Time resolution of Burle 85001 micro-channel plate photo-multipliers in comparison with Hamamatsu R2083

The CLAS detector will require improvements in its particle identification system to take advantage of the higher energies provided by the Jefferson Laboratory accelerator upgrade to 12 GeV. To this end, we have studied the timing characteristics of the micro-channel plate photo-multiplier 85001 from Burle, which can be operated in a high magnetic field environment. For reference and comparison, measurements were also made using the standard PMT R2083 from Hamamatsu using two timing methods. The cosmic ray method, which utilizes three identical scintillating counters 2cmx3cmx50cm with PMs at the ends, yields 59.1(0.7)ps. The location method of particles from radiative source with known coordiantes has been used to compare timing resolutions of R2083 and Burle-85001.This ``coordinate method'' requires only one counter instrumented with two PMs and it yields 59.5(0.7)ps. For the micro-channel plate photomultiplier from Burle with an external amplification of 10 to the signals, the coordinate method yields 130(4)ps. This method also makes it possible to estimate the number of primary photo-electrons.Comment: 23 pages, 13 figure

Time resolution of Burle 85001 micro-channel plate photo-multipliers in comparison with Hamamatsu R2083

The CLAS detector will require improvements in its particle identification system to take advantage of the higher energies provided by the Jefferson Laboratory accelerator upgrade to 12 GeV. To this end, we have studied the timing characteristics of the micro-channel plate photo-multiplier 85001 from Burle, which can be operated in a high magnetic field environment. For reference and comparison, measurements were also made using the standard PMT R2083 from Hamamatsu using two timing methods. The cosmic ray method, which utilizes three identical scintillating counters 2cmx3cmx50cm with PMs at the ends, yields 59.1(0.7)ps. The location method of particles from radiative source with known coordiantes has been used to compare timing resolutions of R2083 and Burle-85001.This ``coordinate method'' requires only one counter instrumented with two PMs and it yields 59.5(0.7)ps. For the micro-channel plate photomultiplier from Burle with an external amplification of 10 to the signals, the coordinate method yields 130(4)ps. This method also makes it possible to estimate the number of primary photo-electrons.Comment: 23 pages, 13 figure

Ultra high diluted arsenic reduces spore germination of Alternaria brassicicola and dark leaf spot in cauliflower

ABSTRACT A major problem in cauliflower crop is the fungus Alternaria brassicicola, which causes dark leaf spot on Brassicaceae family. The current use of copper salts in agriculture is questioned. In fact, these products present some disadvantages, connected mainly with their deposits in the soil and toxicity on plants. This work investigated the effects of arsenic treatments, in ultra high diluted form (UHD), prepared by a process of repeated dilution and succussion (shaking), through: 1) in vitro germination experiments, where spores of A. brassicicola were suspended in the treatments; 2) in planta experiments and 3) a field trial, where cauliflower plants infected by the fungus were sprayed with treatments. The results showed that ultra high dilutions of arsenic (where no more molecules of this substance are present) were effective in all the experiments, inhibiting spore germination by 60.0%, controlling fungal disease in in planta experiments (relative efficacy of 42.1%), and, in field trial, decreasing the mean infection level in cauliflower heads by 45.7% and 41.6% in artificially inoculated and naturally infected plants, respectively. This is the first study to demonstrate that ultra high dilutions effectively reduce in vitro spore germination and infection of A. brassicicola in cauliflower plants, both under controlled conditions and in the field. Our research is still very experimental, however, in light of the significant results obtained with ultra-diluted arsenic, and given that its extreme high dilution level precludes any toxicity or accumulation in the environment, the use of UHDs could be considered a potential and reliable approach for sustainable agriculture

Use of plant bioasssys in homeopathic basic research: a systematic review

Experimental research on the effects of treatments with homeopathic preparations on plants was last reviewed in 1990. The objective was to compile a systematic literature review on plant bioassays in homeopathic basic research using predefined criteria. A literature search was carried out on publications that reported experiments with homeopathic preparations on whole plants, seeds, plant parts and cells from 1920 to 2010, in healthy, abiotically or biotically stressed conditions. Outcomes had to be measured by established state-of-the-art procedures and statistically evaluated. Using a Manuscript Information Score (MIS), publications were identified that provided sufficient information for proper interpretation (MIS > 5). Further evaluation focused on the use of adequate controls to investigate specific effects of homeopathic preparations and on the use of systematic negative control experiments to ensure proper system performance. A total of 157 publications with plants were identified. The 157 publications described a total of 167 experimental studies. Eighty-four studies included statistics and 48 had a MIS > 5 allowing proper interpretation. Twenty-nine studies were identified with adequate controls to identify specific effects of homeopathic preparations, reporting significant effects of decimal and centesimal homeopathic potencies, including dilution levels beyond Avogadro’s number. Studies that tested series of consecutive potency levels reported a non-linear and discontinuous relation between effect and potency level. There were many individual studies with diverse methods and very few replication trials. Ten studies reported use of systematic negative control experiments, yielding evidence for the stability of the experimental set-up. Plant models appear to be a useful approach to investigate basic research questions on homeopathic preparations, but more independent replication trials are needed. Systematic negative control experiments should be implemented on a routine basis to exclude false-positive results

Use of homeopathic preparations in phytopathological models and in field trials: a critical review

The literature on the applications of homeopathy for controlling plant diseases in both plant pathological models and field trials was first reviewed by Scofield in 1984. No other review on homeopathy in plant pathology has been published since, though much new research has subsequently been carried out using more advanced methods. The objective of this work was to conduct an up-to-date review of the existing literature on basic research in homeopathy using phytopathological models and experiments in the field. A literature search was carried out on publications from 1969 to 2009, for papers that reported experiments on homeopathy using phytopathological models (in vitro and in planta) and field trials. The selected papers were summarised and analysed on the basis of a Manuscript Information Score (MIS) to identify those that provided sufficient information for proper interpretation (MIS ≥ 5). These were then evaluated using a Study Methods Evaluation Procedure (SMEP). A total of 44 publications on phytopathological models were identified: 19 papers with statistics, 6 studies with MIS ≥ 5. Publications on field were 9, 6 with MIS ≥ 5. In general, significant and reproducible effects with decimal and centesimal potencies were found, including dilution levels beyond the Avogadro\u2019s number. The prospects for homeopathic treatments in agriculture are promising, but much more experimentation is needed, especially at a field level, and on potentisation techniques, effective potency levels and conditions for reproducibility. Phytopathological models may also develop into useful tools to answer pharmaceutical questions

Use of homeopathic preparations in experimental studies with healthy plants

The last comprehensive review of experimental research on effects of homeopathic treatments on plants was published in 1984, and lacked formal predefined criteria to assess study quality. Since then several new studies with more advanced methods have been published. The objective was to compile a review of the literature on basic research in homeopathy with healthy plants with particular reference to studies investigating specific effects of homeopathic remedies. The literature search included English, French, German, Italian, Portuguese and Spanish publications from 1920 to April 2009, using predefined selection criteria. We included experiments with healthy whole plants, seeds, plant parts and cells. The outcomes had to be measured by established procedures and statistically evaluated. We developed a Manuscript Information Score (MIS) and included only publications which provided enough information for proper interpretation (MIS>5). A formalised Study Methods Evaluation Procedure (SMEP) was used to evaluate these studies, and the subgroup of studies with adequate controls to identify specific effects. A total of 86 studies in 79 publications was identified, 43 studies included statistics, 29 had MIS>5, and 15 studies investigated the specificity of homeopathic preparations. Specific effects of decimal, centesimal and fifty millesimal potencies were found including dilution levels far beyond the Avogadro number. In consecutive series of potencies only some of the tested potencies showed effects. There were many individual studies with diverse methods and very few reproduction trials. Healthy plant models seem an useful approach to investigate basic research questions about the specificity of homeopathic preparations. More investigations with more advanced methods are recommended, especially in the sectors of potentisation techniques, effective potency levels and conditions for reproducibility. Systematic negative control experiments should become a routine procedure to control the stability of the experimental systems

Use of homeopathic preparations in experimental studies with healthy plants

BACKGROUND: The last comprehensive review of experimental research on effects of homeopathic treatments on plants was published in 1984, and lacked formal predefined criteria to assess study quality. Since then several new studies with more advanced methods have been published. OBJECTIVES: To compile a review of the literature on basic research in homeopathy with healthy plants with particular reference to studies investigating specific effects of homeopathic remedies. METHODS: The literature search included English, French, German, Italian, Portuguese and Spanish publications from 1920 to April 2009, using predefined selection criteria. We included experiments with healthy whole plants, seeds, plant parts and cells. The outcomes had to be measured by established procedures and statistically evaluated. We developed a Manuscript Information Score (MIS) and included only publications which provided enough information for proper interpretation (MIS>or=5). A formalised Study Methods Evaluation Procedure (SMEP) was used to evaluate these studies, and the subgroup of studies with adequate controls to identify specific effects. RESULTS: A total of 86 studies in 79 publications was identified, 43 studies included statistics, 29 had MIS>or=5, and 15 studies investigated the specificity of homeopathic preparations. Specific effects of decimal, centesimal and fifty millesimal potencies were found including dilution levels far beyond the Avogadro number. In consecutive series of potencies only some of the tested potencies showed effects. There were many individual studies with diverse methods and very few reproduction trials. CONCLUSIONS: Healthy plant models seem an useful approach to investigate basic research questions about the specificity of homeopathic preparations. More investigations with more advanced methods are recommended, especially in the sectors of potentisation techniques, effective potency levels and conditions for reproducibility. Systematic negative control experiments should become a routine procedure to control the stability of the experimental systems

Use of homeopathic preparations in experimental studies with abiotically stressed plants

Background: Experimental research on the effects of homeopathic treatments on impaired plants was last reviewed in 1990. Objectives: To compile a systematic review of the existing literature on basic research in homeopathy with abiotically stressed plants using predefined criteria. Methods: The literature search was carried out on publications that reported experiments on homeopathy using abiotically stressedwhole plants, seeds, plant parts and cells from 1920 to 2010. Outcomes had to be measured by established procedures and statistically evaluated. Using of a Manuscript Information Score (MIS) we identified those publications that provided sufficient information for proper interpretation (MIS ‡ 5). A further evaluation was based on the use of adequate controls to investigate specific effects of homeopathic preparations and on the use of systematic negative control experiments. Results: A total of 34 publications with abiotically stressed plants was identified, published between 1965 and 2010. The 34 publications described a total of 37 experimental studies. Twenty-two studies included statistics, 13 had a MIS ‡ 5, 8 were identified with adequate controls and 4 with negative control experiments. Significant and reproducible effects with decimal and centesimal potencies were found, including dilution levels beyond Avogadro’s number. One experimental model was independently assessed by another research team and yielded inverted results compared to the original trial. Conclusions: Abiotically stressed plant models seem to be a useful approach to investigate homeopathic basic research questions, but more experimentation and especially more independent replication trials are needed. Systematic negative control experiments should be implemented on a routine basis to exclude false-positive results