225 research outputs found
Beta-delayed-neutron studies of Sb and I performed with trapped ions
Beta-delayed-neutron (n) spectroscopy was performed using the
Beta-decay Paul Trap and an array of radiation detectors. The n
branching ratios and energy spectra for Sb and I were
obtained by measuring the time of flight of recoil ions emerging from the
trapped ion cloud. These nuclei are located at the edge of an isotopic region
identified as having n branching ratios that impact the r-process
abundance pattern around the A~130 peak. For Sb and I,
n branching ratios of 14.6(11)%, 17.6(28)%, and 7.6(28)% were
determined, respectively. The n energy spectra obtained for Sb
and I are compared with results from direct neutron measurements, and
the n energy spectrum for Sb has been measured for the first
time
Astrophysical structures from primordial quantum black holes
The characteristic sizes of astrophysical structures, up to the whole
observed Universe, can be recovered, in principle, assuming that gravity is the
overall interaction assembling systems starting from microscopic scales, whose
order of magnitude is ruled by the Planck length and the related Compton
wavelength. This result agrees with the absence of screening mechanisms for the
gravitational interaction and could be connected to the presence of Yukawa
corrections in the Newtonian potential which introduce typical interaction
lengths. This result directly comes out from quantization of primordial black
holes and then characteristic interaction lengths directly emerge from quantum
field theory.Comment: 11 page
The use of cosmic-ray muons in the energy calibration of the Beta-decay Paul Trap silicon-detector array
This article presents an approach to calibrate the energy response of double-sided silicon strip detectors (DSSDs) for low-energy nuclear-science experiments by utilizing cosmic-ray muons. For the 1-mm-thick detectors used with the Beta-decay Paul Trap, the minimum-ionizing peak from these muons provides a stable and time-independent in situ calibration point at around 300 keV, which supplements the calibration data obtained above 3 MeV from ฮฑ sources. The muon-data calibration is achieved by comparing experimental spectra with detailed Monte Carlo simulations performed using GEANT4 and CRY codes. This additional information constrains the calibration at lower energies, resulting in improvements in quality and accuracy
Recoil ions from the ฮฒ decay of Sb 134 confined in a Paul trap
The low-energy recoiling ions from the ฮฒ decay of Sb134 were studied by using the Beta-decay Paul Trap. Using this apparatus, singly charged ions were suspended in vacuum at the center of a detector array used to detect emitted ฮฒ particles, ฮณ rays, and recoil ions in coincidence. The recoil ions emerge from the trap with negligible scattering, allowing ฮฒ-decay properties and the charge-state distribution of the daughter ions to be determined from the ฮฒ-ion coincidences. First-forbidden ฮฒ-decay theory predicts a ฮฒ-ฮฝ correlation coefficient of nearly unity for the 0- to 0+ transition from the ground state of Sb134 to the ground state of Te134. Although this transition was expected to have a nearly 100% branching ratio, an additional 17.2(52)% of the ฮฒ-decay strength must populate high-lying excited states to obtain an angular correlation consistent with unity. The extracted charge-state distribution of the recoiling ions was compared with existing ฮฒ-decay results and the average charge state was found to be consistent with the results from lighter nuclei
ฮฒ-delayed neutron emission studies of i 137,138 and Cs 144,145 performed with trapped ions
A detailed study of the ฮฒ-delayed neutron emission properties of I137,138 and Cs144,145 has been performed by confining ions in the Beta-decay Paul Trap. The daughter ions following ฮฒ decay emerge from the trapped-ion cloud with negligible scattering allowing reconstruction of the recoil-ion energy from the time of flight. From this information, the neutron-emission branching ratios and neutron-energy spectra were deduced. The results for the I137 and Cs144,145 decays are in agreement with previous results performed using direct neutron-detection techniques. In the case of I138, a branching ratio of 6.18(50)% is obtained, yielding a value consistent with the more recent results, which are a factor of two larger than measurements made prior to 1978
Transition of care: experiences and preferences of patients across the primary/secondary interface โ a qualitative study
BACKGROUND: Coordination between care providers of different disciplines is essential to improve the quality of care, in particular for patients with chronic diseases. The way in which general practitioners (GP's) and medical specialists interact has important implications for any healthcare system in which the GP plays the role of gatekeeper to specialist care. Patient experiences and preferences have proven to be increasingly important in discussing healthcare policy. The Dutch government initiated the development of a special website with information for patients on performance indicators of hospitals as well as information on illness or treatment.In the present study we focus on the transition of care at the primary - secondary interface with reference to the impact of patients' ability to make choices about their secondary care providers. The purpose of this study is to (a) explore experiences and preferences of patients regarding the transition between primary and secondary care, (b) study informational resources on illness/treatment desired by patients and (c) determine how information supplied could make it easier for the patient to choose between different options for care (hospital or specialist). METHODS: We conducted a qualitative study using semi-structured focus group interviews among 71 patients referred for various indications in the north and west of The Netherlands. RESULTS: Patients find it important that they do not have to wait, that they are taken seriously, and receive adequate and individually relevant information. A lack of continuity from secondary to primary care was experienced. The patient's desire for free choice of type of care did not arise in any of the focus groups. CONCLUSION: Hospital discharge information needs to be improved. The interval between discharge from specialist care and the report of the specialist to the GP might be a suitable performance indicator in healthcare. Patients want to receive information, tailored to their own situation. The need for information, however, is quite variable. Patients do not feel strongly about self-chosen healthcare, contrary to what administrators presently believe
The Beta-decay Paul Trap Mk IV: Design and commissioning
The Beta-decay Paul Trap is an open-geometry, linear trap used to measure the
decays of Li and B to search for a tensor contribution to the weak
interaction. In the latest Li measurement of Burkey et al. (2022),
scattering was the dominant experimental systematic uncertainty. The Beta-decay
Paul Trap Mk IV reduces the prevalence of scattering by a factor of 4
through a redesigned electrode geometry and the use of glassy carbon and
graphite as electrode materials. The trap has been constructed and successfully
commissioned with Li in a new data campaign that collected 2.6 million
triple coincidence events, an increase in statistics by 30% with 4 times less
scattering compared to the previous Li data set.Comment: 17 pages, 7 figure
Distinct Peripheral Blood RNA Responses to Salmonella in Pigs Differing in Salmonella Shedding Levels: Intersection of IFNG, TLR and miRNA Pathways
Transcriptomic analysis of the response to bacterial pathogens has been reported for several species, yet few studies have investigated the transcriptional differences in whole blood in subjects that differ in their disease response phenotypes. Salmonella species infect many vertebrate species, and pigs colonized with Salmonella enterica serovar Typhimurium (ST) are usually asymptomatic, making detection of these Salmonella-carrier pigs difficult. The variable fecal shedding of Salmonella is an important cause of foodborne illness and zoonotic disease. To investigate gene pathways and biomarkers associated with the variance in Salmonella shedding following experimental inoculation, we initiated the first analysis of the whole blood transcriptional response induced by Salmonella. A population of pigs (nโ=โ40) was inoculated with ST and peripheral blood and fecal Salmonella counts were collected between 2 and 20 days post-inoculation (dpi). Two groups of pigs with either low shedding (LS) or persistent shedding (PS) phenotypes were identified. Global transcriptional changes in response to ST inoculation were identified by Affymetrix Genechipยฎ analysis of peripheral blood RNA at day 0 and 2 dpi. ST inoculation triggered substantial gene expression changes in the pigs and there was differential expression of many genes between LS and PS pigs. Analysis of the differential profiles of gene expression within and between PS and LS phenotypic classes identified distinct regulatory pathways mediated by IFN-ฮณ, TNF, NF-ฮบB, or one of several miRNAs. We confirmed the activation of two regulatory factors, SPI1 and CEBPB, and demonstrated that expression of miR-155 was decreased specifically in the PS animals. These data provide insight into specific pathways associated with extremes in Salmonella fecal shedding that can be targeted for further exploration on why some animals develop a carrier state. This knowledge can also be used to develop rational manipulations of genetics, pharmaceuticals, nutrition or husbandry methods to decrease Salmonella colonization, shedding and spread
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