scholarly journals Production of hybrid potatoes: Are heterozygosity and ploidy levels important?

2019 ◽  
pp. 687-694
Author(s):  
Jane Muthoni ◽  
Hussein Shimelis ◽  
Rob Melis
Keyword(s):  
Genetic Basis ◽  
Potato Breeding ◽  
Allelic Diversity ◽  
Solanum Species ◽  
Ploidy Levels ◽  
Cultivated Potato ◽  
Tetraploid Level ◽  
Diploid Level ◽  
Do So

It has been proposed that maximizing heterosis for yield in potato may be achieved by maximizing heterozygosity and associated intra and interlocus interactions. Tetraploids offer more opportunities to create such interactions than diploids hence the general observations that tetraploids are higher yielding than diploids. Consequently, efforts have been made to increase heterozygosity in tetraploids by introgressing allelic diversity from other Solanum species into cultivated potato. However, conventional potato breeding is difficult because the cultivated potato is an autotetraploid with tetrasomic inheritance and it comprises highly heterozygous individuals which suffer inbreeding depression upon selfing; breeding at the tetraploid level is slow and less efficient than at diploid level. At the diploid level, it is possible to breed for and fix traits under recessive genetic control; it is nearly impossible to do so at the tetraploid level. There is also rapid response to selection due to greater variation in diploids than tetraploids. Consequently, there have been efforts to convert potato from an asexually propagated tetraploid crop into an inbred seed-propagated diploid; this is by production of inbred lines through selfing of the tetraploids to assemble desirable combinations of genes in the inbreds. These efforts are at the experimental stages and a lot of research needs to be done before they are confirmed. Because currently there is little experimental evidence to support superiority of the inbred seed-propagated diploid strategy, it appears the theory that heterosis for yield in potato may be achieved by maximizing heterozygosity and associated intra and interlocus interactions remain unchallenged; these interactions are more in tetraplods than in diploids. This paper therefore looks at genetic basis of yield heterosis in cultivated potato and the role of heterozygosity and ploidy level in production of hybrid potatoes.

GENETIC RELATIONSHIPS BETWEEN DIPLOIDS AND TETRAPLOIDS IN SERIES EUBARBATAE OF AVENA

1968 ◽  
Vol 10 (1) ◽  
pp. 68-81 ◽  
Author(s):  
Gideon Ladizinsky ◽  
Daniel Zohary
Keyword(s):  
Gene Flow ◽  
Genetic Relationships ◽  
Extreme Case ◽  
Meiotic Behavior ◽  
Ploidy Levels ◽  
Single Genome ◽  
In Series ◽  
Full Shift ◽  
Tetraploid Level ◽  
Diploid Level

Diploid (2n = 14) and tetraploid (2n = 28) entities in series Eubarbatae of the genus Avena have been found to be genetically closely linked and are regarded as a single polyploid complex. At both ploidy levels the various morphological types are interfertile. Diploids and tetraploids are largely sympatric in their distribution and converge considerably in their ranges of morphological variation. Contacts between diploids and tetraploids are common and blurred morphological boundaries characterize mixed populations.The possibility of gene flow between diploids and tetraploids has been indicated by the behavior of triploid F1 hybrids. Such hybrids have been found to be partially fertile. In their progeny a conspicuous restoration of fertility is apparent: numerous plants of the F2 generation have been stabilized around the tetraploid level, few around the diploid level. In contact areas, triploids can be regarded as efficient bridges of gene flow between the two ploidy levels.The range of variation found at the tetraploid level is fully explicable by the variation present in the diploid races. Tetraploids are therefore regarded to have had an inter-varietal origin, i.e. have evolved from a single genome. They apparently represent an extreme case of bivalentization, where a full shift from an autotetraploid to an allotetraploid meiotic behavior had occurred. Meiotic behavior of the F2 plants also indicate such origin.

A Re-Appraisal of the Role of Blood Coagulation and Platelets in the Generalized Shwartzman Phenomenon

1966 ◽  
Vol 15 (03/04) ◽  
pp. 519-538 ◽  
Author(s):  
J Levin ◽  
E Beck
Keyword(s):  
Blood Coagulation ◽  
The State ◽  
Coagulation System ◽  
Renal Lesions ◽  
Intravascular Coagulation ◽  
Renal Glomeruli ◽  
Coagulation Mechanism ◽  
Shwartzman Phenomenon ◽  
Do So

SummaryThe role of intravascular coagulation in the production of the generalized Shwartzman phenomenon has been evaluated. The administration of endotoxin to animals prepared with Thorotrast results in activation of the coagulation mechanism with the resultant deposition of fibrinoid material in the renal glomeruli. Anticoagulation prevents alterations in the state of the coagulation system and inhibits development of the renal lesions. Platelets are not primarily involved. Platelet antiserum produces similar lesions in animals prepared with Thorotrast, but appears to do so in a manner which does not significantly involve intravascular coagulation.The production of adrenal cortical hemorrhage, comparable to that seen in the Waterhouse-Friderichsen syndrome, following the administration of endotoxin to animals that had previously received ACTH does not require intravascular coagulation and may not be a manifestation of the generalized Shwartzman phenomenon.

Anti-Myelin Oligodendrocyte Glycoprotein Encephalomyelitis and Extensive Longitudinal Transverse Myelitis Associated with Compound Heterozygous NLRP3 Missense Mutations in a Young Child

2020 ◽  
Author(s):  
Deirdre O'Sullivan ◽  
Michael Moore ◽  
Susan Byrne ◽  
Andreas O. Reiff ◽  
Susanna Felsenstein
Keyword(s):  
Young Child ◽  
Genetic Basis ◽  
Transverse Myelitis ◽  
Acute Disseminated Encephalomyelitis ◽  
Myelin Oligodendrocyte Glycoprotein ◽  
Compound Heterozygous ◽  
Missense Mutations ◽  
Childhood Onset

AbstractAcute disseminated encephalomyelitis in association with extensive longitudinal transverse myelitis is reported in a young child with positive anti-myelin oligodendrocyte glycoprotein (MOG) antibody with heterozygous NLRP3 missense mutations; p.(Arg488Lys) and p.(Ser159Ile). This case may well present an exceptional coincidence, but may describe a yet unrecognized feature of the spectrum of childhood onset cryopyrinopathies that contribute to the understanding of the genetic basis for anti-MOG antibody positive encephalomyelitis. Based on this observation, a larger scale study investigating the role of NLRP3 and other inflammasomes in this entity would provide important pathophysiological insights and potentially novel avenues for treatment.

‘Wheels have been set in motion’: Geocentrism and Relativity in Tom Stoppard’s Rosencrantz and Guildenstern Are Dead

2018 ◽  
Author(s):  
Liliane Campos
Keyword(s):  
20Th Century ◽  
Film Adaptation ◽  
Frames Of Reference ◽  
Quantum Uncertainty ◽  
Galilean Relativity ◽  
Modern Physics ◽  
20Th Century Physics ◽  
Time Specific ◽  
Do So

By decentring our reading of Hamlet, Stoppard’s tragicomedy questions the legitimacy of centres and of stable frames of reference. So Liliane Campos examines how Stoppard plays with the physical and cosmological models he finds in Hamlet, particularly those of the wheel and the compass, and gives a new scientific depth to the fear that time is ‘out of joint’. In both his play and his own film adaptation, Stoppard’s rewriting gives a 20th-century twist to these metaphors, through references to relativity, indeterminacy, and the role of the observer. When they refer to the uncontrollable wheels of their fate, his characters no longer describe the destruction of order, but uncertainty about which order is at work, whether heliocentric or geocentric, random or tragic. When they express their loss of bearings, they do so through the thought experiments of modern physics, from Galilean relativity to quantum uncertainty, drawing our attention to shifting frames of reference. Much like Schrödinger’s cat, Stoppard’s Rosencrantz and Guildenstern are both dead and alive. As we observe their predicament, Campos argues, we are placed in the paradoxical position of the observer in 20th-century physics, and constantly reminded that our time-specific relation to the canon inevitably determines our interpretation.

Helping when desire is low: The role of Expectancy in helping

2020 ◽  
Author(s):  
Małgorzata Kossowska
Keyword(s):  
Experimental Studies ◽  
Helping Behavior ◽  
Perceived Effectiveness ◽  
Do So

One might assume that the desire to help (here described as Want) is the essential driver of helping declarations and/or behaviors. However, even if desire to help is low, helping behavior may still occur if the expectancy regarding the perceived effectiveness of helping is high. We tested these predictions in a set of three experimental studies. In all three, we measured the desire to help (Want) and the Expectancy that the aid would be impactful for the victim; in addition, we manipulated Expectancy in Study 3. In Studies 1 and 3, we measured the participants’ declaration to help while in Study 2, their helping behavior was examined. In all three studies, we used variations of the same story about a victim. The results supported our hypothesis. Thus, the studies help to tease apart the determinants of helping behavior under conditions of lowered desire to do so, an issue of great importance in public policymaking.

History and Transport Policy

Transfers ◽  
2014 ◽  
Vol 4 (1) ◽  
pp. 45-62 ◽  
Author(s):  
Ueli Haefeli ◽  
Fritz Kobi ◽  
Ulrich Seewer
Keyword(s):  
Knowledge Transfer ◽  
Transport Policy ◽  
Science And Policy ◽  
Direct Knowledge ◽  
Academic System ◽  
Decision Making Processes ◽  
Policy And Planning ◽  
Policy Solutions ◽  
Do So

Based on analysis of two case studies in the Canton of Bern, this article examines the question of knowledge transfer from history to transport policy and planning in the recent past in Switzerland. It shows that for several reasons, direct knowledge transfer did not occur. In particular, historians have seldom become actively involved in transport planning and policy discourses, probably partly because the academic system offers no incentive to do so. However, historical knowledge has certainly influenced decision-making processes indirectly, via personal reflection of the actors in the world of practice or through Switzerland's strongly developed modes of political participation. Because the potential for knowledge transfer to contribute to better policy solutions has not been fully utilized, we recommend strengthening the role of existing interfaces between science and policy.

Stative Morpheme In Shimakonde, An Anticausative Morpheme?

2017 ◽  
Vol 19 ◽  
pp. 343-376
Author(s):  
Ronaldo Rodrigues De Paula
Keyword(s):  
External Argument ◽  
Bantu Language ◽  
Northern Regions ◽  
Do So

Tis paper aims to describe the syntax of the constructions that present the verbal extensions {-ik-} and {-uk-} and their allomorphs in Shimakonde, a Bantu language classifed as P23 in the Guthrie classifcation (GUTHRIE 1967-71). Tis language is spoken in the northern regions of Mozambique and Tanzania. Tese verbal extensions are reported in literature under the labels of stative, impositive, pseudo-passive, neuter, and quasi-passive (DOKE, 1947; SATYO, 1985; MCHOMBO, 1993; DUBINSKY SIMANGO, 1996; BENTLEY KULEMEKA, 2001; LIPHOLA, 2001; NGUNGA, 2004; KHUMALO, 2009; LEACH, 2010; LANGA, 2013). Te addition of the {-ik-} or {-uk-} morphemes to the verb structure usually demotes or suppresses the external argument, turning a basically transitive predicate into an intransitive one. Tis paper aims to investigate in Shimakonde if alternations from a dyadic to a monadic predicate, through the use of one of the aforementioned morphemes, are instances of the phenomenon known in literature as causative/ anticausative alternation (HASPELMATH, 1987, 1993; LEVIN RAPPAPORT HOVAV, 1992, 1995; NAVES, 1998, 2005; VAN HOUT, 2004; OLIVEIRA, 2011; KALLULLI, 2007). In order to do so, I analyze the grammatical role of this morpheme with two Shimakonde native consultants from different Mozambique districts (Mocimboa da Praia and Montepuez). Te feldwork activities consisted of translations of sentences from Portuguese to Shimakonde, testing the grammaticality of the proposed sentences. In order to examine the data that were collected, I adopted the Alexiadou, Anagnostopoulou and Schäfer (2006) refnement of the verbal categories by Levin Rappaport Hovav (1992, 1995). One of the results obtained is that the verbal extensions display an atelic reading (giving rise to stative interpretation) or a telic reading (giving rise to anticausative or passive interpretation). To account for the different interpretations in these constructions, I propose distinct associations between Asp head and Voice head in accordance with Kratzer (1996), Pylkkänen (2002), van Hout (2004), and Oliveira (2010).

The Role of the Judiciary and Its Relationship to the Convention on the Rights of Persons with Disabilities

2018 ◽  
Author(s):  
Lisa Waddington
Keyword(s):  
Legal System ◽  
Amicus Curiae ◽  
Persons With Disabilities ◽  
Legal Duty ◽  
The Relationship ◽  
Do So

This chapter examines the role of the judiciary with regard to the Convention on the Rights of Persons with Disabilities (CRPD). It considers the relationship which the judiciary have or appear to perceive themselves as having with the CRPD and explores some of the factors seemingly prompting courts to refer to it. The first section reflects on: whether judges are able to choose to refer to the Convention or have a legal duty to do so; the significance of the fact that the CRPD is international law; and whether judges appear to see themselves merely as domestic actors, or as agents or trustees of the CRPD. The second section explores whether judges are referring to the CRPD in response to arguments raised before the court or doing so of their own volition. Also considered are the relevance of amicus curiae interventions; reasons for referral related to the domestic legal system; and the role of particularly engaged individuals.

Levinas as a Reader of Jewish Texts

2018 ◽  
pp. 442-458
Author(s):  
Ethan Kleinberg
Keyword(s):  
Reading Strategies ◽  
Related Issue ◽  
Written Texts ◽  
The Holocaust ◽  
Historical Moment ◽  
And Training ◽  
Do So

This article attempts to understand Levinas as a reader of Jewish texts, with particular attention paid to his Talmudic commentaries. To do so, the entangled relation between oral and written texts is explored; one must be able to properly “read” but also “write,” and there is the related issue of the methodology and training to be able to do so properly. Levinas offers commentary on each issue. Several interpretations of Talmudic texts and an important discussion of reading Scripture are analyzed in order to elucidate Levinas’s reading strategies, what this tells us about his relation to the larger tradition of Talmudic commentary, and Levinas’s particular historical moment, especially the role of the Holocaust for his approach to reading the Talmud and traditional texts.

scholarly journals Wider-community Segregation and the Effect of Neighbourhood Ethnic Diversity on Social Capital: An Investigation into Intra-Neighbourhood Trust in Great Britain and London

Sociology ◽  
2016 ◽  
Vol 51 (5) ◽  
pp. 1011-1033 ◽  
Author(s):  
James Laurence
Keyword(s):  
Social Capital ◽  
Great Britain ◽  
Ethnic Diversity ◽  
Linear Models ◽  
Critical Role ◽  
Hierarchical Linear Models ◽  
Negatively Associated ◽  
Community Segregation ◽  
Do So

Extensive research has demonstrated that neighbourhood ethnic diversity is negatively associated with intra-neighbourhood social capital. This study explores the role of segregation and integration in this relationship. To do so it applies three-level hierarchical linear models to two sets of data from across Great Britain and within London, and examines how segregation across the wider-community in which a neighbourhood is nested impacts trust amongst neighbours. This study replicates the increasingly ubiquitous finding that neighbourhood diversity is negatively associated with neighbour-trust. However, we demonstrate that this relationship is highly dependent on the level of segregation across the wider-community in which a neighbourhood is nested. Increasing neighbourhood diversity only negatively impacts neighbour-trust when nested in more segregated wider-communities. Individuals living in diverse neighbourhoods nested within integrated wider-communities experience no trust-penalty. These findings show that segregation plays a critical role in the neighbourhood diversity/trust relationship, and that its absence from the literature biases our understanding of how ethnic diversity affects social cohesion.

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