Regarding the confusion between the population concept and Mayr's "population thinking"

Ernst Mayr said that one of Darwin's greatest contributions was to show scholars the way to population thinking, and to help them discard a mindset of typological thinking. Population thinking rejects a focus on a central representative type, and emphasizes the variation among individuals. However, Mayr's choice of terms has led to confusion, particularly among biologists who study natural populations. Both population thinking and the concept of a biological population were inspired by Darwin, and from Darwin the chain for both concepts runs through Francis Galton who introduced the statistical usage of "population" that appears in Mayr's population thinking. It was Galton's "population" that was modified by geneticists and biometricians in the early 20th century to refer to an interbreeding and evolving community of organisms. Under this meaning, a population is a biological entity and so paradoxically population thinking, which emphasizes variation at the expense of dwelling on entities, is usually not about populations. Mayr did not address the potential for misunderstanding but for him the important part of the population concept was that the organisms within a population were variable, and so he probably thought there should not be confusion between population thinking and the concept of a population.     

Exploring the limiting causes of fruit production in the tropical tree Ipomoea wolcottiana Rose (Convolvulaceae)

Path analysis was used to evaluate a group of variables related to fruit production in the tropical tree Ipomoea wolcottiana (Convolvulaceae). The variables were tree size (trunk diameter), available phosphorus in the soil, floral phenotypic sex expression (i.e. gynoecium biomass allocation), flower production, fruits initiated, and length of the corolla and diameter of its opening. The path model explained 79.9% of the total variation, and the production of mature fruits was related in large part by the number of fruits initiated and by phenotypic sex expression. In turn, fruits initiated were related to corolla tube diameter and to a lesser extent to corolla tube length. The model could explain a low percentage of the variation (18.5%) of the number of fruits initiated, but once a fruit was initiated it had a high probability of maturing. Phenotypic sex expression related negatively to the number of flowers produced and positively, to almost the same degree, to available phosphorus in the soil. Tree size had a positive effect on flower production but a negligible effect on fruits initiated and matured. Soil phosphorus affected positively, although weakly all variables. The relationships between tree size, number of flowers and phenotypic sex expression suggested that abundant flowering in this species functions more for pollen donation than its reception.     

For the Eightieth Anniversary of the Birthday of V.V. Davydov (1930-1998)

The article is dedicated to the eightieth anniversary of the birth of an outstanding psychologist and educator, V.V. Davydov, who (together with D.B. Elkonin) worked out the psychological principles and pedagogical practice of developmental education. The center of the program they worked out was the development of theoretical thinking and the formation in schoolchildren of a readiness to think and ability for conceptual thinking. The article tries to apply the notions of theoretical thinking developed by Davydov to an analysis of thinking per se. The most attention is focused on reflection and intuition.     

心力衰竭状态下的动脉压力感受器反射

心力衰竭是以心脏泵血功能降低（心输出量减少）为始动因素的临床综合征。心输出量降低首先引起动脉压力感受性反射失负荷,进而通过迷走-交感机制加快心率;同时,支配血管床的交感传出活动增强,进而增加总外周阻力。本文主要论述在心力衰竭状态下压力感受性反射在循环功能异常调控中的作用机制。本综述及我们近年的研究表明：（1）在心力衰竭状态下压力感受性反射功能明显减弱;（2）中枢血管紧张素Ⅱ和活性氧在压力感受性反射功能失调中发挥关键作用;（3）心交感传入刺激和化学感受性反射能抑制压力感受性反射;（4）适当的运动可以部分纠正异常的心血管反射活动。     

A practical view of 'druggability'

The introduction of Lipinski's 'Rule of Five' has initiated a profound shift in the thinking paradigm of medicinal chemists. Understanding the difference between biologically active small molecules and drugs became a priority in the drug discovery process, and the importance of addressing pharmacokinetic properties early during lead optimization is a clear result. These concepts of 'drug-likeness' and 'druggability' have been extended to proteins and genes for target identification and selection. How should these concepts be integrated practically into the drug discovery process? This review summarizes the recent advances in the field and examines the usefulness of 'the rules of the game' in practice from a medicinal chemist's standpoint.     

Phylogenetic thinking in the modern biology

Any research activity is conducted within the framework of a cognitive situation which is defined by certain basic assumptions about ontology of the portion of the objective world under investigation. From the standpoint of the non-classical scientific epistemology, a part of that situation is constituted by personal knowledge which is formed by a set of thinking (cognitive) styles. The scholastic thinking existing in taxonomy and phylogenetics is considered as an example showing unavoidability of such styles in the natural history knowledge. It is initially rooted in the antic, mythological by its essence, persuasion of isomorphism between movements of the objective reality and of the mind. The instrumentalism entailed by scholastic thinking is based on the mythologeme according to which the "right method" par excellence can lead to the "right knowledge". That is why any disputes between different numerical methods of phylogenetic reconstructions are vain: their validity could be assessed not formally but within particular cognitive situations formed by particular basic models of the phylogenesis. Phylogenetic thinking is of the key importance in evolutionary biology and has great impact on various fields of biology based on it. It is pretty mythological because of non-observability of the phylogenesis: the latter is rather "thinked-in" in the objective world then is induced from the observed facts. It constitutes a part of the evolutionary thinking considering mainly macroevolutionary trends and stressing the initial causes in the structure of causal relations in the analyses of the diversity of organisms. The "tree thinking" of O'Hara is its rough operational equivalent. Relation between phylogenetic thinking and some other styles are considered, which are population, phenetic, typological, and epigenetic ("developmental" of O'Hara). Phylogenetic thinking makes it obliged inclusion of the initial causes in the explanatory models which underlie adaptive and functional peculiarities of organisms, as well as of the entire structure of the biodiversity. It manifests itself in such kind of models through uncovering the phylogenetic signal. This thinking style has great effect on understanding of the ontology of taxa and acknowledges the objective status of the phylogenetic pattern. It is intrinsically included in the argumentation schemes of constructional morphology, comparative phylogenetics. The central metaphor of the phylogenetics is the Tree of Life. Emagination of its unity and uniquiness is of naturphilosophical nature. From the contemporary epistemological standpoint, it should be considered as a generalization upon partial hypotheses of evolution of particular structures each corresponding to certain consideration aspect of the global phylogenesis. Acknowledging of multi-aspectness of the phylogenesis constitutes one of the important points of modern phylogenetic thinking. As different semogeneses are incompletely congruent, the Tree of Life is less certain than each of the initial hypotheses. Any attempt to make it more resolved would lead to its reduction to any of the particular semogenetic scheme (i.e. to a "gene tree") or to its "decay" into several trees each corresponding to a particular consideration aspect of the global Tree.     

Homeosis, morphogenetic gradient and the determination of floral identity in the inflorescences ofPhilodendron solimoesense (Araceae)

A comparative developmental study of the inflorescence ofPhilodendron solimoesense was conducted using scanning electron microscopy. The spadix ofP. solimoesense is characterized by unisexual flowers. Staminate flowers are initiated on the upper portion of the spadix while pistillate flowers develop on the lower portion of the spadix. An intermediate zone located between the upper male and lower female portion of the inflorescence consists of sterile male flowers. Within this intermediate zone a row of flowers exhibit polarity with respect to the identity of sexual organs. Stamens are initiated on the flank of the floral meristem facing the upper male zone and carpels are initiated on the portion of the floral meristem facing the lower female zone. The resulting flowers therefore assume a bisexual identity. At the level of the inflorescence, all floral buds are initiated along a series of contact parastichies and the continuity of these parastichies is not disrupted at any level in the male, intermediate, and female zones on the spadix. Results from this study support the presence of a morphogenetic gradient acting at the level of the inflorescence and appears to be independent of the boundaries of floral primordia.     

Evidence suggesting that the mouse sperm acrosome reaction initiated by the zona pellucida involves an alpha7 nicotinic acetylcholine receptor

The mammalian sperm acrosome reaction (AR) is essential to fertilization and is believed to be initiated in vivo by ZP3, a glycoprotein component of the egg zona pellucida (ZP). Recently, we reported the results of antagonist studies suggesting that a nicotinic acetylcholine receptor (nAChR) containing an alpha7 subunit (alpha7nAChR) plays a role in the human sperm AR initiated by recombinant human ZP3 or by acetylcholine (ACh). Here, we show that ACh can initiate the mouse sperm AR and that antagonists of the nAChR inhibit the AR initiated by ACh or by ZP obtained from ovarian oocytes (isolated heat-solubilized mouse ZP). Preincubation with three antagonists of the nAChR, alpha-bungarotoxin (100 nM), alpha-conotoxin IMI (100 nM), and methyllycaconitine (100 nM), significantly blocked AR initiation by ACh or by isolated heat-solubilized mouse ZP (P 相似文献   

A p-Adic model for the process of thinking disturbed by physiological and information noise

We develop a model of the process of thinking in the presence of noise (which is produced by the simultaneous action of a huge number of neurons in the brain as well as by external information and internal cognitive processes). Our model is based on Freud's idea on the splitting of cognitive processes into two (closely connected) domains: consciousness and subconsciousness. We represent the process of thinking as a random dynamical process in a space of ideas endowed with a non-Euclidean geometry (which differs extremely from the ordinary Euclidean geometry of spatial location of neurons in the brain). The so-called p-adic geometry on a space of ideas describes the ability of cognitive systems to form associations. We show that random dynamical thinking systems on a p -adic space of ideas still generate only deterministic ideas. We also study positive and negative effects of noise (in particular, creativeness and stress).     

Fruit abortion and the regulation of fruit number in Yucca whipplei

Summary Flowering and fruiting patterns of Yucca whipplei (Agavaceae), a monocarpic perennial of the southern California chaparral, were studied to determine the role of fruit abortion in the regulation of seed yield. Data on reproductive expenditure, fruit abortion and fruit maturation were obtained for 108 flowering individuals at two sites. The proportion of flowers maturing fruits was less than 10% at both sites. Inflorescences produced an average of 2,045±111 and 1,743±77 flowers at the two sites, initiated an average of 439±48 and 304±21 fruits, and matured an average of 194±16 and 162±10 fruits, respectively. Overall, 51% of the fruits which initiated development were aborted and abscized in an early stage of development.The hypothesis that fruit abortion serves to regulate seed yeild, matching fruit production to the available resources, yields three predictions which are borne out by our findings: (1) the proportion of initiated fruits which abort is an increasing function of the number of fruits initiated, (2) the number of fruits matured is an increasing function of estimates of the amount of resources available to support fruits, and (3) on any inflorescence, fruits initiated early have a lower probability of aborting than fruits initiated late.These results suggest that low fruit set in Yucca whipplei is caused by shortage of resources to support developing fruits, rather than by a shortage of pollinators. Possible explanations of the adaptive significance of regulating maternal investment via fruit abortion are mentioned, but further experimentation is required before any conclusions can be drawn.     

Influence of oligomer chain length on the antioxidant activity of procyanidins

The antioxidant activity of catechin monomers and procyanidin (dimers to hexamers) fractions purified from cocoa was studied in two in vitro systems: liposomes and human LDL. Liposome oxidation (evaluated as formation of 2-thiobarbituric acid reactive substances) was initiated with 2,2'-azobis (2-amidinopropane) hydrochloride (AAPH), 2,2'-azobis (2,4-dimethylvaleronitrile) (AMVN), iron/ascorbate, or UV-C; LDL oxidation (evaluated as formation of conjugated dienes) was initiated with Cu(2+) or AAPH. Catechin monomers and procyanidin fractions inhibited both liposome and LDL oxidation. Monomers, dimers, and trimers fractions were the most effective antioxidants when liposome oxidation was initiated in the aqueous phase. When oxidation was initiated in the lipid domains, higher molecular weight procyanidins were the most effective. All fractions significantly inhibited Cu-mediated LDL oxidation; no significant effect of procyanidin molecular weight was observed. The hexamer fraction was the least effective with respect to preventing AAPH initiated LDL oxidation. Results reported herein give further evidence on the influence of the oligomer chain length on the antioxidant protection by procyanidins.     

Features of spatial organization of EEG and psychophysiological characteristics of the person with the divergent and convergent types of thinking

The psychophysiological indicators of spatial synchronization of biopotential at different types of mental processes in humans: non verbal-divergent, nonverbal-convergent, verbal-divergent and verbal-convergent were analyzed. The unequal relationship between the productivity of the implementation of tests on these types of thinking was revealed. The closest significant correlation exists between the productivity of the verbal-divergent and verbal-convergent thinking, and the lowest--between the productivity of nonverbally-divergent and nonverbally-convergent thinking. The differences in the topographical maps of the spatial synchronization of biopotential at different types of thinking was marked. They are most pronounced in the implementation of two non-verbal tasks, minimal--in two verbal tasks. Differences between different types of thinking are also manifested in the degree of coherence gain biopotential of the performance tests in comparison with the background (open eyes). Some physiological properties of the person that contribute to the divergent (creative) tests have a negative impact on the implementation of converged (tedious) tests. The findings are discussed in terms of differences in the level of general activation and participation of different ways of processing information (simultaneous and successiveness).     

Ultraweak luminescence of blood plasma in experimental embolism of the main arteries of the limbs

The changes in the level of blood plasma chemiluminescence initiated by hydrogen peroxide and divalent iron were studied in experiments on 15 dogs with aorta bifurcation embolism. After occlusion of the arteries the level of iron-initiated chemiluminescence decreases. The level of hydrogen peroxide-initiated luminiscence increases simultaneously, reaches the maximum after 6-hour occlusion and subsequently tends to decrease. Hydrogen peroxide-initiated statistically significant increase in luminescence allows one to form a judgement about duration of the disease. After blood flow recovery in the limbs there take place a rise in the level of hydrogen-peroxide initiated hemiluminescence and subsequent iron-initiated hemiluminescence level drop.     

Consequences of foundress aggregation in the brown citrus aphid Toxoptera citricida

1. A field study was conducted in which colonies of Toxoptera citricida (Kirkaldy) were initiated with different numbers of foundresses on ungrafted citrus trees var. ‘Carrizo’ within an existing citrus grove in central Florida. 2. The growth rate, longevity, and final size of T. citricida colonies were all positively correlated with number of foundresses. 3. Colonies initiated by many foundresses produced alatae earlier than those initiated by fewer foundresses. 4. Nymphal developmental time was reduced in colonies initiated by more foundresses but the mean number of grand‐progeny per foundress was lower when only surviving colonies were compared. 5. The longevity of foundresses was unaffected by their number but foundress fecundity and nymphal survival decreased as foundress number increased. 6. The most abundant natural enemies were Diptera: Syrphidae, primarily Pseudodorus clavatus (F.), and Chamaemiidae (Leucopis sp.), followed by Coleoptera: Coccinellidae, primarily Cycloneda sanguinea (L). 7. Colonies initiated with more foundresses attracted more oviposition by dipteran predators than did colonies initiated with fewer foundresses.     

Consequences of a changing environment on the breeding phenology and reproductive success components in a long-distance migratory bird

Migratory birds have a narrow time window to breed, especially in the Arctic, where early nesting typically yields the highest reproductive success. We assessed temporal changes (1991–2015) in reproductive success components in relation to timing of breeding in greater snow geese (Chen caerulescens atlantica). This species breeds in the Canadian Arctic, a region that has experienced a strong warming trend. We tested the effect of laying or hatching date, year and their interaction on six reproductive components: Total clutch laid, nesting success, egg survival, hatching success, prefledging, and postfledging survival. Over 25 years, mean laying date changed little, even though it advanced 1.8 days in early breeders and was delayed 3 days in late breeders. Likewise, the number of eggs in nests initiated early in the season decreased by 0.6 egg, whereas in late nests it increased by 0.3 egg. Success of nests initiated early and late in the season was lower than nests initiated near the population mean, and consistently increased over time. The proportion of eggs surviving to partial predation and postfledging survival decreased with laying date but the pattern did not change over time. In contrast, prefledging survival was not affected by laying date initially but declined in nests initiated late in the season toward the end of the study. Overall, nests initiated close to the population mean showed little temporal change for most components of reproductive success and seem to be less affected by environmental change than nests initiated early and late in the season.     

Micropropagation of the medicinal plant, Scilla natalensis Planch.

Primary bulb explants of Scilla natalensis were cultured in vitro on modified MS medium. Some of these explants initiated shoots, which provided a sterile source of secondary leaf and bulb explants. The secondary explants responded similarly to various combinations of plant growth regulators. Shoots were initiated spontaneously on medium containing no plant growth regulators. The number of shoots initiated was increased by the addition of kinetin or thidiazuron (TDZ) alone, but was reduced by the addition of indole-3-acetic acid (IAA) or naphthalene acetic acid (NAA) alone. Optimal shoot initiation occurred on medium containing 1 to 2 mg l^–1 kinetin and 1 to 2 mg l^–1 IAA. These shoots were rooted on medium containing 1 mg l^–1 IAA. The plantlets were successfully acclimatised in the misthouse/shadehouse.     

景观设计思维的培养途径与教学探讨——从设计思维的特性谈起

作为一门以落地性为特征的应用型学科,对学生规划设计思维与能力的培养一直是风景园林专业教学的重要目标,如何通过教学有效地培养学生规划设计思维与能力也成为了风景园林专业教育关注的重要议题。本文从设计思维的特性出发,针对设计教学课程提出了一套控制方式和流程,并以同济大学本科三年级上学期的公园设计课程为例,对景观设计思维的培养途径和方法展开了教学尝试。     

Mitotic regulation of the human anaphase-promoting complex by phosphorylation

The anaphase-promoting complex (APC) or cyclosome is a ubiquitin ligase that initiates anaphase and mitotic exit. APC activation is thought to depend on APC phosphorylation and Cdc20 binding. We have identified 43 phospho-sites on APC of which at least 34 are mitosis specific. Of these, 32 sites are clustered in parts of Apc1 and the tetratricopeptide repeat (TPR) subunits Cdc27, Cdc16, Cdc23 and Apc7. In vitro, at least 15 of the mitotic phospho-sites can be generated by cyclin-dependent kinase 1 (Cdk1), and 3 by Polo-like kinase 1 (Plk1). APC phosphorylation by Cdk1, but not by Plk1, is sufficient for increased Cdc20 binding and APC activation. Immunofluorescence microscopy using phospho-antibodies indicates that APC phosphorylation is initiated in prophase during nuclear uptake of cyclin B1. In prometaphase phospho-APC accumulates on centrosomes where cyclin B ubiquitination is initiated, appears throughout the cytosol and disappears during mitotic exit. Plk1 depletion neither prevents APC phosphorylation nor cyclin A destruction in vivo. These observations imply that APC activation is initiated by Cdk1 already in the nuclei of late prophase cells.     

Topic analysis: an objective measure of the consultation and its application to computer assisted consultations.

A simple method has been developed to classify the verbal interaction during medical consultations in terms of the relative proportions of medical and social content and the initiator of conversational topics discussed. The method has been applied to video tape recordings of three doctors'' consultations with and without a computer present to classify and compare the items discussed. Actual computer use has been shown to have a medical effect on the consultations (p less than 0.05) and to increase the proportion of topics initiated by the doctor (p less than 0.001). Although this was largely accounted for by the massive increase in doctor initiated medical items resulting directly from computer use, there was evidence that, for two of the doctors, these topics were replacing some of the normal social and patient initiated medical exchanges.