2002 The Linnean Society of London, Biological Journal of the Linnean Society , 2002, 75 , 313–318.  相似文献   

3.
Unbiased estimation of individual asymmetry   总被引:1,自引:0,他引:1  
The importance of measurement error (ME) for the estimation of population level fluctuating asymmetry (FA) has long been recognized. At the individual level, however, this aspect has been studied in less detail. Recently, it has been shown that the random slopes of a mixed regression model can estimate individual asymmetry levels that are unbiased with respect to ME. Yet, recent studies have shown that such estimates may fail to reflect heterogeneity in these effects. In this note I show that this is not the case for the estimation of individual asymmetry. The random slopes adequately reflect between‐individual heterogeneity in the underlying developmental instability. Increased levels of ME resulted in, on average, lower estimates of individual asymmetry relative to the traditional unsigned asymmetry. This well‐known shrinkage effect in Bayesian analysis adequately corrected for ME and heterogeneity in ME resulting in unbiased estimates of individual asymmetry that were more closely correlated with the true underlying asymmetry.  相似文献   

4.
The individual positional isomers from the mono-PEGylated recombinant human granulocyte colony-stimulating factor (rhG-CSF) were successfully isolated with additional strong cation exchange chromatography using Source 15S. The three isolated individual positional isomers were found to be homogeneous by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), analytical size exclusion high-performance liquid chromatography (SE-HPLC), and analytical cation exchange HPLC (CIE-HPLC) and were also characterized with respect to site of PEGylation by enzymatic digestion with endoproteinase Lys-C and N-terminal sequencing. In addition, in vitro biological activity was determined by cell proliferation assay. It was determined that the three isolated individual positional isomers were PEGylated at Lys35, Met(N-terminal), and Lys17 of the rhG-CSF molecule with a 23-kDa trimer-structured methoxy polyethylene glycol N-hydroxysuccinimidyl functional group (mPEG-NHS). All individual positional isomers (Lys35-PEGylated rhG-CSF, Met(N-terminal)-PEGylated rhG-CSF, and Lys17-PEGylated rhG-CSF) retained in vitro biological activity and were found to be 18.5%, 37.6%, and 7.1%, respectively, compared with the rhG-CSF molecule. The significantly different in vitro biological activities observed in the individual positional isomers could be presumably due to interference of receptor binding or active sites on the rhG-CSF molecule. In conclusion, the individual positional isomers isolated from the mono-PEGylated rhG-CSF were well characterized with respect to the site of PEGylation involving Lys35, Met(N-terminal), and Lys17. This characterization of the individual positional isomers would be critical to provide a basis for establishing consistency in the manufacturing process.  相似文献   

5.
本研究在江西永丰、浙江开化和安徽滁州3个试验点,以32个种源的麻栎试验林为对象,分析了不同种源间林木生长变异、主要经济性状(地上单株生物量)随林龄的动态变化,并基于AMMI模型进行生长性状稳定性分析和优良种源选择。结果表明: 3个试验点麻栎不同种源间的树高、胸(地)径和地上单株生物量均具有显著差异。麻栎地上单株生物量受地点、种源、种源×地点交互作用的显著影响,其中地点对生长变异影响最大,其次为种源和种源×地点。不同地点麻栎苗期(1~3年生)和幼林期(4~11年生)优良种源的选择结果具有较大差异。根据第11年地上单株生物量分别筛选了在当地表现较好的种源,江西永丰试验点7个优良种源,高出试验点均值15.6%~57.8%;浙江开化试验点7个优良种源,高出试验点均值19.2%~45.2%;安徽滁州试验点8个优良种源,高出试验点均值24.9%~63.3%。综合生长量和稳定性表现,筛选出4个适于3个地理区域短轮伐期炭用林培育的优良种源,这些种源地上单株生物量均值为36.55 kg,稳定性参数均值为0.97。  相似文献   

6.
The objective of this study was to estimate the carbon storage capacity of Pinus densiflora stands using remotely sensed data by combining digital aerial photography with light detection and ranging (LiDAR) data. A digital canopy model (DCM), generated from the LiDAR data, was combined with aerial photography for segmenting crowns of individual trees. To eliminate errors in over and under-segmentation, the combined image was smoothed using a Gaussian filtering method. The processed image was then segmented into individual trees using a marker-controlled watershed segmentation method. After measuring the crown area from the segmented individual trees, the individual tree diameter at breast height (DBH) was estimated using a regression function developed from the relationship observed between the field-measured DBH and crown area. The above ground biomass of individual trees could be calculated by an image-derived DBH using a regression function developed by the Korea Forest Research Institute. The carbon storage, based on individual trees, was estimated by simple multiplication using the carbon conversion index (0.5), as suggested in guidelines from the Intergovernmental Panel on Climate Change. The mean carbon storage per individual tree was estimated and then compared with the field-measured value. This study suggested that the biomass and carbon storage in a large forest area can be effectively estimated using aerial photographs and LiDAR data.  相似文献   

7.
Cartilage contact geometry, along with joint loading, can play an important role in determining local articular cartilage tissue stress. Thus individual variations in cartilage thickness can be associated with both individual variations in joint loading associated with activities of daily living as well as individual differences in the anatomy of the contacting surfaces of the joint. The purpose of this study was to isolate the relationship between cartilage thickness predicted by individual variations in contact surface geometry based on the radii of the femur and tibia vs. cartilage thickness predicted by individual variations in joint loading. Knee magnetic resonance (MR) images and the peak knee adduction moments during walking were obtained from 11 young healthy male subjects (age 30.5+/-5.1 years). The cartilage thicknesses and surface radii of the femoral and tibial cartilage were measured in the weight-bearing regions of the medial and lateral compartments of three-dimensional models from the MR images. The ratio of contact pressure between the medial and lateral compartments was calculated from the radii of tibiofemoral contact surface geometries. The results showed that the medial to lateral pressure ratios were not correlated with the medial to lateral cartilage thickness ratios. However, in general, pressure was higher in the lateral than medial compartments and cartilage was thicker in the lateral than medial compartments. The peak knee adduction moment showed a significant positive linear correlation with medial to lateral thickness ratio in both femur (R(2)=0.43,P<0.01) and tibia (R(2)=0.32,P<0.01). The results of this study suggest that the dynamics of walking is an important factor to describe individual differences in cartilage thickness for normal subjects.  相似文献   

8.
The main objective of present correlational investigation was to clarify relationships between nonverbal creativity indices and individual electroencephalogram alpha activity indices: individual alpha peak frequency, alpha band width, magnitude of alpha desynchronization and alpha spindle indices such as duration, amplitude, variability and skewness. The EEG was recorded in 98 healthy male right-handed subjects. Scores of nonverbal creativity (i. e., fluency, originality, and flexibility) were assessed using the Torrance test of nonverbal performance. The study showed that fluency in creative performance was associated with individual alpha peak frequency and alpha spindles duration, whereas originality and plasticity--with individual alpha band width and spindle amplitude variability. The findings also show that both highest and lowest individual alpha peak frequency indices are associated with enhanced scores of originality. It is suggested that individual alpha activity indices could be presented as individual predictors of fluency, plasticity and originality of nonverbal creativity.  相似文献   

9.
氮磷亏缺对玉米根系水流导度的影响   总被引:12,自引:0,他引:12  
在人工气候室水培条件下,从单根和整株根系两个层次研究了N、P营养与玉米(Zea mays L.)根系水流导度(root hydraulic conductivity,Lpr)间的关系。结果表明:表型抗旱的杂交种F1代户单4号和母本天四的单根水导和整株根系水导均高于不抗旱的父本478,其中天四的单根水导最高,而户单4号的整株根系水导最高。N、P亏缺均使玉米单根水导和整株根系水导降低,但与N亏块相比,P亏缺的植株具有较高的整株根系水导和较低的单根水导。整株根系的水导更能反映植物根系的输水性能。  相似文献   

10.
To confirm the availability of individual dose evaluation for the return of residents after the accident at the Fukushima Dai-ichi Nuclear Power Plant (FNPP), we evaluated individual doses of radiation as measured by personal dosimeters in residents who temporarily stayed in Evacuation Order Areas in Kawauchi village, which is partially located within a 20 km radius of the FNPP. We also compared individual doses with the external radiation doses estimated from the ambient dose rates and with doses estimated from the concentrations of radionuclides in the soil around each individual’s house. Individual doses were significantly correlated with the ambient doses in front of the entrances to the houses (r = 0.90, p<0.01), in the backyards (r = 0.41, p<0.01) and in the nearby fields (r = 0.80, p<0.01). The maximum cumulative ambient doses in the backyards and fields around the houses were 6.38 and 9.27 mSv/y, respectively. The maximum cumulative individual dose was 3.28 mSv/y, and the median and minimum doses were 1.35 and 0.71 mSv/y. The estimated external effective doses from concentrations of artificial radionuclides in soil samples ranged from 0.03 to 23.42 mSv/y. The individual doses were moderately correlated with external effective doses in the backyards (r = 0.38, p<0.01) and in the fields (r = 0.36, p<0.01); however, the individual doses were not significantly correlated with the external effective doses in front of the entrances (r = 0.01, p = 0.92). Our study confirmed that individual doses are low levels even in the evacuation order area in Kawauchi village, and external effective dose levels are certainly decreasing due to the decay of artificial radionuclides and the decontamination of contaminated soil. Long-term follow-up of individual doses as well as internal-exposure doses, environmental monitoring and reconstruction of infrastructure are needed so that residents may return to their hometowns after a nuclear disaster.  相似文献   

11.
In a release experiment with cod in Norway, the apparent mean growth rates of 3+ cod, calculated by sampling the released cohorts at different ages, were very slow (<0·08 mm day−1). However, when individual growth rates of individual tagged cod of the same size range were measured, the mean growth rates were much faster (0·24 mm day−1). These observations were attributed to size-selective fishing mortality and were illustrated by an individual based simulation model of a cohort of cod with variable individual growth rates. The effects on mean length at age of the surviving cohort of increasing fishing intensity were demonstrated. The model showed that size-selective fishing with the observed individual growth variation, removed the fastest-growing individuals at proportionally higher rates than the slower-growing ones, leading to decreased apparent mean growth rate. The fishing pattern which gave the optimum yield, changed when individual variation was included, and when the apparent growth rate was used in the model the yield per recruit reduced dramatically. This study has shown that individual growth heterogeneity and size-selective mortality are factors which should be considered in future fisheries management models.  相似文献   

12.
Potato plants ( Solanum tuberosum L. ev. Ostara) were grown in water culture and the growth rate of individual tubers was measured daily or at two day intervals. Tubers of different growth rate and/or different age (days after tuberization) were harvested and analysed for indolylacetic acid (IAA) and abscisic acid (ABA). Within individual tubers the IAA content decreases from the apical to the basal part of the tuber. Tuber age and corresponding fresh weight are negatively correlated with the endogenous IAA content. If, however, individual tubers of comparable age but different growth rates are compared, a significant positive correlation between growth rate and IAA content is revealed, while ABA showed a significant negative correlation with growth rate. Removal of all fast-growing tubers from individual plants causes an increase in the growth rate of the remaining tubers within 3–4 days. This coincides with a particularly steep increase in IAA content. The data support the idea that endogenous IAA content may be one factor responsible for controlling the growth rate ("sink-activity ") of individual tubers.  相似文献   

13.
The growth dynamics of shoot populations of Polygonum cuspidatumwere investigated at the Houei crater (approx. 2380 m abovesea level) on the south-eastern slope of Mount Fuji. At thisstudy site, a genetic individual of this species produces apopulation of shoots in the form of a patch occupying a certainground area. Generally, genetic individuals are located awayfrom each other and hence there is little interaction betweenindividuals. A large-sized individual occupying 31·2m2 ground area with shoots, a medium-sized individual (5·6m2) and a small-sized individual (1·4 m2) were selectedfor this study. In each individual, growth was investigatedat the shoot level. The results were analysed based on the diffusionmodel. Early in the growing season in 1990, there was littledifference in LAI (leaf area index) and shoot density betweenthe individuals. Shoots of the small- and medium-sized individualsshowed size-independent height growth, whilst those of the larger-sizedindividual showed size-dependent height growth. Consequently,small-sized shoots of the small- and the medium-sized individualshad greater RGRs of shoot height growth than those of the largeindividual at the early stage. As a result, in the small- andmedium-sized individuals, cv (coefficient of variance) and skewnessof shoot height decreased with time. Increases in cv and skewnessof shoot height were found in the large-sized individual. Thesize-independent growth pattern of shoot height in the small-and medium-sized individuals during early growing stages isdifferent from the growth pattern of non-clonal plant species,in which plant height growth is positively size-dependent. Theexistence of a regulatory mechanism of shoot height growth issuggested for the small- and medium-sized individuals. The foliagestructure of the large-sized individual was different from thatof the medium- and small-sized individuals. The foliage structureof small- and medium-sized individuals was similar to the theoretical"optimal foliage structure" of plants. In clonal plant species,a genetic individual occupies a certain ground area with itsshoots. Therefore, "optimal foliage structure" per unit groundarea brings about maximization of photosynthetic rate for agenetic individual, which is consistent with the maximizationof fitness at the level of the individual plant.Copyright 1994,1999 Academic Press Clonal plant species, diffusion model, growth regulatory mechanism, genetic individual, maximization of fitness  相似文献   

14.
Humans strongly depend on individual and social learning, both of which are highly effective and accurate. I study the effects of environmental change on the evolution of the effectiveness and accuracy of individual and social learning (individual and social learning levels) and the number of pieces of information learned individually and socially (individual and social learning capacities) by analyzing a mathematical model. I show that individual learning capacity decreases and social learning capacity increases when the environment becomes more stable; both decrease when the environment becomes milder. I also show that individual learning capacity increases when individual learning level increases or social learning level decreases, while social learning capacity increases when individual or social learning level increases. The evolution of high learning levels can be triggered when the environment becomes severe, but a high social learning level can evolve only when a high individual learning level can simultaneously evolve with it.  相似文献   

15.
The alkylating derivatives of four individual diastereomers of the oligonucleotide [dTp(Et)]3dTpU and two individual diastereomers of oligonucleotide [dTp(Et)dTp]4 have been synthesized. The reagents with the phosphorus atoms in the enantiomeric p" configuration are shown to be more efficient in reacting with poly(dA) and with nucleic acids in Krebs-2 ascites carcinoma cells compared to those with the phosphorus atoms in the p' configuration.  相似文献   

16.
B N Kholodenko 《Biofizika》1980,25(2):258-264
The problem is considered concerning the effect of individual differences of erythrocyte energetic metabolism parameters in the regulation (stablization) of ATP level. It has been found that equal quality of stabilization of relative ATP concentration (ATP/(AMP+ADP+ATP)) in erythrocytes with very different individual parameters is provided, firstly, by presence of scaling invariance of the characteristics of ATP-producing and ATP-consuming systems, and, secondly, by coincidence between the physiological values of ATP/(AMP+ADP+ATP) ratio for all the individuals. Scaling invariance property results in the essential reduction of the effective dimension of the individual parameters space. Revealed is a single parameter (function of all individual parameters), which defines the level of relative ATP concentration or the erythrocyte energy charge. The hypothesis is formulated that erythrocyte has two levels of energetic metabolism regulation, of which the first level is responsible for regulation of relative ATP concentration (due to the self-energy system functioning), while the second one provides (for a long time) regulation of the individual parameter values.  相似文献   

17.
城市树木的固碳能力是决定城市绿地碳汇大小的重要因素。为探究上海常见树种单株固碳能力的差异及影响因子,使用174个城市森林固定样地的长期观测数据,估算了香樟、水杉、银杏和雪松四个树种的单株固碳能力(即年固碳量),采用多元线性回归模型分析了各树种单株固碳能力与个体大小、植株密度和城市环境因子(温度、降水量和夜间灯光强度)的关系。结果表明:(1)香樟、水杉、银杏和雪松的单株固碳能力分别介于4.01-51.58 kg/a、1.04-13.47 kg/a、0.62-18.56 kg/a和1.48-8.47 kg/a之间,在各径组中香樟的固碳能力均显著高于其他树种。(2)个体大小是决定单株固碳能力的最主要因子,个体越大(胸径0-50 cm范围内)单株固碳能力越大;植株密度越大,香樟和水杉的单株固碳能力越小,银杏的单株固碳能力越大。(3)城市环境因子中,温度对树木单株固碳能力有显著负向影响,而降水量和夜间灯光强度对树木单株固碳能力的影响因树种而异。其中香樟和水杉分别与降水量呈显著负相关和正相关关系,但均与夜间灯光强度呈显著正相关关系。在上海未来城市森林建设和管理中,应根据不同树种单株固碳能力的差异及其对不同环境因子的敏感性,适地适树绿化造林,提升城市森林的固碳效益。  相似文献   

18.
The cybernetic definition of a living individual proposed previously (Korzeniewski, 2001) is very abstract and therefore describes the essence of life in a very formal and general way. In the present article this definition is reformulated in order to determine clearly the relation between life in general and a living individual in particular, and it is further explained and defended. Next, the cybernetic definition of a living individual is confronted with the real world. It is demonstrated that numerous restrictions imposed on the cybernetic definition of life by physical reality imply a number of particular properties of life that characterize present life on Earth, namely: (1) a living individual must be a dissipative structure (and therefore a low-entropy thermodynamic system out of the state of equilibrium); (2) spontaneously-originated life must be based on organic compounds; (3) evolutionarily stable self-dependent, free-living individuals must have some minimal level of complexity of structure and function; (4) a living individual must have a record of identity separated from an executive machinery; (5) the identity of living individuals must mutate and may evolve; (6) living individuals may collect and accumulate information in subsequent generations over very long periods of time; (7) the degree of complexity of a living individual reflects the degree of complexity of its environment (ecological niche) and (8) living individuals are capable of supple adaptation to varying environmental conditions. Thus, the cybernetic definition of a living individual, when confronted with the real physical world, generates most of the general properties of the present life on Earth.  相似文献   

19.
The time lag of the QT interval adaptation to heart rate changes (QT/RR hysteresis) was studied in 40 healthy subjects (18 females; mean age, 30.4+/-8.1 yr) with 3 separate daytime (>13 h) 12-lead electrocardiograms (ECG) in each subject. In each recording, 330 individual 10-s ECG segments were measured, including 100 segments preceded by 2 min of heart rate varying greater than +/-2 beats/min. Other segments were preceded by a stable heart rate. In segments preceded by variable rate, QT/RR hysteresis was characterized by lambda parameters of the exponential decay models. The intrasubject SDs of lambda values were compared with the intersubject SD of the individual means. The lambda values were also correlated to individually optimized parameters of heart rate correction. Intrasubject SDs of lambda were substantially smaller than the population SD of individual means (0.390+/-0.197 vs. 0.711, P<0.0001). The lambda values were unrelated to the QT/RR correction parameters. When compared with the corrected QT (QTc) for averaged RR intervals in 10-s ECGs and with the averaged RR intervals in 2-min history, QTc for QT/RR hysteresis led to a substantially smaller SD of QTc values (11.4+/-2.00, 6.33+/-1.31, and 4.66+/-0.85 ms, respectively, P<0.0001). Thus the speed with which the QT interval adapts to heart rate changes is highly individual with intrasubject stability and intersubject variability. QT/RR hysteresis is independent of the static QT/RR relationship and should be considered as a separate physiological process. The combination of individual heart rate correction with individual hysteresis correction of the QT interval is likely to lead to substantial improvements of cardiac repolarization studies.  相似文献   

20.
Tao Y  Zhang L 《Biopolymers》2006,83(4):414-423
The chemical structure of a water-soluble polysaccharide, coded as TM3b, extracted from sclerotia of Pleurotus tuber-rigium was analyzed to be a hyperbranched beta-D-glucan with beta-(1-->6), beta-(1-->4), and beta-(1-->3)-linked residues, with degree of branching (DB) of 57.6%. The results from size-exclusion chromatography combined with laser light scattering (SEC-LLS) revealed that the hyperbranched polysaccharide easily aggregated in 0.15 M aqueous NaCl, whereas it dispersed as individual chains in DMSO. The weight-average molecular weight (M(w)), radius of gyration, intrinsic viscosity, and chain density of TM3b in DMSO and in 0.15 M aqueous NaCl were measured with SEC-LLS, LLS, and viscometry. The results indicated that single chains and aggregates with aggregation number of 12 coexisted in the aqueous solution, whereas individual molecules of TM3b occurred in DMSO. In view of the molecular parameters, the aggregates in aqueous solution exhibited more compact chain structure than the individual molecules in DMSO. Furthermore, transmission electron microscopy and atomic force microscopy showed that all of the aggregates and individual molecules exhibited spherical particles in the solutions. This work provided the valuable information of chain conformation and molecular morphology of the hyperbranched polysaccharide in different solvents.  相似文献   

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