In vitro separation of a rose chimera

“Fairmount 1 thorny” (“FM1 thorny”) (a Rosa multiflora Thunb ex. J. Murr.) and a thornless sport of “FM1 thorny” (“Fairmount 1” (“FM1”)) were established in vitro to investigate chimeral segregation under various levels of BA and to obtain a pure thornless rose. While the chimeral thornless sport was expected to segregate in vitro and yield both thorny and thornless plantlets, “FM1 thorny” was to yield only thorny plants. “FM1” segregated in vitro into its constituent genotypes and yielded thorny and thornless plantlets, suggesting that “FM1” is chimeral. “FM1 thorny” produced only thorny plants in vitro. These results indicate that the “FM1 thorny” clone was not chimeral (pure thorny) and that the thornless regenerates of “FM1” did not develop via somaclonal variation. There was a significant linear relationship between increasing BA concentration and the percentage of thorny plants. Among a population of 690 tissue culture derived plants from all the BA experiments, 6 plants were classified as pure thornless plants 1 year later.     

Nitric oxide and hydrogen cyanide as regulating factors of enzymatic antioxidant system in germinating apple embryos

Short-term (3 or 6 h) pre-treatment of apple (Malus domestica Borkh.) embryos with nitric oxide (NO) or hydrogen cyanide (HCN) induces transient accumulation of reactive oxygen species (ROS) leading to dormancy removal and germination. We demonstrated that enhanced NO emission by apple embryos during early phase of germination “sensu stricto” is required for seed transition from dormant into non-dormant state, and may be described by the model of “nitrosative door”, analogous to “oxidative window”. Cellular ROS concentration, resulting from NO or HCN embryo pre-treatment, seems to be under severe control of antioxidant system. Activity of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPX) and total peroxidases (Prxs) was determined during NO and HCN-mediated germination “sensu stricto” of embryos. CAT and SOD activity increased transiently 24 h after embryos pre-treatment, while GR and Prx activity was stimulated mainly after 96 h. The most evident alterations were detected in GPX activity, being more than threefold stimulated by NO or HCN. Based on this results, we conclude that these reactive molecules act simultaneously crossing their signaling pathways and we propose that ROS, reactive nitrogen species, HCN at accurate level are essential during seed germination as signaling factors.     

Morphological hemiplasies in cladistic studies of phylogeny,with examples from birds

Cladograms usually include many evolutionary reversions, parallelisms, and convergences united under the term homoplasy. Recently, it has become evident that molecular traits that look like homoplasy may be in fact true homologies. The processes of independent sorting of genes, which provide the basis of these events, were recently termed hemiplasy. The present study demonstrates theoretical possibility of independent manifestation of true homology (synapomorphy) in remote lineages of phylogenetic tree, as morphological characters are analyzed; this phenomenon is similar in manifestation (but not in nature) to hemiplasy. In the case of “morphological hemiplasy,” characters that appeared only once in evolution may formally be treated by a cladist as parallelisms, since they occur in remote lineages of phylogenetic tree. It is proposed that “morphological hemiplasy” is responsible for a number of uncertain cases in avian phylogeny. Examples are provided by the ducklike bill in Paleogene Presbyornithidae and extant Anatidae and Anseranatidae (Anseriformes), the apomorphic structure of the flying apparatus in Paleogene Jungornithidae (Apodiformes) and extant Trochilidae, and “independent” development of a highly-modified zygodactyl foot in Zygodactylidae and Pici.     

Laminin provides a better substrate than fibronectin for attachment,growth, and differentiation of 1003 embryonal carcinoma cells

Summary Culture of cells in hormonally defined media has allowed (a) the demonstration of physiological responses from cells usually unable to express them in vitro and (b) the study of the effects on growth and differentiation of diffusible factors and attachment factors. The embryonal carcinoma line 1003 forms multidifferentiated tumors in vivo but is unable to differentiate in vitro when grown in serum-containing medium. In a defined medium containing insulin, transferrin, selenium, and fibronectin as attachment factors, 1003 cells grow for several generations and differentiate into neurons and embryonic mesenchyme (Darmon et al., 1981, Dev. Biol. 85: 463–473). In the present work the effects of fibronectin and laminin were compared. In the presence of laminin the cells attached and spread better, grew faster, and could be plated at lower densities. Neurite extension was also better under these conditions and most importantly, it was found that laminin induced an important formation of muscular tissue when the cells had been seeded at low densities. Multinucleated myotubes could be stained with antibodies directed against embryonic muscular myosin. Coating the dishes with polylysine or adding FGF or serum-spreading factor to the medium allowed growth of low-density cultures with fibronectin instead of laminin but muscular differentiation was not detected under these conditions. Addition of fibronectin to laminin-containing medium did not inhibit muscular differentiation. Presented in the symposium on Plant and Animal Physiology in Vitro at the 33rd Annual Meeting of the Tissue Culture Association, San Diego, California, June 6–10, 1982. This research was supported in part by grants from the “Centre National de la Recherche Scientifique” (LA 269), the “Délégation Générale à la Recherche Scientifique et Technique,” the Fondation pour la Recherche Médicale Fran?aise,” the “Institut National de la Santé et de la Recherche Medicale,” the “Ligue Nationale Fran?aise centre le Cancer,” and the “Fondation André Meyer.” This symposium was supported in part by the following organizations: Bellco Glass, Inc., California Branch of the Tissue Culture Association, Collaborative Research, Hana Media, Hybridtech, K C Biological, Inc., and Millipore Corporation.     

Dynamics of cardiac performance in athletes during isometric exercise

The main structural-functional indices of cardiac performance during isometric exercise were recorded in athletes and non-athletes. The physiological shifts in response to exercise were less obvious in the athletes than in the non-athletes. This was mainly determined by the structural features of the “athlete’s heart.” The dependence of a series of physiological indices on the heart rate was revealed: as cardiac rhythm increased in response to a submaximal isometric exercise, the systolic and, to a lesser degree, diastolic arterial pressure grew and the stroke volume of blood decreased.     

Carbohydrate tolerance,serum albumin and protein values of normal and “waster” marmosets (Callithrix jacchus)

The major objective of this study was to establish standard glucose and lactose tolerance curves for the common marmoset (Callithrix jacchus). These data were utilized to establish criteria for detection of abnormal glucose tolerance and characterization of some aspects of the “marmoset wasting syndrome” which has been observed in this species. Glucose and lactose tolerance tests were performed on healthy animals and typical “marmoset wasters.” Eighteen normal animals were 18 to 36 months old and weighed 194–280 g. Six “wasters” were in the age range of 24 to 84 months and weighed 163–253 g. Seven experiments were carried out for each glucose tolerance test. In each trial it was observed that the serum glucose concentration (SGC) of the healthy animal after 90 min was two times higher than the pre-administration concentrations. The SGC returned to the pre-administration concentration within 150–300 min in animals administered glucose at dosages of 2 g/kg and 1 g/kg of body weight. However, at the dosage level of 5 g/kg body weight, the SGC of the animals tripled after 30 min and required 300 min to return to the pre-administration level. The 2 g/kg dosage level was chosen as typical. When similar experiments were conducted with animals identified as “chronic wasters,” all of the animals except one were observed to be inefficient in the absorption of glucose. When lactose was administered at a level of 4 g/kg, similar results were obtained. Normal and “waster” marmosets were also subjected to serum total protein, albumin and electrophoresis determinations in an effort to establish additional criteria that may be utilized in the identification of the “marmoset wasting” syndrome. Serum albumin was significantly higher in the “waster” marmosets 30 min following an oral administration of glucose than was observed in normal animals. Total protein values were not significantly lower in the “wasters” when subjected to the same tolerance test. The albumin level in normal animals was not affected by similar glucose tolerance tests. The electrophoretic patterns of serum protein for normal animals exhibited more bands than was observed in patterns of serum protein for “waster” marmosets. From these data, it seems logical that these diagnostic tests may be useful in developing a profile for the early detection of the “wasting” syndrome in marmosets.     

Pollination biology of <Emphasis Type="Italic">Disanthus cercidifolius</Emphasis> var. <Emphasis Type="Italic">longipes</Emphasis>, an endemic and endangered plant in China

Disanthus cercidifolius Maxim. var. longipes H.T. Chang usually has two inflorescences growing in opposite directions in the axillae, but occasionally three inflorescences grow paratactically. The typical flowering process could be divided into 4 periods: “Pre-dehiscence”, “Initial dehiscence”, “Full dehiscence” and “Withering”. Both the natural population and the planted population had a flowering peak of 15–35 days after the first flower bloomed. There were significant differences between the time courses of flowering of the two populations. Out-crossing is the main breeding system in this species. And autogamy decreases the risk of reproductive failure of this species. The main insect pollinators of D. cercidifolius var. longipes are Episyrphus balteatus de Geer, Scaptodrosophila coracina Kikkawa and Peng, Polistes olivaceus de Geer, Apis cerana Fabricius, Nezara viridula L. and Coccinella septempunctata L., and so on. Among the insects, S. coracina and E. balteatus are the most important and efficient pollinators, but others are inefficient pollinators. Though wind pollination is not efficient, it guarantees reproduction when insect pollinators are not available. “Mass flowering” is an adaptive behavior and reproductive strategy of this species, and “few fruiting” could be caused by the lack of pollinators.     

Physiological bases of oligotrophy of microorganisms and the concept of microbial community

Three groups of physiological processes in microorganisms are considered the physiological basis of oligotrophy: the greater substrate affinity of the oligotrophs' transport systems, efficient or “economical” metabolism, and existence of a “master reaction” or “rate-determining steps” controlling the rate of metabolism. Heterotrophic microorganisms are divided into three unequal groups according to “reaction norma.” Two groups representing the extremes are small groups with the “narrow” reaction norma, regarding the concentrations and structure of the assimilated organic compounds and variability limits of the physiological characteristics mentioned above. The third, intermediate group includes the majority of microorganisms with the “wide” reaction norma.     

Sexes,species, and genomes: why males and females are not like humans and chimpanzees

This paper describes, analyzes, and critiques the construction of separate “male” and “female” genomes in current human genome research. Comparative genomic work on human sex differences conceives of the sexes as like different species, with different genomes. I argue that this construct is empirically unsound, distortive to research, and ethically questionable. I propose a conceptual model of biological sex that clarifies the distinction between species and sexes as genetic classes. The dynamic interdependence of the sexes makes them “dyadic kinds” that are not like species, which are “individual kinds.” The concept of sex as a “dyadic kind” may be fruitful as a remedy to the tendency to conceive of the sexes as distinct, binary classes in biological research on sex more generally.     

Consistency of optimal sequence alignments

Pairwise optimal alignments between three or more sequences are not necessarily consistent as a whole, but consistent and inconsistent residues are usually distributed in clusters. An efficient method has been developed for locating consistent regions when each pairwise alignment is given in the form of a “skeletal representation” (Bull. math. Biol. 52, 359–373). This method is further extended so that the combination of pairwise alignments that gives the greatest consistency is found when possibly many alignments are equally optimal for each pairwise comparison. A method for acceleration of simultaneous multiple sequence alignment is proposed in which consistent regions serve as “anchor points” limiting application of direct multi-way alignment to the rest of “inconsistent” regions. Dedicated to Prof. Akiyoshi Wada on the occasion of his 60^th birthday.     

Evolutionary ecology of clonal-bisexual complexes in spined loaches from genus <Emphasis Type="Italic">Cobitis</Emphasis> (Pisces,Cobitidae)

The objective of this work was to analyze several aspects of evolutionary ecology of the spined loach clonal-bisexual complexes. This analysis demonstrates that the twofold population growth rate in clonal forms compared with bisexual species is not a proper feature of spined loaches, because their clonal forms are polyploids with the larger eggs and correspondingly the lower individual fecundity. Both the larger nutrient stores in eggs and the larger hatchlings provide certain ecological advantages for clonal spined loach triploids at early stages of their ontogeny and possibly ensure the higher fitness in a local environment. The clonal-bisexual spined loach complexes have reduced structure usually including one bisexual species and the only clonal form. This reduction may be caused by several factors: 1) the competition between different forms and subsequent superseding of some of them; 2) a particular manner of colonization of new areas by different bisexual and clonal forms; 3) the absorption of one of parental species for hybrid origins of clonal forms (hypothesis of absorption). The relative numbers of bisexual and unisexual forms in different clonal-bisexual complexes depend on “family ties” between clonal forms and “host” bisexual species; their ratios are subjected to temporal dynamics caused by both external (environmental changes) and internal (automatic fluctuating) factors.     

Sibling rivalry between seeds within a fruit: Some population genetic models

Competition between seeds within a fruit for parental resources is described using one-locus-two-allele models. While a “normal” allele leads to an equitable distribution of resources between seeds (a situation which also corresponds to the parental optimum), the “selfish” allele is assumed to cause the seed carrying it to usurp a higher proportion of the resources. The outcome of competition between “selfish” alleles is also assumed to lead to an asymmetric distribution of resources, the “winner” being chosen randomly. Conditions for the spread of an initially rare selfish allele and the optimal resource allocation corresponding to the evolutionarily stable strategy, derived for species with n-seeded fruits, are in accordance with expectations based on Hamilton’s inclusive fitness criteria. Competition between seeds is seen to be most intense when there are only two seeds, and decreases with increasing number of seeds, suggesting that two-seeded fruits would be rarer than one-seeded or many-seeded ones. Available data from a large number of plant species are consistent with this prediction of the model. Based on a talk given at the Haldane Centenary Symposium held on 6 November 1992 at Ahmedabad as part of the 58th Annual Meeting of the Indian Academy of Sciences.     

Rocky bottom fauna in arctic Kongsfjord (Svalbard) studied by means of suction sampling and photography

The bottom fauna (16–30 m depth) of Kongsfjord (Svalbard) was investigated by direct observation, a SCUBA-diver operated suction sampler (quantitative) and underwater photography (semi-quantitative). The fauna on horizontal surfaces showed low similarity to that on vertical faces and overhangs, and had larger species heterogeneity between sampling sites. This was due to sedimentation and ice-rafted pebbles and stones creating “soft-bottom habitats” on the rocky bottom. Suction sampling resulted in collection of 73 taxa, including some species usually regarded as “soft-bottom” inhabitants. Fewer species were observed on the photographs, demonstrating the selectivity of this technique, but underwater photography may be a useful “non-destructive” method for obtaining information about conspicuous epifaunal taxa. Accepted: 18 July 2000     

Pyramid power: Principal cells of the hippocampus unite!

Electrical transmission in the mammalian brain is now well established. A new study by Thomson and colleagues elegantly demonstrates coupling between CA1 hippocampal pyramidal cells, which is far more common than previously supposed. Although the history of coupling is extensive, doubt, predjudice, and technical issues long kept it from wide acceptance. Here “spikelets” or “fast prepotentials” are found when two cells are coupled and in this situation result from electrical transmission of impulses from one coupled cell to the other. Interesting questions remain as to whether connexin or pannexin gap junctions serve as the molecular substrate of transmission, and the role of electrical transmission in hippocampal physiology is uncertain. Increased coupling could well contribute to the known tendency of the hippocampus to exhibit seizure activity.     

Phase change-related variations of dome shape in Eucalyptus urophylla × Eucalyptus grandis shoot apical meristems

Shoot apical meristem (SAM) domes derived from five different outdoor and in vitro sources of juvenile and mature Eucalyptus urophylla × Eucalyptus grandis akin genotypes were compared. Overall measurements of SAM dome height H and diameter D ranged from 2 to 35 μm and 20 to 80 μm, with significant differences according to the various physiological origins of plant material investigated. SAM domes from the mature trees “Mat” were taller than those from the rejuvenated ministock plants “Rej”; from the in vitro microcuttings “IVM” of the same clone and also from the in vitro juvenile seedlings “IVJ”, whereas outdoor seedlings “Juv” exhibited intermediate SAM dome height. SAM domes from the rejuvenated material “Rej”, from the in vitro mature “IVM” and juvenile “IVJ” origins were also narrower than those from the outdoor seedlings “Juv” and to lesser extent than those from the mature trees “Mat”. Overall, the mature source “Mat” displayed bigger and somehow sharper hemispherical domes than those from “Rej” and “Juv”, physiologically more juvenile, or those from the in vitro origins “IVM” and “IVJ” which looked flatter and smaller. SAM dome height, diameter D and H/D values varied also significantly according to the plastochron. More specifically, H, D, and H/D SAM differences between the five origins were not significant during the early plastochron phase corresponding to leaf initiation, to become more salient as leaf structures started to elongate and to differentiate. This was particularly obvious for mature tree “Mat” SAM dome shapes which showed at this stage much higher H/D values than the other SAM sources. A shape index S used for characterizing more accurately dome shape confirmed these trends. These observations provide additional arguments to the view that juvenility in trees becomes more and more time- and shoot-tip restricted as ageing increases in the course of time during the ontogenetical process and could be ultimately confined to the most organogenic phase of SAM, from which shoot characteristics derive.     

Reversal of Postischemic Hypoperfusion by Tempol: Endothelial Signal Transduction Mechanism

This report entails in vivo and in vitro studies concerned with free radical species involved in brain ischemia. The participation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in the early manifestation of cerebral ischemia/reperfusion was investigated in gerbils exposed to transient global ischemia using 4-OH-2,2,6,6-Tetramethylpiperidine-1-oxyl (TPL), a well-known antioxidant. TPL treatment reversed cerebral postischemic hypoperfusion and tissue edema in these animals. The findings are consistent with ROS/RNS participation in tissue injury and the reduction of cerebromicrovascular blood flow (CBF) during postischemic recirculation. The activation/deactivation of signal transduction pathway by oxidation/antioxidation [i.e., using hydrogen peroxide (H₂O₂)/TPL] was evaluated in cultured human brain endothelial cells (HBEC) to assess the involvement of endothelial-dependent mechanisms. The data showed that H₂O₂ activates various “stress” kinases and vasodilalator-stimulated phosphoprotein (VASP); activation of this pathway was reduced by inhibitors of Rho- or IP-3 kinases, as well as TPL. H₂O₂ also induced cytoskeleton (actin) rearrangements in HBEC; this effect was prevented by inhibitors of Rho/IP3 kinase or TPL. The observed activation/deactivation of H₂O₂-induced “stress” kinase is in agreement with the reported capacity of ROS/RNS to stimulate the oxidative signal transduction pathway. The noted TPL reduction of H₂O₂-induced phosphorylation of kinase strongly suggests that the beneficial effect of TPL implicates the stress signal transduction pathway. This may represent a mechanism for the cerebral postischemic manifestations observed by in vivo experiments.     

Assessment of aphid colonies by hoverflies. III Pea aphids andEpisyrphus balteatus (de Geer) (Diptera: Syrphidae)

The syrphid flyEpisyrphus balteatus (de Geer) migrating from maple trees to leguminous plants in mid-April, assesses the qualitative and quantitative value of pea aphid colonies for securing successful development of her offspring. She selects young and “promising” pea aphid colonies of small size. This generally agrees with the “buy-futures” ovipositional tactic the syrphid fly adopts when it utilizes the maple aphids. The advantage of a “buy-futures” ovipositional tactic found in many syrphid species is discussed in comparison with other aphidophagous insects.     

“Bioshrouding”—a novel approach for securing reactive mineral tailings

A novel technique (“bioshrouding”) for safeguarding highly reactive sulfidic mineral tailings deposits is proposed. In this, freshly milled wastes are colonised with ferric iron-reducing heterotrophic acidophilic bacteria that form biofilms on reactive mineral surfaces, thereby preventing or minimising colonisation by iron sulfide-oxidising chemolithotrophs such as Acidithiobacillus ferrooxidans and Leptospirillum spp. Data from initial experiments showed that dissolution of pyrite could be reduced by between 57 and 75% by “bioshrouding” the mineral with three different species of heterotrophic acidophiles (Acidiphilium, Acidocella and Acidobacterium spp.), under conditions that were conducive to microbial oxidative dissolution of the iron sulfide.     

“Not <Emphasis Type="Italic">Here</Emphasis>”: Making the Spaces and Subjects of “Global Health” in Botswana

This essay argues that what makes “global health” “global” has more to do with configurations of space and time, and the claims to expertise and moral stances these configurations make possible, than with the geographical distribution of medical experts or the universal, if also uneven, distribution of threats to health. Drawing on a study of public–private partnerships supporting Botswana’s HIV/AIDS treatment program, this essay demonstrates ethnographically the processes by which “global health” and its quintessential spaces, namely “resource-limited” or “resource-poor settings,” are constituted, reinforced, and contested in the context of medical education and medical practice in Botswana’s largest hospital. Using Silverstein’s work on orders of indexicality, I argue that the terms of “global health” are best understood as chronotopic, and demonstrate how actors orient themselves and others spatio-temporally, morally, and professionally by using or refuting those terms. I conclude by arguing that taking “global health” on its own terms obscures the powerful forces by which it becomes intelligible. At stake are the frames within which medical anthropologists understand their objects of study, as well as the potential for the spaces of “global health” intervention to expand ever outward as American medical personnel attempt to calibrate their experiences to their expectations.     

Molecular mechanisms of transformation of SkQ mitotropic quinones and the search for new approaches to creation of selective free radical traps

Features of the mechanism of action of positively charged benzoquinone derivatives (SkQ), which are the analogs of coenzyme Q (I), plastoquinone (II), and tocopherol (III), are discussed. It is usually considered that the main target of these compounds is mitochondria, where they accumulate due to the positive charge of the molecule. In the present work, it is shown with model systems that the reduced forms of compounds (I–III) under certain conditions can transform into electrically neutral cyclic zwitterions, which theoretically can escape from the matrix of energized mitochondria against the concentration gradient. A weak uncoupling effect of molecules I–III has been found on mitochondria. Its existence is in agreement with the abovementioned transformation of positively charged hydroquinones of type Ia–IIIa into electrically neutral molecules. The data obtained with model systems suggest that the target of SkQ hydroquinones as free radical traps may be not only mitochondria but also biochemical systems of the cytoplasm. Due to the presence of a large number of reactive oxygen species (ROS)-dependent signal systems in a cell, the functioning of cytoplasmic systems might be disturbed under the action of antioxidants. The problem of selective effect of antioxidants is discussed in detail in the present work, and a functional diagram of selective decrease of the “background level” of ROS based on differences in the intensity of background and “signal” ROS fluxes is considered.