Using in vitro androgenesis serves as a unique opportunity to produce doubled haploid (DH) plants in many species. More benefits of this biological phenomenon have kept these methods in the focus of fundamental research and crop breeding for decades. In common wheat (Triticum aestivum L.), in vitro anther culture is one of the most frequently applied DH plant production methods. The efficiency of in vitro wheat anther culture is influenced by many factors, such as the genotype, growing conditions, collection time, pre-treatments, and compositions of media and culture conditions. According to some critical review, the genotype dependency, low efficiency and albinism are mentioned as limitations of application of the anther culture method. However, some research groups have made significant efforts to diminish the effects of these bottlenecks. Due to the improvements, a well-established in vitro anther culture method can be an efficient tool in modern wheat breeding programs.
The starting point of the study on the problems, dilemmas and hopes for effective implementation of revitalization projects in Polish cities was the conviction that revitalization is one of the processes affecting the development and changes in the spatial and functional fabric of cities. Revitalization is defined as a deliberate and purposeful process, the effect of which is to restore life in the dysfunctional and degraded parts of cities. Taking up such a topic required an answer to the question about the nature of revitalization and its aspects. The focus of the study was on the problems of revitalization that stem from the legal and socio-economic situation and the dilemmas faced by local government authorities of Polish cities. The introduction to these considerations is the brief outline of the revitalization of Polish cities in the period after World War II, while the conclusion deals with the fears and hopes related to revitalization activities that are presently initiated. The discussion takes into account the existing, critically assessed, legal regulations on revitalization.
The author argues in favor of a claim concerning a version of radical skepticism that he calls ‘dubitative’. Unlike the radical skepticism once described by Jan Woleński that consists in the skeptic’s total refraining from making any definite statements, ‘dubitative skepticism’ consists in the skeptic’s expression of his/her doubt as regards to whatever he/she is presented with, including his/her own putative statements. ‘Doubt’ equals ‘lack of having a justification’ for a given definitive statement. This attitude is incontrovertibly possible for both a relevant p and a not-p. But ‘doubt about having a justification for p’ is incompatible with ‘doubt about not having a justification for p’. Whatever choice is made in the end, it is contained in the skeptic’s actual statement to the effect that he/she has knowledge concerning something, i.e. a knowledge that concerns his/her state of mind plus the knowledge that he/she has expressed it in the statement itself (and so on, ad infinitum). This extirpates radicalism from the skepticism of a dubitative skeptic, who, as it appears, by no means denounces any commitment to making a statement or to having knowledge. The article closes with an appropriate formal argument expressed in standard terms.
The emergence of life on Earth and its almost infinite diversity, reflected by a myriad of living organisms, are among the dilemmas that have forever fascinated scientists and philosophers. Today, we are still not able to determine what exactly initiated the chain of events leading to the rise of life – the mechanism of replication of initial structures or perhaps the occurrence of first metabolic reactions. Further approximations of these issues shall probably constitute an overwhelming driving force for future development of life sciences.
In 16-18th century Poland there were few trials of blasphemy, including interferences into Church services or processions. the severe verdicts, capital punishment included, were rarely executed. The most frequently punished for an outrage against Catholic religious feelings were plebeians. No special attention was paid to the possible offences committed by noblemen and magnates. Thus, nothing happened to Erazm Otwinowski who in 1564 trampled on a monstrance torn out from a priest leading a procession. A Calvinist Marcin Kreza who also committed such an offence in 1580 went unpublished too. At the end of century Stefan Łowejko, who publicly manifested his atheism, was not even imprisoned. Although in 1785 a young magnate Henryk Niemirycz, who publicly profaned a host, was sentenced to death. He survived because he left the country. As it shows a coat of arms usually was a good protection against the administration of justice, even in denominational matters.