Arthur Rörsch - Academia.edu (original) (raw)

Papers by Arthur Rörsch

Arthur Rorsch, Pieterskerkhof 40c, 2311 ST Leiden, The Netherlands. MSc Degree in Chemical Engine... more Arthur Rorsch, Pieterskerkhof 40c, 2311 ST Leiden, The Netherlands. MSc Degree in Chemical Engineering Universiy of Delft, 1957. PhD Leiden University 1962 Researcher in molecular radiation biology 1957-1973, Professor of Molecular Genetics, Medical Faculty Leiden University, 1967-1997 Vice President of the Netherlands Organization of Aplied Research TNO, responsible for Nutrition, Public Health and Environmental Research, 1980-1995

Mutat Res Fundam Mol Mech Mut, 1972

Journal of General Microbiology, 1975

A procedure to enrich for auxotrophic and fermentation mutants of Agrobacterium turnefaciens is d... more A procedure to enrich for auxotrophic and fermentation mutants of Agrobacterium turnefaciens is described. The method is based on the amplification

Energy & Environment, 2005

This paper provides a literature study of the observations on temperature changes and the accumul... more This paper provides a literature study of the observations on temperature changes and the accumulation of carbon dioxide in the atmosphere. It investigates the cause-effect relationship between these parameters, and makes an alternative interpretation to that given by the UN Intergovernmental Panel on Climate Change (IPCC).

Energy & Environment, 2005

The flow of carbon dioxide through the atmosphere is a complex system because it consists of seve... more The flow of carbon dioxide through the atmosphere is a complex system because it consists of several cycles; e.g., through the biosphere which produces and consumes it, and through the Earth's water surfaces which absorb and emit it. These processes are dependent on temperature but their reactions to temperature have different signs. Temperature rise promotes both the consumption and the production of carbon dioxide by the biosphere but liberates carbon dioxide from water surfaces. This paper offers a comprehensive review of the behaviour of these processes. It considers these flows and assesses observations of the movement of carbon dioxide to and from the atmosphere. The disturbance of the natural cycle by current anthropogenic emissions is used as an instrument to throw light on what is actually happening to cause alteration to atmospheric carbon dioxide concentration. Also, these considerations are used in attempts to model the processes with mathematical equations derived from physics and biology. It...

Energy & Environment, Mar 1, 2005

The flow of carbon dioxide through the atmosphere is a complex system because it consists of seve... more The flow of carbon dioxide through the atmosphere is a complex system because it consists of several cycles; e.g., through the biosphere which produces and consumes it, and through the Earth's water surfaces which absorb and emit it. These processes are dependent on temperature but their reactions to temperature have different signs. Temperature rise promotes both the consumption and the production of carbon dioxide by the biosphere but liberates carbon dioxide from water surfaces. This paper offers a comprehensive review of the behaviour of these processes. It considers these flows and assesses observations of the movement of carbon dioxide to and from the atmosphere. The disturbance of the natural cycle by current anthropogenic emissions is used as an instrument to throw light on what is actually happening to cause alteration to atmospheric carbon dioxide concentration. Also, these considerations are used in attempts to model the processes with mathematical equations derived from physics and biology. It...

It is shown that a large plasmid in A. tumefaciens cells, called the TI-plasmid, besides being es... more It is shown that a large plasmid in A. tumefaciens cells, called the TI-plasmid, besides being essential for oncogenicity also determines: (1) the specificity and the activity of the enzyme-system for octopine or nopaline utilisation; (2) the synthesis of either octopine or nopaline in crown gall cells as well as the morphology of the tumors on Kalanchoe stems. A few A. tumefaciens strains give rise to tumors whose cells do not synthesise octopine or nopaline. This indicates that these compounds themselves are not essential for the tumorous nature of the plant cells. Roots induced by the hairy root disease bacteria of two A. rhizogenes strains tested do not contain nopaline or octopine. Although octopine or nopaline could also not be detected in normal tissues of Kalanchoe, teratomata and aberrant looking roots developing from tumors do contain the same type of guanidine derivative as present in the tumor from which they develop. This suggests that once synthesis of the unusual guan...

Journal of Bacteriology, 1973

Strains carrying either the polA1 or resA1 mutation are deficient in DNA polymerase I, and the po... more Strains carrying either the polA1 or resA1 mutation are deficient in DNA polymerase I, and the polA1 and resA1 mutations do not complement in merozygotes. The effect of these mutations in otherwise identical genetic backgrounds was studied: after ultraviolet irradiation both strains degrade their DNA more rapidly and more extensively than the wild-type strains. However, after X-ray irradiation the resA1 strain shows little DNA breakdown and repairs its single-strand breaks. In contrast, the polA1 strain degrades its DNA extensively, and single-strand breaks are not repaired. Moreover, the resA1 strain is capable of supporting the growth of a red − bacteriophage lambda, whereas the polA1 strain is not.

Journal of General Microbiology, 1977

A mutant of A. tumefaciens strain ~6~3 , carrying the R factor RP4, was able to transfer its TI p... more A mutant of A. tumefaciens strain ~6~3 , carrying the R factor RP4, was able to transfer its TI plasmid to various avirulent Agrobacterium strains and to a strain of Rhizobium. Strains carrying the TI(~6s3) plasmid were selected by their ability to utilize octopine. The isolates were able to induce tumours and exclude phage API. The tumours induced on Kalanchoe daigremontiana were rough and contained

Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis, 1972

ABSTRACT A number of isogenic radiation-sensitive strains of E. coli K12 were tested for their ab... more ABSTRACT A number of isogenic radiation-sensitive strains of E. coli K12 were tested for their ability to reactivate 32P decay-damaged λ phage. The loss of the Rec, Uvr, Exr and Ror functions does not affect the reactivation of the damaged phage. In contrast, the loss of the Pol function reduces the reactivation efficiency. It is estimated that polAi strain is 5 times less efficient in the repair of single-strand breaks than the pol+ strain.

Energy & Environment, 2010

A paradigm is a set of scientific and metaphysical beliefs that provide a theoretical framework w... more A paradigm is a set of scientific and metaphysical beliefs that provide a theoretical framework within which scientific theories can be tested. Replacement of an existing paradigm by another is called a paradigm shift. Most of the following papers in this issue argue that an alternative paradigm is needed for the functioning of the so-called greenhouse effect of the Earth and hence for the explanation of observed climatic change. Some others contest it. The observed coincidence between global warming and rise of CO2 in the atmosphere over the last century -more accurately measured over the last 30 years of it – need not indicate a causal relationship, and it certainly need not give rise to global catastrophe. An assumed correlation is based on the expectation that the infrared radiation from CO2 contributes significantly to the greenhouse effect of the Earth. However, irregularities in the trends raise doubts of such a simple causal relationship and, at least, considerable doubt about the magnitude of such an expected effect.

Energy & Environment, 2013

The strong climate-forcing effect of rising atmospheric CO2 concentrations advocated by the IPCC,... more The strong climate-forcing effect of rising atmospheric CO2 concentrations advocated by the IPCC, is at odds with climate developments during geological, historical and recent times. Although atmospheric CO2 concentrations continuously increased during industrial times, temperatures did not increase continuously to the present level but stagnated or even declined slightly during 1880 to 1900, 1945 to1977 and again since 1998. Total solar irradiation rose from a low in 1890 to a first peak in 1950 that was followed by a sharp decline ending in 1977, giving way to a period of rapidly increasing radiation peaking in 2002 when solar activity started to decrease, possibly declining to a new Little-Ice-Age type low. The Greenhouse Effect of increasing atmospheric CO2 concentrations, claimed and widely propagated by IPCC, is particularly vexing as it is widely over-estimated without adequate scientific justification. Large observed climate variations documented for geological and historica...

Humanities, 2014

Scientific orthodoxy based on the acquired authority of some scientists has seriously hampered th... more Scientific orthodoxy based on the acquired authority of some scientists has seriously hampered the progress of the natural sciences in the past and continues to do so today because of new societal influences, such as directive funding and political interference in the setting of research objectives. Enhancing the progress of science must continue to be an important priority in order to meet the future needs of mankind. Yet priority setting between different branches of research is currently controversial because of the limited availability of funds and the political interference. For sound priority setting, an adequate level of scientific literacy is required among policy makers, a subject that will attract attention throughout this paper. The "introduction" gives an overview of the issues at stake. Prevailing pessimistic views of the future of our complex society are viewed as being similar to a medieval doomsday syndrome. Pathways to a new renaissance and age of reason are suggested. Three major recommendations are made: (i) Freedom of inquiry must be protected; (ii) The political misuse of potential environmental scares needs to be investigated before doomsday predictions alarm public perceptions and hence shape policies; (iii) The search for excellence in the leadership of science should be emphasized because it should not be based largely on acquired authority. The current controversy over possible impacts of rising levels of CO 2 in the atmosphere on climate is analyzed as a case study.

Quarterly Reviews of Biophysics, 1974

Genetic engineering has quite rightly an image of science fiction. The time when new species with... more Genetic engineering has quite rightly an image of science fiction. The time when new species with any wanted combination of genetic properties can be ordered from an animal or plant breeding factory seems far away. The layman's view that the science fiction of today is the reality of tomorrow is certainly an insufficient argument to justify optimism. If this were so, we should by now be able to produce hybrids between members of the animal and plant kingdom as was foreseen by a nineteenth-century equivalent of Fred Hoyle (see Fig. I). Despite the scepsis expressed by the prominent scientist Si.r Macfarlane Burnet in his book Genes, Dreams and Realities (1971), recent advances in molecular genetics have raised new enthusiasm (and uneasiness) which make people speak of genetic engineering as something to aim at as an approach to correct inborn errors of metabolism. This will, however, not be our principal dish if we restrict ourselves to a vegetarian menu. We view genetic engineer...

European Journal of Biochemistry, 1973

The killing of highly 32P-labelled bacteriophage MS2 by transmutation was studied. The efficiency... more The killing of highly 32P-labelled bacteriophage MS2 by transmutation was studied. The efficiency of killing found was 0.60 & 0.08. This value is significantly lower than the value expected for a single-stranded bacteriophage. These results can be interpreted by assuming either that the MS2 RNA is replicated with the breaks caused by radiophosphorus decay, or that the breaks are repaired before replication. Considerable information is available regarding the killing of DNA bacteriophages by transmutation of s2P. The efficiency of killing of double-stranded DNA bacteriophages is in the range of 1 per 10 disintegrations. T phages, for example, demonstrate an efficiency of killing (01) of 0.12 to 0.19 [l], suggesting that most 32P disintegrations in these phages are not lethal. On the other hand suicide studies using the single-stranded DNA bacteriophages qX 174 and 513, show that all 32P disintegrations are lethal,

Energy & Environment is now available on-line, free to subscribers to the printed edition. For ac... more Energy & Environment is now available on-line, free to subscribers to the printed edition. For access details contact Multi-Science.

European Journal of Biochemistry, 1974

ABSTRACT A procedure is described which can be employed to isolate the thermosensitive mutants of... more ABSTRACT A procedure is described which can be employed to isolate the thermosensitive mutants of Escherichia coli affected in protein synthesis. The technique involves the enrichment of cells unable to propagate MS2 phage at 42 °C and the subsequent screening for thermosensitive growth and protein synthesis. Two of the mutants isolated in this way, QL-152 and QL-199, were studied in some detail. The synthesis of glutamyl-tRNA by QL-152 supernatant enzyme appeared to be thermosensitive. In the case of QL-199 a 65% reduction of the glutaminyl-tRNA synthesis was measured. Moreover QL-199 cells contain an elongation factor EF-Tu which is more thermolabile than wild-type EF-Tu.

Journal of Information Ethics, 2005

Modern science proceeds through theories that are tested by observations. If these do not fit the... more Modern science proceeds through theories that are tested by observations. If these do not fit the assumptions, new theories are developed to replace the former ones (see Carl Popper and Thomas Kuhn)([1]). In the history of science there have been several long periods ...

Journal of General Microbiology, 1977

A mutant of A . tumefaciens strain ~6~3 , carrying the R factor RP4, was able to transfer its TI ... more A mutant of A . tumefaciens strain ~6~3 , carrying the R factor RP4, was able to transfer its TI plasmid to various avirulent Agrobacterium strains and to a strain of Rhizobium. Strains carrying the TI(~6s3) plasmid were selected by their ability to utilize octopine. The isolates were able to induce tumours and exclude phage API . The tumours induced on Kalanchoe daigremontiana were rough and contained

Scientific orthodoxy based on the acquired authority of some scientists has seriously hampered th... more Scientific orthodoxy based on the acquired authority of some scientists has seriously hampered the progress of the natural sciences in the past and continues to do so today because of new societal influences, such as directive funding and political interference in the setting of research objectives. Enhancing the progress of science must continue to be an important priority in order to meet the future needs of mankind. Yet priority setting between different branches of research is currently controversial because of the limited availability of funds and the political interference. For sound priority setting, an adequate level of scientific literacy is required among policy makers, a subject that will attract attention throughout this paper.

Arthur Rorsch, Pieterskerkhof 40c, 2311 ST Leiden, The Netherlands. MSc Degree in Chemical Engine... more Arthur Rorsch, Pieterskerkhof 40c, 2311 ST Leiden, The Netherlands. MSc Degree in Chemical Engineering Universiy of Delft, 1957. PhD Leiden University 1962 Researcher in molecular radiation biology 1957-1973, Professor of Molecular Genetics, Medical Faculty Leiden University, 1967-1997 Vice President of the Netherlands Organization of Aplied Research TNO, responsible for Nutrition, Public Health and Environmental Research, 1980-1995

Mutat Res Fundam Mol Mech Mut, 1972

Journal of General Microbiology, 1975

A procedure to enrich for auxotrophic and fermentation mutants of Agrobacterium turnefaciens is d... more A procedure to enrich for auxotrophic and fermentation mutants of Agrobacterium turnefaciens is described. The method is based on the amplification

Energy & Environment, 2005

This paper provides a literature study of the observations on temperature changes and the accumul... more This paper provides a literature study of the observations on temperature changes and the accumulation of carbon dioxide in the atmosphere. It investigates the cause-effect relationship between these parameters, and makes an alternative interpretation to that given by the UN Intergovernmental Panel on Climate Change (IPCC).

Energy & Environment, 2005

The flow of carbon dioxide through the atmosphere is a complex system because it consists of seve... more The flow of carbon dioxide through the atmosphere is a complex system because it consists of several cycles; e.g., through the biosphere which produces and consumes it, and through the Earth's water surfaces which absorb and emit it. These processes are dependent on temperature but their reactions to temperature have different signs. Temperature rise promotes both the consumption and the production of carbon dioxide by the biosphere but liberates carbon dioxide from water surfaces. This paper offers a comprehensive review of the behaviour of these processes. It considers these flows and assesses observations of the movement of carbon dioxide to and from the atmosphere. The disturbance of the natural cycle by current anthropogenic emissions is used as an instrument to throw light on what is actually happening to cause alteration to atmospheric carbon dioxide concentration. Also, these considerations are used in attempts to model the processes with mathematical equations derived from physics and biology. It...

Energy & Environment, Mar 1, 2005

The flow of carbon dioxide through the atmosphere is a complex system because it consists of seve... more The flow of carbon dioxide through the atmosphere is a complex system because it consists of several cycles; e.g., through the biosphere which produces and consumes it, and through the Earth's water surfaces which absorb and emit it. These processes are dependent on temperature but their reactions to temperature have different signs. Temperature rise promotes both the consumption and the production of carbon dioxide by the biosphere but liberates carbon dioxide from water surfaces. This paper offers a comprehensive review of the behaviour of these processes. It considers these flows and assesses observations of the movement of carbon dioxide to and from the atmosphere. The disturbance of the natural cycle by current anthropogenic emissions is used as an instrument to throw light on what is actually happening to cause alteration to atmospheric carbon dioxide concentration. Also, these considerations are used in attempts to model the processes with mathematical equations derived from physics and biology. It...

It is shown that a large plasmid in A. tumefaciens cells, called the TI-plasmid, besides being es... more It is shown that a large plasmid in A. tumefaciens cells, called the TI-plasmid, besides being essential for oncogenicity also determines: (1) the specificity and the activity of the enzyme-system for octopine or nopaline utilisation; (2) the synthesis of either octopine or nopaline in crown gall cells as well as the morphology of the tumors on Kalanchoe stems. A few A. tumefaciens strains give rise to tumors whose cells do not synthesise octopine or nopaline. This indicates that these compounds themselves are not essential for the tumorous nature of the plant cells. Roots induced by the hairy root disease bacteria of two A. rhizogenes strains tested do not contain nopaline or octopine. Although octopine or nopaline could also not be detected in normal tissues of Kalanchoe, teratomata and aberrant looking roots developing from tumors do contain the same type of guanidine derivative as present in the tumor from which they develop. This suggests that once synthesis of the unusual guan...

Journal of Bacteriology, 1973

Strains carrying either the polA1 or resA1 mutation are deficient in DNA polymerase I, and the po... more Strains carrying either the polA1 or resA1 mutation are deficient in DNA polymerase I, and the polA1 and resA1 mutations do not complement in merozygotes. The effect of these mutations in otherwise identical genetic backgrounds was studied: after ultraviolet irradiation both strains degrade their DNA more rapidly and more extensively than the wild-type strains. However, after X-ray irradiation the resA1 strain shows little DNA breakdown and repairs its single-strand breaks. In contrast, the polA1 strain degrades its DNA extensively, and single-strand breaks are not repaired. Moreover, the resA1 strain is capable of supporting the growth of a red − bacteriophage lambda, whereas the polA1 strain is not.

Journal of General Microbiology, 1977

A mutant of A. tumefaciens strain ~6~3 , carrying the R factor RP4, was able to transfer its TI p... more A mutant of A. tumefaciens strain ~6~3 , carrying the R factor RP4, was able to transfer its TI plasmid to various avirulent Agrobacterium strains and to a strain of Rhizobium. Strains carrying the TI(~6s3) plasmid were selected by their ability to utilize octopine. The isolates were able to induce tumours and exclude phage API. The tumours induced on Kalanchoe daigremontiana were rough and contained

Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis, 1972

ABSTRACT A number of isogenic radiation-sensitive strains of E. coli K12 were tested for their ab... more ABSTRACT A number of isogenic radiation-sensitive strains of E. coli K12 were tested for their ability to reactivate 32P decay-damaged λ phage. The loss of the Rec, Uvr, Exr and Ror functions does not affect the reactivation of the damaged phage. In contrast, the loss of the Pol function reduces the reactivation efficiency. It is estimated that polAi strain is 5 times less efficient in the repair of single-strand breaks than the pol+ strain.

Energy & Environment, 2010

A paradigm is a set of scientific and metaphysical beliefs that provide a theoretical framework w... more A paradigm is a set of scientific and metaphysical beliefs that provide a theoretical framework within which scientific theories can be tested. Replacement of an existing paradigm by another is called a paradigm shift. Most of the following papers in this issue argue that an alternative paradigm is needed for the functioning of the so-called greenhouse effect of the Earth and hence for the explanation of observed climatic change. Some others contest it. The observed coincidence between global warming and rise of CO2 in the atmosphere over the last century -more accurately measured over the last 30 years of it – need not indicate a causal relationship, and it certainly need not give rise to global catastrophe. An assumed correlation is based on the expectation that the infrared radiation from CO2 contributes significantly to the greenhouse effect of the Earth. However, irregularities in the trends raise doubts of such a simple causal relationship and, at least, considerable doubt about the magnitude of such an expected effect.

Energy & Environment, 2013

The strong climate-forcing effect of rising atmospheric CO2 concentrations advocated by the IPCC,... more The strong climate-forcing effect of rising atmospheric CO2 concentrations advocated by the IPCC, is at odds with climate developments during geological, historical and recent times. Although atmospheric CO2 concentrations continuously increased during industrial times, temperatures did not increase continuously to the present level but stagnated or even declined slightly during 1880 to 1900, 1945 to1977 and again since 1998. Total solar irradiation rose from a low in 1890 to a first peak in 1950 that was followed by a sharp decline ending in 1977, giving way to a period of rapidly increasing radiation peaking in 2002 when solar activity started to decrease, possibly declining to a new Little-Ice-Age type low. The Greenhouse Effect of increasing atmospheric CO2 concentrations, claimed and widely propagated by IPCC, is particularly vexing as it is widely over-estimated without adequate scientific justification. Large observed climate variations documented for geological and historica...

Humanities, 2014

Scientific orthodoxy based on the acquired authority of some scientists has seriously hampered th... more Scientific orthodoxy based on the acquired authority of some scientists has seriously hampered the progress of the natural sciences in the past and continues to do so today because of new societal influences, such as directive funding and political interference in the setting of research objectives. Enhancing the progress of science must continue to be an important priority in order to meet the future needs of mankind. Yet priority setting between different branches of research is currently controversial because of the limited availability of funds and the political interference. For sound priority setting, an adequate level of scientific literacy is required among policy makers, a subject that will attract attention throughout this paper. The "introduction" gives an overview of the issues at stake. Prevailing pessimistic views of the future of our complex society are viewed as being similar to a medieval doomsday syndrome. Pathways to a new renaissance and age of reason are suggested. Three major recommendations are made: (i) Freedom of inquiry must be protected; (ii) The political misuse of potential environmental scares needs to be investigated before doomsday predictions alarm public perceptions and hence shape policies; (iii) The search for excellence in the leadership of science should be emphasized because it should not be based largely on acquired authority. The current controversy over possible impacts of rising levels of CO 2 in the atmosphere on climate is analyzed as a case study.

Quarterly Reviews of Biophysics, 1974

Genetic engineering has quite rightly an image of science fiction. The time when new species with... more Genetic engineering has quite rightly an image of science fiction. The time when new species with any wanted combination of genetic properties can be ordered from an animal or plant breeding factory seems far away. The layman's view that the science fiction of today is the reality of tomorrow is certainly an insufficient argument to justify optimism. If this were so, we should by now be able to produce hybrids between members of the animal and plant kingdom as was foreseen by a nineteenth-century equivalent of Fred Hoyle (see Fig. I). Despite the scepsis expressed by the prominent scientist Si.r Macfarlane Burnet in his book Genes, Dreams and Realities (1971), recent advances in molecular genetics have raised new enthusiasm (and uneasiness) which make people speak of genetic engineering as something to aim at as an approach to correct inborn errors of metabolism. This will, however, not be our principal dish if we restrict ourselves to a vegetarian menu. We view genetic engineer...

European Journal of Biochemistry, 1973

The killing of highly 32P-labelled bacteriophage MS2 by transmutation was studied. The efficiency... more The killing of highly 32P-labelled bacteriophage MS2 by transmutation was studied. The efficiency of killing found was 0.60 & 0.08. This value is significantly lower than the value expected for a single-stranded bacteriophage. These results can be interpreted by assuming either that the MS2 RNA is replicated with the breaks caused by radiophosphorus decay, or that the breaks are repaired before replication. Considerable information is available regarding the killing of DNA bacteriophages by transmutation of s2P. The efficiency of killing of double-stranded DNA bacteriophages is in the range of 1 per 10 disintegrations. T phages, for example, demonstrate an efficiency of killing (01) of 0.12 to 0.19 [l], suggesting that most 32P disintegrations in these phages are not lethal. On the other hand suicide studies using the single-stranded DNA bacteriophages qX 174 and 513, show that all 32P disintegrations are lethal,

Energy & Environment is now available on-line, free to subscribers to the printed edition. For ac... more Energy & Environment is now available on-line, free to subscribers to the printed edition. For access details contact Multi-Science.

European Journal of Biochemistry, 1974

ABSTRACT A procedure is described which can be employed to isolate the thermosensitive mutants of... more ABSTRACT A procedure is described which can be employed to isolate the thermosensitive mutants of Escherichia coli affected in protein synthesis. The technique involves the enrichment of cells unable to propagate MS2 phage at 42 °C and the subsequent screening for thermosensitive growth and protein synthesis. Two of the mutants isolated in this way, QL-152 and QL-199, were studied in some detail. The synthesis of glutamyl-tRNA by QL-152 supernatant enzyme appeared to be thermosensitive. In the case of QL-199 a 65% reduction of the glutaminyl-tRNA synthesis was measured. Moreover QL-199 cells contain an elongation factor EF-Tu which is more thermolabile than wild-type EF-Tu.

Journal of Information Ethics, 2005

Modern science proceeds through theories that are tested by observations. If these do not fit the... more Modern science proceeds through theories that are tested by observations. If these do not fit the assumptions, new theories are developed to replace the former ones (see Carl Popper and Thomas Kuhn)([1]). In the history of science there have been several long periods ...

Journal of General Microbiology, 1977

A mutant of A . tumefaciens strain ~6~3 , carrying the R factor RP4, was able to transfer its TI ... more A mutant of A . tumefaciens strain ~6~3 , carrying the R factor RP4, was able to transfer its TI plasmid to various avirulent Agrobacterium strains and to a strain of Rhizobium. Strains carrying the TI(~6s3) plasmid were selected by their ability to utilize octopine. The isolates were able to induce tumours and exclude phage API . The tumours induced on Kalanchoe daigremontiana were rough and contained

Scientific orthodoxy based on the acquired authority of some scientists has seriously hampered th... more Scientific orthodoxy based on the acquired authority of some scientists has seriously hampered the progress of the natural sciences in the past and continues to do so today because of new societal influences, such as directive funding and political interference in the setting of research objectives. Enhancing the progress of science must continue to be an important priority in order to meet the future needs of mankind. Yet priority setting between different branches of research is currently controversial because of the limited availability of funds and the political interference. For sound priority setting, an adequate level of scientific literacy is required among policy makers, a subject that will attract attention throughout this paper.