1,589 research outputs found
Inferences from inventories of microbes in ecological vineyard settings
The effect of degraded soil conditions on microbial communities associating the rhizosphere and roots of grapevines was investigated within the frame of project CORE Organic Plus ReSolVe. Several relationships based on Dice cluster analyses of DGGE gel profiles suggest that fungal and bacterial communities from degraded and non-degraded areas differ. Results also suggest that composted organic amendments had an effect on community structures. However, the comparison of diversity indexes did not show differences between degraded and non-degraded plots. They suggested rich and even diversity of bacteria and fungi in any of the tested samples. Culture dependent analysis emphasized that a high diversity of Streptomyces spp. associates grapevine roots in degraded and non-degraded areas. Streptomyces species, best known for their potential to produce antibiotics, are increasingly depicted as beneficial plant associated bacteria
Hyperfine structure in the sequence of sodium S states
The hyperfine structure for the 6, 7 and 8 2 S 1/2 states of 23 Na was measured by optical double-resonance techniques. The states were populated by step-wise excitation using two CW dye lasers. For the dipole interaction constant a, a(6 2 S 1/2 ) = 37.5(2) MHz, a(7 2 S 1/2 )=20.9(1) MHz, a(8 2 S 1/2 )=12.85(10) MHz. were obtained. Theoretical calculations of the hyperfine structure were performed for the 3-8 2 S 1/2 states using many-body perturbation techniques. When polarization as well as certain correlation effects are included in the calculation, an agreement with the experimental values within 2% is obtained
Snyder noncommutative space-time from two-time physics
We show that the two-time physics model leads to a mechanical system with
Dirac brackets consistent with the Snyder noncommutative space. An Euclidean
version of this space is also obtained and it is shown that both spaces have a
dual system describing a particle in a curved space-time.Comment: 5 pages, RevTeX4. References adde
Protocols for soil functionality assessment in vineyards
The purpose of this guideline is to describe the methods used during ReSolVe project for soil functionality assessment, so they can be implemented in similar studies.
A brief introduction first underlines what are the main functions of soil and why maintaining an optimal soil functionality is particularly of major interest in viticulture.
Then the different protocols selected for ReSolVe project and this guideline are presented according to the following classification:
- Part I: assessment of soil physical and chemical features;
- Part II: assessment of soil biological features (ecosystem service provision and providers);
- Part III: assessment of rhizosphere biological features;
- Part IV: assessment of grapevine quantitative and qualitative indicators reflecting soil functionality.
In each part, global objectives of the monitoring are explained (what is it used for, in which casesâŠ) and the parameters to evaluate are listed with their corresponding methodological sheet.
In these sheets, instructions and information are given about:
- Materials needed to perform the sampling and the measurement
- Sampling procedure
- Analysis procedure
- Possible interpretations and conclusions that can be drawn (value and meaning of the results, indication of reference values when existing, potential limit of the protocol)
- Bibliographic references related to the method described
- Additional helpful information where appropriate (ex: template of sampling sheet
Protocol for soil functionality assessment in vineyards
Protocols used by Resolve partners during the project, to assess soil functionality on degraded aeras and evaluate soil restoration after applying recovering practices
Protocol for soil functionality assessment in vineyards
Protocols used by Resolve partners during the project, to assess soil functionality on degraded aeras and evaluate soil restoration after applying recovering practices
A bolometric measurement of the antineutrino mass
High statistics calorimetric measurements of the beta spectrum of 187Re are
being performed with arrays of silver perrhenate crystals operated at low
temperature. After a modification of the experimental set-up, which allowed to
substantially reduce the background of spurious counts and therefore to
increase the sensitivity on the electron antineutrino mass, a new measurement
with 10 silver perrhenate microbolometers is running since July 2002. The
crystals have masses between 250 and 350 micrograms and their average FWHM
energy resolution, constantly monitored by means of fluorescence X-rays, is of
28.3 eV at the beta end-point. The Kurie plot collected during 4485 hours x mg
effective running time has an end-point energy of 2466.1 +/- 0.8{stat} +/- 1.5
{syst} eV, while the half lifetime of the decay is found to be 43.2 +/-
0.2{stat} +/- 0.1{syst} Gy. These values are the most precise obtained so far
for 187Re. From the fit of the Kurie plot we can deduce a value for the squared
electron antineutrino mass m(nu)^2 of 147 +/- 237{stat} +/- 90{syst} eV^2. The
corresponding 90% C.L. upper limit for m(nu) is 21.7 eV.Comment: 3 pages, 3 figures. Submitted to Phys. Rev. Let
Hyperfine-structure study in the P sequence of 23 Na using quantum-beam spectroscopy
Describes use of the quantum-beat method to study hyperfine structure in the 5 2 P 3/2 and 6 2 P 3/2 states of 23 Na. A pulsed dye laser, frequency-doubled into the UV region, was used to excite sodium atoms abruptly in a beam. The fluorescent light was recorded with a fast transient digitiser, interfaced to a micro-computer. Theoretical calculations using many-body perturbation theory were performed for the entire P sequence measured so far, taking polarisation and correlation effects into account separately. Very good agreement between experimental and theoretical values was obtained
Malaria diagnosis and treatment practices following introduction of rapid diagnostic tests in Kibaha District, Coast Region, Tanzania
Background: The success of the universal parasite-based malaria testing policy for fever patients attending primary health care (PHC) facilities in Tanzania will depend highly on health workers\u27 perceptions and practices. The aim of this study was, therefore, to assess the present use of malaria diagnostics (rapid diagnostic tests (RDTs) and microscopy), prescription behaviour and factors affecting adherence to test results at PHC facilities in Kibaha District, Coast Region, Tanzania.
Methods: Exit interviews were conducted with fever patients at PHC facilities and information on diagnostic test performed and treatment prescribed were recorded. Interviews with prescribers to assess their understanding, perceptions and practices related to RDTs were conducted, and health facility inventory performed to assess availability of staff, diagnostics and anti-malarial drugs.
Results: The survey was undertaken at ten governmental PHC facilities, eight of which had functional diagnostics. Twenty health workers were interviewed and 195 exit interviews were conducted with patients at the PHC facilities. Of the 168 patients seen at facilities with available diagnostics, 105 (63%) were tested for malaria, 31 (30%) of whom tested positive. Anti-malarial drugs were prescribed to all patients with positive test results, 14% of patients with negative results and 28% of patients not tested for malaria. Antibiotics were more likely to be prescribed to patients with negative test results compared to patients with positive results (81 vs 39%, p \u3c 0.01) and among non-tested compared to those tested for malaria (84 vs 69%, p = 0.01). Stock-outs of RDTs and staff shortage accounted for the low testing rate, and health worker perceptions were the main reason for non-adherence to test results.
Conclusions: Anti-malarial prescription to patients with negative test results and those not tested is still practiced in Tanzania despite the universal malaria testing policy of fever patients. The use of malaria diagnostics was also associated with higher prescription of antibiotics among patients with negative results. Strategies to address health system factors and health worker perceptions associated with these practices are needed. © 2013 Mubi et al.; licensee BioMed Central Ltd
Usefulness of Plasmodium falciparum-specific rapid diagnostic tests for assessment of parasite clearance and detection of recurrent infections after artemisinin-based combination therapy
Background: Rapid diagnostic test (RDT) is an important tool for parasite-based malaria diagnosis. High specificity of RDTs to distinguish an active Plasmodium falciparum infection from residual antigens from a previous infection is crucial in endemic areas where residents are repeatedly exposed to malaria. The efficiency of two RDTs based on histidine-rich protein 2 (HRP2) and lactate dehydrogenase (LDH) antigens were studied and compared with two microscopy techniques (Giemsa and acridine orange-stained blood smears) and real-time polymerase chain reaction (PCR) for assessment of initial clearance and detection of recurrent P. falciparum infections after artemisinin-based combination therapy (ACT) in a moderately high endemic area of rural Tanzania.
Methods: In this exploratory study 53 children \u3c five years with uncomplicated P. falciparum malaria infection were followed up on nine occasions, i.e., day 1, 2, 3, 7, 14, 21, 28, 35 and 42, after initiation of artemether-lumefantrine treatment. At each visit capillary blood samples was collected for the HRP2 and LDH-based RDTs, Giemsa and acridine orange-stained blood smears for microscopy and real-time PCR. Assessment of clearance times and detection of recurrent P. falciparum infections were done for all diagnostic methods.
Results: The median clearance times were 28 (range seven to \u3e42) and seven (two to 14) days for HRP2 and LDH-based RDTs, two (one to seven) and two (one to 14) days for Giemsa and acridine orange-stained blood smear and two (one to 28) days for real-time PCR. RDT specificity against Giemsa-stained blood smear microscopy was 21% for HRP2 on day 14, reaching 87% on day 42, and â„96% from day 14 to 42 for LDH. There was no significant correlation between parasite density at enrolment and duration of HRP2 positivity (r = 0.13, p = 0.34). Recurrent malaria infections occurred in ten (19%) children. The HRP2 and LDH-based RDTs did not detect eight and two of the recurrent infections, respectively.
Conclusion: The LDH-based RDT was superior to HRP2-based for monitoring of treatment outcome and detection of recurrent infections after ACT in this moderately high transmission setting. The results may have implications for the choice of RDT devices in similar transmission settings for improved malaria case management. Trial registration. Clinicaltrials.gov, NCT01843764. © 2013 Aydin-Schmidt et al.; licensee BioMed Central Ltd
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