Patologias na Superestrutura da Ferrovia Balastrada

Nesta dissertação de Mestrado, pretende-se contribuir para o conhecimento no âmbito das patologias da ferrovia, nomeadamente no que se refere a patologias em carril, balastro, travessas e elementos de fixação, tendo sido coletado neste trabalho as mais variadas patologias da ferrovia balastrada bem como a sua catalogação socioeconómica, permitindo com essa enumeração tomadas de decisão coerentes e assertivas no que respeita a recomendações a efetuar tanto como diagnostico como para manutenção. O trabalho inicia-se por uma introdução relativa ao aparecimento da ferrovia num contexto internacional, particularizando posteriormente o caso de Portugal até ao estado da arte atual, com um pequeno desenvolvimento a nível socie-económico com as grandes obras e projetos para os próximos anos. Para além da síntese de conhecimentos referida, apresentou-se um pouco da atualidade ferroviária de alguns países com relevância, quer por associação fronteiriça quer por desenvolvimento tecnológico. Apresenta-se brevemente os componentes mais importantes da ferrovia balastrada com especial destaque para os elementos da superestrutura de via, nos quais se engloba o carril, as travessas, os elementos de fixação e o balastro. Por fim esta dissertação apresenta um trabalho exaustivo na recolha e investigação das várias patologias associadas ao carril, as travessas, aos elementos de fixação e ao balastro, bem como o sistema de código, recomendações e correções associadas, fornecendo assim uma fácil interpretação do tipo de patologia e defeitos associados ao desenvolvimento desses fenómenos.

Introdução, estabelecimento e adaptação de Bradirrizóbios simbiontes da soja em a solos brasileiros.

Rizóbios microssimbiontes da soja; Introdução de estirpes nos solos brasileiros; Adaptação das estirpes de B. japonicum / B. elkanii aos solos brasileiros; Competitividade das estirpes de B elkanii SEMIA 587 e 29 W; Competitividade das estirpes do sorogrupo SEMIA 566 de B. japonicum; Variabilidade nas estirpes de Bradyrhizobium após a introdução nos solos brasileiros; Transferência horizontal de genes entre estirpes inoculantes e rizóbios indígenas ou naturalizados nos solos brasileiros.

Of Structural Denial: A Narratological Study of the Structural Disintegration of the Novel Form

If an opening to the argument of this dissertation is of imperative necessity, one might tentatively begin with Herbert Quain, born in Roscommon, Ireland, author of the novels The God of the Labyrinth (1933) and April March (1936), the short-story collection Statements (1939), and the play The Secret Mirror (undated). To a certain extent, this idiosyncratic Irish author, who hailed from the ancient province of Connacht, may be regarded as a forerunner of the type of novels which will be considered in this dissertation. Quain was, after all, the unconscious creator of one of the first structurally disintegrated novels in the history of western literature, April March. His first novel, The God of the Labyrinth, also exhibits elements which are characteristic of structurally disintegrated fiction, for it provides the reader with two possible solutions to a mysterious crime. As a matter of fact, one might suggest that Quain’s debut novel offers the reader the possibility to ignore the solution to the crime and carry on living his or her readerly life, turning a blind eye to the novel itself. It may hence be argued that Quain’s first novel is in fact a compound of three different novels. It is self-evident that the structure of Quain’s oeuvre is of an experimental nature, combining geometrical precision with authorial innovation, and one finds in it a higher consideration for formal defiance than for the text itself. In other words, the means of expression are the concern of the author and not, interestingly, the textual content. April March, for example, is a novel which regresses back into itself, its first chapter focussing on an evening which is preceded by three possible evenings which, in turn, are each preceded by three other, dissimilar, possible evenings. It is a novel of backward-movement, and it is due to this process of branching regression that April March contains within itself at least nine possible novels. Structure, therefore, paradoxically controls the text, for it allows the text to expand or contract under its formal limitations. In other words, the formal aspects of the novel, usually associated with the restrictive device of a superior design, contribute to a liberation of the novel’s discourse. It is paradoxical only in the sense that the idea of structure necessarily entails the fixation of a narrative skeleton that determines how plot and discourse interact, something which Quain flouts for the purposes of innovation. In this sense, April March’s convoluted structure allows for multiple readings and interpretations of the same text, consciously germinating narratives within itself, producing different texts from a single, unique source. Thus, text and means of expression are bonded by a structural design that, rather than limiting, liberates the text of the novel.

Minimal invasive surgery for coronoid fracture: technical note.

Operative treatment of coronoid fracture often requires a large dissection of soft tissue, resulting in elbow stiffness and functional limitation. The authors present a minimal invasive, safe technique, useful in the case of isolated coronoid fracture associated with elbow dislocation. This technique does not require soft tissue dissection and allows an early unlimited resumption of sports activities.

Evolutionary switch and genetic convergence on rbcL following the evolution of C4 photosynthesis.

Rubisco is responsible for the fixation of CO2 into organic compounds through photosynthesis and thus has a great agronomic importance. It is well established that this enzyme suffers from a slow catalysis, and its low specificity results into photorespiration, which is considered as an energy waste for the plant. However, natural variations exist, and some Rubisco lineages, such as in C4 plants, exhibit higher catalytic efficiencies coupled to lower specificities. These C4 kinetics could have evolved as an adaptation to the higher CO2 concentration present in C4 photosynthetic cells. In this study, using phylogenetic analyses on a large data set of C3 and C4 monocots, we showed that the rbcL gene, which encodes the large subunit of Rubisco, evolved under positive selection in independent C4 lineages. This confirms that selective pressures on Rubisco have been switched in C4 plants by the high CO2 environment prevailing in their photosynthetic cells. Eight rbcL codons evolving under positive selection in C4 clades were involved in parallel changes among the 23 independent monocot C4 lineages included in this study. These amino acids are potentially responsible for the C4 kinetics, and their identification opens new roads for human-directed Rubisco engineering. The introgression of C4-like high-efficiency Rubisco would strongly enhance C3 crop yields in the future CO2-enriched atmosphere.

Les prix des médicaments génériques

Die Kosten für Generika werden von der gesetzlichen Krankenversicherung übernommen, wenn sie die Bedingungen erfüllen, die das Bundesgesetz über die Krankenversicherung (KVG) und dessen Verordnungen vorgeben. Zu diesen Bedingungen gehören die Festsetzung eines Fabrikationspreises und die Festsetzung eines Maximalverkaufspreises. Diese Preise werden dann regelmässig über mehrere Jahre hinweg überprüft. Mehrere Revisionen der genannten Regelungen führten zu niedrigeren Preisen für Generika. Diese Preise sind allerdings umstritten, da sie immer noch höher sind als in den europäischen Nachbarländern. Der Beitrag beleuchtet die Regelungen des KVG für Generika. (sk) Les médicaments génériques sont pris en charge par l'assurance-maladie obligatoire s'ils remplissent les conditions imposées par la LAMal et ses ordonnances. Parmi ces conditions, figure la fixation d'un prix de fabrique (PF) et d'un prix public (PP) maximums. Ces prix sont ensuite régulièrement réexaminés au fil des ans. Les révisions successives des ordonnances susmentionnées ont conduit à une diminution des prix des génériques en Suisse. Leurs prix demeurent cependant controversés car ils sont globalement plus élevés que dans les pays européens voisins. L'article expose les règles LAMal applicables aux médicaments génériques.

Effect of biogeographic history on population vulnerability in European amphibians.

The genetic diversity of populations, which contributes greatly to their adaptive potential, is negatively affected by anthropogenic habitat fragmentation and destruction. However, continental-scale losses of genetic diversity also resulted from the population expansions that followed the end of the last glaciation, an element that is rarely considered in a conservation context. We addressed this issue in a meta-analysis in which we compared the spatial patterns of vulnerability of 18 widespread European amphibians in light of phylogeographic histories (glacial refugia and postglacial routes) and anthropogenic disturbances. Conservation statuses significantly worsened with distances from refugia, particularly in the context of industrial agriculture; human population density also had a negative effect. These findings suggest that features associated with the loss of genetic diversity in post-glacial amphibian populations (such as enhanced fixation load or depressed adaptive potential) may increase their susceptibility to current threats (e.g., habitat fragmentation and pesticide use). We propose that the phylogeographic status of populations (i.e., refugial vs. post-glacial) should be considered in conservation assessments for regional and national red lists.

丹桂籍Dan gui ji.Collection de traités taoïstes.

Contient : I太上感應篇Tai shang gan ying pian.Le Tai shang gan ying pian ; II文昌帝君陰騭文Wen chang di jun yin zhi wen.Traité de la fixation mystérieuse, par le dieu de la Littérature ; III關夫子覺世眞經Guan fu zi jue shi zhen jing.Le livre sacré de l'éveil du monde, de Guan fu zi ; IV關聖帝君降筆眞經Guan sheng di jun jiang bi zhen jing.Livre sacré écrit par le dieu de la Guerre ; V關聖帝君顯應戒士文Guan sheng di jun xian ying jie shi wen.Conseils aux lettrés, traité par le dieu de la Guerre ; VI東嶽聖帝垂訓Dong yue sheng di chui xun.Instructions du dieu du Dong yue ; VII呂純陽祖師勸世戒食牛犬Lü chun yang zu shi quan shi jie shi niu quan.Défense de manger le bœuf et le chien, traité par Lü Chun yang ; VIII文昌孝經Wen chang xiao jing.Livre sacré de la piété filiale, par Wen chang ; IX蕉窓十則Jiao chuang shi ze.Les dix commandements de Jiao tchhoang ; X功過格纂要Gong ge ge zuan yao.Éléments des règles du mérite et du péché ; XI桂香殿功過格Gui xiang dian gong ge ge.Règles du mérite et du péché, de la salle Gui xiang ; XII靈驗記Ling yan ji.Exemples miraculeux ; XIII文昌帝君降乩惜字功罪例Wen chang di jun jiang ji xi zi gong zui li.Règlement du mérite et du péché, relativement au respect des caractères d'écriture ; donné par le dieu de la Littérature ; XIV, livre préliminaire募刊疏引Mu kan su yin.Rapport et introduction sur la gravure de l'ouvrage ; XV, livre préliminaire婁東善書目錄.Lou dong shan shu mu lu.Liste d'ouvrages recommandés, dressée à Lou dong ; XVI, livre préliminaire文昌帝君丹桂籍靈驗記 。續記.Wen chang di jun dan gui ji ling yan ji. Xu ji.Notice des miracles dus au Dan gui ji du dieu delà Littérature, partie principale et suite ; XVII, livre préliminaire顏廷表先生傳.Yan ting biao xian sheng zhuan.Vie de Yan Ting biao ; XVIII, livre préliminaire顏雲麓先生傳.Yan yun lu xian sheng zhuan.Vie de Yan Yun lu ; XIX, livre préliminaire丹桂籍奉行心法.Dan gui ji feng xing xin fa.Préceptes pour pratiquer les règles du Dan gui ji ; XX, livre préliminaire文昌帝君降筆記.Wen chang di jun jiang bi ji.Notice dictée parle dieu de la Littérature ; XXI, livre préliminaire玉皇寶號.Yu huang bao hao.Les noms précieux de Yu huang ; XXII, livres 1-4九天開化主宰元皇司錄宏仁文昌帝君陰隲文註案Jiu tian kai hua zhu zai yuan huang si lu hong ren wen chang di jun yin zhi wen zhu an.Traité de la fixation mystérieuse, par le dieu de la Littérature ; avec commentaires et exemples ; XXIII, livre final文昌帝君救刧寶章Wen chang di jun jiu jie bao zhang.Précieux articles du dieu de la Littérature pour le salut du monde ; XXIV, livre final梓潼帝君降筆戒士子文Zi tong di jun jiang bi jie shi zi wen.Conseils aux lettrés, deux traités par le dieu de la Littérature ; XXV, livre final文昌帝君勸孝文Wen chang di jun quan xiao wen.Traité pour conseiller la piété filiale, par le dieu de la Littérature ; XXVI, livre final玉中書勸孝歌Yu zhong shu quan xiao ge.Chanson pour conseiller la piété filiale ; XXVII, livre final圓明鬥母天尊勸世文.Yuan ming dou mu tian zun quan shi wen.Conseils au monde, traité de la déesse Yuan ming dou mu ; XXVIII, livre final俞淨意先生遇竈神記.Yu jing yi xian sheng yu zao shen ji.Entrevue de Yu Jing yi avec l'esprit du Foyer ; XXIX, livre final袁了凡先生四訓 。立命之學.Yuan liao fan xian sheng si xun. Li ming zhi xue.Quatre exhortations de Yuan Liao fan. Première section : Science de la direction de la vie ; XXX, livre final積善之方Ji shan zhi fang.Deuxième section : Recette pour accumuler les bonnes actions ; XXXI, livre final改過之法Gai ge zhi fa.Troisième section : Moyen de corriger les fautes ; XXXII, livre final謙德之效Qian le zhi xiao.Quatrième section : Manifestation d'humilité ; XXXIII, livre final佛母準提神咒Fo mu zhun ti shen zhou.Invocation de la mère du Bouddha ; XXXIV, livre final袁了凡先生勸喪文Yuan liao fan xian sheng quan sang wen.Traité de Yuan Liao fan sur les funérailles ; XXXV, livre final遏淫說E yin shuo.Traité contre l'impureté ; XXXVI, livre final行不費錢功德例Xing bu fei qian gong de li.Manière d'obtenir des mérites sans dépenser d'argent

丹桂籍Dan gui ji.Collection de traités taoïstes.

Contient : I太上感應篇Tai shang gan ying pian.Le Tai shang gan ying pian ; II文昌帝君陰騭文Wen chang di jun yin zhi wen.Traité de la fixation mystérieuse, par le dieu de la Littérature ; III關夫子覺世眞經Guan fu zi jue shi zhen jing.Le livre sacré de l'éveil du monde, de Guan fu zi ; IV關聖帝君降筆眞經Guan sheng di jun jiang bi zhen jing.Livre sacré écrit par le dieu de la Guerre ; V關聖帝君顯應戒士文Guan sheng di jun xian ying jie shi wen.Conseils aux lettrés, traité par le dieu de la Guerre ; VI東嶽聖帝垂訓Dong yue sheng di chui xun.Instructions du dieu du Dong yue ; VII呂純陽祖師勸世戒食牛犬Lü chun yang zu shi quan shi jie shi niu quan.Défense de manger le bœuf et le chien, traité par Lü Chun yang ; VIII文昌孝經Wen chang xiao jing.Livre sacré de la piété filiale, par Wen chang ; IX蕉窓十則Jiao chuang shi ze.Les dix commandements de Jiao tchhoang ; X功過格纂要Gong ge ge zuan yao.Éléments des règles du mérite et du péché ; XI桂香殿功過格Gui xiang dian gong ge ge.Règles du mérite et du péché, de la salle Gui xiang ; XII靈驗記Ling yan ji.Exemples miraculeux ; XIII文昌帝君降乩惜字功罪例Wen chang di jun jiang ji xi zi gong zui li.Règlement du mérite et du péché, relativement au respect des caractères d'écriture ; donné par le dieu de la Littérature ; XIV, livre préliminaire募刊疏引Mu kan su yin.Rapport et introduction sur la gravure de l'ouvrage ; XV, livre préliminaire婁東善書目錄.Lou dong shan shu mu lu.Liste d'ouvrages recommandés, dressée à Lou dong ; XVI, livre préliminaire文昌帝君丹桂籍靈驗記 。續記.Wen chang di jun dan gui ji ling yan ji. Xu ji.Notice des miracles dus au Dan gui ji du dieu delà Littérature, partie principale et suite ; XVII, livre préliminaire顏廷表先生傳.Yan ting biao xian sheng zhuan.Vie de Yan Ting biao ; XVIII, livre préliminaire顏雲麓先生傳.Yan yun lu xian sheng zhuan.Vie de Yan Yun lu ; XIX, livre préliminaire丹桂籍奉行心法.Dan gui ji feng xing xin fa.Préceptes pour pratiquer les règles du Dan gui ji ; XX, livre préliminaire文昌帝君降筆記.Wen chang di jun jiang bi ji.Notice dictée parle dieu de la Littérature ; XXI, livre préliminaire玉皇寶號.Yu huang bao hao.Les noms précieux de Yu huang ; XXII, livres 1-4九天開化主宰元皇司錄宏仁文昌帝君陰隲文註案Jiu tian kai hua zhu zai yuan huang si lu hong ren wen chang di jun yin zhi wen zhu an.Traité de la fixation mystérieuse, par le dieu de la Littérature ; avec commentaires et exemples ; XXIII, livre final文昌帝君救刧寶章Wen chang di jun jiu jie bao zhang.Précieux articles du dieu de la Littérature pour le salut du monde ; XXIV, livre final梓潼帝君降筆戒士子文Zi tong di jun jiang bi jie shi zi wen.Conseils aux lettrés, deux traités par le dieu de la Littérature ; XXV, livre final文昌帝君勸孝文Wen chang di jun quan xiao wen.Traité pour conseiller la piété filiale, par le dieu de la Littérature ; XXVI, livre final玉中書勸孝歌Yu zhong shu quan xiao ge.Chanson pour conseiller la piété filiale ; XXVII, livre final圓明鬥母天尊勸世文.Yuan ming dou mu tian zun quan shi wen.Conseils au monde, traité de la déesse Yuan ming dou mu ; XXVIII, livre final俞淨意先生遇竈神記.Yu jing yi xian sheng yu zao shen ji.Entrevue de Yu Jing yi avec l'esprit du Foyer ; XXIX, livre final袁了凡先生四訓 。立命之學.Yuan liao fan xian sheng si xun. Li ming zhi xue.Quatre exhortations de Yuan Liao fan. Première section : Science de la direction de la vie ; XXX, livre final積善之方Ji shan zhi fang.Deuxième section : Recette pour accumuler les bonnes actions ; XXXI, livre final改過之法Gai ge zhi fa.Troisième section : Moyen de corriger les fautes ; XXXII, livre final謙德之效Qian le zhi xiao.Quatrième section : Manifestation d'humilité ; XXXIII, livre final佛母準提神咒Fo mu zhun ti shen zhou.Invocation de la mère du Bouddha ; XXXIV, livre final袁了凡先生勸喪文Yuan liao fan xian sheng quan sang wen.Traité de Yuan Liao fan sur les funérailles ; XXXV, livre final遏淫說E yin shuo.Traité contre l'impureté ; XXXVI, livre final行不費錢功德例Xing bu fei qian gong de li.Manière d'obtenir des mérites sans dépenser d'argent

An investigation of ethylene inhibition of growth in etiolated Avena sativa coleoptiles /

Growth rates of etiolated Avena sativa coleoptiles in pH 7.0 buffered medium are stimulated in a synergistic manner by IAA and 320 ~l/l carbon dioxide. The suggestion that carbon dioxide stimulated growth involves dark fixation is supported by the ability of 1 mM malate to replace carbon dioxide, with neither factor able to stimulate growth in the presence of the other (Bown, Dymock and Aung, 1974). The regulation of Avena coleoptile growth by ethylene has been investigated in the light of this data and the well documented antagonism between carbon dioxide and ethylene in the regulation of developmental processes. The influence of various permutations of ethylene, IAA, carbon dioxide and malate on the rates of growth, l4c-bicarbonate incorporation, l4C-bicarbonate fixation, and malate decarboxylation have been investigated. In the presence of 320 ~l/l carbon dioxide, 10.8 ~l/l ethylene inhibited growth both in the absence and presence of 20 ~M IAA with inhibition times, of 8-10 and 12-13 minutes respectively. In contrast ethylene inhibition of growth was not significant in the absence of growth stimulation by CO2 or 1 mM malate, and the normal growth increases in response to CO2 and malate were blocked by the simultaneous application of ethylene. The rates of incorporation and dark fixation of l4C-bicerbonate were not measurably. influenced by ethylene, IAA or malate, either prior to or during the changes in growth ,ates induced by these agents. The data does not support the hypothesis that ethylene inhibition of growth results from an inhibition of dark fixation, but suggests that ethylene may inhibit a process which is subsequent to fixation.

An investigation into differences between indoleacetic acid and fusicoccin in their influence on RNA synthesis, protein synthesis and growth in Avena coleoptile tissue

Growth stimulation of Avena coleoptile tissue by indoleacetic acid (IAA) and fusicoccin (FC) was compared by measuring both their influence on RNA and protein synthesis during IAA or FC stimulated growth. FC stimulated growth more than IAA during the initial four hour exposure, after which the growth rate gradually declined to the control rate. FC, but not IAA, increased the uptake of 3H-Ieucine into tissue and the specific radioactivity of extracted protein. Cycloheximide inhibited the incorporation of 3H-Ieucine into protein by approximately 60% to 70% in all cases. In the presence of cycloheximide 3H-radioactivity accumulated in FC-treated tissue, whereas IAA did not seem to influence 3H-accumulation. These results suggest that FC stimulated leucine uptake into the tissue and that increased specific activity of coleoptile protein is due to increased leucine uptake, not an increased rate of protein synthesis. There was no measurable influence of IAA and/or FC on RNA and protein synthesis during the initial hours of a growth stimulation. Inhibitors of RNA and protein synthesis, actinomycin D and cycloheximide, respectively, severely inhibited IAA enhanced growth but only partially inhibited FC stimulated growth. The data are consistent with suggestions that a rapidly turning over protein participates in IAA stimulated growth, and that a continual synthesis of RNA and proteins is an absolute requirement for a long term growth response to IAA. On the contrary, FC-stimulated growth exhibited less dependency on the transcription and translation processes. The data are consistent with proposals suggesting different sites of action for FC and IAA stimulated growth. l?hen compared to CO2-free air, CO2 at 300 ppm had no significant influence on coleoptile growth and protein synthesis in the presence or absence of lAA or FC. Also, I mM malate, pH 6.0 did not influence growth of coleoptiles in the presence or absence of lAA. This result was obtained despite reports indicating that 300 ppm CO2 or I mM malate stimulates growth and protein synthesis. This lack of difference between CO2-treated and untreated tissue could indicate either that the interstitial space CO2 concentration is not actually different in the two treatments due to significant endogenous respiratory CO2 or else the data would suggest a very loose coupling between dark CO2 fixation and growth. IAA stimulated the in vivo fixation of 14c-bicarbonate (NaHI4c03) by about 25% and the addition of cycloheximide caused an inhibition of bicarbonate fixation within 30 min. Cycloheximide has also been reported to inhibit IAA-stimulated H+ excretion. These data are consistent with the acid growth theory and suggest that lAA stimulated growth involves dark CO2 fixation. The roles of dark CO2 fixation in lAA-stimulated growth are discussed.

Molecular cloning restriction enzyme analysis, bovine adenovirus type 2 genome

Adenoviruses are non-enveloped icosahedral-shaped particles which possess a double-stranded DNA genome. Currently, nearly 100 serotypes of adenoviruses have been identified, 48 of which are of human origin. Bovine adenoviruses (BAVs), causing both mild respiratory and/or enteral diseases in cattle, have been reported in many countries all over the world. Currently, nine serotypes of SAVs have been isolated which have been placed into two subgroups based on a number of characteristics which include complement fixation tests as well as the ability to replicate in various cell lines. Bovine adenovirus type 2 (BAV2), belonging to subgroup I, is able to cause pneumonia as well as pneumonic-like symptoms in calves. In this study, the genome of BAV2 (strain No. 19) was subcloned into the plasmid vector pUC19. In total, 16 plasmids were constructed; three carry internal San fragments (spanning 3.1 to 65.2% ), and 10 carry internal Pstl fragments (spanning 4.9 to 97.4%), of the viral genome. Each of these plasmids was analyzed using twelve restriction endonucleases; BamHI, CiaI, EcoRl, HiOOlll, Kpnl, Noll, NS(N, Ps~, Pvul, Saj, Xbal, and Xhol. Terminal end fragments were also cloned and analyzed, sUbsequent to the removal of the 5' terminal protein, in the form of 2 BamHI B fragments, cloned in opposite orientations (spanning 0 to 18.1°k), and one Pstll fragment (spanning 97.4 to 1000/0). These cloned fragments, along with two other plasmids previously constructed carrying internal EcoRI fragments (spanning 20.6 to 90.5%), were then used to construct a detailed physical restriction map using the twelve restriction endonucleases, as well as to estimate the size of the genome for BAV2(32.5 Kbp). The DNA sequences of the early region 1 (E1) and hexon-associated gene (protein IX) have also been determined. The amino acid sequences of four open reading frames (ORFs) have been compared to those of the E1 proteins and protein IX from other Ads.

Sex chromosome translocation and speciation : a Drosophila genetic model

Although exceptions may be readily identified, two generalizations concerning genetic differences among species may be drawn from the available allozyme and chromosome data. First, structural gene differences among species vary widely. In many cases, species pairs do not differ more than intraspecific populations. This suggests that either very few or no gene substitutions are required to produce barriers to reproduction (Avise 1976). Second, chromosome form and/or number differs among even closely related species (White 1963; 1978; Fredga 1977; Wright 1970). Many of the observed chromosomal differences involve translocational rearrangements; these produce severe fitness depression in heterozygotes and were, thus, long considered unlikely candidates for the fixation required of genetic changes leading to speciation (Wright 1977). Nonetheless, the fact that species differences are frequently translocational argues convincingly for their fixation despite prejudices to the contrary. Haldane's rule states that in the F of interspecific crosses, the heterogametic sex is absent or sterile in the preponderance of cases (Haldane 1932). This rule definitely applies in the genus Dr°sophila (Ehrman 1962). Sex chromosome translocations do not impose a fitness depression as severe as that imposed by autosomal translocations, and X-Y translocations may account for Haldane's rule (Haldane 1932). Consequently a study of the fit ness parameters of an X·yL and a yS chromosome in Drosophila melanogaster populations was initiated by Tracey (1972). Preliminary results suggested that x.yL//YSmales enjoyed a mating advantage with X·yL//X·yL females, that this advantage was frequency dependent, that the translocation produced sexual isolation and that interactions between the yL, yS and a yellow marker contributed to the observed isolation (Tracey and Espinet 1976; Espinet and Tracey 1976). Encouraged by the results of these prelimimary studies, further experiments were performed to clarify the genetic nature of the observed sexual isolation, S the reality of the y frequency dependent fitness .and the behavioural changes, if any, produced by the translocation. The results of this work are reported herein. Although the marker genes used in earlier studies, sparkling poliert an d yellow have both been found to affect activity,but only yellow effects asymmetric sexual isolation. In addition yellow effects isolation through an interaction with the T(X-y) chromosomes, yS also effects isolation, and translocational strains are isolated from those of normal karyotype in the absence of marker gene differences. When yS chromosomes are in competition with y chromosomes on an X.yL background, yS males are at a distinct advantage only when their frequency is less than 97%. The sex chromosome translocation alters the normal courtship pattern by the incorporation of circling between vibration and licking in the male repertoire. Finally a model of speciation base on the fixation of this sex chromosome translocation in a geographically isolated gene pool is proposed.

The influence of carbon dioxide on growth and metabolism of etiolated Avena sativa 1 coleoptiles

The influence of carbon dioxide on growth and protein synthesis of etiolated Avena coleoptiles was investigated. Evidence is presented that 0.03% carbon dioxide stimulated both these processes; and that carbon dioxide stimulated growth depends on carbon dioxide stimulated protein synthesis, In addition the evidence indicates that carbon dioxide stimulated growth is mediated by metabolism, and that carbon dioxide stimulates growth through a dark fixation process. Growth studies also demonstrated that IAA and carbon dioxide stimulated growth in a synergistic manner.