In vitro strategies for improvement of frost tolerance in cauliflower.

Two in vitro selection strategies were employed in an effort to obtain cauliflower lines with improved cold tolerance

Selection of hydroxyproline-resistant proline-accumulating mutants of cauliflower. C.R. Deane, M .P. Fuller' & P.J. Dix

A procedure is described by which hydroxyproline-resistant lines could be selected from regenerating curd tissue of cauliflower. Mutagenesis was by N-nitroso-N-ethylurea, supplied as a drop of 0 .3 mM solution on each 3 mm diameter curd piece. The mutagen generated numerous morphological and pigment mutations without significantly affecting shoot regeneration from explants . Thirty one resistant shoots were recovered from more than six thousand explants mutagenised on regeneration medium supplemented with 3 mM hydroxyproline, while none was obtained from a similar number of non-mutagenised controls . Out of twenty-three resistant shoots which survived subculture, only one showed consistently elevated levels of endogenous proline . During early shoot culture passages, proline levels were 3 .6-4.7 times higher than controls, but this was reduced to 1 .6 times after 10-12 culture passages in the absence of hydroxyproline . Possible reasons for this decline are discussed . Leaf strip assays suggest resistant shoots may be chimeras and current efforts are directed towards regenerating solid mutants from resistant sectors . These will then be evaluated for any alteration in frost tolerance

Selection of hydroxyproline-resistant proline-accumulating mutants of cauliflower. C.R. Deane, M .P. Fuller' & P.J. Dix

A procedure is described by which hydroxyproline-resistant lines could be selected from regenerating curd tissue of cauliflower. Mutagenesis was by N-nitroso-N-ethylurea, supplied as a drop of 0 .3 mM solution on each 3 mm diameter curd piece. The mutagen generated numerous morphological and pigment mutations without significantly affecting shoot regeneration from explants . Thirty one resistant shoots were recovered from more than six thousand explants mutagenised on regeneration medium supplemented with 3 mM hydroxyproline, while none was obtained from a similar number of non-mutagenised controls . Out of twenty-three resistant shoots which survived subculture, only one showed consistently elevated levels of endogenous proline . During early shoot culture passages, proline levels were 3 .6-4.7 times higher than controls, but this was reduced to 1 .6 times after 10-12 culture passages in the absence of hydroxyproline . Possible reasons for this decline are discussed . Leaf strip assays suggest resistant shoots may be chimeras and current efforts are directed towards regenerating solid mutants from resistant sectors . These will then be evaluated for any alteration in frost tolerance

In vitro strategies for improvement of frost tolerance in cauliflower.

Two in vitro selection strategies were employed in an effort to obtain cauliflower lines with improved cold tolerance

Early enteral nutrition in critically ill patients: ESICM clinical practice guidelines.

To provide evidence-based guidelines for early enteral nutrition (EEN) during critical illness. We aimed to compare EEN vs. early parenteral nutrition (PN) and vs. delayed EN. We defined "early" EN as EN started within 48 h independent of type or amount. We listed, a priori, conditions in which EN is often delayed, and performed systematic reviews in 24 such subtopics. If sufficient evidence was available, we performed meta-analyses; if not, we qualitatively summarized the evidence and based our recommendations on expert opinion. We used the GRADE approach for guideline development. The final recommendations were compiled via Delphi rounds. We formulated 17 recommendations favouring initiation of EEN and seven recommendations favouring delaying EN. We performed five meta-analyses: in unselected critically ill patients, and specifically in traumatic brain injury, severe acute pancreatitis, gastrointestinal (GI) surgery and abdominal trauma. EEN reduced infectious complications in unselected critically ill patients, in patients with severe acute pancreatitis, and after GI surgery. We did not detect any evidence of superiority for early PN or delayed EN over EEN. All recommendations are weak because of the low quality of evidence, with several based only on expert opinion. We suggest using EEN in the majority of critically ill under certain precautions. In the absence of evidence, we suggest delaying EN in critically ill patients with uncontrolled shock, uncontrolled hypoxaemia and acidosis, uncontrolled upper GI bleeding, gastric aspirate >500 ml/6 h, bowel ischaemia, bowel obstruction, abdominal compartment syndrome, and high-output fistula without distal feeding access

Should science educators deal with the science/religion issue?

I begin by examining the natures of science and religion before looking at the ways in which they relate to one another. I then look at a number of case studies that centre on the relationships between science and religion, including attempts to find mechanisms for divine action in quantum theory and chaos theory, creationism, genetic engineering and the writings of Richard Dawkins. Finally, I consider some of the pedagogical issues that would need to be considered if the science/religion issue is to be addressed in the classroom. I conclude that there are increasing arguments in favour of science educators teaching about the science/religion issue. The principal reason for this is to help students better to learn science. However, such teaching makes greater demands on science educators than has generally been the case. Certain of these demands are identified and some specific suggestions are made as to how a science educator might deal with the science/religion issue. © 2008 Taylor & Francis