Does gantry rotation time influence accuracy of volume computed tomography dose index (CTDIvol) in modern CT?

PurposeThe purpose of this study was to develop a gantry overrun corrected CTDI_vol (cCTDI_vol) dosimetry and evaluate the differences between the displayed CTDI_vol (dCTDI_vol), measured CTDI_vol (mCTDI_vol), and the cCTDI_vol.Methods and materialsThe each 8 rotation times between 275 and 1000 ms of two CT scanners were investigated. Rotation time (T_rot) and the beam-on time (T_beam) in axial scanning were measured accurately to determine the gantry overrun time (T_over) as T_beam − T_rot. Subsequently, mCTDI_vol was measured by using a 100 mm ionization chamber and CTDI phantoms. Furthermore, we introduced a gantry overrun correction factor (C_o = T_rot/T_beam) to obtain cCTDI_vol. Upon completion of the data acquisition, the dCTDI_vol and mCTDI_vol were compared with the cCTDI_vol.ResultsThe discrepancies of T_rot were 0.2 ± 0.2 ms as compared to the preset rotation times, and T_over was machine-specific and almost constant (22.4 ± 0.5 ms or 45.1 ± 0.3 ms) irrespective of the preset rotation time. Both dCTDI_vol and mCTDI_vol were increasingly overestimated compared to cCTDI_vol as the faster the preset rotation time was selected (1.7–23.5%).ConclusionThe rotation time influences the accuracy of CTDI_vol in modern CT, and should be taken into consideration when assessing the radiation output in modern CT.     

Chronotype and time metaphors: morning-types conceive time as more friendly and less hostile

Recent studies have shown that diurnal preference (Morningness–Eveningness, also labeled chronotype) is an important predictor of temporal perspectives. In the present paper we draw upon these results in a study aiming to investigate differences between Morning-, Neither- and Evening-types in conceiving time. Based on data gathered from a sample of 316 university students, we analyzed associations between chronotype and dimensions of Time Metaphors Questionnaire. Morning preference was associated with a more positive, friendly view of time, whereas evening preference was related to conceiving time as negative and hostile. The above results were obtained using both dimensional and circadian typology approaches. The results are in line with a growing body of data indicating elevated negative emotionality of Evening-types. Possible mechanisms underpinning these associations are discussed in light of recent developments in the field of chronopsychology.     

The Analysis of the Geometric Structure of the Delayed Time Used in the Embedding Process in Predicting Chaotic Time Series

1IntroductionForaphysicssyStem,onemayonlyobtainapieceOfiofo~ionabbotitSd~edPaces.In~cases,oneorat~SeveralvariableSoftheSyStemismeaSUledasthesyStemevolvesinaclodoftime.ExamplesarethemeaSuredtetnperatUle,blabsP~ofahumanthey;concentrationsof~entsinachendcalreaction,componentsofthevelvetyOfthefluidincertaindirectionSandthefluctuationOfthePriceinasacmarket.AllthesemeasureddatapresentasatIme~esxl,xZ,'.,xj,inwhichthesuhiindexpreSentSthetimeSampledregUlarlybyatimenitedr.Thequestionhereishow…     

EEG Activity in the Process of Measuring-off of Time Intervals by Humans

We recorded EEG from sites C3 and C4 in an experimental situation with internal counting-off of a 20-sec-long time interval, whose beginning and end were limited by the tested subject by pushing a button; 65 adult men and women took part in the tests. In the first experimental series, the subject obtained no real information on the accuracy in production of the interval. In the second series, such information was displayed by feedback visual signals. We calculated means of the measured intervals ( ), coefficient of variation of the realizations (CV), and, in the series with the real feedback, successfulness of measuring-off (normalized number of fits within an acceptable range of the standard interval, 19 to 21 sec). Analysis of the data obtained in the first experimental series for the entire tested group demonstrated the existence of a reverse dependence between the modal frequency of EEG beta rhythm recorded from the left hemisphere in the course of measuring-off of the interval and the value. In the second series, we found significant negative correlation between the beta rhythm power in both hemispheres and CV, that between the alpha rhythm power in the left hemisphere and , and positive correlation between the alpha rhythm frequency in the left hemisphere and successfulness of the interval counting-off. Analysis of the dynamics of EEG of each tested subject demonstrated the existence of mostly reverse dependences between the powers of a few EEG rhythms and duration of the produced interval. We hypothesize that the frequencies of the alpha and beta EEG oscillations play the role of significant indices reflecting the speed of the internal clock of the individual. We also emphasize the complex nature and the high individual variability of the EEG pattern in the course of measuring-off of time intervals.     

A three‐component system incorporating Ppd‐D1, copy number variation at Ppd‐B1, and numerous small‐effect quantitative trait loci facilitates adaptation of heading time in winter wheat cultivars of worldwide origin

The broad adaptability of heading time has contributed to the global success of wheat in a diverse array of climatic conditions. Here, we investigated the genetic architecture underlying heading time in a large panel of 1,110 winter wheat cultivars of worldwide origin. Genome‐wide association mapping, in combination with the analysis of major phenology loci, revealed a three‐component system that facilitates the adaptation of heading time in winter wheat. The photoperiod sensitivity locus Ppd‐D1 was found to account for almost half of the genotypic variance in this panel and can advance or delay heading by many days. In addition, copy number variation at Ppd‐B1 was the second most important source of variation in heading, explaining 8.3% of the genotypic variance. Results from association mapping and genomic prediction indicated that the remaining variation is attributed to numerous small‐effect quantitative trait loci that facilitate fine‐tuning of heading to the local climatic conditions. Collectively, our results underpin the importance of the two Ppd‐1 loci for the adaptation of heading time in winter wheat and illustrate how the three components have been exploited for wheat breeding globally.     

犀角地黄汤化裁方对蛇伤患者血浆TT、PT、APTT的影响

目的观察犀角地黄汤化裁方对血循毒或混合毒蛇咬伤出现血分证的患者血浆TT、PT、APTT的影响。方法选择血循毒或混合毒蛇咬伤2h内的患者130例,随机分为2组,均给予常规治疗,治疗组加服犀角地黄汤化裁方。于就诊时、咬伤后72h测定其血浆TT、PT、APTT,并进行比较。结果2组患者在初诊时(伤后2h内)血浆TT、PT、APTT无明显差异,均在正常范围内;伤后72h三项指标均升高,对照组显著高于治疗组(P<0.05)。结论犀角地黄汤化裁方能抑制血循毒或混合毒蛇咬伤患者血浆TT、PT、APTT的延长,对蛇伤引起的凝血障碍有防治作用。     

A sulfated fucan from the brown alga Laminaria cichorioides has mainly heparin cofactor II-dependent anticoagulant activity

The major acidic polysaccharide from the brown alga Laminaria cichorioides is a complex and heterogeneous sulfated fucan. Its preponderant structure is a 2,3-disulfated, 4-linked alpha-fucose unit. The purified polysaccharide has a potent anticoagulant activity, as estimated by APTT assay ( approximately 40 IU/mg), which is mainly mediated by thrombin inhibition by heparin cofactor II. It also accelerates thrombin and factor Xa inhibition by antithrombin but at a lower potency. Sulfated fucan from L. cichorioides is a promising anticoagulant polysaccharide and a possible alternative for an antithrombotic compound due to its preferential heparin cofactor II-dependent activity.     

Disorders of the Menstrual Cycle in Elite Female Ice Hockey Players and Figure Skaters

The purpose of this study was to assess and compare the incidence of delayed menarche and menstrual dysfunction among elite ice hockey players and figure skaters. Forty-three ice hockey players (23.5 ± 4.8 years, 68.2 ± 1.2 kg, 1.68 ± 0.01 m) and 39 figure skaters (17.5 ± 3.4 years, 53.7 ± 5.8 kg, 1.64 ± 0.05 m) completed a self-administered questionnaire on their menstrual status and history, training regimens and lifestyle. Age at menarche did not differ significantly between ice hockey players (13.3 ± 1.3 years) and figure skaters (13.7 ± 1.4 years). Menarche was unrelated to nationality, vigorous training premenarche or age at which the athlete began her sport, but was correlated with the age at menarche of the athletes’ mothers (r = 0.39, p &lt; 0.05). Hormonal contraceptives were used by 35% of ice hockey players and 15% of the figure skaters. Amenorrhea and oligomenorrhea were experienced by 7.1% and 38.7% of postmenarcheal, ice hockey players and figure skaters respectively not using hormonal contraceptives. Menstrual dysfunction was associated with both age and age at menarche in the ice hockey players only. Training factors, and psychological pressure were perceived by the athletes to contribute to menstrual dysfunction. A greater training volume, younger age at commencing sport, lower body mass, greater subjective body image pressure and younger biological and gynaecological age were reported among the figure skaters, and were proposed to explain the higher incidence of menstrual dysfunction among the figure skaters compared with the ice hockey players. Figure skaters appear at increased risk of amenorrhea and oligomenorrhea compared with ice hockey players, which may be linked to training and physical characteristics of the sports.     

Prospects for the biology of human intelligence

Despite the ubiquitous nature of Spearman's g in mental test performance, the charge «intelligence is what intelligence tests test» has not been countered in a satisfactory way. It is proposed that there are two ways to answer this complaint. The first concerns the new hypothesis testing models in factor analysis. The second involves studying the ‘biology of intelligence’. The biology of intelligence has various meanings and four are discussed: biology as theory; biology as race and genetics; biology as neurobiology; and biology as basic psychological processes. The last of these is considered in some detail and it is found that reaction time, evoked potentials and inspection time offer bright prospects for further research on the biology of psychometric intelligence.     

First Passage Time Analysis of Animal Movement and Insights into the Functional Response

Movement plays a role in structuring the interactions between individuals, their environment, and other species. Although movement models coupled with empirical data are widely used to study animal distribution, they have seldom been used to study search time. This paper proposes first passage time as a novel approach for understanding the effect of the landscape on animal movement and search time. In the context of animal movement, first passage time is the time taken for an animal to reach a specified site for the first time. We synthesize current first passage time theory and derive a general first passage time equation for animal movement. This equation is related to the Fokker–Planck equation, which is used to describe the distribution of animals in the landscape. We illustrate the first passage time method by analyzing the effect of territorial behavior on the time required for a red fox to locate prey throughout its home range. Using first passage time to compute search times, we consider the effect of two different searching modes on a functional response. We show that random searching leads to a Holling type III functional response. First passage time analysis provides a new tool for studying how animal movement may influence ecological processes.     

立止血对家兔止血效果的研究

目的 观察立止血对家兔的止血效果,为该药的临床应用及研究类似产品提供可借鉴的资料。方法 测定家兔静注立止血前、后的因时间和凝血时间值,经统计学分析。结果 静沪立止血后所测不同时估（测至２４ｈ）的出血时间、凝血时间均经注药前自身空白对照缩短,具阶段性。结论 初步证实立止血具有高效、速效、长效、安全的作用特性,同时揭示立止血的止血功能具阶段性的特点。     

Genome-wide insertion–deletion (InDel) marker discovery and genotyping for genomics-assisted breeding applications in chickpea

We developed 21,499 genome-wide insertion–deletion (InDel) markers (2- to 54-bp in silico fragment length polymorphism) by comparing the genomic sequences of four (desi, kabuli and wild C. reticulatum) chickpea [Cicer arietinum (L.)] accessions. InDel markers showing 2- to 6-bp fragment length polymorphism among accessions were abundant (76.8%) in the chickpea genome. The physically mapped 7,643 and 13,856 markers on eight chromosomes and unanchored scaffolds, respectively, were structurally and functionally annotated. The 4,506 coding (23% large-effect frameshift mutations) and regulatory InDel markers were identified from 3,228 genes (representing 11.7% of total 27,571 desi genes), suggesting their functional relevance for trait association/genetic mapping. High amplification (97%) and intra-specific polymorphic (60–83%) potential and wider genetic diversity (15–89%) were detected by genome-wide 6,254 InDel markers among desi, kabuli and wild accessions using even a simpler cost-effective agarose gel-based assay. This signifies added advantages of this user-friendly genetic marker system for manifold large-scale genotyping applications in laboratories with limited infrastructure and resources. Utilizing 6,254 InDel markers-based high-density (inter-marker distance: 0.212 cM) inter-specific genetic linkage map (ICC 4958 × ICC 17160) of chickpea as a reference, three major genomic regions harboring six flowering and maturity time robust QTLs (16.4–27.5% phenotypic variation explained, 8.1–11.5 logarithm of odds) were identified. Integration of genetic and physical maps at these target QTL intervals mapped on three chromosomes delineated five InDel markers-containing candidate genes tightly linked to the QTLs governing flowering and maturity time in chickpea. Taken together, our study demonstrated the practical utility of developing and high-throughput genotyping of such beneficial InDel markers at a genome-wide scale to expedite genomics-assisted breeding applications in chickpea.     

高原鼠兔ob基因的组织表达特征

ob基因编码的leptin蛋白在调节生物体能量平衡中起到重要作用。本研究应用Taqman探针real time PCR技术对高原鼠兔ob基因的组织分布进行检测。通过提取不同组织总RNA,经DNase I消化后,用随机引物进行反转录合成cDNA,采用特异性Taqman探针和引物分别对ob基因及β-actin基因进行实时定量PCR扩增,对不同组织中ob基因和β-actin基因的初始拷贝数之比进行比较。结果表明ob基因在脑、心脏、肺、肝脏、脾脏、肾脏、骨骼肌、脂肪组织中均有表达,其中以白色脂肪组织中ob基因表达量最高,其次为心脏和肺,表达量最低的是肝脏和肾脏。     

Residence time and exposure time of sinking phytoplankton in the euphotic layer

The residence time of a sinking particle in the euphotic layer is usually defined as the time taken by this particle to reach for the first time the bottom of the euphotic layer. According to this definition, the concept of residence time does not take into account the fact that many cells leaving the euphotic layer at some time can re-enter the euphotic layer at a later time. Therefore, the exposure time in the surface layer, i.e. the total time spent by the particles in the euphotic layer irrespective of their possible excursions outside the surface layer, is a more relevant concept to diagnose the effect of diffusion on the survival of phytoplankton cells sinking through the water column.While increasing the diffusion coefficient can induce both a decrease or an increase of the residence time, the exposure time in the euphotic layer increases monotonically with the diffusion coefficient, at least when the settling velocity does not increase with depth. Turbulence is therefore shown to increase the total time spent by phytoplankton cells in the euphotic layer.The generalization of the concept of exposure time to take into account the variations of the light intensity with depth or the functional response of phytoplankton cells to irradiance leads to the definition of the concepts of light exposure and effective light exposure. The former provides a measure of the total light energy received by the cells during their cycling through the water column while the latter diagnose the potential growth rate.The exposure time, the light exposure and the effective light exposure can all be computed as the solution of a differential problem that generalizes the adjoint approach introduced by Delhez et al. (2004) for the residence time. A general analytical solution of the 1D steady-state version of this equation is derived from which the properties of the different diagnostic tools can be obtained.     

Consequences of sexually dimorphic timing of emergence and flowering in Silene latifolia

1 Males and females of dioecious plant species often differ in a variety of secondary characteristics, such as size, flower number and flowering time, suggesting that dioecious species have sex-specific selection histories. However, a potential source of these dimorphic traits is age differences between males and females. By sowing 3000 seeds of the dioecious perennial, Silene latifolia (Caryophyllaceae), on a single day, we were able to assess the contribution of sex differences in emergence time to the development of sexually dimorphic adult traits.
2 Females emerged before males in our experimental field population, but on average males flowered first. Age differences between males and females did not therefore cause the earlier flowering of males.
3 The consequence of the detected differences in emergence and phenology between males and females was explored by path analysis. Emergence time had a strong direct effect on flower production as well as an indirect effect through flowering time. The regression coefficient of flowering time on emergence time was significantly larger for male plants.
4 A phenotypic selection analysis revealed that seedlings emerging early suffered greater mortality than those emerging later. Seedlings emerging early, however, developed into plants with more flowers, indicating that there was a trade-off between survivorship and reproductive performance. Seeds with intermediate emergence times had the highest total fitness, indicating the presence of stabilizing selection. Despite the strong mortality selection against early emergers, we detected no shift in the sex ratio compared with the sex ratio of seeds matured under low-mortality greenhouse conditions.     

丹参变应原基因（Sam a1）的克隆及其原核表达

Ⅰ型变态反应是小分子植物蛋白结合IgE抗体引起的一种疾病。本文首次从丹参中克隆出变应原蛋白基因,命名为：Sam a1（GenBank注册号：EU122383）。Sam a1包含483 bp的开放读码框,编码160个氨基酸残基。其推导氨基酸（命名为：Sam a1）具有Bet v1结构域,属于病原菌相关的Bet v1蛋白家族,与苹果中变应原mal d1类似蛋白同源性高达66％。三级结构预测模型显示Sam a1含有T细胞主要抗原决定簇的C端α螺旋。实时定量PCR结果显示：黄瓜细菌性角斑病菌和NaCl溶液诱导下Sam a1的表达呈现上调趋势,表明Sam a1可能与病程相关蛋白和盐胁迫相关。Sam a1转入大肠杆菌M15后,表达出与预测蛋白大小相当的目标蛋白,IPTG诱导后5～7 h目标蛋白可大量表达。本研究为从植物分子机制上了解中药变态反应作用机制奠定了基础,尤其对中药产业的发展具有重要的意义。     

Genetic dissection of heading time and its components in rice

Heading time (HT, days from sowing to heading) is an important agronomic trait in rice. Physiologically, HT can be divided into two stages: vegetative growth time (VGT) and reproductive growth time (RGT). A number of studies for mapping QTLs conferring HT in rice have been reported, but none of them has tried to map HT-related QTLs based on their component traits (VGT and RGT). The present study aims to map HT-related QTLs in rice according not only to the performance of HT, but also the performances of VGT and RGT. A method based on an empirical equation of leaf age growth was developed to partition HT into VGT and RGT. An indica/japonica DH population and a corresponding RFLP map were constructed for the study. The methods of composite interval mapping and multiple-trait composite interval mapping were used to map QTLs. A total of 19 QTLs were mapped on all 12 rice chromosomes with the exception of chromosomes 1 and 4. Results showed that: (1) more QTLs could be detected by partitioning HT into VGT and RGT; (2) the genetic variation of HT was largely attributed to VGT; and (3) the two component stages were relatively independent in terms of QTL effects, suggesting that the ratio between VGT and RGT could be genetically adjusted without apparently altering HT. Received: 1 June 2000 / Accepted: 16 October 2000