2,936 research outputs found
Breeding wheat varieties for acid soils
Wheat varieties with improved tolerance of acid soils cold increase yeilds be perhaps 20 per cent or more over a substantialarea ofWestern Australia\u27s eastern wheatbelt.
Aluminium toxicity is probably the main cause of poor root growth and therefore reduced yields on these soils
Governance of tuna industries: The key to economic viability and sustainability in the Western and Central Pacific Ocean
The Western and Central Pacific Ocean (WCPO) tuna fishery is an important global food resource, and the economies of many Pacific Islands Countries (PICs) rely heavily on tuna industries. This paper proposes that governance by PICs is the key to improving the sustainability and profitability of tuna industries in the region. 'Governance' is usually used to refer to corruption, but here is interpreted more broadly to encompass the whole process by which decisions regarding public life are made and enacted, by government and also civil society. Argument is supported by empirical material from an interview study with stakeholders and a survey of reports. © 2006 Elsevier Ltd. All rights reserved
Coupling of nitrogen-vacancy centers in diamond to a GaP waveguide
The optical coupling of guided modes in a GaP waveguide to nitrogen-vacancy
(NV) centers in diamond is demonstrated. The electric field penetration into
diamond and the loss of the guided mode are measured. The results indicate that
the GaP-diamond system could be useful for realizing coupled microcavity-NV
devices for quantum information processing in diamond.Comment: 4 pages 4 figure
Withdrawal of anticancer therapy in advanced disease: a systematic literature review
Abstract
Background
Current guidelines set out when to start anticancer treatments, but not when to stop as the end of life approaches. Conventional cytotoxic agents are administered intravenously and have major life-threatening toxicities. Newer drugs include molecular targeted agents (MTAs), in particular, small molecule kinase-inhibitors (KIs), which are administered orally. These have fewer life-threatening toxicities, and are increasingly used to palliate advanced cancer, generally offering additional months of survival benefit. MTAs are substantially more expensive, between £2-8 K per month, and perceived as easier to start than stop.
Methods
A systematic review of decision-making concerning the withdrawal of anticancer drugs towards the end of life within clinical practice, with a particular focus on MTAs. Nine electronic databases searched. PRISMA guidelines followed.
Results
Forty-two studies included. How are decisions made? Decision-making was shared and ongoing, including stopping, starting and trying different treatments. Oncologists often experienced ‘professional role dissonance’ between their self-perception as ‘treaters’, and talking about end of life care. Why are decisions made? Clinical factors: disease progression, worsening functional status, treatment side-effects. Non-clinical factors: physicians’ personal experience, values, emotions. Some patients continued treatment to maintain ‘hope’, often reflecting limited understanding of palliative goals. When are decisions made? Limited evidence reveals patients’ decisions based upon quality of life benefits. Clinicians found timing withdrawal particularly challenging. Who makes the decisions? Decisions were based within physician-patient interaction.
Conclusions
Oncologists report that decisions around stopping chemotherapy treatment are challenging, with limited evidence-based guidance outside of clinical trial protocols. The increasing availability of oral MTAs is transforming the management of incurable cancer; blurring boundaries between active treatment and palliative care. No studies specifically addressing decision-making around stopping MTAs in clinical practice were identified. There is a need to develop an evidence base to support physicians and patients with decision-making around the withdrawal of these high cost treatments
Frequencies of Lipopolysaccharide Core Types among Clinical Isolates of Escherichia coli Defined with Monoclonal Antibodies
Mouse monoclonal antibodies (MAbs) specific for the lipopolysaccharide (LPS) core types R1, R2, and R3 of Escherichia coli and a cross-reactive MAb that binds to the LPS core of almost all E. coli were used in ELISA to determine the frequency of cores resembling R1, R2, and R3 in strains of E. coli isolated from clinical samples (blood and urine specimens) and from the feces of asymptomatic individuals. Of the 180 wild-type isolates, 123 were assigned to R1 core type, 14 to R2, and 18 to R3. Twenty-five wild-type E. coli isolates could not be assigned to a particular core type and may have either an R4 or K12 core or a previously unrecognized core type. R1 core type was associated with O types 1, 4, 6, 8, and 18 and with K1 or K5 capsules. R3 was associated with O15.O75 isolates could be of either R1 or R2 core typ
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'Can you be a doctor, even if you faint?' The tacit lessons of cadaveric dissection
Background: The undergraduate Medicine course at the University of Cambridge has included cadaveric dissection as part of its anatomy teaching for over three centuries. In recent years, medical schools in the UK and the US have debated whether cadaveric dissection is a useful and efficient way of teaching anatomy. Existing research on this subject has focused narrowly on the knowledge-acquisition for medical students afforded through dissection, and thus we have broadened the scope of such considerations to include the emotional responses of medical students to the dissection process.
Subjects and methods: The basis for this paper is a phenomenological analysis of response data gathered from 56 first year medical students at the University of Cambridge through written questionnaires and discussion groups before and after their first experiences of cadaveric dissection.
Results: Our research suggests that there are in fact many more lessons taught and acquired through studying in the dissection room: they are tacit, emotional, experiential and dispositional.
Conclusions: When this wider picture of the value of dissection is considered, a much stronger case for the continued inclusion of cadaveric dissection in the medical curriculum can be made, as it is a valuable and unique educational experience
Aspects of ribonucleic acid biosynthesis in mammalian cells
1. Experiments were carried out in vitro to characterise the RNA polymerase found in the nuclei of Landschutz ascites ttraiour cells. 2. The enzyme was found to be dependent on DM as a primer. The level of incorporation of ribonucleoside triphosphates was found to increase when all four ribonucleoside triphosphates were present. This incorporation was stimulated by the presence of up to 1 mumole/assay of Mn2 and to a lesser extent by Mg2. Ammonium sulphate was shown to raise the specific activity of the enzyme, the extent of the rise being peculiar to this salt. A requirement was also shown for 2-mercapto-ethanol. 3. Attempts were made to purify the fraction containing RNA polymerase. These were restricted owing to the aggregate form of the enzyme. The preparation was treated with DNase or micrococcal nuclease to destroy the native DNA present. The treated preparations were then fractionated on DEAE cellulose but subsequent recoveries of RNA polymerase were not reproducible. Treated and untreated polymerase preparations were fractionated by means of sucrose or glycerol gradients but no satisfactory separation was obtained. 4. Solutions of the aggregate preparation were made in various organic solvents. Sodium deoxycholate was found to give increased incorporation of ribonucleoside triphosphates and was therefore used in subsequent experiments. Several fractionation techniques were tested using the detergent treated preparation. Addition of streptomycin sulphate followed by removal of the resulting precipitate was found to reduce the concentration of DNA present while increasing the specific activity of the RNA polymerase. 5. The characteristics of the streptomycin sulphate supernatant were established and compared with those of the crude preparation. The purified enzyme maintains the same characteristics with respect to Mn2 Mg2 and ammonium sulphate, but no longer requires the presence of 2-mercapto-ethanol. RNA as well as DNA can be accepted by the streptomycin preparation as primer, although the addition of DNase to the reaction mixture, in the absence of added polynucleotide, still causes a lower rate of incorporation. 6. Incorporation of ribonucleoside triphosphates by the crude enzyme was found to take place in the presence and absence of ammonium sulphate. This incorporation as already noted, was stimulated, in the presence of ammonium sulphate, by the addition of the other three ribonucleotides. In the absence of ammonium sulphate no such stimulation was obtained, suggesting the formation of homopolymers. There was no incorporation of ribonucleotides by the purified preparation in the absence of ammonium sulphate, but in its presence addition of all four ribonucleotides caused an increase in enzyme activity. 7. In the presence of only one ribonucleoside 5'-triphosphate, the highest rate of incorporation by the crude enzyme was obtained with [3H]UTP, the lowest rate with [3H]GTP. Several experiments were performed using first [3H]UTP and later
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