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1.
Eur Phys J Plus ; 138(1): 100, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36741916

RESUMO

The CRESST experiment employs cryogenic calorimeters for the sensitive measurement of nuclear recoils induced by dark matter particles. The recorded signals need to undergo a careful cleaning process to avoid wrongly reconstructed recoil energies caused by pile-up and read-out artefacts. We frame this process as a time series classification task and propose to automate it with neural networks. With a data set of over one million labeled records from 68 detectors, recorded between 2013 and 2019 by CRESST, we test the capability of four commonly used neural network architectures to learn the data cleaning task. Our best performing model achieves a balanced accuracy of 0.932 on our test set. We show on an exemplary detector that about half of the wrongly predicted events are in fact wrongly labeled events, and a large share of the remaining ones have a context-dependent ground truth. We furthermore evaluate the recall and selectivity of our classifiers with simulated data. The results confirm that the trained classifiers are well suited for the data cleaning task.

2.
Appl Radiat Isot ; 194: 110704, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36731392

RESUMO

Core-collapse Supernovae (SNe) are one of the most energetic events in the Universe, during which almost all the star's binding energy is released in the form of neutrinos. These particles are direct probes of the processes occurring in the stellar core and provide unique insights into the gravitational collapse. RES-NOVA will revolutionize how we detect neutrinos from astrophysical sources, by deploying the first ton-scale array of cryogenic detectors made from archaeological lead. Pb offers the highest neutrino interaction cross-section via coherent elastic neutrino-nucleus scattering (CEνNS). Such process will enable RES-NOVA to be equally sensitive to all neutrino flavours. For the first time, we propose the use archaeological Pb as sensitive target material in order to achieve an ultra-low background level in the region of interest (O(1 keV)). All these features make possible the deployment of the first cm-scale neutrino telescope for the investigation of astrophysical sources. In this contribution, we will characterize the radiopurity level and the performance of a small-scale proof-of-principle detector of RES-NOVA, consisting in a PbWO4 crystal made from archaeological-Pb operated as cryogenic detector.

3.
Appl Radiat Isot ; 193: 110681, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36669266

RESUMO

Next-generation experiments searching for rare events must satisfy increasingly stringent requirements on the bulk and surface radioactive contamination of their active and structural materials. The measurement of surface contamination is particularly challenging, as no existing technology is capable of separately measuring parts of the 232Th and 238U decay chains that are commonly found to be out of secular equilibrium. We will present the results obtained with a detector prototype consisting of 8 silicon wafers of 150 mm diameter instrumented as bolometers and operated in a low-background dilution refrigerator at the Gran Sasso Underground Laboratory of INFN, Italy. The prototype was characterized by a baseline energy resolution of few keV and a background <100 nBq/cm2 in the full range of  α energies, obtained with simple procedures for cleaning of all employed materials and no specific measures to prevent recontamination. Such performance, together with the modularity of the detector design, demonstrate the possibility to realize an alpha detector capable of separately measuring all alpha emitters of the 232Th and 238U chains, possibly reaching a sensitivity of few nBq/cm2.

4.
Appl Radiat Isot ; 194: 110670, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36696751

RESUMO

CRESST is a leading direct detection sub-GeVc-2 dark matter experiment. During its second phase, cryogenic bolometers were used to detect nuclear recoils off the CaWO4 target crystal nuclei. The previously established electromagnetic background model relies on Secular Equilibrium (SE) assumptions. In this work, a validation of SE is attempted by comparing two likelihood-based normalisation results using a recently developed spectral template normalisation method based on Bayesian likelihood. Albeit we find deviations from SE in some cases we conclude that these deviations are artefacts of the fit and that the assumptions of SE is physically meaningful.

5.
Zootaxa ; 5195(4): 361-372, 2022 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37045283

RESUMO

The last immature instar and the mature larva of Bocchus scobiolae are described and illustrated for the first time. The affinities of both immature and mature larvae of Bocchus scobiolae and Mystrophorus formicaeformis are discussed to define larval characters of the subfamily Bocchinae.


Assuntos
Himenópteros , Animais , Larva
6.
Eur Phys J C Part Fields ; 79(10): 881, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31708682

RESUMO

The CRESST (Cryogenic Rare Event Search with Superconducting Thermometers) dark matter search experiment aims for the detection of dark matter particles via elastic scattering off nuclei in CaWO 4 crystals. To understand the CRESST electromagnetic background due to the bulk contamination in the employed materials, a model based on Monte Carlo simulations was developed using the Geant4 simulation toolkit. The results of the simulation are applied to the TUM40 detector module of CRESST-II phase 2. We are able to explain up to ( 68 ± 16 ) % of the electromagnetic background in the energy range between 1 and 40 keV .

7.
Braz J Biol ; 75(2): 455-9, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-26132032

RESUMO

Two new species of Dryinidae are described and illustrated Dryinus auratus Martins, Lara, Perioto & Olmi sp. nov. and Gonatopus mariae Martins, Lara, Perioto & Olmi sp. nov., both from areas of Atlantic Rainforest at São Paulo State, Brazil. Keys to species are provided.


Assuntos
Vespas/anatomia & histologia , Vespas/classificação , Animais , Brasil , Feminino , Masculino , Floresta Úmida
8.
Braz. j. biol ; 75(2): 455-459, 05/2015. graf
Artigo em Inglês | LILACS | ID: lil-749682

RESUMO

Two new species of Dryinidae are described and illustrated Dryinus auratus Martins, Lara, Perioto & Olmi sp. nov. and Gonatopus mariae Martins, Lara, Perioto & Olmi sp. nov., both from areas of Atlantic Rainforest at São Paulo State, Brazil. Keys to species are provided. .


Duas novas espécies de Dryinidae (Hymenoptera: Chrysidoidea) de áreas de Mata Atlântica do Estado de São Paulo, Brasil. Duas novas espécies de Dryinidae (Hymenoptera: Chrysidoidea) são descritas e ilustradas: Dryinus auratus Martins, Lara, Perioto & Olmi sp. nov. e Gonatopus mariae Martins, Lara, Perioto & Olmi sp. nov., ambas provenientes de áreas de Mata Atlântica do Estado de São Paulo, Brasil. São fornecidas chaves para as espécies.


Assuntos
Animais , Feminino , Masculino , Vespas/anatomia & histologia , Vespas/classificação , Brasil , Floresta Úmida
9.
Ann Ist Super Sanita ; 34(1): 137-43, 1998.
Artigo em Italiano | MEDLINE | ID: mdl-9679352

RESUMO

There is a high density of industries for the production of ceramic tiles in the District of Scandiano (province of Reggio Emilia, Emilia Romagna region). In this area, since the beginning of 1970s, the time trend of Pb exposure in ceramic tile plants has been evaluated by means of biological monitoring (BM) data collected at the Service of Prevention and Safety in the Work Environment and its associated Toxicology Laboratory. From these data, a clear decreasing time trend of exposure levels is documented, the reduction being more evident during the seventies and in 1985-88. During the seventies BM was introduced systematically in all ceramic tile plants with the determination of delta-aminolevulinic acid in urine (ALA-U). As a consequence of the BM programme, hygienic measures for the abatement of pollution inside the plants were implemented, and a reduction, from 20.6% to 2%, of ALA-U values exceeding 10 mg/l, was observed. In 1985, the determination of lead in blood (PbB) replaced that of ALA-U in the BM programmes and highlighted the persistence of high level of exposure to Pb, which could not be outlined by means of ALA-U because of its lower sensitivity. PbB levels were 36.1 micrograms/100 ml and 25.7 micrograms/100 ml in male and female workers, respectively. These results required the implementation, within the plants, of additional hygienic measures and a significant reduction of PbB was obtained in the following three years. In 1988 PbB levels were 26.0 +/- 10.7 and 21.6 +/- 10.3 micrograms/100 ml in male and female workers, respectively. In 1993-95 Pb levels were obtained from 1328 male and 771 female workers of 56 plants, accounting for about 40% of the total number of workers in the ceramic industry, in the zones of Sassuolo and Scandiano. Exposure levels are not different from those observed in the preceding years, with PbB levels of 25.3 +/- 11.1 and 19.1 +/- 9.2 micrograms/100 ml in male and female workers, respectively.


Assuntos
Poluentes Ocupacionais do Ar/análise , Cerâmica , Monitoramento Ambiental , Indústrias , Chumbo/sangue , Exposição Ocupacional , Adulto , Poluentes Ocupacionais do Ar/efeitos adversos , Poluição do Ar/prevenção & controle , Ácido Aminolevulínico/urina , Biomarcadores , Monitoramento Epidemiológico , Feminino , Humanos , Chumbo/efeitos adversos , Intoxicação por Chumbo/epidemiologia , Intoxicação por Chumbo/prevenção & controle , Masculino , Programas de Rastreamento , Concentração Máxima Permitida , Pessoa de Meia-Idade , Doenças Profissionais/induzido quimicamente , Doenças Profissionais/epidemiologia , Doenças Profissionais/prevenção & controle , Ocupações , Fatores de Tempo
10.
Ital J Neurol Sci ; 18(2): 87-92, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9239528

RESUMO

We determined whole blood lead and cadmium levels, and serum selenium levels in patients with sporadic amyotrophic lateral sclerosis and age- and sex-matched controls. Disability due to the disease directly correlated with lead levels, and there was a strong inverse correlation with selenium concentrations. Lead and selenium concentrations tended to be similar in the cases and controls, both in the study population as a whole and after the removal from the analysis of the patients with the highest degree of disability. In the patients with limited disability, cadmium concentrations were higher than in the controls. Our findings lend limited support to a possible involvement of cadmium, but not lead, in the etiology of sporadic amyotrophic lateral sclerosis, and strongly suggest that short-term indicators of exposure are inadequate to investigate the relationship between selenium and the disease.


Assuntos
Esclerose Lateral Amiotrófica/sangue , Cádmio/sangue , Chumbo/sangue , Selênio/sangue , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco
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