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1.
A study of the intergenerational transmissibilities of 34 anthropometric measures from the Alexanderwohl Mennonite congregations of Kansas and Nebraska is presented. Results presented tend to confirm the suggestion made previously by us (Devor et al., 1985) that patterns of transmissibility conform to a concept of "functional multifactorial complexes" operating in the body in a way analogous to the "field" concept of dental morphology.  相似文献   

2.
Enzyme deactivation kinetics is often first-order. Different examples of first-order deactivation kinetics exhibited by different enzymes under a wide variety of conditions are presented. Examples of both soluble and immobilized enzymes are presented. The influence of different parameters, chemical modification of specific residues, inhibitors, inactivators, protecting agents, induced conformational changes by external agents, enzyme concentration, and different substrates on the first-order inactivation kinetics of different enzymes is analyzed. The different examples presented from a variety of different areas provides a judicious framework and collection demonstrating the wide applicability of first-order deactivation kinetics. Examples of reversible first-order deactivation kinetics and deactivation-disguise kinetics are also presented.Different mechanisms are also presented to model complex enzyme deactivations. The non-series type mechanisms are emphasized and these involve the substrate and chemical modifiers. Substrate-dependent deactivation rate expressions that are of "separable" and "non-separable" type are presented. Rate expressions involving time-dependent rate constants along with their corresponding mechanisms are presented. Examples of enzymes that exhibit a deactivation-free grace period are also given. An interesting case of enzyme inactivation is the loss of activity in the presence of an auto-decaying reagent. The method is presented by which the intrinsic inactivation rate constants may be obtained. Examples of pH-dependent enzyme inactivation are presented that may be modelled by a five-step (or a simplified two-step) mechanism, and also by a single-step mechanism involving residual activity for the final state. Appropriate examples of enzyme inactivation are presented in each case to highlight the different mechanisms involved.  相似文献   

3.
大蒜不同品种蒜薹发育的解剖学研究   总被引:3,自引:0,他引:3  
通过形态观测和石蜡切片法,比较了2个大蒜品种的蒜薹发育和解剖结构。结果表明:(1)“陇县火蒜”比“改良蒜”蒜薹的表皮细胞形状规则,排列致密;角质层较薄;(2)“陇县火蒜”比“改良蒜”蒜薹表面的气孔数量少,但开张度大;分泌细胞出现早、体积大、数量多;维管束数量少、直径小;(3)“陇县火蒜”蒜薹髓细胞卫多边形,髓细胞间隙率小,而“改良蒜”蒜薹的髓细胞呈椭圆形,髓细胞间隙率大。  相似文献   

4.
The results of a survey of 450 plastic surgeons regarding the practice of operating on their staff members is presented. An overwhelming majority (85 percent) of responding surgeons do operate on their staff. Whether surgery is a "right" of employment or a "reward" for service was addressed. Seventy-two percent felt surgery was a "reward," while only 8 percent felt it was a "right." The results found complications to be relatively minor but numerous (23.5 percent). The need for an office policy is stressed to help eliminate misunderstandings with other employees, and a model office policy is presented and endorsed.  相似文献   

5.
A brief review is presented of experimental studies conducted over several years (1970s–1990s) on the incretory potential of salivary glands, specifically on their role in the maintenance of carbohydrate homeostasis; a review is also presented of data on the stimulation of this potential by isoproterenol, a -adrenergic agonist.  相似文献   

6.
Data are presented for the first time on the quantitative distribution of pink salmon yearlings in the autumn period in the northwestern Sea of Japan that characterize one of the stages of salmon migrations toward wintering grounds. Data are presented concerning pink salmon wintering in near-bottom water layers near southwestern Sakhalin.Original Russian Text Copyright © 2005 by Biologiya Morya, Temnykh, Loboda, Ilinskii.  相似文献   

7.
Shnol' SE 《Biofizika》2001,46(5):773-774
The explanations to the special number of journal "Biophysics" are presented.  相似文献   

8.
The sequence of subfamilies,Cinchonoideae, Antirheoideae andRubioideae, attemps to show their natural affinities and phylogeny. The subfamilies are those ofVerdcourt, and the order in which they are presented is that ofBremekamp. A list is presented of the subfamilies, tribes and genera of theRubiaceae to be utilized in the Catálogo Ilustrado de las plantas de Cundinamarca, Colombia.  相似文献   

9.
通过对江河源区不同建植年限多年生人工草地植物群落的调查,分析了其土壤理化性状和土壤微生物数量的变化.结果表明:随着人工草地建植年限的增加,植物群落的数量特征多呈高-低-高、杂类草生物量低-高-底、莎草生物量增加的趋势;土壤养分变化为高-低-高、容重为低-高-底、pH呈下降趋势;土壤中多数微生物的数量及微生物生物量碳含量的变化为高-低-高,纤维素分解菌数量逐渐升高,而反硝化菌数量逐年下降,溶磷菌数量呈低-高-低的动态变化.土壤微生物数量与土壤理化性状存在明显的相关关系,各生理类群明显受不同土壤理化因素的直接控制和间接调节.说明人工草地的建植及其正向恢复演替改善了土壤的理化性状,使土壤环境有利于有益微生物菌群的定居繁殖,有害微生物菌群的增殖受到抑制.  相似文献   

10.
Summary A comparison of the EPOS leg 3 material of Weddell Sea Isopoda with the known literature data revealed some new results for the horizontal and vertical distribution of isopods in the eastern Weddell Sea. The number of isopod species known for the Weddell Sea almost doubled to 118 species. New results on the vertical distribution of 11 isopod genera are presented.Data presented here were collected during the European Polarstern Study (EPOS) sponsored by the European Science Foundation  相似文献   

11.
Summary Ammonium fertilizer applied to tea soils is readily converted to nitrate by the nitrifying bacteria in soil. Excess nitrate in soil could undergo rapid leaching losses under high rainfall conditions. Data is presented in this paper to show that waste tea could be effectively used to retard and delay nitrate production and thereby prevent loss of nitrogen as nitrate by leaching. Evidence is also presented to show that waste tea readily liberates ammonium nitrogen in soil.  相似文献   

12.
13.
Chemical fingerprinting of plants   总被引:1,自引:0,他引:1  
The chemical fingerprinting of a plant demands the determination of a large number of elements at background level but also in polluted regions and in relation to other species. The most important stages of the development of plant fingerprints are mentioned in this paper and a short survey of the state of the art is presented. Examples on fingerprinting of lichens, mosses, Taraxacum officinale and Populus nigraItalica are presented.  相似文献   

14.
A radioimmunoassay for Prostaglandin F which utilizes polyethylene glycol to separate antibody-bound and free prostaglandin is discribed. The detailed procedure for extraction and chromatographic fractionalization of the "E" and "F" series is presented. The recoveries of labeled prostaglandin obtained at each step of the procedure compared favorably with the 68% overall recovery figure for the complete assay. Data on the sensitivity, specificity, accuracy and reproducibility of the assay are presented. PgF levels in plasmas obtained from normal males and females, pregnant females in the third trimester and females in labor have been determined. Ovarian and uterine tissue levels of Prostaglandin F are also included.  相似文献   

15.

Background

Several recent studies have revealed that words presented with a small increase in interletter spacing are identified faster than words presented with the default interletter spacing (i.e., w a t e r faster than water). Modeling work has shown that this advantage occurs at an early encoding level. Given the implications of this finding for the ease of reading in the new digital era, here we examined whether the beneficial effect of small increases in interletter spacing can be generalized to a normal reading situation.

Methodology

We conducted an experiment in which the participant’s eyes were monitored when reading sentences varying in interletter spacing: i) sentences were presented with the default (0.0) interletter spacing; ii) sentences presented with a +1.0 interletter spacing; and iii) sentences presented with a +1.5 interletter spacing.

Principal Findings

Results showed shorter fixation duration times as an inverse function of interletter spacing (i.e., fixation durations were briefest with +1.5 spacing and slowest with the default spacing).

Conclusions

Subtle increases in interletter spacing facilitate the encoding of the fixated word during normal reading. Thus, interletter spacing is a parameter that may affect the ease of reading, and it could be adjustable in future implementations of e-book readers.  相似文献   

16.
1. Evidence is presented for the occurrence of a very stable RNA core (S4-RNA) in "native" 16S RNA that is also present in the 30S subunit of Escherichia coli. A model giving the approximate location of this RNA core in the 30S subunit is presented. 2. It is proposed (a) that this S4-RNA acts as a nucleus for the assembly of the 30S subunit, and (b) that a small class of "linkage" proteins, including S4, further facilitate the assembly of the proteins to the RNA, thereby explaining some of the "cooperative" effects that are observed during in vitro assembly. 3. Evidence for the importance of the RNA core in the functioning of the ribosome is discussed.  相似文献   

17.
The latent periods of saccadic eye movements in response to peripheral visual stimuli were measured in 8 right-handed healthy subjects using Posner's paradigm "COST-BENEFIT". In 6 subjects, the saccade latency in response to visual target presented in expected location in valid condition was shorter than that in neutral condition ("benefit"). Increase in saccade latency in response to the visual target presented in unexpected location in valid condition versus neutral condition took place only in 4 subjects ("cost"). A decrease in left-directed saccade latency in response to expected target presented in the left hemifield and increase in saccade latency in response to unexpected left target in comparison with analogous right-directed saccades were observed in valid condition. This phenomenon can be explained by the dominance of the right hemisphere in the processes of spatial orientation and "disengage" of attention.  相似文献   

18.
In the development of discussion on epidemiological terms containing definitions "epidemic" and "epidemiological" variants of these terms as used in electronic documents placed on Internet sites are considered. Both most common combinations and contradictions in the use of some terminological constructions are presented.  相似文献   

19.
The structure of the dinoflagellate chromosome is examined using spread whole mounts and serial sectioning. Evidence is presented that the chromosome is composed of a toroidal bundle of DNA strands which is coiled plectonemically into a tight double helix. This structure is apparent in interphase whole-mount chromosomes and by careful analysis of serial sectioning can be shown in all mitotic stages. It is particularly apparent in the arms of replicating Y shaped chromosomes which often uncoil slightly (either naturally or as a result of the fixation used). A model is presented which is based on these results and recent genetic and biochemical data.  相似文献   

20.
A profusion of terms are currently used to describe free flap wound closure. It is important to broadly standardize nomenclature when embarking on a comparison of functional outcomes between institutions. Therefore, a series of 68 "emergency" (within 24 hours) free flaps performed by a single surgeon were reviewed with respect to a total experience of 188 free tissue transfers to formulate a consistent nomenclature applicable to free flap wound closure in general. The nomenclature presented divides free flap closure into three categories: "primary free flap closure" (12 to 24 hours), "delayed primary free flap closure" (2 to 7 days), and "secondary free flap closure" (after 7 days). This system is analogous to the standard terms "primary," "delayed primary," and "secondary wound closure." It is consistent with known biologic and microbiologic principles of wound closure in general and should provide a simple basis for classifying free flap wound closure. Illustrative examples are presented to highlight the classification scheme.  相似文献   

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