72 research outputs found
First Results from ABRACADABRA-10cm: A Search for Low-Mass Axion Dark Matter
The presence of dark matter provides some of the most tangible evidence for
the existence of physics beyond the Standard Model. One compelling dark matter
candidate is the axion, a light boson that was originally postulated as a
solution to another outstanding issue, the strong CP problem in QCD.
ABRACADABRA is an experimental program to search for sub-eV axion and
axion-like dark matter. It searches for axion-induced modifications to
Maxwell's equations with a toroidal magnet and SQUID magnetometer. This
contribution will present the first results from the prototype detector,
ABRACADABRA-10cm.Comment: 6 pages, 3 figures, contribution to the 2019 EW session of the 54th
Rencontres de Morion
Magnet Simulations for ABRACADABRA
The axion is a hypothetical particle that can solve the strong CP problem and that may be dark matter. The proposed experiment ABRACADABRA (A Broadband/Resonant Approach to Cosmic Axion Detection with an Amplifying B-field Ring Apparatus) hopes to find the axion through its coupling to a strong magnetic field. This coupling can be interpreted as an effective current inside a toroidal magnet that can then be amplified and detected via an inductively coupled SQUID. The inductive coupling can be either broadband or resonantly tuned to match the (as yet unknown) axion mass. The expected electromagnetic coupling of the axion in the searched mass range is very small (g[αγγ]≲10[-15] GeV[-1]) and so the experiment must be highly sensitive and all sources of noise must be examined and minimized. Before the experiment is built, a smaller, prototype version will be tested and the fields and possible noise sources are being simulated. This thesis presents simulations of various magnet designs and explores their effect on the resulting magnetic fields.Bachelor of Scienc
Klotho and vitamin D in multiple sclerosis: an Italian study
Introduction
Low vitamin D levels have been recognised as an important risk factor for autoimmune diseases, including multiple sclerosis (MS). MS is a multifactorial disease, the pathogenesis of which contributes both to genetic and environmental factors. Polymorphisms in genes codifying molecules involved in vitamin D homeostasis have been associated with hypovitaminosis D. However, the influence of polymorphisms of Klotho, which codify a protein with a pivotal role in vitamin D metabolism, have never been investigated. The aim of this study was to evaluate the association among genetic variants of Klotho, namely rs1207568 and rs9536314, serum 25(OH)D3 levels, and multiple sclerosis (both risk and disease progression).
Material and methods
107 patients with MS and 133 healthy controls were enrolled in this study. Serum 25(OH)D3 levels and genotyping of Klotho SNPs were evaluated in all participants by high-performance liquid chromatography and real-time polymerase chain reaction, respectively.
Results
Allelic and genotypic frequencies did not differ between patients and controls. Concerning rs1207568, we found a trend toward lower serum 25(OH)D3 levels in MS patients with A allele (mutant), both in heterozygosis (AG) and in homozygosis (AA), in comparison to MS patients with G allele in homozygosis (GG) (AG + AA 20.5 ±6.3 µg/l; GG 22.5 ±7.5 µg/l, p = 0.07).
Conclusions
Our findings did not identify a role of Klotho in the genetic susceptibility to MS
Detecting axion dark matter beyond the magnetoquasistatic approximation
A number of proposals have been put forward for detecting axion dark matter
(DM) with grand unification scale decay constants that rely on the conversion
of coherent DM axions to oscillating magnetic fields in the presence of static,
laboratory magnetic fields. Crucially, such experiments \unicode{x2013}
including ABRACADABRA \unicode{x2013} have to-date worked in the limit that
the axion Compton wavelength is larger than the size of the experiment, which
allows one to take a magnetoquasistatic (MQS) approach to modeling the axion
signal. We use finite element methods to solve the coupled
axion-electromagnetism equations of motion without assuming the MQS
approximation. We show that the MQS approximation becomes a poor approximation
at frequencies two orders of magnitude lower than the naive MQS limit.
Radiation losses diminish the quality factor of an otherwise high- resonant
readout circuit, though this may be mitigated through shielding and minimizing
lossy materials. Additionally, self-resonances associated with the detector
geometry change the reactive properties of the pickup system, leading to two
generic features beyond MQS: there are frequencies that require an inductive
rather than capacitive tuning to maintain resonance, and the detector itself
becomes a multi-pole resonator at high frequencies. Accounting for these
features, competitive sensitivity to the axion-photon coupling may be extended
well beyond the naive MQS limit.Comment: 6+5 pages, 3+9 figure
The Superconducting Quasiparticle-Amplifying Transmon: A Qubit-Based Sensor for meV Scale Phonons and Single THz Photons
With great interest from the quantum computing community, an immense amount
of R&D effort has been invested into improving superconducting qubits. The
technologies developed for the design and fabrication of these qubits can be
directly applied to applications for ultra-low threshold particle detectors,
e.g. low-mass dark matter and far-IR photon sensing. We propose a novel sensor
based on the transmon qubit architecture combined with a signal-enhancing
superconducting quasiparticle amplification stage. We refer to these sensors as
SQUATs: Superconducting Quasiparticle-Amplifying Transmons. We detail the
operating principle and design of this new sensor and predict that with minimal
R&D effort, solid-state based detectors patterned with these sensors can
achieve sensitivity to single THz photons, and sensitivity to
phonons in the detector absorber substrate on the timescale.Comment: 6 pages main, 8 pages appendix, 12 figures. Added new appendix on
signal and readout bandwidth. Submitted to PR
The Rapid Identification of Anoplophora chinensis (Coleoptera: Cerambycidae) From Adult, Larval, and Frass Samples Using TaqMan Probe Assay
A molecular diagnostic method using TaqMan probe qPCR is presented for the identification of Anoplophora chinensis (Förster) (Coleoptera: Cerambycidae) from whole body insects (adults and larvae) and frass samples stored under different conditions. The results showed a perfect amplification of DNA from all samples; the repeatability and reproducibility of the protocol were very good, with standard deviations of inter-run and intrarun variability less than or equal to 0.5. The assay allowed to discern all A. chinensis samples from those of the other non-target wood-borer species, with 100% correspondence to the homologous sequences. No amplification or cross reactions were observed with A. glabripennis (Motschulsky) (Coleoptera: Cerambycidae), which is the most related species among those tested. The protocol was validated by an internal blind panel test which showed a good correspondence between the results obtained by different operators in the same lab. The analytical sensitivity for the lab frass with the Probe qPCR, namely the lowest amount of A. chinensis DNA that can be detected (LoD), was 0.64 pg/μl with a Cq of 34.87. The use of indirect evidence for the identification of a pest is an important feature of the method, which could be crucial to detect the presence of wood-boring insects.
This diagnostic tool can help prevent the introduction of A. chinensis into new environments or delimit existing outbreak areas thanks to indirect frass diagnosis
First record of Aleurocanthus camelliae Kanmiya & Kasai, 2011 (Hemiptera, Aleyrodidae) from Italy, on ornamental Camellia spp. plants
This paper provides a first report of Aleurocanthus camelliae, the Camellia spiny whitefly, from Italy. The pest was found on plants of Camellia spp. grown in the nursery. Brief morphological and biological information is provided on this whitefly, as well as some considerations on the phytosanitary measures to be adopted to reduce the potential risk of its spread on ornamental plants in Europe and the EPPO region
Rapid Detection of Pityophthorus juglandis (Blackman) (Coleoptera, Curculionidae) with the Loop-Mediated Isothermal Amplification (LAMP) Method
The walnut twig beetle Pityophthorus juglandis is a phloem-boring bark beetle responsible, in association with the ascomycete Geosmithia morbida, for the Thousand Cankers Disease (TCD) of walnut trees. The recent finding of TCD in Europe prompted the development of effective diagnostic protocols for the early detection of members of this insect/fungus complex. Here we report the development of a highly efficient, low-cost, and rapid method for detecting the beetle, or even just its biological traces, from environmental samples: the loop-mediated isothermal amplification (LAMP) assay. The method, designed on the 28S ribosomal RNA gene, showed high specificity and sensitivity, with no cross reactivity to other bark beetles and wood-boring insects. The test was successful even with very small amounts of the target insect’s nucleic acid, with limit values of 0.64 pg/µL and 3.2 pg/µL for WTB adults and frass, respectively. A comparison of the method (both in real time and visual) with conventional PCR did not display significant differences in terms of LoD. This LAMP protocol will enable quick, low-cost, and early detection of P. juglandis in areas with new infestations and for phytosanitary inspections at vulnerable sites (e.g., seaports, airports, loading stations, storage facilities, and wood processing companies)
A duplex real-time PCR with probe for simultaneous detection of Geosmithia morbida and its vector Pityophthorus juglandis
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